HK1246739B - Liquid cartridge - Google Patents

Description

Liquid Box

Technical Field

The present invention relates to a liquid box.

Background Art

Conventional inkjet recording apparatuses known in the art record images on recording media by ejecting ink held in an ink container from a nozzle.Some inkjet recording apparatuses are configured so that a new ink cartridge can be installed each time the ink is exhausted.

Japanese Unexamined Patent Application Publication No. 2014-19130 discloses a cartridge that can be removably attached to a cartridge attachment unit. The cartridge has a circuit board configured to be electrically connected to a contact mechanism provided in the cartridge attachment unit. The presence of ink in the cartridge can be optically detected.

Japanese Unexamined Patent Application Publication No. 2013-49165 discloses an ink cartridge that can be removably attached to a cartridge attachment unit. The ink cartridge has a rotating member. When the rotating member engages with the cartridge attachment unit, the ink cartridge is attached to the cartridge attachment unit and is maintained in an attached state. The ink cartridge has a detection portion for optically detecting the amount of remaining ink. By attaching the ink cartridge to the cartridge attachment unit, the detection portion is detected by an optical sensor provided in the cartridge attachment unit. The ink cartridge has an integrated circuit (IC) board in which information about the ink cartridge has been stored. When the ink cartridge is attached to the cartridge attachment unit, the IC board is electrically connected to a contact provided in the cartridge attachment unit.

Summary of the Invention

A problem with the cartridge having a circuit board and the ink cartridge having an IC board described above is that, when the cartridge or ink cartridge is attached to or detached from the cartridge attachment unit, the circuit board or IC board slides on the contact piece of the cartridge attachment unit, and the conductive member of the circuit board or IC board is cut off, thereby generating shavings. If these shavings adhere to the optical sensor or the portion detected by the sensor, the detection by the sensor may become inaccurate.

The present invention solves the above-mentioned problem and aims to provide a liquid cartridge in which even if shavings are generated from a circuit board, the detection of the state of the liquid stored in the liquid cartridge is less affected. This object is achieved by a liquid cartridge.

According to one embodiment of the present invention, a liquid box includes: a front surface; an upper surface, which faces an upward direction when the liquid box is installed in a liquid consumption device; a liquid outlet portion, which faces a first direction at the front surface; a circuit board, which is arranged on the upper surface; and a liquid detection portion, which is used to detect the state of the liquid stored in the liquid box, wherein the liquid detection portion includes an optical access portion, which is configured to access through light traveling from a first point toward a second point, wherein the optical access portion is arranged above the circuit board in an upward direction.

Therefore, shavings generated from the circuit board are less likely to adhere to the light receiving portion, and even if shavings are generated from the circuit board, detection at the light receiving portion is less affected.

Alternatively, in any of the above liquid cartridges, the circuit board may be displaced from the light receiving portion in the first direction.

Therefore, when the liquid cartridge is inserted into or removed from the liquid cartridge attachment unit, the light receiving portion does not pass through the region where shavings are generated from the circuit board, so the shavings are less likely to adhere to the light receiving portion.

Optionally, in any of the above liquid cartridges, the optical input portion includes a first side surface and a second side surface, wherein each of the first side surface and the second side surface extends in the first direction and intersects with the upper surface.

Therefore, the state of the liquid in the liquid cartridge can be detected through the first side surface and the second side surface.

Optionally, in any of the above-mentioned liquid boxes, the size of the first side surface in the upward direction may be smaller than the size of the first side surface in the first direction, and the size of the second side surface of the optical access portion in the upward direction may be smaller than the size of the second side surface of the optical access portion in the first direction.

Therefore, the size of the light receiving portion in the downward direction and the upward direction is reduced.

Alternatively, any of the above liquid cartridges may include an intervening wall provided between the circuit board and the optical input portion, and the intervening wall includes a designated surface extending in a second direction intersecting the first direction and the upward direction.

Therefore, the intervening wall can block the route of shavings generated from the circuit board moving to the light receiving portion.

Alternatively, in any of the above liquid cartridges, a dimension of the prescribed surface of the intervention wall in the second direction may be longer than a distance between the first side surface and the second side surface of the light receiving portion in the second direction.

Therefore, the intervening wall can further block the route of the shavings generated from the circuit board moving to the light receiving portion.

Alternatively, in any of the above liquid cartridges, a dimension of the intervention wall in the first direction may be longer than a dimension of the intervention wall in the second direction.

Therefore, this makes it more difficult for the shavings to reach the light input portion.

Optionally, in any of the above liquid cartridges, the intervention wall may be provided closer to the light receiving portion than to the circuit board in the first direction.

Therefore, shavings generated from the circuit board can be easily blocked by the intervening wall.

Alternatively, in any of the above liquid cartridges, the liquid detection portion may be configured to change a state of light transmitted from the first point toward the second point and input to the light input portion, according to an amount of liquid stored in the liquid cartridge.

Therefore, the amount of liquid stored in the liquid cartridge can be detected.

Optionally, in any of the above-described liquid cartridges, the light access portion may be configured to allow light traveling from a first point toward a second point to pass through the light access portion, and the liquid detection portion may include a light attenuation portion, a portion of which is configured to be located in the light access portion, wherein the portion of the light attenuation portion is configured to change the state of the light passing through the light access portion depending on whether the amount of liquid stored in the liquid cartridge is less than a specified amount. The entire light attenuation portion may attenuate light, or at least a portion of the light attenuation portion may attenuate light, and other portions of the light attenuation portion may not attenuate light.

Optionally, in any of the above-described liquid cartridges, when the amount of liquid stored in the liquid cartridge is greater than or equal to a specified amount, the portion of the light attenuating portion may be positioned above the circuit board. This makes it more difficult for shavings to reach a height at which light passes through the light detecting portion to detect the amount of liquid stored in the liquid cartridge.

Alternatively, in any of the liquid cartridges described above, when the amount of liquid stored in the liquid cartridge is greater than or equal to a specified amount, the intervening wall may extend upward in an upward direction beyond the portion beyond the light attenuating portion.

Such placement of the intervening wall makes it difficult for shavings generated from the circuit board to reach the position where the portion of the light attenuating portion is detected by the sensor.

Alternatively, in any of the above liquid cartridges, the liquid cartridge may be provided with a recessed portion that is displaced from the circuit board in a third direction opposite to the first direction.

Therefore, shavings generated from the circuit board are collected and retained in the recessed portion.

This makes it difficult to disperse the shavings.

Alternatively, in any of the above liquid cartridges, the center of the circuit board may be disposed closer to the second side surface than to the first side surface.

Therefore, the probability that the chips will reach the second side surface is lower than the probability that the chips will reach the first side surface.

Optionally, in any of the above-mentioned liquid boxes, the liquid box may include a chamber configured to store liquid in the chamber, wherein the light attenuation portion may be a sensor arm configured to rotate around an axis in the chamber, and when the sensor arm rotates, a portion of the sensor arm changes the state of light passing through the light access portion.

Alternatively, in any of the above liquid cartridges, the light-input portion may be made of a transparent material, define an internal space continuous with the chamber, and protrude in an upward direction relative to the upper surface.

The liquid cartridge may include a body defining the chamber and a cover covering the body, and wherein the light-incoming portion may be provided on the body and protrude to the outside of the cover through an opening formed through the cover.

Alternatively, in any of the above liquid cartridges, when the circuit board is viewed upward, the circuit board may overlap with the liquid outlet portion. This enables the liquid cartridge to be designed such that the distance between the circuit board and the light receiving portion is extended.

Optionally, in any of the above-mentioned liquid boxes, the liquid box may include a positioning surface, which is configured to limit the movement of the liquid box in the upward and downward directions, and the positioning surface is arranged above the liquid outlet portion in the upward direction, and the positioning surface is arranged below the circuit board in the upward direction.

Therefore, the circuit board is accurately positioned to the contacts in the downward direction and the upward direction.

Optionally, in any of the above-mentioned liquid boxes, the liquid box can be configured to resist a force directed in a third direction opposite to the first direction and be inserted into the box attachment unit of the liquid consumption device in the first direction, and thereby attached to the box attachment unit in an attached state, and wherein the liquid box may include a locking surface, which is arranged at the upper surface and shifted from the optical access portion in the third direction, and the locking surface is configured to contact the locking portion of the liquid consumption device in the third direction, wherein the optical access portion can be shifted from the circuit board in the third direction.

Therefore, when the liquid cartridge is attached to the cartridge attachment unit, the circuit board, located at the front end in the first direction, is positioned with high accuracy, allowing the circuit board to be securely connected to the contact member. The locking surface, located at the rear end in the first direction, facilitates locking and unlocking operations, i.e., allows for easy rotation about the rotation center. This also reduces the range of rotation of the liquid cartridge for locking and unlocking.

Alternatively, in any of the above liquid cartridges, the liquid cartridge may be configured to rotate between a first orientation and a second orientation, wherein the locking surface is configured to contact the locking portion toward the third direction in the first orientation and is disposed below the locking portion in the second orientation.

Alternatively, in any of the above liquid cartridges, the optical access portion may be arranged closer to the locking surface in the first direction than to the circuit board in the first direction. This allows the liquid cartridge to be designed such that the distance between the circuit board and the optical access portion is extended.

Alternatively, in any of the above-described liquid cartridges, an upper edge of the light receiving portion may be arranged closer to the locking surface than to the circuit board in an upward direction. This makes it easy to ensure an internal space of the liquid cartridge.

Optionally, in any of the above-mentioned liquid boxes, the liquid detection portion may include a prism arranged below the circuit board, wherein the prism is configured to reflect light according to the amount of liquid stored in the liquid box, and wherein the light input portion is configured to reflect light traveling from a first point toward the prism or reflect light reflected at the prism toward a second point.

Alternatively, in any of the above liquid cartridges, a dimension of the circuit board in the first direction may be smaller than a dimension of the circuit board in a direction perpendicular to the first direction and the upward direction.

Optionally, in any of the above liquid cartridges, the circuit board may include a plurality of electrical interfaces, the plurality of electrical interfaces being spaced apart and aligned in the direction and facing in an upward direction.

Alternatively, in any of the liquid cartridges described above, the light receiving portion may be configured to be received by light traveling from a first point toward a second point in a second direction perpendicular to the first direction and the upward direction.

Alternatively, in any of the liquid cartridges described above, the light input portion may be provided at the upper surface.

Optionally, in any of the above liquid cartridges, the liquid detection portion may include a first light attenuation portion.

Optionally, in any of the above liquid boxes, the liquid box may include a second light attenuating portion above the circuit board.

Alternatively, in any of the above liquid cartridges, the circuit board may be displaced upward from the liquid outlet portion by a first distance, and the light receiving portion may be displaced upward from the liquid outlet portion by a second distance greater than the first distance.

With the liquid cartridge according to the present invention, even if shavings are generated from the circuit board, the influence on the detection of the state of the liquid stored in the liquid cartridge is small.

BRIEF DESCRIPTION OF THE DRAWINGS

[ Fig. 1] Fig. 1 is a schematic cross-sectional view schematically showing the internal structure of a printer having a cartridge attachment unit.

[ Fig. 2] Fig. 2 is a front view showing the outer appearance of a cartridge attachment unit.

[Fig. 3A] Fig. 3A is a perspective view showing the outer appearance of the ink cartridge when viewed from the front and from above.

[Fig. 3B] Fig. 3B is a perspective view showing the outer appearance of the ink cartridge when viewed from the front and from below.

[Fig. 4A] Fig. 4A is a perspective view showing the outer appearance of the ink cartridge when viewed from the rear and from above.

[Fig. 4B] Fig. 4B is a perspective view showing the outer appearance of the ink cartridge when viewed from the rear and below.

[Figure 5] Figure 5 is a side view of the ink cartridge.

[Fig. 6] Fig. 6 is a longitudinal cross-sectional view showing the internal structure of the ink cartridge.

[Fig. 7] Fig. 7 is a longitudinal cross-sectional view of the ink cartridge and the cartridge attachment unit, illustrating a state in which the ink cartridge begins to be inserted into the cartridge attachment unit. [Fig.

[Figure 8] Figure 8 is a longitudinal cross-sectional view of the ink cartridge and the cartridge attachment unit, showing a state in which the second protrusion is in contact with the slider.

[Fig. 9] Fig. 9 is a longitudinal cross-sectional view of the ink cartridge and the cartridge attachment unit, illustrating a state in which the ink supply unit begins to enter the guide and the rod begins to enter the recess in the front cover. [Fig.

[Fig. 10] Fig. 10 is a longitudinal cross-sectional view of the ink cartridge and the cartridge attachment unit, illustrating a state in which the ink needle has entered the ink supply opening in the ink supply unit. [Fig.

[Figure 11] Figure 11 is a longitudinal cross-sectional view of the ink cartridge and the cartridge attachment unit, showing a state in which the ink cartridge is positioned in the cartridge attachment unit.

[Figure 12] Figure 12 is a side view of the ink cartridge when the ink cartridge is in the second orientation, showing the relationship of the forces when the user presses the upper portion of the rear surface.

[Figure 13] Figure 13 is a side view of the ink cartridge when the ink cartridge is in the second orientation, showing the relationship of the forces when the user presses the lower portion of the rear surface.

[Figure 14] Figure 14 is a side view of the ink cartridge in a first orientation, showing the relationship between the virtual arc and the locking surface.

[Fig. 15A] Fig. 15A is a plan view of the ink cartridge when viewed downward.

[Fig. 15B] Fig. 15B is a rear view of the ink cartridge when viewed from the front.

[Fig. 16A] Fig. 16A is a perspective view of a modification of the liquid level detecting portion, illustrating a state in which ink in the holding chamber is reduced. [Fig.

[Fig. 16B] Fig. 16B is a perspective view of a modification of the liquid level detecting portion, illustrating a state in which the holding chamber is filled with ink. [Fig.

DETAILED DESCRIPTION

An embodiment of the present invention will be described as appropriate with reference to the accompanying drawings. The embodiment described below is merely an example of implementing the present invention; it should be understood that the embodiment can be appropriately changed without departing from the intended scope of the present invention. In the following description, the direction in which the ink cartridge 30 is inserted into the cartridge attachment unit 110 will be defined as an insertion direction (an example of a first direction) 51, and the direction opposite to the insertion direction 51, that is, the direction in which the ink cartridge 30 is removed from the cartridge attachment unit 110, will be defined as a removal direction (an example of a third direction) 52. Although the insertion direction 51 and the removal direction 52 are horizontal in this embodiment, this is not a limitation; the insertion direction 51 and the removal direction 52 may not be horizontal. The direction of gravity will be defined as a downward direction 53, and the direction opposite to the direction of gravity will be defined as an upward direction 54. Directions orthogonal to the insertion direction 51 and the downward direction 53 will be defined as a right direction 55 and a left direction 56 (an example of a second direction). Specifically, in a state where the ink cartridge 30 has been inserted into the attachment position in the cartridge attachment unit 110, that is, in a state where the ink cartridge 30 is in the attachment orientation (an example of the first orientation and the supply orientation), when the ink cartridge 30 is viewed in the removal direction 52, the direction extending to the right will be defined as the right direction 55, and the direction extending to the left will be the left direction 56. The insertion direction 51 can be referred to as a forward direction 57, and the removal direction 52 can be referred to as a rearward direction 58.

<Overview of Printer 10>

As shown in Figure 1, the printer 10 records an image by selectively ejecting ink droplets onto a recording sheet according to an inkjet recording method. The printer 10 (an example of a liquid consuming device) includes a recording head 21, an ink supply unit 100, and an ink tube 20 interconnecting the recording head 21 and the ink supply unit 100. The ink supply unit 100 includes a box attachment unit 110 (an example of an attachment unit). In the box attachment unit 110, an ink cartridge 30 (an example of a liquid cartridge) can be attached. The box attachment unit 110 has an opening 112 on one surface thereof. The ink cartridge 30 is inserted into the box attachment unit 110 in an insertion direction 51 through the opening 112 and is removed from the box attachment unit 110 in a removal direction 52.

Ink (an example of liquid) that can be used in the printer 10 is held in an ink cartridge 30. In a state where the ink cartridge 30 has been attached to the cartridge attachment unit 110, the ink cartridge 30 and the recording head 21 are interconnected with the ink tube 20. A sub-tank 28 is provided in the recording head 21. The sub-tank 28 temporarily holds ink to be supplied through the ink tube 20. The recording head 21 selectively ejects the ink supplied from the sub-tank 28 from the nozzles 29 according to the inkjet recording method. Specifically, a driving voltage is selectively applied from a head control circuit board provided in the recording head 21 to each piezoelectric device 29A provided corresponding to one nozzle 29.

The printer 10 includes a feed tray 15, a supply roller 23, a transport roller pair 25, a platen 26, a discharge roller pair 27, and a discharge tray 16. A recording sheet is supplied from the feed tray 15 to the transport path 24 by the supply roller 23, and then transported to the platen 26 by the transport roller pair 25. The recording head 21 selectively ejects ink onto the recording sheet as it passes over the platen 26. Thus, an image is recorded on the recording sheet. After passing the platen 26, the recording sheet is discharged by the discharge roller pair 27 to the discharge tray 16, which is located at the downstream end of the transport path 24.

<Ink Supply Unit 100>

As shown in FIG1 , an ink supply unit 100 is provided in the printer 10. The ink supply unit 100 supplies ink to the recording head 21 included in the printer 10. The ink supply unit 100 has a cartridge attachment unit 110 to which the ink cartridge 30 can be attached. FIG1 shows a state in which the ink cartridge 30 has been attached to the cartridge attachment unit 110, that is, a state in which the ink cartridge 30 is in an attachment orientation (a first orientation and a supply orientation).

<Cartridge Attachment Unit 110>

As shown in FIG2 , the cartridge attachment unit 110 can accommodate four ink cartridges 30 corresponding to cyan, magenta, yellow, and black in the housing 101. In addition to the housing 101, as shown in FIG2 and FIG7 , the cartridge attachment unit 110 includes an ink needle 102, a sensor 103, four contacts 106, a slider 107, and a locking portion 145 for each ink cartridge 30.

<Housing 101>

The housing 101 that covers the cartridge attachment unit 110 has a box-like shape, having a top surface defining the top of the interior space of the housing 101, a bottom surface defining the bottom, a rear surface connecting the top and bottom, and an opening 112. The opening 112 is formed at a position where the opening 112 faces rearward in both the insertion direction 51 and the removal direction 52, and the opening 112 can be exposed to the surface of the user interface of the printer 10, which the user faces when using the printer 10. The ink cartridge 30 is inserted into and removed from the housing 101 through the opening 112. When the upper and lower edges of the ink cartridge 30 are inserted into the guide grooves 109 formed in the top and bottom surfaces, the ink cartridge 30 is guided in the insertion direction 51 and the removal direction 52 in Figure 7. In the housing 101, three plates 104 divide the interior space into four vertically elongated spaces. One ink cartridge 30 is accommodated in each of these spaces divided by the plates 104.

<Ink Needle 102>

As shown in Figures 2 and 7, an ink needle (an example of a liquid supply tube) 102 made of a tubular resin is provided at a lower portion of the rear surface of the housing 101. The ink needle 102 is provided at a position on the rear surface of the ink cartridge 101 where it corresponds to the ink supply portion 34 of the ink cartridge 30 attached to the cartridge attachment unit 110. The ink needle 102 protrudes from the rear surface of the housing 101 in the removal direction 52.

A cylindrical guide 105 is provided around the ink needle 102. The guide 105 protrudes from the rear of the housing 101 in the removal direction 52. The end of the protrusion is open. The ink needle 102 is provided at the center of the guide 105. The guide 105 is shaped so as to advance the ink supply portion 34 of the ink cartridge 30 inward.

During the process of inserting the ink cartridge 30 into the cartridge attachment unit 110 in the insertion direction 51, that is, during the process of moving the ink cartridge 30 to the attachment position, the ink supply portion 34 of the ink cartridge 30 enters the guide 105 (see Figure 10). When the ink cartridge 30 is further inserted into the cartridge attachment unit 110 in the insertion direction 51, the ink needle 102 is inserted into the ink supply opening 71 formed in the ink supply portion 34. Therefore, the ink supply valve 70 in the ink supply portion 34 is opened. As a result, the ink needle 102 and the ink supply portion 34 are connected together. Then, the ink retained in the retaining chamber 36 formed in the ink cartridge 30 flows into the ink tube 20 connected to the ink needle 102 through the internal space of the cylindrical wall 73 formed in the ink supply portion 34 and the internal space of the ink needle 102. The tip of the ink needle 102 can be flat or pointed.

<Slider 107>

An opening 111 is formed below the lower guide groove 109 in the housing 101 and at a position close to the rear so as to extend in the insertion direction 51 (or removal direction 52). The slider 107 is provided in the opening 111. The slider 107 protrudes upward through the opening 111 from below the lower guide groove 109. The slider 107 is engaged with a guide rail 113 provided at the lower portion of the housing 101 and can move in the opening 111 along the guide rail 113 in the insertion direction 51 and the removal direction 52. A tension spring 114 extends between the slider 107 and the housing 101. When the slider 107 is pulled, the tension spring 114 generates a biasing force in the removal direction 52. Therefore, in a state where no external force is applied to the slider 107, the slider 107 is located at the end of the guide rail 113 in the removal direction 52. When an external force is applied to the slider 107 at this position in the insertion direction 51 , the slider 107 can move in the opening 111 in the insertion direction 51 along the guide rail 113 .

During the process of inserting the ink cartridge 30 into the cartridge attachment unit 110 in the insertion direction 51, that is, during the process of moving the ink cartridge 30 to the attachment position, the second protrusion 86 formed on the ink cartridge 30 advances along the lower guide groove 109 in the insertion direction 51 and contacts the slider 107 (see FIG8 ). As the ink cartridge 30 is further inserted into the cartridge attachment unit 110 in the insertion direction 51, the ink cartridge 30 is pressed against the second protrusion 86, causing the slider 107 to move in the insertion direction 51 against the biasing force of the tension spring 114. The slider 107 applies a biasing force to the ink cartridge 30 in the removal direction 52. The slider 107 and the tension spring 114 are examples of biasing members.

<Locking portion 145>

As shown in Figures 2 and 7, the locking portion 145 extends in the left direction 56 and the right direction 55 of the housing 101 near the top surface of the housing 101 and near the opening 112. The locking portion 145 is a rod-shaped member extending in the left direction 56 and the right direction 55. The locking portion 145 is, for example, a metal cylinder. The two ends of the locking portion 145 in the left direction 56 and the right direction 55 are fixed to the walls that define the two ends of the housing 101 in the left direction 56 and the right direction 55. Therefore, the locking portion 145 neither rotates relative to the housing 101 nor causes other relative motion. The locking portion 145 extends in the left direction 56 and the right direction 55 across four spaces that can accommodate four ink cartridges 30. In each space in which the ink cartridges 30 are accommodated, there is space around the locking portion 145. Therefore, the ink cartridge 30 can access the locking portion 145 in the upward direction 54 or the removal direction 52.

The locking portion 145 holds the ink cartridge 30 attached to the cartridge attachment unit 110 in an attached position. When the ink cartridge 30 is inserted into the cartridge attachment unit 110 and rotated to the attached orientation, the ink cartridge 30 engages the locking portion 145. The locking portion 145 holds the ink cartridge 30 in the cartridge attachment unit 110 against the force of the slider 107 pressing the ink cartridge 30 in the removal direction 52 and the force of the coil spring 78 provided in the ink cartridge 30 pressing the ink cartridge 30 in the removal direction.

As shown in Figures 2 and 7, four contacts 106 are provided on the top surface of the housing 101 near its rear surface. Although not shown in detail in these figures, the four contacts 106 are spaced apart from each other in the left direction 56 and the right direction 55. In the ink cartridge 30, the four contacts 106 are positioned corresponding to the four electrodes 65, which will be described later with reference to Figures 3A and 4A. Each contact 106 is formed of a conductive and elastic material; the contact 106 is deformable in the upward direction 54. Four groups of four contacts 106 are provided corresponding to the four ink cartridges 30 that can be accommodated in the housing 101. There is no limitation on the number of contacts 106 and the number of electrodes 65; any number of contacts 106 and any number of electrodes 65 can be used.

Each contact 106 is electrically connected to a computing unit with a circuit interposed therebetween. The computing unit includes, for example, a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM). The computing unit can be configured as a control unit for the printer 10. When the contact 106 and its corresponding electrode 65 are electrically connected to each other, a voltage Vc is applied to the electrode 65, the electrode 65 is grounded, or power is supplied to the electrode 65. Due to the electrical connection between the contact 106 and its corresponding electrode 65, data stored in an integrated circuit (IC) in the ink cartridge 30 can be accessed. The output from the circuit is input into the computing unit.

<Rod 125>

As shown in Figures 2 and 7, the rod 125 is provided on the rear surface of the housing 101 at a position above the ink needle 102. The rod 125 protrudes from the rear surface of the housing 101 in the removal direction 52. The cross-section of the rod 125 in a direction perpendicular to the removal direction 52 has an inverted U-shape similar to the upper half of a cylindrical shape. The rib protrudes upward from the highest position of the rod 125 in the removal direction 52. When the ink cartridge 30 is attached to the cartridge attachment unit 110, that is, when the ink cartridge 30 is in the attached position, the rod 125 is inserted into the recess 96 formed below the IC board 64 in the ink cartridge 30.

<Sensor 103>

As shown in Figures 2 and 7, the sensor 103 is arranged on the top surface of the housing 101. The sensor 103 has a light-emitting portion and a photosensitive portion. The light-emitting portion is set to the right of the photosensitive portion in the right direction 55, or is set to the left of the photosensitive portion in the left direction 56, with a space between the light-emitting portion and the photosensitive portion. After the attachment of the ink cartridge 30 to the box attachment unit 110 is completed, the optical access portion 62 provided in the ink cartridge 30 is located between the light-emitting portion and the photosensitive portion. In other words, the light-emitting portion and the photosensitive portion are oppositely arranged in a state where the optical access portion 62 is placed between the light-emitting portion and the photosensitive portion, wherein the optical access portion 62 is in the ink cartridge 30 inserted into the box attachment unit 110.

The sensor 103 outputs different detection signals depending on whether the light emitted by the light-emitting portion has been received by the light-receiving portion. For example, when the light-receiving portion cannot receive the light emitted by the light-emitting portion (i.e., the light-receiving intensity of the light-receiving portion is lower than a predetermined intensity), the sensor 103 outputs a low-level signal whose signal level is lower than a threshold level. When the light-receiving portion can receive the light emitted by the light-emitting portion (i.e., the light-receiving intensity of the light-receiving portion is equal to or higher than a predetermined intensity), the sensor 103 outputs a high-level signal whose signal level is equal to or higher than the threshold level.

The positioning member 108 extends above the guide 105 and below the rod 125 in the left direction 56 and the right direction 55 of the housing 101. The positioning member 108 protrudes from the rear surface of the housing 101 in the removal direction 52. The size of the positioning member 108 protruding from the rear surface of the housing 101 in the removal direction 52 is smaller than the size of the guide 105 protruding from the rear surface of the housing 101 in the removal direction 52. The upper surface 115 of the positioning member 108 contacts the lower surface 89 of the first protrusion 85 in the ink cartridge 30 attached to the cartridge attachment unit 110.

<Ink Cartridge 30>

The ink cartridge 30 shown in Figures 3A and 3B to 6 is a container for holding ink. The space formed in the ink cartridge 30 is a holding chamber (an example of a liquid holding chamber) 36. The holding chamber 36 is formed with an inner frame 35, which is placed in the rear cover 31 and front cover 32 that form the outer shape of the ink cartridge 30. The inner frame 35 is an example of a body. The rear cover 31, front cover 32, and inner frame 35 are examples of a housing.

The orientation of the ink cartridge 30 shown in Figures 3A and 3B to 6 and Figures 15A and 15B is the orientation taken when the ink cartridge 30 is in the attached orientation (first orientation). As described later, the ink cartridge 30 has a front 140, a rear 41, an upper surface 39 and 141, and a lower surface 42 and 142. In the orientation of the ink cartridge 30 shown in Figures 3A and 3B to 6, the direction extending from the rear surface 41 toward the front 140 matches the insertion direction 51 and the forward direction 57, the direction extending from the front 140 toward the rear surface 41 matches the removal direction 52, the direction extending from the upper surface 39 and 141 toward the lower surface 42 and 142 matches the downward direction 53, and the direction extending from the lower surface 42 and 142 toward the upper surface 39 and 141 matches the upward direction 54. When the ink cartridge 30 is attached to the cartridge attachment unit 110 , the front surface 140 faces the insertion direction 51 and the forward direction 57 , the rear surface 41 faces the removal direction 52 , the lower surfaces 42 and 142 face the downward direction 53 , and the upper surfaces 39 and 141 face the upward direction 54 .

As shown in Figures 3A and 3B to 6, the ink cartridge 30 is formed with a rear cover 31 having a generally rectangular parallelepiped shape, a front cover 32 including a front surface 140, and an inner frame 35 defining a holding chamber 36. The rear cover 31 and the front cover 32 are combined to form the outer shape of the ink cartridge 30. The inner frame 35 is placed inside the combined rear cover 31 and front cover 32. The ink cartridge 30 is generally flat; its dimensions in the right direction 55 and the left direction 56 are smaller, and its dimensions in the downward direction 53 and the upward direction 54, as well as in the forward direction 57 and the rearward direction 58 are larger than those in the right direction 55 and the left direction 56. The front surface 140 is the surface of the front cover 32 that faces the insertion direction 51 (forward direction 57) when the ink cartridge 30 is inserted into the cartridge attachment unit 110. The rear surface 41 is the surface of the rear cover 31 that faces the removal direction 52 (58) when the ink cartridge 30 is inserted into the cartridge attachment unit 110. That is, the rear surface 41 is disposed opposite to the front surface 140 of the front cover 32 with the holding chamber 36 interposed therebetween.

<Back cover 31>

As shown in Figures 3A and 3B and Figures 4A and 4B, the rear cover 31 is formed into a box body having side surfaces 37 and 38 spaced apart from each other in the right direction 55 and the left direction 56, an upper surface 39 facing the upward direction 54, and a lower surface 42 facing the downward direction 53, with the upper surface 39 and the lower surface 42 extending from the rear surface 41 in the insertion direction 51. The rear cover 31 has an opening facing the forward direction 57. The inner frame 35 is inserted into the rear cover 31 through the opening. That is, the rear cover 31 covers the rear portion of the inner frame 35. With the inner frame 35 inserted, the lower surface 42 is positioned opposite the upper surface 39, holding the chamber 36 therebetween.

The rear surface 41 has an upper portion 41U and a lower portion 41L. The upper portion 41U is located above the lower portion 41L in the upward direction 54. The lower portion 41L is located below the upper portion 41U in the downward direction 53. In other words, the lower portion 41L is located in the forward direction 57 from the upper portion 41U. The upper portion 41U and the lower portion 41L are both flat surfaces that intersect with each other, but they are not orthogonal to each other. The lower portion 41L is inclined relative to the downward direction 53 and the upward direction 54 so that as the lower portion 41L approaches the lower surface 42, the lower portion 41L approaches the front surface 140. In order to prompt the user to push the ink cartridge 30, as shown in Figure 15B, a sheet is pasted on the upper portion 41U to indicate PUSH or other character strings, symbols such as arrows, graphics indicating pressing with fingers, etc.

As shown in Figures 3A and 4A, a protrusion 43 is formed on the upper surface 39 of the rear cover 31. The protrusion 43 extends from the center of the upper surface 39 in the right direction 55 and the left direction 56 in the forward direction 57 and the rearward direction 58. The surface of the protrusion 43 facing the rearward direction 58 is a locking surface 151. The locking surface 151 extends in the downward direction 53 and the upward direction 54. When the ink cartridge 30 is attached to the cartridge attachment unit 110, the locking surface 151 can be brought into contact with the locking portion 145 in the removal direction 52. When the locking surface 151 is brought into contact with the locking portion 145 in the removal direction 52, the ink cartridge 30 is retained in the cartridge attachment unit 110 against the force of the tension spring 14 biasing the ink cartridge 30 through the slider 107 and the force of the coil spring 78 biasing the ink cartridge 30.

Reinforcement surface 152 extends across locking surface 151, continuing to the end of locking surface 151 in right direction 55. Reinforcement surface 153 extends across locking surface 151, continuing to the end of locking surface 151 in left direction 56. Reinforcement surface 152 extends in forward direction 57, forming an acute angle with respect to a virtual surface including locking surface 151, and extends in downward and upward directions 53, 54, and right direction 55. Reinforcement surface 153 extends in forward direction 57, forming an acute angle with respect to a virtual surface including locking surface 151 and extending in downward and upward directions 53, 54, and left direction 56. Reinforcement surfaces 152 and 153 increase the strength of protrusion 43, reducing the risk of damage to locking surface 151. Since reinforcement surfaces 152 and 153 do not extend beyond locking surface 151 in rearward direction 58, they do not contact locking portion 145. Therefore, even if the locking surface 151 slides on the locking portion 145 , the presence of the reinforcing surfaces 152 and 153 does not increase the sliding resistance.

On protrusion 43, horizontal surface 154 is provided so as to continue to locking surface 151 and extend from locking surface 151 in forward direction 57. Horizontal surface 154 extends in rightward and leftward directions 55, 56, and in forward and rearward directions 57, 58. Inclined surface 155 is provided so as to continue to horizontal surface 154 and extend from horizontal surface 154 in forward direction 57. Inclined surface 155 faces upward direction 54 and forward direction 57. Therefore, inclined surface 155 is visible when ink cartridge 30 is viewed in downward direction 53, and is also visible when ink cartridge 30 is viewed in rearward direction 58. Since locking surface 151 continues to inclined surface 155 via horizontal surface 154, the boundary between locking surface 151 and horizontal surface 154 does not become a pointed convex shape. During the insertion of the ink cartridge 30 into the cartridge attachment unit 110 , the locking portion 145 is smoothly guided by the inclined surface 155 and the horizontal surface 154 in the rearward direction 58 beyond the locking surface 151 while the locking portion 145 contacts the inclined surface 155 and the horizontal surface 154 .

Reinforcement surface 156 extends across locking surface 151, continuing to the end of inclined surface 155 in right direction 55. Reinforcement surface 157 extends across locking surface 151, continuing to the end of inclined surface 155 in left direction 56. Reinforcement surface 156 extends in downward direction 53, forming an acute angle with a virtual surface including inclined surface 155 and extending in right direction 55. Reinforcement surface 157 extends in downward direction 53, forming an acute angle with a virtual surface including inclined surface 155 and extending in left direction 56. Reinforcement surfaces 156 and 157 increase the strength of protrusion 43, thereby reducing the risk of damage to inclined surface 155. Since reinforcement surfaces 156 and 157 do not extend upward beyond inclined surface 155, they do not contact locking portion 145. Therefore, the presence of reinforcement surfaces 156 and 157 does not increase the sliding resistance of inclined surface 155 during sliding on locking portion 145.

A manipulation portion 90 is provided on the upper surface 39 of the rear cover 31, displaced from the locking surface 151 in the rearward direction 58. A secondary upper surface 91 is formed at the rear end of the upper surface 39 of the rear cover 31, below the rest of the upper surface 39 in the downward direction 53. The manipulation portion 90 is provided above the secondary upper surface 91, with a space therebetween. The manipulation portion 90 is shaped like a flat plate so that it protrudes beyond the protrusion 43 in the upward direction 54 from near the boundary between the secondary upper surface 91 and the rest of the upper surface 39, and then bends diagonally in the rearward direction 58 and the downward direction 53. A rib 94 is provided between the manipulation portion 90 and the secondary upper surface 91, extending therefrom and in the rearward direction 58. As shown in FIG. 15 , dimensions of the rib 94 in the right direction 55 and the left direction 56 are smaller than dimensions of the manipulation portion 90 and the sub-upper surface 91 in the right direction 55 and the left direction 56 .

The operating portion 90 has an operating surface 92 facing the upward direction 54 and the rearward direction 58. The operating surface 92 and the secondary upper surface 91 are arranged at the same position in the forward direction 57 and the rearward direction 58. In other words, when the ink cartridge 30 is viewed from the downward direction 53, the operating surface 92 and the secondary upper surface 91 are arranged at the same position. The operating surface 92 has a plurality of protrusions, such as a plurality of ridges 93 extending in the right direction 55 and the left direction 56, and spaced apart from each other in the forward direction 57 and the rearward direction 58. Due to the ridges 93 functioning as a plurality of protrusions, the user can easily identify the operating surface 92. In addition, when the user operates the operating surface 92 with a finger, the finger does not easily slip on the operating surface 92.

As shown in FIG15 , the manipulation surface 92 is visible when the ink cartridge 30 is viewed in the downward direction 53, and is also visible when the ink cartridge 30 is viewed in the forward direction 57. In other words, the manipulation surface 92 is visible when the ink cartridge 30 is viewed from the upper surface 39 toward the lower surface 42, and is also visible when the ink cartridge 30 is viewed from the rear surface 41 toward the front surface 140. When a user removes the ink cartridge 30 attached to the cartridge attachment unit 110, the user manipulates the manipulation surface 92. The manipulation portion 90 is fixed to the rear cover 31, for example, by being molded together with the rear cover 31. Therefore, the manipulation portion 90 does not rotate relative to the rear cover 31 or cause other relative movement. Therefore, the force applied by the user to the manipulation surface 92 is transmitted intact to the rear cover 31 without changing direction. In this embodiment, the manipulation portion 90 does not rotate relative to the inner frame 35 and the retaining chamber 36, nor does it cause other relative movement.

<Front cover 32>

As shown in Figures 3A and 3B and Figures 4A and 4B, the front cover 32 is formed as a box body having side surfaces 143 and 144 extending from the front surface 140 in the rearward direction 58 and spaced apart from each other in the right direction 55 and the left direction 56, and also having an upper surface 141 and a lower surface 142. The side surfaces 143 and 144 extend from the front surface 140 in the rearward direction 58 and are spaced apart from each other in the downward direction 53 and the upward direction 54. The front cover 32 has an opening facing the rearward direction 58. The inner frame 35 is inserted into the front cover 32 through the opening. In other words, the front cover 32 covers the front portion of the inner frame 35 that is not covered by the rear cover 31.

When the rear cover 31 and the front cover 32 are combined, that is, when the ink cartridge 30 is assembled, the upper surface 141 of the front cover 32, together with the upper surface 39 of the rear cover 31, forms the upper surface of the ink cartridge 30, and the lower surface 142 of the front cover 32, together with the lower surface 42 of the rear cover 31, forms the lower surface of the ink cartridge 30. Specifically, when the ink cartridge 30 is placed in the attached orientation (first orientation), the lower surface 142 of the front cover 32 extends in the forward direction 57 and the rearward direction 58, and the lower surface 42 of the rear cover 31 is inclined in the downward direction 53 and the rearward direction 58. The side surfaces 143 and 144 of the front cover 32, together with the side surfaces 37 and 38 of the rear cover 31, form the side surfaces of the ink cartridge 30. In the assembled state of the ink cartridge 30, the front surface 140 of the front cover 32 (the front surface 140 forms the front surface of the ink cartridge 30) and the rear surface 41 of the rear cover 31 (the rear surface 41 forms the rear surface of the ink cartridge 30) are spaced apart from each other in the forward direction 57 and the rearward direction 58. Each of the front surface, rear surface, upper surface, lower surface, and side surfaces of the ink cartridge 30 is not necessarily a single plane. That is, the front surface is a surface visible when the ink cartridge 30 is viewed in the rearward direction 58 when placed in the first orientation, and the front surface is positioned so as to be displaced in the forward direction 57 from the center of the ink cartridge 30 when placed in the first orientation; the rear surface is a surface visible when the ink cartridge 30 is viewed in the forward direction 57 when placed in the first orientation, and the rear surface is displaced in the rearward direction 58 from the center of the ink cartridge 30 when placed in the first orientation; the upper surface is a surface visible when the ink cartridge 30 is viewed in the downward direction 53 when placed in the first orientation, and the upper surface is displaced in the upward direction 54 from the center of the ink cartridge 30 when placed in the first orientation; the lower surface is a surface visible when the ink cartridge 30 is viewed in the upward direction 54 when placed in the first orientation, and the lower surface is displaced in the downward direction 53 from the center of the ink cartridge 30 when placed in the first orientation. The same is true for the side surfaces. That is, although in this embodiment, the upper surface 39 as part of the rear cover 31 is located above the upper surface 141 as part of the front cover 32, it is not limited to this, and the upper surfaces 141 and 39 can be at the same position in the downward direction 53 and the upward direction 54.

A recess 96 is formed in the upper portion of the front surface 140 of the front cover 32, recessed in the rearward direction 58. By attaching the ink cartridge 30 to the cartridge attachment unit 110, the rod 125 enters the recess 96. Therefore, the cross-section of the recess 96, in a direction perpendicular to the forward and rearward directions 57 and 58, has a shape corresponding to the cross-sectional shape of the rod 125. The recess 96 extends from the front surface 140 in the rearward direction 58. Two recesses 99, recessed in the downward direction 53 from the upper surface 141, are displaced in the rearward direction 58 from the IC board 64. One of the recesses 99 extends from the IC board 64 in the rightward direction 55, and the other extends from the IC board 64 in the leftward direction 56. By attaching the ink cartridge 30 to the cartridge attachment unit 110, the rod 125 enters the space defined by the recess 96.

A hole 97 is formed in the lower portion of the front surface 140 of the front cover 32, which passes through the front cover 32 in the rearward direction 58. When the inner frame 35 is inserted into the front cover 32, the hole 97 is a hole through which the ink supply portion 34 in the inner frame 35 is exposed to the outside. Therefore, the hole 97 is formed to correspond to the position, size, and shape of the ink supply portion 34 in the inner frame 35.

A first protrusion 85 and a second protrusion 86 are formed on the front surface 140 of the front cover 32. The first protrusion 85 protrudes from the upper end of the front cover 32 in the forward direction 57. A recess 96 is formed at the end of the first protrusion 85. The end of the first protrusion 85 forms a portion of the front surface 140. The lower surface 89 of the first protrusion 85 is located between the IC board 64 and the ink supply portion 34 in the downward direction 53 and the upward direction 54. When the ink cartridge 30 is attached to the cartridge attachment unit 110, the lower surface 89 contacts the upper surface 115 of the positioning member 108 in the cartridge attachment unit 110. The lower surface 89 is equivalent to the positioning surface.

The second protrusion 86 protrudes from the front surface 140 in the forward direction 57 at the lower end of the front surface 140 of the front cover 32, that is, protrudes below the ink supply portion 34. A recess 87 that opens in the forward direction 57 and the downward direction 53 is formed in the lower surface of the second protrusion 86. A portion of the recess 87 protrudes from the lower surface 142 of the front cover 32 in the downward direction 53. During the process of inserting the ink cartridge 30 into the cartridge attachment unit 110, the slider 107 enters the recess 87 of the second protrusion 86 and contacts it.

A hole 98 (an example of an opening) that passes through the front cover 32 in the downward direction 53 is formed in the upper surface 141 of the front cover 32. When the inner frame 35 is inserted into the front cover 32, the hole 98 is a hole through which the light receiving portion 62 in the inner frame 35 is exposed to the outside. Therefore, the hole 98 is formed to correspond to the position, size, and shape of the light receiving portion 62 in the inner frame 35.

Although in this embodiment, an opening (hole 98) is formed in the front cover 32 so as to expose the light receiving portion 62 in the inner frame 35 from the upper surface 141, the opening through which the light receiving portion 62 is exposed may be formed in only one of the front cover 32 and the rear cover 31, or may be formed in both the front cover 32 and the rear cover 31. Although in this embodiment, the hole 98 is formed so that the portion behind the light receiving portion 62 is covered by the rear cover 31, the hole 98 may be formed so that the entire light receiving portion 62 is exposed.

The IC board 64 is provided on the upper surface 141 of the front cover 32 and above the first protrusion 85, that is, above the ink supply portion 34. The IC board 64 is electrically connected to four contacts 106 (see FIG. 2 ) aligned in the right direction 55 and the left direction 56 at the center of the ink cartridge 30 attached to the cartridge attachment unit 110. When the ink cartridge 30 is attached to the cartridge attachment unit 110, the IC board 64 is electrically connected to the contacts 106. The dimension of the circuit board 64 in the first direction 51 is smaller than the dimensions of the circuit board 64 in the left direction 56 and the right direction 55.

On the IC board 64, an IC (not shown in each figure) and four electrodes 65 are mounted. The four electrodes 65 are aligned in the right direction 55 and the left direction 56. The IC, which is a semiconductor integrated circuit, stores information about the ink cartridge 30, such as the lot number, manufacturing date and time, and data indicating the ink color and other information, in such a manner that the information can be read.

Electrodes 65 are electrically connected to the IC. Each electrode 65 extends in the forward direction 57 and the rearward direction 58. The four electrodes 65 are spaced apart from each other in the right direction 55 and the left direction 56. Each electrode 65 is exposed on the upper surface of the IC board 64 so as to be connected. Electrodes 65 are an example of an electrical interface.

<Inner frame 35>

Although not shown in each drawing, the inner frame 35 is annularly configured with a pair of end surfaces that are open in the right direction 55 and the left direction 56. The pair of open end surfaces of the inner frame 35 are sealed with a film (not shown), forming a holding chamber 36 in which ink can be held. When the inner frame 35 is inserted into the front cover 32, the front surface 40 defining the holding chamber 36 faces the rear surface of the front surface 140 of the front cover 32. The ink supply portion 34 (an example of a liquid outflow unit) is provided below the front surface 40.

<Ink Supply Unit 34>

6 , the ink supply portion 34 is provided at a lower portion of the front surface 140 so as to protrude beyond the front surface 40 of the inner frame 35 in the forward direction 57. The ink supply portion 34 has a cylindrical outer shape and protrudes outward through a hole 97 formed in the front surface 140 of the front cover 32. The ink supply portion 34 has a cylindrical wall 73 in a cylindrical shape having an internal space and also has a sealing member 76 and a cap 79 attached to the cylindrical wall 73.

The cylindrical wall 73 extends from the interior to the exterior of the holding chamber 36. The end of the cylindrical wall 73 in the removal direction 52 opens into the holding chamber 36. The end of the cylindrical wall 73 in the insertion direction 51 opens to the exterior of the ink cartridge 30. Therefore, the cylindrical wall 73 communicates with the holding chamber 36 and the exterior of the ink cartridge 30 through the interior space. That is, the ink supply portion 34 supplies the ink held in the holding chamber 36 to the exterior of the ink cartridge 30 through the interior space of the cylindrical wall 73. A sealing member 76 and a cap 79 are attached to the end of the cylindrical wall 73 in the insertion direction 51.

The valve body 77 and the coil spring 78 are housed in the interior space of the cylindrical wall 73. The valve body 77 and the coil spring 78 serve to selectively switch the state of the ink supply portion 34 between a state in which ink flows from the holding chamber 36 through the interior space of the cylindrical wall 73 to the outside of the ink cartridge 30 (see FIG. 11 ) and a state in which ink does not flow from the holding chamber 36 through the interior space of the cylindrical wall 73 to the outside of the ink cartridge 30 (see FIG. 6 ).

When valve body 77 moves in forward direction 57 and rearward direction 58, ink supply opening 71, which is a through hole formed at the center of sealing member 76, is opened and closed. Coil spring 78 biases valve body 77 in forward direction 57. Therefore, valve body 77 closes ink supply opening 71 in sealing member 76 in a state where no external force is applied.

A sealing member 76 is provided at the end of the cylindrical wall 73. The sealing member 76 is a disc-shaped member with a through hole at its center. The sealing member 76 is made of an elastic material, such as rubber or an elastomer. The through hole extending in the center of the sealing member 76 in the forward and rearward directions 57 and 58 forms the inner surface of the cylinder, thereby forming the ink supply opening 71. The inner diameter of the ink supply opening 71 is slightly smaller than the outer diameter of the ink needle 102. Since the cap 79 is mounted on the outside of the cylindrical wall 73, the sealing member 76 contacts the end of the cylindrical wall 73 in a liquid-tight manner.

When the ink cartridge 30 is inserted into the cartridge attachment unit 110 with the valve body 77 closing the ink supply opening 71, the ink needle 102 enters the ink supply opening 71. The outer circumferential surface of the ink needle 102 contacts the inner circumferential surface defining the ink supply opening 71 in a liquid-tight manner, while the ink needle 102 elastically deforms the sealing member 76. When the end of the ink needle 102 passes through the sealing member 76 and enters the interior space of the cylindrical wall 73, the end contacts the valve body 77. As the ink cartridge 30 is further inserted into the cartridge attachment unit 110, the ink needle 102 moves the valve body 77 in the rearward direction 58 against the biasing force of the coil spring 78. This allows the ink held in the retaining chamber 36 to flow through the interior space of the cylindrical wall 73 to the end of the ink needle 102. Although not shown in each figure, ink flows from the interior space of the cylindrical wall 73 into the interior space of the ink needle 102 through a through-hole formed in the end of the ink needle 102. Thus, the ink held in the holding chamber 36 can flow out to the outside through the internal space of the cylindrical wall 73 and the ink needle 102 .

The valve body 77 that closes the ink supply opening 71 is not necessarily provided in the ink supply portion 34. For example, the ink supply opening 71 may be blocked by a film or the like. In this case, when the ink cartridge 30 is inserted into the cartridge attachment unit 110, the ink needle 102 breaks the film, and the end of the ink needle 102 thereby passes through the ink supply opening 71 and enters the internal space of the cylindrical wall 73. Alternatively, the ink supply opening 71 may be closed due to the elasticity of the sealing member 76. In this case, the ink supply opening 71 is expanded by being pressed by the ink needle 102 only when the ink needle 102 is inserted.

<Liquid Level Detection Unit 60>

As shown in Figure 6, the ink cartridge 30 has a liquid level detection portion 60 (an example of a liquid detection portion). The liquid level detection portion 60 has a light receiving portion 62 and a sensor arm 59 (an example of a light attenuating portion). The inner frame 35 has a light receiving portion 62 extending from the upper surface in the upward direction 54. The light receiving portion 62 is a protrusion that defines its continuation into the internal space of the holding chamber 36. The light receiving portion 62 is translucent, allowing light to pass through the light receiving portion 62 in the right direction 55 and the left direction 56. In other words, the light receiving portion 62 is configured to be received by light traveling from the light emitting portion in the sensor 103 of the printer 10 toward the photosensitive portion. Specifically, the light receiving portion 62 has side surfaces 66 and 67 (examples of a first side surface and a second side surface) that extend in the downward direction 53 and the upward direction 54, as well as the forward direction 57 and the rearward direction 58. Light propagating in the direction in which the side surfaces 66 and 67 separate, that is, in the right direction 55 and the left direction 56, passes through the light receiving portion 62. The distance between side surfaces 66 and 67 in the right direction 55 and the left direction 56 is smaller than the dimensions of side surfaces 66 and 67. The dimensions of side surfaces 66 and 67 in the upward direction 54 are smaller than the distance between side surfaces 66 and 67 in the right direction 55 and the left direction 56. The optical receiving portion 62 is exposed to the outside through the hole 98 in the front cover 32. The side surfaces 66 and 67 extend above the upper surface 141 in the upward direction 54 through the hole 98 in the front cover 32. Therefore, the side surfaces 66 and 67 intersect with the upper surface 141.

6 , a sensor arm 59 (an example of a light attenuating portion) is provided in the holding chamber 36 in the inner frame 35. The sensor arm 59 is supported by a rotation shaft 61 extending in the right direction 55 and the left direction 56 and is rotatable about the rotation shaft 61.

The sensor arm 59 has a float 63. The float 63 has a smaller specific gravity than the ink held in the holding chamber 36. Therefore, in the holding chamber 36, while the float 63 is in the ink, the float 63 generates buoyancy. When the holding chamber 36 is substantially completely filled with ink, the sensor arm 59 rotates counterclockwise in FIG. 6 due to the buoyancy of the float 63. The portion 68 of the sensor arm 59 has entered the interior of the light receiving portion 62. When the portion 68 of the sensor arm 59 contacts the wall defining the end of the light receiving portion 62 in the forward direction 57, the orientation of the sensor arm 59 is maintained. While in this state (an example of the first state), the ink detection portion 60 changes the state of the light transmitted from the emitter to the photosensitive portion. More specifically, the portion 68 of the sensor arm 59 blocks light emitted from the sensor 103 and that would otherwise propagate through the light receiving portion 62 in the right direction 55 or the left direction 56, and performs other processing on the light.

Specifically, when light emitted from the light-emitting portion of the sensor 103 reaches one of the right and left surfaces of the light receiving portion 62, the portion 68 of the sensor arm 59 reduces the intensity of the light, which is intended to be emitted from the other of the right and left surfaces of the light receiving portion 62 and reach the light-sensing portion, to below a predetermined intensity (at which light is transmitted), for example, to zero. The portion 68 of the sensor arm 59 may completely cut off the light so that it does not propagate in the right direction 55 or the left direction 56, partially absorb the light, attenuate the light, bend the direction in which the light propagates, or totally reflect the light to change the state of the light transmitted from the emitter to the light-sensing portion.

When the ink in the holding chamber 36 decreases and the ink level drops below the position of the float 63, the portion 68 of the sensor arm 59 is in an orientation such that the portion 68 blocks light that would otherwise propagate through the optical receiving section 62 and performs other processing on the light. The float 63 then descends along with the ink level. Consequently, the sensor arm 59 rotates counterclockwise in FIG. 6 . Due to the clockwise rotation, the portion 68 of the sensor arm 59 (which has already entered the interior of the optical receiving section 62) moves substantially in the rearward direction 58 through the interior space of the optical receiving section 62 and reaches the end of the interior space of the optical receiving section 62 in the rearward direction 58, causing the portion 68 to deviate from the optical path extending from the light-emitting section to the light-receiving section of the sensor 103. In this state (an example of the second state), in this embodiment, it is expected that light propagating from one of the right and left surfaces of the optical receiving section 62 to the other can pass through the interior space of the optical receiving section 62, and the intensity of the light reaching the photosensitive section of the sensor 103 is equal to or higher than the predetermined intensity (at which light is transmitted).

<Intervention Wall 80>

As shown in Figures 3A and 4A , an intervening wall (an example of a second light attenuating portion) 80 is provided on the upper surface 141 of the front cover 32; the intervening wall 80 is displaced from the IC board 64 in the rearward direction 58 and from the hole 98 in the forward direction 57. The intervening wall 80 protrudes from the upper surface 141 in the upward direction 54. The intervening wall 80 has a front surface 81 and a rear surface 82 that extend in the right and left directions 55 and 56, side surfaces 83 and 84 that extend in the forward and rearward directions 57 and 58, and an upper surface 88. The dimension D1 (see Figure 5 ) of the side surfaces 83 and 84 in the forward and rearward directions 57 and 58 is greater than the dimension D2 (see Figure 15A ) of the front and rear surfaces 81 and 82 in the right and left directions 55 and 56. In other words, the intervening wall 80 has a thin plate shape, with the dimensions in the forward and rearward directions 57 and 58 being greater than the dimensions in the right and left directions 55 and 56. In this embodiment, when the ink cartridge 30 is attached to the cartridge attachment unit 110, light emitted from the light-emitting portion of the sensor reaches one of the side surfaces 83 and 84 of the intervening wall 80. The side surfaces 83 and 84 reduce the intensity of light that is expected to be emitted from the other of the side surfaces of the intervening wall 80 and reach the photosensitive portion to below a predetermined intensity (at which light is transmitted), for example, to zero. In other words, the insertion of the ink cartridge 30 into the cartridge attachment unit is detected by the intervening wall 80, which is configured to cut off or attenuate the light from the emitter toward the photosensitive portion.

<Placement of the Optical Inlet Portion 62, IC Board 64, Intervention Wall 80, Locking Surface 151, etc. in the Ink Cartridge 30>

As shown in Figures 3A and 3B to Figures 6 and 15A, the IC board 64 is arranged to be displaced from the optical receiving portion 62 in the insertion direction 51 (forward direction 57). On the upper surface 141 of the front cover 32, the IC board 64 is arranged to be closer to the side surface 143 located in the right direction 55 than to the side surface 144 located in the left direction 56. The center of the IC board 64 is arranged to be closer to the side surface 66 of the optical receiving portion 62 in the left direction 56 than to the side surface 67 of the optical receiving portion 62. The light emitting portion of the sensor 103 faces the side surface 67, and the light sensing portion in the sensor 103 faces the side surface 66. When viewed in the downward direction 53 and the upward direction 54, the IC board 64 is arranged in the same position as the ink supply portion 34. In other words, at least a portion of the IC board 64 overlaps with the ink supply portion 34 in the downward direction 53 and the upward direction 54.

The intervening wall 80 is provided above the IC board 64 in the upward direction 54. In the rearward direction 58, the intervening wall 80 is provided closer to the light receiving portion 62 than the IC board 64 is to the light receiving portion 62. The intervening wall 80 extends upward beyond the upper end of the sensor arm 59, which contacts the wall defining the end of the light receiving portion 62 in the forward direction 57.

The dimensions of the rear surface 82 of the intervention wall 80 in the right and left directions are longer than the distance between the side surface 66 and the side surface 67 of the light receiving portion 62 .

The optical access portion 62 is displaced from the IC board 64 in the removal direction 52 (displaced from the IC board 64 in the rearward direction 58). The optical access portion 62 is arranged above the IC board 64 in the downward direction 53 and the upward direction 54. In other words, the internal space of the liquid level detection portion is arranged above the electrode 65 of the IC board 64. Specifically, the IC board 64 is displaced from the liquid outlet portion 34 in the upward direction 54 by a first distance, and the optical access portion 62 is displaced from the liquid outlet portion 34 in the upward direction 54 by a second distance that is greater than the first distance. In more detail, when the ink cartridge 30 is attached to the cartridge attachment unit 110, the area of the optical access portion 62 through which the light from the light emitting portion passes in the right direction 55 and the left direction 56 is located above the electrode 65 of the IC board. The locking surface 151 is displaced from the optical access portion 62 in the removal direction 52 (displaced from the optical access portion 62 in the rearward direction 58). In the upward direction 54, the light receiving portion 62 is disposed closer to the locking surface 151 than the IC board 64 is to the locking surface 151. The upper end of the light receiving portion 62 in the upward direction 54 is closer to the locking surface 151 than the IC board 64 is to the locking surface 151. That is, in the upward direction 54, the upper end of the locking surface 151, the upper end of the light receiving portion 62, and the upper surface of the IC board 64 are disposed at higher positions in this order.

The dimensions of the locking surface 151 in this embodiment in the downward direction 53 and the upward direction 54 are smaller than the dimensions of the optical receiving portion 62 in the downward direction 53 and the upward direction 54. However, since the upper surface 39 of the rear cover 31 is located above the upper surface 141 of the front cover 32, the upper end of the locking surface 151 is located above the upper surface of the optical receiving portion 62. Therefore, if the upper surface 39 of the rear cover 31 and the upper surface 141 of the front cover 32 are set at the same position in the downward direction 53 and the upward direction 54, when the dimensions of the locking surface 151 in the downward direction 53 and the upward direction 54 are made larger than the dimensions of the optical receiving portion 62 in the downward direction 53 and the upward direction 54, the upper end of the locking surface 151 is located above the upper end of the optical receiving portion 62.

Lower surface 89 is located above ink supply portion 34 in upward direction 54 and below IC board 64 in downward direction 53 .

<Operation of Attaching Ink Cartridge 30 to Cartridge Attachment Unit 110>

Next, a process of attaching the ink cartridge 30 to the cartridge attachment unit 110 will be described.

7 , in the ink cartridge 30 to which the cartridge attachment unit 110 is yet to be attached, the valve body 77 closes the ink supply opening 71 in the sealing member 76 . This blocks the flow of ink from the holding chamber 36 to the outside of the ink cartridge 30 .

As shown in FIG7 , the ink cartridge 30 is inserted into the housing 101 through the opening 112 in the cartridge attachment unit 110. The upper portion 41U of the rear surface 41 of the rear cover 31 is positioned relative to the lower portion 41L in the removal direction 52, i.e., closer to the user, so the user inserts the ink cartridge 30 into the cartridge attachment unit 110 in the insertion direction 51 while pressing the upper portion 41U. As described above, since the sheet affixed to the upper portion 41U indicates "PUSH" or other character strings, symbols such as arrows, or graphics indicating pushing with a finger, the user is prompted to push the upper portion 41U. The lower portion of the ink cartridge 30, i.e., the lower portions of the front cover 32 and rear cover 31, enters the lower guide groove 109 in the housing 101. A second protrusion 86 is provided on the lower portion of the front cover 32. When a portion of the recess 87 protruding in the downward direction 53 from the lower surface 142 of the front cover 32 contacts the lower surface of the guide groove 109, the front portion of the front cover 32 is lifted, and the lower surface 142 is tilted with respect to the insertion direction 51. That is, on the lower surface of the guide groove 109, a portion of the recess 87 in the front cover 32 and a portion of the lower surface 142 near the lower end are brought into contact with each other.

As shown in FIG8 , as the ink cartridge 30 is further inserted into the cartridge attachment unit 110 in the insertion direction 51, the recess 87 in the second protrusion 86 in the front cover 32 comes into contact with the slider 107. At this point, the user pushes on the upper portion 41U of the rear surface 41 of the rear cover 31 of the ink cartridge 30. This causes the ink cartridge 30 to rotate counterclockwise in FIG8 , centered around the contact between the slider 107 and the recess 87 in the second protrusion 86. Due to this rotation, the lower surface 142 of the front cover 32 moves away from the lower surface of the lower guide groove 109, and the upper portion of the ink cartridge 30 comes into contact with the upper guide groove 109.

9 , when the ink cartridge 30 is inserted further in the insertion direction 51 against the biasing force of the tension spring 114 that biases the slider 107 in the removal direction 52, the cap 79 in the ink supply portion 34 begins to enter the guide 105. The recess 96 in the front cover 32 faces the rod 125, and the rod 125 begins to enter the recess 96. The upper surface 115 of the positioning member 108 in the cartridge attachment unit 110 begins to enter the space between the first protrusion 85 on the ink cartridge 30 and the ink supply portion 34.

10 , when the ink cartridge 30 is further inserted in the insertion direction 51 against the biasing force of the tension spring 114 that biases the slider 107 in the removal direction 52, the cap 7 in the ink supply portion 34 enters the guide 105 and the ink needle 102 enters the ink supply opening 71, causing the valve body 77 to move away from the sealing member 76 against the biasing force of the coil spring 78. In addition to the biasing force of the tension spring 114 applied by the slider 107, the biasing force of the coil spring 78 is applied to the ink cartridge 30 in the removal direction 52.

The upper surface 115 of the positioning member 108 in the cartridge attachment unit 110 contacts the lower surface 89 of the first protrusion 85 on the front cover 32, supporting the front cover 32 from below. When the IC board 64 reaches the portion below the contacts 106, the contacts 106 elastically deform upward, and the electrodes 65 are thereby electrically connected to their corresponding contacts 106. At this time, although the IC board 64 is biased in the downward direction 53 due to the elastic deformation of the contacts 106, the upper surface 115 of the positioning member 108 still supports the front cover 32 from below, so that the IC board 64 is accurately positioned relative to the contacts 106 in both the downward direction 53 and the upward direction 54. When the ink cartridge 30 is attached to the cartridge attachment unit 110, when the ink cartridge 30 is inserted in the insertion direction 51 and the contacts 106 are electrically connected to their corresponding electrodes 65, the contacts 106 slide on their corresponding electrodes 65. As the contacts 106 slide on their corresponding electrodes 65, shavings may be generated from the electrodes 65.

The protrusion 43 on the rear cover 31 reaches the locking portion 145, and the inclined surface 155 slides on the locking portion 145. When the user presses the upper portion 41U of the rear surface 41 in the insertion direction 51, a rotational torque is applied to the ink cartridge 30 in the counterclockwise direction in Figure 10. However, due to the contact between the inclined surface 155 and the locking portion 145, the ink cartridge 30 rotates counterclockwise in Figure 10, centered around the center of the ink supply opening 71 in the sealing member 76 into which the ink needle 102 has been inserted, against this rotational torque. In other words, centered around the center of the portion of the ink needle 102 that is in contact with the inner peripheral surface of the sealing member 76, which defines the ink supply opening 71. The orientation of the ink cartridge 30 shown in Figure 10 is referred to as the second orientation.

When the ink cartridge 30 is in the second orientation, the locking surface 151 of the protrusion 43 is located below the locking portion 145. When the ink cartridge 30 is in the second orientation, the above-mentioned rotation center and the IC board 64 are in the same position in the insertion direction 51. Therefore, the biasing force applied to the IC board 64 by the contact member 106 cannot act as a moment to rotate the ink cartridge 30 or is only a very small moment. When the ink cartridge 30 is in the second orientation, the lower surface 42 of the front cover 32 is in contact with or close to the lower surface of the lower guide groove 109, so that in this embodiment, the lower surface 42 of the front cover 32 is horizontal. When the ink cartridge 30 is in the second orientation, the lower portion 41L of the rear surface 41 of the rear cover 31 extends from the upper portion 41U in the insertion direction 51.

As shown in FIG11 , when the ink cartridge 30 is further inserted in the insertion direction 51 against the biasing force of the tension spring 114 and the coil spring 78, which bias the slider 107 in the removal direction 52, the inclined surface 155 and horizontal surface 154 of the protrusion 43 on the rear cover 31 are positioned closer to the rear surface of the housing 101 than to the locking portion 145. Because the upper portion 41U of the rear surface 41 is pressed by the user in the insertion direction 51, a rotational torque is applied to the ink cartridge 30 in the counterclockwise direction in FIG11 . As a result, the inclined surface 155 and horizontal surface 154 disengage from the locking portion 145. Consequently, the ink cartridge 30 rotates counterclockwise in FIG11 about the center of the ink supply opening 71 in the sealing member 76, into which the ink needle 102 has been inserted. The orientation of the ink cartridge 30 shown in FIG11 is referred to as the first orientation.

While the ink cartridge 30 is in the first orientation, the locking surface 151 faces the locking portion 145 in the removal direction 52. When the ink cartridge 30 is rotated from the second orientation to the first orientation, the rear cover 31 contacts the locking portion 145. Due to the vibration generated by this contact, the user recognizes that the ink cartridge 30 has been pressed in the insertion direction 51. If the user cancels the pressing of the ink cartridge 30 in the insertion direction 51, the ink cartridge 30 moves in the removal direction 52 due to the biasing force of the coil spring 78 and the biasing force of the tension spring 114 applied via the slider 107. When the ink cartridge 30 is placed in the first orientation, the locking surface 151 faces the locking portion 145 in the removal direction 52. Therefore, when the ink cartridge 30 moves slightly in the removal direction 52, the locking surface 151 contacts the locking portion 145. Therefore, the ink cartridge 30 remains in the first orientation, and movement in the removal direction 52 is restricted. That is, the ink cartridge 30 is in a state where the ink cartridge 30 has been positioned in the cartridge attachment unit 110 and has been completely attached to the cartridge attachment unit 110 .

In this embodiment, the IC board 64 is disposed on the upper surface 141 of the front cover 32, i.e., above the ink supply opening 71. Therefore, even if the ink in the holding chamber 36 flows out of the ink supply opening 71 when the ink cartridge 30 is inserted into or removed from the cartridge attachment unit 110, the ink that has flowed out is less likely to adhere to the IC board 64. While the ink cartridge 30 is attached to the cartridge attachment unit 110, the holding chamber 36 in the ink cartridge 30 is preferably open to the atmosphere. As an example of a structure that allows the holding chamber 36 to be open to the atmosphere, after the ink needle 102 has been inserted into the ink supply opening 71, as the ink supply valve 70 moves, the air path formed in the ink cartridge 30 can be connected to the outside, that is, can be opened to the outside. Alternatively, the air path formed in the ink cartridge 30 can be sealed with, for example, tape to isolate it from the atmosphere. The user can then remove the tape before attaching the ink cartridge 30 to the cartridge attachment unit 110 to allow the holding chamber 36 to be open to the atmosphere through the air path.

The operation of rotating the ink cartridge 30 from the second orientation to the first orientation in the cartridge attachment unit 110 will be described in more detail below.

As shown in FIG12 , the gravity applied to the ink cartridge 30 will be represented as G; the biasing force of the tension spring 114 and the biasing force of the coil spring 78 that bias the ink cartridge 30 placed in the first orientation in the removal direction 52 will be represented as F; the distance between the center of gravity M of the ink cartridge 30 placed in the second orientation and the rotation center O in the insertion direction 51 will be represented as L; and the distance from the lower end of the upper portion 41U of the rear surface 41 of the rear cover 31 of the ink cartridge 30 placed in the second orientation to a plane extending from the rotation center O in the upward direction 54 orthogonal to the insertion direction 51 will be defined as the height H. Then, the following equation holds true.

(Bias force F) × (height H) > (gravity G) × (distance L)

In the above equation, the product of the gravity G and the distance L is equal to the magnitude of the moment that rotates the ink cartridge 30 in the clockwise direction in FIG. 12 .

When the user inserts the ink cartridge 30 into the cartridge attachment unit 110 in the insertion direction 51, the user needs to press the ink cartridge 30 in the insertion direction 51 with a force greater than at least the biasing force F. That is, if the force with which the user presses the ink cartridge 30 in the insertion direction 51 is represented as U, the force U needs to be greater than the biasing force F. When the user holds the ink cartridge 30 in a specific position in the insertion direction 51 against the biasing force F, the biasing force F is equal to the force U. Therefore, when the user inserts the ink cartridge 30 into the cartridge attachment unit 110, a force U equivalent to at least the biasing force F is applied to the ink cartridge 30 in the insertion direction 51. The user presses the upper portion 41U of the rear surface 41 of the rear cover 31 of the ink cartridge 30, that is, the portion of the upper portion 41U located above its lower end. It will be assumed here that the upper portion 41U of the rear surface 41 is substantially orthogonal to the insertion direction 51 when the ink cartridge 30 is placed in the second orientation. Then, a moment at least equal to the product of the biasing force F and the height H is applied to the ink cartridge 30 in the counterclockwise direction in FIG. 12 . Since the above equation holds true, a moment in the counterclockwise direction in FIG. 12 exists in the ink cartridge 30 during insertion of the ink cartridge 30 into the cartridge attachment unit 110 in the insertion direction 51. Since the ink cartridge 30 receives the biasing force of the tension spring 114 at the second protrusion 86 via the slider 107, i.e., receives the biasing force of the tension spring 114 at a position below the rotation center O, the biasing force of the tension spring 114 also acts as a moment that rotates the ink cartridge 30 counterclockwise. Even without the biasing force of the tension spring 114, it can be understood that a counterclockwise moment is applied to the ink cartridge 30 when the ink cartridge 30 is inserted into the cartridge attachment unit 110.

Therefore, as described above, when the inclined surface 155 of the protrusion 43 slides on the locking portion 145 and the inclined surface 155 and the horizontal surface 154 move away from the locking portion 145 in the insertion direction 51, the ink cartridge 30 changes from the second orientation to the first orientation due to the moment in the counterclockwise direction in Figure 12.

As shown in Figure 14, when the ink cartridge 30 is in the first orientation, the upper end of the locking surface 151 is positioned outward beyond the virtual arc C, the center of which is the rotation center O, and the virtual arc C passes through the locking portion 145. The lower end of the locking surface 151 is located inside the virtual arc C. When the ink cartridge 30 is placed in the first orientation, the lower end of the locking surface 151 is further inward in the virtual arc C, that is, the lower end of the locking surface 151 is closer to the rotation center O than the upper end of the locking surface 151. Therefore, due to the biasing force applied in the removal direction 52, the locking portion 145 slides toward the lower end of the locking surface 151. As a result, with the locking portion 145 and the locking surface 151 in contact with each other, the ink cartridge 30 is rotated to be placed in the first orientation.

It will be assumed that during the insertion of the ink cartridge 30 into the cartridge attachment unit 110, the user pushes the lower portion 41L of the rear surface 41 of the rear cover 31, rather than the upper portion 41U. As shown in FIG13 , the lower portion 41L of the ink cartridge 30 placed in the second orientation intersects a first virtual plane P1 perpendicular to the insertion direction 51 (perpendicular to the drawing of FIG13 ) at an angle α. The length of the normal extending from the rotation center O toward the lower end of the lower portion 41L, perpendicular to the second virtual plane P2 of the lower portion 41L (perpendicular to the drawing of FIG13 ), will be denoted as N. Then, the following equation holds true.

(Bias force F) × cos α × (length N) > (gravity G) × (distance L)

In the above equation, the product of the gravity G and the distance L is equal to the magnitude of the moment that rotates the ink cartridge 30 in the clockwise direction in FIG. 12 , as in the above equation.

When the user inserts the ink cartridge 30 into the cartridge attachment unit 110, if the user presses the lower portion 41L of the ink cartridge 30 in the insertion direction 51 with a force U equivalent to at least the biasing force F, a moment having a strength equivalent to the product of at least the cos α component of the biasing force F and the length N is applied to the ink cartridge 30 in the counterclockwise direction in FIG 13 . Since the above equation holds true, even if the user presses the lower portion 41L of the ink cartridge 30 in the insertion direction 51, a moment is applied to the ink cartridge 30 in the counterclockwise direction in FIG 13 .

When removing the ink cartridge 30 from the cartridge attachment unit 110, the user presses the operating surface 92 downward. As shown in Figure 15, when the ink cartridge 30 is placed in the first orientation, the operating surface 92 is visible when the ink cartridge 30 is viewed in the downward direction 53, and the operating surface 92 is also visible when the ink cartridge 30 is viewed in the forward direction 57 (insertion direction 51). When the ink cartridge 30 is placed in the first orientation, the operating surface 92 faces the upward direction 54 and the removal direction 52. Therefore, when the user manipulates the operating surface 92 to remove the ink cartridge 30 located in the cartridge attachment unit 110, a force is applied to the ink cartridge 30 in the downward direction 53 and the insertion direction 51. Due to the force applied in the insertion direction 51, the locking surface 151 separates from the locking portion 145. Due to the force applied in the downward direction 53, the ink cartridge 30 rotates from the first orientation to the second orientation. When compared to a case where ink cartridge 30 rotates from the first orientation to the second orientation while locking surface 151 causes sliding with locking portion 145 , the force applied by the user to manipulation surface 92 to rotate ink cartridge 30 from the first orientation to the second orientation is reduced.

When the ink cartridge 30 is rotated from the first orientation to the second orientation, the locking surface 151 is located below the locking portion 145. The ink cartridge 30 is then moved in the removal direction 52 within the cartridge attachment unit 110 by the biasing force of the tension spring 114 and the coil spring 78. During removal of the ink cartridge 30 from the cartridge attachment unit 110, as the ink cartridge 30 moves in the removal direction 52 while the contacts 106 remain electrically connected to their corresponding electrodes 65, the contacts 106 slide on their corresponding electrodes 65. As the contacts 106 slide on their corresponding electrodes 65, shavings may be generated from the electrodes 65.

When the ink cartridge 30 is separated from the slider 107, the biasing force applied to the ink cartridge 30 in the removal direction 52 is eliminated, and thus the inertial force applied to the ink cartridge 30 disappears, and the movement of the ink cartridge 30 in the removal direction 52 is terminated. At this time, at least the rear cover 31 of the ink cartridge 30 is positioned outward beyond the opening 112 in the housing 101 of the cartridge attachment unit 110, so that the user can grasp the rear cover 31 and remove the ink cartridge 30 from the cartridge attachment unit 110.

<Effects in this embodiment>

With the ink cartridge 30 according to this embodiment, when the ink cartridge 30 is in the attached orientation, the optical receiving portion 62 of the liquid level detecting portion 60 is disposed above the IC board 64 in the upward direction 54. Therefore, shavings generated from the IC board 64 due to sliding with the contact member 106 are less likely to adhere to the optical receiving portion 62, and even if shavings are generated from the IC board 64, detection by the optical receiving portion 62 is less affected.

Since the IC board 64 is arranged further forward than the optical access portion 62 in the insertion direction 51, when the ink cartridge 30 is inserted into or removed from the box attachment unit 110, the optical access portion 62 does not pass through the part where shavings are generated from the IC board 64, that is, near the contact member 106, and therefore the shavings are difficult to adhere to the optical access portion 62.

Since the light receiving portion 62 has the side surfaces 66 and 67 , the state of the amount of ink remaining in the holding chamber 36 can be detected through the side surfaces 66 and 67 .

Since the size of the side surface 66 in the upward direction 54 is smaller than the size of the side surface 66 in the insertion direction 51, and the size of the side surface 67 of the optical access portion 62 in the upward direction 54 is smaller than the size of the side surface 67 of the optical access portion 62 in the insertion direction 51, the size of the optical access portion 62 in the downward direction 53 and the upward direction 54 is reduced.

Since the intervention wall 80 is provided between the IC board 64 and the light receiving portion 62 , the intervention wall 80 restricts the route along which the shavings generated from the IC board 64 move to the light receiving portion 62 .

Since the dimensions of the rear wall 82 of the intervention wall 80 in the right and left directions are greater than the distance between the first and second side surfaces 66 and 67 of the optical receiving portion 62 , the intervention wall can further restrict the route of the chips generated from the IC board 64 moving to the optical receiving portion 62 .

Since the dimensions of the intervention wall 80 in the forward and rearward directions 57 and 58 are larger than those in the right and left directions 55 and 56, the distance from the IC board 64 to the optical receiving portion 62 is extended. This makes it more difficult for shavings to reach the optical receiving portion 62.

Because the intervention wall 80 is provided closer to the light receiving portion 62 than the IC board 64 is to the light receiving portion 62 in the removal direction 52 , shavings generated from the IC board 64 can be easily restricted by the intervention wall 80 .

Since liquid level detecting portion 60 is configured to change the state of light transmitted from the first point toward the second point and incident on light incident portion 62 according to the amount of liquid stored in ink cartridge 30 , the amount of liquid stored in ink cartridge 30 can be detected.

Since the light access portion 62 is configured to allow light traveling from the first point toward the second point to pass through the light access portion 62, and the liquid detection portion 60 further includes a sensor arm 59, a portion 68 of the sensor arm 59 is configured to be located in the light access portion 62, wherein the portion 68 of the light attenuation portion 59 is configured to change the state of the light passing through the light access portion 62 depending on whether the amount of liquid stored in the ink cartridge 30 is less than a specified amount, the amount of liquid stored in the ink cartridge 30 can be detected based on the state of the light passing through the light access portion 62 and the position of the sensor arm 59.

Because when the amount of liquid stored in the cartridge 30 is greater than or equal to the specified amount, the portion 68 of the sensor arm 59 is positioned above the circuit board 64. This makes it more difficult for shavings to reach a height at which light passes through the light detecting portion 62 to detect the amount of liquid stored in the cartridge 30.

Because intervention wall 80 extends upward beyond sensor arm 59, which contacts the wall defining the end of light receiving portion 62 in forward direction 57, intervention wall 80 is positioned between IC board 64 and sensor arm 59. This placement of intervention wall 80 makes it difficult for shavings generated from IC board 64 to reach the position of sensor arm 59 where sensor 103 detects the sensor arm 59.

Since the recess 99 is displaced from the IC board 64 in the removal direction 52 on the upper surface 141 of the front cover 32, the shavings generated from the IC board 64 remain in the recess 99. This makes it difficult for the shavings to scatter.

The center of the IC board 64 is arranged to be closer to the side surface 66 of the optical access portion 62 than to the side surface 67. The light-emitting portion in the sensor 103 faces the side surface 67, and the light-sensitive portion in the sensor 103 faces the side surface 66, as described above. The distance that the chips generated from the IC board 64 move to the side surface 67 is greater than the distance that the chips move to the side surface 66. The light emitted from the light-emitting portion in the sensor 103 when the light exits the side surface 66 of the optical access portion 92 is diffused to a greater extent than when the light enters the side surface 67 of the optical access portion 62. Therefore, the possibility of the chips moving toward the side surface 66 is lower than the possibility of the chips moving toward the side surface 67. Therefore, on the side surface 66, even if the chips have moved to the optical access portion 62, the detection result of the sensor 103 is less affected.

When viewed in the downward direction 53 and the upward direction 54, the rotation axis 61 of the sensor arm 59 overlaps with the light receiving portion 62. Therefore, the portion of the light receiving portion 62 used for the rotation of the sensor arm 59 is reduced in the downward direction 53 and the upward direction 54. As a result, the size of the IC board 64 in the downward direction 53 and the upward direction 54 is reduced. As a result, the internal space of the light receiving portion 62 can be saved.

When viewed in the downward direction 53 and the upward direction 54, the IC board 64 overlaps the ink supply portion 34. This enables the ink cartridge 30 to be designed so that the distance between the IC board 64 and the light receiving portion 62 is extended.

Since the lower surface 89 of the first protrusion 85 is configured to limit the movement of the ink cartridge 30 in the upward direction 54 and the downward direction 53, and the lower surface 89 of the first protrusion 85 is set upward in the upward direction 54 relative to the ink outlet portion 34 and set downward in the upward direction 54 relative to the circuit board 64, the IC board 64 is accurately positioned to the contact member 106 in the downward direction 53 and the upward direction 54.

The optical receiving portion 62 is displaced from the IC board 64 in the removal direction 52, and the locking surface 151 is displaced from the optical receiving portion 62 in the removal direction 52. Therefore, when the circuit board 64, the optical receiving portion 62, and the locking surface 151 intersect with a virtual plane parallel to the insertion direction 51 and the upward direction 54, the size of the ink cartridge 30 in a direction orthogonal to the insertion direction 51 can be reduced. When the ink cartridge 30 is attached to the cartridge attachment unit 110, the positional accuracy of the IC board 64, which is disposed at the front end in the insertion direction 51, is high, so the IC board 64 is reliably connected to the contact 106. The locking surface 151, which is disposed at the rear end in the insertion direction 51, enables easy locking and unlocking operations, that is, easy rotation about the rotation center O. The range of rotation of the ink cartridge 30 for locking and unlocking can also be reduced.

In the removal direction 52, the optical receiving portion 62 is disposed closer to the locking surface 151 than the IC board 64 is to the locking surface 151. This enables the ink cartridge 30 to be designed so that the distance between the IC board 64 and the optical receiving portion 62 is extended. Consequently, a larger space can be secured for components such as the sensor arm 59 that change the state of the ink supply portion 34 and the optical receiving portion 62.

Because the upper end of the optical receiving portion 62 is closer to the locking surface 151 than the IC board 64 is to the locking surface 151 in the upward direction 54 , the optical receiving portion 62 can be set as high as possible, thereby easily ensuring the internal space of the holding chamber 36 .

The ink cartridge 30 includes a portion of the sensor arm 59 as a first light attenuating portion and an intervening wall 80 as a second light attenuating portion, and the first light attenuating portion and the second light attenuating portion are disposed above the circuit board 64. This enables the sensor for detecting the insertion of the ink cartridge 30 and the sensor 103 for detecting the liquid state in the ink cartridge 30 to be disposed in the upper region of the cartridge attachment unit 110. This enables the two sensors to be disposed on the same circuit board. Compared to a case where two circuit boards are provided for each of the two sensors, having a common circuit board contributes to cost and space reduction.

<Variation>

In the above-described embodiment, it has been pointed out that when the sensor arm 59 rotates in the light access portion 62, the passage state of light passing through the light access portion 62 changes. However, the change in the passage state of light passing through the light access portion 62 can be achieved by using other means besides the sensor arm 59. For example, light attenuation as a change in the state of light passing through the light access portion 62 can be achieved by using a light attenuation portion that is movable due to changes in the liquid level in the liquid holding chamber, or by using the side surface of the light attenuation portion to completely block the light. Alternatively, the light attenuation portion may absorb part of the light, may refract the light, or may totally reflect the light to attenuate the light. Another method may be used. The user can visually check the liquid level detection portion to grasp the amount of liquid remaining in the liquid holding chamber.

For example, the liquid level detection unit may include a light guide path as described in Japanese Unexamined Patent Application Publication No. 2005-313447. In this case, the incident portion 67 or the emitting portion 68 in the disclosure is equivalent to the light access portion. In addition, the liquid level detection unit may include a reflecting portion and a prism. That is, the light access portion may serve as a reflecting member that reflects light that travels from a first point to a second point and accesses the light access portion 62. Figures 16A and 16B are perspective views near the liquid detection unit in the ink cartridge; a cross-section of the portion in front of the reflecting member 800 is shown. Although not shown in Figures 16A and 16B, an IC board is provided on the upper surface 414 of the ink cartridge and in front of the reflecting member 800, and the reflecting member 800 is provided behind and above the IC board as part of the light access portion. As shown in Figure 16A, the reflecting member 800 is provided at a certain distance above the upper surface 414 of the ink cartridge. The reflective member 800 has reflective portions 801 and 802, which are formed of, for example, aluminum foil and can therefore reflect light. The upper surface 414 is made of a member through which light can pass. The prism 390 is formed at the upper end of the holding chamber 36. The prism 390 is disposed below the circuit board 64. The prism 390 is configured to reflect light according to the amount of liquid stored in the cartridge 30, and the reflective member 800 is configured to reflect light traveling from the emitting portion toward the prism (390A) or to reflect light at the prism (390B) toward the photosensitive portion.

In FIG16B , holding chamber 36 is completely filled with ink. When ink contacts surfaces 390A and 390B of prism 390 facing holding chamber 36, light emitted from the light-emitting portion of sensor 103 in right direction 55 (indicated by the dashed line in FIG16B ) is reflected in downward direction 53 by reflective portion 801, passes through surface 390A of prism 390, and enters holding chamber 36. If the ink in holding chamber 36 decreases and no longer contacts surfaces 390A or 390B of prism 390, as shown in FIG16A , light emitted from the light-emitting portion of sensor 103 and reflected in downward direction 53 by reflective portion 801 is reflected in right direction 55 by surface 390A of prism 390, propagates through prism 390, is reflected in upward direction 54 by surface 390B, and reaches reflective portion 802. Light reflected by reflective portion 802 reaches the photosensitive portion of sensor 103. As described above, the intensity of light received by the sensor 103 varies depending on the amount of ink remaining in the holding chamber 36, and thus a decrease in the remaining ink amount can be detected based on the detection signal from the sensor 103. Furthermore, in this modification, since the reflective portions 801 and 802 are provided above the IC board, shavings generated from the IC board can be prevented from adhering to the reflective portions 801 and 802.

The optical access portion can be defined as follows. Assume that there are positions A and B aligned in the right direction 55 and the left direction 56. When light (e.g., visible light or infrared light) traveling in the right direction 55 or the left direction 56 is emitted from position A, the light reaches position B with an intensity of I. When the optical access portion is located between position A and position B and the amount of liquid stored in the chamber 36 is greater than or equal to a predetermined amount, the light emitted from position A and traveling in the right direction 55 or the left direction 56 reaches one of the right and left surfaces of the optical access portion. When this occurs, the light exiting the other of the right and left surfaces of the optical access portion reaches position B with an intensity less than half of I, for example, with an intensity of zero. On the other hand, when the optical access portion is located between position A and position B and the amount of liquid stored in the chamber 36 is less than a predetermined amount, the light emitted from position A and traveling in the right direction 55 or the left direction 56 reaches one of the right and left surfaces of the optical access portion. When this happens, light exiting from the other of the right and left surfaces of the light receiving portion reaches position B with an intensity greater than or equal to half of I.

For example, the light-emitting portion of sensor 103 is placed at position A, and the light-receiving portion (photosensitive portion) of sensor 103 is placed at position B. When the light-receiving portion of sensor 103 is composed of a phototransistor, for example, when the phototransistor receives light with an intensity of I, the collector current value of the phototransistor is C. When the light receiving portion is located between positions A and B and the amount of liquid stored in chamber 36 is greater than or equal to a predetermined amount, light emitted from position A and traveling in the right direction 55 or the left direction 56 reaches one of the right and left surfaces of the light receiving portion. When this occurs, light emitted from the other of the right and left surfaces of the light receiving portion reaches position B with an intensity less than half of I, causing the collector current value of the phototransistor to become less than half of C, for example, to zero. On the other hand, when the light receiving portion is located between positions A and B and the amount of liquid stored in chamber 36 is less than the predetermined amount, light emitted from position A and traveling in the right direction 55 or the left direction 56 reaches one of the right and left surfaces of the light receiving portion. When this occurs, light exiting from the other of the right and left surfaces of the light receiving portion reaches position B with an intensity greater than or equal to half of I, which causes the collector current value of the phototransistor to become greater than or equal to half of C. In the above embodiment, side surface 66 corresponds to the right side surface of the light receiving portion, and side surface 67 corresponds to the left side surface of the light receiving portion.

The maximum dimension of the light receiving portion in the right direction 55 and the left direction 56 (in the above embodiment, the maximum distance between the side surface 66 and the side surface 67 in the right direction 55 and the left direction 56) is smaller than the maximum dimension of the ink cartridge 30 (in the above embodiment, the maximum distance between the side surface 143 or 37 and the side surface 144 or 38 in the right direction 55 and the left direction 56). With this configuration, the light emitting portion and the light receiving portion (photosensitive portion) of the sensor 103 can be placed close to each other, thereby improving the accuracy of liquid amount detection.

The optical access portion intersects with light traveling in the right direction 55 or the left direction 56, while the electrode 65 is accessed in the downward direction 53 perpendicular to the right direction 55 and the left direction 56. Therefore, if the electrode 65 is accessed in the downward direction 53 by the contact member 106 and the ink cartridge 30 should change its orientation, the ink cartridge 30 changes its orientation in the downward direction 53 and the upward direction 54 instead of in the right direction 55 and the left direction 56. Therefore, when the electrode 65 is accessed, the angle at which the light intersects the optical access portion does not change. If the angle at which the light intersects the optical access portion changes, this change will affect the detection of the amount of liquid. However, because the direction of light travel is perpendicular to the direction in which the electrode 65 is accessed, the angle at which the light intersects the optical access portion does not change, and the effect on the detection of the amount of liquid is reduced.

Although the slider 107 and the tension spring 114 are provided in the cartridge attachment unit 110 in the above embodiment, this arrangement is optional. For example, the cartridge attachment unit 110 may not have the slider 107 and the tension spring 114, and only the coil spring 78 in the ink supply portion 34 may be used to bias the ink cartridge 30 inserted into the cartridge attachment unit 110 in the removal direction 52.

Although the IC board 64 and the locking surface 151 are provided on different covers, the front cover 32 and the rear cover 31 in the above-described embodiment, the IC board 64 and the locking surface 151 may be provided on the same cover member.

Although the rear surface 82 of the intervention wall 80 has a Y-shaped portion and the Y-shaped rear surface 82 covers the front portion of the optical receiving portion 62, in other embodiments, the rear surface 82 of the intervention wall may have an I-shaped portion instead of a Y-shaped portion. In other words, the dimensions of the intervention wall 80 in the left and right directions may be smaller than the distance between the side surfaces 66 and 67 of the optical receiving portion.

Although ink has been described as an example of liquid in the above embodiment, for example, pre-treatment liquid ejected to a recording sheet during printing before ink is ejected may be held in a liquid tank. Alternatively, water for cleaning the recording head 21 may be held in a liquid tank.

Claims (19)

1. A liquid container, comprising: Front surface; The upper surface faces upward when the liquid cartridge is installed in the liquid consumption device; A liquid outlet portion, the liquid outlet portion facing a first direction at the front surface; Circuit board, the circuit board being disposed on the upper surface; and Liquid detection unit, which is used to detect the state of the liquid stored in the liquid box; The liquid detection unit includes a light access unit, which is configured to allow light to travel from a first point toward a second point. The optical access portion is positioned above the circuit board in the upward direction. 2. The liquid container according to claim 1, wherein the circuit board is displaced from the light access portion in the first direction. 3. The liquid container according to any one of claims 1 or 2, wherein the light access portion includes a first side surface and a second side surface, wherein each of the first side surface and the second side surface extends in the first direction and intersects the upper surface. 4. The liquid cartridge according to any one of claims 1 to 2, further comprising an intervention wall disposed between the circuit board and the light access portion, and the intervention wall comprising a designated surface extending in a second direction intersecting the first direction and the upward direction. 5. The liquid container according to claim 4, wherein the dimension of the designated surface of the intervention wall in the second direction is longer than the distance in the second direction between the first side surface and the second side surface of the light access portion. 6. The liquid container of claim 4, wherein the dimension of the intervention wall in the first direction is longer than the dimension of the intervention wall in the second direction. 7. The liquid cartridge of claim 4, wherein the intervention wall is configured to be closer to the light access portion than to the circuit board in the first direction. 8. The liquid container according to any one of claims 1 to 2, wherein the liquid detection unit is configured to: change the state of the light transmitted from the first point toward the second point and accessed by the light access unit according to the amount of liquid stored in the liquid container. 9. The liquid container according to any one of claims 1 to 2, wherein the light access portion is configured to allow light traveling from the first point toward the second point to pass through the light access portion, and the liquid detection portion further includes a light attenuation portion, a portion of which is configured to be located in the light access portion, wherein the portion of the light attenuation portion is configured to: change the state of the light passing through the light access portion depending on whether the amount of liquid stored in the liquid container is less than a specified amount. 10. The liquid container of claim 9, wherein when the amount of liquid stored in the liquid container is greater than or equal to the specified amount, the portion of the light attenuation section is disposed above the circuit board. 11. The liquid container of claim 4, wherein the light access portion is configured to allow light traveling from the first point toward the second point to pass through the light access portion, and the liquid detection portion further includes a light attenuation portion, a portion of which is configured to be located in the light access portion, wherein the portion of the light attenuation portion is configured to: change the state of the light passing through the light access portion depending on whether the amount of liquid stored in the liquid container is less than a specified amount; and When the amount of liquid stored in the box is greater than or equal to the specified amount, the intervention wall extends upward in the upward direction beyond the portion of the light attenuation section. 12. The liquid cartridge according to any one of claims 1 to 2, wherein the liquid cartridge is provided with a recess that is displaced upward from the circuit board in a third direction opposite to the first direction. 13. The liquid container of claim 3, wherein the center of the circuit board is positioned closer to the second side surface than to the first side surface. 14. The liquid cartridge of claim 9, further comprising a chamber configured to store the liquid therein, wherein the light attenuation portion is a sensor arm configured to rotate about an axis in the chamber, and when the sensor arm rotates, the portion of the sensor arm alters the state of the light passing through the light access portion. 15. The liquid cartridge of claim 14, wherein the light access portion is made of a transparent material, defines an internal space continuous with the chamber, and protrudes in the upward direction relative to the upper surface. 16. The liquid cartridge of claim 15, further comprising a body defining the chamber and a cover covering the body, wherein the light access portion is disposed on the body and the light access portion protrudes to the outside of the cover through an opening formed through the cover. 17. The liquid cartridge according to any one of claims 1 to 2, wherein when the circuit board is viewed in the upward direction, the circuit board overlaps with the liquid outlet. 18. The liquid cartridge according to any one of claims 1 to 2, further comprising a positioning surface configured to restrict movement of the liquid cartridge in the upward and downward directions, wherein the positioning surface is disposed above the liquid outlet in the upward direction and below the circuit board in the upward direction. 19. The liquid container according to any one of claims 1 to 2, wherein the light access portion is configured to: pass through the light access traveling from the first point toward the second point in a second direction perpendicular to the first direction and the upward direction.