JP2007226007A - Image forming apparatus, image-formation unit, and method for assembling image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, etc. capable of easily securing the alignment of a processing device or the like. <P>SOLUTION: A developing unit 40 and a photoreceptor unit 50 are engaged with each other at four spots, and also the torsional rigidity of the photoreceptor unit 50 is made larger than that of the developing unit 40. Therefore, by engaging the developing unit 40 with the photoreceptor unit 50 having the larger torsional rigidity, the developing unit 40 is deformed to follow the photoreceptor unit 50 even if it is distorted. Namely, in such a case, the distortion of the developing unit 40 is corrected while the shape of the photoreceptor unit 50 is nearly kept. As a result, the alignment of the photoreceptor drum 52 of the photoreceptor unit 50 with various processing members positioned in the developing unit 40 is secured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a color printer or a color copying machine.

In a color image forming device, if the main body frame is distorted due to distortion of the main body installation surface, misalignment or misalignment occurs in various process devices for forming images, resulting in image defects such as color misregistration and color unevenness. Occurs.
For example, the mounting surface on which the image forming apparatus is mounted is not always constant, and there are various environments such as tilting and unevenness. When the image forming apparatus is placed on such a placement surface, a non-uniform load is applied from the placement surface, so that the main body frame is distorted, and the position of the process device or the like located inside is displaced. In this state, when image formation is attempted, the process apparatus is displaced from its original position, and thus color misregistration and color unevenness occur in the formed image.

  In order to solve such a problem, a method has been proposed in which the distortion of the installation surface is not affected by various process apparatuses located inside (see, for example, Patent Document 1). In this technique, the housing is divided into one housing having the process device and the device main body, and these are engaged by the three engaging portions so that the distortion of the installation surface is not affected by the process device.

JP 2000-310930 A

  By the way, since the process equipment has a lifetime, it needs to be replaced periodically. However, in the technique described in Patent Document 1, the frame that supports the process apparatus is a casing in which the exposure apparatus is integrated, and each process apparatus is supported by one casing and is integrally positioned. Yes. For this reason, it is difficult to arbitrarily attach or detach each process apparatus or a unit that supports the process apparatus.

  In addition, there is a method to position each process unit with its own housing in the main body of the equipment so that the process equipment can be exchanged. However, the distortion of each unit frame causes inconsistencies between the units, resulting in alignment. There is a problem that it is difficult to secure the system. If the alignment is not ensured, the distances between the various devices become non-uniform, causing problems such as belt meandering, color unevenness and color misregistration in the formed image.

  Therefore, the present invention has been made to solve the above technical problems, and an object of the present invention is to provide an image forming apparatus that can easily ensure alignment of a process apparatus or the like. is there.

  For this purpose, an image forming apparatus to which the present invention is applied includes a main body and an image forming unit that is supported by the main body and forms an image formed on a recording material. A first unit that supports a photoreceptor carrying an image; a second unit that supports at least one process member that acts on the photoreceptor; and has a stiffness that is different from that of the first unit; Engaging means for engaging one unit of the unit or the second unit following the other unit having higher rigidity than the one unit.

  Here, the engaging means can be characterized by engaging the first unit and the second unit at four or more locations. In addition, the image forming unit can be supported at three positions on the main body side of the image forming apparatus. Further, the first unit may further include a cleaning member that cleans the photosensitive member, a charging member that charges the photosensitive member, or an exposure device that exposes the charged photosensitive member. The process member may be a developing device that develops a toner image on the photosensitive member. Furthermore, the process member may be a belt member that is rotatably provided to transfer an image from the photosensitive member and transfer the image transferred from the photosensitive member to a recording material.

  Further, when the present invention is regarded as an image forming unit, the image forming unit of the present invention supports at least one of a first unit that supports a photoreceptor carrying an image and a process member that acts on the photoreceptor. Engage one of the first unit and the second unit by following the other unit, which has higher rigidity than the first unit Engaging means.

  Further, when the present invention is regarded as an image forming apparatus assembling method, the image forming apparatus assembling method of the present invention includes a first unit for supporting a photoconductor carrying an image, and a process member acting on the photoconductor. An image forming apparatus assembly method for assembling an image forming apparatus by supporting at least one second unit having a rigidity different from that of the first unit on the main body side, the first unit or An image forming unit is formed by engaging one unit of the second units with the other unit having higher rigidity than the one unit, and the image forming unit is supported on the main body side. be able to.

  Here, the first unit and the second unit may be detachable from each other. The image forming unit may be detachable from the main body side.

  According to the present invention, it is possible to provide an image forming apparatus capable of easily ensuring alignment of a process apparatus or the like.

Embodiments will be described below with reference to the accompanying drawings.
-First embodiment-
FIG. 1 is a schematic configuration diagram illustrating an entire image forming apparatus to which the exemplary embodiment is applied. The image forming apparatus shown in the figure is a multi-pass (4-cycle) color image forming apparatus.

The image forming apparatus includes an image forming unit 30 formed by engaging a plurality of units that form toner images to be transferred onto a sheet as a recording material. In addition, the image forming apparatus includes a conveyance member used for conveying a sheet such as a sheet tray 80 and various rolls, a fixing device 70 that fixes a toner image on the sheet, and each member in the image forming apparatus. And a control unit 20 that controls movement. Furthermore, the apparatus main body 10 of the image forming apparatus accommodates various members such as the image forming unit 30 and apparatuses.
The apparatus main body 10 includes a main body 10a that houses the image forming unit 30 and the like, and an openable / closable lid 10b provided on the upper surface of the main body 10a. By rotating the opening / closing lid 10b around the hinge 12 provided between the lid 10b and the main body 10a, a state in which the upper portion of the main body 10a is opened can be formed.

The image forming unit 30 includes a photoreceptor unit 50 as a first unit that supports the photoreceptor drum 52 and the like. The image forming unit 30 includes, as a second unit for the first unit, a developing unit 40 that supports a developing device 42 as an example of a process member, an intermediate transfer body 62 as an example of a process member, and the like. And a transfer unit 60 to be supported.
Since the photosensitive drum 52 and various process devices arranged in the image forming unit 30 have a lifetime, in this embodiment, the image forming unit 30 can be taken out from the upper portion of the main body 10a by opening the opening / closing lid 10b. It is possible to replace each unit or process device.

The photoconductor unit 50 includes a rotatable photoconductor drum 52 that carries a toner image, and a charging roll 53 as a charging member that charges the photoconductor drum 52 by charging it. The photosensitive unit 50 includes side plates 51 at both axial ends of the photosensitive drum 52 (see FIG. 2), and the photosensitive drum 52 is rotatably supported by the side plates 51. .
Further, the photoreceptor unit 50 includes a cleaning blade 54 as a cleaning member that scrapes off toner (residual toner) remaining on the photoreceptor drum 52 after the primary transfer to the intermediate transfer body 62, and scrapes off from the cleaning blade 54. And a toner collection bottle (not shown) for collecting the collected toner and storing the toner.
The photoconductor unit 50 includes an exposure device 55 that exposes a charged photoconductor drum 52 based on an image signal from an image processing device (IPS) (not shown). Note that the charging roll 53, the cleaning blade 54, the toner collection bottle, the exposure device 55, and the like may be integrally attached to the photosensitive unit 50 as described above, or detachable from the photosensitive unit 50. It can also be a subunit.

The developing unit 40 is an example of a developing device 42 that develops an electrostatic latent image formed on the photosensitive drum 52 by the exposure device 55 to form a toner image, and a process member that constitutes a part of the developing device 42. And a moving unit 43 for moving the developing unit 42a.
The developing device 42 includes four developing units 42a containing toners of the respective colors in order to form toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K). I have. Each developing device 42 a has a developing roll (mag roll) 42 b for developing the photosensitive drum 52.

  The moving unit 43 includes a driving source such as a motor M and a driving member (not shown) such as a cam or a link member, and each of the developing devices 42a approaches or moves away from the photosensitive drum 52. . More specifically, the moving unit 43 controls the Y, M, C, and K developing units 42a that are separated from the photosensitive drum 52 for one print output by a control signal from the control unit 20. In this order, the photosensitive drum 52 is opposed to enable full color output.

The transfer unit 60 includes an intermediate transfer body 62 that temporarily holds a toner image formed on the photosensitive drum 52, and a cleaner member 68 that removes residual toner on the intermediate transfer body 62 after the secondary transfer.
The intermediate transfer member 62 is disposed on the photosensitive drum 52 on the downstream side of the developing device 42, and temporarily holds the toner image formed on the photosensitive drum 52 by the developing device 42a. The intermediate transfer body 62 is an example of a process member, and includes an intermediate transfer belt 63 as a belt member and a plurality of roll-shaped members that rotatably support the intermediate transfer belt 63. In the present embodiment, a primary transfer roll 64, a stretch roll 65, a drive roll 66, and a backup roll 67 are provided as the roll-shaped members. When a belt-like member such as the intermediate transfer belt 63 is used for the intermediate transfer member 62, the intermediate transfer member 62 may be integrally supported by the photosensitive unit 50. In this case, this is the most preferable mode for preventing color shift (transfer shift) due to meandering of the intermediate transfer belt 63.

The primary transfer roll 64 is disposed inside the intermediate transfer belt 63, thereby forming a primary transfer portion 91 with the photosensitive drum 52, and the toner image formed on the photosensitive drum 52 is transferred to the intermediate transfer belt 63. Transfer on top.
The drive roll 66 stretches the intermediate transfer belt 63 and is disposed at a position opposite to the cleaner member 68 to assist the cleaning operation by the cleaner member 68. Further, the intermediate transfer belt 63 is circulated and driven (rotated) at a predetermined speed in the direction of arrow B by being driven by a motor (not shown) having excellent constant speed.

The backup roll 67 is arranged inside the intermediate transfer belt 63 and stretches the intermediate transfer belt 63. Further, the backup roll 67 forms a secondary transfer portion 92 between the backup roll 67 and the secondary transfer roll 83 disposed at a position opposed to each other with the intermediate transfer belt 63 interposed therebetween.
The tension roll 65 is provided inside the intermediate transfer belt 63 and between the primary transfer roll 64 and the drive roll 66, and plays a role of tensioning the intermediate transfer belt 63.
In the present embodiment, the intermediate transfer belt 63 is driven by the drive roll 66, but may be driven by another roll such as the tension roll 65. Further, the intermediate transfer belt 63 can be rotated by following the rotation of the photosensitive member 52.

The cleaner member 68 includes a roll-shaped member 68a pressed against the drive roll 66 and a cleaner blade 68b pressed against the roll-shaped member 68a. The roll-shaped member 68a electrostatically attracts residual toner on the intermediate transfer belt 63 that is being driven in a cyclic manner. The toner on the roll-shaped member 68a is scraped off by the cleaner blade 68b.
The cleaner member 68 removes residual toner on the intermediate transfer belt 63 after the secondary transfer roll 83 contacts the intermediate transfer belt 63 and performs secondary transfer. For this reason, in the first stage of image formation, the toner image being superimposed is separated from the intermediate transfer belt 63 so as not to be scraped off, and is in contact with the intermediate transfer belt 63 at a predetermined timing. Has been.
The cleaner member 68 may be constituted by, for example, a cleaning brush (not shown) and a cleaning blade (not shown), and the remaining toner on the intermediate transfer belt 63 is brought into contact with the intermediate transfer belt 63. Can also be removed.

In the primary transfer unit 91, the toner image on the photosensitive drum 52 is electrostatically attracted sequentially to the intermediate transfer belt 63 so that the toner image is superimposed on the intermediate transfer belt 63. The primary transfer roll 64 is given a predetermined primary transfer bias to assist the primary transfer.
In the secondary transfer unit 92, the secondary transfer roll 83 is grounded and a secondary transfer bias is formed between the secondary transfer roller 83 and the backup roll 67, and the toner image is secondarily transferred onto the sheet conveyed to the secondary transfer unit 92. The
The secondary transfer roll 83 is provided so as to be movable with respect to the intermediate transfer belt 63 by a drive unit (not shown), and an interimage after the toner image superimposed up to cyan passes through the secondary transfer unit 92. The intermediate transfer belt 63 is pushed out. Then, the toner image on which the last black (K) toner on the intermediate transfer belt 63 is superimposed is secondarily transferred onto the sheet.

  Next, the paper transport system will be described. A sheet tray 80 on which sheets P are stacked is provided at the lower part of the apparatus main body 10. Further, on the upper portion of the paper tray 80, a drawing roll (a nudger roll) 81 that comes in contact with the stacked paper P and picks up from the upper surface, and a supply roll and a paper roll for paper one by one on the downstream side of the drawing roll 81 are provided. A paper-sheet-spreading section (not shown) made up of rolls is provided. In addition, a takeaway roll (not shown) is provided on the downstream side of the paper handling unit to temporarily stop the paper and then retransmit it at a predetermined timing.

The paper path 89 that contacts the downstream side of the takeaway roll, in the photosensitive unit 50, once stopped and then restarted at the same time, and the paper is adjusted while performing registration adjustment on the secondary transfer unit 92. A registration roll (registration roll) 82 is provided.
In the fixing device 70, a heat roll 71 that heats the toner image formed on the paper and a pressure roll 72 that faces the heat roll 71 and presses the paper during heating are provided.
Further, in the downstream direction of the fixing device 70, a conveyance roll 85 that conveys the fixed sheet to the downstream side, a discharge roll 86 that discharges the sheet conveyed by the conveyance roll 85 to the outside of the apparatus, and an open / close lid A discharge tray 87 is provided on the upper surface of 10b to collect (stack) the sheets discharged by the discharge roll 86.

Next, an image forming process using this image forming apparatus will be described. The image forming apparatus receives an output request from an externally connected PC (personal computer), an image reading apparatus, or the like, and starts an image forming process based on an instruction from the control unit 20. In the case of full-color print output, the moving unit 43 first causes the yellow (Y) developing device 42a to approach the photosensitive drum 52. First, when forming a yellow toner image, the photosensitive drum 52 that rotates clockwise (in the direction of arrow A in the figure) is charged by the charging device 53.
Thereafter, exposure based on image information corresponding to yellow is performed by, for example, laser light from the exposure device 55, and an electrostatic latent image is formed on the photosensitive drum 52. Thereafter, development is performed by the developing roller 42 b, and then a yellow toner image is transferred onto the intermediate transfer belt 63 by the primary transfer unit 91. After the transfer, the intermediate transfer belt 63 onto which the yellow toner image has been transferred moves toward the secondary transfer portion 92. At this time, the secondary transfer roll 83 and the cleaner member 68 are retracted (separated) from the intermediate transfer belt 63, thereby preventing the toner image on the intermediate transfer belt 63 from being scraped off.

  The surface of the photosensitive drum 52 after the primary transfer of yellow is scraped off by the cleaning blade 54 and moves toward the charging device 53 for the next toner image formation. Further, the moving unit 43 separates the yellow developing device 42 a from the photosensitive drum 52 and causes the magenta developing device 42 a to face the photosensitive drum 52 in time for the next development timing. After exposure based on magenta image information is performed by the exposure device 55, a magenta toner image is formed on the photosensitive drum 52 by the developing device 42a. The toner image on the photosensitive drum 52 is superimposed on the intermediate transfer belt 63 in the primary transfer portion 91. Similarly, cyan and black toner images are sequentially superimposed on the intermediate transfer belt 63 to complete primary transfer.

The secondary transfer roll 83 is advanced with respect to the backup roll 67 in the inter-image after the primary transfer to the cyan toner image is completed and the toner image superimposed up to cyan passes through the secondary transfer unit 92. (Extruded) Then, secondary transfer is performed from the intermediate transfer belt 63 to the sheet while the secondary transfer roll 83 is in contact (contact) with the backup roll 67.
Further, the cleaner member 68 is pressed against the intermediate transfer belt 63 by an inter-image after the toner image superimposed up to cyan passes through the cleaner member 68. This inter-image can be said to be an area where no toner image is formed on the intermediate transfer belt 63 or the photosensitive drum 52 (a toner image is not planned to be formed) and a part where writing by exposure is not planned. it can.
The sheet on which the toner image is transferred by the secondary transfer unit 92 is conveyed to the fixing device 70 and the toner image is fixed. After that, it is output to the outside of the apparatus through the transport roll 85 and the discharge roll 86 and is stored in the discharge tray 87. As described above, the image forming process for outputting one color print is completed.

Next, the image forming unit 30 will be described in more detail.
FIG. 2 is a perspective view showing the image forming unit 30 and the apparatus main body 10. Further, this drawing shows a state in which the image forming unit 30 is taken out from the apparatus main body 10. In this figure, the opening / closing lid 10b (see FIG. 1) is not shown.

  As shown in the figure, the developing unit 40 includes a supporting frame 41 that supports a developing device 42 (see FIG. 1) and the like and is formed from a plurality of surfaces. In addition, two fastening portions 41a protruding outward as an example of the engaging means are formed on one side surface of the support frame 41 and in the vicinity of the end located on the photosensitive unit 50 side. Although illustration is omitted, two fastening portions 41 a are similarly formed on the other side surface of the support frame 41. That is, in the present embodiment, a total of four fastening portions 41 a are formed on the support frame 41. Further, the support frame 41 is provided with one support leg 41b as a support portion for supporting the support frame 41 formed so as to protrude from the lower surface toward the apparatus main body 10 side.

The photoreceptor unit 50 includes a support frame that supports the photoreceptor drum 52 and the like disposed therein. The support frame includes side plates 51 provided at both ends in the axial direction of the photosensitive drum 52, a connecting plate 56a that connects the both side plates 51 at the upper portion, and a connecting plate 56b that connects the lower portions. ing.
Two fastening portions 51a that project outward are provided as one example of the engaging means in the vicinity of the end side located on the side of the developing unit 40 on the side plate 51. Further, two fastening portions 51a that protrude outward are also provided in the vicinity of the side edge of the side plate 51 that is located on the transfer unit 60 side. That is, the one side plate 51 is provided with a total of four fastening portions 51a. Further, the lower side of the side plate 51 is provided with one support leg 51b as a support portion that is formed to project from the lower side toward the apparatus main body 10 and supports the side plate 51. Although not shown, the other side plate 51 is also provided with four fastening portions 51 a and one support leg 51 b as in the case of the one side plate 51.

The transfer unit 60 includes a support frame that supports an intermediate transfer member 62 and the like disposed therein. This support frame is composed of side plates 61 provided at both ends in the width direction of the intermediate transfer belt 63, and a connecting plate (not shown) provided on the back side in the drawing and connecting the side plates 61. Has been.
Two fastening portions 61a as an example of engaging means are provided in the vicinity of one side plate 61 near the end located on the photosensitive unit 50 side. Although not shown, the other side plate 61 is also provided with two fastening portions 61 a as in the case of the one side plate 61. That is, in this embodiment, a total of four fastening portions 61a are formed on the support frame. The support frame is not provided with a support portion for supporting the support frame on the apparatus main body 10.

  In the state shown in this drawing, the developing unit 40 and the photoconductor unit 50 are engaged at four locations. That is, four fastening portions 41a formed on the support frame 41 of the developing unit 40 and four fastening portions 51a formed on the side of the developing unit 40 of the side plate 51 of the photosensitive unit 50 are respectively screw members or the like. By engaging with each other, both units are engaged by a total of four engaging portions. Similarly, the photoconductor unit 50 and the transfer unit 60 are engaged at four locations by the fastening portions 51a and 61a.

By the way, when there is a shift in alignment between the units, there is a possibility that color unevenness or image shift may occur.
In the present embodiment, a belt-like member such as the intermediate transfer belt 63 is used as the intermediate transfer member 62. In this case, if the alignment of the rolls stretching the intermediate transfer belt 63 such as the driving roll 66 and the stretching roll 65 (see FIG. 1) stretching the intermediate transfer belt 63 is shifted, the intermediate transfer belt 63 is shifted. This causes a meandering of the image and causes image shift.
Further, in this embodiment, non-contact development is adopted. In particular, in this non-contact development method, when the alignment is shifted, the distance between the developing roll (mag roll) 42b (see FIG. 1) and the photosensitive member 52 is non-uniform. It causes uneven color.

  Therefore, in the present embodiment, the developing unit 40 and the photoconductor unit 50 are engaged at four positions, and the torsional rigidity of the photoconductor unit 50 is made larger than the torsional rigidity of the developing unit 40. For this reason, even if the developing unit 40 is distorted, the developing unit 40 is deformed so as to follow the photosensitive unit 50 by engaging the developing unit 40 with the photosensitive unit 50 having high torsional rigidity. That is, in this case, the distortion of the developing unit 40 can be corrected while the shape of the photoconductor unit 50 is substantially maintained. As a result, alignment between the photosensitive drum 52 of the photosensitive unit 50 and the various process members located in the developing unit 40 can be ensured. The relationship between the transfer unit 60 and the photoconductor unit 50 is also the same. In this embodiment, the torsional rigidity of the photoconductor unit 50 is made larger than the torsional rigidity of the transfer unit 60. For this reason, even when the transfer unit 60 is distorted, the alignment is adjusted by engaging both units, and a state in which the alignment is ensured can be formed.

  There are various methods for increasing the rigidity of the photoconductor unit 50. For example, there are a method of increasing the thickness of each member, a method of installing a plate for connecting the members, a method of forming a frame in a box shape, and the like. There is also a method in which the frame of the photosensitive unit 50 is formed of metal and the other units are formed of resin. In the present embodiment, the frame of the photoconductor unit 50 is made of metal, and the entire frame is formed in a box shape using the connection plates 56a and 56b as described above. On the other hand, the frame of the developing unit 40 is formed of resin and has a small thickness. This relatively increases the torsional rigidity on the photosensitive unit 50 side. As for the transfer unit 60, since only one of the transfer plates provided with the connection plate is provided, the overall torsional rigidity is small. As a result, the torsional rigidity of the photoconductor unit 50 is larger than the torsional rigidity of the developing unit 40 and the torsional rigidity of the transfer unit 60.

In the present embodiment, the photoconductor unit 50 and the developing unit 40 can be separated by releasing the engagement. Further, the photoconductor unit 50 and the transfer unit 60 can be separated by releasing the engagement.
Since each unit has a lifetime, it needs to be replaced periodically. In this embodiment, it is possible to replace only the unit that needs to be replaced by releasing the engagement between the units. It is. And by making each unit separable, the minimum unit replacement | exchange is enabled and the low running cost is implement | achieved.
Furthermore, in this embodiment, in order to improve the convenience for the user, the individual units are not attached to and detached from the apparatus main body 10 but are detachable as the image forming unit 30 in which each unit is integrated. Yes. In the present embodiment, since the image forming unit 30 can be taken out of the apparatus main body 10, it is easy to replace each unit constituting the image forming unit 30.

When the unit is replaced, the image forming unit 30 is rearranged inside the apparatus main body 10 through the opening 10c of the apparatus main body 10 from the state shown in FIG. In the present embodiment, even when the apparatus main body 10 is installed on a distorted installation surface, the image forming unit 30 is not affected by the distortion of the installation surface.
Specifically, as described above, the image forming unit 30 alone is used to ensure alignment between the units, and the image forming unit 30 in which alignment is ensured is supported on the apparatus main body 10 at three points. More specifically, the image forming unit 30 includes three support legs 41b and 51b formed on the image forming unit 30 side and three engagement holes 10d formed on the apparatus main body 10 side. By being engaged by a member or the like, it is arranged at a predetermined position in the apparatus main body 10.

  Since the image forming unit 30 is supported by the apparatus main body 10 at three locations, when distortion occurs on the apparatus main body 10 side, this distortion is suppressed from being transmitted to the image forming unit 30 side. In this embodiment, the three support legs (41b, 51b) are provided at one place (41b) on the developing unit 40 and at two places (51b) on the photosensitive unit 50. The image forming unit 30 can be formed. For example, three locations can be provided only on the photoconductor unit 50, two locations can be provided on the photoconductor unit 50, and one location can be provided on the transfer unit 60.

  In general, when a certain device is supported on the mounting surface at three points and the contact area at each supporting point is small, for example, when a load acts on one of the three points from the mounting surface, the remaining A line connecting the two points serves as a rotation axis, and the entire apparatus tries to rotate around the rotation axis. In this case, although the entire apparatus is to be rotated, if the apparatus itself has rigidity, no distortion occurs. In the present embodiment, as described above, the image forming unit 30 is supported with respect to the apparatus main body 10 at three locations having a small contact area, so that it is possible to suppress distortion from being transmitted from the apparatus main body 10. However, for example, when one point is added and supported by four points, the device tries to rotate around the rotation axis formed from the two contact points as described above, but the rotation is performed by the added one point. Will be distorted in the apparatus.

From the opposite viewpoint, when a strain is transmitted between certain members (when a certain member is intended to be corrected by another member) and the contact area at each contact point between the members is small, It is necessary to support at 4 points or more.
For this reason, in this embodiment, as described above, the photosensitive unit 50 and the developing unit 40 are engaged with each other by four engaging portions. Similarly, the photoconductor unit 50 and the transfer unit 60 are engaged by four engaging portions. If the number of the engaging portions is three, the developing unit 40 and the transfer unit 60 cannot be corrected using the photoconductor unit 50 for the reason described above. In this embodiment, the photoconductor unit 50 and the developing unit 40 are engaged at four locations, but any number of engaging portions may be used as long as there are four or more locations. Further, for example, when the photoconductor unit 50 and the developing unit 40 or the transfer unit 60 are engaged with each other with an engagement portion having a large contact area, the number of engagement portions is set to 3 or less as shown below. it can.

-Second Embodiment-
FIG. 3 shows the developing unit 40 and the photoreceptor unit 50 when there are two engaging portions. Since the basic configuration is the same as that of the first embodiment, the description will focus on the differences. Further, in this drawing, illustration of the transfer unit 60 and the photosensitive drum 52 in the photosensitive unit 50 shown in FIG. 1 is omitted.
The developing unit 40 shown in this drawing has a guide plate 41d as an engaging means extending along one end of the support frame 41 on one side of the support frame 41 and located on the photosensitive unit 50 side. I have. The guide plate 41d is formed with a through hole 41c as an engaging means through which a fastening member such as a bolt is inserted. The other side surface is also provided with a guide plate 41d and a through hole 41c in the same manner as the one side surface.

On the other hand, a guide plate 51d as an engaging means and a through hole 51c are provided on the side plate 51 of the photoconductor unit 50 and also on the end located on the developing unit 40 side. The guide plate 51d and the through hole 51c are similarly provided in the other side plate 51.
The engagement between the two units is performed by a fastening member inserted through the through holes 41c and 51c. When both units are fastened by the fastening member, the guide plate 41d provided in the developing unit 40 and the guide plate 51d provided in the photoconductor unit 50 come into surface contact and come into pressure contact. For this reason, even if the developing unit 40 is in a distorted state, the developing unit 40 follows the photoconductor unit 50 side via the guide plate 41d and the guide plate 51d. As a result, the distortion of the developing unit 40 can be corrected. In this way, even if the number of engagement locations is less than 4, it is possible to make one unit follow the other unit by bringing the units into surface contact.

  According to the above embodiment, if only the frame rigidity of the photosensitive unit 50 is ensured, alignment of other units such as the developing unit 40 and the transfer unit 60 and the process apparatus can be ensured regardless of the installation environment of the apparatus. Further, other units such as the developing unit 40 and the transfer unit 60 and the apparatus main body 10 need only have a minimum rigidity, and the entire image forming apparatus can be reduced in weight.

1 is a schematic configuration diagram illustrating an entire image forming apparatus to which the exemplary embodiment is applied. It is the perspective view which showed the image forming unit and the apparatus main body. FIG. 6 is a diagram illustrating a developing unit and a photoconductor unit when there are two engaging portions.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Apparatus main body, 30 ... Image forming unit, 40 ... Developing unit, 41a ... Fastening part, 42a ... Developing device, 50 ... Photoconductor unit, 51a ... Fastening part, 52 ... Photoconductor drum, 53 ... Charging roll, 54 ... Cleaning blade 55 ... exposure device 60 ... transfer unit 61a ... fastening portion 63 ... intermediate transfer belt

Claims (10)

The body,
An image forming unit which is supported by the main body and forms an image formed on a recording material;
With
The imaging unit is
A first unit for supporting a photoreceptor carrying an image;
A second unit that supports at least one of the process members acting on the photoconductor, and has a rigidity that is different from that of the first unit;
Engagement means for engaging one unit of the first unit or the second unit following the other unit having a higher rigidity than the one unit;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the engaging unit engages the first unit and the second unit at four or more locations.   The image forming apparatus according to claim 1, wherein the image forming unit is supported at three positions on the main body side of the image forming apparatus.   The first unit further includes a cleaning member that cleans the photosensitive member, a charging member that charges the photosensitive member, or an exposure device that exposes the charged photosensitive member. The image forming apparatus according to 1.   The image forming apparatus according to claim 1, wherein the process member is a developing unit that develops a toner image on the photosensitive member.   2. The image according to claim 1, wherein the process member is a belt member rotatably provided to transfer an image from the photoconductor and to transfer the image transferred from the photoconductor to a recording material. Forming equipment. A first unit for supporting a photoreceptor carrying an image;
A second unit that supports at least one of the process members acting on the photoconductor, and has a rigidity that is different from that of the first unit;
Engagement means for engaging one unit of the first unit or the second unit following the other unit having a higher rigidity than the one unit;
An image forming unit. A main unit comprising: a first unit that supports a photoconductor that carries an image; and a second unit that supports at least one of the process members that act on the photoconductor and has a rigidity that is different from that of the first unit. An image forming apparatus assembling method for assembling an image forming apparatus supported on a side,
An image forming unit is formed by engaging one unit of the first unit or the second unit following the other unit having higher rigidity than the one unit,
An image forming apparatus assembling method, wherein the image forming unit is supported on the main body side.   The image forming apparatus assembling method according to claim 8, wherein the first unit and the second unit are detachable from each other.   The image forming apparatus assembling method according to claim 8, wherein the image forming unit is detachable from the main body side.

Images