JP2003029564A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a peeling member having structure which is not deformed by heat, so that it neither causes uneven gloss on an image nor damages the image after peeling and to provide an image forming device equipped with the peeling member. SOLUTION: This image forming device is equipped with an acting member arranged in the carrying path of a recording medium and coming into contact with the recording medium just being carried so as to take specified action on the recording medium, and the plate type peeling member whose one side is arranged in contact with or proximately to the acting member and which peels the recording medium just being carried from the acting member. The surface of the peeling member on a side with which the recording medium just being carried comes into contact is formed to be a rough surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine or a facsimile, and more particularly to an image forming apparatus provided with a peeling device for peeling a recording medium carrying a toner image.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a facsimile, a toner image is formed, the toner image is transferred onto a sheet, and a pair of fixing members internally having a heat source are provided. The unfixed toner image on the paper is passed through the nip part formed by pressing and the toner image is heated and pressed to melt, and the melted toner image is permeated and fixed on the paper and fixed on the paper. A fixing device for forming an image composed of images is widely used.

However, when the toner is melted by the fixing device, the melted toner image may adhere to the fixing member side, and the adhered toner image may be offset on another sheet. Therefore, it is common to avoid such offset by using a release agent supply device that supplies a release agent to the fixing member to prevent the toner image from adhering.

However, in the fixing device using the releasing agent supply device, when the releasing agent is excessively transferred onto the paper through the fixing member, the paper is attached with an adhesive tape, a ball-point pen, a water-based pen, a pencil or the like. There is a problem that you will not be able to edit with. When fixing a toner image on an OHP sheet or the like, the transparency of the OHP sheet or the like decreases due to the transfer of the release agent, and the color image does not develop even when the sheet or the like is projected on the OHP sheet. There is also the problem of getting out.

In order to solve these problems, Japanese Unexamined Patent Publication No. Hei 11
Japanese Patent Laid-Open No. 184300 discloses a fixing device having a structure in which a releasing layer made of a fluororesin is provided on a fixing member, wax is contained in toner, and a peeling member is used to separate a sheet from the fixing member. There is.

According to the disclosed fixing device, since the release agent supplying device is not required, the problems such as the writing property due to the transfer of the release agent to the paper are improved.

However, when a releasing layer made of a fluororesin is provided on the fixing member, the releasing layer on the surface of the fixing member is damaged by the contact type releasing nail which has been widely used in the past. Even if it is a non-contact type, since the peeling claws are provided in various places in the axial direction of the fixing member, the sheet peeled by the peeling claws receives a local pressure. Since the local pressure may damage an image formed of a fixed toner image formed on a sheet, the disclosed fixing device includes a peeling member having a new structure in place of the peeling claw.

This new separating member has a planar structure,
The toner image is fixed on the paper after applying a uniform pressure over the entire axial direction of the fixing member, and the image is not damaged by the peeling member. There is an advantage that there is less chance of scratching the.

A fixing device having a planar structure and provided with a peeling member for peeling a sheet with a uniform pressure in the entire axial direction of the fixing member is disclosed in Japanese Patent Application Laid-Open Nos. 11-133776 and 20.
It is also disclosed in Japanese Patent Publication No. 00-98791.

[0010]

However, the peeling member having a planar structure provided in the fixing device disclosed in Japanese Patent Application Laid-Open No. 11-184300 uses a heat-resistant plastic sheet such as polyimide resin as its base material. As a result, distortion occurs due to the difference in the coefficient of thermal expansion between the sheet and the support plate that supports the sheet, and the sheet deforms into a wave shape due to the heat received from the fixing member, which interferes with sheet ejection and induces a jam. There is.

On the other hand, a metal substrate is used as the peeling member, a mold release agent is coated on the metal substrate to form a mold release layer, or an elastic body is provided between the metal substrate and the mold release layer. In order to improve the peeling performance regardless of the method of forming the layer or the paper type, the tip of the peeling member having the elastic layer formed on the metal substrate, which is close to the fixing member surface, is obliquely cut and peeled. A method of narrowing the gap between the peeling side of the member and the surface of the fixing member can be considered.

However, since the peeling member is arranged close to the fixing member, the peeling member receives heat from the fixing member to reach a high temperature, and the sheet coming out from the nip portion has a high-temperature planar structure with the peeling member. You will come into contact. Therefore, the image immediately after fixing and the already fixed image formed on the back surface of the paper are re-melted, and the melted image is rubbed by the peeling member having a flat structure, so that the gloss of the image becomes uneven, so-called gloss unevenness occurs. However, there is a problem that the sheet sticks to the peeling member due to the melted image.

Further, even in an apparatus other than the fixing apparatus, the toner image on the sheet may come into surface contact with the peeling member having a flat structure, and the toner image on the sheet may be rubbed and damaged.

In view of the above circumstances, the present invention has a structure that does not deform due to heat, and causes uneven gloss when peeling a sheet,
An object of the present invention is to develop a peeling member that does not cause image damage, and to provide an image forming apparatus including the peeling member.

[0015]

An image forming apparatus of the present invention that achieves the above object forms a toner image, and finally transfers and fixes the formed toner image onto a recording medium to thereby form the recording medium. In an image forming apparatus for forming an image composed of a fixed toner image thereon, an action member disposed on a conveyance path of a recording medium to come into contact with a recording medium being conveyed to exert a predetermined action on the recording medium, and one side has the above-mentioned action. A plate-shaped peeling member that is provided in contact with or close to the member and that peels the recording medium being conveyed from the acting member, wherein the peeling member has a rough surface on the side contacting the recording medium being conveyed. It is characterized by being formed.

Here, a pair of fixing members for fixing the toner image on the recording medium by sandwiching and heating the recording medium being conveyed are provided, and the acting member is one of the pair of fixing members. It may be one of the fixing members.

Further, the peeling member includes a metal substrate and a release layer which covers at least the surface of the metal substrate on the side where the peeling member contacts the recording medium and which prevents the adhesion of the molten toner on the recording medium. It is preferable that the release layer has a rough surface.

Further, it is preferable that the peeling member has a surface on the side in contact with the recording medium with a rough surface having an Rz value of 3 μm or more and less than 20 μm.

Further, it is also preferable that the peeling member has an elastic layer or a resin layer between the metal substrate and the release layer.

It is also preferable that the elastic layer or resin layer of the peeling member has a rough surface on the surface in contact with the release layer.

Further, it is preferable that the resin layer is formed of a heat resistant and abrasion resistant resin.

Further, the peeling member has the elastic layer or the resin layer only in a region of the metal substrate on a side where the peeling member comes into contact with or comes close to the acting member, and It is also a preferred embodiment that the surface of the layer has different surface roughness between the region of the release layer formed on the elastic layer or the resin layer and the region excluding the region.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the image forming apparatus of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a tandem type color printer to which the first embodiment of the present invention is applied.

The color printer of the present embodiment has R, G,
An input unit for inputting the image data represented by B, an image processing unit for performing color conversion of the input image data and gradation correction using a look-up table, and an image output terminal (image output terminal). Hereinafter, referred to as IOT). The input unit generates image data represented by R, G, B, and the image processing unit performs color conversion of the image data into Y, M, C, K and performs predetermined gradation correction and the like. Here, the input unit and the image processing unit are not shown, and an IOT that forms an image based on the image-processed image data will be mainly described.

The IOT of the color printer shown in FIG. 1 comprises an intermediate transfer belt 50 which carries a toner image on the surface thereof and circularly moves in the direction of arrow A, a plurality of rolls 51 which stretch the intermediate transfer belt 50, and an intermediate transfer belt. Yellow (Y), magenta (M), cyan (C), and black (K) toner images that are arranged in series along the circulating movement direction of the belt 50 and form a toner image on the surface are formed. Four photoconductor drums 52, a charger 53 that uniformly charges the photoconductor drums 52, and exposure light driven by a driver is applied to the surface of each of the charged photoconductor drums 52 to form an electrostatic latent image. The exposure device 54 to be formed and the electrostatic latent image on the surface of each photoconductor drum 52 are colored in yellow (Y), magenta (M),
Each developing device 55 that develops with cyan (C) and each color toner of black (K) to form a toner image, and the developed toner image formed on the surface of each photoconductor drum 52 onto the intermediate transfer belt 50. Each primary transfer device 56 for transferring, a secondary transfer device 59 for transferring the toner image on the intermediate transfer belt 50 onto a recording medium 58 fed from a paper feed tray 57, and a nip portion 60b by a pair of fixing members 60a. And a fixing device 60 that heats and presses an unfixed toner image with the recording medium 58 sandwiched in the nip portion 60b. Further, on the exit side of the recording medium 58 of the nip portion 60b, the nip portion 6 is provided at a position near each of the pair of fixing members 60a.
The recording medium 58 coming out of
Two peeling members 61 (not shown here) that peel from each a are provided. Each photoconductor drum 52 has a cleaner 62 for cleaning the toner remaining on each photoconductor drum 52 after being transferred to the intermediate transfer belt 50. The intermediate transfer belt 50 also transfers the cleaner 62 to the recording medium. There is a belt cleaner 63 for cleaning the toner remaining on the intermediate transfer belt after fixing.

Image data input from an input unit (not shown) and subjected to color conversion and gradation correction by an image processing unit (not shown) is pulse width modulated (PWM) for each color of Y, M, C and K.
The resulting image signal is input to each exposure device 54 via the driver. Each of the exposure devices 54 irradiates the photoconductor drum 52, which is uniformly charged by the charger 53, with exposure light based on the pulse-width-modulated image signal, and the photoconductor drums 5 are exposed.
An electrostatic latent image is formed on 2. The electrostatic latent image on each photoconductor drum 52 is developed by the developing device 55 to become a toner image of each color. Each color toner image on each photoconductor drum 52 is sequentially transferred onto the intermediate transfer belt 50 by each primary transfer device 56. The unfixed toner image on the intermediate transfer belt 50 is transferred onto the recording medium 58 sent from the paper feed tray 57 by the secondary transfer device 59, and the transferred unfixed toner image on the recording medium is fixed by the fixing device. The recording medium 58 is sandwiched by the nip portion 60b of 60 and is heated and pressurized, and an image composed of a fixed toner image is formed on the recording medium 58. The recording medium 58 on which the fixed toner image is formed and which has come out of the nip portion 60b is separated by the peeling member 61.
It is peeled off (not shown here) and sent downstream in the process direction.

The toner remaining on the photosensitive drums 52 after being sequentially transferred onto the intermediate transfer belt 50 is removed by the cleaner 62 from the toner remaining on the intermediate transfer belt 50 after being transferred onto the recording medium 58. Belt cleaner 6
It is cleaned at 3. Although the image forming apparatus using the intermediate transfer belt 50 is shown here, the intermediate transfer belt 50 may be replaced by a conveyor belt that carries a recording medium and circulates. Further, the developing device 55 is
Here, a one-cycle type one provided for each photosensitive drum 52 is used, but with one photosensitive drum,
The developing device may be a four-cycle developing device equipped with toner of each of four colors, and the fixing device 60 may be a transfer fixing device that simultaneously performs transfer and fixing.

Further, the image forming apparatus does not necessarily have to form a color image but may form a monochrome image. Further, although the peeling member is used for peeling the recording medium from the fixing member, the peeling of the recording medium is not limited to the fixing member, and the recording medium is separated from the acting member other than the fixing member that acts on the recording medium. It can also be used for peeling.

Next, the relationship between the fixing device and the peeling member used in this embodiment will be described.

FIG. 2 is a perspective view showing the fixing device and the peeling member used in the first embodiment.

As shown in FIG. 2, in the fixing device 60, a heating roll 65 having a heat source inside and heating the toner image at the nip portion is pressed against the heating roll 65, and the nip portion is formed between the heating roll 65 and the heating roll 65. A pressure roll 66 for forming a toner image 60b and pressing the toner image on the recording medium passing through the nip portion 60b;
The left and right upper frames 67 that support the heating roll 65, the left and right lower frames 68 that support the pressure roll 66, and the rotary shaft support member 69 of the pressure roll 66 are provided. Side frame 68
And are rotatably joined by first studs 70 provided on the left and right.

Although not shown here, both the heating roll 65 and the pressure roll 66 are made of a metallic substrate roll having a heat source therein, an inner elastic layer covered with the substrate roll, and an inner elastic layer. It has a surface layer covered with a body layer and formed of a fluororesin or the like having a good releasing property. The heating roll 65 and the pressure roll 66 form a nip portion with an appropriate pressure by the elastic action of the inner elastic layer, and heat and pressurize the recording medium passing through the nip portion.
The releasing action of the surface layer prevents the unfixed toner image on the recording medium from being offset to the heating roll 65.

The peeling member is a plate-like peeling member 61a for peeling the recording medium coming out of the nip from the heating roll 65.
U for supporting the peeling member 61a and the peeling member 61a on the upper frame 67
The groove member 71 and the pressing member 72 having a spring function of pressing the peeling member 61a toward the heating roll 65 side.
And a plate-shaped peeling member 61b for peeling the recording medium from the pressure roll 66 and the second stud 7 for rotatably supporting the peeling member 61b on the rotation shaft support member 69 of the pressure roll 66.
3 and the peeling member 61b are configured by a stopper member 74 that prevents the pressure roller 66 from being bitten more than a predetermined amount.

FIG. 3 is a side view showing the fixing device and the peeling member used in the first embodiment.

As shown in FIG. 3, the upper frame 67 and the lower frame 68 are rotatably connected by a first stud 70, and the side surface of the heating roll 65 supported by the upper frame 67 and the lower frame 68 and the rotation. Shaft support member 6
A nip portion is formed by the side surface of the pressure roll 66 supported by 9. A guide member 75 for guiding the recording medium for fixing the toner image to the nip portion is provided near the left of the nip portion, and the recording medium coming out of the nip portion from the heating roll 65 is provided near the right portion of the nip portion. Peeling member 6 for peeling
1a, a U-groove member 71 that movably supports the peeling member 61a with respect to the upper frame 67, a peeling member 61b that peels the recording medium coming out of the nip portion from the pressure roll 68, and the peeling member 61b. There is a hidden second stud 73 which supports the shaft supporting member 69.

FIG. 4 is a transparent view of a side view of the entire fixing device to which the peeling member shown in FIG. 3 is attached.

The same components as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 4, the peeling member 61b on the pressure roll 66 side receives a downward force in the figure by a tension spring 76 attached to the lower frame 68, so that the pressure roll of the peeling member 61b is pressed. The peeling action side 61c that contacts with is pressed so as to bite into the roll surface of the pressure roll 66. However, when the peeling action side 61c bites into the roll surface of the pressure roll 66 to some extent, the protrusion 61d of the supporting member of the peeling member 61b hits the second stud 74, so that the peeling action side 61c further extends. It is configured not to cut into. Further, the peeling member 61b is configured so that the peeling action side 61c does not separate from the roll surface of the pressure roll 66 even if a paper jam occurs.
The bent portion 77 of the upper frame prevents the space from being separated from the roll surface.

FIG. 5 is a side view when the upper frame is rotated to separate the heating roll and the pressure roll for maintenance and the like, and FIG. 6 is a perspective view thereof.

The same components as those in FIGS. 2 to 4 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 5 and 6, since the upper frame 67 and the lower frame 68 are rotatably joined by the first studs 70, the heating roll 65 is placed on the upper side during maintenance or the like. It can be rotated rightward in the figure together with the frame 67 to open a space between the frame 67 and the pressure roll 66. Further, the peeling member 6 attached to the pressure roll 66
1b is rotatably attached to the lower frame 68 by the second stud 73, but normally the upper frame 6
The bent portion 77 of 7 prevents the rotation. However, the heating roll 65 is connected to the upper frame 67.
When it is rotated together with the pressure roll 66 to open the gap, the bent portion 77 of the upper frame 67 no longer functions as a stopper, and thus the peeling member 61 on the pressure roll 66 side.
Since b is rotatable, it is possible to open a gap between the peeling action side 61c of the peeling member 61b and the roll surface of the pressure roll 66.

FIG. 7 is a side view showing a state in which the peeling member on the heating roll side is attached to the upper frame, and FIG. 8 is a perspective view thereof.

Japanese Unexamined Patent Publication No. 3-054587, Japanese Utility Model Publication No. 5
-4171, Japanese Patent Laid-Open No. 11-133776,
When the peeling member disclosed in Japanese Patent Laid-Open No. 2000-98791 has a peeling member having a metal substrate coated with an elastic layer, the peeling member is separated from the fixing member when the paper is jammed, and is separated from the fixing member. There is a problem that the jammed paper enters the space between the peeling side of the peeling member and the surface of the fixing member, and the elastic layer at the tip of the peeling member is destroyed. Further, means for pressing and fixing a part of the peeling member to the fixing member is used in order to regulate the relative positional relationship between the peeling member and the fixing member, but it is screwed to fix the peeling member. There is also a problem that the rotating torque at the time of applying is applied to the thin plate-shaped peeling member and the peeling member is deformed. Further, when the peeling member is deformed, the peeling member comes into contact with the fixing member to damage the surface of the fixing member, or a part of the peeling action side of the tip of the peeling member separates from the surface of the fixing member, which deteriorates the peeling performance. . These problems are not limited to fixing devices, and are problems that can generally occur when a peeling member is used.

In the above-described fixing device in the image forming apparatus of this embodiment, these problems are solved by the following method.

As shown in FIG. 8, the peeling member 61a on the heating roll 65 side is pressed against the heating roll 65 side with a constant load by the pressing member 72 having a spring function, and is pressed when peeling the recording medium. The stopper member receives pressure from the recording medium and moves the peeling member 61a in the direction opposite to the heating roll 65 side, and the stopper member prevents the peeling side from separating from the roll surface of the heating roll.

As shown in FIG. 7, the heating roll 65 and the peeling member 61a are attached to the upper frame 67, and the peeling member 61a has a peeling action side 61c for peeling the recording medium in the tangential direction of the roll surface of the heating roll 65. It is attached so as to be close to the object at an acute angle. The peeling member 61a is formed by the U-shaped groove member 71 composed of two U-shaped grooves, and thus the upper frame 67.
The U-groove member 71 is moved to the heating roll side 65 by being pressed with a constant load by an abutting spring 72 (not shown).
A third stud 80 is provided so that the peeling action side 61c stops at a position where a slight gap is opened between the la 1 and the roll surface of the heating roll 65.
0 is fitted in one U groove on the heating roll 65 side. Further, when the recording medium passes through the nip portion, the U-groove member 71 receives a force in the opposite direction to the heating roll 65 side, so that the gap between the peeling action side 61 c of the peeling member 61 a and the roll surface of the heating roll 65. A stopper 81 made of a screw screw is provided to prevent the screw from opening too much. The stopper 81 made of a screw screw is screwed to the upper frame 67, but when the movement of the U groove member 71 to the heating roll 65 side is stopped by the third stud 80, the stopper 81 made of a screw screw.
And a U-shaped groove member 71. Therefore, the stopper 81 consisting of a screw screw
Does not affect the peeling member 61a even if the screw is turned to attach and detach to the upper frame. A fourth stud 82 is fitted in the U groove member 71, and the fourth stud 82 is provided to prevent the U groove member from being displaced.

Here, the pressing member 72 is provided with a spring function, but both ends 2 in the roll axial direction of the peeling member.
When the pressing member 72 is provided at the location, a spring may be separately provided near the pressing member instead of the spring function. Further, it is preferable that the stopper 81 formed of a screw screw is arranged at a position where the moving distance is 1 mm or less when the peeling member 61a moves in the direction opposite to the heating roll 65 side.

As described above, since the peeling member 61a is pressed against the heating roll 65 side with a constant load by using the spring function, the twisting load due to the fastening and fixing such as screwing is eliminated, and thus the long peeling member 61a is removed. Deformation can be avoided. Also, when the paper is jammed, the peeling member 61a
Even if the sheet is pressed against the paper, the peeling action side 61c of the peeling member 61a is not separated from the roll surface of the heating roll 65 by a stopper 81 formed of a screw screw. It is possible to prevent the body layer from being damaged. Further, by providing the stopper 81 composed of a screw screw, the pressing load can be reduced, and if the pressing load is reduced, the peeling member 61a is less likely to be deformed.

The stopper 81 composed of the screw screw can be removed, and by removing it, the peeling action side 61c of the peeling member 61a can be separated from the roll surface of the heating roll 65.

FIG. 9 is a view showing a state of the U-groove member when performing maintenance such as replacement and cleaning of the heating roll.

In FIG. 9, the upper frame 67 and the heating roll 65 attached to the upper frame 67 are rotated about the first stud 70 rotatably connected, and the heating roll 65 and the pressure roll 66 are rotated. It is in a separated state. Then, the stopper 81 composed of a screw screw
Was removed, and the U-groove member 71 for attaching the peeling member 61a to the upper frame 67 was slid to the right in the figure, and the gap between the peeling action side 61c of the peeling member 61a and the roll surface of the heating roll 65 was opened larger than usual. In this state, the stopper 81 composed of a screw screw is screwed to the upper frame 67 again. The stopper 81 consisting of a screw screw is now the same U as the third stud 80.
The U-groove member 71 is prevented from sliding to the left in the drawing by being screwed into the groove, and the peeling action side 61c of the peeling member 61a is prevented.
Is prevented from hitting the roll surface of the heating roll 65.

In this state, the heating roll 65 can remove the heating roll 65 from the upper frame 67 without touching the peeling action side 61c of the peeling member 61a.

Here, the peeling member 61a is the U groove member 71.
Also, instead of using the stopper 81 composed of a screw screw, for example, the peeling member 61a may be configured to move on a bent slide rail.

Table 1 is a table showing the test results showing the moving distance until the peeling member slides and the stopper composed of the screw screw acts, and the state of the peeling side when the paper is jammed.

[0055]

[Table 1]

A fixing device was used as a test environment, and a heating roll of the fixing device was made of an aluminum core metal having an outer diameter of 43 mm and a wall thickness of 7.5 mm. The rubber layer is coated, and the surface of the silicone rubber layer is coated with 30 μm PFA (perfluoroalkyl vinyl ether copolymer resin). The pressure roll has an outer diameter of 46 mm and a wall thickness of 6 mm. The surface of the roll made of core metal was coated with a silicone rubber layer having a thickness of 2 mm and a rubber hardness of 24 degrees, and the surface of the silicone rubber layer was coated with 30 μm of PFA (perfluoroalkyl vinyl ether copolymer resin). It is a thing. The peeling member is a metal plate on which an elastic layer is formed and coated with a release layer, and the metal plate has a thickness of 0.2 mm.
The thick SUS spring material and the elastic layer are made of 0.2 mm thick fluorine rubber having a hardness of 60 degrees, and the release layer is made of 30 μm thick fluorine resin. In addition, the angle formed by the planes that are cut diagonally and intersect at an acute angle forming the peeling action side is 34 degrees,
The distance of the elastic layer from the peeling action side to the metal plate was 1 mm. This peeling member was placed at a position where the tip of the peeling member was 4 mm from the exit of the nip portion between the heating roll and the pressure roll and 0.5 mm from the surface of the heating roll. Then, the heating roll and the pressure roll are pressurized so that a nip width of 9 mm is formed, and the rotation speed of each roll is 220 mm /
s, the surface temperature of the heating roll was 170 ° C., and the surface temperature of the pressure roll was 140 ° C.

As an evaluation criterion, ⊚ does not cause damage to the tip of the peeling member when the paper having a basis weight of 105 g / m ² or less is jammed. ○ indicates slight damage to the tip of the peeling member when the paper having a weight of 105 g / m ² or less is jammed, and damage to the tip of the peeling member when the paper having a weight of 64 g / m ² or less is jammed. Absent. Δ indicates that the tip of the peeling member is damaged when the paper having a weight of 105 g / m ² or less is jammed, but the tip of the peeling member is slightly damaged when the paper having a weight of 64 g / m ² or less is jammed. . ×
Means a state in which the tip of the peeling member is damaged when a sheet having a basis weight of 64 g / m ² or less is jammed.

As is clear from Table 1, when the moving distance of the peeling member is 0.5 mm or less, the peeling action side of the tip of the peeling member is not damaged, and the moving distance of the peeling member is less than 1 mm. It was found that the peeling action edge at the tip of the peeling member was not damaged.

Therefore, when the peeling member is attached to the heating roll side, the peeling member is pressed against the roll side with a constant load by using the spring function, and the pressure in the opposite direction is restrained by the stopper. By using the configuration, the peeling member can be accurately positioned with respect to the surface of the heating roll, and the deformation of the peeling member can be avoided, so that the surface of the heating roll can be prevented from being scratched. Further, the fixing member can be easily replaced, and the maintainability can be improved.

FIG. 10 is a side view showing a state where the peeling member on the pressure roll side is attached to the lower frame.

Japanese Unexamined Patent Publication Nos. 11-133776 and 2000-98791 disclose methods of disposing a peeling member over the entire axial direction of a roll of a fixing device. Further, in order to prevent the peeling member from damaging the surface of the fixing member when the paper is jammed, a technique for preventing the peeling member from making point contact with the fixing member (Japanese Patent Laid-Open No. 1-277).
No. 272), a technique in which a stopper member is provided where the peeling member bites into the fixing member by a predetermined amount.
No. 88165) is disclosed. Further, a peeling member in which a thin metal substrate and an elastic member are integrally molded is also considered.

The peeling member on the pressure roll side of this embodiment is
The peeling side is used in contact with the roll surface. Unlike the heating roll side, the peeling member on the pressure roll side does not come into contact with the melted toner, so that there is no problem even if the peeling action side is brought into contact. Moreover, since the peeling action side can be brought into contact with the pressure roll surface, the relationship between the peeling action side of the peeling member and the pressure roll surface can be controlled by using a spring.

However, when a peeling member formed by integrally molding a thin metal substrate and an elastic member is used in contact, when a paper jam occurs, the elastic member of the peeling member deforms due to the pressure of the paper jammed. However, it may happen that the integrally molded metal substrate comes into contact with the pressure roll. In that case, if the amount of deformation of the elastic member is large, the elastic layer at the tip of the peeling member may be peeled off from the metal substrate, or the metal substrate may contact the pressure roll surface and the pressure roll surface may be damaged. Occurs.

Since the peeling member is a thin metal substrate integrally molded with the elastic member, it is impossible to contact the surface of the pressure roll except the tip of the peeling member, and the peeling member bites into the pressure roll. If the stopper member is provided at the position, the metal substrate may dig into the pressure roll depending on the position of the stopper, so that the problem cannot be solved. These are not limited to the fixing device, but are problems that can generally occur when the recording medium is peeled using the peeling member. The image forming apparatus of this embodiment solves these problems by the following method.

In FIG. 10, the heating roll and the upper frame (not shown) have already been rotated around the first stud for maintenance or the like, and are separated from the pressure roll. The pressure roll 66 includes the rotary shaft support member 6
The peeling member 61 b on the pressure roll 66 side is rotatably supported by 9, and is rotatably attached to the rotary shaft support member 69 by the second stud 73.

Since the peeling member 61b on the pressure roll 66 side is pulled downward in the drawing by a tension spring 67 (not shown), the peeling action side 61c at the tip of the peeling member 61b contacts the roll surface of the pressure roll 66. However, the stopper member 74 is provided on the rotary shaft support member 69, and the peeling action side 61
When c bites into the roll surface to some extent, the protrusion 6 of the peeling member
Since 1d abuts on the stopper member 74, the peeling action side 61c does not go deep into the roll surface.

FIG. 11 is a view showing the peeling member and the stopper member on the pressure roll side. As shown in FIG. 11, the pressure roll 66 is rotatably supported by a rotary shaft support member 69. The peeling member 61b on the pressure roll 66 side is rotatably supported by the rotation shaft support member 69 by the second stud 73, and is used for maintenance or the like.
The peeling action side 61c can be separated from the roll surface by rotating the peeling action side 61c. The peeling action side 61c at the tip of the peeling member 61b is in contact with the roll surface of the pressure roll 66, but the peeling member 61b is provided with a protrusion 61d, and the protrusion 61d is usually a rotary shaft support. Member 69
It is in close proximity to the stopper member 74 provided at the gap L.

Here, it is desirable that the second stud 73 and the stopper member 74 are provided on the same plane of the rotary shaft support member 69 in order to maintain the mutual positional relationship with high accuracy.
12 and 13 are enlarged views showing a state where the peeling action side 61c at the tip of the peeling member 61b is in contact with the roll surface of the pressure roll 66, and FIG. 12 shows that the protrusion 61d and the stopper member 74 are FIG. 13 shows a normal state in which the gap L is kept close to each other, and FIG. 13 shows a state in which the gap L is zero.

As shown in FIGS. 12 and 13, the gap L between the protrusion 61d of the peeling member 61b and the stopper member 74 is such that the elastic layer at the tip of the peeling member 61b contacts the pressure roll surface. , It is set so that it does not become zero even if it bites a little. However, even if the elastic material layer at the tip portion of the peeling member 61b bends due to a large amount of biting into the roll surface due to paper jam or the like, the protrusion 61d abuts on the stopper member 74, so that the metal substrate of the peeling member 61b becomes a roll surface. Immediately before contact, the gap L becomes zero, and the elastic layer at the tip of the peeling member 61b is set so as not to further dig into the roll surface.

Thus, even if the elastic layer of the peeling member 61b bites into the surface of the pressure roll 66 to some extent, the peeling member 6
Since the stopper member 74 is provided at a position where the metal substrate 1b does not bite into the surface of the pressure roll 66, the surface of the pressure roll is not damaged.

Table 2 is a table showing the test results of the state of the surface of the pressure roll and the state of the elastic layer at the tip of the peeling member when the paper is jammed due to the provision of the stopper member 74.

[0072]

[Table 2]

Since the test environment is the same as the evaluation environment shown in Table 1, it is omitted here.

As an evaluation criterion, ∘ indicates that the tip of the peeling member is not damaged in a paper jam condition of a paper having a weight of 105 g / m ² or less. Δ indicates that the tip of the peeling member is slightly damaged when the paper having a basis weight of 105 g / m ² or less is jammed. “X” means a state in which the PFA on the surface of the pressure roll is broken while the tip portion of the peeling member is broken when the paper having a basis weight of 105 g / m ² or less is jammed.

As is clear from Table 2, the stopper member 7
If No. 4 is not provided, the tip portion of the peeling member is damaged and the PFA on the surface of the pressure roll is also damaged. on the other hand,
By providing the stopper member, damage to the tip portion of the peeling member can be prevented even if the metal substrate bites into the pressure roll. However, the destruction of PFA on the surface of the pressure roll cannot be prevented. On the other hand, if the stopper member is provided at a position where the metal substrate does not bite into the pressure roll, it is possible to prevent damage to the tip of the peeling member and prevent damage to the surface of the pressure roll.

The above-described relationship between the fixing device and the peeling member has been described by using the fixing device including the heating roll and the pressure roll, but the fixing device is not limited to the one using the roll but the one using the belt. Can also be applied, and the same effect as in the case of rolls can be obtained. Further, the same effect as in the fixing device can be obtained by applying the peeling member not only to the fixing device but also to a working member of the recording medium that needs to peel the recording medium.

Next, the peeling member used in the image forming apparatus of the first embodiment of the present invention will be described.

FIG. 14 is a sectional view of a peeling member used in the image forming apparatus of the first embodiment of the present invention.

The peeling member shown in FIG. 14 is a metal substrate 100.
The elastic layer 101 is formed on the tip of the elastic layer 101.
The release layer 102 is coated on the surface of the
The second surface 102a has a rough surface.

The peeling member of this embodiment is the metal substrate 100.
An elastic layer is formed in the region of one end of the elastic layer, and minute irregularities are provided on the surface of the elastic layer. Further, the surface of the elastic layer and the surface of the metal substrate on which the elastic layer is not formed are coated with a release layer made of fluororubber, which has a good toner releasing property, and the surface of the release layer is also finely divided. The unevenness is provided. The rough surface of the release layer formed on the surface of the elastic layer is rougher than the rough surface of the release layer formed on the surface of the metal substrate.

When the surface is rough, point contact is made with the surface, and the contact area is reduced. The roughness of the rough surface of the tip of the peeling member, which comes closest to the high temperature fixing member and comes into contact with the relatively high temperature toner image that has just come out of the nip, is made rougher than other parts. Therefore, the area of point contact with the recording medium becomes smaller, and the fused toner image sticks to the peeling member, causing poor running,
This prevents the occurrence of so-called gloss unevenness, which is caused by uneven melting of the toner, which is caused by remelting of the toner in the already formed image. In the area other than the tip portion of the peeling member, the roughness is made smaller than that of the tip portion so that the recording medium having a toner image temperature lower than that of the tip portion can smoothly run.

Here, the size of the minute irregularities is such that the Rz value (the arithmetic mean value of ten-point average roughness defined in "JIS B 0601". The same applies hereinafter) is 3 μm or more and 20 μm or less.
The thickness is preferably less than m, more preferably 5 μm or more and less than 15 μm.

If the Rz value is less than 3 μm, the surface becomes close to a mirror surface, so that the contact area between the paper and the peeling member cannot be reduced, and the effect of providing minute irregularities on the surface cannot be obtained. On the other hand, when the Rz value is 20 μm or more, there occurs a problem that the leading end of the paper is caught in the unevenness on the surface of the peeling member and the leading end of the paper is bent.

When the Rz value is less than 5 μm, the surface of the peeling member comes into contact with the paper, so that the unevenness of the surface is worn in a short time and uneven glossiness, that is, so-called gloss unevenness is likely to occur. On the other hand, when the Rz value is 15 μm or more, when the paper is thin or the paper contains water, the leading end of the paper is easily caught by the peeling member.

Table 3 is a table showing the test results of the peeling performance when the roughness of the rough surface of the peeling member is changed.

[0086]

[Table 3]

As a test environment, the fixing device has a silicon rubber layer having a thickness of 3 mm and a rubber hardness of 24 degrees on a roll surface made of an aluminum core metal having an outer diameter of 43 mm and a thickness of 7.5 mm as a heating roll. , 30 on the surface of the silicone rubber layer
Using a roll having a PFA (perfluoroalkyl vinyl ether copolymer resin) coating layer of μm, the pressure roll has a roll surface of an outer diameter of 46 mm and a wall thickness of 6 mm made of an aluminum cored bar, and a wall thickness of 2 mm, A silicone rubber layer with a rubber hardness of 24 degrees is coated, and the surface of the silicone rubber layer is 30μ.
m coated with PFA (perfluoroalkyl vinyl ether copolymer resin) was used. The heating roll and the pressure roll are pressed so that a nip width of 9 mm is formed, the rotation speed of each roll is 220 mm / s, the surface temperature of each roll is 170 ° C., and the pressure roll surface temperature is 14
It was set to 0 ° C. The tip of the peeling member was arranged at a distance of 4 mm from the exit of the nip portion and 0.5 mm from the surface of the heating roll.

Table 3 shows the results of the peeling performance test under the test environment. Regarding the image quality, the evaluation criteria in Table 1 are ⊚, which means that no gross unevenness is visible when visually observed. ○ indicates a state in which gloss unevenness is visible but can be tolerated. Δ is a state in which gloss unevenness is visible when viewed, but is not a concern. X means that the gloss unevenness is noticeable when visually observed, and ⊚ means that there is no problem in terms of paper running property. ○ indicates that the paper can run. △ indicates that the paper is caught under special conditions such as when the paper is thin. X means a state in which a sheet is caught and a traveling failure occurs.

As is clear from Table 3, when the Rz is less than 3, the gloss unevenness is conspicuous, but when the Rz is 3 or more, the gloss unevenness is not a problem. However, as for the paper running property, if Rz is less than 15, there is no problem at all, but if it is 15 or more, it can run on plain paper, but if it is thin paper, it will be caught, and if it is 20 or more, even plain paper will be caught. .

Therefore, from Table 3, the size of the unevenness on the surface of the peeling member is generally such that the Rz value is 3 μm or more and 20 μm or less.
It is understood that the thickness may be less than 5 μm, and when thin paper is used, the thickness may be 5 μm or more and less than 15 μm.

As described above, since one surface of the peeling member is a rough surface, the recording medium to be peeled makes a point contact with the peeling member, and the area where the toner image formed on the recording medium contacts the peeling member. Is smaller, it is possible to prevent image damage due to the toner image after peeling being rubbed by the peeling member. Also, even if the peeling member is at a high temperature, the amount of heat conducted to the recording medium will be small, so the image immediately after fixing will have gloss unevenness, or the already fixed image on the back surface of the recording medium will be melted again and peeled off. It is possible to prevent the trouble caused by the recording medium sticking to the peeling member.

Here, the metal substrate 100 is made of SUS, the elastic layer 101 is formed by coating the SUS substrate with fluororubber, and the release layer 102 is formed on the surface of the elastic layer 101 and the metal substrate. It is formed by coating a fluororesin having good releasability. The release layer 102 may be coated with fluororubber instead of fluororesin.

As described above, since the metal substrate 100 is used, wavy deformation can be prevented by heat generated when a plastic sheet or the like is used as a peeling member, and water vapor generated from paper is rapidly and continuously generated near the metal. Condensation caused by being cooled down is prevented by molding an elastic body on the metal substrate 100 to reduce the thermal conductivity of the peeling member. Further, since the fluororesin having good releasability is coated on the surfaces of the elastic layer 101 and the metal substrate 100,
It is possible to prevent the toner from being offset or accumulated on the peeling member during the peeling.

Next, the rubber hardness of an elastic member such as fluororubber or fluororesin used for the elastic layer 101 will be described.

When the rubber hardness becomes low, the strength of the elastic body layer 101 becomes weak, so that a paper jam occurs when the paper is peeled from the heating roll, and the elastic body layer 101 is destroyed when pressure is applied to the paper in the accordion state. Will be done.

On the other hand, as the rubber hardness becomes higher, the elasticity becomes lower and the elastic layer 101 becomes hard. Therefore, when the elastic layer 101 comes into contact with the heating roll due to occurrence of jam or the like, the heating roll may be damaged.

Accordingly, the rubber hardness of the elastic member used for the elastic layer 101 is preferably in the range of 50 degrees or more and 90 degrees or less, and more preferably 60 degrees or 70 degrees.

Next, the entire peeling member of the present embodiment and the optimum range of dimensions of each member will be described.

FIG. 15 is a schematic diagram showing the relationship between the shape near the tip of the peeling member of this embodiment and the surface of the heating roll.

The peeling member shown in FIG. 15 is a metal substrate 100.
And the elastic layer 101 are shown, and the release layer 102 is omitted.

At the tip of the peeling member of this embodiment, the elastic layer 101 is obliquely cut, and the peeling action side 101a arranged close to the fixing member is formed by two surfaces intersecting at an acute angle θ. Since the leading edge of the paper is a blank area on which the toner image is not transferred, the gap between the leading edge of the paper and the surface of the heating roll is about the distance between the leading edge of the paper and the heating roll surface when the leading edge of the paper reaches the peeling member from the nip portion. Gap between the roll surface G
It is in a larger state than. Therefore, the leading end of the sheet moves along the diagonally cut surface of the peeling member as the heating roll rotates, and is not stressed. That is, by obliquely cutting the tip portion of the peeling member, it is possible to shift the side having the peeling action of the peeling member to the side intersecting at an acute angle. As a result,
The distance L from the heating roll surface to the peeling side is equal to the gap G between the heating roll surface and the peeling member, and the thickness of the peeling member can be apparently zero.

That is, even if the thickness of the peeling member is increased by coating the metal substrate with the elastic body, the thickness can be apparently zero as far as the peeling action is concerned, so that the peeling performance should be improved. You can

Here, it is desirable that the angle of the acute angle θ that intersects the two diagonally cut surfaces forming the peeling action side 101a closest to the fixing member is 25 degrees or more and 45 degrees or less. Below 25 degrees, the elastic layer 10
1 is easily broken, and if it exceeds 45 degrees, the side that performs the peeling action does not move to the peeling action side 101a that intersects the acute angle θ, and the degree of improvement in the peeling performance decreases.

The peeling member shown in FIG. 15 is a metal substrate 100.
And the elastic layer 101, the thickness of the metal substrate 100 is t2, the thickness of the elastic layer 101 is t1, and the thickness of the entire peeling member is t3. Further, the peeling action side 10 at the tip of the peeling member
The dimension of the elastic layer 101 between 1a and the metal substrate 100 is X, and the distance between the obliquely cut surface 101b and the end of the metal substrate 100 is Y.

First, the optimum ranges of the thickness t2 of the metal substrate 100, the thickness t1 of the elastic layer 101, and the thickness t3 of the entire peeling member will be described.

If the metal substrate 100 is too thin, the strength of the peeling member cannot be satisfied, and it is difficult to form it uniformly, so it is necessary to set the thickness to 0.1 mm or more. Also,
Similarly to the metal substrate 100, if the elastic layer 101 is too thin, it is deformed at the time of peeling or paper jam and cannot exert a peeling function, and it is difficult to uniformly mold the elastic layer 101.
It must be m or more.

On the other hand, if the total thickness t3 of the peeling member is too thick, for example, when it is installed at the recording medium exit side of the nip portion of the fixing device, the discharge path of the recording medium is narrowed, and a thick recording medium or curl is formed. Since the recording medium comes into contact with the peeling member and tends to cause paper jam or image damage in many cases.

Therefore, the peeling member is formed by changing the thickness of the metal substrate 100 and the elastic layer 101 so that the thickness of the metal substrate 100 and the elastic layer 101 is 0.1 mm or more. A test is performed using a peeling member, and the optimum range is determined based on the evaluation results of the occurrence of gloss unevenness, image damage, running performance, and the like.

Table 4 shows the thickness t2 of the metal substrate 100,
The elastic layer 101 is changed to 0.1 mm or more.
3 is a table showing the test results regarding the paper running property and the image damage of the peeling member formed by changing the thickness t1 thereof to 0.1 mm or more.

[0110]

[Table 4]

As the test environment, a fixing device including a fixing roll and a pressure roll was used. The outer diameter of the fixing roll is 4
A roll made of an aluminum cored bar having a thickness of 3 mm and a thickness of 7.5 mm has a silicon rubber layer having a thickness of 3 mm and a rubber hardness of 24 degrees, and 30 μm of PFA (perfluoroalkyl vinyl ether) is formed on the surface of the silicon rubber layer. Polymer resin) having a coating layer is used. The pressure roll has an outer diameter of 46 m.
m, 6 mm thick aluminum cored bar roll surface is coated with a 2 mm thick silicone rubber layer with a rubber hardness of 24 degrees, and the surface of the silicone rubber layer has a PFA (perfluoroalkyl vinyl ether co-weight) of 30 μm. The one coated with the united resin) was used. Fixing roll and pressure roll
Pressure was applied so that a nip width of 9 mm was formed, the rotation speed of the fixing roll was 220 mm / s, the surface temperature of each roll was 170 ° C., and the surface temperature of the pressure roll was 140 ° C. In addition, the peeling member has a tip portion from the exit of the nip portion 4
mm and a distance of 0.5 mm from the surface of the fixing roll.

As is clear from Table 4, the metal substrate 100
When the total thickness t3 of the elastic layer 101 was 0.4 mm or less, the running property of the paper and the image damage were good without any trouble. When the total thickness t3 of the metal substrate 100 and the elastic layer 101 was 0.6 mm or less, no problem occurred in the running property of plain paper, but image damage occurred in thick paper. Further, when the thickness t2 of the metal substrate 100 or the thickness t1 of the elastic layer 101 exceeds 0.6 mm, the paper discharge portion becomes narrow, so that a paper running defect occurs.

According to this performance test, the thickness t2 of the metal substrate 100 is set in the range of 0.1 mm or more and 0.5 mm or less, and the thickness t1 of the elastic layer 101 is set to 0.1 mm or more and 0.1 mm or more.
It can be seen that when the thickness is set to 5 mm or less and the total thickness t3 of the peeling member is combined to be 0.6 mm or less, generally good peeling performance can be obtained.

Next, the optimum range of the dimension X of the elastic layer at the tip of the peeling member will be described. For the peeling member, for example, the thickness t1 of the metal substrate 100 is 0.2 mm, and the elastic layer 101 is used.
Has a thickness t2 of 0.2 mm and is cut obliquely 101
The dimension X when the angle θ forming the acute angle of b is 34 degrees will be described.

When X is 0.5 mm or less, the distance Y between the obliquely cut surface 101b forming 34 degrees and the end of the metal substrate 100 becomes small, and the thickness of that portion of the elastic layer 101 becomes small. Since it becomes thin, the strength of the tip of the peeling member is insufficient, and the tip may be broken. On the other hand, 2
When the thickness is equal to or greater than mm, the strength of the elastic layer 101 and the strength of the peeling member become the same, and the tip of the peeling member may be broken by the force of the paper when the paper is jammed. Therefore, X
It can be seen that is required to be 0.5 mm or more and 2 mm or less.

As described above, the thickness t of the metal substrate 100 is
2 may be 0.1 mm or more and 0.5 mm or less, and the thickness t2 of the elastic body layer 101 may be 0.1 mm or more and 0.5 mm or less, and the obliquely cut acute angle θ may be 45 degrees or less. Since the thickness t1 of the metal substrate 100 is 0.2,
mm, the thickness t2 of the elastic layer 101 is 0.2 mm, and the angle θ forming an acute angle of the obliquely cut surface 101b is 34 degrees. And the optimum range of X for each θ can be obtained.

Next, a second embodiment of the present invention will be described.

The second embodiment is different from the first embodiment in the peeling member used in the image forming apparatus, but is common to the other members. Therefore, the difference will be described.

FIG. 16 is a sectional view of a peeling member used in the second embodiment of the present invention.

The peeling member used in this embodiment is different in that the elastic layer 101 is coated on the entire one surface of the metal substrate 100.

In the peeling member shown in FIG. 16, an elastic layer 101 made of fluororubber is formed on one entire surface of a metal substrate 100 made of SUS, and the surface of the elastic layer 101 is rough. Then, a fluororesin or fluororubber having releasability is coated on the elastic layer,
The release layer 102 is formed. The surface of the release layer 102 is rough.

Here, the release layer 102 can form a rough surface by coating along the minute unevenness of the elastic layer 1010 without providing the minute unevenness on its own.

By using the metal substrate as the base in this way, the wavy thermal deformation of the peeling member can be prevented, and the elastic layer is formed on the side of the metal plate which contacts the recording medium, and the side of the peeling member which contacts the recording medium. Since the thermal conductivity of the surface is small, it is possible to prevent dew condensation caused by the water vapor generated from the recording medium being rapidly and continuously cooled near the metal.
Further, it is possible to prevent the toner from adhering to the peeling member and the attached toner from being offset to another recording medium.

Further, since minute irregularities are provided on the entire surface of the peeling member that contacts the recording medium, it is possible to prevent uneven gloss and image damage, and the recording medium after peeling sticks to the peeling member. It is possible to avoid troubles caused by this. Next, a third embodiment of the present invention will be described.

The third embodiment is different from the first embodiment in the peeling member used in the image forming apparatus, but is common to the other members. Therefore, the difference will be described.

FIG. 17 is a sectional view of a peeling member used in the third embodiment of the present invention.

The peeling member used in this embodiment has the elastic layer 101 covering the entire one surface of the metal substrate 100, except that it does not have a release layer.

As shown in FIG. 17, the peeling member has an elastic layer 101 made of an elastic member having a good mold release property covering the entire one surface of the metal substrate 100, and a rough surface is formed on the surface of the elastic layer 101. Has been done.

Since the peeling member of this embodiment also uses the metal substrate, it is possible to prevent corrugated thermal deformation.
Further, since the elastic layer or the resin layer is formed on the side of the metal substrate that contacts the recording medium and the thermal conductivity of the surface of the peeling member that is in contact with the recording medium is small, the water vapor generated from the recording medium is near the metal. Therefore, it is possible to prevent dew condensation caused by rapid and continuous cooling. Further, since the elastic layer is made of a member having a good releasability, it is possible to prevent the toner from adhering to the peeling member and the adhered toner from being offset to another recording medium.

Further, since the minute unevenness is provided on the entire surface of the peeling member which is in contact with the recording medium, it is possible to prevent gloss unevenness and image damage, and the recording medium after peeling sticks to the peeling member. It is possible to avoid troubles caused by this. In the above-described first to third embodiments, the elastic layer is formed on the metal substrate,
Instead of the elastic layer, a resin layer formed of a heat resistant and abrasion resistant resin may be used. When a resin layer is used instead of the elastic layer, the rigidity is increased, so that the peeling member having high rigidity can be obtained. A peeling member using an elastic layer having a hardness of 60 to 70 degrees can be used for peeling a recording medium by contacting it with a fixing member or the like, but a peeling member using a resin layer has elasticity. However, it cannot be used in such a place because it damages the fixing member and the like, but is suitable for a place where strength is required.

Even in the peeling member using such a resin layer, it is preferable that minute unevenness is provided on the surface of the resin layer, and further minute unevenness is provided on the release layer coated on the resin layer. Furthermore, when the resin layer is present only in the region of the peeling member on the acting member side, the resin layer is provided with minute unevenness, or the release layer is coated on the entire surface of the peeling member in contact with the recording medium. By providing minute irregularities in the release layer, the rough surface of the acting member side area and the rough surface of the other area may have mutually different roughness. The peeling member is most likely to be affected by heat at the tip end, which is the closest to the fixing member, for example, the fixing member. Therefore, if the surface of the tip portion is rough, the contact area with the recording medium can be reduced, and as a result, the influence of heat can be suppressed.

Next, a fourth embodiment of the present invention will be described.

FIG. 18 is a schematic block diagram of a laser printer using an electrophotographic system which is a fourth embodiment of the image forming apparatus of the invention.

The laser printer according to the present embodiment has an input section for inputting image data, an image processing section for performing gradation correction using a look-up table for the input image data, and an image output section. An output terminal (hereinafter referred to as IOT) is provided, but the IOT is shown here.

The IOT of the laser printer shown in FIG.
A photoconductor drum 110 rotating in the direction of arrow A, and a scorotron charger 11 for charging the surface of the photoconductor drum 110.
2. Laser output for forming an electrostatic latent image on the photosensitive drum 110 by exposing the charged surface of the photosensitive drum 110 with exposure light modulated based on image data processed by an image processing unit (not shown). Part (hereinafter referred to as ROS) 11
3, a developing device 114 that develops the electrostatic latent image on the photoconductor 110 with toner to form a toner image on the photoconductor drum 110,
A transfer device 115 that transfers the toner image on the photoconductor drum 110 onto the paper P, a fixing device 116 that forms the nip portion 8 by the heating roll 116a and the pressure roll 116b to fix the transferred toner image onto the paper P, the paper. A paper tray 117 for accommodating P, a cleaner member 118 for cleaning the surface of the photoconductor drum 110, a static eliminator 119 for removing residual charges on the surface of the photoconductor drum 110, and a paper ejection stand for ejecting the paper P on which an image is formed. 120, paper discharge stand 120
A sheet conveying belt 121 that conveys sheets up to and a peeling member 122 that is arranged close to one fixing member of the fixing device 116 and that peels the sheet coming out from the nip portion from the fixing member.

In the laser printer of this embodiment, an image signal created by an external computer (not shown) or the like is input to an input section (not shown), and an image processing section (not shown).
However, this image signal is subjected to appropriate image processing such as gradation correction using a look-up table, and the processed image signal is output to the ROS 113. The ROS 113 modulates a laser beam, which is exposure light, based on the image signal sent from the image processing unit. The surface of the photosensitive drum 110 is uniformly charged by the scorotron charger 112. Then, the ROS 113 raster-irradiates the surface of the photosensitive drum 110 with the laser beam. Photoconductor drum 110
When the laser beam is applied to the surface of the photosensitive drum 11,
An electrostatic latent image corresponding to the image signal is formed on 0. Then, the electrostatic latent image on the photosensitive drum 110 is transferred to the developing device 11
It is developed with the toner in 4 to form a toner image. This toner image is conveyed to the transfer device 115 arranged facing the photoconductor drum 110 as the photoconductor drum 110 rotates in the direction of arrow A. On the other hand, paper tray 1
The paper P stored in 17 is transported by the paper transport belt 121 between the photoconductor drum 110 and the transfer device 115. Further, the transfer device 115 is configured to transfer the paper P that has been conveyed.
The toner image on the photosensitive drum 110 is transferred onto the surface. Further, the transferred toner image is fixed on the paper P by the heating roll 116a and the pressure roll 116b of the fixing device 116, and a desired image is formed on the paper P. In this case, since the toner image immediately after being fixed on the sheet is melted, it often comes out of the nip portion while sticking to the heating roll 116a.
Is peeled from the heating roll 116a by the peeling member 122 arranged in the vicinity of. The sheet P on which the image is formed is discharged to the sheet discharge tray 120 by the sheet conveying belt 121. After the transfer of the toner image onto the paper P is finished, the cleaner member 118 cleans the surface of the photoconductor drum 110, such as the residual toner adhered to the surface of the photoconductor drum 110.
The static eliminator 119 removes the residual charge, and one image forming operation is completed.

Here, the peeling member 122 is attached to the fixing device 116.
However, the peeling member 122 may be used when the paper is peeled from other acting members other than the fixing device 116 that come into contact with the paper being conveyed.

FIG. 19 is a diagram showing a fixing device and a peeling member used in the image forming apparatus of this embodiment.

The fixing device shown in FIG. 19 has a heat source 13 inside.
Heating roll 116a having 0 and rotating in the rotation direction A
And a pressure roll 116b having a heat source 130 therein, which rotates in the rotation direction B while forming the nip portion 131 by contacting the heating roll 116a,
The unfixed toner image 1 conveyed to the nip portion 131
The unfixed toner image 132 is fixed to the sheet P by heating and pressing the sheet P carrying the sheet 32.

Heating roll 116a and pressure roll 116b
Is a metal-made substrate roll 133 having a heat source 130 inside, an inner elastic layer 134 covered by the substrate roll 133, and a fluororesin having good releasability covered by the inner elastic layer 134. It has a surface layer 135 formed. The heating roll 116a and the pressure roll 116b form a nip portion 131 with an appropriate pressure between them by the elastic action of the inner elastic layer 134, and the nip portion 13 is formed.
While the sheet P passing through 1 is heated and pressed, the releasing action of the surface layer 135 prevents the unfixed toner image 132 of the sheet P from adhering to the surface of the heating roll 116a.

Further, the plate-shaped peeling member 122 is arranged so that the leading end thereof is closest to the heating roll 116a, and the sheet P that has passed through the nip 131 is heated by the peeling member 122. It is peeled off from 116a.

Here, in the image forming apparatus having the double-sided printing function, when printing on the back side, the sheet P having the toner images 6 fixed on both sides passes through the nip portion 131 again. At this time, the printed matter P may be wrapped around the pressure roll 116b side and come out from the nip portion 131, so that it may be printed on the downstream side of the nip portion 131 in the rotation direction B of the pressure roll 116b. Plate-shaped peeling member 1
22 may be arranged so as to be closest to the pressure roll 116b.

In the present embodiment, the fixing device in which the pair of fixing members are both rolls has been described, but instead of the rolls, a fixing member composed of a belt stretched over a plurality of rolls may be used, or A fixing member in which a belt is wound around a fixed pressure contact member may be used. Further, although the rolls each having a heat source inside have been described, one of the rolls may have a heat source, or the pressing member or the belt may have a heat source.

FIG. 20 is a sectional view of a peeling member used in the fourth embodiment of the present invention.

In FIG. 20, the peeling member is composed of a plate-shaped metal substrate 100 made of SUS, and one surface for peeling the recording medium is provided with minute unevenness.

By using the metal substrate as the base as described above, the wavy thermal deformation of the peeling member can be prevented. In addition, since minute unevenness is provided on the entire surface of the peeling member that is in contact with the recording medium, it is possible to prevent gloss unevenness and image damage, and to prevent problems caused by the recording medium after peeling sticking to the peeling member. Can be avoided.

In this embodiment, since the peeling member is the metal substrate 100 and the roll surface is easily scratched, when the recording medium is peeled from the recording medium acting member such as the fixing member in a non-contact manner or a jam occurs. Even if there is a trouble, it can be used, for example, when the tip of the peeling member is supported by a supporting member so as not to bite into the roll surface.

Next explained is the fifth embodiment of the invention.

The fifth embodiment is different from the fourth embodiment in the peeling member, but is the same in all other respects. Therefore, the peeling member will be described.

FIG. 21 is a sectional view of a peeling member used in the fifth embodiment of the present invention.

The peeling member shown in FIG. 21 comprises a plate-shaped metal substrate 100 and a release layer 102 coated on the surface of the metal substrate 100 in contact with the recording medium.
No. 02 has a rough surface. The metal substrate 100 is S
It is made of US, and the release layer 102 is formed on the SUS substrate by coating a fluororesin or fluororubber having releasability.

As described above, by using the metal plate as the base, it is possible to prevent the wave-like thermal deformation, and since the metal plate is coated with a releasing agent having a good releasing property, the toner may adhere to the metal plate or the like. Can be prevented from being offset to the recording medium. Further, since the surface of the release layer is provided with minute irregularities, it is possible to prevent gloss unevenness and image damage, and it is possible to avoid troubles due to the recording medium after peeling sticking to the peeling member.

[0153]

As described above, according to the image forming apparatus of the present invention, since minute unevenness is provided on the surface of the plate-like peeling member, surface contact is avoided, and image damage, uneven gloss, and image are prevented. It is possible to prevent defective running of the paper due to re-melting of the paper. In addition, wavy thermal deformation can be prevented by using a metal substrate as the base material, and by coating the elastic layer, the water vapor generated from the recording medium just emerging from the nip portion rapidly and continuously near the metal. It is also possible to prevent dew condensation caused by being cooled. Further, by coating the release layer, it is possible to prevent the toner from adhering to the peeling member and the attached toner from being offset to another recording medium. Also, the peeling performance can be improved by cutting the tip of the peeling member obliquely.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an IOT of a tandem type color printer showing an image forming apparatus to which a first embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a fixing device and a peeling member used in the first embodiment.

FIG. 3 is a side view showing a fixing device and a peeling member used in the first embodiment.

FIG. 4 is a transparent view of a side view of the entire fixing device to which the peeling member shown in FIG. 3 is attached.

FIG. 5 is a side view when the upper frame is rotated and the heating roll and the pressure roll are separated from each other for maintenance or the like.

FIG. 6 is a perspective view when the upper frame is rotated and the heating roll and the pressure roll are separated from each other for maintenance or the like.

FIG. 7 is a side view showing a state where a peeling member on the heating roll side is attached to the upper frame.

FIG. 8 is a perspective view showing a state where a peeling member on the heating roll side is attached to the upper frame.

FIG. 9 is a diagram showing a state of the U groove member at the time of maintenance such as replacement and cleaning of the heating roll.

FIG. 10 is a side view showing a state in which a peeling member on the pressure roll side is attached to a pressure roll rotation shaft support member.

FIG. 11 is a view showing a peeling member and a stopper member on the pressure roll side.

FIG. 12 is an enlarged view (normal state) showing a state where the peeling action side of the tip of the peeling member is in contact with the roll surface of the pressure roll.

FIG. 13 is an enlarged view (state in which the gap is zero) in which the peeling action side of the tip of the peeling member is in contact with the roll surface of the pressure roll.

FIG. 14 is a sectional view of a peeling member used in the first embodiment of the present invention.

FIG. 15 is a schematic diagram showing the relationship between the shape near the tip of the peeling member of the present embodiment and the heating roll surface.

FIG. 16 is a cross-sectional view of a peeling member used in the second embodiment of the present invention.

FIG. 17 is a cross-sectional view of a peeling member used in the third embodiment of the present invention.

FIG. 18 is a schematic configuration diagram of a laser printer using an electrophotographic system which is a fourth embodiment of the image forming apparatus of the invention.

FIG. 19 is a diagram showing a fixing device and a peeling member used in the image forming apparatus of the present embodiment.

FIG. 20 is a sectional view of a peeling member used in a fourth embodiment of the present invention.

FIG. 21 is a cross-sectional view of a peeling member used in the fifth embodiment of the present invention.

[Explanation of symbols]

50 Intermediate transfer belt 51 rolls 52,110 Photosensitive drum 53 Charger 54 exposure equipment 55,114 Developer 56 Primary transfer device 57 paper tray 58 recording medium 59 Secondary transfer device 60a a pair of fixing members 60b Nip part 61, 61a, 61b Separation member 61c, 101a peeling side 62 cleaner 63 Belt cleaner 65 heating roll 66 pressure roll 67 Upper frame 68 Lower frame 69 Rotating shaft support member 70 First Stud 71 U groove member 72 Pressing member 73 Second stud 74 Stopper member 75 Guide member 76 Extension spring 77 Bent part 80 Third Stud 81 stopper 82 Fourth stud 100 metal substrate 101 elastic layer 101b Diagonally cut surface 102 Release layer 113 ROS 115 transcription device 116 fixer 116a heating roll 116b Pressure roll 117 paper tray 118 cleaner member 119 Static eliminator 120 paper output tray 121 Paper transport belt 122 Peeling member 130 heat source 131 Nip part 132 unfixed toner image 133 Substrate roll 134 Inner elastic layer 135 surface layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keitaro Sonoguchi             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             Co., Ltd. Ebina Office F term (reference) 2H033 AA16 AA23 BA06 BA19 BA20                       BA21 BB01 BB28 BB35                 3F053 AA21 LA02 LA05 LB03

Claims (8)

[Claims] 1. An image forming apparatus for forming a toner image, and finally transferring and fixing the formed toner image on a recording medium to form an image of the fixed toner image on the recording medium. An action member arranged on the medium conveyance path to contact the recording medium being conveyed to exert a predetermined action on the recording medium, and one side thereof is arranged in contact with or close to the action member,
An image characterized by comprising a plate-shaped peeling member for peeling the recording medium being conveyed from the acting member, wherein the peeling member has a rough surface formed on the side contacting the recording medium being conveyed. Forming equipment. 2. A pair of fixing members for fixing a toner image on the recording medium by sandwiching and heating the recording medium being conveyed, wherein the acting member is one of the pair of fixing members. The image forming apparatus according to claim 1, wherein the image forming apparatus is the fixing member. 3. The peeling member includes a metal substrate, and a release layer which covers at least the surface of the metal substrate on the side where the peeling member contacts the recording medium and which prevents adhesion of the molten toner on the recording medium. The image forming apparatus according to claim 1, further comprising: a surface of the release layer formed to be a rough surface. 4. The peeling member according to claim 1, wherein the surface on the side in contact with the recording medium is a rough surface having an Rz value of 3 μm or more and less than 20 μm. Image forming apparatus. 5. The image forming apparatus according to claim 3, wherein the peeling member has an elastic layer or a resin layer between the metal substrate and the release layer. 6. The image forming apparatus according to claim 5, wherein the elastic layer or the resin layer of the peeling member has a rough surface on the surface in contact with the release layer. 7. The resin layer is formed of a heat-resistant and abrasion-resistant resin.
The image forming apparatus described. 8. The release member has the elastic layer or the resin layer only in a region of the metal substrate on a side where the release member comes in contact with or comes close to the acting member. The layer surface is characterized in that the surface roughness of the region of the release layer formed on the elastic layer or the resin layer and the region excluding the region are different from each other. 5. The image forming apparatus according to item 5.