JP2010117502A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that facilitates maintenance and replacement of a polishing member that polishes an intermediate transfer belt. <P>SOLUTION: The image forming apparatus has: an image carrier 2, a charging means 3, an exposure means 7, and a developing means 4, at least one of which can be detachably attached to the body of the image forming apparatus as a process unit 1Y. The image forming apparatus includes: an intermediate transfer belt 10 performing a circumference run and arranged opposed to the image carrier 2; a primary transfer means 11Y for primarily transferring a toner image formed on the image carrier 2 onto the intermediate transfer belt 10; and a secondary transfer means 12 for secondarily transferring the toner image on the intermediate transfer belt 10 onto a recording medium. The polishing member 23, which polishes the intermediate transfer belt 10 in contact with the surface of this belt 10, is disposed in the process unit 1Y. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a device having a composite function of these.

  As an image forming apparatus using an electrophotographic image forming process such as a copying machine, a facsimile machine, a printer, etc., toner images of different colors carried on the surfaces of a plurality of photosensitive members are primarily transferred to an intermediate transfer belt, and the intermediate 2. Description of the Related Art An indirect transfer type image forming apparatus is known in which a toner image transferred to a transfer body is secondarily transferred collectively to a recording medium such as paper.

  As shown in FIG. 8, this type of image forming apparatus includes a plurality of process units 1Y, 1C, 1M, 1Bk in which process means such as a photoconductor, a charging device, and a developing device are housed in a case, and the photoconductor. An exposure device 7 for exposing the surface, an intermediate transfer belt 10, a plurality of primary transfer rollers 11Y, 11C, 11M, and 11Bk for transferring an image formed on the surface of the photosensitive member to the intermediate transfer belt 10, and an intermediate The image forming apparatus includes a secondary transfer roller 12 for transferring an image on the transfer belt 10 to a recording medium such as transfer paper, a fixing device 16 for fixing the image on the recording medium, a recording medium accommodating portion 13 and the like.

  When image formation is performed by the image forming apparatus shown in FIG. 8, the surface of the photosensitive member is charged by the charging device in each of the process units 1Y, 1C, 1M, and 1Bk, and the charged surface of the photosensitive member is exposed by the exposure device 7. Thus, an electrostatic latent image is formed. Toner is transferred from the developing device to the portion of the electrostatic latent image on the photoreceptor to form toner images of each color. Thereafter, the primary transfer rollers 11Y, 11C, 11M, and 11Bk primarily transfer the toner image formed on the surface of each photoconductor so as to overlap the intermediate transfer belt 10, and then the secondary transfer roller 12 performs the intermediate transfer. The toner image on the belt 10 is secondarily transferred to a recording medium sent from the recording medium storage unit 13. The recording medium to which the toner image has been transferred is heated and pressurized when passing through the fixing device 16 to fix the toner image, and is discharged to a stock section provided at the upper portion of the image forming apparatus. Further, the toner remaining on the surface of the intermediate transfer belt 10 after the secondary transfer is removed by a belt cleaning device 21 disposed on the intermediate transfer belt 10.

  In recent years, especially in the low-end printer field where costs are reduced, inexpensive members that have not been used in conventional image forming apparatuses tend to be used in order to simplify various functional components and integrate functions. This tendency is the same for the transfer device. By using an inexpensive member as a constituent member of the transfer device, there is a problem that the surface of the intermediate transfer belt is easily damaged. If the surface of the intermediate transfer belt is scratched and the surface roughness becomes too rough, the belt cleaning property is lowered, so that a good transfer cannot be performed and the image quality may be lowered.

Therefore, for example, the image forming apparatus described in Patent Document 1 includes a polishing device that polishes the surface of the intermediate transfer belt, and the surface roughness of the intermediate transfer belt is obtained by polishing the surface of the intermediate transfer belt with this polishing device. Is maintained at a predetermined value.
JP 2006-235052 A

  The polishing apparatus described in Patent Document 1 is not configured to be easily taken out of the image forming apparatus. For this reason, it has been difficult to perform maintenance work such as cleaning or replacement work with a new one when the polishing member provided in the polishing apparatus becomes dirty or worn.

  In view of such circumstances, an object of the present invention is to provide an image forming apparatus that can easily perform maintenance work, replacement work, and the like of a polishing member for polishing an intermediate transfer belt.

  According to a first aspect of the present invention, there is provided an image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the surface of the image carrier to form an electrostatic latent image, and the image carrier. An image forming apparatus comprising developing means for forming toner images by supplying toner to the electrostatic latent image formed on the surface of the image forming apparatus, wherein at least one of these is detachably attached to the image forming apparatus main body as a process unit An intermediate transfer belt that runs around and is disposed opposite to the image carrier, and a primary transfer unit that primarily transfers a toner image formed on the image carrier onto the intermediate transfer belt; In an image forming apparatus comprising secondary transfer means for secondary transfer of a toner image on the intermediate transfer belt to a recording medium, a polishing member that contacts the surface of the intermediate transfer belt and polishes the intermediate transfer belt, Process In which it is disposed the unit.

  When the intermediate transfer belt travels, the polishing member is brought into sliding contact with the surface of the intermediate transfer belt, whereby the surface of the intermediate transfer belt is polished and scratches and the like attached to the surface of the intermediate transfer belt can be removed. Thus, the surface roughness of the intermediate transfer belt can be maintained at a predetermined value, and good image formation can be maintained.

  Further, since the polishing member is disposed in the process unit, the process unit and the polishing member can be attached to and detached from the image forming apparatus main body together. As a result, maintenance work and replacement work of the polishing member can be easily performed, and the polishing effect can be maintained satisfactorily.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the process unit is attached to or detached from the main body of the image forming apparatus, the polishing member is applied in a direction intersecting the surface of the intermediate transfer belt. It is configured to be in contact with or separated from.

  When attaching / detaching the process unit to / from the image forming apparatus main body, the polishing member is configured to abut / separate in a direction intersecting the surface of the intermediate transfer belt so that the intermediate transfer belt is not damaged. It becomes possible to attach and detach the polishing member.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, after the intermediate transfer belt passes through a position where the secondary transfer is performed by the secondary transfer unit, the primary transfer unit performs the primary transfer. The polishing member is brought into contact with the surface of the intermediate transfer belt in the traveling path up to the position where the toner is transferred.

  This prevents the abrasive member from coming into contact with the surface of the intermediate transfer belt carrying the image, so that the image on the intermediate transfer belt is not disturbed by the abrasive member and good image formation can be performed. it can.

  According to a fourth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to third aspects, further comprising a belt cleaning unit that cleans a surface of the intermediate transfer belt, wherein the intermediate transfer is performed. The polishing member is brought into contact with the surface of the intermediate transfer belt in a traveling path after the belt passes the position where the cleaning is performed by the belt cleaning unit and before reaching the position where the primary transfer is performed by the primary transfer unit. It has been made.

  As a result, the polishing member comes into contact with the intermediate transfer belt after being cleaned by the belt cleaning means, so that the toner can be prevented from adhering to the polishing member, and the polishing effect of the polishing member can be improved. Can be maintained.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the length in the running direction of the intermediate transfer belt on the contact surface of the polishing member that contacts the intermediate transfer belt is set. X is set such that X ≧ Y, where X is Y and the thickness of the polishing member in the direction orthogonal to the contact surface is Y.

  As a result, the polishing member is unlikely to fall on the intermediate transfer belt, and the posture of the polishing member is stabilized. For this reason, the contact state between the polishing member and the intermediate transfer belt can be favorably maintained.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, between the end surface of the polishing member on the side where the intermediate transfer belt enters and the surface of the intermediate transfer belt. The abutting angle formed in the above is set to be 90 ° or less.

  As a result, deformation and entrainment of the polishing member due to contact with the intermediate transfer belt can be prevented, and the polishing effect can be stably exhibited.

  A seventh aspect of the present invention is the image forming apparatus according to any one of the first to sixth aspects, wherein the process unit includes an image carrier unit having at least the image carrier, and at least the developing unit. The image carrier unit and the development unit are configured to be separable, and the polishing member is disposed in the image carrier unit or the development unit.

  Also in the process unit configured as described above, by removing the image carrier unit or developing unit in which the polishing member is disposed from the image forming apparatus, maintenance work and replacement work of the polishing member can be easily performed as described above. It is possible.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the polishing member is made of a solid material.

  A solid material can be applied as the polishing member.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the polishing member is formed of a foamed member.

  Since the polishing member is made of a foamed member, the polishing member can be manufactured at low cost.

  A tenth aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, wherein the polishing member is made of a melamine resin.

  By constituting the polishing member with melamine resin, a high polishing effect can be exhibited.

  The invention according to claim 11 is the image forming apparatus according to any one of claims 1 to 10, wherein the polishing member is formed in a roller shape, and the roller-shaped polishing member is configured to be rotatable. .

  The polishing effect can be improved by bringing the polishing member into sliding contact with the intermediate transfer belt while rotating. In addition, the abrasive member is brought into sliding contact with the intermediate transfer belt, and then the abrasive member is rotated when the abrasive member is worn. Can be made. Thereby, it is also possible to maintain a favorable polishing effect.

  According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the intermediate transfer belt is configured to be able to travel in a direction opposite to a traveling direction when image formation is performed. is there.

  When foreign matter or the like is present between the polishing member and the intermediate transfer belt, it is possible to discharge the foreign matter or the like from between the polishing member and the intermediate transfer belt by running the intermediate transfer belt in the reverse direction. .

  According to the image forming apparatus of the present invention, since the polishing member is disposed in the process unit, the process unit and the polishing member can be attached to and detached from the image forming apparatus main body together. As a result, maintenance work and replacement work of the polishing member can be easily performed, and the polishing effect can be maintained satisfactorily.

  FIG. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus according to the present invention. The image forming apparatus of the present invention shown in FIG. 1 includes four process units 1Y, 1C, 1M, and 1Bk. Each of the process units 1Y, 1C, 1M, and 1Bk is configured to be detachable from the image forming apparatus main body 100.

  The process units 1Y, 1C, 1M, and 1Bk have the same configuration except that they contain toners of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image. Therefore, the configuration of one process unit 1Y will be described as an example.

  The process unit 1Y includes a photosensitive member 2 as an electrostatic latent image carrier, a charging roller 3 as a charging unit that charges the surface of the photosensitive member 2, and a developing unit that forms a toner image on the surface of the photosensitive member 2. A developing device 4 and a photosensitive member cleaning blade 5 as a cleaning means for cleaning the surface of the photosensitive member 2 are provided.

  Above each of the process units 1Y, 1C, 1M, and 1Bk, an exposure device 7 is disposed as an exposure unit that exposes the surface of the photoreceptor 2. An intermediate transfer unit 6 is disposed below each process unit 1Y, 1C, 1M, 1Bk. The intermediate transfer unit 6 has an intermediate transfer belt 10 constituted by an endless belt. The intermediate transfer belt 10 is stretched around a driving roller 8 and a driven roller 9 and is configured to be able to run around in the direction of the arrow in the figure. The driven roller 9 functions as a tension roller for applying a predetermined tension to the intermediate transfer belt 10.

  On the inner peripheral surface of the intermediate transfer belt 10, four primary transfer rollers 11Y, 11C, 11M, and 11Bk as primary transfer units are disposed to face the four photoconductors 2. The four photoconductors 2 are in pressure contact with the outer peripheral surface of the intermediate transfer belt 10, and a primary transfer nip is formed at each pressure contact portion.

  A secondary transfer roller 12 as a secondary transfer unit is disposed at a position facing the driving roller 8 that stretches the intermediate transfer belt 10. The secondary transfer roller 12 is in pressure contact with the outer peripheral surface of the intermediate transfer belt 10 and forms a secondary transfer nip at the pressure contact portion.

  The intermediate transfer unit 6 includes a belt cleaning device (belt cleaning unit) 21 for cleaning the surface of the intermediate transfer belt 10. A waste toner container 22 for storing waste toner is disposed below the intermediate transfer unit 6. A waste toner transfer hose (not shown) extending from the belt cleaning device 21 is connected to the entrance of the waste toner container 22.

  A recording medium storage unit 13 that stores a recording medium S such as paper or an OHP sheet is disposed below the image forming apparatus main body 100. The recording medium accommodating portion 13 is provided with a supply roller 14 for carrying out the recording medium S and the like.

  In the image forming apparatus main body 100, a conveyance path R for guiding the recording medium S upward from the recording medium accommodating portion 13 is disposed. A pair of registration rollers 15a and 15b are disposed on the upstream side (downward in the drawing) of the transport path R with respect to the secondary transfer nip formed by the drive roller 8 and the secondary transfer roller 12. In addition, the fixing device 16 is disposed downstream of the secondary transfer nip in the conveyance direction of the conveyance path R (upward in the drawing). The fixing device 16 includes a heating roller 17 and a pressure roller 18. The heating roller 17 and the pressure roller 18 are in pressure contact with each other, and a fixing nip is formed at the pressure contact portion.

  A pair of discharge rollers 19 a and 19 b are disposed at the downstream end of the transport path R in the transport direction. In addition, a stock unit 20 on which the recording medium S is loaded is formed with the upper surface of the image forming apparatus main body 100 being recessed inward.

The basic operation of the image forming apparatus will be described below with reference to FIG.
In the process unit 1Y, the photosensitive member 2 is rotated in the direction of the arrow in the figure, and the surface of the photosensitive member 2 is charged to a uniform high potential by the charging roller 3. Next, a laser beam is irradiated from the exposure device 7 to the surface of the photoconductor 2 based on the image data, and the potential of the irradiated portion is lowered to form an electrostatic latent image. The toner charged by the developing device 4 is electrostatically transferred to the portion of the electrostatic latent image formed on the surface of the photoreceptor 2 to form a yellow toner image (visualization).

  The primary transfer roller 11Y is applied with a constant voltage or a constant current controlled voltage having a polarity opposite to the charging polarity of the toner. As a result, a transfer electric field is formed in the primary transfer nip between the primary transfer roller 11Y and the photoreceptor 2. Then, in the primary transfer nip, the toner image on the rotating photoconductor 2 is primarily transferred to the intermediate transfer belt 10 running in the direction of the arrow in the figure.

  In each of the other process units 1C, 1M, and 1Bk, a toner image is similarly formed on the photoreceptor 2, and the four color toner images are primarily transferred to the intermediate transfer belt 10 so as to overlap each other.

  Further, the surface of the photoreceptor 2 after the primary transfer process is cleaned by the photoreceptor cleaning blade 5 to remove residual toner. Further, the residual charge remaining on the surface of the photoreceptor 2 is neutralized by a neutralizing lamp (not shown).

  On the other hand, the recording medium S accommodated in the recording medium accommodating portion 13 is sent out to the conveyance path R by rotating the supply roller 14. The sent recording medium S is temporarily stopped by the registration rollers 15a and 15b.

  Further, a voltage having a polarity opposite to the charging polarity of the toner is applied to the secondary transfer roller 12 to form a transfer electric field in the secondary transfer nip. Alternatively, a similar transfer electric field may be formed by applying a voltage having the same polarity as the charging polarity of the toner to the driving roller 8 facing the secondary transfer roller 12. Thereafter, the driving of the registration rollers 15a and 15b is resumed, and the recording medium S is sent to the secondary transfer nip in synchronism with the toner image on the intermediate transfer belt 10. Then, the toner image on the intermediate transfer belt 10 is secondarily transferred collectively onto the recording medium S by a transfer electric field formed in the secondary transfer nip. Further, after the secondary transfer, the toner remaining on the surface of the intermediate transfer belt 10 is removed by the belt cleaning device 21, and the removed toner is collected in the waste toner container 22.

  The recording medium S to which the toner image has been transferred is conveyed to the fixing device 16. The recording medium S sent to the fixing device 16 is sandwiched between the heating roller 17 and the pressure roller 18 and heated and pressurized, and the toner image is fixed on the recording medium S. Thereafter, the recording medium S is discharged to the stock unit 20 by the discharge rollers 19a and 19b.

FIG. 2 is a schematic diagram of the four process units 1Y, 1C, 1M, and 1Bk and the intermediate transfer unit 6.
As shown in FIG. 2, the process units 1 </ b> Y, 1 </ b> C, 1 </ b> M, and 1 </ b> Bk for each color are arranged side by side in the running direction of the intermediate transfer belt 10. Of the four process units 1Y, 1C, 1M, and 1Bk arranged side by side on the intermediate transfer belt 10, a process of first transferring an image onto the most upstream side in the running direction of the intermediate transfer belt 10, that is, the intermediate transfer belt 10. In the unit 1Y, a polishing member 23 for polishing the surface of the intermediate transfer belt 10 is disposed. The polishing member 23 is attached to the surface of the exterior case of the process unit 1Y facing the intermediate transfer belt 10, and the polishing member 23 is attached to the main body of the image forming apparatus while the process unit 1Y is mounted on the main body of the intermediate transfer belt 10. It comes into contact with the surface (outer peripheral surface).

  In addition, the polishing member 23 is upstream of the intermediate transfer belt 10 in the transport direction from the primary transfer roller 11Y (most upstream side) facing the photoreceptor 2 of the upstreammost process unit 1Y, and is secondary transfer. The intermediate transfer belt 10 is disposed downstream of the roller 12 in the conveyance direction. In other words, after the intermediate transfer belt 10 passes the position (secondary transfer nip) N2 where the secondary transfer is performed by the secondary transfer roller 12, the position (primary transfer nip) N1 where the primary transfer is performed by the primary transfer roller 11Y. The polishing member 23 is configured to come into contact with the surface of the intermediate transfer belt 10 in the travel path up to.

  Further, the polishing member 23 is disposed downstream of the belt cleaning device 21 in the transport direction of the intermediate transfer belt 10. In other words, after the intermediate transfer belt 10 has passed through the position N3 where the cleaning is performed by the belt cleaning device 21, it reaches the position (primary transfer nip) N1 where the primary transfer is performed by the primary transfer roller 11Y (on the most upstream side). The polishing member 23 is configured to come into contact with the surface of the intermediate transfer belt 10 in the travel route up to the above.

  The polishing member 23 is a block-like solid body (cuboid) disposed in a longitudinal shape over the width direction of the intermediate transfer belt 10. The material of the polishing member 23 can be arbitrarily selected from known polishing members and can be applied, but can be manufactured at low cost by configuring the polishing member 23 with a foamed member. Further, in order to obtain a high polishing effect, it is preferable that the polishing member 23 is made of melamine resin.

FIG. 3 is an enlarged view of the lower part of the process unit 1Y.
As shown in FIG. 3, the length in the running direction of the intermediate transfer belt 10 at the contact surface 23a that contacts the intermediate transfer belt 10 of the polishing member 23 is X, and the polishing member 23 in the direction orthogonal to the contact surface 23a. It is preferable to set so that X ≧ Y, where Y is the thickness.

  Further, as shown in FIG. 3, the contact angle θ formed between the end surface 23b of the polishing member 23 on the side where the intermediate transfer belt 10 enters (upstream side in the transport direction) and the surface of the intermediate transfer belt 23 is set. , 90 ° or less is desirable.

FIG. 4 is a diagram showing how the process unit 1Y is attached to and detached from the image forming apparatus main body.
As shown in FIG. 4, when the process unit 1 </ b> Y is attached to and detached from the image forming apparatus main body, the polishing member 23 is configured to contact and separate in a direction intersecting the surface of the intermediate transfer belt 10.

FIG. 5 is a view showing another embodiment of the polishing member 23.
The polishing member 23 shown in FIG. 5 is formed in a roller shape. Further, the roller-shaped polishing member 23 is configured to be rotatable by a rotation driving means (not shown). Other configurations are the same as those in the above embodiment, and thus the description thereof is omitted.

FIG. 6 is a diagram showing another embodiment of the process unit 1Y.
The process unit 1Y shown in FIG. 6 includes an image carrier unit 24 having at least the photosensitive member 2 and a developing unit 25 having at least the developing device 4. The image carrier unit 24 and the developing device 25 are separable from each other. It is composed of. In this embodiment, the image carrier unit 24 includes a charging roller 3 and a cleaning blade 5 in addition to the photoreceptor 2. In the process unit 1 </ b> Y configured as described above, the polishing member 23 for polishing the intermediate transfer belt 10 is disposed in the image carrier unit 24. Further, the polishing member 23 can be disposed in the developing device 25.

  Further, as shown in FIG. 7, in each of the above embodiments of the present invention, the intermediate transfer belt 10 is configured to be able to travel in the direction opposite to the traveling direction when performing image formation (the direction of the arrow in FIG. 7). Also good.

  In the image forming apparatus of the present invention having the polishing member 23, when image formation is performed, the polishing member 23 is brought into sliding contact with the surface of the traveling intermediate transfer belt 10. Thereby, the surface of the intermediate transfer belt 10 is polished, and scratches and the like attached to the surface of the intermediate transfer belt 10 can be removed. Accordingly, the surface roughness of the intermediate transfer belt 10 can be maintained at a predetermined value, and good image formation can be maintained.

  As described above, the polishing member 23 is in contact with the surface of the intermediate transfer belt 10 in the traveling path from when the intermediate transfer belt 10 passes through the secondary transfer nip N2 to before reaching the primary transfer nip N1. That is, the polishing member 23 is configured not to contact the surface of the intermediate transfer belt 10 in a state where an image is carried. Thereby, the image on the intermediate transfer belt 10 is not disturbed by the polishing member 23, and good image formation can be performed.

  In addition, the polishing member 23 is in contact with the surface of the intermediate transfer belt 10 in the traveling path from the intermediate transfer belt 10 passing through the position N3 where the cleaning is performed by the belt cleaning device 21 to the primary transfer nip N1. . That is, since the polishing member 23 contacts the intermediate transfer belt 10 after being cleaned by the belt cleaning device 21, it is possible to prevent toner from adhering to the polishing member 23. Thereby, the polishing effect of the polishing member 23 is maintained satisfactorily.

  Further, the length X in the running direction of the intermediate transfer belt 10 on the contact surface 23a of the polishing member 23 is equal to or greater than the thickness Y of the polishing member 23 in the direction orthogonal to the contact surface 23a (X ≧ Y). Since the setting is made, the polishing member 23 is unlikely to fall on the intermediate transfer belt 10, and the posture of the polishing member 23 is stabilized. As a result, the contact state between the polishing member 23 and the intermediate transfer belt 10 can be maintained satisfactorily.

  Further, the contact angle θ formed between the end surface 23b of the polishing member 23 on the side on which the intermediate transfer belt 10 enters (upstream side in the transport direction) and the surface of the intermediate transfer belt 23 is set to 90 ° or less. Therefore, the deformation and entrainment of the polishing member 23 due to contact with the intermediate transfer belt 10 can be prevented, and the polishing effect can be stably exhibited.

  In the case where the polishing member 23 is formed in a roller shape as in the embodiment shown in FIG. 5, when performing image formation, the speed is mutually in the same direction (trailing direction) as the intermediate transfer belt 10 running on the polishing member 23. Rotate with difference. Accordingly, the polishing member 23 is brought into sliding contact with the surface of the intermediate transfer belt 10, and the surface of the intermediate transfer belt 10 can be polished. Further, the intermediate transfer belt 10 may be polished by rotating the polishing member 23 in the direction opposite to the traveling direction of the intermediate transfer belt 10 (counter direction). Thus, the polishing effect can be improved by rotating the polishing member 23.

  Further, it is also possible to perform polishing by sliding on the traveling intermediate transfer belt 10 while the roller-shaped polishing member 23 is stationary without rotating. In this case, by rotating the polishing member 23 when the polishing member 23 is worn, a new surface of the polishing member 23 that is not worn can be brought into contact with the intermediate transfer belt 10, and the polishing effect is maintained well. It is possible.

  Further, in the embodiment in which the intermediate transfer belt 10 is configured to be able to travel in the direction opposite to the traveling direction when performing image formation (the direction of the arrow in FIG. 7), the intermediate transfer belt 10 is interposed between the polishing member 23 and the intermediate transfer belt 10. When foreign matter or the like is present, it is possible to discharge the foreign matter or the like from between the polishing member 23 and the intermediate transfer belt 10 by running the intermediate transfer belt 10 in the reverse direction. Further, it is possible to remove the foreign matter or the like by running the intermediate transfer belt 10 in the reverse direction and sending the foreign matter or the like on the intermediate transfer belt 10 to the belt cleaning device 21 or the like.

  As described above, in the image forming apparatus of the present invention, the polishing member 23 is disposed in the process unit 1Y. For this reason, as shown in FIG. 4, the process unit 1Y and the polishing member 23 can be attached to and detached from the image forming apparatus main body together. As a result, maintenance work and replacement work of the polishing member 23 can be easily performed, and the polishing effect can be maintained satisfactorily.

  Moreover, in the above-described embodiment, the polishing member 23 is configured to abut and separate in a direction intersecting the surface of the intermediate transfer belt 10 when the process unit 1Y is attached or detached. As a result, the polishing member 23 can be attached and detached without damaging the intermediate transfer belt 10.

  Further, as shown in FIG. 6, even when the process unit 1Y has an image carrier unit 24 and a development unit 25 that are separable from each other, the image carrier unit 24 provided with the polishing member 23 is used as the image forming apparatus. It is possible to easily perform maintenance work or replacement work of the polishing member 23 in the same manner as described above.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention. In FIG. 1, the configuration of the present invention is applied to a so-called tandem type color image forming apparatus including a plurality of process units. However, a plurality of developing devices are provided around one photosensitive member, and these developing devices are provided. Thus, the present invention can also be applied to a so-called one-drum type color image forming apparatus that transfers a composite toner image of each color formed on a photoconductor to a recording medium via an intermediate transfer belt.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of a process unit and an intermediate transfer unit. It is the figure which expanded the lower part of the said process unit. It is a figure which shows the attachment or detachment operation | movement of the said process unit. It is a figure which shows other embodiment of an abrasive member. It is a figure which shows other embodiment of the said process unit. FIG. 4 is a diagram illustrating a state in which an intermediate transfer belt is reversely fed. It is the schematic which shows the whole structure of the conventional image forming apparatus.

Explanation of symbols

1Y process unit 2 photoconductor 3 charging roller 4 developing device 7 exposure device 10 intermediate transfer belt 11Y primary transfer roller 12 secondary transfer roller 21 belt cleaning device 23 polishing member 23a abutting surface 23b end surface 24 image carrier unit 25 developing unit 100 Image forming apparatus main body X Length of the intermediate transfer belt in the running direction at the contact surface Y Thickness of the polishing member in a direction orthogonal to the contact surface θ Contact angle

Claims (12)

An image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the surface of the image carrier to form an electrostatic latent image, and a static image formed on the surface of the image carrier. An image forming apparatus including a developing unit that supplies toner to an electrostatic latent image to form a toner image, and at least one of them is configured to be detachable from a main body of the image forming apparatus as a process unit. And an intermediate transfer belt disposed opposite to the image carrier, primary transfer means for primarily transferring a toner image formed on the image carrier onto the intermediate transfer belt, and toner on the intermediate transfer belt In an image forming apparatus comprising secondary transfer means for secondary transfer of an image to a recording medium,
An image forming apparatus comprising: a polishing member disposed in the process unit for contacting the surface of the intermediate transfer belt to polish the intermediate transfer belt.   2. The image forming apparatus according to claim 1, wherein when the process unit is attached to and detached from the image forming apparatus main body, the polishing member is configured to contact and separate in a direction intersecting the surface of the intermediate transfer belt.   The intermediate transfer belt passes the intermediate transfer belt in a travel path after passing the position where the secondary transfer is performed by the secondary transfer unit and before reaching the position where the primary transfer is performed by the primary transfer unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is in contact with a surface of the belt. An image forming apparatus comprising belt cleaning means for cleaning the surface of the intermediate transfer belt,
In the travel path from when the intermediate transfer belt passes through the position where the cleaning is performed by the belt cleaning means and before reaching the position where the primary transfer is performed, the polishing member is placed on the surface of the intermediate transfer belt. The image forming apparatus according to claim 1, wherein the image forming apparatus is in contact with the image forming apparatus.   When the length in the running direction of the intermediate transfer belt at the contact surface that contacts the intermediate transfer belt of the polishing member is X, and the thickness of the polishing member in the direction orthogonal to the contact surface is Y, X The image forming apparatus according to claim 1, wherein the image forming apparatus is set to satisfy ≧ Y.   6. The contact angle formed between the end surface of the polishing member on the side on which the intermediate transfer belt enters and the surface of the intermediate transfer belt is set to 90 ° or less. The image forming apparatus according to claim 1. The process unit includes an image carrier unit having at least the image carrier and a development unit having at least the developing unit, and the image carrier unit and the development unit are configured to be separable. ,
The image forming apparatus according to claim 1, wherein the polishing member is disposed in the image carrier unit or the developing unit.   The image forming apparatus according to claim 1, wherein the polishing member is made of a solid material.   The image forming apparatus according to claim 1, wherein the polishing member is a foam member.   The image forming apparatus according to claim 1, wherein the polishing member is made of melamine resin.   The image forming apparatus according to claim 1, wherein the polishing member is formed in a roller shape, and the roller-shaped polishing member is configured to be rotatable.   The image forming apparatus according to claim 1, wherein the intermediate transfer belt is configured to be able to travel in a direction opposite to a traveling direction when image formation is performed.

Images