JP2023039110A - Cleaning device, image formation device and winding control method - Google Patents

Abstract

[Problem] To provide a cleaning device, an image forming apparatus, and a winding control method capable of preventing waste of a cleaning member. [Solution] The cleaning device includes a cleaning member that comes into contact with the nozzle face of a head unit that forms an image on a recording medium by an inkjet head and cleans ink remaining on the nozzle face, a winding section that winds up the cleaning member so that the cleaning member comes into contact with the nozzle face, a dirt state detection section that detects the dirt state of the cleaning member after cleaning, and a control section that controls the winding section to rewind the cleaning member in accordance with the detected dirt state. [Selected Figure] Figure 4

Description

The present invention relates to a cleaning device, an image forming apparatus, and a take-up control method.

2. Description of the Related Art Conventionally, an inkjet image forming apparatus is known that forms (records) an image on a recording medium conveyed by a conveying device by ejecting ink from a plurality of nozzles provided in an inkjet head.

An inkjet head included in an inkjet image forming apparatus ejects ink from a plurality of nozzles. Pressure is applied to each nozzle individually, and ink ejection control is performed according to an image to be recorded. The ink ejection openings of the nozzles are aligned and open on one surface (nozzle surface) of the inkjet head facing the recording medium during image formation.

In the ink jet image forming apparatus having such a configuration, if foreign matter adheres to the nozzle surface, residual ink that has thickened after drying, air bubbles, or the like is present, it is impossible to perform good ink ejection for image formation. Therefore, head cleaning is performed to maintain a good ink ejection state.

As head cleaning, the ink inside the nozzles is discharged by applying pressure from the upstream side of the nozzles or by suction from the nozzle surface side. to be done.

After the ink is discharged as a cleaning operation, the ink remaining on the nozzle surface can be cleaned (removed) by a wiping operation in which a wiping member (cleaning member) is brought into contact with the nozzle surface and moved. (See Patent Document 1, for example). In the wiping operation, a wiping member such as a wiper blade for scraping ink or an absorbent sheet member is used.

In the technique described in Japanese Patent Application Laid-Open No. 2002-200001, the wiping member is wrapped around the nozzle surface of the recording head while the recording head and the wiping unit are moved relative to each other when the wiping member wipes the portion of the nozzle surface of the recording head where the nip portion of the cap member abuts. A take-up member is used to control the take-up.

JP 2018-94835 A

However, in the technique described in Japanese Patent Laid-Open No. 2003-100001, control is performed to wind up the cleaning member (wiping member) without considering the amount of ink actually remaining on the nozzle surface. When the amount of the cleaning member required for wiping off the ink is small, there is a problem that a large amount of the cleaning member is wound up and used, resulting in waste of the cleaning member.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cleaning device, an image forming apparatus, and a take-up control method capable of preventing wasteful occurrence of cleaning members.

A cleaning device according to the present invention includes:
a cleaning member that contacts a nozzle surface of a head unit that forms an image on a recording medium with an inkjet head and cleans ink remaining on the nozzle surface;
a winding unit that winds up the cleaning member so that the cleaning member is in contact with the nozzle surface;
a contamination state detection unit that detects the contamination state of the cleaning member after cleaning;
a control unit that controls the winding unit to rewind the cleaning member according to the detected staining state;
Prepare.

An image forming apparatus according to the present invention includes:
the cleaning device;
the head unit;
Prepare.

A winding control method according to the present invention includes:
a cleaning member that contacts a nozzle surface of a head unit that forms an image on a recording medium with an inkjet head and cleans ink remaining on the nozzle surface;
A winding control method for a cleaning device, comprising: a winding unit that winds up the cleaning member so that the cleaning member contacts the nozzle surface,
detecting the contamination state of the cleaning member after cleaning;
The winding section is controlled to rewind the cleaning member according to the detected dirt condition.

According to the present invention, it is possible to suppress the occurrence of waste in the cleaning member.

1 is a diagram showing a schematic configuration of an inkjet image forming apparatus; FIG. 3 is a schematic diagram showing the configuration of a head unit; FIG. 1 is a block diagram showing the main functional configuration of an inkjet image forming apparatus; FIG. 4A and 4B are diagrams for explaining the configuration and operation of the cleaning device; FIG. 5 is a flow chart showing an example of a winding control operation of the inkjet image forming apparatus;

FIG. 1 is a diagram showing a schematic configuration of an inkjet image forming apparatus 1 (functioning as an "image forming apparatus" of the present invention). The inkjet image forming apparatus 1 includes a paper feeding section 10, an image forming section 20, a paper discharging section 30, and a control section 40 (see FIG. 3).

The inkjet image forming apparatus 1 conveys the recording medium P stored in the paper feeding section 10 to the image forming section 20 under the control of the control section 40, forms an image on the recording medium P in the image forming section 20, and forms an image. The recording medium P on which is formed is conveyed to the paper discharge section 30 . As the recording medium P, in addition to paper such as plain paper and coated paper, it is possible to use various media such as cloth or sheet-like resin, on which ink that has landed on the surface can be fixed.

The paper feed unit 10 includes a paper feed tray 11 that stores the recording medium P, and a medium supply unit 12 that conveys and supplies the recording medium P from the paper feed tray 11 to the image forming unit 20 . The medium supply unit 12 includes a ring-shaped belt whose inner side is supported by two rollers, and the recording medium P is fed from the paper feed tray 11 by rotating the rollers while the recording medium P is placed on the belt. It is conveyed to the image forming section 20 .

The image forming section 20 includes a conveying section 21, a transfer unit 22, a heating section 23, a head unit 24, a fixing section 25, a delivery section 28, and the like.

The conveying unit 21 holds the recording medium P placed on a conveying surface 211a (mounting surface) of a cylindrical conveying drum 211, and the conveying drum 211 extends in the X direction (perpendicular to the paper surface of FIG. 1). The recording medium P on the conveying drum 211 is conveyed in the conveying direction (Y direction) by rotating around the rotating shaft (cylindrical shaft).

The conveying drum 211 includes a claw portion and a suction portion (not shown) for holding the recording medium P on the conveying surface 211a. The recording medium P is held on the transport surface 211a by being pressed at the ends by the claws and by being attracted to the transport surface 211a by the suction unit. The transport unit 21 is connected to a transport drum motor (not shown) for rotating the transport drum 211 . The conveying drum 211 rotates by an angle proportional to the amount of rotation of the conveying drum motor.

The delivery unit 22 delivers the recording medium P conveyed by the medium supply section 12 of the paper supply section 10 to the conveyance section 21 . The transfer unit 22 is provided at a position between the medium supply unit 12 and the transport unit 21 of the paper supply unit 10, and holds one end of the recording medium P transported from the medium supply unit 12 by the swing arm unit 221 and picks it up. , to the transfer section 21 via the delivery drum 222 .

The heating unit 23 is provided between the arrangement position of the delivery drum 222 and the arrangement position of the head unit 24, and heats the recording medium P so that the temperature of the recording medium P conveyed by the conveying unit 21 is within a predetermined temperature range. to heat. The heating unit 23 has, for example, an infrared heater or the like, and energizes the infrared heater based on a control signal supplied from the control unit 40 to cause the infrared heater to generate heat.

The head unit 24 ejects ink ejection openings (ink ejection openings) provided on a nozzle surface (ink ejection surface) facing the transport surface 211a of the transport drum 211 at appropriate timing according to the rotation of the transport drum 211 holding the recording medium P. An image is formed by ejecting ink onto the recording medium P from the nozzle openings). The head unit 24 is arranged such that the nozzle surface and the transport surface 211a are separated by a predetermined distance.

In the inkjet image forming apparatus 1 according to the present embodiment, the four head units 24 corresponding to the four color inks of yellow (Y), magenta (M), cyan (C), and black (K) are arranged on the recording medium P. The colors are arranged in the order of Y, M, C, and K from the upstream side in the conveying direction so as to be arranged at predetermined intervals.

FIG. 2 is a schematic diagram showing the configuration of the head unit 24. As shown in FIG. Here, the nozzle surface 245 of the head unit 24 facing the transport surface 211a of the transport drum 211 is shown.

The head unit 24 includes four inkjet heads 242 attached to mounting members 244 . Each of the inkjet heads 242 is provided with a pressure chamber for storing ink, a piezoelectric element provided on the wall surface of the pressure chamber, and a plurality of image forming elements (recording elements) each having a nozzle 243 . When a driving signal for deforming the piezoelectric element is input to this image forming element, the pressure chamber is deformed by the deformation of the piezoelectric element, the pressure in the pressure chamber changes, and ink is ejected from the nozzle 243 communicating with the pressure chamber. do.

In the inkjet head 242, two nozzle arrays are formed, which are made up of nozzles 243 arranged at equal intervals in a direction intersecting the conveying direction of the recording medium P (in this embodiment, a direction orthogonal to the conveying direction, i.e., the X direction). It is These two nozzle rows are provided such that the arrangement positions of the nozzles 243 are shifted from each other in the X direction by half the arrangement interval of the nozzles 243 in each nozzle row.

The four inkjet heads 242 are arranged in a houndstooth pattern so that the arrangement range of the nozzle rows in the X direction is seamlessly connected. The arrangement range in the X direction of the nozzles 243 included in the head unit 24 covers the width in the X direction of the area where an image is formed on the recording medium P conveyed by the conveying unit 21 . The position is fixed with respect to the rotating shaft of the conveying drum 211 during image formation. That is, the head unit 24 has a line head capable of ejecting ink over an image-formable width in the X direction with respect to the recording medium P, and the inkjet image forming apparatus 1 is a single-pass type inkjet image forming apparatus. is.

The number of nozzle rows that the inkjet head 242 has may be one or three or more instead of two. Also, the number of inkjet heads 242 included in the head unit 24 may be three or less or five or more instead of four.

As the ink ejected from the nozzles 243 of the image forming element, white ink containing pigment such as titanium dioxide is used. In addition, the ink ejected from the nozzle 243 of the image forming element contains a gelling agent, changes its phase to gel or sol depending on the temperature, and has the property of being cured by irradiation with energy rays such as ultraviolet rays. gel ink is used. In this embodiment, gel ink containing pigment is used as the ink ejected from the nozzles 243 of the image forming element.

The head unit 24 includes an ink heating section (not shown) that heats ink stored in the head unit 24 . The ink heating section operates under the control of the control section 40, and heats the ink to a sol-like temperature.

The inkjet head 242 ejects ink that has been heated and turned into a sol. When this sol-like ink is ejected onto the recording medium P, after the ink droplets land on the recording medium P, the ink quickly turns into gel and solidifies on the recording medium P due to natural cooling.

The fixing unit 25 has a light emitting unit arranged across the width of the transport unit 21 in the X direction, and the recording medium P placed on the transport unit 21 is irradiated with energy rays such as ultraviolet rays from the light emitting unit. Then, the ink (gel ink) ejected onto the recording medium P is cured and fixed. The light emitting section of the fixing section 25 is arranged to face the conveying surface 211a between the arrangement position of the head unit 24 and the arrangement position of the transfer drum 281 of the delivery section 28 in the conveying direction.

The delivery unit 28 has a cylindrical transfer drum 281 that transfers the recording medium P from the transport unit 21 to a belt loop 282, and a belt loop 282 that has a ring-shaped belt whose inner side is supported by two rollers. The transfer drum 281 transfers the recording medium P from the transfer section 21 onto the belt loop 282 , and the belt loop 282 transfers the recording medium P to the discharge section 30 .

The paper discharge section 30 has a plate-shaped paper discharge tray 31 on which the recording medium P delivered from the image forming section 20 by the delivery section 28 is placed.

In the inkjet image forming apparatus 1, if foreign matter adheres to the nozzle surface 245 on which the nozzles 243 for ejecting ink are formed, residual dried and thickened ink remains, air bubbles are mixed, etc., it is difficult to perform image formation. Ink cannot be discharged. Therefore, head cleaning is performed to maintain a good ink ejection state.

As head cleaning, a purge operation that forcibly discharges the ink in the nozzles by pressurizing from the upstream side of the nozzles or suctioning from the nozzle surface 245 side removes foreign matter, dried and thickened ink, mixed air bubbles, etc. along with the discharged ink. (purification) is done.

Further, after the ink is discharged as such a cleaning operation, ink remaining on the nozzle surface 245 is cleaned by a wiping operation in which a cleaning member is brought into contact with the nozzle surface 245 and moved. In the wiping operation, a cleaning member such as an absorbent sponge member or cloth member (for example, cloth or non-woven fabric) or a rubber blade (blade member) for scraping off ink is used.

FIG. 3 is a block diagram showing the main functional configuration of the inkjet image forming apparatus 1. As shown in FIG. The inkjet image forming apparatus 1 includes a heating unit 23, a head driving unit 241 and an inkjet head 242, a pressure contact/separation unit 246, a fixing unit 25, a control unit 40, a transport driving unit 51, an operation display unit 52, It has an input/output interface 53 , a cleaning device 55 , and a dirt state detector 90 .

The head driving unit 241 supplies the image forming elements of the inkjet head 242 with driving signals for deforming the piezoelectric elements according to the image data at an appropriate timing, so that the pixels of the image data are output from the nozzles 243 of the inkjet head 242. The amount of ink corresponding to the value is ejected.

The control unit 40 has a CPU 41 (Central Processing Unit), a RAM 42 (Random Access Memory), a ROM 43 (Read Only Memory) and a storage unit 44 .

The CPU 41 reads various control programs and setting data stored in the ROM 43, stores them in the RAM 42, and executes the programs to perform various arithmetic processing. Further, the CPU 41 centrally controls the overall operation of the inkjet image forming apparatus 1 .

The RAM 42 provides working memory space to the CPU 41 and stores temporary data. RAM 42 may include non-volatile memory.

The ROM 43 stores programs for various controls executed by the CPU 41, setting data, and the like. A rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used instead of the ROM 43 .

The storage unit 44 stores a print job (image forming command) input from the external device 2 via the input/output interface 53, image data related to the print job, and the like. Among these, the print job includes information specifying image data relating to an image to be formed and information relating to the type of the recording medium P on which the image is to be formed (for example, the size and thickness of the recording medium P). As the storage unit 44, for example, an HDD (Hard Disk Drive) is used, and a DRAM (Dynamic Random Access Memory) or the like may be used together.

The transport drive unit 51 supplies a drive signal to the transport drum motor of the transport drum 211 based on the control signal supplied from the control unit 40 to rotate the transport drum 211 at a predetermined speed and timing.

Further, the transport drive unit 51 supplies drive signals to motors for operating the medium supply unit 12, the transfer unit 22, and the delivery unit 28 based on control signals supplied from the control unit 40, thereby feeding the recording medium P. Supply to the transport section 21 and discharge from the transport section 21 are performed.

The operation display unit 52 includes a display device such as a liquid crystal display or an organic EL display, and an input device such as an operation key and a touch panel arranged over the screen of the display device. The operation display unit 52 displays various types of information on the display device, converts the user's input operation to the input device into an operation signal, and outputs the operation signal to the control unit 40 .

The input/output interface 53 mediates transmission and reception of data between the external device 2 and the control unit 40 . The input/output interface 53 is composed of, for example, various serial interfaces, various parallel interfaces, or a combination thereof.

The external device 2 is, for example, a personal computer, and supplies print jobs, image data, and the like to the control section 40 via the input/output interface 53 .

The cleaning device 55 cleans ink remaining on the nozzle surface 245 of the head unit 24 by a wiping operation of moving the head unit 24 while the cleaning member 70 (see FIG. 4) is in contact with the nozzle surface 245 of the head unit 24 . In this embodiment, an absorbent cloth member (for example, cloth or non-woven fabric) is used as the cleaning member 70 .

4A and 4B are diagrams for explaining the specific configuration and operation of the cleaning device 55. FIG. As shown in FIG. 4 , the cleaning device 55 is stretched between a delivery roller 62 , a take-up roller 64 (functioning as a “winding unit” of the present invention), and the delivery roller 62 and the take-up roller 64 . and a cleaning member 70 and a contamination state detector 90 . Note that the control unit 40 and the cleaning device 55 function as the "cleaning device" of the present invention.

The delivery roller 62 delivers the wound cleaning member 70 while rotating under the control of the control unit 40 . The take-up roller 64 rotates and winds the cleaning member 70 delivered by the delivery roller 62 under the control of the control unit 40 .

A backup member 61 that supports the cleaning member 70 from below is provided between the delivery roller 62 and the take-up roller 64 . The backup member 61 is, for example, a flat plate-like member made of a porous body (for example, porous ceramic or liquid-permeable resin) that is permeable to air. The backup member 61 is parallel to the nozzle surface 245 of the head unit 24 and is brought into contact with the inside of the cleaning member 70 to support the cleaning member 70 so as to be parallel to the nozzle surface 245 .

The pressure contact/separation part 246 (see FIG. 3) has a known structure, and moves the head unit 24 downward under the control of the control part 40 to press the nozzle surface 245 of the head unit 24 against the cleaning member 70 . The nozzle surface 245 of the head unit 24 is separated from the cleaning member 70 by (contacting) or moving the head unit 24 upward.

FIG. 4A shows the state before cleaning by the cleaning device 55 is performed. In this state, the control section 40 controls the pressure separation section 246 to move the head unit 24 upward, thereby separating the nozzle surface 245 of the head unit 24 from the cleaning member 70 . Ink 80 remains on the nozzle surface 245 of the head unit 24 .

FIG. 4B shows a state in which cleaning is being performed by the cleaning device 55 . In this state, the control section 40 controls the pressure contact/separation section 246 to move the head unit 24 downward, thereby bringing the nozzle surface 245 of the head unit 24 into pressure contact with the cleaning member 70 .

In this embodiment, in a state where the nozzle surface 245 is pressed against the cleaning member 70 , the cleaning member 70 is wound up by the take-up roller 64 and a wiping operation (rubbing operation) is performed to move the head unit 24 . Cleaning is performed by causing the cleaning member 70 to absorb (adsorb) the ink 80 .

The contamination state detector 90 is provided between the backup member 61 and the take-up roller 64 in the winding direction of the cleaning member 70, and detects the contamination state of the cleaning member 70 after cleaning. In the present embodiment, the contamination state detection unit 90 irradiates the cleaning member 70 after cleaning with light, receives the reflected light (for example, regular reflected light and diffuse reflected light), and determines the amount of the received reflected light. It is a reflective optical sensor that outputs an electrical signal corresponding to The contamination state detection unit 90 detects the contamination state of the cleaning member 70 by optically detecting the concentration of the ink 80 absorbed (adhered) onto the cleaning member 70 during cleaning.

FIG. 4C shows the state after cleaning by the cleaning device 55 is performed. In this state, the control section 40 controls the pressure separation section 246 to move the head unit 24 upward, thereby separating the nozzle surface 245 of the head unit 24 from the cleaning member 70 .

In the next cleaning by the cleaning device 55, the control section 40 controls the pressure contact/separation portion 246 to move the head unit 24 downward, thereby bringing the nozzle surface 245 of the head unit 24 into pressure contact with the cleaning member 70 (FIG. 4B). ). Thereafter, with the nozzle surface 245 in contact with the cleaning member 70 , the ink 80 remaining on the nozzle surface 245 is removed by a wiping operation (rubbing operation) in which the cleaning member is wound up by the winding roller 64 and the head unit 24 is moved. Cleaning is performed by causing the cleaning member 70 to absorb (adsorb) the liquid (see FIG. 4B).

By the way, in the conventional technique (the technique described in Patent Document 1), control is performed to wind up the cleaning member (wiping member) without considering the amount of ink actually remaining on the nozzle surface, so the amount of ink is small. In other words, when the amount of the cleaning member required for wiping off the ink is small, there is a problem that a larger amount of the cleaning member than necessary is wound up and used, resulting in waste of the cleaning member. rice field.

Therefore, in the present embodiment, for the purpose of suppressing the occurrence of waste in the cleaning member, the control unit 40 detects the dirt state (ink 80 density), the take-up roller 64 is controlled to unwind the cleaning member 70 (see FIG. 4D). Specifically, the controller 40 rewinds the cleaning member 70 when the detected density of the ink 80 is equal to or less than the threshold, and rewinds the cleaning member 70 when the detected density of the ink 80 is not equal to or less than the threshold. Control not to return. By performing such control, when the amount of ink wiped off by the cleaning member 70 is small, that is, when the amount of the cleaning member 70 necessary for wiping off the ink is small, the portion wiped off is rewound. reused for the next cleaning. As a result, when the amount of ink wiped off by the cleaning member 70 is small, it is possible to prevent an excessive amount of the cleaning member 70 from being wound up and used, thereby preventing the cleaning member 70 from being wasted. can.

Next, the winding control operation of the inkjet image forming apparatus 1 will be described. FIG. 5 is a flow chart showing an example of the winding control operation of the inkjet image forming apparatus 1 (corresponding to the "winding control method" of the present invention). Step S100 in FIG. 5 starts when an instruction to perform head cleaning is issued in the inkjet image forming apparatus 1 .

First, the control section 40 controls the pressure contact/separation section 246 to move the head unit 24 downward to press the nozzle surface 245 of the head unit 24 against the cleaning member 70 (step S100).

Next, the controller 40 controls the winding roller 64 to start winding the cleaning member 70 (step S120). As a result, a wiping operation (rubbing operation) for moving the head unit 24 is performed, and the ink 80 remaining on the nozzle surface 245 is absorbed (absorbed) by the cleaning member 70 for cleaning.

Next, the control unit 40 controls the winding roller 64 so as to end the winding operation of the cleaning member 70 at the timing when the ink 80 remaining on the nozzle surface 245 is cleaned (step S140).

Next, the control section 40 controls the pressure separation section 246 to move the head unit 24 upward, thereby separating the nozzle surface 245 of the head unit 24 from the cleaning member 70 (step S160).

Next, the control unit 40 acquires the detection result of the contamination state detection unit 90, specifically, the density of the ink 80 as the contamination state of the cleaning member 70 (step S180). Next, the control unit 40 determines whether or not the acquired density of the ink 80 is equal to or less than the threshold (step S200). As a result of the determination, if the density of the ink 80 is not equal to or lower than the threshold (step S200, NO), there is no portion that can be reused for the next cleaning, so the inkjet image forming apparatus 1 terminates the winding control operation.

On the other hand, if the density of the ink 80 is equal to or less than the threshold (step S200, YES), there is a portion that can be reused for the next cleaning, so the controller 40 starts the rewinding operation of the cleaning member 70. The take-up roller 64 is controlled (step S220). Finally, the control unit 40 controls the cleaning member 70 at the timing when the cleaning member 70 is wound up by a distance corresponding to the portion wiped off by the cleaning member 70 (the portion that can be reused for cleaning) in the winding direction of the cleaning member 70 . The winding roller 64 is controlled to end the rewinding operation (step S240). By completing the process of step S240, the inkjet image forming apparatus 1 ends the winding control operation.

As described above in detail, the inkjet image forming apparatus 1 (image forming apparatus) according to the present embodiment contacts the nozzle surface 245 of the head unit 24 that forms an image on the recording medium P with the inkjet head 242, and the nozzle surface a cleaning member 70 that cleans ink 80 remaining on 245; a winding unit (winding roller 64) that winds cleaning member 70 so that cleaning member 70 contacts nozzle surface 245; and cleaning member 70 after cleaning. A dirt state detection unit 90 for detecting a dirt state and a control unit 40 for controlling a winding unit to rewind the cleaning member 70 according to the detected dirt state (concentration of the ink 80) are provided. Specifically, in cleaning, when the density of the ink 80 detected as the dirty state is equal to or less than a threshold value, the control unit 40 controls the cleaning member 70 to rewind.

According to this embodiment configured as described above, when the amount of ink wiped off by the cleaning member 70 is small, that is, when the amount of the cleaning member 70 required for wiping off the ink is small, the wiped portion is rewound and reused for the next cleaning. As a result, when the amount of ink wiped off by the cleaning member 70 is small, it is possible to prevent an excessive amount of the cleaning member 70 from being wound up and used, thereby preventing the cleaning member 70 from being wasted. can.

In the above-described embodiment, the control unit 40 uses a threshold value (the (see step S200) may be changed. For example, when the color of the ink 80 remaining on the nozzle surface 245 is dark, the control unit 40 tends to increase the density of the ink 80 detected by the contamination state detection unit 90 relative to the amount of the ink 80. Therefore, the threshold value used for determining whether or not the rewinding operation of the cleaning member 70 is executed is increased. On the other hand, when the color of the ink 80 remaining on the nozzle surface 245 is light, the control unit 40 tends to make the density of the ink 80 detected by the contamination state detection unit 90 small relative to the amount of the ink 80. Therefore, the threshold value used for determining whether or not the rewinding operation of the cleaning member 70 is executed is increased. From a similar point of view, the control unit 40 may change the threshold according to the type of ink 80 remaining on the nozzle surface 245 (eg, dye ink, pigment ink).

Further, in the above embodiment, the control section 40 may change the winding speed of the cleaning member 70 in the next cleaning according to the contamination state detected by the contamination state detection section 90 . For example, when the density of the ink 80 as the dirt state detected by the dirt state detection unit 90 is high, the control unit 40 needs to increase the cleaning force of the cleaning member 70 because the ink 80 tends to remain on the nozzle surface 245 . Therefore, regardless of whether or not the cleaning member 70 is rewound, the take-up speed of the cleaning member 70 in the next cleaning is increased to increase the liquid absorption frequency of the cleaning member 70 . In addition, the control unit 40 winds the cleaning member 70 so as to change the winding speed of the cleaning member 70 in a plurality of steps according to the contamination state (for example, a plurality of contamination levels) detected by the contamination state detection unit 90. Rollers 64 may be controlled.

Further, in the above-described embodiment, the single-pass type inkjet image forming apparatus 1 is described as an example, but the present invention may be applied to an inkjet image forming apparatus that records an image while scanning the head unit. . Also, the present invention may be applied to an inkjet image forming apparatus in which a single nozzle is provided in the head unit.

Moreover, the above-described embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be construed to be limited by these. Thus, the invention may be embodied in various forms without departing from its spirit or essential characteristics.

Reference Signs List 1 inkjet image forming apparatus 2 external device 10 paper feed section 11 paper feed tray 12 medium supply section 20 image forming section 21 transport section 211 transport drum 211a transport surface 22 delivery unit 23 heating section 24 head unit 241 head drive section 242 inkjet head 243 Nozzle 244 Mounting member 245 Nozzle surface 246 Pressure contact/separation part 25 Fixing part 28 Delivery part 30 Paper discharge part 31 Paper discharge tray 40 Control part 41 CPU
42 RAM
43 ROMs
44 storage unit 51 transport drive unit 52 operation display unit 53 input/output interface 55 cleaning device 61 backup member 62 delivery roller 64 take-up roller 70 cleaning member 80 ink 90 dirt state detection unit P recording medium

Claims (10)

a cleaning member that contacts a nozzle surface of a head unit that forms an image on a recording medium with an inkjet head and cleans ink remaining on the nozzle surface;
a winding unit that winds up the cleaning member so that the cleaning member is in contact with the nozzle surface;
a contamination state detection unit that detects the contamination state of the cleaning member after cleaning;
a control unit that controls the winding unit to rewind the cleaning member according to the detected staining state;
cleaning device. The contamination state detection unit optically detects the contamination state of the cleaning member.
2. A cleaning device according to claim 1. The contamination state detection unit detects the contamination state of the cleaning member by detecting the density of ink adhering to the cleaning member.
3. A cleaning device according to claim 1 or 2. The control unit controls the winding unit to rewind the cleaning member when the detected density is equal to or less than a threshold.
4. A cleaning device according to claim 3. wherein the control unit changes the threshold according to the color of ink remaining on the nozzle surface;
5. A cleaning device according to claim 4. wherein the control unit changes the threshold according to the type of ink remaining on the nozzle surface;
6. A cleaning device according to claim 4 or 5. The control unit controls the winding unit to change the winding speed of the cleaning member in the next cleaning according to the detected dirt condition.
The cleaning device according to any one of claims 1-6. The control unit controls the winding unit so as to change the winding speed of the cleaning member in the next cleaning in a plurality of steps according to the detected dirt condition.
8. A cleaning device according to claim 7. a cleaning device according to any one of claims 1 to 8;
the head unit;
An image forming apparatus comprising: a cleaning member that contacts a nozzle surface of a head unit that forms an image on a recording medium with an inkjet head and cleans ink remaining on the nozzle surface;
A winding control method for a cleaning device, comprising: a winding unit that winds up the cleaning member so that the cleaning member contacts the nozzle surface,
detecting the contamination state of the cleaning member after cleaning;
controlling the winding unit to rewind the cleaning member according to the detected dirt condition;
Winding control method.

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