HK1131220B

HK1131220B - Electrophotographic image forming apparatus

Info

Publication number: HK1131220B
Application number: HK09110734.1A
Authority: HK
Inventors: Sakurai Hiromi; Noguchi Tomio; Imaizumi Chikara; Kawanami Takeo
Original assignee: 佳能株式会社
Priority date: 2007-05-23
Filing date: 2008-05-20
Publication date: 2011-11-04

Description

Electrophotographic image forming apparatus

Technical Field

The present invention relates to an electrophotographic image forming apparatus for forming an image on a recording medium.

The electrophotographic image forming apparatus forms an image on a recording medium by an electrophotographic image forming method. The electrophotographic image forming apparatus may include, for example, an electrophotographic copying machine, an electrophotographic printer (e.g., a laser printer or a light emitting diode printer), a facsimile machine, a word processor, or the like.

The process cartridge refers to a cartridge including at least a developer accommodating portion for accommodating a developer, which is detachably mountable to the main assembly of the electrophotographic image forming apparatus.

The process cartridge can be attached to or detached from the image forming apparatus by the user himself, so that maintenance of the image forming apparatus can be easily performed.

Background

As a method of replacing the process cartridge of the image forming apparatus, japanese laid-open patent application No. hei 8-220824 discloses a structure in which the process cartridge 30 is supported by a guide member 70 that is capable of expanding and contracting in two steps with respect to an ascending/descending plate 61 that moves back and forth, up and down in association with a side cover 80. The side cover 80 is opened to lift and move the process cartridge 30 from the image forming position (I) to the pulled-out position (II). Subsequently, the process cartridge 30 is directly pulled out to be selectively moved to a specific position including the stop position (III), thereby enabling attachment/detachment of each apparatus or member and jam processing.

The present invention further develops the above-described conventional structure.

Disclosure of Invention

A primary object of the present invention is to provide an electrophotographic image forming apparatus capable of improving usability in a process cartridge replaceable structure.

According to an aspect of the present invention, there is provided an electrophotographic image forming apparatus including:

a process cartridge including a developer accommodating portion for accommodating a developer;

a tray movable between a pulled-out position where the tray is located outside the apparatus main assembly and a pushed-in position where the tray is located inside the apparatus main assembly, the tray including a mounting portion for detachably mounting the process cartridge at the pulled-out position and a manual operation portion for facilitating pulling-out of the tray;

a pressing member for pressing the tray from a push-in position to a pull-out position;

a control member for controlling movement of the tray toward the pull-out position when the tray is located at the push-in position; and

a releasing portion for releasing control by the control member by operating the manual operation portion in a state where the tray is located at the push-in position,

wherein the tray is moved toward the pulled-out position by the urging member when the control by the control member is released.

According to another aspect of the present invention, there is provided an electrophotographic image forming apparatus including:

a tray movable between a drawn-out position where the tray is drawn out of the main assembly of the apparatus and a pushed-in position where the tray is pushed into the main assembly of the apparatus, the tray including a mounting portion for detachably mounting the process cartridge at the drawn-out position;

a pressing member for pressing the tray from a push-in position to a pull-out position; and

a control member for controlling movement of the tray toward the pull-out position when the tray is located at the push-in position; and is

Wherein the tray is moved toward the pulled-out position by being urged toward the pulled-out position by the urging member when the tray is at a predetermined position between the pushed-in position and the pulled-out position and excluding the pushed-in position.

These and other objects, features and advantages of the present invention will become apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 is an external perspective view of an image forming apparatus in embodiment 1 of the present invention.

Fig. 2 is a longitudinal sectional view of the image forming apparatus shown in fig. 1, viewed from the left side of the apparatus.

Fig. 3 is an external perspective view of the image forming apparatus shown in fig. 1 with the front door opened.

Fig. 4 is a longitudinal sectional view of the image forming apparatus shown in fig. 3 with the front door opened as viewed from the left side of the apparatus main assembly.

Fig. 5 is an external perspective view of the image forming apparatus shown in fig. 1, in which the cartridge tray of the image forming apparatus is further pulled out from the state shown in fig. 3.

Fig. 6 is a vertical sectional view of the image forming apparatus shown in fig. 4, as viewed from the left side of the apparatus, wherein the cartridge tray of the image forming apparatus is further pulled out from the state shown in fig. 4.

Fig. 7 is an external perspective view of the process cartridge viewed from the side where the process cartridge is driven.

Fig. 8 is an external perspective view of the process cartridge viewed from the side where the process cartridge is not driven.

Fig. 9 is a perspective view of the cartridge tray.

Fig. 10 is a perspective view of a portion of the relevant mechanism between the door and the tray holding member.

Fig. 11(a) to 11(c) are schematic views respectively showing the movement of the tray holding member in association with the rotational movement of the door.

Fig. 12 is an enlarged view of the via portion.

Fig. 13 is an enlarged view of a pin portion and a U-shaped groove portion as the tray control member.

Fig. 14, 15, 16(a) and 16(b) show interface portions adjacent to the process cartridge to release the application of pressure to the process cartridge and release the engagement with the process cartridge in association with the tray holding member, respectively.

Fig. 17 and 18 are perspective views each showing a first control member (position control means) for the tray.

Fig. 19(a) to 19(g) and 20(a) to 20(b) are sectional views respectively showing second control members for the tray.

Fig. 21(a), 21(b) and 21(c) are enlarged views showing first control members for the tray, respectively.

Fig. 22, 23, 24(a) and 24(b) are schematic views each showing a device for supplying electric power to the process cartridge.

Fig. 25 to 29 are schematic views each showing the constitution of the support member.

Fig. 30 is a schematic view showing members for assembling the main assembly frame of the image forming apparatus.

Fig. 31 is a schematic perspective view of the image forming apparatus in a state where the tray is moved from the pushed-in position to a predetermined position by the urging force of the urging member.

Detailed Description

Example 1

(general construction of image Forming apparatus)

The image forming apparatus of the present embodiment is an electrophotographic image forming apparatus to which a process cartridge is detachably mountable.

The general structure of the image forming apparatus will be described below with reference to fig. 1, 2, 7, and 8.

Fig. 1 is an external perspective view of the appearance of an image forming apparatus 100 in the present embodiment, and fig. 2 is a longitudinal sectional view of the image forming apparatus 100 viewed from the left side of the apparatus. The image forming apparatus is a full-color laser printer based on four colors using an electrophotographic method. That is, the image forming apparatus forms an image on a recording medium (sheet) based on an electric picture (image) signal input from an external host apparatus (not shown) such as a personal computer, an image reader, a transmitting facsimile machine, or the like.

In the following description, the front side (front surface side) of the image forming apparatus 100 refers to the side on which the door 31 as an opening/closing member is provided. The rear side of the image forming apparatus 100 is the side opposite to the front side. "frontward" means a "direction toward the front as viewed from the apparatus main assembly rear side of the image forming apparatus 100, and" rearward "means a direction opposite to" frontward ". "left and right sides" refer to left and right side surfaces (of the apparatus main assembly) as viewed from the front side of the image forming apparatus 100. "to the left" means "a direction toward the left side when viewed from the front side," and "to the right" means a direction opposite to "to the left". The apparatus main assembly (main assembly frame) 100A is an image forming apparatus portion other than the process cartridge.

In the apparatus main assembly 100A, four (first to fourth) process cartridges PY, PM, PC, and PK are horizontally arranged in the listed order from the rear to the front (in-line or cascade arrangement). These four process cartridges have the same constitution except that they contain toners different in color. Each process cartridge in the present embodiment includes a drum-type electrophotographic photosensitive member 1 (hereinafter simply referred to as "photosensitive drum") as a first image bearing member, a developing device 3, and a cleaning device 4, which are integrally fitted in a cartridge frame 5. The charging device 2 is a contact type charging roller. The developing device 3 includes a developing roller 3a as a developer bearing member for bearing a developer to develop a latent image formed on the photosensitive drum 1, and a developer container including an accommodating portion for accommodating the developer (toner). The removing device 4 is of the scraper type.

The developing device 3 of the first process cartridge PY stores yellow (Y) toner. A yellow (Y) toner (developer) image is formed on the peripheral surface of the photosensitive drum 1 in the process cartridge PY. The developing device 3 of the second process cartridge PM stores magenta (M) toner. A magenta (M) toner image is formed on the outer peripheral surface of the photosensitive drum 1 in the process cartridge PM. The developing device 3 of the third process cartridge PC stores cyan (C) toner. A cyan (C) toner image is formed on the peripheral surface of the photosensitive drum 1 in the process cartridge PC. The developing device 3 of the fourth process cartridge PK stores black (K) toner. A black (K) toner image is formed on the peripheral surface of the photosensitive drum 1 in the process cartridge PK.

The laser scanning unit 11 is disposed in an area above the process cartridges PY, PM, PC, and PK. The laser scanning unit 11 outputs a laser beam L modulated corresponding to image (picture) information of each color inputted to the control circuit section 200 from an external host device. The output laser light L is transmitted through an exposure window 6 provided at the upper surface of the cartridge frame 5 and into each cartridge. Thus, laser scanning exposure is performed on the surface of the photosensitive drum 1.

The apparatus main assembly 100A includes an intermediate transfer belt unit 12. The intermediate transfer belt unit 12 is disposed below the process cartridges P (PY, PM, PC, PK). The intermediate transfer belt unit 12 includes an endless belt 13. The belt 13 is a transfer member (second image bearing member) contactable with the photosensitive drum 1 of each process cartridge. The belt 13 is made of a dielectric material and has flexibility. Inside the belt 13 are a drive roller 14, a turn roller 15 and a tension roller 16, around which the belt 13 is drawn and circulated, the drive roller 14, the turn roller 15 and the tension roller 16. The driving roller 14 and the tension roller 16 are disposed on the rear side of the apparatus main assembly 100A, and the steering roller 15 is disposed on the front side of the apparatus main assembly 100A. The lower surface of the photosensitive drum 1 of each process cartridge P is in contact with the upper surface of the belt 13. Four primary transfer rollers 17 are disposed inside the belt 13. Each transfer roller 17 is disposed opposite to the photosensitive drum 1 in the corresponding process cartridge by the endless belt 3. The drive roller 14 is disposed opposite to the secondary transfer roller 22 through the belt 13.

A sheet feeding unit 18 including a sheet feeding cassette 19, a feeding roller 20, and a separation pad 21 is arranged below the intermediate transfer belt unit 12. The sheet feeding cassette 19 is detachably mounted in the apparatus main assembly 100A from the front side (front end loading).

A fixing device 23 and a sheet discharging roller pair 24 are arranged at an upper portion on the rear side of the apparatus main assembly 100A. Further, a sheet discharging portion 25 is provided at an upper surface of the apparatus main assembly 100A. The fixing device 23 includes a fixing film assembly 23a and a pressure roller 23 b. The sheet discharging roller pair 24 includes sheet discharging rollers 24a and 24 b.

Each process cartridge P located at a transfer contact position (latent image forming position) in the apparatus main assembly 100A is fixed at a predetermined positioning portion by the pressing of a pressing member described later. The transfer contact position (latent image forming position) refers to a position where the photosensitive drum 1 and the belt 13 contact each other and a latent image can be formed on the photosensitive drum 1. At this transfer contact position, the driving force input portion of the process cartridge P is engaged with the driving force output portion of the apparatus main assembly 100A. The electric power supply system of the apparatus main assembly 100A is electrically connected to the electric contacts of the process cartridges P.

The operation of the image forming apparatus for forming a full color image is described below. The photosensitive drum 1 of each of the first to fourth process cartridges P (PY, PM, PC, and PK) is rotationally driven at a predetermined speed in a counterclockwise direction indicated by an arrow. In addition, the belt 13 is rotationally driven at a speed corresponding to the speed of the photosensitive drum 1 in a clockwise direction indicated by an arrow (a (normal) rotational direction of the photosensitive drum 1). Also, the scanning unit 11 is driven. In synchronization with the driving of the scanner unit 11, the charging roller 2 in each process cartridge P uniformly charges the surface of the photosensitive drum 1 to a predetermined polarity and potential at a predetermined timing. The scanning unit 11 scans (exposes) the surface of each photosensitive drum 1 with a laser beam L modulated corresponding to picture (image) signals of the corresponding color. Accordingly, electrostatic latent images corresponding to image signals of the respective colors are formed on the surface of the photosensitive drum 1. The electrostatic latent image is developed into a developer image (toner image) by the developing device 3.

Through the above electrophotographic image forming process, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 1 of the first process cartridge PY. The yellow toner image is primarily transferred onto the belt 13.

A magenta developer image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 1 of the second process cartridge PM, and this magenta toner image is transferred (primary transfer) onto the belt 13 so that it is superimposed on the yellow toner image that has been transferred onto the belt 13.

A cyan developer image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 1 of the third process cartridge PC, and this cyan developer image is primarily transferred onto the belt 13 so that it is superimposed on the yellow and magenta toner images that have been transferred onto the belt 13.

A black developer image corresponding to the black component of the full-color image is formed on the photosensitive drum 1 of the fourth process cartridge PK, and this black developer image is primarily transferred onto the belt 13 so that it is superimposed on the yellow, magenta and cyan toner images that have been transferred onto the belt 13.

Accordingly, an unfixed full-color toner image is synthetically formed on the belt 13 by the yellow, magenta, cyan, and black toner images.

After the primary transfer, the transfer residual toner remaining on the surface of the photosensitive drum 1 in each process cartridge is removed by the cleaning device 4.

Meanwhile, the sheet feeding roller 20 is driven at a predetermined timing. The sheets P stacked on the sheet feeding cassette 19 are separated and fed one by cooperation of the sheet feeding roller 20 and the separation pad 21. Thus, the sheet P is introduced into the nip (secondary transfer nip) between the secondary transfer roller 22 and the belt 13. During nip conveyance of the sheet P, the overlapped four color toner images are simultaneously transferred onto the sheet P.

The sheet P is separated from the surface of the belt 13 and introduced into the fixing device 23, and is heated and pressed in a fixing nip portion of the fixing device 23. Accordingly, color mixing of the respective color toner images and fixation of the respective color toner images on the sheet P are performed. After that, the sheet P is removed from the fixing device 23, and then discharged as a full color image forming product onto a sheet discharge portion 25 by a discharge roller pair 24.

After the sheet P is separated from the belt 13, the secondary transfer residual toner remaining on the surface of the belt 13 is removed by a cleaning device 4 (not shown).

(Process Cartridge Replacing method)

The process cartridge replacement method is described below with reference to fig. 1 to 10, 17, 19, 22 and 23.

When each of the first to fourth process cartridges PY, PM, PC, and PK performs an image forming operation, the developer (toner) stored in the developing device 3 of each process cartridge is consumed. Then, when the developer is consumed to such an extent that an image of a quality satisfactory to the user who purchased the process cartridge cannot be formed, the commercial value of the process cartridge is lost.

For this reason, for example, the image forming apparatus is provided with a device (not shown) for detecting the amount of developer remaining in each process cartridge. The detected amount of the developer in each process cartridge is compared with a threshold value set in advance for issuing a process cartridge life warning or alarm by the control circuit portion 200. When the detected amount of the residual developer in the process cartridge is less than a predetermined critical value, an early warning or warning of the life of the process cartridge is displayed on a display portion (not shown). Therefore, the image forming apparatus prompts the user to prepare a replacement process cartridge, or to replace a process cartridge, in order to maintain the output image quality.

In this embodiment, the replacement of the process cartridge P is performed by placing the process cartridge on the pull-out type tray 35 and replacing it in a front-side pick-and-place manner. Therefore, usability is improved.

Here, on the front side of the apparatus main assembly 100A, an opening 30 is provided through which the tray 35 (process cartridge P) passes when the process cartridge P is pushed into the apparatus main assembly 100A or pulled out from the apparatus main assembly 100A.

In addition, on the front side of the apparatus main assembly 100A, a swing door 31 is provided. The door 31 is an opening/closing member that is positionable in a closed position to close the opening 30 and an open position to open the opening 30.

In this embodiment, horizontal (lateral) shafts 32(32L and 32R) as hinges are provided at the lower left and lower right portions of the door 31.

The door 31 is rotatably movable relative to the apparatus main assembly 100A about a horizontal shaft 32. That is, the door 31 is rotated about the horizontal shaft 32 so that it can be moved to a closed position (substantially vertical position) to cover (close) the opening 30 as shown in fig. 1 and 2, and so that it can be rotated forward about the hinge shaft 32 to an open position (substantially horizontal position) to expose (open) the opening 30 as shown in fig. 3 and 4. A manual operation portion (finger placing portion) 31a for opening/closing the door 31 is provided on the door 31.

A pair of tray holding members 34(34L and 34R) are provided to the inside of the left and right frames SOL and SOR of the main frame of the apparatus main assembly 100A, respectively. These retaining members 34 are opposed to each other. The longitudinal (length) direction of each holding member 34 coincides with the front-rear direction of the apparatus main assembly 100A. A cartridge tray (frame member) 35 is disposed between the holding members 34. This tray 35 is held by a holding member 34 so that the tray 35 can horizontally slide in the front-rear direction of the apparatus main assembly 100A. The tray 35 supports the process cartridges P, that is, the tray is provided with mounting portions for detachably mounting the plurality of process cartridges P (PY, PM, PC, and PK), respectively.

In association with the opening of the door 31, the holding members 34(34L and 34R) are moved by a predetermined distance toward the front and upward of the apparatus main assembly 100A. That is, the holding member 34 moves from the first position to the second position. Here, the first position is a position of the holding member 34 for moving the tray 35 to a transfer contact position described later (fig. 2), and the second position is a position of the holding member for moving the tray 35 between a push-in position and a pull-out position (fig. 4 and 6). The pushing-in position is a position at which the tray 35 is pushed into the apparatus main assembly 100A (fig. 4). The pulled-out position is a position at which the tray 35 is pulled out of the apparatus main assembly 100A and the process cartridge P is detachably mountable to the above-described mounting portion (fig. 6). The moving direction of the tray 35 is perpendicular to the axial direction of the photosensitive drum 1 of each process cartridge P (longitudinal direction of the process cartridge P). The holding member 34 is moved from the first position to the second position, and therefore, the front portion of the holding member 34 projects toward the front by a predetermined distance (fig. 3 and 4). The mechanism associated between the door 31 and the holding member 34 will be described below.

In association with the movement of the holding member 34 from the first position to the second position, the drive output portion on the apparatus main assembly side is disengaged (driven portion is disengaged) from the corresponding drive input portion of each process cartridge P. In addition, the pressure applied to each process cartridge P by the pressing member to position and fix the process cartridge is removed (pressure removal). In addition, the electrical conduction from the electrical power supply system on the apparatus main assembly side to the electrical contact of each process cartridge is stopped (electrically disconnected). Further, the positioning and fixing of the tray 35 are released.

As described above, when the holding member 34 is moved from the first position to the second position, the tray 35 and each process cartridge P are also moved upward together with the holding member 34 (fig. 4). That is, the tray 35 is moved from a transfer contact position (fig. 2) where the photosensitive drum 1 and the belt 13 contact each other to a transfer separation position (push-in position) where the photosensitive drum 1 and the belt 13 are separated from each other (fig. 4).

Next, all the four process cartridges P held by the tray 35 pass through the opening 30 and are pulled out of the apparatus main assembly 100A (fig. 5 and 6). That is, the tray 35 is moved from the push-in position (fig. 4) to the pull-out position (fig. 6). Therefore, the upper (top) surfaces of all the process cartridges P are exposed.

When the tray 35 is pulled out by a predetermined distance set in advance enough to expose all the process cartridges, the tray is prevented from being pulled out further by a stopper portion not shown. The tray 35 is held in the horizontal pulled-out position by the holding member 34.

The tray 35 supports the respective process cartridges P so that the process cartridges can be detachably moved directly from above. As shown by the two-dot chain line in fig. 6, the used-up process cartridge P to be replaced is lifted up and taken out from above the tray 35. Subsequently, a new process cartridge P is mounted on the mounting portion of the tray 35, and the tray 35 is moved from the pulled-out position to the pushed-in position. After that, the door 31 is closed. In association with the closing of the door 31, the holding member 34 is moved from the second position to the first position, so that the tray 35 is moved from the push-in position to the transfer contact position. In association with the movement of these holding members 34, each process cartridge P is pressed by the pressing member to be fixed to a predetermined positioning portion. Thus, the lower surface of the photosensitive drum 1 of each process cartridge P is brought into contact with a predetermined position of the belt 13. Further, a drive output portion of the apparatus main assembly 100A is connected to a drive input portion of the process cartridge P. In addition, the electric power supply system of the apparatus main assembly 100A is electrically connected to the electric contacts of the process cartridges P.

In the case where the process cartridge has an openable drum cover (not shown) for protecting the lower surface of the photosensitive drum 1, the process cartridge may be configured such that the drum cover is manually closed after the process cartridge is taken out from the tray 35 and manually opened before the process cartridge is placed on the tray 35. The process cartridge may also be configured such that the drum cover is automatically closed during the process cartridge is lifted up from the tray 35 and is automatically closed during the process cartridge is mounted onto the tray 35 from above.

In summary, the tray 35 is positionable at a pull-out position where the process cartridge P is detachably mountable to the tray 35 outside the apparatus main assembly 100A, a push-in position where the process cartridge P is pushed into the inside of the apparatus main assembly 100A, and a transfer contact position where the photosensitive drum 1 is in contact with the belt 13.

In addition, the left and right holding members 34(34L and 34R) are holding members for supporting the tray 35. The holding member 34 is positionable at a first position where the tray 35 is positioned at the transfer contact position and a second position where the tray 35 is moved between the pulled-out position and the pushed-in position.

(processing box)

Fig. 7 and 8 are external perspective views of each process cartridge P viewed from the side where the process cartridge P is driven and from the side where the process cartridge P is not driven, respectively.

In this embodiment, the leftward or rightward direction of the process cartridge P is a direction parallel to the axis of the photosensitive drum 1. Each process cartridge is an elongated rectangular box-like member, the longitudinal (length) direction of which coincides with the above-described leftward or rightward direction. The photosensitive drum 1 is rotatably supported by a pair of bearing portions 51 and 52 disposed between left and right side surface portions of the cartridge frame 5. The right bearing portion 51 is provided with a joint engaging portion 53 as a photosensitive drum drive input portion. In addition, the right side surface portion of the frame 5 is provided with a joint engaging portion 54 as a developing drive input portion for driving the developing roller 3 a. The left side surface portion of the frame 5 is provided with an electric contact 55 of the process cartridge. At both left and right side surface portions of the frame 5, a protruding portion 56 of a top plate portion of the frame 5 is provided, which protrudes in the left-right direction. At the upper surface of the frame 5, an exposure window extending in the left-right direction as the longitudinal direction is provided. With respect to each process cartridge P, the right side on which the joint engaging portions 53 and 54 are provided is a driving side, and the left side opposite to the right side is a non-driving side.

(tray)

Fig. 9 is an external perspective view of the tray 35. The tray 35 has a rectangular main frame divided into four subspaces having substantially the same size by three partition plates 35f extending in the left-right direction. Therefore, the first to fourth elongated subspaces 35(1) -35(4) are formed from the rear frame 35c side toward the front frame 35 b. These subspaces 35(1) -35(4) are portions for holding the first to fourth process cartridges PY, PM, PC, and PK, respectively. For the right frame 35e for the subspaces 35(1) - (35 (4)), the four holes 35g allow the developing drive joint 35g to move into or out of the corresponding subspaces, respectively.

In addition, the tray 35 is provided with intermediate electrical contacts 72a-72d for electrical connection with the electrical contacts 55 (fig. 8) of the corresponding process cartridges P, respectively. These intermediate electrical contacts 72a-72d can be electrically connected to main assembly-side electrical contacts 75a-75d (fig. 21 and 22) provided on the left frame 80L of the apparatus main frame 100A. These electrical contacts will be described later.

Each process cartridge P is to be inserted into the corresponding subspace of the tray 35 from above, and the bottom surfaces of the left and right projections 56 are engaged by the top surfaces of the left and right frames 35d and 35e of the tray 35. Thus, each cartridge is supported by the tray 35. That is, the tray 35 supports each process cartridge P so that the process cartridge P can be taken out from the tray 35 directly from above. The tray 35 generally supports each process cartridge P. With this structure, each process cartridge P can be easily replaced. The left and right frames 35d and 35e of the tray 35 are engaged with guide grooves 34a provided at the inner surfaces of the left and right holding members 34L and 34R, respectively, and extending in the front-rear direction of the tray 35. Thus, the tray 35 is supported by the left and right holding members 34L and 34R, and is slidable relative to the holding member 34 along the guide groove 34a in the front-rear direction (horizontal direction).

(related mechanism between door 31 and tray holding member 34 and first control member)

The mechanism and first control member associated between the door 31 and the tray holding member 34 will be described below with reference to fig. 10-15, 17, 18, 21 and 23.

Fig. 10 is a perspective view of a relevant mechanism portion between the door 31 and the holding member 34. The left and right portions 32(32L and 32R) of the door 31 are arranged horizontally with respect to the left and right direction of the apparatus main assembly 100A. These hinge portions 32 are rotatably supported by bearing members (not shown) provided on the left and right sides of the apparatus main assembly 100A, respectively. These support members may also be left and right frames 80L and 80R (fig. 23).

In addition, connecting arms 37(37L and 37R) are provided at the left and right end portions of the door 31. In this embodiment, the door 31 and the connecting arm 37 are separate components. These connecting arms 37 associate the door 31 with the retaining member 34. The hinge portions 120(120L and 120R) provided to the connecting arm 37 are arranged horizontally with respect to the left-right direction of the apparatus main assembly 100A. These hinge portions 120 are supported rotatably by bearing members (not shown) provided on the left and right portions of the apparatus main assembly 100, respectively. These support members may also be left and right frames 80L and 80R. The arms 37L and 37R are each provided with a horizontal shaft 37a and 37b, respectively. The horizontal shaft 37a of the left link arm 37L is engaged in a vertically elongated hole 34A provided on the front bottom portion of the left holding member 34L. In addition, the horizontal shaft 37B of the left link arm 37L is engaged in the groove 31B provided on the left side surface portion of the door 31. The horizontal shaft 37a of the right connecting arm 37R is engaged in a vertically elongated hole 34A provided on the front bottom portion of the right holding member 34R. In addition, the horizontal shaft 37B of the right link arm 37R is engaged in the groove 31B provided on the right side surface portion of the door 31.

That is, the door 31 and the holding member 34 are connected to each other by the connecting arm 37. Therefore, in association with the opening/closing of the door 31, the link arm 37 is rotationally moved. Therefore, a moving force in the front-rear direction acts on the left and right holding members 34.

The hinge portion 120 of the connecting arm 37 may be arranged coaxially with the hinge portion of the door 31. In addition, in the case where the connecting arm 37 is not provided, the door 31 and the holding member may be directly connected to each other.

As shown in fig. 11(a) to 11(c) and fig. 12, the left and right holding members 34 are each provided with two pins 34c arranged at intervals with respect to the front-rear direction. These pins 34c are engaged in guide holes 36 provided in the left and right frames 80(80L and 80R) of the apparatus main assembly 100A. With each pin 34c engaged in the corresponding guide hole 36, the holding members 34 are supported by the left and right frames 80, respectively.

Fig. 11(a) to 11(c) show the two pins 34c of the left holding member 34L and the guide hole 36 of the left frame 80L, respectively, but do not show the right holding member 34R. However, the right holding member 34R is identical to the left holding member 34L except that the pin 34c of the right holding member 34R and the corresponding guide hole 36 of the left frame 80L are symmetrically positioned with respect to the pin of the left holding member 34L and the corresponding guide hole 36.

Therefore, the left and right holding members 34 are movable relative to the left and right frames 80 within the guide range defined by the guide holes 36.

Fig. 12 is an enlarged view of one of the guide holes 36. Each guide hole 36 includes first, second and third guide portions 36a, 36b and 36 c. The first guide portion 36a is a horizontal portion parallel to the front-rear direction of the apparatus main assembly 100A. The second guide portion 36b extends forward and obliquely upward from the front end of the first portion 36 a. The third guide portion 36c extends forward from the front end (top) of the second guide portion 36b and is a horizontal portion parallel to the front-rear direction of the apparatus main assembly 100A. The third guide portion 36c can stably hold the pin 34 c.

In association with the opening of the door 31, the pin 34c (the holding member 34) is moved by the distance a1 along the first guide portion 36a in the horizontal direction (first movement), and then, is moved obliquely upward along the second guide portion 36b (moved by the distance a2 in the horizontal direction, and moved by the distance b in the vertical direction) (second movement). Finally, the pin 34c (the holding member 34) moves by the distance a3 in the horizontal direction along the third guide portion 36c (third movement). The vertical direction is a direction in which the photosensitive drum 1 and the belt 13 contact and separate from each other.

Fig. 11(a) shows a state in which the door 31 is fully closed on the apparatus main assembly 100A. In this state, the left and right holding members 34 have been pushed into the rearmost position in the apparatus main assembly 100A through the hinge shaft 32, the connecting arm 37, the horizontal shaft 37a, and the vertically elongated hole 34 b. In addition, each pin 34c is located at the rear end of the first guide portion 36a of the guide hole 36. Therefore, the left and right holding members 34 are held at the first position. The tray 35 held by the holding member 34 is located at the transfer contact position.

Each of the process cartridges P held in the tray 35 is subjected to the pressing force applied to the left and right upper surface portions thereof by the above-described pressing member. Therefore, the lower surface portions of the bearing portions 51 on the driving side (through which the process cartridges are positioned) and the bottom side lower surface portions of the bearing portions 52 on the non-driving side (through which the process cartridges are positioned) are fixed at the positioning portions provided on the backup member (inner side plate) of the apparatus main assembly 100A. Thus, each process cartridge P is positioned relative to the apparatus main assembly 100A. In this state, the lower surface of the photosensitive drum 1 in each process cartridge P is in stable contact with the upper surface of the belt 13.

The process cartridge engaging portions 53 and 54 of each process cartridge P are placed in a state in which the photosensitive drum driving joint and the developing driving joint of the apparatus main assembly 100A are engaged in the process cartridge engaging portions 53 and 54, respectively.

Electric power can be supplied from the apparatus main assembly 100A to the electric contacts 55a to 55d of each process cartridge P through the corresponding intermediate electric contacts.

A downwardly facing U-shaped channel 110 is provided on the right side of the tray 35. The U-shaped groove 110 is engaged with a pin 111 fixed to the right frame 80R of the apparatus main assembly 100A. Thus, the right side of the tray 35 is positioned on the apparatus main assembly 100A. A downward projection 67 is provided on the left side of the tray 35 (fig. 17, 18 and 21). The lower end portion of each projecting portion 67 is engaged in a hole 69 provided in an intermediate transfer belt holding member 68 fixed to the apparatus main assembly 100A, so that the left side of the tray 35 is positioned on the apparatus main assembly 100A. The positioning device for positioning the tray 35 may be only one of the left and right devices.

Fig. 11(b) shows a state where the door 31 is partially opened. When the door 31 in the closed state as shown in fig. 11(a) is opened, in the apparatus main assembly 100A, the holding members 34L and 34R are pulled forward in association with the opening of the door 31. Therefore, since the pin 34c is guided by the first guide portion 36a of the guide hole 36, the holding member 34 moves forward by the distance a 1. Fig. 11(b) shows this state. When the left and right holding members 34L and 34R move by the distance a1 as described above, the photosensitive drum driving joint and the development driving joint of each process cartridge P disengage. In addition, the pressure applied to each process cartridge P by the pressing member to position the process cartridge is removed. At this time, the pin 111 and the projection 67 are engaged with the U-shaped groove 110 and the hole 69, respectively, thereby preventing the tray 35 from following the horizontal movement of the holding member 34.

Subsequently, in association with the opening of the door 31, the holding member 34 is pulled further forward in the apparatus main assembly 100A. Therefore, as the pin 34c is guided by the second guide portion 36b of the guide hole 36, the holding members 34L and 34R move in the obliquely upward direction. During the slanting upward movement of the holding member 34, the electrical contact 55 of each process cartridge P is electrically separated from the corresponding portion on the apparatus main assembly 100A.

Referring to fig. 13(a), the pin 111 enters the U-shaped groove 110 by a distance c. In addition, the U-shaped groove 110 is vertically moved by a distance b due to the movement of the holding member 34 in the obliquely upward direction. During the obliquely upward movement of the holding member 34, the U-shaped groove 110 (tray 35) follows only the movement of the holding member 34 in the vertical direction as long as the U-shaped groove 110 is engaged with the pin 111 (c > b). Then, in a state where the holding member 34 is moved upward by a certain degree (c ≦ b), the pin 111 is separated from the U-shaped groove 110, so that the tray 35 can be moved horizontally. By using such a structure, the tray 35 does not move horizontally in a state where the lower surface of the photosensitive drum 1 of each process cartridge P held in the tray 35 is in contact with the belt 13. Therefore, damage and memory caused by friction between the photosensitive drum 1 and the belt 13 can be prevented. A similar structure may also be used with respect to the distance that the protruding portion 67 provided on the left side of the tray 35 enters the hole 69 provided on the belt holding member 68.

Fig. 11(c) shows a state where the door 31 is fully opened. In this state, the holding member 34 has completed the tilt-up movement by the second guide portion 36b, so that the pin 34c is located in the horizontal third guide portion 36 c. That is, the holding member 34 is held at a predetermined upper position (second position) with respect to the left and right frames 80. The reason why the pin 34c is positioned in the third guide portion 36c is to stably hold the process cartridge P and the holding member 34 at positions relative to the vertical direction, and to prevent the holding member 34 from moving backward when the process cartridge is replaced by pulling the tray 35 out of the holding member 34.

In the state shown in fig. 11(c), the pin 111 has exited the U-shaped groove 110, the protruding portion 67 has exited the hole 69, and the positioning state in which the tray 35 is located at the latent image forming position (transfer contact position) is released.

However, in a state where the holding member 34 is moved from the first position to the second position, the tray 35 held by the holding member 34 is controlled not to move from the push-in position toward the pull-out position.

The above-described grooves 110 and pins 111, and the control projections 67 and holes 69 are controlled so as not to move the tray 35 in a direction perpendicular to a direction in which the photosensitive drum 1 and the belt 13 of the process cartridge P contact each other when the tray 35 is located at the transfer contact position. After the tray 35 moves with the belt 13 and the photosensitive drum 1 held by the holding member 34 in the separating direction (upward direction) in which the photosensitive drum 1 is separated from the belt 13, such control of the movement of the tray 35 by the control members 110, 111, 67, and 69 is released.

That is, in association with the opening of the door 31, the holding member 34 performs the above-described first movement, second movement, and third movement. The holding member 34 turns off the driving means during the first movement, and the tray 35 follows the movement of the holding member 34 by the vertical movement (second movement) of the holding member 34 and then the movement of the first control members 110, 111, 67, and 69.

In this state, the tray 35 is slid and moved in the front-rear direction of the holding member 34, and is positionable at a pulled-out position where the process cartridge P can be replaced and a pushed-in position where the process cartridge P is pushed into the apparatus main assembly 100A.

Fig. 15 is a perspective view showing a state where the tray 35 is pulled out to a position where the process cartridge P is replaceable. The link arms 37(37L, 37R) as the tray supporting members have tray supporting portions 121(121L, 121R). The tray supporting portion 121 supports the tray 35 at the pulled-out position.

That is, the connecting arm 37 for associating the door 31 with the holding member 34 also functions as a supporting member that supports the tray 35 when the tray 35 is located at the pulled-out position. Therefore, it is possible to prevent the surface of the photosensitive drum 1 from being damaged due to the front portion of the tray 35 being strongly bent downward by the self weight of the tray 35 and the process cartridge P, and to prevent the apparatus main assembly 100A from being tilted due to the weight unbalance caused by pulling out the tray 35.

The tray support member 121 also functions as a guide portion during movement of the tray 35 between the pulled-out position and the pushed-in position. Therefore, the tray 35 can be moved stably and smoothly.

The connecting arm 37 is rotationally moved in association with the door 31 so that the tray supporting portion 121 is located inside the apparatus main assembly 100A when the door 31 is closed and outside the apparatus main assembly 100A when the door 31 is opened. Therefore, the tray 35 can be stably held at the pulled-out position without increasing the size of the apparatus main assembly 100A, thereby improving the usability at the time of replacing each process cartridge P. In addition, the maximum rotation radius of the connecting arm 37 (tray supporting member 121) is smaller than that of the door 31, so that the rigidity of the connecting arm 37 can be increased.

The shape and number of the supporting points of the tray supporting member for supporting the tray 35 at the pulled-out position are not limited to those shown in fig. 15. In addition, the door 31 and the tray support member 121 may also be integrally provided.

By using the above-described structure, it is possible to provide an image forming apparatus having a pull-out type process cartridge which prevents damage and memory caused by friction between the belt 13 and the photosensitive drum 1 of each process cartridge P without increasing the size and cost of the apparatus main assembly 100A.

(interface portion)

The interface portions will be described below with reference to fig. 1, 2, 5-7, 14-16, and 25.

Fig. 14 to 16 are schematic views showing an interface portion near each process cartridge, which is associated with the tray holding member 34(34L and 34R) to perform the disengaging or releasing operation.

Fig. 14 is a perspective view showing a state where the door 31 is closed as shown in fig. 1 and 2 and no cartridge is located in the tray 35. Fig. 15 is a perspective view showing a state where the door 31 is opened as shown in fig. 5 and 6 and the tray 35 has been pulled out.

On the right side in the apparatus main assembly 100A, a photosensitive drum driving (force transmitting) joint 39 and a developing (roller driving force transmitting) joint 40, which are driving force output portions on the apparatus main assembly side, are connected to driving force input portions 53 and 54 (fig. 7) on the process cartridge side so as to drive the photosensitive drum 1 and the developing roller 3a in each process cartridge, respectively.

On the left and right sides in the apparatus main assembly 100A, supporting members 81L and 81R are provided (fig. 25). In addition, cartridge positioning portions 41(41Y, 41M, 41C, 41K) for receiving lower surface portions of the bearing portions 51 and 52 of each cartridge P are provided to the supporting members 81L and 81R, respectively (fig. 25).

Also on the left and right sides in the apparatus main assembly 100A, pressing (urging) members 42 serve to press (urge) the left and right side upper surfaces of the respective process cartridges P so that the bearing portions 51 and 52 can be engaged and fixed in the cartridge positioning portions 41. Each pressing member 42 is provided with a spring for generating the pressing force.

Fig. 16(a) is an enlarged view of the pressing member 42, the photosensitive drum driving joint 39, and the developing driving joint 40 in the state shown in fig. 14. Fig. 16(b) is an enlarged view of the pressing member 42, the photosensitive drum driving joint 39, and the developing driving joint 40 in the state shown in fig. 15.

Each pressing member 42 is rotatably provided on the apparatus main assembly 100A with a supporting point 44, and presses (presses) the right (or left) end upper surface of the corresponding process cartridge by a spring force of a pressing (pressing) spring 43. In the non-pressing (pressure-removed) state shown in fig. 16(b), the lever portion 45 of the pressing member 42 has been pushed upward by the pressing member lifting portion 46 provided on the holding member 34R, thereby removing the pressure applied to the process cartridge in association with the movement of the tray holding member 34R.

In addition, a release lever pin 47 is provided to a release lever 48 (means for removing the driving force transmitted to the process cartridge), and the release lever 48 is provided around the photosensitive drum driving joint 39 so as to retract the driving joint 39. In association with the movement of the holding member 34R, the release lever pin 47 moves from the position shown in fig. 16(a) to the position shown in fig. 16 (b). By the operation of the release lever 48, the photosensitive drum driving joint 39 and the development driving joint 40 are retracted to the positions shown in fig. 16 (b). That is, the photosensitive drum driving joint 39 and the developing driving joint 40 of each process cartridge are disengaged from the corresponding portions on the apparatus main assembly side.

In the state shown in fig. 15, that is, in the state where the photosensitive drum drive joint 39, the development drive joint 40, and the pressing member 42 are disengaged, the tray 35 is slidable. Therefore, the tray 34 is placed in a state in which it can be accommodated in and pulled out from the apparatus main assembly 100A while holding the process cartridge P thereon.

As described above, the left and right holding members 34 operate in association with the opening or closing operation of the door 31. In this case, in order to reduce the magnitude of the force necessary to open or close the door 31, the image forming apparatus may be configured such that the timing of pressure removal is slightly different from the disengagement timing of each drive joint.

That is, the photosensitive drum drive joint 39, the development drive joint 40, and the pressing member 42 are slightly different in disengagement timing. More specifically, the pin 47 and the pressing member raised portion 46 are different in position, so that the photosensitive drum joint 39 and the pressing member 42 are slightly different in disengagement (pressing) timing, and the four process cartridges are slightly different in disengagement (pressing) timing. Thus, the load applied to the door 31 is distributed. Therefore, it is possible to reduce the peak load and reduce the operation force during the user's operation of the door 31.

As described above, the retraction of the driving means (joints 39 and 40) and the vertical movement of the tray 35 are performed by the movement of the holding member 34, so that the respective mechanisms can be integrated to realize an apparatus main assembly compact in size.

(second control member and pressing member for tray)

The tray 35 in the present embodiment has a tray ejection prevention claw 101 as a second control member. The preventing claw 101 is a control means (locking means) for controlling the movement of the tray 35 from the push-in position. In addition, the pressing member 105 presses the tray 35 so as to push out the tray 35 from the push-in position toward the pull-out position by a predetermined distance with the holding member 34 located at the second position. By preventing the claws 101 and the urging member 105, the tray 35 is guided so as to be completely accommodated in the pushed-in position. The prevention claw 101 and the pressing member 105 will be described below with reference to fig. 11, 13, and 17 to 21.

Description will be made mainly with reference to fig. 19(a) to 19 (g). The prevention claw 101 is provided downward on the front side of the tray 35. The prevention claw 101 can slide vertically within a predetermined stroke range. In addition, the pawl 101 is prevented from being pressed downward by the spring 101 a. The spring 101a is compressively disposed between a spring receiving seat 101b provided on the tray 35 and the upper end of the prevention claw 101. A lever 26 as a manual operation portion and a fixed portion 35a as a holding portion are provided on the front side of the tray 35. In the fixed portion 35a, the lever 26 is swingably supported around the shaft portion 26 a. The lever 26 has an arm portion 26b as a release portion. The arm portion 26b is engaged with a vertically elongated hole 101c provided in the preventing claw 101. In the free state, at the upper end of the vertically elongated hole 101c of the prevention claw 101 pressed downward by the spring, a downward pressing force is applied to the arm portion 26b of the lever 26. Therefore, the lever 26 is rotationally moved in the clockwise direction about the shaft portion 26a to be placed in an upright state in the fixed portion 35 a. A recess 102a as a portion to be engaged with the lower end portion of the preventing claw 101 is provided on a fixing member 102 fixed to the apparatus main assembly 100A.

A pressing unit 106 for pressing the tray 35 is provided on the rear side of the apparatus main assembly 100A. The urging unit 106 includes an urging member 105, and when the holding member 34 is located at the second position, the urging member 105 urges the tray 35 from the push-in position toward the pull-out position (toward the front of the apparatus main assembly 100A) so that the tray 35 is pushed back by a predetermined distance. The urging member 105 is a lever for urging the tray 35 from the push-in position to the pull-out position by contacting at an upper portion thereof a portion to be urged 35h provided at a rear end of the tray 35. The urging unit 106 further includes an urging member 104 for urging the urging member 105 in the counterclockwise direction about a shaft portion 105a provided at a lower portion of the urging member 105, and an urging spring 103. The pressing member 104 is slidably provided in a predetermined stroke range in the front-rear direction of a fixing member 107 fixed to the apparatus main assembly 100A. The pressing spring 103 is arranged in compression between the pressing member 104 and the fixing member 107. The urging member 104 is urged toward the front of the apparatus main assembly 100A, so that the urging member 105 is urged in the counterclockwise direction about the shaft portion 105a by the urging of the urging member 104.

Fig. 19(a) shows a state in which the holding member 34 is located at the first position and the tray 35 is located at the transfer contact position due to the closing of the door 31. In this state, the pawl 101 is prevented from being lowered to a predetermined lowered position (control position) such that the lower end portion thereof is engaged in the recess 102 a. The urging member 105 is urged rearward by a portion to be urged 35h provided on the tray 35 to urge and move the urging member 104 rearward against the elasticity of the urging spring 103 to be urged in the clockwise direction about the shaft portion 105 a. The compression reaction force of the pressing spring 103 acts on the portion to be pressed 35h through the pressing member 104 and the pressing member 105.

Fig. 19(b) shows a state where the holding member 34 is located at the second position and the tray 35 is located at the pushed-in position by opening the door 31 from the state shown in fig. 19 (a). In this state, the tray moves upward by a predetermined distance, but the prevention claw 101 is still engaged with the concave portion 102a at its lower end portion. That is, the tray 35 is controlled to prevent the tray 35 from being moved from the pushed-in position toward the pulled-out position by the urging force of the urging member 105 by preventing the engagement of the claws 101 with the recesses 102 a.

Then, the fixed portion 35a provided on the front side of the tray 35 and exposed from the opening 30 and the lever 26 provided in the fixed portion 35a are held. The lever 26 and the fixed portion 35a are disposed downstream of the mounting portion of the tray 35 with respect to the pull-out direction of the tray 35. In addition, the fixed portion 35a is provided at a position closer to the pulled-out position than the lever 26. In addition, the lever 26 and the fixed portion 35a are exposed toward the upper portion of the tray 35 and project upward and forward relative to the main body of the tray 35. The lever 26 is a movable portion movable relative to the main body of the tray 35, and is fixed to the main body of the tray 35 by a fixed portion 35 a. As shown in fig. 19(c), by the above-described holding action, the lever 26 is rotationally moved in the counterclockwise direction (unlocking direction) about the shaft portion 26 a. By the rotational movement of the lever 26, the arm 26b as the release portion is moved upward in a state of being engaged with the vertically elongated hole 101 c. Therefore, the claw 101 is prevented from moving upward against the downward urging force of the spring 101 a. Therefore, the lower end portions of the claws 101 are prevented from being separated from the recessed portions to release the control of the movement of the tray 35. That is, the claw 101 is prevented from being retracted from the control position for controlling the tray 35 so as to move toward the pulled-out position, i.e., from the control position toward the pulled-out position. Then, the tray 35 is moved from the pushed-in position to a predetermined position by the urging force of the urging member 105 (fig. 19 (d)). The predetermined position is a position where only the process cartridges PK located on the foremost side of the plurality of process cartridges P are exposed (fig. 31). In addition, the direction in which the lever 26 is moved by manual operation substantially coincides with the direction in which the tray is moved from the push-in position toward the pull-out position. Therefore, the user can easily pull out the tray 35. Then, as shown in fig. 19(e), the pushed-out tray 35 slides forward with respect to the holding member 34. Therefore, as shown in fig. 5 and 6, the tray 35 is sufficiently pulled out from the opening 30 to a pulled-out position outside the apparatus main assembly 100A.

As shown in fig. 5 and 6, the tray 35 is pulled out to a pull-out position for replacing the process cartridge to be replaced, and then, the tray 35 is sufficiently pushed into the apparatus main assembly 100A to reach a push-in position, thereby restoring the tray 35 to the state of fig. 3 and 4.

In this case, as shown in fig. 19(f), in a case where the tray 35 is positioned at a predetermined position before the push-in position, a portion to be pressed 35h provided at the rear end of the tray 35 is in contact with the upper end portion of the pressing member 105. In addition, when the tray 35 is pushed in against the pressing force of the pressing member 105, the inclined cam portion 101d provided on the lower end portion of the prevention claw 101 comes into contact with the inclined cam portion 102b provided on the fixed member 102. When the tray 35 is further pushed in against the urging force of the urging member 105, the claw 101 is prevented from moving upward against the urging force of the spring 101a by the cam action of the inclined cam portions 101d and 102 b. Therefore, as shown in fig. 19(g), the claw 101 is prevented from moving onto the upper surface of the fixed member 102. Thus, the pawl 101 is prevented from moving from the control position to the retracted position. Thereafter, the tray 35 is continuously pushed in against the urging force of the urging member 105. Thus, the prevention claw 101 is moved to the position of the recess 102a, so that the lower end portion of the prevention claw 101 is engaged in the recess 102a by the downward movement caused by the spring 101 a. That is, the pawl 101 is prevented from moving from the retracted position to the control position. Thus, as shown in fig. 19(b), the tray 35 is locked in the apparatus main assembly 100A. That is, by sufficiently pushing the tray 35 to the push-in position, the claws 101 are prevented from being engaged in the recesses 102 a. Thus, the movement of the tray 35 is controlled at the push-in position.

Then, by closing the door 31, the holding member 34 is moved from the second position to the first position. Therefore, as shown in fig. 19(a), the tray 35 is moved to the transfer contact position (latent image forming position) to place the image forming apparatus 100 in a state in which the apparatus can perform an image forming operation.

Fig. 17 is a perspective view showing a state where the tray 35 is not pushed into the pushed-in position in a case where the holding member 34 is pushed up by the opening operation of the door 31. Fig. 18 is a perspective view showing a state where the tray 35 is completely pushed in to the pushed-in position.

In a state where the tray 35 is not completely pushed in as shown in fig. 17, the claw 101 and the recess 102a are prevented from not engaging with each other. In this case, the tray 35 is pushed back by the pressing member 105 toward the pulled-out position by a predetermined distance (fig. 19(f) and 20 (a)). That is, in a case where the tray 35 is located at a predetermined position (excluding the push-in position) between the pull-out position and the push-in position, the tray 35 is returned toward the pull-out position. The predetermined position is a position close to the pushing-in position where the tray 35 can be brought into contact with the pressing member 105 and only the process cartridges PK of the plurality of process cartridges P are exposed. Then, the tray 35 is pressed by the pressing member 105, so that the tray 35 is returned toward the pulled-out position. The position of the returned tray 35 is also a position where only the process cartridges PK of the plurality of process cartridges P are exposed (fig. 31). In this state, the door 31 cannot be closed, so that the holding member 34 cannot be moved from the second position to the first position. That is, as shown in fig. 20(a), in association with the closing operation of the door 31, when the link arms 37(37L, 37R) as the interference members are rotationally moved, the interference portions 122(122L, 122R) provided on the link arms 37(37L, 37R) are brought into contact with the lower surface of the tray 35 in the returned state. For this reason, the holding member 34 cannot be pushed down toward the rear lower side of the apparatus main assembly 100A (i.e., cannot be moved from the second position to the first position) by closing the door 31. In other words, in a state where the tray 35 is located at a position other than the push-in position, the opening 30 cannot be closed.

On the other hand, in the state shown in fig. 18 in which the tray 35 is pushed into the pushed-in position, when the connecting arm 37 is rotationally moved in association with the closing operation of the door 31, the interference portion 122 does not interfere with the tray 35 (fig. 20 (b)). For this reason, the holding member 34 and the tray 35 can be pushed down (i.e., can be moved from the second position to the first position) by closing the door 31.

As described above, the tray 35 is pressed from the rear by the pressing unit 106 (pressing member 105). For this reason, in a case where the user does not push the tray 35 sufficiently into the push-in position, the tray 35 protrudes from the apparatus main assembly 100A by a predetermined distance depending on the stroke amount of the spring 103 of the pressing unit 106 (fig. 19 (f)). At this time, the tray 35 is in the state shown in fig. 17 and 20 (b). Therefore, in the case where the user erroneously closes the door 31 without pushing the tray 35 into the pushed-in position, the interference portion 122 protruding from the connecting arm 37 reliably interferes with the tray, so that the user can be prompted to correct the erroneous operation.

On the other hand, in the state shown in fig. 18 and 20(b) in which the tray 35 is pushed into the pushed-in position, the claws 101 are prevented from being engaged in the recesses 102 a. Thus, as shown in fig. 19(b), the tray 35 is positioned relative to the apparatus main assembly 100A. Therefore, in this state, when the door 31 is closed, it is possible to reliably engage not only the U-shaped groove 110 (fig. 11(a) -11 (c)) of the tray 35 with the pin 111, but also the protruding portion 67 with the positioning hole 69.

As described above, with the tray 35 in the pushed-in position, the holding member 34 can be moved from the second position to the first position (i.e., the tray 35 can be moved from the pushed-in position to the transfer contact position). In addition, in a case where the tray 35 is not pushed into the pushed-in position, the tray 35 is pushed back toward the pulled-out position by a predetermined distance by the pressing member 105. Therefore, the tray 35 interferes with the door 31, so that the door 31 cannot be closed. In addition, the holding member (holding means) 34 cannot move from the second position to the first position.

The number and shape of the prevention claws 101 and the recesses 102a are not limited to those shown in fig. 19(a) to 19 (g). In addition, the number, shape, and structure of the pressing units 106 as shown in fig. 19(a) to 19(g) may also be changed as appropriate. In addition, a release mechanism provided to the tray 35 may also be provided to the apparatus main assembly 100A.

In this embodiment, the process cartridge P can be easily replaced with a front end pick and place type. Each process cartridge P can be replaced in a state where it is mounted in the tray 35. In addition, the process cartridge P can be positioned by the members on the apparatus main assembly 100A side during its mounting to the apparatus main assembly 100A. The tray 35 is configured to substantially hold the process cartridges P and move between the drawn-out position and the pushed-in position. Therefore, without paying attention to the positioning of the tray 35 at the pulled-out position, the user can put each process cartridge P into the tray 35 from directly above the corresponding mounting position of the tray 35. Thereafter, the user pushes the tray 35 to the push-in position and closes the door 31, and therefore, the process cartridge P can be reliably positioned. Therefore, it is possible to provide an image forming apparatus which is simple in user operation and can ensure the positional accuracy of each process cartridge P.

When the tray 35 is operated in a state where the tray 35 is not completely lifted to the second position, that is, in a state where the door 31 is half-opened, there is a possibility that an image problem may occur due to friction of the photosensitive drum 1 of each process cartridge P with the belt 13. However, in this embodiment, by providing a member for controlling the movement of the door 31 in association with the tray 35 and providing a member for controlling the movement of the tray 35 by the opening/closing operation of the door 31, a state can be achieved in which the tray 35 cannot be operated until the user completely opens the door 31.

In addition, by using the structure in which the tray 35 is projected from the apparatus main assembly 100A by a predetermined distance, unless the user completely accommodates the tray 35 in the apparatus main assembly 100A, it is possible to notify the user that the door 31 cannot be closed until the user completely accommodates the tray 35 in the apparatus main assembly 100A. Therefore, the breakage of the parts of the image forming apparatus caused by the erroneous operation by the user can be avoided.

Incidentally, the above-described combination of the protruding portion 67 and the hole 69 (fig. 21(a) to 21(c)) can be used as a substitute for the prevention claw 101 shown in fig. 19(a) to 19 (g). This will be described below with reference to fig. 17, 18 and 21.

When the tray 35 is in the state shown in fig. 17, i.e., the tray has not been completely pushed back into the apparatus main assembly, the projecting portion 67 of the tray 35 is not aligned with the hole 69 provided on the belt holding member 68 (fig. 21 (a)). When an attempt is made to close the door 31 in this state, the holding member 34 is lowered together with the tray 35 by the connecting arm 37. At this time, the protruding portion 67 strikes the belt holding member 68. For this reason, the door 31 cannot be closed.

On the other hand, in the state shown in fig. 18, i.e., the state in which the tray 35 has been pushed back into the apparatus main assembly completely, the projecting portion 67 enters the hole 69 as shown in fig. 21(b) and 21 (c). Therefore, the door 31 can be closed to lower the holding member 34 and the tray 35. Therefore, the door 31 can be completely closed.

Therefore, the tray 35 can only be lowered when the tray 35 is in the pushed-in position, so that each process cartridge P is accurately positioned by the positioning member 41.

Referring to fig. 17, 18 and 21(a) to 21(c), in this embodiment, the tray 35 is provided with two protruding portions 67 having the same shape, and the tape holding member 68 is provided with two holes 69 having the same shape. However, the number and shape of the projections 67 and the holes 69 are not necessarily as shown in fig. 17, 18, and 21(a) to 21 (c). In addition, when two or more projections and holes are provided, they do not necessarily have the same shape. In addition, the manner in which each projection 67 fits into a corresponding hole 69 need not be exactly as shown in fig. 17, 18 and 21(a) to 21 (c). Also, the hole 69 need not be provided to a portion of the belt support member 68.

As shown in fig. 11(a) to 11(c), a similar effect can be achieved by a combination of a pin 111 provided on the right frame 80R and a U-shaped groove 110 provided on the tray 35. Also in this case, the number and shape of the bonding points are not necessarily as shown in fig. 11(a) to 11 (c).

(electric energy supply composition)

A method of supplying electric power from the apparatus main assembly 100A to each process cartridge P will be described below with reference to fig. 22, 23, 24(a) and 24 (b).

Fig. 21 and 22 each show a state in which the tray 35 has been completely pulled out by opening the door 31. The tray 35 is provided with plural sets of intermediate electric contact springs 72a to 72d which are arranged in a direction parallel to the horizontal direction of the apparatus main assembly 100A and are positioned at the same positional height with respect to the vertical direction. One end of each intermediate electrical contact spring 72 is electrically connected to a corresponding electrical contact 55 (fig. 8) of the process cartridge. That is, the tray 35 is provided with intermediate electrical contacts 72a and 72d, which are electrically connected to the corresponding electrical contacts 55 of the process cartridges P, respectively.

The main frame of the apparatus main assembly 100A is provided with a plurality of main assembly contact springs 75a to 75d which are electrically connected to the main assembly side electric power supplying portion 74 provided outside the left frame 80L. These main assembly electric contact springs 75a to 75d are arranged in the horizontal direction and positioned at the same positional height with respect to the vertical direction. The main assembly electric contact springs 75a to 75d project toward the tray 35 through holes provided on the left frame 80L and holes provided on the left holding member 34L.

Fig. 24(a) and 24(b) show how the intermediate electric contact spring 72 provided on the tray 35 is electrically connected to or disconnected from the main assembly electric contact spring 75 on the apparatus main assembly side. Fig. 24(a) and 24(b) show the same parts in cross section of the tray 35, the intermediate electric contact spring 72, the left tray holding member 34L, the left frame 80L, the main assembly electric contact spring 75, the main assembly electric contact spring support 76 and the electric power supplying portion 74 on the apparatus main assembly side, as viewed from the front side of the apparatus main assembly 100A.

Fig. 24(a) shows a state in which the door 31 is in the closed position, and the left tray holding member 34L and the tray 35 have been lowered to be in the transfer contact position. In this state, the main assembly electrical contact spring 75 is in electrical contact with the intermediate electrical contact spring 72.

Fig. 24(b) shows a state where the door 31 is at the open position, and the left tray holding member 34L and the tray 35 have reached positions after having been lifted from the transfer contact position. In this state, the main assembly electrical contact spring 75 and the intermediate electrical contact spring 72 are in an electrically disconnected state. In order to prevent the tray 35 from contacting a portion of the main assembly electrical contact spring 75 projecting toward the tray 35 through the left holding member 34L, the tray 35 is provided with a groove 77 extending in the front-rear direction of the apparatus main assembly 100A. Therefore, the tray 35 can be pulled out without contacting the main assembly electric contact spring 75.

That is, the apparatus main assembly 100A is provided with main assembly electrical contacts 75a to 75d arranged such that their positions do not coincide with the moving paths of the intermediate electrical contacts 72a to 72 d. The apparatus main assembly is structured such that the electrical connection between the intermediate electrical contacts and the corresponding main assembly electrical contacts can be broken by moving (raising) the tray 35 upward from the transfer contact position by the holding member 34, and can be established by moving (lowering) the tray 35 downward toward its transfer contact position by the holding member 34.

In fig. 22, 23, 24(a) and 24(b), there is shown a method of supplying electric power (electric power) to a portion of each process cartridge P to which electric power is required to be supplied, by using a combination of one main assembly electric contact spring and one intermediate electric contact spring. However, in the case where each process cartridge P is provided with a plurality of portions to be supplied with electric energy, the image forming apparatus of the present invention may also have a similar configuration. In addition, even in the case where the heights in the vertical direction of the plurality of portions to be supplied with electric power are different, the image forming apparatus can be similarly constructed by arranging the plurality of main assembly electric contact springs at different vertical position heights and providing the plurality of grooves in accordance with the heights of the main assembly electric contact springs provided on the tray 35.

In the case where the same bias is applied to the plurality of process cartridges P, an electric conductor as one intermediate electric contact electrically connectable to and disconnectable from one main assembly electric contact spring is provided in the tray 35. In addition, a plurality of intermediate electric contact springs are provided in the tray 35, which are electrically connected to the electric conductors at one end portion and electrically connectable to and disconnectable from a plurality of portions to be supplied with electric power of the plurality of process cartridges at the other end portion. With this configuration, the number of connection points between the intermediate electric contact spring and the main assembly electric contact spring can be reduced.

The tray 35 is configured to employ a configuration in which a plurality of electrical conductors for distributing electrical connections are provided in the tray 35 so as to increase the number of electrical connection points between the intermediate electrical contacts and the process cartridge electrical contacts as compared with the electrical connection points between the intermediate electrical contacts and the main assembly electrical contacts. Therefore, in the case where the same potential is used for each color, the number of parts can be reduced, resulting in cost reduction.

As described above, the intermediate electrical contact is provided to the tray 35 for mounting the process cartridges P, so that electrical connection and electrical disconnection with the apparatus main assembly 100A can be controlled by the vertical movement of the tray 35. Therefore, it is possible to provide an image forming apparatus having an easy pull-out type process cartridge replacement structure without increasing the cost and size of the apparatus main assembly.

In addition, by the tray 35 vertically moving in association with the door 31 opening and closing the opening 30, the process cartridge can be replaced in an operation easily predictable by the user.

In addition, by arranging a plurality of electrical contacts in the horizontal direction at the same vertical position height, space can be saved in the vertical direction to achieve a compact apparatus main assembly size.

(supporting Member)

Fig. 25 to 27 are perspective views each showing a main assembly frame constituting a main assembly of the image forming apparatus. A left frame 80L (not shown in these drawings) and a right frame 80R, which are first and second main frames of the apparatus main assembly, are connected and constituted by supporting members 130F, 130R, 131 and 132.

The process cartridges P (PY, PM, PC, PK) and the supporting members (81L, 81R) for holding the belt unit 12 are arranged on the supporting members 131 and 132. The supporting member 81 positions the process cartridge P and the belt unit 12. Each of the supporting members 81 is provided with four positioning portions 41(41Y, 41M, 41C, 41K) with which the bearing portions 51 and 52 of the process cartridge P are engaged to position the process cartridge P. Each positioning portion 41 has a recess having a substantially V-shaped cross section and opening upward; as described above, each process cartridge P is pressed downward by the corresponding pressing member 42, so that the process cartridge P is positioned. On the other hand, by slightly lifting the process cartridge P, the process cartridge P can be horizontally pulled out without interfering with the supporting member 81.

The belt unit 12 is arranged between the two support members 81, and the belt unit 12 is positioned by engaging the positioning projections 143 and 144 with the positioning portions 83D and 83T of the support members 81.

The support members 81(81L, 81R) are designed to have the same shape, and can be processed using a common mold. The support members 81 are relatively small in difference in size, so that they have an advantageous structure for positioning the process cartridges P and the belt unit 12. The support member 81 is bent into an L-shape and is connected to the support members 131 and 132 with screws.

The supporting members 131 and 132 position the scanning unit 11. The legs 11 a, 11b, and 11c of the scanning unit 11 are based on the support member 130, thereby determining the position of the scanning unit 11 with respect to the height direction. In addition, the positioning bosses 11d and 11e of the scanner unit 11 are engaged with the positioning holes 82c and 82d of the support member 130F. Thus, the horizontal position of the scanning unit 11 is determined. As described above, during replacement of the process cartridge P, the process cartridge P can be pulled out by slightly lifting up the process cartridge P. Therefore, it is not necessary to provide a large space for replacing the process cartridge below the scanner unit 11.

Fig. 30 is a schematic view showing an assembly of a main assembly frame constituting a main frame of the image forming apparatus main assembly. By connecting the supporting members with screws in a state where the cartridge positioning portions 41Y and 41K and the scanner unit positioning portion 82 hit the assembling tool 400, the positional accuracy of the main assembly frame can be ensured.

The support member 81 is held by the support members 131 and 132. The support member 131 has abutment portions 147, 148, and 149 on which the half-blanking process has been performed upward, and the other portions of the support member 131 are spaced from the support member 81. The support member 131 is connected with screws in a state where the three abutment portions 147, 148, and 149 are pressed against the support member 81. In addition, the support member 132 is connected with a screw in a state where the support member 132 is pressed against the support member 81.

Due to the flat surface bending or kinking caused by the dimension, the component accuracy of the metal plate member such as a cold-rolled steel sheet, which is generally used for constituting the frame of the main assembly, is lowered. In addition, it is difficult to correct the accuracy of the sheet metal member having high rigidity. The support member 81 may also be connected only to the support member 131, but sometimes desired positional accuracy of the support member 81 cannot be obtained due to the influence of the component accuracy of the support member 131.

In this embodiment, the supporting member 81 is supported by the two supporting members 131 and 132, and the contact area between them is reduced, so that the influence of the component accuracy of the supporting members 131 and 132 can be eliminated. Therefore, the main assembly frame can be assembled with high accuracy.

The supporting members 131 and 132 have a two-end supporting beam structure in which both ends of each of the supporting members 131 and 132 are connected to the left frame 80L and the right frame 80R, thereby ensuring their strength with respect to an impact load during a static load (e.g., the self weight or pressing force of the process cartridge) and physical distribution, and the like.

As shown in fig. 28 and 29, the support members 131 and 132 are disposed below the tray 35. In the case where the supporting members 81 are directly connected to the side plates, they prevent the tray 35 and the holding member 34 disposed inside the side plates from moving toward the outside of the apparatus main assembly 100A. Therefore, there is a fear of increasing the size of the apparatus main assembly 100A. However, in this embodiment, the space between the side plates can be effectively utilized. More specifically, the supporting member 130F is disposed above the tray 35, so that a large opening can be provided at the front of the apparatus main assembly 100A. Therefore, the tray 35 can be moved without increasing the size of the apparatus main assembly 100A.

(Industrial Applicability)

As described above, the image forming apparatus according to the present invention can easily replace the process cartridge by the moving operation of the tray.

While the invention has been described with reference to the structures disclosed herein, it is not intended to be limited to the details shown, since it is intended to cover various modifications or changes within the scope of the following claims.

Claims

1. An electrophotographic image forming apparatus comprising:

the main assembly of the apparatus;

a process cartridge disposed in the apparatus main assembly and including a developer accommodating portion for accommodating a developer;

a tray for supporting a process cartridge, the tray being movable between a drawn-out position in which the tray is outside the main assembly of the apparatus and a pushed-in position in which the tray is inside the main assembly of the apparatus, the tray including a mounting portion for detachably mounting the process cartridge in the drawn-out position and a lever as a manual operation portion for facilitating the drawing-out of the tray;

a spring as a pressing member for pressing the tray from the push-in position to the pull-out position;

a tray ejection prevention claw as a control member for controlling movement of the tray toward the pulled-out position when the tray is located at the pushed-in position; and

an arm portion of a manual operation portion as a release portion for releasing control by the control member by operating the manual operation portion in a state where the tray is located at the push-in position,

2. An apparatus according to claim 1, wherein said control member is movable between a control position for controlling movement of said tray toward the pulled-out position and a retracted position in which said tray is retracted from the control position, and

wherein the control member is moved from the control position to the retracted position by operating the manual operation portion in a state where the tray is located at the push-in position.

3. An apparatus according to claim 2, wherein said regulating member is provided on said tray, and a portion to be engaged with said regulating member is provided on the main assembly of the apparatus, and

wherein the control member is engaged with the portion to be engaged at a control position to control the movement of the tray in a state where the tray is located at a push-in position.

4. An apparatus according to claim 1, wherein said manual operation portion is disposed downstream of said mounting portion with respect to a pull-out direction of said tray.

5. An apparatus according to claim 1, wherein said manual operation portion is exposed at an upper portion of said tray.

6. An apparatus according to claim 1, wherein said manual operation portion protrudes from a main body of said tray.

7. An apparatus according to claim 1, wherein said manual operation portion includes a moving portion movable relative to a main body of said tray, and

wherein a direction in which the moving portion is moved by the operation of the moving portion coincides with a direction in which the tray is moved from the push-in position toward the pull-out position.

8. An apparatus according to claim 1, wherein the main assembly of the apparatus includes an opening through which the tray passes when the tray is moved from the push-in position to the pull-out position, and a door capable of closing the opening in a state where the tray is located at the push-in position.

9. An apparatus according to claim 8, wherein said process cartridge includes a developer carrying member for carrying a developer to develop the latent image formed on the electrophotographic photosensitive member.

10. An apparatus according to claim 9, wherein said process cartridge includes said electrophotographic photosensitive member.

11. An electrophotographic image forming apparatus according to claim 10, wherein the main assembly of the apparatus includes a transfer member for transferring the developer image formed on the electrophotographic photosensitive member,

wherein the tray is positioned at a transfer contact position at which the electrophotographic photosensitive member and the transfer member contact each other, and a transfer separation position at which the electrophotographic photosensitive member and the transfer member are separated from each other, as the push-in position,

wherein the tray is moved from a transfer contact position to a transfer separation position by opening of the door.

12. An apparatus according to claim 1, wherein a moving direction of said tray in which said tray moves between the push-in position and the pull-out position is perpendicular to a longitudinal direction of said process cartridge.

13. An apparatus according to claim 1, wherein a plurality of process cartridges are mountable to said mounting portion.

14. An apparatus according to claim 13, wherein said tray is moved to a position where only one of said plurality of process cartridges is exposed from the main assembly of the apparatus by being urged by said urging member.

15. An apparatus according to claim 14, wherein said only one of said plurality of process cartridges contains a black developer.

16. An apparatus according to claim 8, wherein said main assembly of the apparatus includes a tray supporting member which is rotatably movable by opening and closing of a door, and wherein said main assembly of the apparatus includes a tray supporting member which is rotatably movable by opening and closing of the door, and

wherein the tray support member supports the tray when the tray is located at the pull-out position.

17. An apparatus according to claim 16, wherein said tray supporting member guides said tray when said tray moves between the push-in position and the pull-out position.

18. An apparatus according to claim 16 or 17, wherein said tray supporting member is a member separate from said door, which is rotatably movable and has a radius of rotation smaller than that of said door.

19. An electrophotographic image forming apparatus comprising:

the main assembly of the apparatus;

a tray for supporting a process cartridge, the tray being movable between a drawn-out position in which the tray is outside the main assembly of the apparatus and a pushed-in position in which the tray is inside the main assembly of the apparatus, the tray including a mounting portion for detachably mounting the process cartridge at the drawn-out position;

an arm portion as a releasing portion for releasing control by the control member in a state where the tray is located at the push-in position, and

wherein when the tray is in an incompletely pushed-in state, i.e., a predetermined position between the pushed-in position and the pulled-out position and excluding the pushed-in position, the tray is urged toward the pulled-out position by the urging member to move toward the pulled-out position.

20. An apparatus according to claim 19, wherein said predetermined position is a position close to a push-in position at which said tray can be brought into contact with said urging member.

21. An apparatus according to claim 19, wherein said control member is movable between a control position for controlling movement of said tray toward the pulled-out position and a retracted position in which said tray is retracted from the control position, and

wherein the control member moves from the retracted position to the control position when the tray is pushed in from the pulled-out position to the pushed-in position.

22. An apparatus according to claim 21, wherein said regulating member is provided on said tray, and a portion to be engaged with said regulating member is provided on the main assembly of the apparatus, and

wherein the control member engages with the portion to be engaged at a control position to control the movement of the tray in a state where the tray is located at the push-in position.

23. An apparatus according to claim 22, wherein said control member is urged from a retracted position toward a control position,

wherein an inclined portion is provided in the apparatus main assembly,

wherein the tray is moved from the control position to the retracted position by the contact of the control member with the inclined portion during the movement of the tray from the pulled-out position to the pushed-in position, and

wherein the control member is moved from the retracted position to the control position by engagement with the portion to be engaged when the tray is located at the push-in position.

24. An apparatus according to claim 19, wherein the main assembly of the apparatus includes an opening through which the tray passes when the tray is moved from the pulled-out position to the pushed-in position, and a door capable of closing the opening in a state where the tray is located at the pushed-in position.

25. An apparatus according to claim 24, wherein said main assembly of the apparatus includes a connecting arm as an interfering member rotatably movable by opening and closing of a door, and wherein said main assembly of the apparatus includes a door, and wherein

Wherein the interference member is in contact with the tray in a state where the tray is located at a position other than the push-in position so that the door cannot close the opening.

26. An apparatus according to claim 25, wherein said interference member is located inside the main assembly of the apparatus when the door closes the opening, and is located outside the main assembly of the apparatus when the door opens the opening.

27. An apparatus according to claim 25, wherein said interference member supports said tray when said tray is in the pulled-out position.

28. An apparatus according to claim 25, wherein said interference member guides said tray when said tray moves between the push-in position and the pull-out position.

29. An apparatus according to claim 25, wherein said interference member is a member separated from said door, which is rotatably movable and has a rotation radius smaller than that of the door.

30. An apparatus according to claim 24, wherein said process cartridge includes a developer carrying member for carrying a developer to develop the latent image formed on the electrophotographic photosensitive member.

31. An apparatus according to claim 30, wherein said process cartridge includes said electrophotographic photosensitive member.

32. An apparatus according to claim 31, wherein said main assembly of the apparatus includes a transfer member for transferring a developer image formed on the electrophotographic photosensitive member,

wherein the tray is positioned at a transfer contact position at which the electrophotographic photosensitive member and the transfer member are in contact with each other, the push-in position is a position at which the electrophotographic photosensitive member and the transfer member are separated from each other, and

wherein the tray is moved from the push-in position to the transfer contact position by closing of the door.

33. An apparatus according to claim 19, wherein a moving direction of said tray in which said tray is moved between the push-in position and the pull-out position is perpendicular to a longitudinal direction of said process cartridge.

34. An apparatus according to claim 19, wherein a plurality of process cartridges are detachably mountable to said mounting portion.

35. An apparatus according to claim 34, wherein said predetermined position is a position where only one of said plurality of process cartridges is exposed.

36. An apparatus according to claim 35, wherein a position of said tray moved by being urged by said urging member is a position where only one of said plurality of process cartridges is exposed.

37. An apparatus according to claim 35 or 36, wherein said only one of said plurality of process cartridges contains a black developer.