JP6494295B2 - Image forming apparatus and cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus that uses an electrophotographic system or the like that forms an image by visualizing an electrostatic image formed on an image carrier with a developer, and a cartridge that can be inserted into and removed from the image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a printer, a facsimile machine, a copier, or a multifunction machine that forms an image on a recording material using an image forming process means is known. In the image forming apparatus, the image forming process means is singly or in combination as a unit, and can be inserted into and removed from the apparatus main body as a cartridge. Examples of the cartridge include a developing cartridge in which a developing sleeve and a conveying screw are unitized, and a drum cartridge in which a photosensitive drum, a charging roller, a photosensitive drum cleaner, and the like are unitized. The developing cartridge and the drum cartridge are mounted on the apparatus main body so that the developing sleeve and the photosensitive drum face each other with a predetermined distance therebetween.

  These cartridges are distributed as replacement parts, and replacement work is appropriately performed by the user. Therefore, for the purpose of protecting the surface of the photosensitive drum, the developing sleeve, etc., a protective cover is attached to the cartridge before the replacement work so as to cover the exposed surface of the photosensitive drum, for example. In this case, when replacing the cartridge, the cartridge needs to be inserted into the apparatus main body after the protective member is separated. However, if the protective member is separated before insertion, the photosensitive drum will be exposed, and the user may accidentally touch the photosensitive drum when inserting the cartridge into the main body of the apparatus, and the photosensitive drum may be damaged. There is. Therefore, an image forming apparatus has been proposed in which the protective member is removed to gradually expose the photosensitive drum as the cartridge is inserted into the apparatus body, thereby preventing the photosensitive drum from being damaged ( Patent Document 1).

JP 2002-132120 A

  By the way, for example, when the drum cartridge is inserted, the drum cartridge may be rattled and the photosensitive drum may come into contact with the developing sleeve in the apparatus main body and be damaged. Therefore, it is conceivable to provide a guide on the apparatus main body side to reduce the play of the drum cartridge at the time of insertion while ensuring the space between the photosensitive drum and the developing sleeve, and to restrict the movement of the drum cartridge by this guide. . In this case, the drum cartridge is positioned and mounted on the apparatus main body while being regulated by the guide. However, if there is no play (play) between the guide and the drum cartridge, the drum cartridge can be attached to the apparatus main body in a twisted state, and therefore, the developing sleeve and the photosensitive drum are arranged close to each other at a predetermined interval. It becomes difficult.

  The present invention has been made in view of the above problems, and provides an image forming apparatus and a cartridge that do not damage the photosensitive drum and the developing sleeve when attaching and detaching the cartridge and that can be easily attached to the apparatus main body. Objective.

The image forming apparatus according to the present onset Ming, a drum cartridge having a photosensitive drum, and the drum cartridge mounted is inserted from the opening formed in the front side surface of the apparatus main body at a predetermined position in the apparatus main body A developing unit having a developing roller that carries toner for developing the electrostatic latent image formed on the photosensitive drum, and protrudes in a direction intersecting the direction in which the drum cartridge is inserted, A ridge provided on the drum cartridge along the insertion direction, and the drum cartridge inserted into the opening and moving in the insertion direction to guide the drum cartridge to the predetermined position on the front side of the apparatus main body. A recess provided in the apparatus main body, into which the protruding portion is inserted, and a downstream side of the protruding portion in the insertion direction is a front side. Rather than when inserted into the recess and fitted, the protruding portion moves toward the predetermined position, and the central portion of the protruding portion in the insertion direction is fitted into the recessed portion. The protrusion in the insertion direction is such that the gap between the surface of the developing roller and the surface of the photosensitive drum is wider when the protrusion is in contact with the developing unit side of the protrusion. The center part of the strip part protrudes toward the developing unit side from the downstream side of the projection part in the insertion direction .

The image forming apparatus according to the present onset Ming, a drum cartridge having a photosensitive drum, and the drum cartridge mounted is inserted from the opening formed in the front side surface of the apparatus main body at a predetermined position in the apparatus main body A developing unit having a developing roller that carries toner for developing the electrostatic latent image formed on the photosensitive drum, and protrudes in a direction intersecting the direction in which the drum cartridge is inserted, A ridge provided on the drum cartridge along the insertion direction, and the drum cartridge inserted into the opening and moving in the insertion direction to guide the drum cartridge to the predetermined position on the front side of the apparatus main body. A recess provided in the apparatus main body and into which the protruding portion is inserted, and a central portion of the protruding portion in the insertion direction is In order to prevent the photosensitive drum and the developing roller from coming into contact with each other while the drum cartridge is moved toward the predetermined position after being inserted into the opening, the drum cartridge protrudes toward the developing unit, and the protrusion in the inserting direction. The downstream end of the part has a narrower width in a direction intersecting each of the insertion direction and the protruding direction of the protrusion than the center part .

A drum cartridge according to the present invention includes a photosensitive drum that is inserted from an opening formed on the front side of an apparatus main body of an image forming apparatus including a developing unit having a developing roller and is mounted at a predetermined position in the apparatus main body. An insertion direction that is inserted into the opening and is fitted into a recess provided on the upstream side of the apparatus main body in the insertion direction so as to move along the insertion direction to the predetermined position. Than the time when the downstream side of the protrusion in the insertion direction is inserted and fitted into the recess, and the protrusion is thereafter The ridge portion moves when moving toward the predetermined position in a state where the ridge portion is fitted to the concave portion, and the central portion of the ridge portion in the insertion direction is fitted to the concave portion. The central portion of the protruding portion in the insertion direction is the developing unit so that the distance between the surface of the developing roller and the surface of the photosensitive drum when the developing unit side is in contact with the concave portion is wide. It protrudes toward the side .

Drum cartridge according to the present onset Ming is inserted from the opening formed on the front side of the apparatus body of the image forming apparatus having a developing unit having a developing roller, it is mounted at a predetermined position in the apparatus main body, the photosensitive drum A drum cartridge having the above structure, which is inserted into the opening and fits into a recess provided on the upstream side of the apparatus main body in the insertion direction so as to move along the insertion direction to the predetermined position. A projecting portion extending in a direction intersecting the direction and extending in the inserting direction, and a downstream end of the projecting portion in the inserting direction is the photosensitive drum while the drum cartridge is moving toward the predetermined position. And the developing roller to prevent contact with the developing roller in the insertion direction that restricts the movement of the drum cartridge toward the developing unit. That than the central portion of the ridges, the direction of width intersecting the respective protruding direction of the insertion direction as the ridges are narrow, it is characterized.

  According to the present invention, it is possible to easily attach the cartridge to the apparatus main body without damaging an image forming member used for image formation when the cartridge is attached or detached.

1 is an external perspective view showing an image forming apparatus according to an embodiment of the present invention, with a front cover being opened. FIG. 2 is an external perspective view showing the image forming apparatus in a state where an inner cover and a small cover are opened. 1 is a schematic diagram illustrating a configuration of an image forming apparatus. FIG. 3 is an external perspective view showing an image forming unit. Sectional drawing which shows an image forming part. FIG. 3 is a cross-sectional view illustrating an image forming unit in a separated state. The perspective view which looked at the drum cartridge from the insertion direction back side. The enlarged view which expanded a part of apparatus main body frame and was seen from the insertion direction back side. The perspective view which shows the apparatus main body frame for demonstrating a guide member. The perspective view which shows a guide member. The enlarged view which expands and shows a part of guide member. The perspective view which shows a rail member. Sectional drawing which shows a rail member. FIG. 4 is a diagram illustrating a positional relationship between a drum cartridge and a developing cartridge. FIG. 3 is a top view showing the drum cartridge of the first embodiment. The schematic diagram which shows a guide rib. It is a figure which shows a drum cartridge, (a) is an insertion direction back | inner side, (b) is an insertion direction intermediate part, (c) is sectional drawing which shows an insertion direction near side. It is a figure explaining insertion of a drum cartridge, (a) is the perspective view which shows the time of the insertion start, (b) in the middle of insertion, and (c) at the time of completion of insertion. It is a figure explaining the positional relationship of a drum cartridge and a developing cartridge, (a) is a cross-sectional view showing the time of starting insertion, (b) during the insertion, and (c) when the insertion is completed. The schematic diagram which shows another Example of a guide rib. It is a figure explaining the positional relationship of a guide rib and a guide groove, (a) is a schematic diagram which shows the time of an insertion start, and (b) at the time of completion of insertion. The top view which shows the drum cartridge of 2nd Embodiment. FIG. 4 is a schematic diagram showing a cartridge guide. The figure explaining the positional relationship of a drum cartridge and a developing cartridge at the time of insertion. It is a figure explaining the positional relationship of a cartridge guide and a main body guide rib, (a) is a schematic diagram which shows the time of an insertion start, (b) in the middle of insertion, (c) at the time of completion of insertion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 shows an image forming apparatus according to an embodiment of the present invention with a front cover 1 opened. FIG. 2 shows a state where the inner cover 2 and the small cover 3 of the image forming apparatus 100 are further opened. As shown in FIG. 1, the image forming apparatus 100 includes a front cover 1 that can be opened and closed on the front side (the front side in the figure) of the apparatus main body 10, and the front side of the apparatus main body 10 when the front cover 1 is opened. An exposed inner cover 2 and a plurality of small covers 3 are provided. The inner cover 2 is formed with a plurality of attachment openings, and the toner cartridge 221 can be attached to or removed from the apparatus main body 10 from the attachment openings.

  As shown in FIG. 2, the inner cover 2 is formed to be removable from the apparatus main body 10. By removing the inner cover 2, it is possible to access the inside of the apparatus body 10 from the outside of the apparatus body 10. On the other hand, the small cover 3 is formed to be openable and closable in the opening 10a on the front side of the apparatus main body 10, and when the small cover 3 is opened, an image forming section (see FIG. 3 described later) housed in the apparatus main body is opened. It is exposed from the part 10a. Here, four image forming units including the developing cartridge 220 and the drum cartridge 270 are arranged in the horizontal direction in the center of the apparatus. The developing cartridge 220 and the drum cartridge 270 are mounted on the apparatus main body 10 and operate by receiving driving force transmission, power supply, and the like from the apparatus main body 10. In general, the developing cartridge 220 and the drum cartridge 270 need to be replaced whenever necessary because they have a shorter durable life than other image forming process means (for example, a fixing device) constituting the image forming apparatus 100. Therefore, the developing cartridge 220 and the drum cartridge 270 are provided so as to be detachable from the apparatus main body 10 with the front cover 1 and the small cover 3 being opened (see arrow G in FIG. 2). As will be described in detail later, a rail rib 242 (see, for example, FIG. 5) extends in the insertion direction on the drum cartridge 270, while a rail member 240 (see, for example, FIG. 11) extends in the insertion direction on the apparatus body 10. It is extended. When the rail rib 242 and the rail member 240 are engaged, the drum cartridge 270 can be attached to and detached from the apparatus main body 10 so as to be slidable.

[Image forming apparatus]
The configuration of the image forming apparatus 100 will be described with reference to FIG. FIG. 3 is a schematic diagram showing the configuration of the image forming apparatus according to the embodiment of the present invention, and shows a color image forming apparatus using an electrophotographic system. An image forming apparatus 100 shown in FIG. 3 is a so-called intermediate transfer tandem apparatus in which four color image forming portions UY, UM, UC, and UK are arranged in the apparatus main body 10 so as to face the intermediate transfer belt 260. That is, four sets of image forming portions UY, UM, UC, UK of yellow (Y), magenta (M), cyan (C), and black (BK) are arranged. However, the number of colors is not limited to four, and the color arrangement order is not limited to this. Each of these image forming units UY, UM, UC, UK includes a developing cartridge 220 and a drum cartridge 270.

  A recording material conveyance process of the image forming apparatus 100 will be described. The recording material S is stored so as to be stacked in a recording material storage (cassette) 4 and is fed to the transport path 20 in accordance with the image forming timing. The recording material S fed from the recording material storage (cassette) 4 is sent to the secondary transfer portion T2 after skew correction and timing correction are performed. The secondary transfer portion T2 is a transfer nip portion formed by the opposing secondary transfer inner roller 261 and the secondary transfer outer roller 21, and applies a predetermined pressure and electrostatic load bias on the recording material S. The toner image is adsorbed to the toner.

  A process of forming an image sent to the secondary transfer portion T2 at the same timing as the conveyance process of the recording material S to the secondary transfer portion T2 described above will be described. First, the image forming units UY to UK will be described. Since the configurations of the image forming units UY to UK for each color are basically the same except for the color of the toner, a black (BK) image will be representatively described below. The formation unit UK will be described. The image forming unit UK includes a drum cartridge 270 mainly having a photosensitive drum 210 as an image forming member, and a developing cartridge 220 mainly having a developing sleeve 211 as an image forming member. The drum cartridge 270 and the developing cartridge 220 will be described later.

  The surface of the rotationally driven photosensitive drum 210 is uniformly charged in advance by a charging roller 212, and then an electrostatic latent image is formed by the exposure unit 12 that is driven based on a signal of image information. Next, the electrostatic latent image formed on the photosensitive drum 210 is visualized through toner development by the developing sleeve 211. Thereafter, a predetermined pressing force and an electrostatic load bias are applied by the primary transfer device 5 disposed so as to face the image forming unit UK and the intermediate transfer belt 260, and the toner image formed on the photosensitive drum 210 is intermediately transferred. Primary transfer is performed on the transfer belt 260. As the developer, a two-component developer in which toner and a magnetic carrier are mixed is used, and the developer is supplied from the toner cartridge 221 set in the image forming unit UK to the developing cartridge 220 through a toner supply unit (not shown).

  The intermediate transfer belt 260 is an endless belt that is stretched by various rollers such as a secondary transfer inner roller 261, a driven roller 262, and a tension roller 263, and is rotationally driven in the direction of arrow R1 in the drawing. Here, the secondary transfer inner roller 261 also serves as a driving roller for driving the intermediate transfer belt 260. The image forming processes of the respective colors processed in parallel by the image forming units UY to UK described above are performed at the timing of sequentially superimposing on the upstream color toner image that has been primarily transferred onto the intermediate transfer belt 260. As a result, a full-color toner image is finally formed on the intermediate transfer belt 260 and conveyed to the secondary transfer portion T2.

  As described above, with the conveyance process and the image forming process described above, the timing of the recording material S and the full-color toner image coincide with each other in the secondary transfer portion T2, and the secondary transfer is performed. Thereafter, the recording material S is conveyed to the fixing device 30 and the toner image is melted and fixed on the recording material S with a predetermined pressure and heat. The recording material S on which the image has been fixed in this manner is discharged onto the paper discharge tray 312 by the paper discharge roller 22.

  Next, the developing cartridge 220 and the drum cartridge 270 will be described with reference to FIGS. As shown in FIG. 4, the image forming unit UK (UY to UC) is configured by combining a developing cartridge 220 and a drum cartridge 270 that are independently formed. The developing cartridge 220 and the drum cartridge 270 are mounted on the apparatus main body 10 (see FIG. 1) so that the developing sleeve 211 and the photosensitive drum 210 face each other with a predetermined distance therebetween. However, in the following, in order to facilitate understanding of the description, it is assumed that the developing cartridge 220 has already been attached to the apparatus main body 10.

[Developer cartridge]
As shown in FIGS. 5 to 6, the developing cartridge 220 includes a developing sleeve 211 as a developer carrying member rotatably supported in the developing container 110, a cleaning blade 111, a conveying screw 112, and a stirring screw 113. Etc. The developing container 110 contains a two-component developer (hereinafter simply referred to as a developer) composed of a nonmagnetic toner and a magnetic carrier. The interior of the developing container 110 is divided into two chambers (a developing chamber and a stirring chamber) by a partition 114, and the developing chamber and the stirring chamber are connected at both ends in the longitudinal direction of the developing container 110.

  A conveying screw 112 is rotatably supported in the developing chamber, and a stirring screw 113 is rotatably supported in the stirring chamber. The conveying screw 112 and the agitation screw 113 are arranged in parallel so that they are adjacent to each other and their respective rotation axes are in the same direction as the rotation axis of the developing sleeve 211. The developer is circulated and conveyed between the developing chamber and the agitating chamber as the conveying screw 112 and the agitating screw 113 are driven. The developing sleeve 211 carries and conveys the developer supplied from the developing chamber. The cleaning blade 111 is provided at a position close to the surface of the developing sleeve 211, and forms a thin layer of developer on the surface of the developing sleeve 211.

[Drum cartridge]
On the other hand, as shown in FIGS. 5 to 6, the drum cartridge 270 includes a photosensitive drum 210 as an image carrier that is rotatably supported by a housing 213 as a housing, a charging roller 212, a drum cleaning blade 216, and the like. It is composed of The housing 213 is disposed such that a portion facing the developing sleeve 211 of the developing cartridge 220 is opened when the housing 213 is mounted, and a part of the photosensitive drum 210 is exposed from the opened portion. . The charging roller 212 uniformly charges the surface of the photosensitive drum 210 that is driven to rotate. The photosensitive drum 210 is connected to a driving source (not shown) of the apparatus main body 10 and is rotated by a driving force transmitted from the driving source. On the other hand, the charging roller 212 is pressed by the photosensitive drum 210 and rotates following the photosensitive drum 210. After the photosensitive drum 210 is charged by the charging roller 212, an electrostatic latent image is formed by the exposure unit 12 provided in the apparatus main body 10. The electrostatic latent image formed on the photosensitive drum 210 is visualized through toner development by the developing sleeve 211. Thereafter, the toner image formed on the photosensitive drum 210 is transferred to a recording material or the like. The drum cleaning blade 216 removes transfer residual toner remaining on the photosensitive drum 210 because it is not transferred.

  Incidentally, the photosensitive drum 210, the charging roller 212, and the drum cleaning blade 216 are deteriorated as the image is formed. For this reason, the drum cartridge 270 needs to be appropriately replaced according to the cumulative number of prints of the recording material S on which an image has been formed. Therefore, the drum cartridge 270 is configured to be insertable / removable with respect to the apparatus main body 10. For example, the drum cartridge 270 shown in FIG. 4 can be inserted into the apparatus main body 10 so as to be slid in the longitudinal direction (see arrow X in the figure) separately from the developing cartridge 220, and can be removed from the apparatus main body 10. It is. The insertion direction (longitudinal direction) of the drum cartridge 270 is the same direction as the rotation axis direction of the photosensitive drum 210, and is also the same direction as the rotation axis direction of the developing sleeve 211 of the developing cartridge 220.

  As shown in FIG. 5, the drum cartridge 270 is mounted on the apparatus main body 10 with the developing sleeve 211 and the photosensitive drum 210 being close to each other at a predetermined interval. However, if the drum cartridge 270 can be inserted into and removed from the apparatus body 10 while the developing sleeve 211 and the photosensitive drum 210 are close to each other at a predetermined interval, the photosensitive drum 210 and the developing sleeve 211 come into contact with each other at the time of insertion and removal. May be scratched. In order to prevent this, as shown in FIG. 6, it is conceivable that the drum cartridge 270 can be inserted into and removed from the apparatus main body 10 after the drum cartridge 270 and the developing cartridge 220 are separated from each other. In this way, a sufficient space can be secured between the photosensitive drum 210 and the developing sleeve 211 so that they do not come into contact with each other, and the photosensitive drum 210 and the developing sleeve 211 are hardly damaged when being inserted and removed. However, in order to do this, a space sufficient to sufficiently separate the developing cartridge 220 from the drum cartridge 270 must be ensured in the apparatus main body 10, and this increases the size of the apparatus and is difficult to employ.

  Accordingly, a drum cartridge 270 that can be inserted into and removed from the apparatus main body 10 without causing the photosensitive drum 210 and the developing sleeve 211 to slide without causing the drum cartridge 270 and the developing cartridge 220 to be separated greatly from each other, and an image forming apparatus are proposed. .

<First Embodiment>
The first embodiment will be described with reference to FIGS. 5 to 19C. As shown in FIGS. 5 and 6, the drum cartridge 270 is integrally provided with a guide rib 214 as a protruding portion or a fitted portion in the housing 213. The drum cartridge 270 is integrally provided with a rail rib 242 as an engaging portion on the housing 213. The guide rib 214 can be engaged with a guide member 218 as a fitting portion provided in the apparatus main body 10, and the rail rib 242 can be engaged with a rail member 240 (see FIG. 9 described later) provided in the apparatus main body 10. Provided at different positions. In the present embodiment, as an example, the rail rib 242 is provided on the bottom surface of the drum cartridge 270 in an inserted state. The guide rib 214 is provided at a position different from the bottom surface portion where the rail rib 242 is provided (here, on the upper side of the side surface portion) so as to protrude perpendicularly to the bottom surface portion and upward on the opposite side of the bottom surface portion.

  The guide ribs 214 and the rail ribs 242 extend so as to extend in parallel with each other in the longitudinal direction of the photosensitive drum 210, that is, in the insertion direction of the drum cartridge 270. When the drum cartridge 270 is inserted, the guide rib 214 is slidably fitted to the guide member 218, and the rail rib 242 is slidably engaged to the rail member 240. If the guide rib 214 and the rail rib 242 are provided integrally with the housing 213, the number of parts can be reduced and it is advantageous from the viewpoint of cost. However, the present invention is not limited to this, and the guide rib 214 and the rail rib 242 may not be integrally formed.

  As shown in FIG. 7, the drum cartridge 270 is provided with positioning pins 217a and 217b as positioning portions on the mounting side with respect to the apparatus main body 10 on the back side in the insertion direction (see arrow X in the figure) and on the front side in the insertion direction. It has been. When the insertion of the drum cartridge 270 is completed, the positioning pins 217a and 217b are positioned on the rear side in the insertion direction of the main body frame 230 shown in FIG. 8 and the positioning hole provided on the front side in the insertion direction of the main body frame 230. And 231b. Thus, when mounted, the drum cartridge 270 is positioned in the width direction intersecting the insertion direction, and is positioned at a predetermined position in the apparatus main body 10 with the photosensitive drum 210 maintained at a predetermined interval with respect to the developing sleeve 211.

[Guide member]
Here, the guide member 218 fitted to the guide rib 214 and the rail member 240 engaged with the rail rib 242 will be described with reference to FIGS. 9 to 13. First, the guide member 218 will be described. As shown in FIG. 9, the guide member 218 is provided on the main body frame 230 on the front side (front side in the insertion direction) of the opening 10a (see FIG. 1) of the apparatus main body 10 provided with the small cover 3 (see FIG. 1). It is done. As shown in FIG. 10, in this embodiment, the guide member 218 is provided with four guide grooves 219 each having a predetermined interval in the width direction intersecting the insertion direction. The guide grooves 219 serving as the recesses are fitted to the guide ribs 214 of the respective drum cartridges 270 of yellow, magenta, cyan, and black. As shown in FIG. 11, in this embodiment, a guide groove 219 having a guide width L is formed in a groove shape that is recessed upward in the vertical direction with respect to the bottom surface portion. That is, the guide groove 219 is formed in a groove shape into which the guide rib 214 formed in a protruding shape can be inserted and fitted when the drum cartridge 270 is inserted. Note that the position of the guide rib 214 that fits into the guide groove 219 during insertion varies depending on the amount of insertion of the drum cartridge 270 into the apparatus main body 10.

[Rail member]
The rail member 240 will be described. As shown in FIG. 9, the rail member 240 as a guide member is provided immediately below the mounting position of the drum cartridge 270 in the main body frame 230. As shown in FIGS. 12 and 13, the rail member 240 has a rail groove 241 extending in the insertion direction (longitudinal direction). When the drum cartridge 270 is inserted, the rail rib 242 is engaged with the rail groove 241. The drum cartridge 270 is guided to a predetermined position in the apparatus main body 10 by the rail member 240, and the positioning pins 217a and 217b described above are fitted into the positioning holes 231a and 231b (see FIGS. 7 and 8). The rail member 240 also functions as a support base that supports the drum cartridge 270 from below in the apparatus main body 10.

  By the way, it is better to secure a predetermined gap (called play or play) between the rail groove 241 and the rail rib 242 in order to smoothly insert the drum cartridge 270 into the apparatus main body 10. However, in that case, as shown in FIG. 14, the drum cartridge 270 tends to tilt toward the developing cartridge 220 (in the direction of arrow M in the figure) during insertion. Therefore, the possibility that the photosensitive drum 210 and the developing cartridge 220 approach and come into contact with each other at the time of insertion increases, and if these actually contact, the photosensitive drum 210 and the developing cartridge 220 are damaged. Therefore, in this embodiment, the guide rib 214 is provided on the drum cartridge 270 side, and the guide member 218 is provided on the apparatus main body 10 side. Thus, the drum cartridge 270 is guided by the rail groove 241 and the rail rib 242, and the drum cartridge 270 is guided by the guide rib 214 and the guide member 218. The inclination of the developing cartridge 220 is restricted by changing the fitting mode of the guide rib 214 and the guide member 218 depending on the amount of insertion of the drum cartridge 270 into the apparatus main body 10. This will be described below.

  As shown in FIGS. 15 to 17, in this embodiment, the thickness of the guide rib 214 (width in the width direction intersecting the insertion direction) is varied with respect to the insertion direction. Here, the first rib portion 214a on the back side in the insertion direction (downstream end portion in the insertion direction), the third rib portion 214c on the near side in the insertion direction (upstream end portion in the insertion direction), and the other intermediate portions in the insertion direction in the other direction. The two rib portions 214b have different thicknesses. For example, when the first rib portion 214a is formed to a thickness (t1), the third rib portion 214c may be formed to the same thickness (t1), but the second rib portion 214b is related to the thickness (t1). Is formed to a thickness (t2) where “t1 <t2”. That is, the guide rib 214 is formed such that the thickness of the second rib portion 214b at the intermediate portion in the insertion direction is thicker than the thickness of the first rib portion 214a and the third rib portion 214c on the back side in the insertion direction and on the near side in the insertion direction. Is done. In other words, the guide rib 214 includes, in order from the back in the insertion direction, a first rib portion 214a having a predetermined thickness, a second rib portion 214b formed to be thicker than the first rib portion 214a, and a second rib portion 214b. And a third rib portion 214c formed thinner than the rib portion 214b.

  The second rib portion 214b is formed to have a thickness slightly smaller than the guide width L (see FIG. 11) of the guide groove 219 of the guide member 218. That is, the second rib portion 214b is formed to a thickness that causes a slight gap between the second rib portion 214b and the guide groove 219. On the other hand, the first rib portion 214a and the third rib portion 214c only have to be thinner than the second rib portion 214b. For example, the first rib portion 214a and the third rib portion 214c may be formed to be less than half the thickness of the second rib portion 214b. In addition, the first rib portion 214a and the third rib portion 214c are not limited to be formed to have the same thickness, and may be formed to have different thicknesses as long as they are thinner than the second rib portion 214b. Thereby, when the guide rib 214 and the guide member 218 are fitted, the second rib portion is larger than the gap formed between the guide groove 219 and the first rib portion 214a or the third rib portion 214c. A gap generated between the guide groove 219 and the guide groove 219 when fitted by 214b is narrowed. The range of the second rib portion 214b is desirably formed so as to include at least the range where the toner image on the photosensitive drum 210 is formed.

  The manner in which the guide rib 214 and the guide member 218 are fitted in the process of inserting the drum cartridge 270 will be described with reference to FIGS. 18 (a) to 19 (c). At the start of insertion of the drum cartridge 270 shown in FIG. 18A, the first rib portion 214a of the guide rib 214 is fitted into the guide groove 219 of the guide member 218, as shown in FIG. In this case, a relatively large gap is secured between the first rib portion 214a and the guide groove 219 as compared with the case where the second rib portion 214b is fitted in the guide groove 219. 270 is easily inserted into the apparatus main body 10. The drum cartridge 270 is not inserted into the apparatus main body 10 to such an extent that the photosensitive drum 210 and the developing sleeve 211 can be brought into contact with each other. Therefore, although the drum cartridge 270 can be tilted toward the developing cartridge 220, the photosensitive drum 210 and the developing sleeve 211 cannot come into contact even if tilted toward the developing cartridge 220. Accordingly, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  During insertion of the drum cartridge 270 shown in FIG. 18B, the second rib portion 214b of the guide rib 214 is fitted into the guide groove 219 of the guide member 218, as shown in FIG. 19B. In this case, the drum cartridge 270 is inserted into the apparatus main body 10 up to an insertion amount that allows the photosensitive drum 210 and the developing sleeve 211 to come into contact with each other. In general, the housing 213 of the drum cartridge 270 is easily bent by an external force that acts in accordance with the engagement between the guide rib 214 and the guide groove 219. In particular, when the guide rib 214 is fitted to the guide member 218 near the intermediate portion in the insertion direction of the drum cartridge 270, the housing 213 is likely to be greatly bent. Therefore, it can be said that the state in which the drum cartridge 270 is inserted into the apparatus main body 10 to the vicinity of the intermediate portion in the insertion direction is a state in which the photosensitive drum 210 and the developing sleeve 211 are easily in contact with each other.

  In the present embodiment, as described above, the second rib portion 214b is formed to have a thickness slightly smaller than the guide width L of the guide groove 219. According to this, when the second rib portion 214b and the guide groove 219 are fitted, only a slight gap is generated between the second rib portion 214b and the guide groove 219. It becomes difficult to move to the developing cartridge 220 side. Further, as the thickness of the guide rib 214 increases, more specifically, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 is increased by the difference in thickness between the second rib portion 214b and the first rib portion 214a (for example, t2-t1). Secured. Therefore, even if the housing 213 is bent, the drum cartridge 270 can be inserted into the apparatus main body 10 without the photosensitive drum 210 and the developing sleeve 211 contacting each other. In this way, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  When the insertion of the drum cartridge 270 shown in FIG. 18C is completed, the third rib portion 214c of the guide rib 214 is fitted into the guide groove 219 of the guide member 218 as shown in FIG. 19C. In this case, a relatively large gap is secured between the third rib portion 214c and the guide groove 219 as compared with the case where the second rib portion 214b is fitted in the guide groove 219. Even in this case, the drum cartridge 270 can be inclined toward the developing cartridge 220 as in the case where the first rib portion 214a is fitted in the guide groove 219. However, even if it is inclined toward the developing cartridge 220, the inclination is restricted by the guide rib 214 and the guide member 218, and the photosensitive drum 210 and the developing sleeve 211 are difficult to contact. Accordingly, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  As already described, when the insertion of the drum cartridge 270 is completed, the positioning pins 217a and 217b are fitted into the positioning holes 231a and 231b provided in the main body frame 230 (see FIGS. 7 and 8). At this time, since the drum cartridge 270 can be tilted toward the developing cartridge 220, the positioning pins 217a and 217b are inserted into the positioning holes 231a and 231b in a state where the drum cartridge 270 is twisted on the back side in the insertion direction and the front side in the insertion direction. There is no mating. That is, in this embodiment, the drum cartridge 270 cannot be mounted in a twisted state. As a result, the drum cartridge 270 can be correctly mounted on the apparatus main body 10 with the photosensitive drum 210 approaching the developing sleeve 211 at a predetermined interval.

  As described above, the groove-shaped guide member 218 is provided on the apparatus main body 10 side, and the projecting-shaped guide rib 214 to be fitted to the guide member 218 is provided on the drum cartridge 270 side. The guide rib 214 is formed such that the thickness of the second rib portion 214b at the intermediate portion in the insertion direction is thicker than the thickness of the first rib portion 214a and the third rib portion 214c on the back side in the insertion direction and on the near side in the insertion direction. The Further, the second rib portion 214 b is formed to have a thickness slightly smaller than the groove width of the guide groove 219 of the guide member 218. According to this, when the second rib portion 214b and the guide groove 219 are fitted, the drum cartridge 270 is difficult to move to the developing cartridge 220 side. Further, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 becomes wider. Therefore, the photosensitive drum 210 and the developing sleeve 211 cannot come into contact with each other when inserted into the apparatus main body 10. Accordingly, the drum cartridge 270 can be attached to the apparatus main body 10 without damaging the surfaces of the photosensitive drum 210 and the developing sleeve 211. Further, since the first rib portion 214a on the back side in the insertion direction is formed thinner than the second rib portion 214b, the drum cartridge 270 is easily inserted into the apparatus main body 10. Further, since the third rib portion 214c on the near side in the insertion direction is formed thicker than the second rib portion 214b, the photosensitive drum 210 is brought close to the developing sleeve 211 at a predetermined interval when the insertion is completed. It can be installed correctly.

  The shape of the guide rib 214 is not limited to the shape shown in FIG. Therefore, another shape of the guide rib 214 will be described with reference to FIGS. 20 to 21B. As with the guide rib 214 shown in FIG. 16, the guide rib 214A shown in FIG. 20 has a first rib portion 214a on the back side in the insertion direction, a third rib portion 214c on the near side in the insertion direction, and other intermediate portions in the insertion direction. The second rib portion 214b has a different thickness. Even in this case, for example, when the first rib portion 214a is formed with the thickness (t1), the third rib portion 214c is formed with the same thickness (t1), but the second rib portion 214b has the thickness (t1). Is formed to a thickness (t2) that satisfies “t1 <t2”. The second rib portion 214b is formed to have a thickness slightly smaller than the guide width L (see FIG. 11) of the guide groove 219 of the guide member 218.

  As can be understood by comparing FIG. 16 and FIG. 20, the guide rib 214 </ b> A is different from the guide rib 214 in the arrangement position of the first rib portion 214 a and the third rib portion 214 c with respect to the second rib portion 214 b. That is, in the guide rib 214A, the first rib portion 214a is disposed on the side close to the developing cartridge 220 (the left side in FIG. 20). In this case, as compared with the guide rib 214, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 is easily secured in a state where the first rib portion 214a is fitted in the guide groove 219. Therefore, the guide rib 214 </ b> A is less likely to be scratched on the surface of the photosensitive drum 210 and the developing sleeve 211 than the guide rib 214. When the insertion of the drum cartridge 270 is started, as shown in FIG. 21A, a gap is formed between the guide rib 214A and the guide groove 219, so that the drum cartridge 270 is easily inserted into the apparatus main body 10.

  In the guide rib 214A, the third rib portion 214c is disposed at a position offset from the first rib portion 214a with the second rib portion 214b interposed therebetween. Here, as shown in FIG. 21B, the third rib portion 214c is disposed at a position where a gap is formed between the guide rib 219 on both side surfaces of the guide rib 214A in a state where the third rib portion 214c is fitted to the guide groove 219. Yes. Even in this case, as compared with the guide rib 214, even when the third rib portion 214c is fitted in the guide groove 219, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 is easily secured. Therefore, the guide rib 214A is less likely to be scratched on the surfaces of the photosensitive drum 210 and the developing sleeve 211.

  Further, if gaps may be formed on both side surfaces of the guide rib 214A, the positioning pins 217a and 217b are fitted into the positioning holes 231a and 231b while the drum cartridge 270 is twisted when the insertion of the drum cartridge 270 is completed. There is nothing. That is, even with the guide rib 214A, the drum cartridge 270 cannot be mounted in a twisted state. Therefore, the drum cartridge 270 is attached to the apparatus main body 10 with the photosensitive drum 210 approaching the developing sleeve 211 at a predetermined interval. It can be installed correctly.

Second Embodiment
Next, 2nd Embodiment is described using FIG. 22 thru | or FIG.25 (c). In the first embodiment, the drum cartridge 270 is provided with the protruding guide rib 214, and the apparatus main body 10 is provided with the guide member 218 having the groove-shaped guide groove 219, whereas the second embodiment has an opposite configuration. . That is, the drum cartridge 270A is provided with a groove-shaped cartridge guide 246 as a groove portion, and the apparatus main body 10 is provided with a guide member 244 having a protruding main body guide rib 245 as a convex portion (see FIG. 24). Since other configurations are the same as those in the first embodiment, the same reference numerals are given and detailed descriptions thereof are omitted.

  As shown in FIG. 22, the drum cartridge 270A is integrally provided with a cartridge guide 246 as a fitted portion. The cartridge guide 246 is provided at a position where it can be fitted with a guide member 244 (see FIG. 24) as a fitting portion provided in the apparatus main body 10. The cartridge guide 246 extends so as to extend in the longitudinal direction of the photosensitive drum 210, that is, in the insertion direction of the drum cartridge 270A. When the drum cartridge 270A is inserted, the cartridge guide 246 is fitted to the guide member 244 so as to be slidable. If the cartridge guide 246 is provided integrally with the housing 213 (see FIG. 24), the number of parts can be reduced and it is advantageous from the viewpoint of cost. However, the present invention is not limited to this, and the cartridge guide 246 may not be integrally formed.

  As shown in FIG. 23, in this embodiment, the groove width of the cartridge guide 246 (width in the direction intersecting the insertion direction) is varied with respect to the insertion direction. Here, the first groove portion 246a on the back side in the insertion direction (downstream end portion in the insertion direction), the third groove portion 246c on the near side in the insertion direction (upstream end portion in the insertion direction), and the second groove portion in the other intermediate portion in the insertion direction. 246b has a different groove width. For example, when the first groove portion 246a is formed with the groove width (t4), the third groove portion 246c may be formed with the same thickness (t4), but the second groove portion 246b has a magnitude relationship with the groove width (t4). It is formed to a thickness (t3) that satisfies “t3 <t4”. That is, the cartridge guide 246 is formed so that the groove width of the second groove portion 246b at the intermediate portion in the insertion direction is narrower than the groove widths of the first groove portion 246a and the third groove portion 246c on the rear side in the insertion direction and the front side in the insertion direction. Is done.

  The second groove portion 246b is formed to have a groove width slightly larger than the width H (see FIG. 24) of the main body guide rib 245 of the guide member 244. That is, the second groove portion 246 b is formed to have a groove width that causes a slight gap between the second groove portion 246 b and the main body guide rib 245. The main body guide rib 245 is formed with a constant width in a direction intersecting the insertion direction. On the other hand, the first groove portion 246a and the third groove portion 246c only need to have a groove width wider than the groove width of the second groove portion 246b. For example, the first groove portion 246a and the third groove portion 246c may be formed to be twice or more the groove width of the second groove portion 246b. Further, the first groove portion 246a and the third groove portion 246c are not limited to be formed with the same groove width, and may be formed with different groove widths as long as they are wider than the groove width of the second groove portion 246b. When the cartridge guide 246 and the guide member 244 are fitted, when the second groove 246b is fitted rather than the gap generated between the cartridge guide 246 and the main body guide rib 245 when fitted with the first groove 246a or the third groove 246c. The gap between the main body guide ribs 245 is narrowed. The range of the second groove 246b is desirably formed so as to include at least the range where the toner image on the photosensitive drum 210 is formed.

  The manner in which the cartridge guide 246 and the guide member 244 are fitted in the process of inserting the drum cartridge 270A will be described with reference to FIGS. 25 (a) to 25 (c). When the insertion of the drum cartridge 270A is started, the first groove 246a of the cartridge guide 246 is fitted into the main body guide rib 245 of the guide member 244, as shown in FIG. In this case, since a relatively large gap is secured between the first groove 246a and the main body guide rib 245 as compared with the case where the second groove 246b is fitted to the main body guide rib 245, the drum cartridge 270A is It becomes easy to insert into the apparatus main body 10. In this case, the drum cartridge 270A can be tilted toward the developing cartridge 220, but the photosensitive drum 210 and the developing sleeve 211 cannot be in contact with each other. Accordingly, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  During the insertion of the drum cartridge 270A, the second groove 246b of the cartridge guide 246 is fitted into the main body guide rib 245 of the guide member 244, as shown in FIG. Thus, when the cartridge guide 246 is fitted to the guide member 244 in the vicinity of the intermediate portion in the insertion direction of the drum cartridge 270A, the housing 213 is likely to be greatly bent. Accordingly, when the drum cartridge 270 </ b> A is inserted into the apparatus main body 10 to the vicinity of the intermediate portion in the insertion direction, the photosensitive drum 210 and the developing sleeve 211 are likely to come into contact with each other.

  In the present embodiment, as described above, the second groove portion 246 b is formed to have a groove width slightly larger than the width H of the main body guide rib 245. According to this, when the second groove portion 246b and the main body guide rib 245 are fitted, there is only a slight gap between the second groove portion 246b and the main body guide rib 245, so that the drum cartridge 270A is a developing cartridge. It becomes difficult to move to the 220 side. Further, since the groove width of the cartridge guide 246 is narrowed, more specifically, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 is increased by the difference in thickness between the second groove portion 246b and the first groove portion 246a (for example, t4-t3). Widely secured. Therefore, even if the housing 213 is bent, the drum cartridge 270A can be inserted into the apparatus main body 10 without the photosensitive drum 210 and the developing sleeve 211 contacting each other. In this way, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  When the insertion of the drum cartridge 270A is completed, the third groove 246c of the cartridge guide 246 is fitted into the main body guide rib 245 of the guide member 244, as shown in FIG. In this case, a relatively large gap is secured between the third groove portion 246 c and the main body guide rib 245 as compared with the case where the second groove portion 246 b is fitted to the main body guide rib 245. Even in this case, the drum cartridge 270A can be tilted toward the developing cartridge 220 as in the case where the first groove 246a is fitted to the main body guide rib 245. However, even if tilted toward the developing cartridge 220, the tilt is regulated by the cartridge guide 246 and the guide member 244, and the photosensitive drum 210 and the developing sleeve 211 are difficult to contact. Accordingly, the surfaces of the photosensitive drum 210 and the developing sleeve 211 are hardly damaged.

  As already described, when the insertion of the drum cartridge 270A is completed, the positioning pins 217a and 217b are fitted into the positioning holes 231a and 231b provided in the main body frame 230 (see FIGS. 7 and 8). At this time, since the drum cartridge 270A can be tilted toward the developing cartridge 220, the positioning pins 217a and 217b are fitted in the positioning holes 231a and 231b in a state where the drum cartridge 270A is twisted on the back side in the insertion direction and the front side in the insertion direction. Cannot be combined. That is, in this embodiment, the drum cartridge 270A cannot be mounted in a twisted state. Accordingly, the drum cartridge 270A can be correctly mounted on the apparatus main body 10 in a state where the photosensitive drum 210 is brought close to the developing sleeve 211 at a predetermined interval.

  As described above, also in the second embodiment, the same effect as in the first embodiment can be obtained. That is, in the second embodiment, a protruding guide member 244 is provided on the apparatus main body 10 side, and a groove-shaped cartridge guide 246 to be fitted to the guide member 244 is provided on the drum cartridge 270A side. The cartridge guide 246 is formed so that the groove width of the second groove portion 246b at the intermediate portion in the insertion direction is narrower than the groove widths of the first groove portion 246a and the third groove portion 246c on the rear side in the insertion direction and the front side in the insertion direction. The Further, the second groove portion 246 b is formed to have a groove width slightly larger than the width of the main body guide rib 245 of the guide member 244. According to this, when the second groove 246b and the main body guide rib 245 are fitted, the drum cartridge 270A is difficult to move to the developing cartridge 220 side. Further, the distance between the axes of the photosensitive drum 210 and the developing sleeve 211 becomes wider. Therefore, the photosensitive drum 210 and the developing sleeve 211 cannot come into contact with each other when inserted into the apparatus main body 10. Accordingly, the drum cartridge 270 </ b> A can be mounted on the apparatus main body 10 without damaging the surfaces of the photosensitive drum 210 and the developing sleeve 211. Further, since the first groove portion 246a on the back side in the insertion direction is formed wider than the second groove portion 246b, the drum cartridge 270A is easily inserted into the apparatus main body 10. In addition, since the third groove 246c on the front side in the insertion direction is formed wider than the second groove 246b, when the insertion is completed, the photosensitive drum 210 is brought close to the developing sleeve 211 at a predetermined interval, so Can be installed.

  In each of the above-described embodiments, the case where the drum cartridge is inserted into the apparatus main body has been described as an example. However, the present invention is not limited to this. That is, the configuration according to the present embodiment can be applied to the developing cartridge 220 in the same manner, so that even when the developing cartridge 220 is inserted into the apparatus main body, the same effect as that of the drum cartridge described above can be obtained. it can. Further, the present invention can be similarly applied to a process cartridge in which a drum cartridge and a developing cartridge are integrated in advance.

DESCRIPTION OF SYMBOLS 10 ... Apparatus main body, 211 ... Developer carrier (image forming member, developing sleeve), 214 ... Projection part (fitting part, guide rib), 214a ... Downstream end part (first rib part) in insertion direction, 214b ... Insertion direction intermediate portion (second rib portion), 214c... Upstream end portion in insertion direction (third rib portion), 218 (244) .. fitting portion (guide member), 219... Recessed portion (guide groove), 210. Body (image forming member, photosensitive drum), 220 ... developing cartridge, 217a (217b) ... positioning part (positioning pin), 240 ... guide member (rail member), 242 ... engaging part (rail rib), 245 ... convex part ( Main body guide ribs), 246... Groove (fitted part, cartridge guide), 246a... Downstream end (first groove) in the insertion direction, 246b .. intermediate part (second groove) in the insertion direction, 246c. Samizo unit), 270 ... cartridge (drum cartridge), UY (UM, UC, UK) ... image forming unit

Claims (16)

A drum cartridge having a photosensitive drum, the drum cartridge being inserted from an opening formed on a side surface on the front side of the apparatus main body and mounted at a predetermined position in the apparatus main body, and a static electricity formed on the photosensitive drum An image forming apparatus comprising: a developing unit having a developing roller that carries toner for developing a latent image;
Projecting in a direction intersecting the direction in which the drum cartridge is inserted, and a ridge provided on the drum cartridge along the insertion direction;
A recess provided in the apparatus main body on the front side of the apparatus main body for guiding the drum cartridge that is inserted into the opening and moves in the insertion direction to the predetermined position; Prepared,
Rather than when the downstream side of the ridge portion in the insertion direction is inserted and fitted into the recess, the ridge portion moves toward the predetermined position thereafter, and the ridge portion in the insertion direction moves. The distance between the surface of the developing roller and the surface of the photosensitive drum when the developing unit side of the protrusion and the concave portion are in contact with each other when the central portion is fitted in the concave portion So that the central portion of the ridge portion in the insertion direction protrudes toward the developing unit rather than the downstream side of the ridge portion in the insertion direction.
An image forming apparatus. A drum cartridge having a photosensitive drum, the drum cartridge being inserted from an opening formed on a side surface on the front side of the apparatus main body and mounted at a predetermined position in the apparatus main body, and a static electricity formed on the photosensitive drum An image forming apparatus comprising: a developing unit having a developing roller that carries toner for developing a latent image;
Projecting in a direction intersecting the direction in which the drum cartridge is inserted, and a ridge provided on the drum cartridge along the insertion direction;
A recess provided in the apparatus main body on the front side of the apparatus main body for guiding the drum cartridge that is inserted into the opening and moves in the insertion direction to the predetermined position; Prepared,
The central portion of the protrusion in the insertion direction is arranged to prevent the development drum from contacting the developing drum during movement toward the predetermined position after the drum cartridge is inserted into the opening. Projecting toward the unit, the downstream end of the protrusion in the insertion direction has a narrower width in the direction intersecting each of the insertion direction and the protrusion direction of the protrusion than the center.
An image forming apparatus. The gap between the protrusion and the recess in the direction intersecting the insertion direction and the protrusion direction of the protrusion is such that the downstream end of the protrusion in the insertion direction is inserted into the recess. Narrower when the center of the ridge is fitted in the recess than when fitted,
The image forming apparatus according to claim 1, wherein: The downstream side of the central portion of the ridge portion in the insertion direction is inclined to the side where the photosensitive drum is disposed, and is continuous with the downstream side of the ridge portion in the insertion direction.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The drum cartridge includes positioning portions protruding in the insertion direction on one end side and the other end side of the drum cartridge in the insertion direction,
The position of the drum cartridge relative to the apparatus main body is determined by fitting the positioning portion into a hole formed in the apparatus main body at the predetermined position.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The upstream side of the protruding portion in the insertion direction has a narrower width in the direction intersecting the insertion direction and the protruding direction of the protruding portion than the center portion, and the drum cartridge is located at the predetermined position. Sometimes it is in a state fitted in the recess,
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The recess is provided at an edge of the opening;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The drum cartridge has an engaging portion provided along the insertion direction,
The apparatus main body includes a guide member that is provided along the insertion direction and guides the apparatus into the apparatus main body in a state where the drum cartridge is slidably supported by being engaged with the engaging portion at the time of insertion.
The image forming apparatus according to any one of claims 1 to 7, characterized in that. The downstream end of the central portion of the protrusion in the insertion direction is located downstream of the downstream end in the insertion direction of the region where the toner image is formed on the photosensitive drum in the insertion direction of the drum cartridge. And the upstream end of the central portion of the protrusion in the insertion direction is inserted into the drum cartridge more than the upstream end in the insertion direction of the region where the toner image is formed on the photosensitive drum. Located upstream in the direction,
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A drum cartridge having a photosensitive drum, which is inserted from an opening formed on the front side of an apparatus main body of an image forming apparatus including a developing unit having a developing roller, and is mounted at a predetermined position in the apparatus main body.
Projecting in a direction intersecting the insertion direction, fitted in a recess provided on the upstream side of the apparatus main body in the insertion direction in order to be inserted into the opening and move along the insertion direction to the predetermined position; Comprising a ridge extending in the insertion direction;
Rather than when the downstream side of the ridge portion in the insertion direction is inserted and fitted into the recess, the ridge portion moves toward the predetermined position in a state where the ridge portion is fitted into the recess, When the central portion of the protrusion in the insertion direction is fitted in the recess, the surface of the developing roller when the developing unit side of the protrusion and the recess are in contact with each other A central portion of the protruding portion in the insertion direction protrudes toward the developing unit so that a gap with the surface of the photosensitive drum is widened;
A drum cartridge characterized by that. A drum cartridge having a photosensitive drum, which is inserted from an opening formed on the front side of an apparatus main body of an image forming apparatus including a developing unit having a developing roller, and is mounted at a predetermined position in the apparatus main body.
Projecting in a direction intersecting the insertion direction, fitted in a recess provided on the upstream side of the apparatus main body in the insertion direction in order to be inserted into the opening and move along the insertion direction to the predetermined position; Comprising a ridge extending in the insertion direction;
The downstream end of the protrusion in the insertion direction is arranged so that the development of the drum cartridge is prevented in order to prevent the photosensitive drum and the developing roller from contacting each other while the drum cartridge is moving toward the predetermined position. The width in the direction intersecting each of the insertion direction and the protruding direction of the protruding portion is narrower than the central portion of the protruding portion in the inserting direction that restricts movement toward the unit,
A drum cartridge characterized by that. The gap between the protrusion and the recess in the direction intersecting the insertion direction and the protrusion direction of the protrusion is such that the downstream end of the protrusion in the insertion direction is inserted into the recess. Narrower when the center of the ridge is fitted in the recess than when fitted,
The drum cartridge according to claim 10 or 11, wherein The downstream side of the central portion of the ridge portion in the insertion direction is inclined to the side where the photosensitive drum is disposed, and is continuous with the downstream side of the ridge portion in the insertion direction.
The drum cartridge according to claim 10, wherein the drum cartridge is a drum cartridge. The drum cartridge includes positioning portions protruding in the insertion direction on one end side and the other end side of the drum cartridge in the insertion direction,
The position of the drum cartridge relative to the apparatus main body is determined by fitting the positioning portion into a hole formed in the apparatus main body at the predetermined position.
The drum cartridge according to any one of claims 10 to 13, wherein the drum cartridge is provided. The upstream side of the protruding portion in the insertion direction has a narrower width in the direction intersecting the insertion direction and the protruding direction of the protruding portion than the center portion, and the drum cartridge is located at the predetermined position. Sometimes it is in a state fitted in the recess,
The drum cartridge according to any one of claims 10 to 14, wherein: The downstream end of the central portion of the protrusion in the insertion direction is located downstream of the downstream end in the insertion direction of the region where the toner image is formed on the photosensitive drum in the insertion direction of the drum cartridge. And the upstream end of the central portion of the protrusion in the insertion direction is inserted into the drum cartridge more than the upstream end in the insertion direction of the region where the toner image is formed on the photosensitive drum. Located upstream in the direction,
The drum cartridge according to any one of claims 10 to 15, wherein:

Images