JP2006313247A - Process unit and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and easy-to-carry process unit which has installation stability even when it is put outside of an image forming device, and which causes little light exposure to a photoreceptor. <P>SOLUTION: A transfer belt of a process unit can change its forms to take a first form for forming an image, and a second form for protecting a photoreceptor. Since the transfer belt changes its forms in such a manner that it winds around the photoreceptor, the process unit can be made compact and easy-to-carry. The cross-sectional surface of the process unit can be configured to be generally quadrangle, thereby improving its installation stability and protecting the photoreceptor from light exposure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming process unit including a photosensitive member and a transfer belt, and an image forming apparatus including the process unit.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine and a printer, a process unit (or a process cartridge, etc.) that can be easily detached from an image forming apparatus by integrating each means or a plurality of means constituting an image forming process. (Also called). For example, there are a transfer belt unit including a transfer belt, a photoconductor unit including a photoconductor, a development unit including a developing device, and an imaging unit including a photoconductor and a developing device.

  These are mainly for the convenience of maintenance operations such as maintenance and replacement of each part, troubles such as jamming in the main body. Since these units can be easily attached and detached, the efficiency of maintenance increases, the purpose can be easily achieved, and the current state can be restored.

  Furthermore, in recent years, a process unit in which a transfer belt and a photoreceptor are integrated has been proposed and commercialized (for example, see Patent Document 1).

  In Patent Document 1, a photosensitive member cartridge that is detachable from a main body, in which a photosensitive member and a transfer belt disposed above the photosensitive member are integrated so as to straddle a drum-like developing device in which four color developing devices are set. It is shown. This makes it easy to detach and improve the maintainability.

  However, in the photoconductor cartridge as proposed in Patent Document 1, a considerably large area of the photoconductor that is opposed to the developing device when mounted in the main body of the image forming apparatus is not opposed when detached from the main body. It will be exposed in the state of. Photoconductors are particularly susceptible to light exposure, which causes quality degradation. In addition, if the surface of the photoreceptor is exposed, there is a high possibility that the surface is accidentally damaged.

  This is because each image forming unit is arranged along the periphery of the photoconductor, and only a part of the image forming unit is integrated with the photoconductor, so that the region of the photoconductor facing the remaining image forming unit is necessarily formed. As a result, it becomes a blank part and the photosensitive member is exposed.

On the other hand, it has been considered that some protective cover is provided at the time of detachment with respect to the blank portion, that is, the region of the photosensitive member to which the image forming means is opposed when the process unit is mounted inside the main body. As a typical example, there has been proposed setting of a protective cover that retracts to a position where it does not become an obstacle to the opposite developing device when mounted in the main body, and moves when removed from the main body to cover a necessary photoconductor area ( For example, see Patent Document 2).
JP-A-6-110261 Japanese Patent No. 2531723

  When a protective cover as shown in Patent Document 2 is used, the structure for opening and closing the protective cover is complicated, the process unit is increased in size by the provision of the protective cover and its opening / closing mechanism, and the shape is stable in installation. In many cases, the shape was inconvenient.

  Furthermore, in the process unit in which the above-described conventional transfer belt and the photoconductor are integrated, the size is inconvenient to carry or a relatively small photoconductor is disposed below the large intermediate transfer unit. When placed outside the apparatus due to a paper jam or the like, there are problems such as unstable installation and exposure of the photoreceptor to light.

  The object of the present invention is to make the process unit capable of being compact and easy to handle, have good installation stability when placed outside the machine, and further prevent the exposure of light to the photoconductor, and its function sufficiently. An image forming apparatus is provided.

  In order to solve the above problems, the present invention has the following features.

(Claim 1)
At least one transfer belt roller in a process unit detachable from an image forming apparatus, comprising: a drum-shaped photoconductor; a transfer belt that contacts the drum-shaped photoconductor; and a plurality of transfer belt rollers that stretch the transfer belt. And a first sub-unit including the drum-shaped photoconductor, a second sub-unit including at least one other transfer belt roller, and a connection for rotatably connecting the first and second sub-units. A transfer belt roller included in the first subunit and another transfer belt roller included in the second subunit are in contact with the drum-shaped photosensitive member. And the transfer belt and the drum-shaped photoreceptor are in contact with each other at a first contact area, and the transfer bell. Process units and the and the drum-shaped photosensitive member, and a second form in contact with the second contact area than the first contact area, characterized in that it is deformable to each other.

(Claim 2)
The process unit according to claim 1, further comprising an operation lever, wherein the process unit is mutually deformed into the first form and the second form in conjunction with the operation of the operation lever.

(Claim 3)
A belt cleaning unit that is disposed opposite to another transfer belt roller included in the second subunit and collects the toner on the transfer belt; and the belt cleaning unit includes: 3. The process unit according to claim 1, wherein in the second form, the process unit is in a state of facing another transfer belt roller included in the second subunit. 4.

(Claim 4)
The photosensitive member cleaning means for collecting toner on the drum-shaped photosensitive member, wherein the belt cleaning means is in a position facing the photosensitive member cleaning means in the second embodiment. 3. The process unit according to 3.

(Claim 5)
In the image forming apparatus detachably including a drum-shaped photoconductor, a transfer belt that comes into contact with the drum-shaped photoconductor, and a plurality of transfer belt rollers that stretch the transfer belt, the process unit includes: A first subunit including at least one transfer belt roller and the drum-shaped photosensitive member, a second subunit including at least one other transfer belt roller, and the first and second subunits rotate with each other. A transfer belt roller included in the first subunit and another transfer belt roller included in the second subunit. The transfer belt roller included in the second subunit is connected to the drum shape. By rotating with each other in contact with the photosensitive member, the transfer belt and the drive belt are interlocked with the mounting operation to the image forming apparatus main body. The transfer belt and the drum-shaped photoconductor are deformed into a first form in which the photoconductor is in contact with the first contact area and interlocked with an operation of detaching from the image forming apparatus main body. An image forming apparatus, wherein the image forming apparatus is deformed into a second form in contact with a second contact area larger than the first contact area.

(Claim 6)
A guide member for guiding the mounting of the process unit; at least one of the first subunit and the second subunit abuts on the guide member; and the process unit is moved to the first form. The image forming apparatus according to claim 5, further comprising a guide abutting portion to be deformed.

According to the invention of claim 1,
A process unit including a photoconductor and a transfer belt changes the shape of the transfer belt so that the transfer belt extends straight and the contact area with the photoconductor is reduced, and the transfer belt is wound around the photoconductor Thus, the second embodiment in which the contact area with the photosensitive member is increased can be mutually deformed.

  Thereby, the process unit can take a convenient shape according to the use state. For example, when it is not attached to the image forming apparatus, it is compact and convenient to handle, and the installation property is improved, and further, the photosensitive member can be protected from light exposure. Further, when inserted into the image forming apparatus, it can be deformed into a shape capable of image formation.

According to invention of Claim 2,
By operating the lever provided on the process unit by the operator, it becomes possible to deform the process unit, appropriately and easily according to the intention of the operator, and to a convenient shape suitable for the use state can do.

According to invention of Claim 3,
When the process unit is deformed, the position of the belt cleaning means does not change integrally with the transfer belt roller that comes into contact with the transfer belt, so that the entire process unit is easy to handle while maintaining the function contributing to image formation. It can be downsized.

According to invention of Claim 4,
Since the position of the belt cleaning means can be moved to a position facing the photoconductor cleaning means when the process unit is attached or detached, the entire process unit can be reduced in size and can be configured in a substantially rectangular shape while protecting the photoconductor. Installation stability can be further improved.

According to the invention of claim 5,
When attaching / detaching the process unit to / from the image forming apparatus main body, the process unit can be automatically deformed by the attaching / detaching operation, and it is appropriately and easily formed into a convenient shape according to the attached or detached state. be able to.

According to the invention of claim 6,
By having a guide member in the main body of the image forming apparatus, when the process unit is attached to or detached from the main body of the image forming apparatus, it can be easily deformed by inserting or removing the process unit along the mounting guide. A convenient shape suitable for the state can be obtained.

  A configuration example of the process unit according to the present invention and an overall configuration example of the image forming apparatus will be described with reference to FIGS. 1 to 5. In this embodiment, an image forming apparatus that employs a four-cycle color image forming method and a process unit that is a component thereof will be described as an example.

(Process unit configuration)
FIG. 1 is a cross-sectional view showing an embodiment of a process unit according to the present invention, and shows a configuration of the process unit as a single unit in a second form detached from the image forming apparatus main body.

  The process unit 10 includes constituent elements having the following reference numerals 11 to 22.

  Reference numeral 11 denotes a photoconductor for forming a toner image. A charging device 12 charges the surface of the photoconductor 11. Reference numeral 13 denotes a transfer belt for transferring a toner image developed on the photoreceptor 11 by a developing unit described later. Reference numeral 14 denotes a primary transfer roller for transferring a toner image onto the transfer belt 13 and also functions as a transfer belt roller for stretching the transfer belt 13. Reference numeral 14 a denotes a transfer belt roller a for stretching the transfer belt 13. A transfer belt roller b for stretching the transfer belt 13 has a function of assisting secondary transfer by facing a secondary transfer roller described later when the image forming apparatus body is mounted. A photoconductor cleaner 16 scrapes off the primary transfer residual toner on the surface of the photoconductor 11. Reference numeral 17 denotes a waste toner container a that collects the residual toner scraped off by the photoconductor cleaner 16. The photoconductor cleaner 16 and the waste toner container 17 function as photoconductor cleaning means according to the present invention.

  Reference numeral 18 denotes a transfer belt roller c for stretching the transfer belt 13. A transfer belt cleaner 19 scrapes off the secondary transfer residual toner on the surface of the transfer belt 13. A waste toner container 20 collects the residual toner scraped off by the transfer belt cleaner 19. The transfer belt cleaner 19 and the waste toner container 20 function as a belt cleaning unit according to the present invention. Reference numeral 21 denotes a transfer belt roller d for stretching the transfer belt 13. Reference numeral 22 denotes a handle for making it easy to hold the process unit 10, which rotates around the axis of the photosensitive member 11.

  The process unit 10 is roughly divided into two subunits other than the transfer belt 13.

  One is a first subunit 101 including a photoconductor 11, a charging device 12, a primary transfer roller 14, a transfer belt roller a14a, a transfer belt roller b15, a photoconductor cleaner 16, a waste toner container a17, and a handle 22. These are integrally supported by a first support frame (not shown). The other is a second subunit 102 including a transfer belt roller c18, a transfer belt cleaner 19, a waste toner container b20, and a transfer belt roller d21, which are integrally supported by a second support frame (not shown). Has been. And the 1st support frame and the 2nd support frame are connected by the below-mentioned connecting member 25, and the 1st subunit 101 and the 2nd subunit 102 are mutually rotatable. .

  With reference to FIG. 3, the positional relationship of the first and second subunits in the first and second forms of the process unit 10 will be described.

  FIG. 3A shows the state of each subunit in the second mode. FIG. 3B shows the state of each subunit in the first form.

  The first subunit 101 and the second subunit 102 are engaged and integrated with each other by a first support frame and a second support frame (not shown). The integrated first and second subunits are coupled to each other by a connecting member 25 so as to be rotatable as shown in the figure. That is, the first and second sub-units are respectively connected to both ends of the connecting member 25 in the longitudinal direction. Rotating shafts 251 and 252 are rotatably attached to the respective support frames in which the units are integrated.

  In this way, the relative position within the first and second subunits in the process of deformation from the second form to the first form or from the first form to the second form. Although the relationship does not change, the positional relationship between the first subunit 101 and the second subunit 102 changes in the direction indicated by the arrow A.

  The transfer belt 13 is originally an endless belt that is flexible and can be deformed. The transfer belt 13 hangs on the rollers of both subunits, and also connects both subunits. Accordingly, as the relative positional relationship between the first subunit 101 and the second subunit 102 changes, the shape of the transfer belt 13 also changes. In other words, the positional relationship between the first subunit 101 and the second subunit 102 changes within the range allowed by the shape of the transfer belt 13.

  Further, the transfer belt 13 must be stretched so as not to sag. Accordingly, the transfer belt roller of either the first or second subunit needs to have a function of applying tension to the transfer belt. In the process unit 10, the second subunit is always configured to be tensioned outward (in the direction of arrow B in FIG. 3).

  FIG. 4 shows another example of the method for connecting the first subunit and the second subunit. 4A shows the state of each subunit in the second form, and FIG. 4B shows the state of each subunit in the first form.

  FIG. 4 differs from FIG. 3 only in the position of the connecting member.

  In FIG. 4A, the connecting member 26 is rotatably attached to the respective support frames in which the first and second subunits are integrated at both ends in the longitudinal direction by the rotation shafts 261 and 262, respectively. Yes. Accordingly, the change in the positional relationship between the first subunit 101 and the second subunit 102 in FIG. 4B (the direction indicated by the arrow A) is also different. As another example of the connecting method, the connecting members 25 and 26 in FIGS. 3 and 4, both connecting members may be used, and various other connecting methods are possible.

  Returning to FIG. 1, in the second embodiment in which the process unit 10 is detached from the main body of the image forming apparatus, the waste toner container 17 constituting the photosensitive member cleaning means and the waste toner container 20 constituting the belt cleaning means. Are positions that face each other and that form the bottom surface of the process unit 10. With such a configuration, in the second embodiment detached from the main body of the image forming apparatus, the upper side of the photoconductor 11 is protected by contact with the transfer belt 13, and the lower side of the photoconductor 11 is provided with the waste toner container 17 and the waste. It is protected by facing the toner container 20, and exposure and physical contact by external light can be avoided. Further, the overall shape of the process unit can be made compact, handling becomes easy, and stability at the time of installation can be improved.

  FIG. 2 is a cross-sectional view showing a configuration of the process unit as a single unit in the first embodiment mounted on the image forming apparatus main body. The same components as those in FIG. 1 are denoted by the same reference numerals.

  In the process unit 10 in the second form, the second subunit 102 is deformed to the first form by turning in the direction indicated by the arrow A with the connecting portion 25 as a turning shaft (see FIG. 3). .

  In the first embodiment in which the process unit 10 is mounted on the image forming apparatus main body, the transfer belt 13 above the photoconductor 11 has a contact area with the photoconductor 11 narrowed only to an area necessary for transfer. The waste toner container 20 constituting the belt cleaning means extends upward and is opposed to the waste toner container 17 constituting the photoconductor cleaning means while facing the transfer belt roller 18, and is separated from the position facing each other. The exposed area below is increased. With such a configuration, in the first embodiment attached to the main body of the image forming apparatus, a space is formed below the photoconductor 11 so that a developing device 30 described later is opposed to the image forming apparatus on the main body side. It is possible to realize an arrangement configuration that can sufficiently exhibit an image forming function as a forming apparatus.

(Configuration of image forming apparatus)
FIG. 5 is a sectional view showing an embodiment of the image forming apparatus according to the present invention, and shows a configuration in a state where the process unit according to the present invention is mounted.

  The process unit 10 in FIG. 5 is in the first form. The main body of the image forming apparatus 1 mainly includes the following components.

  A developing device 30 performs color development of four colors. 30C, 30M, 30Y, and 30K constituting the developing device 30 use developers having reproduction colors of cyan, magenta, yellow, and black (hereinafter abbreviated as C, M, Y, and K, respectively). The developing unit for developing the photosensitive member 11. Each developing unit is attached to a support frame (not shown), and is integrated in a rotatable state. Each developing unit faces the photosensitive member 11 of the process unit 10 by rotating the developing device 30 as a whole. Thus, the photosensitive member 11 can be sequentially developed with the toners of the respective reproduction colors. FIG. 5 shows a state in which the developing unit having 30 K, that is, a black developer develops the photoconductor 11. Further, the order of the developing units in the rotation direction is arbitrary.

  An exposure apparatus 31 performs image exposure on the photosensitive member 11. Reference numeral 41 denotes a paper feed tray on which a recording medium (usually paper) S used for image formation is stacked. Reference numeral 43 denotes a transfer roller, which is disposed facing the transfer belt 13 of the process unit 10. A fixing roller 44 fixes the toner image transferred to the recording medium S. Reference numeral 46 denotes a paper discharge tray from which the recording medium S after image formation is discharged.

(Image formation flow)
The photoconductor 11 rotating in the direction of the arrow P is uniformly charged by the charging device 12, and image exposure is performed by the exposure device 31 from between the charging device 12 and the developing device 30 to form a latent image. Next, the latent image on the photoconductor 11 is developed by one of the developing units of the developing device 30, and any one of CMYK toner images is formed.

  Next, the transfer roller 14 applies a transfer electric field while pressing the transfer belt 13 conveyed in the direction of the arrow B in synchronization with the photoconductor 11 against the photoconductor 11 to transfer the toner image on the photoconductor 11 to the transfer belt. 13 is transferred. The transfer residual toner on the photoconductor 11 is scraped off by the photoconductor cleaner 16, and the photoconductor 11 returns to a state where the above-described process can be repeated.

  Each time the above process is repeated, the developing unit 30 is rotated in the direction of the arrow D to replace the developing unit, and the process is repeated four times, so that toner images of CMYK four colors are transferred onto the transfer belt 13. The toner image of each color is transferred so that the positions of the four color toner images are aligned on the transfer belt 13 in synchronization with the conveyance of the transfer belt 13.

  On the other hand, the recording medium S on the paper feed tray 41 is sent out by the paper feed roller 41a in synchronization with the above-described image forming process, and is carried in the direction of arrow A by the carry roller. When the recording medium S is conveyed to the position of the transfer roller 43 disposed opposite to the transfer belt 13 in synchronization with the conveyance in the arrow B direction of the transfer belt 13 having the four-color superimposed toner image. The transfer roller 43 applies a transfer electric field from the back surface of the recording medium S to transfer the toner image on the transfer belt 13 to the recording medium S.

  The transfer belt 13 on which the four color toner images are transferred to the recording medium S is scraped off the transfer residual toner by the transfer belt cleaner 19 and returns to the initial state to prepare for the next image formation. The transfer belt cleaner 19 is retracted from the transfer belt when four colors are superimposed.

  On the other hand, the recording medium S to which the four color toner images are transferred is sent to the fixing roller 44. The fixing roller 44 fixes the transferred toner image on the recording medium S while conveying and passing the recording medium S. The recording medium S on which image formation has been completed by fixing is discharged onto the paper discharge tray 46 by the paper discharge roller 46a through the transport roller 45.

(Difference in process unit configuration)
As described above, the process unit 10 needs to have a shape as shown in FIG. 2 as an element of the image forming apparatus 1 in order for the image forming apparatus 1 to exhibit the image forming function (first in the present invention). Corresponds to the form). In other words, it is necessary that the photoconductor 11 is opposed to the position of the developing device 30. Further, a gap for exposure is required between the charging device 12 and the developing device 30 in accordance with the position of the exposure device 31. The transfer belt roller b15 needs to face the transfer roller 43.

  On the other hand, in the state where the process unit 10 is detached from the main body of the image forming apparatus 1, the above restriction is not necessary. On the other hand, when considering installation stability and prevention of light exposure to the photoreceptor, the process unit 10 preferably has a shape as shown in FIG. 1 (corresponding to the second embodiment of the present invention). In other words, the cross section can be made substantially rectangular, and is stable during installation. The photosensitive member 11 is wound around the transfer belt 13 to prevent light exposure.

  Therefore, the process unit according to the present invention achieves the function of the image forming apparatus in a state where the process unit is mounted on the image forming apparatus as one component thereof. In addition, the process unit according to the present invention can perform operations such as replacement and maintenance in a single state of being detached from the image forming apparatus. The shape of the process unit can be changed according to the convenience in that state by changing the shape of the transfer belt, depending on which state it is in.

  Further, the image forming apparatus according to the present invention cooperates with the process unit according to the present invention, and drives the deformation of the process unit by its detachment operation.

  The difference between the first form and the second form mainly depends on the difference in the shape of the transfer belt. The deformation process will be described below.

(Deformation process of 1st form and 2nd form)
An example in which the process unit 10 is deformed in conjunction with the operation of attaching to and detaching from the main body of the image forming apparatus 1 will be described.

  The deformation process of the first embodiment and the second embodiment will be described with reference to FIGS. 6 to 8 are cross-sectional views of the apparatus showing the state in which the process unit 10 is mounted on the main body of the image forming apparatus 1 as a state before mounting, during mounting, and after mounting. The same components as those in FIGS. 1 and 5 are denoted by the same reference numerals.

  FIG. 6 shows a state before mounting. A wearer (not shown) is holding the handle 22 to hang the process unit 10 and is about to put it into the main body of the image forming apparatus 1 from the opening portion where the paper discharge tray 46 at the top of the main body of the apparatus is flipped up. Here, the process unit 10 is in the same state as that shown in FIG. 1, that is, in the second form, and has a shape in which the transfer belt 13 is wound around the photoconductor 11.

  FIG. 7 shows a state during mounting. The process unit 10 is being lowered into the main body while the movement is restricted by the mounting guide (see FIG. 9) on the main body side. As will be described later, when the second subunit 102 starts to rotate by the action of the stop member engaged with the mounting guide, the waste toner container a17 and the waste at the time of detachment (that is, in FIG. 6). The interval between the toner containers b20 is widened in FIG. Further, the transfer belt 13 wound around the photoconductor 11 is slightly unwound.

  FIG. 8 shows a state after mounting. The movement restricted by the mounting guide on the main body side is stopped, and it can no longer be lowered, that is, the process unit 10 has been lowered into the main body. The distance between the waste toner container a17 and the waste toner container b20 is further increased, and the transfer belt 13 wound around the photoreceptor 11 is almost extended.

  The deformation process will be described by focusing on the movement of each component of the process unit 10 and the shape of the transfer belt.

  In FIG. 9, since the relative positional relationship in each of the first and second subunits does not change, the first subunit 101 and the second subunit 102 before, during, and after mounting. Only the state of is shown superimposed, and the movement of each subunit at the time of deformation is shown in one figure. Arrows A and B indicate the movement of the first and second subunits, respectively.

  As the process unit 10 has the handle 22 and is inserted into the main body of the image forming apparatus 1, first, the constituent parts of the first subunit 101 are moved to a predetermined position according to the mounting guide members 51 and 52 of the main body. (The direction is indicated by arrow A1 in FIG. 9).

  At this time, the constituent parts of the second subunit 102 are initially pulled by the first subunit 101 and moved according to the mounting guide member 53 (indicated by the arrow B1 in FIG. 9), When the guide contact portion of the second subunit 102 is restricted from entering inward from a predetermined position according to the stop member 54 (which is a part of the mounting guide member) of the apparatus main body (arrows B1 to B2 in FIG. 9). So that it is pulled while increasing the distance from the first subunit 101 (moving in the direction of arrow A2 in FIG. 9) within a range that allows deformation of the transfer belt 13 applied to both subunits. It moves (indicated by arrow B2 in FIG. 9).

  Accordingly, while the transfer belt 13 wound around the photosensitive member 11 in an L shape extends straight, the interval between the waste toner container a17 and the waste toner container b20, which is not restricted by the transfer belt 13, increases. Eventually, the mounting guides 51 to 54 are set so as to stop when the interval between the waste toner container a17 and the waste toner container b20 increases until the transfer belt 13 extends in a substantially I-shape.

  In this way, the process unit 10 is mounted at a position and form capable of forming an image, and the deformation from the second form to the first form at the time of attachment ends.

  At the time of detachment from the image forming apparatus, the reverse occurs, and the shape is changed from the first form to the second form as the handle 22 is lifted from the main body.

  The detached process unit automatically assumes the second form due to its own weight so that the center of gravity comes below the shaft of the photoconductor 11 with which the handle 22 is engaged while being hung by the handle 22. Alternatively, a fixing means for preventing unintended deformation of the shape may be separately provided at the time of detachment.

  In the above embodiment, the method of deforming the process unit 10 in conjunction with the attachment / detachment to / from the image forming apparatus main body has been described. That is, when attaching to and detaching from the apparatus main body, the restriction by the mounting guide on the main body side applies a force to deform the process unit. However, it is possible to achieve the same effect with other means for applying force without attaching and detaching the main body.

  As another exemplary embodiment, there is a method of deforming the process unit by operating a lever provided in the process unit. In this case, the deformation process itself may be exactly the same as described above, but the deformation of the transfer belt 13 is performed while the transfer belt 13 connecting the first subunit 101 and the second subunit 102 is deformed to be stretched. The operation of increasing the distance between the first subunit 101 and the second subunit 102 within the range allowed for deformation can be performed by lever operation.

  The lever may be provided relatively in either the first subunit 101 or the second subunit 102, or may be provided in both subunits, that is, in a plurality. The handle 22 may also serve as a lever, or may serve as a part of the lever.

  If the lever can be deformed, the process unit is in the second form before the main body is mounted, but the wearer must mount it in the main body while deforming to the first form by operating the lever. become. Further, when detaching from the main body, the process unit of the first form is taken out from the main body, transformed into the second form by lever operation, and installed in an appropriate place.

  In any of the above embodiments, the process unit is deformed in the same manner, and the process unit is deformed mainly in such a manner that the transfer belt is deformed and regulated. As a result, in any of the above-described embodiments, the components are arranged in a state where appropriate image formation is possible when the main body is mounted, and the photoconductor is prevented from being exposed to light and can be stably installed when detached.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modified forms are allowed within the scope as long as they are in accordance with the gist of the present invention.

It is sectional drawing which shows the structural example in the 2nd form of the process unit which concerns on this invention. It is sectional drawing which shows the structural example in the 1st form of the process unit which concerns on this invention. It is sectional drawing which shows the 1st example of connection of the some subunit in the process unit which concerns on this invention. It is sectional drawing which shows the 2nd example of connection of the some subunit in the process unit which concerns on this invention. 1 is a cross-sectional view illustrating a configuration example of an image forming apparatus equipped with a process unit according to the present invention. FIG. 4 is a cross-sectional view illustrating an example of a state of the process unit according to the present invention before being attached to the image forming apparatus main body. FIG. 6 is a cross-sectional view illustrating an example of a state in which the process unit according to the present invention is mounted on the image forming apparatus main body. FIG. 6 is a cross-sectional view showing an example of a state after the process unit according to the present invention is mounted on the image forming apparatus main body. FIG. 6 is a cross-sectional view showing an example of a change in position of each subunit when the process unit according to the present invention is mounted on the image forming apparatus main body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Process unit 11 Photoconductor 12 Charging device 13 Transfer belt 14 Primary transfer roller 16 Photoconductor cleaner 17 Waste toner container a
19 Transfer belt cleaner 20 Waste toner container b
22 Handle 25, 26 Connecting member 30 Developing device 30C Developing unit (for cyan)
30M development unit (for magenta)
30Y development unit (for yellow)
30K development unit (for black)
31 Exposure Device 41 Feeding Tray 43 Secondary Transfer Roller 44 Fixing Roller 46 Ejection Tray 51, 52, 53, 54 Guide Member 101 First Subunit 102 Second Subunit

Claims (6)

In a process unit that is detachable from an image forming apparatus, comprising a drum-shaped photosensitive member, a transfer belt that contacts the drum-shaped photosensitive member, and a plurality of transfer belt rollers that stretch the transfer belt.
A first subunit including at least one transfer belt roller and the drum-shaped photoreceptor;
A second subunit including at least one other transfer belt roller;
A connecting member for rotatably connecting the first and second subunits to each other;
The transfer belt roller included in the first subunit and the other transfer belt roller included in the second subunit rotate with each other while the transfer belt is in contact with the drum-shaped photoconductor. By
A first mode in which the transfer belt and the drum-shaped photoconductor are in contact with each other at a first contact area, and a first mode in which the transfer belt and the drum-shaped photoconductor are larger than the first contact area. A process unit characterized in that it is mutually deformable to a second form contacting with two contact areas. With an operating lever,
2. The process unit according to claim 1, wherein the process unit is deformed into the first form and the second form in conjunction with the operation of the operation lever. A belt cleaning unit provided opposite to the other transfer belt roller included in the second subunit to collect toner on the transfer belt;
3. The belt cleaning unit according to claim 1, wherein the belt cleaning unit is in a state of facing the other transfer belt roller included in the second subunit in the first form and the second form. Process units. Photoconductor cleaning means for collecting toner on the drum-shaped photoconductor,
The process unit according to claim 3, wherein the belt cleaning unit is located at a position facing the photoconductor cleaning unit in the second embodiment. In an image forming apparatus comprising a drum-shaped photoconductor, a transfer belt that contacts the drum-shaped photoconductor, and a process unit that includes a plurality of transfer belt rollers that stretch the transfer belt.
The process unit is
A first subunit including at least one transfer belt roller and the drum-shaped photoreceptor;
A second subunit including at least one other transfer belt roller;
A connecting member for rotatably connecting the first and second subunits to each other;
The transfer belt roller included in the first subunit and the other transfer belt roller included in the second subunit rotate with each other while the transfer belt is in contact with the drum-shaped photoconductor. By
In conjunction with the operation of mounting on the image forming apparatus main body, the transfer belt and the drum-shaped photoconductor are deformed into a first form in contact with the first contact area,
In conjunction with the operation of detaching from the image forming apparatus main body, the transfer belt and the drum-shaped photoconductor are deformed into a second form in which the second contact area is larger than the first contact area. An image forming apparatus. A guide member for guiding the mounting of the process unit;
At least one of the first subunit and the second subunit has a guide abutting portion that abuts the guide member and transforms the process unit into the first form. Item 6. The image forming apparatus according to Item 5.

Images