JP6921545B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus of a type in an image forming apparatus such as a copier, a printer, a facsimile, etc., in which a cover of an exterior portion is opened and closed, and a process cartridge mounted inside the apparatus is attached / detached / replaced.

By configuring the image carrier (photosensitive drum) on which the toner image is formed and the image forming device (development roller) as a cartridge that can be attached to and detached from the image forming device main body (device main body), consumables can be replaced. There is a configuration that can be easily maintained.

In this cartridge, there is a contact development method in which a photosensitive drum and a developing roller are brought into contact with each other to develop an image at the time of image formation. In order to hold the photosensitive drum and the developing roller in contact with each other, in Patent Document 1, the developing roller hits the photosensitive drum by an elastic member provided between the developing unit provided with the developing roller of the cartridge and the drum unit provided with the photosensitive drum. I am urging to touch. When the developing roller is separated from the photosensitive drum, the cartridge is pressed by a pressing member provided on the main body of the apparatus to move the developing roller away from the photosensitive drum and maintain that state.

JP-A-2007-21305

However, in a configuration in which the developing roller is urged so as to come into contact with the photosensitive drum by an elastic member provided in the cartridge as in Patent Document 1, it is necessary to provide an elastic member in the cartridge to generate an urging force. The cartridge becomes large. Further, when the cartridge is not attached to the main body of the apparatus, the elastic member urges the developing roller to come into contact with the photosensitive drum. Therefore, if this state is prolonged, the frame of the cartridge, the developing roller, and the photosensitive drum are deformed. There is a risk of doing. Therefore, it is necessary to take measures such as providing a member for suppressing deformation when the cartridge is not attached to the main body of the apparatus.

Further, when the developing unit and the drum unit are configured as separate cartridges so that they can be detached from the main body of the apparatus separately, it is difficult to provide an elastic member between the developing unit and the drum unit in the first place.

Therefore, the present invention further develops the above technique. That is, even if the cartridge does not have an elastic member for bringing the developing member (developing roller) into contact with the photoconductor (photosensitive drum), the developing member is brought into contact with the photoconductor and the developing member is brought into contact with the photoconductor. It is an object of the present invention to provide a configuration capable of being separated from.

Therefore, in the present invention, the first pressing that separates the developing member from the photoconductor by pressing the mounting portion on which the cartridge containing the developing member is mounted by moving in the insertion direction and the cartridge mounted on the mounting portion. In an image forming apparatus having a pressing member including a portion, the pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion. , said and said second pressing portion first pressing portion moves integrally with the movement of the pressing member, the elastic member and the second pressing portion presses the pressing member to press the cartridge The pressing member is provided at a first position where the developing member is separated from the photoconductor by pressing the cartridge with the first pressing portion, and by pressing the cartridge with the second pressing portion. The developing member moves between the second position where the developing member is brought into contact with the photoconductor, and the pressing member rotates about an axis intersecting the insertion direction to bring the developing member into the first position and the second position. It is characterized by moving between.

Further, the present invention includes a mounting portion on which a cartridge including a developing member can be mounted, and a pressing member including a first pressing portion that separates the developing member from the photoconductor by pressing the cartridge mounted on the mounting portion. In the image forming apparatus having the above, the pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion, and the first pressing portion. And the second pressing portion integrally move with the movement of the pressing member, and the pressing member moves the cartridge in the insertion direction and inserts the cartridge into the mounting portion while the cartridge is inserted. A regulating portion for restricting movement in a direction orthogonal to the insertion direction is provided, and the pressing member has a first position for separating the developing member from the photoconductor by pressing the cartridge with the first pressing portion. By pressing the cartridge with the second pressing portion, the developing member moves between the second position where the developing member is brought into contact with the photoconductor, and the pressing member rotates about an axis intersecting the insertion direction. This is characterized by moving between the first position and the second position.
Further, the present invention includes a mounting portion on which a cartridge including a developing member can be mounted, and a pressing member including a first pressing portion that separates the developing member from the photoconductor by pressing the cartridge mounted on the mounting portion. In the image forming apparatus having the above, the pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion, and the first pressing portion. And the second pressing portion integrally move with the movement of the pressing member, and the pressing member moves the cartridge in the insertion direction and inserts the cartridge into the mounting portion while the cartridge is inserted. A regulating unit that regulates movement in a direction orthogonal to the insertion direction is provided, and the regulating unit includes a regulating surface that is different from the first pressing portion and the second pressing portion.

As described above, according to the present invention, even if the cartridge does not have an elastic member for bringing the developing member into contact with the photoconductor, the developing member is brought into contact with the photoconductor and the developing member is exposed to light. It can be made possible to separate from the body.

Schematic cross-sectional view of the image forming apparatus External perspective view of the image forming apparatus with the front door closed External perspective view of the image forming apparatus showing the front door opened and the first cartridge pulled out halfway. External perspective view of the process cartridge as seen from the non-driving side The figure explaining the guide member of a cartridge FIG. 5 is a cross-sectional view taken along the line AA of FIG. 5, showing a guide configuration of a developing unit. The figure explaining the whole structure of the positioning mechanism of a cartridge P The figure explaining the positioning state and the non-positioning state of a cartridge. The figure which showed the whole structure of the contact separation mechanism of a main body The figure which showed the operation of the contact separation mechanism of a main body The figure which showed the details of the pressing member The figure which showed the process which the cartridge P changes from the separated state to the contact state. The figure which showed the process which the contact separation mechanism of a main body changes from the separation state to the contact state. The figure which showed the relationship between the separation lever 53 and the separation cam 54 when changing from the separation state to the contact state. The figure which showed the process which the process cartridge changes from the contact state to the separated state. The figure which showed the process which the contact separation mechanism of a main body changes from the contact state to the separation state. The figure which showed the relationship between the separation lever 53 and the separation cam 54 when changing from the contact state to the separation state. (A) Schematic cross-sectional view of the first cartridge P1, (b) Schematic cross-sectional view of the second cartridge P2.

<Overall schematic configuration of the image forming apparatus>
FIG. 1 is a schematic vertical sectional front view of the image forming apparatus 1 of this embodiment. FIG. 2 is an external perspective view of the image forming apparatus 1 in which the front door (exterior cover) 2 is closed. FIG. 3 is an external perspective view of the image forming apparatus 1 showing a place where the front door 2 is opened and the first process cartridge PY is pulled out halfway.

The image forming apparatus 1 is a four-color full-color laser beam printer using an electrophotographic process, and forms a color image on a recording medium. Further, in the image forming apparatus 1, the first to fourth four process cartridges (hereinafter referred to as cartridges) P (PY, PM, PC, PK) are detachably attached to the image forming apparatus main body 1A. It is a cartridge attachment / detachment method to be used.

Here, with respect to the image forming apparatus 1 of the embodiment, the front side or the front side is the side on which the front door 2 is arranged. The back side or the back side is the opposite side. The front-rear direction is a direction from the back side to the front side (front direction) and the opposite direction (rear direction). The left and right are left or right when the image forming apparatus 1 is viewed from the front side. The left-right direction is a direction from right to left (left direction) and vice versa (right direction). Further, the image forming apparatus main body (hereinafter referred to as the apparatus main body) 1A is an image forming apparatus portion other than the cartridge. Further, in the description of the present embodiment, the longitudinal LD of the cartridge P is parallel to the rotation axis direction (axis direction) of the electrophotographic photosensitive drum (hereinafter referred to as a drum) 3 which is a photoconductor (image carrier). The direction. Further, in the cartridge P, in the longitudinal direction LD, the side where the drive is transmitted from the device main body 1A side (the side where the portion receiving the driving force from the device main body 1A is arranged) is referred to as the drive side, and the opposite side is referred to as the drive side. Called the non-driving side.

A cartridge storage unit 1B for storing each cartridge P is provided in the central portion of the apparatus main body 1A. The storage portion 1B is also a mounting portion into which each cartridge P can be inserted and mounted.

Each cartridge P has the same electrophotographic process mechanism as each other, and the color of the developing agent (hereinafter referred to as toner) and the filling amount of the toner are different from each other. Rotational driving force is transmitted from the apparatus main body 1A side to each cartridge P mounted at a position where an image can be formed in the storage portion 1B, and bias (charging bias, development bias, etc.) is supplied (not shown). ).

In each cartridge P of this embodiment, a drum 3 and a charging means 4, a developing means 5, and a cleaning means 6 as process means acting on the drum 3 are integrally assembled in the cartridge frame 40. A charging roller is used as the charging means 4. As the developing means 5, a developing roller 45, which is a developing member, is used. The rotation axis direction (axis direction) of the developing roller 45 is parallel to the axis direction of the drum 3 in a state where the cartridge P is mounted on the apparatus main body 1A and is positioned. A cleaning blade is used as the cleaning means 6. Below each cartridge P, a laser scanner 8 as an image information exposure means for the drum 3 of each cartridge P is arranged.

Further, a feeding unit 9 is arranged below the laser scanner 8. The feeding unit 9 has a paper cassette 10, a paper feed roller 11, a separation unit 12, a resist roller pair 13, and the like in which a recording material (transfer material: final recording medium) S is loaded and accommodated.

An intermediate transfer unit 14 is arranged above each cartridge P. In this unit 14, the toner image formed on the drum 3 of each of the first to fourth cartridges P (PY, PM, PC, PK) is an intermediate transfer belt (first recording medium: hereinafter referred to as a transfer belt). It is a transfer means that superimposes on 15 and performs primary transfer. The unit 14 has two parallel drive rollers 16 and tension rollers 17 arranged on the right side and the left side, and a flexible endless transfer belt 15 is hung between the two rollers 16 and 17. Being supported. The transfer belt 15 is arranged so as to be oblique with respect to the horizontal direction.

The upper surface of the drum 3 of each cartridge P mounted at a position where an image can be formed in the storage portion 1B is in contact with the lower surface of the belt portion on the descending side of the transfer belt 15. The contact part is the primary transfer part. Inside the transfer belt 15, a primary transfer roller 18 facing each drum 3 is arranged. The transfer belt 15 is driven by the drive roller 16 in the direction of arrow V3 at a speed corresponding to the rotation speed of the drum 3 in a state where the belt portion on the descending side faces and contacts the upper surfaces of all the drums 3. Will be done. A predetermined primary transfer voltage is applied to the primary transfer roller 18 at a predetermined control timing. Further, the secondary transfer roller 19 is in contact with the drive roller 16 via the transfer belt 15. The contact portion between the secondary transfer roller 19 and the transfer belt 15 is the secondary transfer portion. A predetermined secondary transfer voltage is applied to the secondary transfer roller 19 at a predetermined control timing.

A fixing unit 20 and a paper ejection unit 21 are arranged on the upper right side of the apparatus main body 1A. The upper surface of the apparatus main body 1A is a paper ejection tray 22.

The cartridges PY, PM, PC, and PK are mounted side by side in the arrangement direction AD. At this time, the rotation axis of the drum 3 of each cartridge P is arranged on the straight line shown by the alternate long and short dash line in FIG.

<Cartridge configuration>
FIG. 4 is an external perspective view of one Cartlitz Ji P as viewed from the non-driving side. The cartridge P is an assembly whose longitudinal direction is the axial direction of the drum 3. The cartridge frame 40 includes a cleaning unit 43 and a developing unit 44. The drum 3 has a first bearing member (non-driving side) 41 and a second bearing member (driving side) in which one end side and the other end side of the longitudinal LD are arranged on one end side and the other end side of the cleaning unit 43. It is rotatably supported and arranged between it and 42. The developing roller 45 is rotatably supported by the developing unit 44. A developing container for accommodating toner is provided in the developing unit 44. In the longitudinal direction LD of the upper part of the cleaning unit 43, the cartridge upper rib 43A is provided on the back side, and the cartridge lower rib 43B is provided on the lower part of the cleaning unit 43.

In the first cartridge PY, yellow (Y) toner is contained in the developing container, and a Y-color toner image is formed on the surface of the drum 3. The second cartridge PM contains magenta (M) toner in a developing container and forms an M-color toner image on the surface of the drum 3. In the third cartridge PC, cyan (C) toner is contained in the developing container, and a C-color toner image is formed on the surface of the drum 3. The fourth cartridge PK contains black (K) toner in the developing container and forms a K-color toner image on the surface of the drum 3.

<Cartridge replacement method and attachment / detachment method>
In the image forming apparatus of this embodiment, each cartridge P is replaced by opening the front door 2 which is an opening / closing member of the apparatus main body 1A as shown in FIG. 3 and performing front access. Reference numeral 2a is a handle portion arranged on the front door 2. The paper cassette 10 is also taken in and out by front access.

In the front plate 38 of the device main body 1A, an opening 24 (to attach / detach the cartridge) through which the cartridge P is passed in order to insert the cartridge P into the device main body 1A and take out the cartridge P from the device main body 1A is taken out. (Opening) is provided. The attachment / detachment direction of the cartridge P with respect to the apparatus main body 1A is the axial direction of the drum 3.

The front side plate 38 of the apparatus main body 1A is provided with a front door 2 as an opening / closing member that can move between a closing position that covers and closes the opening 24 and an opening position that opens the opening 24. There is. Further, a cartridge door 23 is provided between the front door and the front side plate to facilitate the mountability of the cartridge. The cartridge door 23 opens and closes in conjunction with the front door.

In this embodiment, the front door 2 opens the opening 24 around the horizontal door rotation shaft (first rotation shaft) 25 (see FIG. 2) arranged on the lower side thereof. A state and a closed state in which the opening 24 is closed can be taken. The door rotating shaft 25 is rotatably supported by a bearing member 26 provided on the front plate 38 of the apparatus main body 1A. In this embodiment, the door rotation shaft 25 is arranged so that its axis direction is left-right and horizontal in consideration of the user's door operability. The front door 2 is closed so that its surface 2S covers the front side plate 38 of the apparatus main body 1A, and the front side plate 38 uses the door rotation shaft 25 as a fulcrum from a rotation angle posture in which the surface 2S is substantially parallel in the vertical direction. The surface 2S can be rotated approximately 90 ° to the front side of the door to form a rotation angle posture in which the surface 2S is opened substantially horizontally.

Next, a cartridge attachment / detachment method will be described with reference to FIGS. 3, 5 and 6. FIG. 5 is a view for explaining each of the cartridge guide members, and is a view seen from the axial direction of the drum 3. FIG. 6 is a cross-sectional view taken along the line AA of FIG. The cross section (dashed line) shown by AA in FIG. 5 is parallel to the arrangement direction AD of the cartridge P.

A cartridge upper guide 30 and a cartridge lower guide 31 that guide the first to fourth cartridges P (PY, PM, PC, PK) at the time of attachment / detachment to the cartridge storage portion 1B (inside the image forming apparatus main body) of the apparatus main body 1A. And the development guide 32 is arranged.

When the cartridge P is inserted into the storage portion 1B, the cartridge upper rib 43A and the cartridge lower rib 43B are inserted so as to be sandwiched between the cartridge upper guide 30 and the cartridge lower guide 31 arranged on the main body side, respectively. The insertion direction ID, which is the moving direction of the cartridge P when the cartridge P is inserted into the storage portion 1B, is parallel to the longitudinal direction LD of the cartridge P mounted on the apparatus main body 1A. Further, the developing unit 44 has a structure that can rotate around the developing rotation center 43C, but the developing unit 44 is inserted while the pressed portion 44A is regulated by the developing guide 32. By the regulation by the development guide 32, the development unit 44 is restricted from moving in the direction orthogonal to the insertion direction ID. In the present embodiment, the direction orthogonal to the insertion direction ID is the arrangement direction AD. When the cartridge P is completely inserted into the storage portion 1B, the cartridge upper rib 43A and the cartridge lower rib 43B are held by a holding portion (not shown) of the apparatus main body 1A.

FIG. 6 shows a cross section taken along the line AA in FIG. 5, showing a state in which the cartridge P is being inserted. The development unit 44 is regulated by the development guide 32 at the initial stage of insertion. After passing through the development guide 32, it is regulated by the pressing members 50 arranged at two places with respect to the insertion direction ID, and is inserted to a predetermined position. The pressing member 50 is provided with a development restricting surface 50C, a first pressing surface (first pressing portion) 50B, and a second pressing surface (second pressing portion) 50A. The development restricting surface 50C, the second pressing surface 50A, and the first pressing surface 50B are arranged so as to face each other with respect to the arrangement direction AD via the pressed portion 44A of the developing unit 44. The development restricting surface 50C, the second pressing surface 50A, and the first pressing surface 50B restrict the movement of the pressed portion 44A of the cartridge P being inserted into the storage portion 1B in the arrangement direction AD. That is, the development restricting surface 50C, the second pressing surface 50A, and the first pressing surface 50B are regulation units that restrict movement in a direction orthogonal to the insertion direction ID of the cartridge P (arrangement direction AD in this embodiment). be. That is, the second pressing surface 50A and the first pressing surface 50B form at least a part of the regulation unit that regulates the movement in the direction orthogonal to the insertion direction ID of the cartridge P. As is clear from FIG. 11, since the pressing member 50 is one member formed of resin, the first pressing surface 50B and the second pressing surface 50A are integrated with the movement of the pressing member 50. It is a configuration that moves to.

Further, since the pressing member 50 operates in conjunction with the developing unit 44 on the main stay 33 during the contact separation operation of the cartridge P, it does not interfere with the contact separation operation. When the cartridge P is completely inserted into the storage portion 1B, the pressed portion 44A and the development guide 32 are located at different positions depending on the insertion direction ID, so that the contact separation operation of the cartridge P, which will be described later, is not hindered.

<Positioning operation of process cartridge to the main body>
Next, the positioning operation after the cartridge P has been completely inserted into the main body will be described. FIG. 7 is a diagram illustrating the overall configuration of the positioning mechanism of the process cartridge P.

As described above, the cartridge door 23 is configured to rotate around the axis of the rail shaft 34 in conjunction with the front door 2 (see FIG. 3). The rail shaft 34 is connected to the cartridge door 23 via a link lever 35, and rotates in conjunction with the operation of the cartridge door 23. Further, the cartridge lower guide 31 is attached to the rail shaft 34 via the front rail arm 36. The cartridge lower guide 31 is also connected to the rear rail arm 37, which rotates in the same phase as the front rail arm 36. Therefore, the cartridge lower guide 31 can move in the positioning direction PD in conjunction with the front door 2. The positioning direction PD is a direction orthogonal to the arrangement direction AD and the insertion direction ID. FIG. 8 is a diagram showing a positioned state and a non-positioned state of the cartridge P, and is a view seen from the axial direction of the drum 3. The solid line in FIG. 8 shows the state in which the cartridge P is positioned with respect to the main body, and the broken line indicates the non-positioning state in which the cartridge P is not positioned with respect to the device main body 1A although the insertion into the storage portion 1B is completed. Indicates the state.

When the user closes the front door 2 after the cartridge P is installed in the main body, the cartridge lower guide 31 moves (rises) in the positioning direction PD in conjunction with the closing operation of the front door 2. The front pressure piece 57 and the rear pressure piece 58 (see FIG. 7) are attached to the cartridge lower guide 31 at two different places with respect to the insertion direction ID. The cartridge P is pressurized upward by the pressure pieces 57 and 58 on the front side and the rear side, and abutted against each of the positioning portion 38a of the front side plate 38 and the positioning portion 39a of the rear side plate 39 (not shown), and the cartridge P is pressed. Positioning.

<Abutment separation mechanism and operation of the main body>
Next, the contact separation mechanism provided on the apparatus main body 1A will be described with reference to FIGS. 9 to 11. FIG. 9 is an exploded perspective view showing the overall configuration of the contact separation mechanism of the main body, and FIG. 10 is a view of the contact separation mechanism viewed from the opposite direction of the positioning direction PD. Further, FIG. 11 is a perspective view showing the details of the pressing member 50.

The contact separation mechanism is mainly composed of a pressing member 50, a slide member 51, a developing pressure spring 52, a separation lever 53, and a separation cam 54, and is provided one by one corresponding to each cartridge P. Therefore, in the following description, one contact separation mechanism corresponding to one cartridge P will be described, and the other contact separation mechanism corresponding to the other cartridge P has the same configuration, and thus the description thereof will be omitted. Further, in FIG. 9, for the sake of simplicity, only the contact separation mechanism corresponding to the cartridge Pk is shown, and the description of the other contact separation mechanism is omitted.

As shown in FIG. 9, the pressing members 50 are rotatably attached to the main stay 33 at two locations arranged in the insertion direction around the rotary boss 50E. When the pressing member 50 rotates about the rotation boss 50E, the rotation axis on which the pressing member 50 rotates is parallel to the positioning direction PD. That is, the rotation axis intersects (including orthogonality) with the insertion direction ID. The slide member 51 is attached on the main stay 33 via the developing guide 32 and the slide bearing 55, and can slide only in the insertion direction ID. Further, the separation lever 53 is a member that connects the separation cam 54 and the slide member 51, and can rotate around the rotation boss 53A on the main stay 33. The rotation axis of the separation lever 53 is parallel to the positioning direction PD. A developing pressure spring (elastic member) 52 is attached to the hook portion 50D of the pressing member 50 and the spring seat 33A on the main stay 33.

The contact separation mechanism takes a contact position for bringing the cartridge P into a contact state and a separation position for bringing the cartridge P into a distance state. FIG. 10B shows a state in which the contact separation mechanism is in the contact position, and the development pressure spring 52 causes the second pressing surface (second pressing portion) 50A of the pressing member 50 to be the developing unit 44. 44A (see FIG. 8) to be pressed can be pressed in the direction of arrow F1. FIG. 10A shows a state in which the contact separation mechanism is in the separation position, and the first pressing surface 50B of the pressing member 50 makes the pressed portion 44A of the developing unit 44 an arrow opposite to the arrow F1 direction. It is in a state where it can be pressed in the F2 direction.

<Cartridge contact separation operation>
Next, the contact separation operation of the cartridge P will be described in detail with reference to FIGS. 12 to 17.

First, the operation of displacing the process cartridge P from the separated state to the contacted state will be described with reference to FIGS. 12 to 14. The separated state is a state in which the developing roller 45 is separated from the drum 3 by a predetermined distance or more, and the contact state is a state in which the developing roller 45 is in contact with the drum 3 and is pressurized. The intermediate state is a state in which the developing roller 45 is separated from the drum 3 by a distance of less than a predetermined distance, which is a state in which the transition between the abutting state and the separating state is performed. When in the abutting state, the toner supported on the surface of the developing roller 45 can be attached to the surface of the drum 3, and the latent image formed on the drum 3 can be developed with the toner.

FIG. 12 is a diagram showing the process in which the cartridge P changes from the separated state to the contacted state, and is a view seen by the insertion direction ID, in which (a) is the separated state, (b) is the intermediate state, and (c). ) Indicates the contact state. FIG. 13 is a diagram showing a process in which the contact separation mechanism of the main body changes from the separation state to the contact state, and is a view seen in the opposite direction of the positioning direction PD. FIG. ) Indicates an intermediate state, and (c) indicates a contact state. Further, FIG. 14 is a view of the separation lever 53 and the separation cam 54 when changing from the separation state to the contact state in terms of the insertion direction ID, where (a) is the separation state and (b) is the intermediate state. (C) shows the contact state.

In the separated state shown in FIGS. 12 (a), 13 (a), and 14 (a), the pressing member 50 is always urged in the direction of arrow W1 by the pressing force of the developing pressure spring 52. Further, the bent portion 51A of the slide member 51 receives the pressing force of the developing pressurizing spring 52 from the hooking portion 50D of the pressing member 50, and is always urged in the direction of arrow V1. Similarly, the separation lever 53 that engages with the slide member 51 is always urged in the direction of arrow Q1, and the arm portion 53A of the separation lever 53 is always urged in the direction of arrow T1 shown in FIG. It abuts on the outer peripheral surface (cam surface) 54A of 54. When the arm portion 53A abuts on the outer peripheral surface 54A and the position of the separation lever 53 is determined, the positions of the slide member 51 and the pressing member 50 are also determined.

When the separation motor (not shown) is driven from the separation state, the separation cam 54 starts rotating in the direction of arrow R1 as shown in FIG. 14 (b). When the rotation of the separation cam 54 starts, the arm 53A moves in the T1 direction while sliding on the outer peripheral surface 54A of the separation cam 54 due to the pressing force of the developing pressure spring 52, and the separation lever 53 moves on the main stay as an arrow. It rotates in the Q1 direction, and the slide member 51 slides in the arrow V1 direction. At the same time, the pressing member 50 rotates on the main stay 33 in the direction of the arrow W1. Then, as shown in FIG. 12B, the second pressing surface 50A presses the pressed portion 44A of the developing unit 44, and the developing unit 44 rotates about the rotation center 43C in the direction of the arrow Y1. When the separation cam 54 further rotates in the direction of arrow R1 from this state, the developing roller 45 presses the developing pressure spring 52 transmitted through the second pressing surface 50A, as shown in FIG. 12 (c). The contact state is such that the drum 3 is in contact with the drum 3 at a predetermined contact pressure. In the contact state, as shown in FIG. 14C, there is a predetermined gap between the separation cam 54 and the separation lever 53 in the contact state. With this configuration, the pressing force of the developing pressure spring 52 can be converted into a force for pressing the developing roller 45 on the drum 3 with a small loss.

Next, the operation of displacing from the contact state to the separated state will be described with reference to FIGS. 15 to 17. 15A and 15B are views of the insertion direction ID showing the process in which the cartridge P changes from the contact state to the separated state. FIG. 15A is a contact state, FIG. 15B is an intermediate state, and FIG. 15C is an intermediate state. Indicates a separated state. 16A and 16B are views in the direction opposite to the positioning direction PD showing the process in which the contact separation mechanism of the main body changes from the contact state to the separation state. FIG. The intermediate state and (c) indicate the separated state. Further, FIG. 17 is a view of the separation lever 53 and the separation cam 54 when changing from the contact state to the separation state in terms of the insertion direction ID, where (a) is the contact state and (b) is the intermediate state. , (C) indicate the separated state.

When the separation motor (not shown) is driven from the contact state shown in FIGS. 15 (a), 16 (a), and 17 (a), the separation cam 54 is indicated by the arrow R2 as shown in FIG. 17 (b). Start rotating in the direction. When the separation cam 54 starts to rotate, the arm portion 53A of the separation lever 53 slides on the slope 54A of the separation cam 54, whereby the separation lever 53 slides on the main stay 33 as shown in FIG. 16B. Start rotating in the direction of arrow Q2. Therefore, the slide member 51 is pressed by the separation lever 53 and slides in the direction of arrow V2. As a result, as shown in FIG. 15B, the pressing member 50 is pressed by the slide member 51 and begins to rotate on the main stay 33 in the direction of arrow W2 against the urging force of the developing pressure spring 52. As a result, the first pressing surface 50B of the pressing member 50 presses the pressed portion 44A of the developing unit 44, and the developing unit 44 rotates about the rotation center 43C in the arrow Y2 direction. When the separation cam 54 further rotates from this state, as shown in FIG. 17C, the arm portion 53A of the separation lever 53 slides to the outermost diameter surface 54B of the outer peripheral surface 54A of the separation cam 54 and develops. The roller 45 is separated from the drum 3 by a predetermined distance, and the separation from the drum 3 is completed (state of FIG. 15C).

As shown in the above description and FIGS. 12 and 15, the arrow Y1 direction and the arrow Y2 direction, which are the directions in which the developing unit 44 moves between the contact state and the separated state, are directions that intersect with the insertion direction ID. Is.

In this embodiment, two pressing members 50 are arranged so as to line up in the insertion direction ID for one cartridge P, and two pressing members 50 are connected to one slide member 51. Of course, three or more pressing members 50 may be arranged for one cartridge P. Further, as long as the uniformity such as the contact pressure and the separation amount is less likely to be uneven over the longitudinal direction of the pressing member 50 developing roller 45, only one pressing member 50 may be provided for one cartridge P. .. Further, even when two pressing members 50 are provided, two slide members 51 corresponding to the two pressing members 50 may be provided instead of moving the two pressing members 50 by one slide member 51.

Further, in this embodiment, the cartridge P is for integrally attaching and detaching the cleaning unit 43 and the developing unit 44 from the apparatus main body 1A. However, the configuration of the cartridge P is not limited to this. That is, the cartridge configuration may be such that only the developing unit 44 can be removed from the device main body 1A without removing the cleaning unit 43 from the device main body 1A. For example, the developing unit 44 may be the first cartridge P1, the cleaning unit 43 may be the second cartridge P2, or the like, and the first cartridge P1 and the second cartridge P2 may be individually attached to and detached from the apparatus main body 1A.

FIG. 18A is a schematic cross-sectional view of the first cartridge P1 and is a view seen from the direction of the rotation axis of the developing roller 45. FIG. 18B is a schematic cross-sectional view of the second cartridge P2 and is a view seen from the direction of the rotation axis of the drum 3. The parts having the same functions as those in the above-described embodiment are designated by the same reference numerals. The first cartridge P1 is mounted on the apparatus main body 1A, and the first cartridge P1 is rotatably held around the development rotation center 43C in a holding portion (not shown) of the apparatus main body 1A. In the second cartridge P2, the upper rib 43A of the cartridge and the lower rib 43B of the cartridge are each held by a holding portion (not shown) of the apparatus main body 1A.

According to this embodiment, the pressing member 50 can press the cartridge P so that the developing roller 45 abuts on the drum 3 with a predetermined pressure while pressing the cartridge P so as to separate the developing roller 45 from the drum 3. .. Therefore, even if the cartridge does not have an elastic member for bringing the developing roller 45 into contact with the drum 3, the developing roller 45 can be brought into contact with the drum 3 and separated from the drum 3. .. Of course, it can also be applied to a configuration in which the cartridge has an elastic member for bringing the developing roller 45 into contact with the drum 3. In this case, since the pressing force by the pressing member 50 can be obtained when the developing roller 45 is brought into contact with the drum 3, the urging force of the elastic member is increased as compared with the configuration in which the developing roller 45 is brought into contact with the drum 3 only by the elastic member. It can be weakened. As described above, since the urging force may be weak, it becomes possible to use an elastic member smaller than the conventional one or an inexpensive elastic member accordingly.

Further, when the developing unit 44 is inserted, the pressing member 50 can restrict the movement in the direction orthogonal to the insertion direction ID of the developing unit 44 to guide the insertion. Therefore, the number of regulation members (guide members) dedicated to regulation (guide) can be reduced as much as possible, and the cost and size of the image forming apparatus can be reduced. In particular, in the case of a configuration in which the cleaning unit 43 and the developing unit 44 can be individually removed from the apparatus main body 1A, it is necessary to regulate the cleaning unit 43 and the developing unit 44, respectively, which is more effective in reducing the cost and downsizing of the image forming apparatus. ..

1 Image forming device 1A Image forming device body 1B Cartridge storage part 3 Drum 5 Developing means 40 Cartridge frame 43 Cleaning unit 43C Development rotation center 44 Cleaning unit 44A Pressed part 45 Development roller 50 Pressing member 50A Second pressing surface 50B No. One pressing surface 50C Control surface 51 Slide member 52 Developing pressure spring 53 Separation lever 54 Separation cam P (PY / PM / PC / PK) Process cartridge

Claims (11)

A pressing member including a mounting portion on which a cartridge containing a developing member is mounted by moving in an insertion direction, and a first pressing portion that separates the developing member from a photoconductor by pressing the cartridge mounted on the mounting portion. In an image forming apparatus having
The pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion, and the first pressing portion and the second pressing portion are As the pressing member moves, it moves integrally and
An elastic member that presses the pressing member so that the second pressing portion presses the cartridge is provided.
The pressing member presses the cartridge with the first pressing portion to separate the developing member from the photoconductor, and presses the cartridge with the second pressing portion to press the developing member. Move between the second position to be brought into contact with the photoconductor,
An image forming apparatus, characterized in that the pressing member moves between the first position and the second position by rotating around an axis intersecting the insertion direction. The pressing member is characterized by comprising a regulating portion that restricts the movement of the cartridge in a direction orthogonal to the inserting direction while the cartridge is moved in the insertion direction and inserted into the mounting portion. The image forming apparatus according to 1. Image formation having a mounting portion on which a cartridge including a developing member can be mounted and a pressing member including a first pressing portion that separates the developing member from the photoconductor by pressing the cartridge mounted on the mounting portion. In the device
The pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion, and the first pressing portion and the second pressing portion are As the pressing member moves, it moves integrally and
The pressing member includes a regulating portion that restricts the movement of the cartridge in a direction orthogonal to the inserting direction while the cartridge is moved in the insertion direction and inserted into the mounting portion .
The pressing member presses the cartridge with the first pressing portion to separate the developing member from the photoconductor, and presses the cartridge with the second pressing portion to press the developing member. Move between the second position to be brought into contact with the photoconductor,
An image forming apparatus, characterized in that the pressing member moves between the first position and the second position by rotating around an axis intersecting the insertion direction. The image forming apparatus according to claim 2 or 3, wherein the first pressing portion constitutes at least a part of the regulating portion. The image forming apparatus according to any one of claims 2 to 4, wherein the second pressing portion constitutes at least a part of the regulating portion. The image forming apparatus according to any one of claims 2 to 5, wherein the regulating portion includes a regulating surface different from that of the first pressing portion and the second pressing portion. The image forming apparatus according to any one of claims 1 to 6, wherein the insertion direction is a direction along the longitudinal direction of the developing member. Claims 1 to 7 are characterized in that the insertion direction is a direction intersecting a moving direction in which the cartridge moves between a position where the developing member is separated from the photoconductor and a position where the developing member is in contact with the developing member. The image forming apparatus according to any one of the above. Another first pressing portion that separates the developing member from the photoconductor by pressing the cartridge mounted on the mounting portion, and the developing member by pressing the cartridge mounted on the mounting portion. It has another pressing member including another second pressing portion that comes into contact with the photoconductor.
The image forming apparatus according to any one of claims 1 to 8, wherein the pressing member and the other pressing member are arranged side by side in the insertion direction. The image forming apparatus according to any one of claims 1 to 9 , wherein a cartridge different from the cartridge provided with the photoconductor can be mounted on the mounting portion. Image formation having a mounting portion on which a cartridge including a developing member can be mounted and a pressing member including a first pressing portion that separates the developing member from the photoconductor by pressing the cartridge mounted on the mounting portion. In the device
The pressing member includes a second pressing portion that brings the developing member into contact with the photoconductor by pressing the cartridge mounted on the mounting portion, and the first pressing portion and the second pressing portion are As the pressing member moves, it moves integrally and
The pressing member includes a regulating portion that restricts the movement of the cartridge in a direction orthogonal to the inserting direction while the cartridge is moved in the insertion direction and inserted into the mounting portion.
The image forming apparatus is characterized in that the regulating portion includes a regulating surface different from the first pressing portion and the second pressing portion.

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