JP2007171305A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which positional accuracy of a photoreceptor is secured and the attaching and detaching operation of a process cartridge can be easily performed. <P>SOLUTION: The image forming apparatus has: a process cartridge 10Y having a photoreceptor 1; a positioning portion 401 for positioning the photoreceptor 1, when it comes into contact with an intermediate transfer body 5; and a holding means 30 for holding the process cartridge 10Y so as to be in contact with and separated from the intermediate transfer body 5. The image forming apparatus has springs 231Y and 241Y for separating the process cartridge 10Y from the holding member 30 and holding the process cartridge 10Y, when the photoreceptor 1 is positioned by the positioning portion 401. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  When the process unit is inserted from the front of the image forming apparatus main body, a guide rail having a guide groove is generally used, but it is not easy to insert the process unit aiming at the guide rail. In particular, in an apparatus in which process cartridges are arranged obliquely, the insertion guides overlap, which makes it more difficult.

  On the other hand, in an image forming apparatus having a tandem configuration, the photoconductor must be accurately positioned with respect to the intermediate transfer member in order to prevent image defects such as color misregistration. In order to solve this problem, Patent Document 1 proposes a support member having a guide portion that supports a process cartridge from below and a process cartridge positioning method.

JP 2004-221986 A

  However, in the technique disclosed in Patent Document 1, the positional accuracy of the unit after mounting depends on the support member, and it is difficult to ensure the positional accuracy due to an increase in intervening parts. Particularly in the configuration in which the process cartridge is separated, the guide member that supports the process cartridge is also movable, and the guide member itself must be positioned, which is complicated.

  In addition, there has been proposed a method for securing positional accuracy by mounting an openable positioning frame. However, the replacement work becomes complicated, and the positioning of the frame becomes necessary by making the positioning frame movable. .

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that can ensure the positional accuracy of the photosensitive member and can easily attach and detach the process cartridge. is there.

  The object is to hold a process cartridge having a photoconductor, a positioning portion for positioning the photoconductor when the photoconductor comes into contact with the intermediate transfer body, and the process cartridge to be able to contact and separate from the intermediate transfer body. An image forming apparatus having a holding member can be achieved by an image forming apparatus including an elastic member that holds the process cartridge apart from the holding member when the photosensitive member is positioned by the positioning portion.

  With this configuration, when the process cartridge having the photosensitive member comes into contact with the intermediate transfer member, the process cartridge is held away from the holding member by the elastic member, and therefore, regardless of the positional accuracy between the photosensitive member and the holding member. Therefore, it is possible to ensure the positional accuracy of the photosensitive member when contacting the intermediate transfer member.

  The process cartridge includes a developing device that develops a toner image on the photosensitive member, and the holding member separates the photosensitive member from the intermediate transfer member and causes the process cartridge to be attached to the image forming apparatus. The image forming apparatus can be detachably held.

  With this configuration, the process cartridge can be replaced. Further, as described above, since the positional accuracy of the photosensitive member when contacting the intermediate transfer member can be ensured regardless of the positional accuracy between the photosensitive member and the holding member, the position of the process cartridge relative to the holding member can be secured. It can be set gently. Thereby, the user can easily perform the process cartridge attaching / detaching operation.

  Further, it can be achieved by an image forming apparatus provided with a positioning plate that contacts the process cartridge and positions the photoconductor when the photoconductor is positioned by the positioning unit.

  With this configuration, the process cartridge can be easily attached and detached, and the positional accuracy of the photosensitive member when contacting the intermediate transfer member can be further improved.

The holding member can also be achieved by an image forming apparatus that holds a plurality of the process cartridges.
With this configuration, the detachability of the process cartridge is improved.

The plurality of process cartridges can also be achieved by an image forming apparatus arranged in an inclined manner with respect to the horizontal direction.
With this configuration, the image forming apparatus main body can be made compact.

  According to the present invention, it is possible to provide an image forming apparatus capable of ensuring the positional accuracy of the photosensitive member and easily attaching and detaching the process cartridge.

  Hereinafter, embodiments of the invention according to the present application will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram showing an outline of an image forming apparatus according to the present invention. The image forming apparatus includes four process cartridges 10Y, 10M, 10C, and 10K that form yellow, magenta, cyan, and black toner images, and each has an endless belt shape so as to face each of these process cartridges. The intermediate transfer member 5 is supported and the peripheral surface is driven to rotate.

  Each process cartridge has a photoconductor 1 on which an electrostatic latent image is formed. The process cartridge is formed on the photoconductor 1 with a charging device (not shown) that charges the surface of the photoconductor almost uniformly. A developing device (not shown) that selectively transfers toner to the latent image to form a toner image.

  A secondary transfer roll 11 is arranged on the downstream side of the position where the process cartridge of the intermediate transfer body 5 is opposed to the sheet, and the secondary transfer portion is arranged to face the recording paper from the sheet tray 12 through the conveyance path 13. Is transported. A fixing device 14 that heats and pressurizes the toner image to press the toner image onto the recording paper is provided upstream of the secondary transfer portion in the recording paper conveyance path, and the toner image is fixed further downstream. A paper discharge tray 15 for storing the recording paper is provided. On the other hand, the intermediate transfer member 5 is opposed to the intermediate transfer member 5 on the downstream side in the circumferential direction in order to collect toner remaining without being transferred onto the recording paper or patches that are not secondarily transferred in the secondary transfer unit. A cleaning device 16 is provided.

  Each process cartridge includes a developing device (not shown) that selectively transfers toner to a latent image formed on the photoreceptor 1 to form a toner image. The image forming apparatus also includes a charging device (not shown) that charges the surface of the photoconductor substantially uniformly around each photoconductor 1, and scans the surface of the photoconductor 1 with laser light to form an electrostatic latent image. An optical scanning device (not shown) for writing is provided. Further, inside the intermediate transfer member 5, a transfer charger 6 that primarily transfers the toner image on the photosensitive member 1 onto the intermediate transfer member 5, a drive roll 7, a plurality of support rolls 8, and a secondary transfer roll. A transfer facing roll 9 is arranged at a position where 11 faces.

  The intermediate transfer member 5 is stretched between a drive roll 7 and a transfer counter roll 9. The drive roll 7 can be driven in the normal direction or in the reverse direction, and the intermediate transfer member 5 is driven in the normal direction (arrow direction shown in the figure) or in the reverse direction following the drive of the drive roll 7. It is designed to move around.

  The process cartridges 10Y, 10M, 10C, and 10K are held by the holding member 20. A slide groove 201 is formed in the holding member 20, and an engagement pin 202 that engages with the slide groove 201 is formed on the main body device side. The cam member 30 is formed to be rotatable about the cam shaft 301. Further, the cam member 30 contacts the holding member 20. When the cam member 30 is rotated halfway from the state shown in FIG. 1, the holding member 20 moves along the slide groove 201, and the photosensitive member 1 provided in the process cartridge comes into contact with the intermediate transfer member 5. With such a configuration, the photosensitive member 1 is held in contact with and separated from the intermediate transfer member 5. The positioning member 40 will be described later.

  Next, the configuration around the process cartridge will be described. FIG. 2 is a diagram showing a configuration around the process cartridge. The process cartridge 10Y will be described as an example, but the other process cartridges 10M, 10C, and 10K have the same configuration.

  The process cartridge 10Y is held by a guide 21Y formed on the holding member 20. A support surface 22Y for supporting and guiding the process cartridge 10Y from below is formed on the guide 21Y. The supporting surfaces of the guides for guiding the other process cartridges have different heights corresponding to the positions of the process cartridges.

  The guide 21Y has a first recess 23Y formed on the bottom surface, and a spring (elastic member) 231Y is installed in the first recess 23Y. The spring 231Y is installed in the vertical direction. The end of the spring 231Y is bonded to the first recess 23Y, and the other end is bonded to a spherical roller 232Y having good slidability.

  Further, a storage portion 101Y is formed on the bottom surface of the process cartridge 10Y at a position facing the recess 23Y formed in the guide 21Y. The roller 232Y is stored in the storage unit 101Y.

  The guide 21Y has a second recess 24Y formed on the side surface, and a spring (elastic member) 241Y is installed in the second recess 24Y. The spring 241Y is installed in the horizontal direction. The end of the spring 241Y is bonded to the second recess 24Y, and the pressing member 242Y is bonded to the other end. The process cartridge 10Y is biased leftward by the spring 241Y through the pressing member 242Y, and the process cartridge 10Y is held in contact with the side wall 25Y on the side facing the side surface where the second recess 24Y is formed. The

  Next, the configuration around the process cartridge when the photosensitive member 1 contacts the intermediate transfer member 5 will be described.

  As described above, when the cam member 30 shown in FIG. 1 rotates halfway, the holding member 20 moves so that the photoreceptor 1 provided in each process cartridge contacts the intermediate transfer member 5. When the photosensitive member 1 abuts against the intermediate transfer member 5, a positioning portion (not shown) formed on the process cartridge 10Y is pressed against the positioning portion 401 formed on the positioning member 40 shown in FIG. The cartridge 10Y is positioned and the photosensitive member 1 is positioned.

  Even if the positioning portion of the process cartridge 10Y comes into contact with the positioning portion 401, the holding member 20 moves along the slide groove 201 in the direction in which the intermediate transfer body 5 is further provided. For this reason, the guide 21Y also moves in the direction in which the intermediate transfer member 5 is provided. However, the process cartridge 10Y is held at a predetermined position by the positioning portion and the positioning portion 401 formed on the process cartridge 10Y. Accordingly, the guide 21Y further moves while the process cartridge 10Y is positioned by the positioning portion.

FIG. 3 is a view showing a configuration around the process cartridge when it is positioned.
As the holding member 20 further moves, the guide 21Y moves to the left with respect to the process cartridge 10Y. Therefore, the roller 232Y stored in the storage unit 101Y similarly moves to the left with respect to the process cartridge 10Y, and the roller 232Y comes off the storage unit 101Y and comes into contact with the bottom surface 102Y of the process cartridge 10Y. At this time, the process cartridge 10Y is urged in the vertical direction by the spring 231Y via the roller 232Y. The bottom surface of the process cartridge 10Y is separated from the support surface 22Y and is held by a spring 231Y.

  As the holding member 20 moves, the spring 241Y is compressed, and the process cartridge 10Y is urged to the left via the pressing member 242Y. The pressing member 242Y is formed so as not to contact the guide 21Y.

  Accordingly, the process cartridge 10Y is held away from the holding member 20 and held by the springs 231Y and 241Y when the photosensitive member 1 contacts the intermediate transfer member 5. With this configuration, when the photosensitive member 1 contacts the intermediate transfer member 5, the process cartridge 10Y is held away from the holding member 20 by the springs 231Y and 241Y, so that the positional accuracy between the photosensitive member 1 and the holding member 20 is maintained. Regardless of this, the positional accuracy of the photosensitive member 1 when contacting the intermediate transfer member 5 can be ensured.

  Further, the holding member 20 separates the photosensitive member 1 from the intermediate transfer member 5, and a process cartridge having a developing device (not shown) for developing the toner image on the photosensitive member 1 and the photosensitive member 1 is used as an image forming apparatus. Hold it detachably.

Specifically, the process cartridges 10Y, 10M, 10C, and 10K shown in FIG. 1 are configured to be detachable in a direction perpendicular to the paper surface.
With this configuration, the process cartridge can be replaced. Further, as described above, since the positional accuracy of the photosensitive member 1 when contacting the intermediate transfer member 5 can be ensured regardless of the positional accuracy of the photosensitive member 1 and the holding member 20, The position of the process cartridge can be set gently. Thereby, the user can easily perform the process cartridge attaching / detaching operation.

Further, since the photosensitive member 1 is separated from the intermediate transfer member 5 and the process cartridge is exchanged, the surface of the photosensitive member 1 and the intermediate transfer member 5 are rubbed with each other when the process cartridge is exchanged. Can prevent lighting.
Moreover, since the holding member 20 holds a plurality of process cartridges, the detachability of the process cartridge is improved.
Further, since the plurality of process cartridges are arranged to be inclined with respect to the horizontal direction, the main body of the image forming apparatus can be made compact.

  Next, Example 2 will be described with reference to FIGS. The basic configuration of the operating device 10A is the same as that of the operating device 10 according to the first embodiment. Therefore, the same parts as those of the controller device 10 are denoted by the same reference numerals, and redundant description is omitted. FIG. 4 is a diagram illustrating a peripheral configuration of the process cartridge according to the second embodiment. FIG. 5 is a diagram illustrating a configuration around the process cartridge according to the second embodiment when positioned.

  As shown in FIG. 4, the positioning plate 26Y is fixed on the support surface 22Y of the guide 21Y. The positioning plate 26Y is fixed on a support surface 22Y that does not come into contact with the process cartridge 10Y when the photosensitive member 1 and the intermediate transfer member 5 are separated from each other. That is, the positioning plate 26Y is fixed on the support surface 22Y on the side where the second recess 24Y is formed.

  As shown in FIG. 5, when the photosensitive member 1 and the intermediate transfer member 5 are positioned by contact, the bottom surface of the process cartridge 10Y contacts the top surface of the positioning plate 26Y. Thereby, the vertical play of the process cartridge 10Y can be suppressed, and the positional accuracy of the photosensitive member 1 when contacting the intermediate transfer member 5 can be further improved.

  Further, since the play can be suppressed by contacting each process cartridge with the positioning plate, it is possible to prevent problems such as banding caused by the vibration of the process cartridge.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

  In the above embodiment, the process cartridge is held by the spring, but may be held by an elastic member other than the spring. For example, rubber or leaf spring.

  In the above-described embodiment, the process cartridge is held by the spring. However, the process cartridge is not limited to such a configuration, and the photosensitive member is held by an elastic member such as a spring when the photosensitive member comes into contact with the intermediate transfer member. Good. For example, the photosensitive member may be directly held by an elastic member.

1 is an explanatory diagram showing an outline of an image forming apparatus according to the present invention. FIG. 3 is a diagram showing a configuration around a process cartridge. FIG. 5 is a diagram showing a configuration around a process cartridge when it is positioned. FIG. 6 is a diagram illustrating a configuration around a process cartridge according to a second embodiment. FIG. 6 is a diagram illustrating a peripheral configuration of a process cartridge according to a second embodiment when positioned.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 5 Intermediate transfer body 6 Transfer charger 7 Drive roll 8 Support roll 9 Transfer opposing roll 10Y, 10M, 10C, 10K Process cartridge 101Y Storage part 102Y Bottom part 11 Secondary transfer roll 12 Sheet tray 13 Conveying path 14 Fixing device 15 Discharge tray 16 Cleaning device 20 Holding member 201 Slide groove 202 Engagement pin 21Y Guide 22Y Support surface 23Y First recess 231Y, 241Y Spring 232Y Roller 24Y Second recess 242Y Pressing member 25Y Side wall 26Y Positioning plate 30 Cam member 301 Cam shaft 40 Positioning member 401 Positioning portion

Claims (5)

A process cartridge having a photoconductor, a positioning portion for positioning the photoconductor when the photoconductor comes into contact with the intermediate transfer body, and a holding member for holding the process cartridge in contact with and away from the intermediate transfer body. In an image forming apparatus having
An image forming apparatus comprising: an elastic member that holds the process cartridge away from the holding member when the photosensitive member is positioned by the positioning portion. The process cartridge has a developing device for developing a toner image on the photoconductor,
The image forming apparatus according to claim 1, wherein the holding member holds the process cartridge detachably with respect to the image forming apparatus by separating the photosensitive member from the intermediate transfer member. The image forming apparatus according to claim 1, further comprising: a positioning plate that contacts the process cartridge and positions the photoconductor when the photoconductor is positioned by the positioning unit. The image forming apparatus according to claim 1, wherein the holding member holds a plurality of the process cartridges. 5. The image forming apparatus according to claim 1, wherein the plurality of process cartridges are arranged to be inclined with respect to a horizontal direction.

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