JP2023030291A - Image forming apparatus - Google Patents

Abstract

To prevent a belt from being left unmounted to improve workability.SOLUTION: An image forming apparatus comprises: a top cover that closes or opens an opening formed in an upper part of the image forming apparatus; a cartridge that is removably attached to the image forming apparatus and has a photoreceptor; exposure means that is held on the top cover and exposes the photoreceptor; a belt that is removably attached to the image forming apparatus from the opening with the cartridge removed from the image forming apparatus; a guide that is provided opposite to a longitudinal direction of the photoreceptor and guides the cartridge removably attached to the image forming apparatus; and a regulation member that is rotatable between a regulation position for regulating the movement of the cartridge and a retreat position for releasing the regulation of the movement of the cartridge. The regulation member is engaged with the belt mounted in the image forming apparatus and is rotated from the regulation position to the retreat position according to an operation to mount the belt, and is rotated from the retreat position to the regulation position by an urging force of an urging member in association with an operation to remove the belt from the image forming apparatus.SELECTED DRAWING: Figure 4

Description

The present invention relates to image forming apparatuses such as copiers and printers that form images on sheets.

An example of a conventional image forming apparatus is disclosed in Japanese Patent Application Laid-Open No. 2002-200012. The image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200010 includes an endless belt having a substantially horizontal belt surface and circulating inside an apparatus main body provided with a conveying path for conveying sheets, and a and four cartridges facing each other and arranged in the longitudinal direction of the belt surface. The cartridge is a unit in which a photoreceptor, developing means, and the like are integrated.

An openable and closable top cover is provided on the top surface of the main body of the image forming apparatus so as to cover the top of the cartridge. The top cover is rotatable about a shaft provided on the rear side of the device main body along the left-right direction, and is displaceable to an open position in which the front end is rotated upward to assume an inclined posture. It's becoming A scanner section for exposing the photoreceptor in the cartridge is held inside the top cover. By opening the top cover, the upper part of the cartridge is opened, and each cartridge can be attached and detached through the opening formed in the upper part of the apparatus main body.

JP-A-2006-98776

However, in the image forming apparatus disclosed in Patent Document 1, when removing the belt from the main body of the apparatus in order to replace the belt or clear a paper jam, it is necessary to open the top cover and remove all the cartridges. be. Moreover, if the cartridges are installed in a state where the user has forgotten to install the belt, it is necessary to remove all the installed cartridges and then install the belt, resulting in poor workability.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent forgetting to attach a transfer belt and improve workability.

A representative configuration of the present invention for achieving the above object is an image forming apparatus for forming an image on a sheet, the image forming apparatus being rotatable about a rotation shaft with respect to the image forming apparatus. a top cover movable between a first position for closing an opening formed in an upper portion of an image forming apparatus and a second position for opening the opening; a cartridge having a photoreceptor; exposure means held by the top cover for exposing the photoreceptor; and an endless belt disposed below the cartridge, with the cartridge removed. a belt that can be attached to and detached from the image forming apparatus through the opening, and a guide that is provided opposite to the photoreceptor in the longitudinal direction of the photoreceptor and guides a cartridge that is attached to and detached from the image forming apparatus through the opening; A regulating member that is rotatable about a support shaft, and that enters into a region where guides facing each other in the longitudinal direction of the photoreceptor overlap, and that the cartridge is attached to the image forming apparatus. a restricting position for restricting movement of the cartridge along the guide by coming into contact with the guide; wherein the regulating member is positioned at the regulating position by being biased by an urging member in a state in which the belt is removed from the image forming apparatus, and the regulating member is positioned with respect to the image forming apparatus It engages with the attached belt, is rotated about the support shaft from the regulated position to the retracted position by the operation of attaching the belt, and is accompanied by the operation of removing the belt from the image forming apparatus. It is characterized in that it is rotated from the retracted position to the restricted position with the support shaft as a fulcrum by the biasing force of the force member.

According to the present invention, since the cartridge cannot be attached to the apparatus main body when the belt is not attached, it is possible to prevent forgetting to attach the belt and improve workability. In addition, since the restricting member is rotatable, the position of the regulating member can be smoothly moved by the rotation associated with the attachment and detachment of the belt.

Schematic diagram of a color printer Illustration showing a color printer with the top cover open FIG. 4 is a diagram showing a guide member and an interlocking member before the transfer belt is attached according to the first embodiment; 3 is a perspective view showing a guide member and an interlocking member before the transfer belt is attached according to the first embodiment; FIG. FIG. 4 is a diagram showing a guide member and an interlocking member after the transfer belt is attached according to the first embodiment; FIG. 2 is a relational diagram showing an exposure head, a photosensitive drum, a guide member, and an interlocking member according to the first embodiment; FIG. 11 is a diagram showing a guide member and an interlocking member before the transfer belt is attached according to the second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following examples should be appropriately changed according to the configuration of the device to which the present invention is applied and various conditions. They are not intended to limit the scope of the invention only to them.

[Example 1]
An image forming apparatus according to a first embodiment will be described with reference to FIGS. 1 to 6. FIG. Here, an electrophotographic image forming apparatus (color printer) will be exemplified as the image forming apparatus.

FIG. 1 is a schematic configuration diagram of a color printer, and FIG. 2 is a diagram showing the color printer with its top cover opened. FIG. 3 is a diagram showing the guide member and the interlocking member before the transfer belt is attached. FIG. 4 is a perspective view showing the guide member and the interlocking member before the transfer belt is attached. FIG. 5 is a diagram showing the guide member and interlocking member after the transfer belt is attached. FIG. 6 is a diagram showing the positional relationship among the exposure head, the photosensitive drum, the guide member and the regulating member.

In the following description, the direction shown in FIG. 1 will be used. That is, the upper side in FIG. 1 is defined as "upper", and the lower side as "lower". The upper side in FIG. 1 is the upper side in the vertical direction, and the lower side is the lower side in the vertical direction. In addition, the left side in FIG. 1 is defined as "front", the right side as "rear", the back side as "left", and the front side as "right". The left side in FIG. 1 is one side in the first horizontal direction perpendicular to the vertical direction, and the right side is the other side in the first horizontal direction. The back side in FIG. 1 is one side in a second horizontal direction perpendicular to the vertical direction and the first horizontal direction, and the front side is the other side in the second horizontal direction.

As shown in FIG. 1, a color printer 1 as an image forming apparatus includes a main housing 10, which is the main body of the apparatus, a top cover 11, a feeding section 20, and an image forming section 30. As shown in FIG. Also provided in the body housing 10 are a temperature sensor 19 that detects the temperature inside the body housing 10, a patch detection sensor 75 as an example of a sensor, and a control unit 800 that controls the operation of the printer. ing. Further, inside the main housing 10, as shown in FIGS. 3 and 4, a guide member 12 and a regulation member 13 are provided.

The top cover 11 is arranged on the upper part of the main body housing 10, and is provided so as to be rotatable with respect to the main body housing 10 about a rotation shaft 11A on the rear side of the main body housing 10. The opening 10A formed in the upper part is opened and closed. Specifically, the top cover 11 is positioned around the pivot shaft 11A in a first position (shown in FIG. 1) that closes the opening 10A and a second position (shown in FIG. 2) that opens the opening 10A. position).

The feeding unit 20 is provided in the lower part inside the main housing 10 . The feeding unit 20 includes a feeding tray 21 that accommodates paper P as a sheet, and a paper feeding mechanism 22 that supplies the paper P from the feeding tray 21 to the image forming unit 30 . The paper P in the feed tray 21 is separated one by one by the paper supply mechanism 22 and supplied to the image forming section 30 .

The image forming section 30 includes a plurality (here, four) of exposure heads 40 , a plurality (here, four) of process cartridges PC, a transfer unit 70 , and a fixing unit 80 .

An exposure head 40 as exposure means has a light emitting element and an imaging lens at its tip. The exposure head 40 exposes the surface of a cylindrical photosensitive drum 51, which is a photosensitive member, by blinking the light-emitting elements based on image data. The exposure head 40 is held inside the top cover 11 so as to be suspended from the top cover 11 . The exposure head 40 is disposed above the photosensitive drum 51 in the state shown in FIG. 1 with the top cover 11 closed. Specifically, by opening and closing the top cover 11, the exposure head 40 moves to a reference position (position shown in FIG. 1) closer to the photosensitive drum 51 and a retracted position (shown in FIG. 2) farther from the photosensitive drum 51 than the reference position. position shown).

The process cartridge PC has a cylindrical photosensitive drum 51 which is a photosensitive member, and at least one process means acting on the photosensitive drum 51 . The process means includes a charger 52 as charging means, a developing roller 62 as developing means, and a cleaning roller 54 as cleaning means, which will be described later.

Each process cartridge PC is arranged in parallel along the front-rear direction between the top cover 11 and the feed tray 21 . Each process cartridge PC can be attached to and detached from the main housing 10 through the opening 10A in the state shown in FIG. 2 with the top cover 11 opened. Each process cartridge PC is guided and positioned by each guide member 12 (see FIG. 3) provided in the main housing 10 when it is mounted in the main housing 10 . Each process cartridge PC includes a drum unit 50 and a developer cartridge 60 as an example of a developer. The developer cartridge 60 is detachable from the drum unit 50 .

The drum unit 50 includes a cylindrical photosensitive drum 51 that is a photosensitive member, a scorotron charger 52 that charges the photosensitive drum 51, a pressing spring 53 that biases the developing cartridge 60 toward the photosensitive drum 51, and a cleaning roller. 54, and a drum frame 55 that supports the photosensitive drum 51 and the like.

The developer cartridge 60 mainly includes a toner storage portion 61 that stores toner and a development roller 62 that supplies the toner in the toner storage portion 61 to the photosensitive drum 51 . The toner is a developer that develops the electrostatic latent image on the photosensitive drum 51 . The toner containing portion 61 of each developing cartridge 60 contains yellow, magenta, cyan, and black toners in order from the front (left side in FIG. 1).

The transfer unit 70 is a belt unit having a conveyor belt 73 that is an endless belt that is stretched by a drive roller 71 and a driven roller 72 that are stretching members. Here, a configuration is illustrated in which the transfer unit 70, which is a belt unit, has a transport belt 73 that transports the paper P as a sheet.

The transfer unit 70 is arranged below the process cartridge PC and provided between the feed tray 21 and the process cartridge PC. The transfer unit 70 includes a drive roller 71, a driven roller 72, an endless conveying belt 73 as an example of a transfer medium, and four transfer rollers 74 as an example of a transfer device. The conveying belt 73 is stretched between a driving roller 71 and a driven roller 72 which are stretching members. The conveying belt 73 has an outer surface in contact with each photosensitive drum 51 , and each transfer roller 74 is arranged inside the conveying belt 73 so as to sandwich the conveying belt 73 with each photosensitive drum 51 .

The transfer unit 70 can be removed from the main housing 10 with all the process cartridges PC removed. In other words, when detaching the transfer unit 70 from the main body housing 10, the process cartridge PC is first detached. Here, "the state in which the process cartridge PC is removed" means a state in which the process cartridge PC is completely separated from the main housing 10 and removed. In other words, when the state in which the process cartridge PC is fully installed in the main housing 10 (the state in which the image forming operation can be performed) is defined as the installed state, it means the state in which the installation from the installation position is released. not to In other words, the state in which the process cartridge PC is completely removed from the guide member 12 described later is defined as "the state in which the process cartridge PC is removed".

A patch detection sensor 75 is provided obliquely below the rear of the conveying belt 73 . The patch detection sensor 75 is a sensor for detecting the print density of the toner image formed on the transport belt 73 for density correction, and is arranged facing the rear part of the transport belt 73 . In the following description, the toner image for density correction formed on the conveying belt 73 is also referred to as a "patch". The patch detection sensor 75 is a light reflective sensor that includes a light emitting element such as an LED and a light receiving element such as a phototransistor, and irradiates the patch with light to detect the reflected light.

With the top cover 11 opened (see FIG. 2), the transfer unit 70 can be attached and detached through the opening 10A of the main housing 10 after each process cartridge PC is removed. That is, the transfer unit 70 having the transport belt 73 can be attached to and detached from the main housing 10 through the opening 10A in a state in which the process cartridge PC is removed.

The guide member 12 and the regulating member 13 related to attachment/detachment of the process cartridge PC and the transfer unit 70 will be described later.

The fixing unit 80 is provided behind the process cartridge PC and the transfer unit 70 . The fixing unit 80 includes a heating roller 81 and a pressure roller 82 pressed against the heating roller 81 .

In the image forming unit 30 as described above, the surface of the photosensitive drum 51 is uniformly charged by the charger 52 and then exposed by the exposure head 40 . An image is formed. By applying a voltage (development bias) to the developing roller 62 , toner is supplied from the developing roller 62 to the photosensitive drum 51 , and the electrostatic latent image is visualized to form a toner image on the photosensitive drum 51 . be done. That is, the developer cartridge 60 develops the electrostatic latent image on the photosensitive drum 51 .

The toner images formed on the respective photosensitive drums 51 are sequentially superimposed and transferred onto the paper P conveyed on the conveying belt 73 by the transfer rollers 74 . The paper P onto which the toner image has been transferred is conveyed between the heating roller 81 and the pressure roller 82 so that the toner image is thermally fixed. After that, the paper P is discharged from the body housing 10 to the outside by the transport rollers 91 and placed on the discharge tray 11B formed on the top surface of the top cover 11 . Toner remaining on the photosensitive drum 51 after transfer is collected by a cleaning roller 54 .

Next, referring to FIGS. 3 to 6, the guide member 12 and the regulating member 13 provided inside the main housing 10, which are related to attachment and detachment of the process cartridge PC and the transfer unit 70, will be described.

As shown in FIGS. 3 and 4, the color printer 1 includes guide members 12 and regulation members 13 . The guide members 12 are provided facing each other in the longitudinal direction of the photosensitive drum 51 (see FIG. 6). The guide member 12 is a guide that guides the process cartridge PC that is attached to and detached from the main housing 10 through the opening 10A. Although only one guide member 12 is shown here, a guide member 12 having a similar configuration is provided for each process cartridge. In this example, four guide members 12 are arranged in parallel along the front-rear direction shown in FIG.

The restricting member 13 is provided rotatably around the support shaft 16 as a fulcrum. The regulating member 13 is rotatable between a regulating position shown in FIGS. 3 and 4 and a retracted position shown in FIG. As shown in FIGS. 3 and 4, the regulated position is a position where the guide members 12 facing each other in the longitudinal direction of the photosensitive drum 51 overlap each other. The regulating position is a regulating position that abuts on the process cartridge PC mounted on the main housing 10 to regulate the movement of the process cartridge PC along the guide member 12 . On the other hand, the retracted position is a position retracted from the overlapping area, as shown in FIG. The retracted position is a retracted position at which movement restriction of the process cartridge PC is released.

Note that, in this example, the regulating member 13 is provided for one guide member 12 out of the plurality of guide members 12 . More specifically, in FIG. 1, it is provided for one guide member 12 that guides one process cartridge PC on the front side among the process cartridges PC arranged in the front-rear direction.

The restricting member 13 is provided between the guide members 12 facing each other in the longitudinal direction of the photosensitive drum 51 . As with the guide member 12 , the regulating member 13 is provided on both sides of the photosensitive drum 51 in the longitudinal direction as shown in FIG. 6 .

The regulating member 13 has a regulating portion 13B that contacts the process cartridge PC at the regulating position shown in FIGS. Further, the regulating member 13 has a link portion 13A as an engaging portion that can be engaged with the flange portion 70A of the transfer unit 70. As shown in FIG. The regulating member 13 is an interlocking member that is integrally provided with a regulating portion 13B and a link portion 13A and rotates in conjunction with the operation of mounting the transfer unit 70 on the main housing 10 .

The regulating member 13 is urged by an urging member 15 from the retracted position toward the regulating position. The regulating member 13 is biased by the urging member 15 and positioned at the regulating position (the position shown in FIGS. 3 and 4) when the transfer unit 70 is removed from the main housing 10 . At this time, the regulating member 13 enters the overlapping region, and the regulating portion 13B of the regulating member 13 closes the entrance of the guide member 12 . Therefore, the process cartridge PC cannot be moved along the guide member 12 when the transfer unit 70 is removed from the main housing 10 . That is, the process cartridge PC cannot be attached to the main housing 10 before the transfer unit 70 is attached.

The regulating member 13 is urged clockwise about the support shaft 16 by the urging member 15, hits against a stopper (not shown), and is stopped at the regulating position shown in FIG. Here, as a stopper for stopping the regulating member 13 at the regulating position, a configuration in which a separate stopper is provided is exemplified, but the configuration is not limited to this. For example, the restricting member 13 and the guide member 12 may be configured to engage with each other at the restricting position, and the restricting member 13 or the guide member 12 may be configured as a stopper.

Further, as shown in FIG. 6, the restricting portion 13B is positioned outside the conveying belt 73 in the longitudinal direction of the photosensitive drum 51 (horizontal direction, rotation axis direction). 3 and 4, the restricting portion 13B is provided above the support shaft 16. As shown in FIGS. Further, the link portion 13A is provided below the restriction portion 13B. Therefore, the restricting portion 13B does not interfere with the transfer unit 70 attached to the main housing 10, and does not interfere with the operation of attaching the transfer unit 70. FIG. Further, even if the process cartridge PC is mounted while the transfer unit 70 is removed, the process cartridge PC is restricted by the restriction portion 13B and is not engaged with the link portion 13A. Therefore, this configuration can also improve workability.

The regulating member 13 is engaged with the transfer unit 70 attached to the main housing 10, and is retracted from the regulating position shown in FIG. is rotated into position. More specifically, the flange portion 70A of the transfer unit 70 attached to the main housing 10 engages the link portion 13A of the regulating member 13 positioned at the regulating position. Then, as shown in FIG. 5, the flange portion 70A of the transfer unit 70 pushes down the link portion 13A by moving the transfer unit 70 in the arrow D direction (downward, mounting direction). As a result, as the transfer unit 70 moves downward, the regulation member 13 rotates counterclockwise (in the direction of arrow E) around the support shaft 16 as a fulcrum. At this time, the regulating portion 13B of the regulating member 13 moves from the position (position shown in FIG. 3) in which the regulating portion 13B of the regulating member 13 overlaps the overlapping region (position shown in FIG. 5) to the position retreated from the overlapping region (position shown in FIG. 5). rotated. In this manner, in conjunction with the operation of mounting the transfer unit 70 on the main housing 10, the regulating portion 13B of the regulating member 13 is moved to the position where the regulation of movement of the process cartridge PC from the entrance of the guide member 12 is released. be evacuated. Therefore, it is possible to mount the process cartridge PC to the main housing 10 through the entrance of the guide member 12 . The timing of starting the “mounting operation (moving operation)” here means the timing when the transfer unit 70 comes into contact with the link portion 13</b>A of the regulation member 13 . Also, the timing at which the “mounting operation” ends means the timing at which the rotation of the restricting member 13 stops. In other words, it is not necessary to regard the moment when a part of the transfer unit 70 approaches the opening 10A as the timing when the "mounting operation" starts.

On the other hand, as the transfer unit 70 is removed from the main housing 10, the regulating member 13 moves from the retracted position shown in FIG. 5 to the regulating position shown in FIG. rotated. That is, as the transfer unit 70 moves in the direction opposite to the direction of arrow D shown in FIG. direction (the direction opposite to the direction of arrow E). At this time, the regulating portion 13B of the regulating member 13 moves from the position (position shown in FIG. 5) at which the regulating portion 13B of the regulating member 13 is retracted from the overlapping region (position shown in FIG. 5) to the position (position shown in FIG. 3) at which it enters the overlapping region. rotated. In this manner, in conjunction with the operation of removing the transfer unit 70 from the main housing 10, the regulating portion 13B of the regulating member 13 is rotated to the position where movement of the process cartridge PC from the entrance of the guide member 12 is regulated. . Therefore, as shown in FIG. 4, the restricting portion 13B of the restricting member 13 blocks the entrance of the guide member 12, and the process cartridge PC cannot be installed before the transfer unit 70 is installed.

Further, the regulating member 13 has a shape along the guide surface 12a of the guide member 12 that guides the process cartridge PC at the retracted position shown in FIG. This configuration prevents interference with the process cartridge PC guided along the guide member 12 . Further, even if the regulating member 13 is provided for another guide member 12, the regulating member 13 is retracted into the space between the guide members 12 adjacent in the front-rear direction. There is no interference with the process cartridge PC guided along.

Further, as shown in FIG. 6, the exposure head 40 exposes the image forming area of the photosensitive drum 51 . The guide member 12 and the regulating member 13 are arranged outside the image forming area of the photosensitive drum 51 in the horizontal direction of the main housing 10 and further outside the exposure head 40 . Therefore, the guide member 12 and the regulating member 13 do not interfere with the exposure head 40 when the top cover 11 is opened and closed, and do not hinder the movement of the top cover 11 and the exposure head 40 .

As described above, by rotating the regulating member 13 to the regulating position or the retracted position in conjunction with the insertion/removal of the transfer unit 70, the regulating member 13 can perform the operation of mounting the process cartridge PC when the transfer unit 70 is not mounted. It is designed to regulate. Therefore, the process cartridge PC cannot be attached before the transfer unit 70 is attached to the main housing 10 . Therefore, forgetting to attach the transfer unit 70 is eliminated, and workability can be improved. Further, since the regulating member 13 is rotatably provided, its position can be smoothly moved by the rotation accompanying the attachment/detachment operation of the transfer unit 70 .

Further, the restricting portion 13B and the link portion 13A are integrally provided as the restricting member 13, and close only the entrance of the frontmost guide member 12. As shown in FIG. Therefore, the parts can be made compact, the number of parts can be reduced, the cost can be reduced, and workability can be improved without forgetting to attach the transfer unit 70 .

In this embodiment, the restricting member 13 restricts entry into one guide member 12 out of the plurality of guide members 12, but the present invention is not limited to this. The restricting member 13 may restrict entry of all the process cartridges into the guide member when the transfer unit 70 is not attached. Alternatively, the entry of any one or more process cartridges into the guide member may be restricted without being limited to one. In this embodiment, the restricting member 13 is provided on both sides of the main housing 10 in the longitudinal direction of the photosensitive drum 51. However, the restricting member 13 is not limited to this, and can be provided only on one side. It is good also as a structure provided.

[Example 2]
A second embodiment of the present invention will be described below with reference to FIG. FIG. 7 is a diagram showing the guide member and the regulating member before the transfer belt is attached.

In this embodiment, the configuration of the restricting portion 13B of the restricting member 13 is different from that of the above-described embodiment. Since the configuration of the regulating member 13 other than the regulating portion 13B is the same as that of the above-described embodiment, description thereof is omitted. In addition, in the following description, the same reference numerals are used for the components having the same configuration as those of the first embodiment, and the description thereof is omitted.

As shown in FIG. 7, the regulating portion 13B of the regulating member 13 has an acute angle α between the contact surface 13B1 with the process cartridge PC and the direction of insertion of the process cartridge PC (direction of arrow F). It is.

At the regulating portion 13B where the angle α is an obtuse angle, the force (arrow F) toward the insertion direction of the process cartridge PC becomes a vector that acts on the contact surface 13B1 of the regulating portion 13B in the counterclockwise direction. That is, there is a possibility that the force (arrow F) in the insertion direction of the process cartridge PC acts as a force (vector) that rotates the regulating member 13 from the regulating position toward the retracted position. In this case, when the angle .alpha. is around 90 degrees, the magnitude of the force acting on the restricting member is usually small, so it is at a level that does not pose a problem of counterclockwise rotation. Even so, if the process cartridge PC is forcibly inserted, it may open.

Therefore, in this embodiment, the regulating portion 13B of the regulating member 13 is arranged so that the angle α between the abutment surface 13B1 with the process cartridge PC and the insertion direction (arrow F direction) of the process cartridge PC is an acute angle. there is As a result, the force (arrow F) in the insertion direction of the process cartridge PC becomes a vector (arrow G) that acts clockwise on the contact surface 13B1 of the restricting portion 13B. That is, the force (arrow F) in the insertion direction of the process cartridge PC acts as a force (vector) that rotates the regulating member 13 from the retracted position toward the regulating position. As a result, even if the process cartridge PC is forcibly inserted, the restricting member 13 will not be rotated to the retracted position retracted from the guide member 12 .

As described above, in this embodiment as well, it is not possible to mount the frontmost process cartridge PC before the transfer unit 70 is mounted. Therefore, forgetting to attach the transfer unit 70 is eliminated, and workability can be improved. Further, since the regulating member 13 is rotatably provided, its position can be smoothly moved by the rotation accompanying the attachment/detachment operation of the transfer unit 70 . Further, even if the regulating member 13 receives a force in the insertion direction of the process cartridge at the regulating position, the regulating member 13 will not be rotated to the retracted position.

[Other embodiments]
Although four process cartridges are used in the above-described embodiment, the number of process cartridges to be used is not limited, and may be appropriately set as required.

In the above-described embodiment, the process integrally includes a photosensitive drum as a cartridge detachably attachable to the body of the image forming apparatus, and charging means, developing means, and cleaning means acting on the photosensitive drum as process means. A cartridge is illustrated. However, it is not limited to this. In addition to the photosensitive drum, a cartridge integrally including any one of charging means, developing means, and cleaning means may be used.

Furthermore, in the above-described embodiment, the cartridge including the photosensitive drum is detachably attached to the main housing, but the present invention is not limited to this. For example, a structure in which the photosensitive drum and each process means are respectively detachable may be used.

Further, in the above-described embodiments, a printer is used as an example of the image forming apparatus, but the present invention is not limited to this. For example, other image forming apparatuses such as copiers, facsimile machines, etc., or other image forming apparatuses such as multifunction machines combining these functions may be used. Similar effects can be obtained by applying the present invention to these image forming apparatuses.

In the above-described embodiments, a conveying belt for conveying a sheet is exemplified as a belt, and an image forming apparatus is exemplified in which toner images of respective colors are successively superimposed and transferred onto a sheet carried by the conveying belt, but the present invention is limited to this. not to be The belt may be an intermediate transfer belt (intermediate transfer member) that once carries the toner image formed on each photosensitive drum. An image forming apparatus may be used in which toner images of respective colors are sequentially superimposed and transferred onto the intermediate transfer belt, and the toner images carried on the intermediate transfer belt are collectively transferred onto a sheet. Similar effects can be obtained by applying the present invention to such an image forming apparatus.

P...Paper PC...Process cartridge 1...Color printer 10...Main housing 10A...Opening 11...Top cover 11A...Rotating shaft 12...Guiding member 12a...Guiding surface 13...Regulating member 13A...Link part 13B...Regulating part 13B1... Contact surface 15 Biasing member 16 Support shaft 30 Image forming unit 40 Exposure head 50 Drum unit 51 Photosensitive drum 52 Charger 60 Development cartridge 61 Toner storage unit 62 Development roller 70 Transfer unit 70A ...flange portion 71 ...driving roller 72 ...driven roller 73 ...conveyor belt 80 ...fixing unit

Claims (7)

An image forming apparatus for forming an image on a sheet,
A first position for closing an opening formed in an upper portion of the image forming apparatus, and a second position for opening the opening. a top cover movable to the
a cartridge detachable from the image forming apparatus through the opening and having a photoreceptor;
an exposure unit held by the top cover for exposing the photoreceptor;
an endless belt disposed below the cartridge, the belt being attachable to and detachable from the image forming apparatus through the opening when the cartridge is removed;
guides provided facing each other in the longitudinal direction of the photoreceptor for guiding cartridges to be attached to and detached from the image forming apparatus through the opening;
A regulating member that is rotatable about a support shaft, and that enters into a region where guides facing each other in the longitudinal direction of the photoreceptor overlap, and that the cartridge is attached to the image forming apparatus. a restricting position for restricting movement of the cartridge along the guide by coming into contact with the guide;
with
the regulating member is positioned at a regulating position by being biased by a biasing member in a state in which the belt is removed from the image forming apparatus;
The regulating member engages with the belt mounted on the image forming apparatus, and is rotated from the regulating position to the retracted position about the support shaft by the operation of mounting the belt, and the image forming apparatus. When the belt is removed from the belt, the belt is rotated from the retracted position to the restricted position with the support shaft as a fulcrum by the biasing force of the biasing member.
An image forming apparatus characterized by: The regulating member has a regulating portion that contacts the cartridge at the regulating position to regulate movement of the cartridge along the guide, and an engaging portion that can be engaged with the belt,
the restricting portion is positioned outside the belt in the longitudinal direction of the photoreceptor and is provided above the support shaft;
The engaging portion is provided below the restricting portion,
2. The image forming apparatus according to claim 1, wherein: The regulating portion of the regulating member has an acute angle α formed between a contact surface with the cartridge and an insertion direction of the cartridge,
3. The image forming apparatus according to claim 2, wherein: The image forming apparatus has a plurality of detachable cartridges, and includes a plurality of guides for guiding each cartridge to be detached from the image forming apparatus through the opening,
The regulating member is provided for one guide out of each guide,
4. The image forming apparatus according to claim 1, wherein: The regulating member has a shape along a guide surface of the guide that guides the cartridge at the retracted position.
5. The image forming apparatus according to claim 1, wherein: 6. The image forming apparatus according to claim 1, wherein the guide and the regulating member are provided outside an image forming area of the photoreceptor and outside the exposing means. . 7. The image forming apparatus according to claim 1, wherein the regulating member is provided on both sides in the longitudinal direction of the photoreceptor.

Images