JP2010151952A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of protecting a photoreceptor when a drawer member is removed from an apparatus body. <P>SOLUTION: A process unit 10 in which four photoreceptor drums 15 are housed, and which is slidably attached to/detached from the body casing 2 includes: a shutter 32 integrally equipped with a gear part 49; and a rack lever 37 meshed with the gear part 49. By operation to attach the process unit 10 to the body casing 2, the rack lever 37 is made to abut on an abutting plate 55 in the body casing 2 and is slid, whereby the shutter 32 is moved to a shutting position where it covers the photoreceptor drum 15 and an opening position where it exposes the photoreceptor drum 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as an electrophotographic color printer.

As an electrophotographic color printer, a tandem type color laser printer having four photosensitive drums corresponding to yellow, magenta, cyan, and black toners is known.
As such a tandem type color laser printer, for example, a drum unit including a plurality of photosensitive drums and a plurality of developing cartridges detachably attached to the respective photosensitive drums is detachably attached to the main body casing. A color laser printer has been proposed (see, for example, Patent Document 1).
JP 2007-178657 A

However, since the configuration described in Patent Document 1 does not include a member for protecting the photosensitive drum, the photosensitive drum is always exposed when the drum unit is pulled out from the main body casing.
For this reason, when the drum unit is detached, the exposed photosensitive drum may come into contact with surrounding articles and be damaged.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of protecting a photosensitive member when a drawer member is detached from the apparatus main body.

  In order to achieve the above object, an invention according to claim 1 is an image forming apparatus, which houses an apparatus main body and a plurality of photoconductors arranged in parallel at intervals, and is slidable with respect to the apparatus main body. A drawer member that is attached and detached, a shutter member that moves between a closed position that covers the photoconductor and an open position that exposes the photoconductor, and is connected to the shutter member, and the shutter member is moved to the open position or the closed position. A member to be moved; a member that is slidably provided along the parallel direction on the drawer member; and a member that acts on the member to be acted upon by sliding; and the drawer member provided inside the apparatus main body. It is characterized by comprising a contact member that contacts the action member at the time of mounting and slides the action member.

According to a second aspect of the present invention, in the first aspect of the present invention, the action member is attached in a direction opposite to a contact direction of the contact member with respect to the action member when the drawer member is mounted. It is characterized by including a first urging member for urging.
According to a third aspect of the present invention, in the first or second aspect of the present invention, the apparatus main body includes an endless belt that comes into contact with the photoconductor, and the drawing member is connected to the contact member. It is movable to a contact position where the action member abuts and a mounting position where the attachment to the apparatus main body is completed, and the contact member and the action member are in contact with each other from the contact position. The shutter member is moved to the mounting position, and the shutter member is moved to the open position while the drawer member moves from the contact position to the mounting position so as not to interfere with the endless belt. Yes.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the shutter member on the most upstream side in the mounting direction of the drawer member is an image forming member on which an image is formed. , And also serves as a guide member for guiding between the photosensitive member and the endless belt.
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the drawer member rotatably supports the photosensitive members, and the actuated member and the shutter member are It is characterized by having.

According to a sixth aspect of the present invention, in the invention according to the fifth aspect, the actuated member includes a gear that can rotate forward and backward, and the acting member includes a rack portion that meshes with the gear. And the gear is configured to move the shutter member to the open position or the closed position by rotating forward or backward.
The invention according to claim 7 is the invention according to claim 5 or 6, wherein the gear and the rack portion are provided on one side in the longitudinal direction of the photoconductor.

  The invention according to claim 8 is the invention according to claim 5, wherein the action member includes a reciprocating member that is slidable in the parallel direction, and the actuated member supports the shutter member. The reciprocating member is provided with a fitting hole including a first position and a second position, and the arm member is swingably supported at the one end by the drawer member, and has the other end. And a reciprocating member that is connected to the shutter member and is fitted to the fitting hole between the one end portion and the other end portion. The shutter member is moved to the open position by being disposed at one position, and the shutter member is moved to the closed position by being disposed at the second position.

The invention according to claim 9 is the invention according to claim 8, wherein the fitting portion is loosely fitted in the fitting hole.
Further, the invention according to claim 10 is the second urging for urging the arm member so that the shutter member is always arranged at the closed position in the invention according to claim 8 or 9. It is characterized by comprising a member and a third urging member for urging the shutter member so as to always face the photoconductor in the closed position.

An eleventh aspect of the present invention is the invention according to any one of the eighth to tenth aspects, wherein the pull-out member has the arm member when the shutter member is disposed at the closed position. It is characterized by having a holding part for holding the other end part.
The invention according to claim 12 is the invention according to any one of claims 8 to 11, wherein the arm member supports both ends of the shutter member in the longitudinal direction of the photosensitive member. It is characterized by.

  The invention according to claim 13 is the invention according to any one of claims 8 to 12, wherein the shutter member has a stopper portion at an end opposite to the end connected to the arm member. The stopper portion contacts the drawer member when the shutter member is disposed at the closed position, and makes the shutter member face the photoconductor with a gap.

According to a fourteenth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the drawer member is detachably provided with a process cartridge including the photosensitive member, and the process cartridge is An action member and the shutter member are provided.
The invention according to claim 15 is the invention according to claim 14, wherein the acting member includes a first engaging portion, and the acted member is engaged with the first engaging portion. The first engagement portion and the second engagement portion are engaged when the process cartridge is mounted on the drawer member.

  According to the first aspect of the present invention, if the shutter member is disposed at the closed position when the drawer member is detached from the apparatus main body, the drawer member is attached to the apparatus main body when the drawer member is attached to the apparatus main body. When sliding with respect to the main body, the action member provided on the drawer member comes into contact with the contact member provided inside the apparatus main body, and slides to act on the actuated member. Thereby, the shutter member can be moved to the open position.

Therefore, when the drawer member is detached from the apparatus main body, the shutter member can be moved to the open position by placing the shutter member in the closed position and attaching the drawer member to the apparatus main body.
As a result, the photoconductor can be protected when the drawer member is detached from the apparatus main body.

According to the second aspect of the present invention, the action member is slid in the direction opposite to the contact direction of the contact member with respect to the action member when the drawer member is mounted by the urging force of the first urging member. Can do.
Therefore, when the drawer member is detached from the apparatus main body and the contact between the action member and the contact member is released, the shutter member can be automatically moved to the closed position.

As a result, the photoconductor can be reliably protected when the drawer member is detached from the apparatus main body.
According to the third aspect of the present invention, the drawer member moves from the contact position to the mounting position while maintaining the contact after the contact member and the action member contact at the contact position. And attached to the main body of the apparatus.

At that time, the shutter member is moved to the open position while the drawer member moves from the contact position to the mounting position so as not to interfere with the endless belt.
Therefore, the shutter member can be arranged at the closed position until the drawer member is arranged at the contact position, and can be moved to the open position at the timing when the drawer member moves from the contact position to the mounting position.

As a result, the photosensitive member can be protected from when the drawer member is detached from the apparatus main body until just before the photosensitive member and the endless belt come into contact with each other.
Further, the shutter member is moved to the open position so as not to interfere with the endless belt.
Therefore, it is possible to prevent the endless belt from being damaged due to the interference between the shutter member and the endless belt.

According to the fourth aspect of the present invention, the shutter member on the most upstream side in the mounting direction of the drawer member also serves as a guide member for guiding the image forming member between the photosensitive member and the endless belt.
Therefore, it is not necessary to provide a separate guide member, and the number of parts can be reduced.
According to the fifth aspect of the present invention, each photoconductor is supported by the drawer member, and the drawer member includes the actuated member and the shutter member.

Therefore, each photoconductor can be protected in a configuration in which each photoconductor is supported by the drawer member.
According to the sixth aspect of the present invention, when the action member slides when the drawer member is attached or detached, the rack portion of the action member acts on the gear of the actuated member to rotate the gear forward or backward. Thereby, the shutter member can be moved to the open position or the closed position.

Therefore, with a simple configuration, the shutter member can be moved to the open position or the closed position in conjunction with the attachment / detachment of the drawer member to the apparatus main body.
According to the seventh aspect of the present invention, the gear and the rack portion are provided on one side in the longitudinal direction of the photosensitive member.
Therefore, it is not necessary to provide a gear and a rack part on the other side in the longitudinal direction of the photosensitive member, and the number of parts can be reduced.

According to the eighth aspect of the present invention, the reciprocating member is formed with the fitting hole including the first position and the second position, and the fitting portion is fitted to the arm member that is swingably supported by the drawer member. And the fitting portion is fitted in the fitting hole.
The reciprocating member slides when the drawer member is attached / detached, thereby acting on the arm member via the fitting portion to swing the arm member. When the arm member is swung so that the fitting portion is disposed at the first position, the shutter member is moved to the open position, and the arm member is swung so that the fitting portion is disposed at the second position. Then, the shutter member moves to the closed position.

Therefore, with a simple configuration, the shutter member can be moved to the open position or the closed position in conjunction with the attachment / detachment of the drawer member to the apparatus main body.
According to the ninth aspect of the present invention, since the fitting portion and the fitting hole are loosely fitted, when the fitting portion moves between the first position and the second position, It is possible to move while properly retracting to the play portion of the fitting hole.

Therefore, the arm member can be swung smoothly, and the shutter member can be smoothly moved to the open position or the closed position.
According to the tenth aspect of the invention, the arm member always swings so that the shutter member is disposed at the closed position by the urging force of the second urging member. Further, the shutter member is always directed to the photosensitive member in the closed position by the urging force of the third urging member.

Therefore, when the drawer member is detached from the apparatus main body and the contact between the action member and the contact member is released, the shutter member can be automatically moved to the closed position. In addition, the photoconductor and the shutter member can be opposed to each other in the closed position.
As a result, the photoconductor can be reliably protected when the drawer member is detached from the apparatus main body.

According to the eleventh aspect of the invention, when the shutter member is disposed at the closed position, the other end of the arm member is held by the holding portion of the drawer member.
Therefore, the swinging of the arm member can be restricted at the position where the shutter member is disposed at the closed position.
As a result, the shutter member can be reliably disposed at the closed position.

According to the invention of claim 12, the arm member supports both ends of the shutter member in the longitudinal direction of the photosensitive member.
Therefore, the shutter member can be reliably supported in the longitudinal direction of the photoconductor.
According to a thirteenth aspect of the present invention, the shutter member is exposed to light when the stopper portion provided at the end opposite to the end connected to the arm member abuts the drawer member at the closed position. It is opposed to the body with a gap.

Therefore, it is possible to prevent the shutter member from interfering with the photosensitive member when the shutter member is disposed at the closed position.
According to the fourteenth aspect of the present invention, the drawer member includes a process cartridge including a photosensitive member in a detachable manner, and the process cartridge includes an actuated member and a shutter member.

Therefore, the photoconductor can be protected in the configuration in which the photoconductor is provided in the process cartridge.
According to the fifteenth aspect of the present invention, when the process cartridge is mounted on the drawer member, the first engaging portion provided in the operating member and the second engaging portion provided in the operated member are engaged. Match.

As a result, when the process cartridge is mounted on the drawer member and the drawer member is mounted on the apparatus main body, the action member acts on the second engagement portion of the member to be acted via the first engagement portion.
Therefore, when the process cartridge is detached from the drawer member and when the drawer member is detached from the apparatus main body, the shutter member is disposed at the closed position, and the shutter is operated by attaching the drawer member to the apparatus main body. The member can be moved to the open position.

  As a result, the photosensitive member can be protected when the process cartridge is detached from the drawer member and when the drawer member is detached from the apparatus main body.

1. 1 is a side sectional view showing a first embodiment of a color laser printer as an example of an image forming apparatus of the present invention.
The color laser printer 1 is a horizontal tandem type color laser printer, and feeds paper P as an example of an image forming member into a main body casing 2 as an example of an apparatus main body. A unit 3 and an image forming unit 4 for forming an image on the fed paper P are provided.
(1) Main Body Casing The main body casing 2 is formed in a box shape having a substantially rectangular shape in side view for accommodating the image forming unit 4, and a front cover 5 for attaching / detaching a process unit 10 described later on one side wall thereof. Is provided.

In the following description, the side where the front cover 5 is provided (left side in FIG. 1) is the front side, and the opposite side (right side in FIG. 1) is the rear side. In addition, when the color laser printer 1 is viewed from the front side, the left and right reference is used. That is, the front side in FIG. 1 is the right side and the back side is the left side.
(2) Paper Feed Unit The paper feed unit 3 includes a paper feed tray 6 that accommodates the paper P. The paper feed tray 6 is detachably attached to the bottom of the main casing 2. Above the front end of the paper feed tray 6, a paper feed roller 7 and a paper feed path 8 comprising a U-turn path are arranged.

The paper P stored in the paper feed tray 6 is fed one by one toward the paper feed path 8 by the rotation of the paper feed roller 7. Thereafter, the paper P is conveyed from the paper feed path 8 toward the image forming unit 4 (between a photosensitive drum 15 (described later) and a conveyor belt 20 (described later)).
(3) Image Forming Unit The image forming unit 4 includes a scanner unit 9, a process unit 10 as an example of a drawer member, a transfer unit 11, and a fixing unit 12.
(3-1) Scanner Unit The scanner unit 9 is disposed on the upper part of the main body casing 2. As indicated by chain lines, the scanner unit 9 emits laser beams based on image data toward four photosensitive drums 15 (described later) to expose the photosensitive drums 15 (described later).
(3-2) Process Unit (3-2-1) Configuration of Process Unit The process unit 10 is disposed below the scanner unit 9 and above the paper feed unit 3, and includes one process frame 13 and And four developing units 14 corresponding to the respective colors.

The process frame 13 is slidable along the front-rear direction with respect to the main body casing 2 and is detachably provided. The process frame 13 accommodates a photosensitive drum 15 and a charging roller 16 as an example of a photosensitive member.
Four photosensitive drums 15 are arranged in parallel along the left-right direction at intervals in the front-rear direction, corresponding to each color of yellow, magenta, cyan, and black.

The charging roller 16 is disposed adjacent to the photosensitive drum 15 on the rear side of the photosensitive drum 15.
The developing unit 14 is disposed on the upper side of the photosensitive drum 15 and includes a developing roller 17.
The developing roller 17 is rotatably supported by the developing unit 14 so as to be exposed from the lower end of the developing unit 14 and is disposed so as to contact the photosensitive drum 15 from above.

Although not shown, the developing unit 14 includes a supply roller that supplies toner to the developing roller 17 and a layer thickness regulating blade that regulates the thickness of the toner supplied to the developing roller 17. The toner corresponding to each color is accommodated.
(3-2-2) Development Operation in Process Unit The toner in the development unit 14 is supplied to a supply roller (not shown), and further supplied to the development roller 17 for development with the supply roller (not shown). The roller 17 is triboelectrically charged to the positive polarity.

The toner supplied to the developing roller 17 is regulated in thickness by a layer thickness regulating blade (not shown) as the developing roller 17 rotates, and is carried on the surface of the developing roller 17 as a thin layer having a constant thickness. The
On the other hand, the surface of the photosensitive drum 15 is uniformly positively charged by the charging roller 16 as the photosensitive drum 15 rotates, and then exposed by high-speed scanning of a laser beam (see the broken line in FIG. 1) from the scanner unit 9. Is done. As a result, an electrostatic latent image corresponding to the image to be formed on the paper P is formed on the surface of the photosensitive drum 15.

When the photosensitive drum 15 further rotates, the toner that is carried on the surface of the developing roller 17 and is positively charged is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 15. As a result, the electrostatic latent image on the photosensitive drum 15 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 15.
(3-3) Transfer Unit The transfer unit 11 is disposed along the front-rear direction in the main body casing 2 above the paper feed unit 3 and below the process unit 10. The transfer unit 11 includes a driving roller 18, a driven roller 19, a transport belt 20 that contacts each photosensitive drum 15, and a transfer roller 21.

The driving roller 18 and the driven roller 19 are opposed to each other with a space in the front-rear direction, and a conveyor belt 20 is wound around them.
The transfer roller 21 is provided so as to face each photosensitive drum 15 with the conveyance belt 20 interposed therebetween.
Then, the paper P fed from the paper feeding unit 3 is transported by the transport belt 20 from the front side to the rear side so as to sequentially pass through the transfer positions where the photosensitive drums 15 and the transfer rollers 21 face each other. Is done. During the conveyance, the toner images of the respective colors carried on the respective photosensitive drums 15 are sequentially transferred onto the paper P to form a color image.
(3-4) Fixing Unit The fixing unit 12 includes a heating roller 22 and a pressure roller 23 facing the heating roller 22, which is disposed behind the transfer unit 11. In the transfer unit 11, the color image transferred onto the paper P is heat-fixed on the paper P by being heated and pressed while the paper P passes between the heating roller 22 and the pressure roller 23. .
(4) Paper discharge The paper P on which the toner image has been fixed passes through a paper discharge path (not shown) consisting of a U-turn path and is conveyed toward the paper discharge roller 24. The paper is discharged onto a paper discharge tray 25 formed on the upper surface of the paper.
2. Details of Process Unit FIG. 2 is an explanatory diagram for explaining the process unit in FIG.

As described above and shown in FIG. 2, the process unit 10 includes a process frame 13, a photosensitive drum 15, and a developing unit 14.
The process frame 13 includes a pair of left and right side plates 33 arranged to face each other with a gap, a front beam 35, a rear beam 34 and a partition plate 36 installed between the side plates 33, and a rack rod 37 as an example of a working member. And.

Both side plates 33 (hereinafter, when referring to the left-right direction of the both side plates 33, the left side plate 33 is the left side plate 33L, and the right side plate 33 is the right side plate 33R. In FIG. 2, the right side plate 33R is notched. Is formed in a substantially rectangular shape in a side view.
Further, the both side plates 33 include a protrusion 63 and a first guide boss 39.
The ridges 63 are formed over almost all of the front-rear direction so as to protrude outward in the left-right direction continuously from the upper end edges of the side plates 33. Further, the lower end edge of the front end portion of the protrusion 63 is inclined upward as it goes forward.

The first guide boss 39 is disposed on the lower side of the ridge 63 above the rear end portion of the both side plates 33 and is formed in a columnar shape protruding from the left and right outer surfaces of the both side plates 33 toward the outer side in the left and right directions. .
The left side plate 33L supports a drum coupling fitting hole (not shown) for supporting a coupling portion (not shown) of the photosensitive drum 15 and a developing coupling portion 52 (described later). A developing coupling fitting hole 38 is formed.

The right side plate 33R is formed with a developing guide groove 42, a rack rod support portion 43, and a drum shaft insertion hole 60 (see FIG. 6).
The development guide groove 42 has a substantially Y-shape in a side view opened so that the upper side expands on the left surface of the right side plate 33R, and is formed so as to accept a development guide boss 51 (described later).

The rack basket support portion 43 is a protrusion protruding leftward at the lower end portion of the left surface of the right side plate 33R, and is formed over substantially the entire front-rear direction. The rack rod support part 43 supports the rack rod 37 from below.
The drum shaft insertion holes 60 are arranged in parallel at intervals in the front-rear direction so as to correspond to the respective photosensitive drums 15 at the lower end portion of the right side plate 33R (see FIG. 6). Further, each drum shaft insertion hole 60 is formed in a substantially circular shape in a side view that is slightly larger in diameter than the diameter of the drum shaft 46 (described later) so that the drum shaft 46 (described later) of each photosensitive drum 15 can be received. ing.

The front beam 35 is provided between the front end portions of the side plates 33 and is formed in a substantially U shape in a side sectional view with the front side opened. Further, the lower side of the right end portion of the front beam 35 is cut out so as to be able to receive the upper end edge of the rack cage 37.
The rear beam 34 is provided between the rear end portions of the side plates 33 and is formed in a substantially V shape in a side sectional view with its lower side opened. Further, the lower side of the right end portion of the rear beam 34 is cut out so as to be able to receive a rack rod 37 and a compression spring 50 (described later).

The rear beam 34 includes a reference shaft fitting portion 40, a contact guide plate 58, and a rear gripping portion 57.
One reference shaft fitting portion 40 is disposed at each of both end portions in the left-right direction at the upper end portion of the rear beam 34. Further, the reference shaft fitting portion 40 protrudes rearward from the rear end edge of the rear beam 34, and is formed in a substantially bowl shape in side view with the lower side opened.

The abutting guide plate 58 is formed in a substantially right-angled triangular shape in a side view, with the lower end protruding below the right side plate 33 </ b> R and spaced from the right side plate 33 </ b> R below the right end portion of the rear beam 34. The contact guide plate 58 guides the rack rod 37 to slide in the front-rear direction.
The rear side gripping part 57 is disposed substantially at the center in the left-right direction and is gripped when the process unit 10 is attached or detached.

  The partition plate 36 is formed in a substantially V shape in a side sectional view with its lower side opened, and three partition plates 36 are arranged in parallel with a space in the front-rear direction between the front beam 35 and the rear beam 34. Thus, the space surrounded by the front beam 35, the rear beam 34, and the side plates 33 is divided into approximately four equal parts in the front-rear direction by the three partition plates 36. Further, the lower side of the right end portion of the partition plate 36 is cut out so as to be able to receive the upper end edge of the rack cage 37.

  The rack rod 37 has a length extending from the rear end portion of the contact guide plate 58 to the front of the foremost photosensitive drum 15 and extends along the front-rear direction. The rack portion 44 and the contact portion 45 are integrated with each other. In preparation. The rack rod 37 is slidable along the front-rear direction on the rack rod support portion 43 of the right side plate 33R so that the contact portion 45 is disposed between the contact guide plate 58 and the right side plate 33R. It is supported.

Four rack portions 44 are formed at the upper end edge of the rack cage 37 at intervals in the front-rear direction. The rack portion 44 is disposed corresponding to each photosensitive drum 15. The rack portion 44 has a number of teeth corresponding to a gear portion 49 (described later) of the shutter 32 (described later) and is configured to mesh with the gear portion 49 (described later).
The abutting portion 45 is disposed at the rear end portion of the rack cage 37, and is formed in a substantially right triangle shape in a side view in which a lower end portion protrudes rearward. Further, the upper end edge of the contact portion 45 is formed so as to protrude above the upper end edge of the rack cage 37. Moreover, the contact part 45 is provided with the contact surface 61 which inclines below as it goes back.

A drum shaft 46 is inserted into each photosensitive drum 15 so as to be relatively rotatable. Each photosensitive drum 15 is equipped with a shutter 32 as an example of a shutter member.
The drum shaft 46 is disposed along the left-right direction inside the photosensitive drum 15 so as to share the central axis with the photosensitive drum 15.
A coupling portion (not shown) that transmits driving to the photosensitive drum 15 is connected to the left end portion of the drum shaft 46 so as to be rotatable relative to the drum shaft 46.

A coupling portion (not shown) of the photosensitive drum 15 is rotatably fitted in a drum coupling fitting hole (not shown) of the left side plate 33L. Further, the right end portion of the drum shaft 46 is fitted in the drum shaft insertion hole 60 of the right side plate 33R. As a result, the photosensitive drum 15 is rotatably supported by the process frame 13.
The shutter 32 is integrally provided with a covering portion 47, a support portion 48, and a gear portion 49 as an example of an actuated member. As will be described in detail later, the shutter 32 is in a closed position (see FIG. 3) that covers the photosensitive drum 15 from below, and an open position (see FIG. 3) that is disposed in front of the photosensitive drum 15 and exposes the lower surface of the photosensitive drum 15. 5)).

The covering portion 47 has a plate shape extending in the left-right direction, and is formed in a circular arc shape along the outer peripheral surface of the photosensitive drum 15.
The support portion 48 extends continuously from the left and right edges of the covering portion 47 toward the drum shaft 46 of the photosensitive drum 15.
The gear portion 49 is formed in a substantially cylindrical shape protruding rightward from the right end edge of the right support portion 48. Further, the gear portion 49 is formed with gear teeth about 2/3 rounds from the bottom to the rear in a side view when the shutter 32 is disposed at the closed position. The gear portion 49 also functions as an example of a gear.

Further, the shutter 32 is formed with a through hole 62 that can receive the drum shaft 46 of the photosensitive drum 15 so as to share the center axis with the gear portion 49 and penetrate the gear portion 49 and the support portion 48 in the left-right direction. Has been.
The drum shaft 46 of the photosensitive drum 15 is inserted into the through hole 62 so as to be rotatable from the inner side in the left-right direction. Thereby, the shutter 32 is supported by the photosensitive drum 15 so as to be swingable.

A compression spring 50 as an example of a first urging member is disposed between the contact portion 45 of the rack rod 37 and the rear beam 34.
The compression spring 50 has a front end connected to the rear beam 34 and a rear end connected to the rack rod 37. Thereby, the rack basket 37 is always urged toward the rear with respect to the process frame 13.

  When the rack 37 is disposed at the rearmost position (a position where the rear end portion overlaps the rear end portion of the contact guide plate 58 when projected in the left-right direction), the shutter 32 is disposed in the closed position. Is done. When the shutter 32 is disposed at the closed position, each gear portion 49 meshes with the front end portion of the corresponding rack portion 44, and each covering portion 47 is disposed below the corresponding photosensitive drum 15. As a result, the lower side of the photosensitive drum 15 is covered.

On the other hand, when the rack 37 is slid forward against the urging force of the compression spring 50, the gear portion 49 that meshes with the rack portion 44 rotates forward (clockwise as viewed from the right side), and the shutter 32 has the gear portion. According to the rotation of 49, it rotates clockwise in the right side view and is arranged at the open position (see FIG. 5).
When the shutter 32 is disposed at the open position, the gear portion 49 meshes with the rear end portion of the rack portion 44, and the covering portion 47 is disposed on the front side of the photosensitive drum 15. As a result, the lower side of the photosensitive drum 15 is exposed.

When the rack 37 is slid rearward by the urging force of the compression spring 50, the gear portion 49 that meshes with the rack portion 44 rotates in the reverse direction (counterclockwise when viewed from the right side). According to the rotation, it rotates counterclockwise as viewed from the right side and is arranged at the closed position (see FIG. 3).
Further, a guide shaft 41 is penetrated through the front end portion of the process frame 13 in the left-right direction.

Both ends of the guide shaft 41 protrude from the both side plates 33 outward in the left-right direction. Further, a front gripping portion 56 is swingably provided at a substantially center in the left-right direction of the guide shaft 41.
The front side grip 56 is always suspended below the guide shaft 41 by gravity. When the process unit 10 is attached or detached, the process unit 10 is gripped by swinging clockwise with the guide shaft 41 as a fulcrum when viewed from the right side.

The development unit 14 includes a development guide boss 51 and a development coupling portion 52.
The development guide boss 51 is formed in a cylindrical shape that protrudes rightward from the left end surface of the development unit 14. Further, the developing guide bosses 51 are arranged in parallel on the upper end portion and the lower end portion of the developing unit 14, respectively, with a space in the vertical direction.

The development coupling unit 52 is provided at the left end of the development unit 14 and transmits a driving force to the development unit 14.
In the developing unit 14, the developing roller 17 is lowered so that the developing coupling portion 52 is fitted into the developing coupling fitting hole 38 of the left side plate 33L and each developing guide boss 51 is fitted into the developing guide groove 42. From the upper side, it is mounted on the process frame 13. Further, the developing unit 14 is detached from the process frame 13 by being pulled out upward.
3. Details of Main Body Casing FIG. 3 is an explanatory diagram for explaining the attachment of the process unit to the main body casing, and shows a state in which the rear end portion of the process unit is inserted into the main body casing.

As shown in FIG. 3, the main casing 2 includes a rail 53 and a reference shaft 54.
The rails 53 are provided on the left and right side walls of the main body casing 2, extend along the front-rear direction, and are formed so as to contact the first guide boss 39 of the process unit 10 from below. The rail 53 guides the mounting of the process unit 10 on the main casing 2.
Further, the rear end portion of the rail 53 is bent so as to incline downward toward the rear.

The front end of the rail 53 is provided with a second guide boss 64 that is in contact with the protrusion 63 from below above the rail 53, and can receive the guide shaft 41 below the rail 53. 65 is formed (see FIG. 5).
The second guide boss 64 is formed in a columnar shape that protrudes inward in the left-right direction from the left and right side walls of the main casing 2 (see FIG. 5).

The guide shaft accommodating portion 65 is partitioned into a substantially rectangular shape in a side view by protrusions protruding inward in the left-right direction from the left and right side walls of the main body casing 2 (see FIG. 5).
The reference shaft 54 is formed in a rod shape extending in the left-right direction, is disposed so as to be continuous with the rear end portion of the rail 53, and is spanned between the left and right side walls of the main body casing 2.
The fixing unit 12 includes a contact plate 55 as an example of a contact member.

The contact plate 55 is disposed on the upper right side of the fixing unit 12 and has a substantially rectangular shape in side view. Further, the contact plate 55 protrudes rearward from the front end edge of the fixing unit 12 so as to contact the contact portion 45 of the process unit 10. Further, an inclined surface 66 is formed at the lower end portion of the contact plate 55 so as to go downward as it goes rearward.
4). FIG. 4 and FIG. 5 are explanatory diagrams for explaining the mounting of the process unit to the main body casing, and FIG. 4 shows a state in which the process unit is disposed at the contact position. FIG. 5 shows a state in which the process unit is arranged at the mounting position. FIG. 6 is a right side view of the process unit in a state corresponding to FIG. FIG. 7 is a right side view of the process unit in a state corresponding to FIG.

In order to attach the process unit 10 to the main casing 2, as shown in FIG. 6, the front grip 56 and the rear grip 57 are gripped so that the first guide boss 39 gets over the second guide boss 64. The rear end portion of the process unit 10 is inserted into the main casing 2.
At this time, the first guide boss 39 is disposed on the rear side of the second guide boss 64 and is in contact with the rail 53 from above. Further, the second guide boss 64 is in contact with the protrusion 63 from below. Moreover, as shown in FIG. 3, the shutter 32 is arrange | positioned in a closed position, and the rack cage | basket 37 has advanced backward.

Next, the front side gripping portion 56 is gripped, and the process unit 10 is pushed backward with respect to the main body casing 2.
Then, as shown in FIG. 4, the contact portion 45 of the rack cage 37 contacts the contact plate 55 of the fixing unit 12 from the front side, and the process unit 10 is disposed at the contact position. Thereby, the rack rod 37 receives a reaction directed forward from the contact plate 55 and slides forward against the urging force of the compression spring 50.

Then, when the gear portion 49 that meshes with the rack portion 44 rotates forward (clockwise as viewed from the right side), the shutter 32 rotates clockwise as viewed from the right side, and is disposed at the open position. As a result, the lower side of the photosensitive drum 15 is exposed.
Next, the front gripping portion 56 is gripped, and the process unit 10 is pushed further rearward.

Then, as shown in FIG. 7, the first guide boss 39 goes obliquely forward and downward along the inclination of the rail 53, and the rear end portion of the protrusion 63 is obliquely forward while contacting the second guide boss 64. It goes downward and comes off the second guide boss 64. When the reference shaft 54 is fitted into the reference shaft fitting portion 40, the process unit 10 is arranged at the mounting position.
At this time, as shown in FIG. 5, the abutting surface 61 of the abutting portion 45 heads diagonally forward and downward while abutting against the inclined surface 66 of the abutting plate 55. Thereby, the process unit 10 is moved from the contact position to the mounting position in a state where the contact plate 55 and the rack rod 37 are in contact, that is, in a state where the rack rod 37 is slid forward. For this reason, the shutter 32 is disposed in the open position while the process unit 10 is moved from the contact position to the mounting position, and does not interfere with the transport belt 20.

When the process unit 10 is arranged at the mounting position, each photosensitive drum 15 is brought into contact with the transport belt 20 from above, and the mounting of the process unit 10 on the main casing 2 is completed.
The front cover 5 is provided with a lock member 26 so as to be fitted to the guide shaft 41. When the front cover 5 is closed, the lock member 26 is fitted to the guide shaft 41 and the process frame 13. The front end of is positioned.
5). Operation and Effect (1) According to the color laser printer 1, as shown in FIGS. 3 and 5, when the process unit 10 is detached from the main casing 2, the shutter 32 is disposed at the closed position. When the process unit 10 is mounted on the main casing 2 and the process unit 10 is slid with respect to the main casing 2, the rack 37 provided in the process unit 10 is provided in the fixing unit 12 inside the main casing 2. It contacts the contact plate 55 from the front, slides forward due to the reaction from the contact plate 55, and rotates the gear portion 49 of the shutter 32 in the forward direction. Thereby, the shutter 32 can be moved to the open position.

Therefore, when the process unit 10 is detached from the main casing 2, the shutter 32 can be placed in the closed position, and the shutter 32 can be moved to the open position by attaching the process unit 10 to the main casing 2.
As a result, the photosensitive drum 15 can be protected when the process unit 10 is detached from the main casing 2.
(2) According to the color laser printer 1, the rack rod 37 is always slid rearward by the urging force of the compression spring 50.

Therefore, when the process unit 10 is detached from the main casing 2 and the contact between the rack 37 and the contact plate 55 is released, the shutter 32 can be automatically moved to the closed position.
As a result, the photosensitive drum 15 can be reliably protected when the process unit 10 is detached from the main casing 2.
(3) Further, according to the color laser printer 1, as shown in FIGS. 4 and 5, the process unit 10 is configured so that the contact plate 55 and the rack rod 37 are in contact at the contact position. It moves from the contact position to the mounting position while maintaining the contact, and is mounted on the main casing 2.

At that time, the shutter 32 is disposed in the open position while the process unit 10 moves from the contact position to the mounting position so as not to interfere with the transport belt 20.
Therefore, the shutter 32 is disposed at the closed position until the process unit 10 is disposed at the contact position, and is moved to the open position when the process unit 10 is disposed at the contact position, and remains disposed at the open position. The process unit 10 can be moved from the contact position to the mounting position.

As a result, the photosensitive drum 15 is moved from when the process unit 10 is detached from the main casing 2 until just before the photosensitive drum 15 and the transport belt 20 come into contact (until the process unit 10 is disposed at the contact position). Can be protected.
Further, the shutter 32 is moved to the open position so as not to interfere with the conveyor belt 20.
Therefore, it is possible to prevent the conveyance belt 20 from being damaged due to the interference between the shutter 32 and the conveyance belt 20.
(4) Also, according to the color laser printer 1, as shown in FIG. 2, a shutter 32 having a gear portion 49 is attached to each photosensitive drum 15, and each photosensitive drum 15 is attached to the process frame 13. It is supported.

Therefore, in the configuration in which each photosensitive drum 15 is supported by the process frame 13, each photosensitive drum 15 can be protected.
(5) Also, according to this color laser printer 1, when the rack rod 37 slides in the front-rear direction when the process unit 10 is attached or detached, the rack portion 44 of the rack rod 37 acts on the gear portion 49, and the gear portion 49 is moved to the right side. Turn it clockwise (forward rotation) or counterclockwise (reverse rotation). Thereby, the shutter 32 can be moved to an open position or a closed position.

Therefore, the shutter 32 can be moved to the open position or the closed position in conjunction with attachment / detachment of the process unit 10 to / from the main body casing 2 with a simple configuration.
(6) Moreover, according to this color laser printer 1, as shown in FIG. 2, the gear part 49 and the rack part 44 are provided in the right side.
Therefore, it is not necessary to provide the gear part 49 and the rack part 44 on the left side, and the number of parts can be reduced.
6). Second Embodiment FIG. 8 is an explanatory diagram for explaining a process unit in a second embodiment.

9-11 is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 2nd Embodiment, FIG. 9 is the state by which the rear-end part of the process unit was inserted in the main body casing, FIG. 10 shows a state where the process unit is arranged at the contact position, and FIG. 11 shows a state where the process unit is arranged at the mounting position.
FIG. 12 is a right side view of the process unit in a state corresponding to FIG. FIG. 13 is a right side view of the process unit in a state corresponding to FIG.

8 to 13, members similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.
In the first embodiment, the photosensitive drum 15 and the charging roller 16 are supported on the process frame 13, and the developing unit 14 is detachably attached to the process frame 13 (see FIG. 2).

However, as shown in FIG. 8, a process cartridge 71 that integrally includes the developing unit 14, the photosensitive drum 15, and the charging roller 16 may be detachably provided to the process frame 13.
That is, the process unit 70 includes four process cartridges 71 and a process frame 13 that accommodates each process cartridge 71.

The process cartridge 71 includes a process casing 72, the developing unit 14 that is integrally supported by the process casing 72, the photosensitive drum 15, and the charging roller 16.
The process housing 72 includes a substantially box-shaped upper portion extending in the left-right direction and a lower portion extending downward from the upper portion. The lower part is provided with a pair of process side plates 73 arranged to face each other with a gap in the left-right direction. A process guide boss 74 is formed at the right end of the upper portion.

Both process side plates 73 are formed in a substantially arm shape in side view that bulges rearward (see FIG. 9).
The process guide boss 74 is formed in a cylindrical shape that protrudes rightward from the right end surface of the developing unit 14. The process guide boss 74 is disposed above the drum shaft 46 of the photosensitive drum 15.

The developing unit 14 is an upper portion of the process casing 72 and includes a developing roller 17 as in the first embodiment.
The photosensitive drum 15 is disposed adjacent to the developing unit 14 below the developing unit 14 and is supported between the process side plates 73. The photosensitive drum 15 is provided with a shutter 32 as in the first embodiment, and the gear portion 49 of the shutter 32 functions as an example of a second engagement portion.

The charging roller 16 is supported between the process side plates 73 behind the photosensitive drum 15.
As in the first embodiment, the process frame 13 includes a pair of left and right side plates 33 that are opposed to each other with a gap therebetween, a front beam 35, a rear beam 34, and a partition plate 36 that are installed between the side plates 33. And a rack 37 that is slidable in the direction. The rack portion 44 of the rack cage 37 functions as an example of the first engagement portion. A process guide groove 75 is formed in the right side plate 33R.

The process guide groove 75 is cut out from the upper edge of the right side plate 33R downward in a substantially Y shape in a side view with the upper side opened (see FIG. 12). The process guide groove 75 receives the drum shaft 46 and the process guide boss 74 of the photosensitive drum 15 and guides the mounting of the process cartridge 71 on the process frame 13.
The process cartridge 71 is mounted on the process frame 13 from above with the photosensitive drum 15 facing down so that the drum shaft 46 and the process guide boss 74 of the photosensitive drum 15 are fitted in the process guide groove 75.

When the process cartridge 71 is mounted on the process frame 13, the gear portion 49 meshes with the rack portion 44.
Further, the process cartridge 71 is detached from the process frame 13 by being pulled upward.
The process unit 70 can be attached to the main casing 2 in the same manner as in the first embodiment.

Specifically, as shown in FIG. 12, the rear end portion of the process unit 70 is inserted into the main casing 2.
At this time, as shown in FIG. 9, the shutter 32 is disposed at the closed position, and the rack rod 37 has advanced backward.
Next, the front side gripping portion 56 is gripped, and the process unit 70 is pushed backward with respect to the main body casing 2.

Then, as shown in FIG. 10, the process unit 70 is disposed at the contact position, and the contact portion 45 of the rack cage 37 contacts the contact plate 55 of the fixing unit 12 from the front side. Thereby, the rack rod 37 receives a reaction directed forward from the contact plate 55 and slides forward against the urging force of the compression spring 50.
Then, when the gear portion 49 that meshes with the rack portion 44 rotates forward (clockwise as viewed from the right side), the shutter 32 rotates clockwise as viewed from the right side, and is disposed at the open position.

Next, the front gripping portion 56 is gripped and the process unit 70 is pushed further rearward.
Then, as shown in FIG. 13, the first guide boss 39 goes obliquely forward and downward along the slope of the rail 53, and the rear end portion of the protrusion 63 is obliquely forward while contacting the second guide boss 64. It goes downward and comes off the second guide boss 64. When the reference shaft 54 is fitted into the reference shaft fitting portion 40, the process unit 70 is disposed at the mounting position.

At this time, as shown in FIG. 11, the process unit 70 is in a state where the contact plate 55 and the rack 37 are in contact, that is, the rack 37 is slid forward, and the shutter 32 is disposed at the open position. In a state where it is kept, it is moved from the contact position to the mounting position.
When the process unit 70 is arranged at the mounting position, each photosensitive drum 15 is brought into contact with the transport belt 20 from above, and the mounting of the process unit 70 on the main casing 2 is completed.

According to this color laser printer 1, as shown in FIG. 8, the process unit 70 includes a process cartridge 71 including a photosensitive drum 15 in a detachable manner, and the process cartridge 71 includes a gear portion 49 and a shutter 32. Yes.
Therefore, in the configuration in which the photosensitive drum 15 is provided in the process cartridge 71, the photosensitive drum 15 can be protected.

Further, according to the color laser printer 1, when the process cartridge 71 is mounted on the process unit 70, the rack portion 44 and the gear portion 49 provided in the rack cage 37 are engaged with each other.
Thereby, when the process cartridge 71 is attached to the process unit 70 and the process unit 70 is attached to the main casing 2, the rack cage 37 acts on the gear portion 49 via the rack portion 44.

Therefore, when the process cartridge 71 is detached from the process unit 70 and when the process unit 70 is detached from the main casing 2, the shutter 32 is disposed in the closed position, and the process unit 70 is attached to the main casing 2. The shutter 32 can be moved to the open position by the mounting operation.
As a result, the photosensitive drum 15 can be protected when the process cartridge 71 is detached from the process unit 70 and when the process unit 70 is detached from the main casing 2.
7). Third Embodiment FIGS. 14A and 14B are explanatory diagrams for explaining a process unit according to the third embodiment, in which FIG. 14A is a state where the shutter is disposed at the closed position, and FIG. 14B is a state where the shutter is disposed at the open position. Indicates the state that has been performed.

15A is a side view corresponding to FIG. 14A, and FIG. 15B is a side view corresponding to FIG. 14B.
16-18 is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 3rd Embodiment, FIG. 16 is the state by which the rear-end part of the process unit was inserted in the main body casing, FIG. 17 shows a state where the process unit is arranged at the contact position, and FIG. 18 shows a state where the process unit is arranged at the mounting position.

FIG. 19 is a left side view of the process unit in a state corresponding to FIG. FIG. 20 shows a left side view of the process unit in a state corresponding to FIG.
14 to 20, members similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.
In the first embodiment, the process unit 10 includes a rack rod 37 as an example of an action member, and a gear portion 49 as an example of an actuated member (see FIG. 2).

However, as shown in FIG. 14, the process unit 80 may include a linear motion cam 82 as an example of an action member, and may include an arm 83 as an example of an action member.
As shown in FIGS. 14A and 14B, the process unit 80 includes a developing unit 14, a photosensitive drum 15, and a process frame 81 as in the first embodiment.

At each left end of each photosensitive drum 15, a drum coupling 96 that transmits driving to the photosensitive drum 15 is connected so that relative rotation with respect to the photosensitive drum 15 is restricted and rotates together with the photosensitive drum 15. .
The process frame 81 includes a linear motion cam 82 as an example of a reciprocating member, a pair of left and right arms 83 as an example of an actuated member, and a shutter 84 as an example of a shutter member.

As shown in FIGS. 14A and 14B, the side plates 33 each include a linear cam guide 85 and an arm support boss 86, respectively.
The linear cam guide 85 is a flat plate having a substantially rectangular shape in side view extending in the front-rear direction, and is disposed between the developing unit 14 and the photosensitive drum 15 in the vertical direction. In addition, a guide groove 97 that is partitioned by a ridge extending outward in the left-right direction is formed at the center in the vertical direction of the linear cam guide 85 and extends along the front-rear direction. A semicircular arm support 98 is formed at the upper end of the guide groove 97 above the front end of the photosensitive drum 15.

The arm support boss 86 is formed in a cylindrical shape that protrudes outward in the left-right direction, and is disposed in the arm support portion 98.
In addition, a drum coupling cover 87 for supporting a drum coupling 96 (described later) of the photosensitive drum 15 is formed on the left side plate 33L.
The drum coupling cover 87 is formed with a positioning portion 88 as an example of a holding portion (see FIG. 14B). The positioning portion 88 is disposed obliquely below the front side of the drum coupling cover 87 and has a circular arc shape when viewed from the side.

As shown in FIGS. 15A and 15B, the linear cam 82 is a flat plate extending in the front-rear direction, and is spaced by 4 in the front-rear direction so as to correspond to each photosensitive drum 15. In addition, a bulging portion 99 that bulges downward is provided. A fitting hole 89 is formed in the bulging portion 99.
The fitting hole 89 is formed in a substantially inverted L shape when viewed from the side. Specifically, the fitting hole 89 extends in the front-rear direction and is bent 90 degrees downward at the front end portion thereof. Further, the fitting hole 89 includes a first position on the rear end portion upper side and a second position on the lower side of the front end portion, and between the first position and the second position, The lower end edge is formed with an inclined portion 100 that is inclined backward as it goes upward.

Each arm 83 has a bar shape extending in the vertical direction, and both end portions in the vertical direction are formed in a circular arc shape when viewed from the side. Further, the arm 83 has a first insertion hole 90 formed at the upper end, a second insertion hole 91 formed at the lower end, and an arm swinging boss between the first insertion hole 90 and the second insertion hole 91. 92 is formed.
The first insertion hole 90 is formed to have a diameter slightly larger than the outer diameter of the arm support boss 86 so that the arm support boss 86 can be received.

The second insertion hole 91 is formed with substantially the same diameter as the first insertion hole 90.
The arm swing boss 92 is formed in a cylindrical shape and protrudes outward in the left-right direction.
As shown in FIGS. 14A and 14B, the shutter 84 is integrally formed with a covering portion 101, a pair of left and right shutter swing bosses 93, and a stopper portion 94 (see FIG. 15A). I have. As will be described in detail later, the shutter 84 is disposed at a closed position (see FIG. 14A) that covers the photosensitive drum 15 from below and in front of the photosensitive drum 15, and exposes the lower surface of the photosensitive drum 15. It is provided so as to move to an open position (see FIG. 14B).

Further, a paper guide 95 is formed on the lowermost surface of the covering portion 101 in the foremost shutter 84.
The covering portion 101 has a plate shape extending in the left-right direction, and is formed in a circular arc shape along the outer peripheral surface of the photosensitive drum 15.
Each shutter swing boss 93 has a cylindrical shape and is formed so as to protrude outward in the left-right direction from both left and right end portions of the front end portion of the covering portion 101.

The stopper portion 94 is a ridge formed in the left and right direction at the rear end portion of the covering portion 101, and protrudes upward from the upper surface of the covering portion 101 (see FIG. 15A).
The paper guide 95 is a ridge extending along the front-rear direction, and its lower end edge is formed in a substantially rectangular shape in side view. A plurality of paper guides 95 are arranged in parallel in the left-right direction (see FIG. 14A), and are formed on the entire lower surface of the covering portion 101. The paper guide 95 guides the paper P between the photosensitive drum 15 and the transport belt 20 when the process unit 80 is mounted on the main casing 2 and forms an image. That is, the foremost shutter 84 also serves as a guide member.

  Then, as shown in FIGS. 15A and 15B, the arm support boss 86 is fitted in the first insertion hole 90 so as to be rotatable from the inner side in the left-right direction. Thereby, each arm 83 is provided to be swingable with respect to the process frame 81. Further, the shutter swing boss 93 is fitted in the second insertion hole 91 so as to be swingable from the inner side in the left-right direction. Thereby, the shutter 84 is supported between the arms 83 so as to be swingable.

The process frame 81 includes a first coil spring 102 as an example of a second urging member.
The first coil spring 102 is wound around the arm support boss 86, and one end is locked to the arm 83 and the other end is locked to the process frame 81. Thereby, the arm 83 is always urged clockwise by the urging force of the first coil spring 102 about the arm support boss 86 as a fulcrum. That is, the arm 83 is always urged by the urging force of the first coil spring 102 so that the shutter 84 is disposed at the closed position.

The shutter 84 includes a second coil spring 103 as an example of a third urging member.
The second coil spring 103 is wound around the shutter swing boss 93, one end is locked to the arm 83, and the other end is locked to the cover plate 101. Thereby, the shutter 84 is always urged clockwise by the urging force of the first coil spring 102 around the shutter swing boss 93 as a fulcrum. That is, the shutter 84 is always urged toward the photosensitive drum 15 in the closed position by the urging force of the first coil spring 102.

Further, the linear cam 82 is slidably fitted in the guide groove 97 so that the arm swinging boss 92 is loosely fitted in the fitting hole 89 from the inner side in the left-right direction, outside the arm 83 in the left-right direction. Yes.
A compression spring 104 as an example of a first urging member is disposed in the guide groove 97 on the front side of the linear cam 82.

The compression spring 104 has a front end connected to the linear motion cam guide 85 and a rear end connected to the linear motion cam 82. Thereby, the linear motion cam 82 is always urged rearward with respect to the process frame 81.
When the linear cam 82 is slid forward against the urging force of the compression spring 104, the arm swing boss 92 is pressed against the inclined portion 100 of the fitting hole 89, and the arm 83 swings forward. To do. Then, the arm swing boss 92 is disposed from the second position to the first position along the inclined portion 100. As a result, the shutter 84 is retracted forward in accordance with the swing of the arm 83 and disposed at the open position (see FIG. 15B).

When the shutter 84 is disposed at the open position, the lower side of the photosensitive drum 15 is exposed.
When the linear cam 82 is slid rearward by the urging force of the compression spring 104, the arm 83 swings rearward by the urging force of the first coil spring 102. Then, the arm swing boss 92 is disposed from the first position to the second position along the inclined portion 100. Thereby, the shutter 84 is retracted rearward according to the swing of the arm 83 and is disposed at the closed position (see FIG. 15B).

At this time, the lower end portion of the arm 83 is held by the positioning portion 88. Thereby, the swing of the arm 83 is restricted. The stopper portion 94 is in contact with the drum coupling cover 87. As a result, the shutter 84 is disposed to face the photosensitive drum 15 with a space therebetween.
In addition, after the linear motion cam 82 and the arm 83 are attached to the process frame 81, the linear motion cam cover 105 is externally fitted to the linear motion cam guide 85 from the outside in the left-right direction (see FIG. 19). The linear cam 82 and the arm 83 are fixed to the process frame 81 in the left-right direction by the linear cam cover 105.

The process unit 80 can be attached to the main casing 2 in the same manner as in the first embodiment.
Specifically, as shown in FIG. 19, the rear end portion of the process unit 80 is inserted into the main casing 2.
At this time, as shown in FIG. 16, the shutter 84 is disposed at the closed position, and the linear motion cam 82 advances rearward.

Next, the front side gripping portion 56 is gripped, and the process unit 80 is pushed backward with respect to the main body casing 2.
Then, as shown in FIG. 17, the rear end portion of the linear motion cam 82 comes into contact with the contact plate 55 of the fixing unit 12 from the front side, and the process unit 80 is arranged at the contact position. Thereby, the linear cam 82 receives a reaction directed forward from the contact plate 55 and slides forward against the urging force of the compression spring 104.

At this time, the arm swinging boss 92 is pressed against the inclined portion 100 of the fitting hole 89, and the arm 83 swings forward. Then, the arm swing boss 92 is disposed from the second position to the first position along the inclined portion 100. Thus, the shutter 84 is retracted forward in accordance with the swing of the arm 83 and is disposed at the open position. As a result, the lower side of the photosensitive drum 15 is exposed.
Next, the front gripping portion 56 is gripped and the process unit 80 is pushed further rearward.

  Then, as shown in FIG. 20, the first guide boss 39 is directed forward and downward along the inclination of the rail 53, and the rear end portion of the protrusion 63 is in contact with the second guide boss 64 at the inclination. Heading diagonally forward and downward while coming into contact, the second guide boss 64 comes off. When the reference shaft 54 is fitted into the reference shaft fitting portion 40, the process unit 80 is arranged at the mounting position.

  Further, at this time, as shown in FIG. 18, the rear end portion of the linear motion cam 82 heads obliquely downward and forward while contacting the inclined surface 66 of the contact plate 55. Thereby, the process unit 80 is moved from the contact position to the mounting position in a state where the contact plate 55 and the linear cam 82 are in contact with each other, that is, in a state where the linear cam 82 is slid forward. . Therefore, the shutter 84 is disposed in the open position while the process unit 80 is moved from the contact position to the mounting position, and does not interfere with the transport belt 20.

When the process unit 80 is disposed at the mounting position, each photosensitive drum 15 is brought into contact with the transport belt 20 from above, and the mounting of the process unit 80 on the main casing 2 is completed.
According to this color laser printer 1, as shown in FIG. 18, the foremost shutter 84 also serves as a guide member for guiding the paper P between the photosensitive drum 15 and the transport belt 20.

Therefore, it is not necessary to provide a separate guide member, and the number of parts can be reduced.
Further, according to this color laser printer 1, as shown in FIGS. 16, 17, and 18, the linear motion cam 82 is formed with the fitting hole 89 including the first position and the second position, and the process unit 80 An arm swinging boss 92 is provided on an arm 83 that is swingably supported by the arm 83, and the arm swinging boss 92 is fitted in the fitting hole 89.

  The linear motion cam 82 slides when the process unit 80 is attached / detached, thereby acting on the arm 83 via the arm swing boss 92 to swing the arm 83. When the arm 83 is swung so that the arm swinging boss 92 is disposed at the first position, the shutter 84 is moved to the open position, and the arm 83 is disposed such that the arm swinging boss 92 is disposed at the second position. Is swung, the shutter 84 moves to the closed position.

Therefore, the shutter 84 can be moved to the open position or the closed position in conjunction with the attachment / detachment of the process unit 80 with respect to the main body casing 2 with a simple configuration.
Further, according to this color laser printer 1, as shown in FIG. 15A, the arm swinging boss 92 and the fitting hole 89 are loosely fitted, so that the arm swinging boss 92 is in the first position. When moving between the second position and the second position, it is possible to move while retreating appropriately to the play portion of the fitting hole 89.

Therefore, the arm 83 can be smoothly swung, and the shutter 84 can be smoothly moved to the open position or the closed position.
Further, according to the color laser printer 1, as shown in FIGS. 15A and 15B, the arm 84 is always placed in the closed position by the urging force of the first coil spring 102. Oscillate as shown. Further, due to the biasing force of the second coil spring 103, the shutter 84 always moves toward the photosensitive drum 15 in the closed position.

Therefore, when the process unit 80 is detached from the main casing 2 and the contact between the linear cam 82 and the contact plate 55 is released, the shutter 84 can be automatically moved to the closed position. In addition, in the closed position, the photosensitive drum 15 and the shutter 84 can be opposed to each other.
As a result, the photosensitive drum 15 can be reliably protected when the process unit 80 is detached from the main casing 2.

Further, according to the color laser printer 1, as shown in FIG. 15B, the lower end portion of the arm 83 is held by the positioning portion 88 when the shutter 84 is disposed at the closed position.
Therefore, the swing of the arm 83 can be restricted at the position where the shutter 84 is disposed at the closed position.

As a result, the shutter 84 can be reliably disposed at the closed position.
Further, according to the color laser printer 1, as shown in FIG. 14A, the arm 83 supports both ends of the shutter 84 in the longitudinal direction of the photosensitive drum 15.
Therefore, the shutter 84 can be reliably supported in the longitudinal direction of the photosensitive drum 15.

Further, according to this color laser printer 1, the shutter 84 is provided with the stopper portion 94 provided at the end opposite to the end connected to the arm 83 in the closed position, and the drum coupling cover 87 of the process unit 80. To be opposed to the photosensitive drum 15 with a gap.
Therefore, it is possible to prevent the shutter 84 from interfering with the photosensitive drum 15 when the shutter 84 is disposed at the closed position.

1 is a side sectional view showing a first embodiment of a color laser printer as an example of an image forming apparatus of the present invention. It is explanatory drawing for demonstrating the process unit in FIG. It is explanatory drawing for demonstrating mounting | wearing of the process unit to a main body casing, Comprising: The state which inserted the rear-end part of the process unit in the main body casing is shown. It is explanatory drawing for demonstrating mounting | wearing of the process unit to a main body casing, Comprising: The process unit is arrange | positioned in the contact position. It is explanatory drawing for demonstrating mounting | wearing of the process unit to a main body casing, Comprising: The process unit is arrange | positioned in the mounting position. FIG. 4 shows a right side view of the process unit in a state corresponding to FIG. 3. FIG. 6 shows a right side view of the process unit in a state corresponding to FIG. 5. It is explanatory drawing for demonstrating the process unit in 2nd Embodiment. It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 2nd Embodiment, Comprising: The state which the rear-end part of the process unit was inserted in the main body casing is shown. It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 2nd Embodiment, Comprising: The process unit has been arrange | positioned in the contact position. It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 2nd Embodiment, Comprising: The process unit has been arrange | positioned in the mounting position. FIG. 10 is a right side view of the process unit in a state corresponding to FIG. 9. FIG. 12 is a right side view of the process unit in a state corresponding to FIG. 11. It is explanatory drawing for demonstrating the process unit in 3rd Embodiment, (a) shows the state in which the shutter was arrange | positioned in the closed position, (b) shows the state in which the shutter was arrange | positioned in the open position. (A) is a side view corresponding to FIG. 14 (a), and (b) is a side view corresponding to FIG. 14 (b). It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 3rd Embodiment, Comprising: The state which the rear-end part of the process unit was inserted in the main body casing is shown. It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 3rd Embodiment, Comprising: The process unit has been arrange | positioned in the contact position. It is explanatory drawing for demonstrating mounting | wearing of the process unit to the main body casing in 3rd Embodiment, Comprising: The process unit has been arrange | positioned in the mounting position. FIG. 17 is a left side view of the process unit in a state corresponding to FIG. 16. FIG. 19 is a left side view of the process unit in a state corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color laser printer 2 Main body casing 10 Process unit 15 Photosensitive drum 20 Conveyance belt 32 Shutter 37 Rack rod 44 Rack part 45 Contact part 46 Gear part 50 Compression spring 55 Contact plate 70 Process unit 71 Process cartridge 80 Process unit 82 Direct motion Cam 83 Arm 84 Shutter 88 Positioning portion 89 Fitting hole 92 Arm swing boss 94 Stopper portion 102 First coil spring 103 Second coil spring 104 Compression spring

Claims (15)

Device body,
A drawer member that houses a plurality of photoconductors arranged in parallel at intervals and is slidably attached to the apparatus main body;
A shutter member that moves between a closed position for covering the photoconductor and an open position for exposing the photoconductor;
An actuated member connected to the shutter member for moving the shutter member to the open position or the closed position;
An action member provided on the drawer member so as to be slidable along the parallel direction and acting on the actuated member by sliding; and
An image forming apparatus, comprising: an abutting member that is provided inside the apparatus main body, abuts against the action member when the drawer member is mounted, and slides the action member.   2. The first biasing member that biases the action member in a direction opposite to a contact direction of the contact member with respect to the action member when the drawer member is mounted. Image forming apparatus. In the inside of the apparatus main body, an endless belt that contacts the photoconductor,
The drawer member is
A contact position where the contact member and the action member contact each other;
It can be moved to a mounting position where the mounting to the apparatus main body is completed,
The contact member and the action member are moved from the contact position to the mounting position in contact with each other,
The shutter member is moved to the open position while the drawer member is moved from the contact position to the mounting position so as not to interfere with the endless belt. The image forming apparatus described in 1.   The shutter member on the most upstream side in the mounting direction of the drawer member also serves as a guide member for guiding an image forming member on which an image is formed between the photosensitive member and the endless belt. Item 4. The image forming apparatus according to any one of Items 1 to 3. The drawer member is
Each of the photoconductors is rotatably supported,
The image forming apparatus according to claim 1, further comprising the actuated member and the shutter member. The actuated member includes a gear that can rotate forward and backward,
The action member includes a rack portion that meshes with the gear,
The image forming apparatus according to claim 5, wherein the gear moves the shutter member to the open position or the closed position by rotating forward or backward.   The image forming apparatus according to claim 5, wherein the gear and the rack portion are provided on one side in the longitudinal direction of the photoconductor. The action member includes a reciprocating member that is slidable in the parallel direction,
The actuated member includes an arm member that supports the shutter member;
The reciprocating member is formed with a fitting hole including a first position and a second position,
The arm member is
At one end, it is swingably supported by the drawer member,
Connected to the shutter member at the other end,
Between the one end portion and the other end portion, provided with a fitting portion fitted into the fitting hole,
The reciprocating member is
By disposing the fitting portion at the first position, the shutter member is moved to the open position,
The image forming apparatus according to claim 5, wherein the shutter member is moved to the closed position by disposing the fitting portion at the second position.   The image forming apparatus according to claim 8, wherein the fitting portion is loosely fitted in the fitting hole. A second biasing member that biases the arm member so that the shutter member is always disposed at the closed position;
The image forming apparatus according to claim 8, further comprising a third urging member that urges the shutter member so that the shutter member is always directed toward the photoconductor in the closed position.   The pull-out member includes a holding portion that holds the other end portion of the arm member when the shutter member is disposed at the closed position. An image forming apparatus according to claim 1.   The image forming apparatus according to claim 8, wherein the arm member supports both end portions of the shutter member in a longitudinal direction of the photosensitive member. The shutter member includes a stopper portion at an end opposite to the end connected to the arm member,
13. The stopper portion abuts against the drawer member when the shutter member is disposed at a closed position, and causes the shutter member to face the photoconductor with a space therebetween. The image forming apparatus according to any one of the above. The drawer member is detachably provided with a process cartridge including the photoconductor,
The image forming apparatus according to claim 1, wherein the process cartridge includes the actuated member and the shutter member. The action member includes a first engagement portion,
The actuated member includes a second engagement portion that engages with the first engagement portion,
The image forming apparatus according to claim 14, wherein the first engaging portion and the second engaging portion are engaged when the process cartridge is mounted on the drawer member.

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