JP4735768B2 - Image forming apparatus - Google Patents

Description

  The present invention provides an image including a conveyance belt disposed to face a plurality of photosensitive drums, a plurality of process cartridges having the photosensitive drums, and a moving member that holds the plurality of process cartridges and can be pulled out from the apparatus main body. The present invention relates to a forming apparatus.

  In general, there is known an intermediate transfer type image forming apparatus that transfers toner images on a plurality of photosensitive drums to a sheet via an intermediate transfer belt. As such an image forming apparatus, conventionally, a plurality of process cartridges having photosensitive drums, an intermediate transfer belt disposed to face each photosensitive drum, and a plurality of process cartridges are supported and can be pulled out from the apparatus main body. The thing provided with the drawer is known (refer patent document 1). In this technique, each process cartridge can be replaced by pulling out a drawer from the apparatus main body.

JP 2007-213081 A

  By the way, when the structure of the prior art is changed to a direct tandem system in which a toner image is directly transferred from each photosensitive drum to a sheet instead of an intermediate transfer system, a transport belt for transporting a sheet is used instead of the intermediate transfer belt. Since it is necessary to arrange it so as to face the drum, there arises a problem that the paper is jammed between the photosensitive drum and the conveyance belt. In this case, if you remove the drawer from the main unit, you can remove the jammed paper from the drawer outlet. However, if the drawer can be removed, the removed heavy drawer can be removed. Therefore, there is a problem that the work for assembling the apparatus main body becomes necessary and the jam processing becomes complicated. Further, when only one process cartridge is to be replaced, for example, the user must perform the replacement while supporting the drawer so that the drawer does not come off the apparatus main body. there were.

  Accordingly, the present invention provides an image forming apparatus capable of facilitating jam processing and process cartridge replacement work by enabling jam processing without removing a drawer (moving member) from the apparatus main body. With the goal.

  The present invention that solves the above-described problems includes an apparatus main body, a plurality of process cartridges arranged in parallel in one direction, each having a photosensitive drum on which an electrostatic latent image is formed, and the photosensitive drums of the plurality of process cartridges. A conveyance belt that conveys a recording sheet to and from each photosensitive drum, a moving member that holds the plurality of process cartridges and that can be pulled out in the parallel direction of the process cartridges with respect to the apparatus main body, An image forming apparatus including a restriction mechanism for restricting movement of the moving member, wherein the moving member includes a mounting position where each photosensitive drum of the plurality of process cartridges faces the conveyance belt, and the plurality of processes. An exchange position at which all of the cartridges are exposed outside the apparatus main body and can be exchanged, and the parallel direction further than the exchange position The restriction mechanism is configured to be movable between an outer jam processing position and the restriction mechanism includes a first restriction wall provided in the apparatus main body for stopping movement of the moving member at the replacement position, and movement of the moving member. To stop at the jam processing position, a switching lever that is rotatably supported by the moving member, and a switching lever that is provided on the switching lever, thereby providing the first regulating wall. A first contact portion that is movable between a contact position that contacts the first restriction wall and a non-contact position that deviates from the first restriction wall, and a second contact that is provided on the moving member and contacts the second restriction wall. And when a predetermined number of process cartridges located on the most upstream side in the pull-out direction of the moving member among the plurality of process cartridges are mounted on the moving member, the predetermined number of process cartridges Wherein that the switching lever is pressed by the cartridge, wherein said first contact portion is configured to be held in the contact position.

  According to the present invention, when the user pulls out the moving member from the apparatus main body, the moving member is stopped at the replacement position by the restriction mechanism. Therefore, the user can replace the process cartridge at this replacement position without supporting the moving member. Further, when a predetermined number of process cartridges on the most upstream side are removed at the replacement position, the restriction mechanism is activated, and the moving member can move from the replacement position to the jam processing position. Therefore, when the jam processing is performed, the gap between the remaining process cartridges other than the predetermined number formed by removing the predetermined number of process cartridges and the apparatus main body is widened by the movement of the moving member. However, it is possible to easily perform jam processing from a large gap. Further, after removing the recording sheet, it is not necessary to assemble the removed heavy drawer (moving member) to the main body of the apparatus according to the outlet, so that it is possible to facilitate the jam processing.

  According to the present invention, it is possible to perform jam processing and process cartridge replacement work without removing the moving member from the apparatus main body, so that jam processing and process cartridge replacement work can be facilitated.

1 is a cross-sectional view illustrating an overall configuration of a color laser printer as an example of an image forming apparatus according to an embodiment of the present disclosure. It is the perspective view (a) which looked at the drawer from diagonally upward, and the expansion perspective view (b) which looked at X part of Fig.2 (a) from diagonally downward. FIG. 4 is a side view (a) showing a state where the process cartridge is mounted on the drawer, and a side view (b) showing a state where the process cartridge is removed from the drawer. FIG. 4 is a perspective view (a) of the color laser printer with the front panel opened as viewed obliquely from above, and a perspective view (b) of the side panel partially broken away. A perspective view showing a state in which the drawer is pulled out to the replacement position, a perspective view showing the state in which the innermost process cartridge is removed from the drawer, and a state in which the drawer is pulled out from the replacement position to the jam processing position It is a perspective view (c) which shows. FIG. 5B is a cross-sectional view taken along the line YY of FIG. 4B, showing a state in which the first contact portion is in contact with the first restriction wall, and the first contact portion is detached from the first restriction wall. FIG. 6B is a cross-sectional view showing a state where the second contact portion is in contact with the second regulating wall. FIG.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a cross-sectional view showing an overall configuration of a color laser printer as an example of an image forming apparatus according to an embodiment of the present invention. In the following description, the overall configuration of the color laser printer will be described first, and then the details of the features of the present invention will be described.

<Overall configuration of color laser printer>
As shown in FIG. 1, the color laser printer 1 includes a paper feeding unit 3 that supplies a sheet P as an example of a recording sheet in an apparatus main body 2 and an image forming unit 4 that forms an image on the fed paper P. Etc.

  In the following description, unless otherwise specified, the vertical direction shown in FIG. 1 is up and down, the right side in FIG. 1 is front side, the left side is back, the back side of the paper is right, and the front side of the paper is left. Indicates.

<Configuration of paper feed unit>
The paper feed unit 3 includes a paper feed tray 31 that is detachably attached to the apparatus main body 2 and a paper supply mechanism 32 that conveys the paper P in the paper feed tray 31 to the image forming unit 4. In the paper feed unit 3, the paper P in the paper feed tray 31 is conveyed to the image forming unit 4 by rollers and guides (not shown) of the paper supply mechanism 32.

<Configuration of image forming unit>
The image forming unit 4 includes an exposure unit (not shown), a process unit 5, a transfer unit 6, and a fixing unit 7.

  The process unit 5 includes a plurality (four) of process cartridges 51 arranged in parallel in the front-rear direction and a drawer 8 as an example of a moving member that holds the plurality of process cartridges 51.

  The process cartridge 51 includes a photosensitive drum 52 on which an electrostatic latent image is formed, a known charger (not shown), a developing roller, a toner storage chamber, and the like. In the process cartridge 51, the surface of the photosensitive drum 52 charged by the charger is exposed by the exposure unit, whereby an electrostatic latent image based on image data is formed on the surface of the photosensitive drum 52. A toner image is carried on the photosensitive drum 52 by supplying toner to the electrostatic latent image from the developing roller.

  The exposure unit may be a device that emits laser light or a device that includes a plurality of LEDs. Further, the shape of the process cartridge 51 may be changed as appropriate so that the laser light can pass through or a plurality of LEDs can be arranged.

  The drawer 8 is supported by the apparatus main body 2 so as to be movable in the front-rear direction. The drawer 8 can be pulled out by opening a front cover 21 that is rotatably provided on the front side of the apparatus main body 2. Yes. The details of the drawer 8 will be described later.

  The transfer unit 6 includes a driving roller 61, a driven roller 62, a conveyance belt 63, and a transfer roller 64.

  The driving roller 61 and the driven roller 62 are spaced apart and arranged in parallel, and a conveyance belt 63 made of an endless belt is wound around them. The outer surface of the conveyor belt 63 is disposed so as to face each photosensitive drum 52 and is in contact therewith. A transfer roller 64 is disposed inside the conveyor belt 63 so as to sandwich the conveyor belt 63 between the photosensitive drums 52. A transfer bias is applied to the transfer roller 64 from a high-pressure substrate (not shown). At the time of image formation, the sheet P conveyed by the conveying belt 63 is sandwiched between the photosensitive drum 52 and the transfer roller 64 via the conveying belt 63, and the toner image on the photosensitive drum 52 is transferred to the sheet P.

  The fixing unit 7 includes a heating roller 71 and a pressure roller 72. In the fixing unit 7, the toner transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 71 and the pressure roller 72.

<Drawer structure>
Next, the structure of the drawer 8 which is a characteristic part of the present invention will be described. In the drawings to be referred to, FIG. 2 is a perspective view (a) of the drawer viewed from diagonally above, and an enlarged perspective view (b) of X portion of FIG. 2 (a) viewed from diagonally below. FIG. FIG. 4 is a side view (a) showing a state where a process cartridge is mounted, and a side view (b) showing a state where the innermost process cartridge is removed from the drawer.

  As shown in FIG. 2A, the drawer 8 includes a front frame 81, a pair of side frames 82, a rear frame 83, three beam portions 84, and a switching lever 85.

  The front frame 81 is a frame that extends in the left-right direction, and a U-shaped handle portion 81A that protrudes toward the front side is provided at the center in the left-right direction.

  The side frame 82 is a frame that extends in the front-rear direction, and is formed so as to extend from both ends of the front frame 81 toward the back. A flange portion 82A that protrudes outward in the left-right direction and extends in the front-rear direction is formed on the upper portion of the side frame 82, and the outer end in the back side of the flange portion 82A (the distal end portion of the extension portion described later) A second abutting portion 82 </ b> B is formed so as to protrude from the surface. Here, the second contact portion 82 </ b> B constitutes a part of a regulation mechanism that regulates the movement of the drawer 8.

  Further, as shown in FIG. 2B, a shaft portion 82 </ b> C that supports the switching lever 85 in a swingable manner and a side view for restricting the swinging of the switching lever 85 are provided at the lower part of the side frame 82. A substantially V-shaped restriction groove 82D is formed. The regulation groove 82D has an inclined surface 82E that is inclined upward as it goes from the back to the front, and the end of the switching lever 85 in front of the inclined surface 82E comes into contact with the inclined surface 82E so that the switching lever 85 becomes a horizontal surface. It is designed to maintain a tilted posture.

  The rear frame 83 is formed so as to connect the pair of side frames 82 at a position slightly shifted forward from an end on the back side of the side frame 82. The rear frame 83, a portion of the side frame 82 on the front side of the rear frame 83, and the front frame 81 form a square frame that surrounds and supports the plurality of process cartridges 51 together. It has become. Further, a portion of the side frame 82 on the back side of the rear frame 83 is an extending portion that extends to the back side of the frame body.

  The three beam portions 84 are formed so as to connect the pair of side frames 82, respectively, and are arranged at equal intervals between the front frame 81 and the rear frame 83. Each process cartridge 51 is inserted between the beam portion 84, the front frame 81, and the rear frame 83, and each process cartridge 51 is formed in a part of the drawer 8 in the inserted state. By engaging, as shown in FIG. 3A, the drawer 8 is held at a predetermined position.

  The switching lever 85 is a part that constitutes a part of a regulating mechanism that regulates the movement of the drawer 8, and as shown in FIG. 2B, the base 85A, the first abutting portion 85B, the cartridge abutting portion 85C, A spring engaging portion 85D is provided.

  The base portion 85A is a long plate-like member, and is rotatably supported by the shaft portion 82C via a portion (not shown) extending from the substantially central portion toward the shaft portion 82C. Then, the end on the back side of the base portion 85A extends to the back side from the rear frame 83 (frame body).

  The first abutting portion 85B is disposed on the outer side in the left-right direction with respect to the end portion on the far side of the base portion 85A via a connecting portion 85E extending in the left-right direction. As shown in FIG. 3A, the first contact portion 85B is in contact with a first restriction wall A3 (see FIG. 4B) described later when the switching lever 85 is in a horizontal posture. It is located at the contact position where it touches. Further, as shown in FIG. 3B, the first contact portion 85B is located at a non-contact position that is disengaged from the first restriction wall A3 when the switching lever 85 is tilted.

  As shown in FIG. 2B, the cartridge contact portion 85C is formed so as to extend inward in the left-right direction from the side frame 82 from the front end portion of the base portion 85A, and the innermost beam portion 84 is formed. And the rear frame 83 are exposed upward. That is, the cartridge contact portion 85C can contact the process cartridge 51 disposed on the innermost side.

  The spring engaging portion 85D is formed so as to protrude outward in the left-right direction from the position on the cartridge contact portion 85C side of the shaft portion 82C in the base portion 85A. A torsion spring 86 as an example of an urging member attached to the shaft portion 82 </ b> C is disposed between the spring engaging portion 85 </ b> D and the side frame 82. Accordingly, the switching lever 85 is urged by the torsion spring 86 so that the first contact portion 85B is always located at the non-contact position (see FIG. 3B).

  The switching lever 85 configured as described above is provided when the process cartridge 51 on the farthest side (the uppermost stream side in the drawer direction of the drawer 8) is attached to the drawer 8, as shown in FIG. In other words, the cartridge contact portion 85C is pushed down and supported by the process cartridge 51, so that the horizontal posture (contact position) is maintained. Further, as shown in FIG. 3B, the switching lever 85 swings by the urging force of the torsion spring 86 when the innermost process cartridge 51 is removed from the drawer 8, and the cartridge abuts. The portion 85C is in contact with the inclined surface 82E of the side frame 82, so that the posture (non-contact position) inclined with respect to the horizontal plane is maintained.

<Structure of side panel>
Next, the structure of the side panel 22 that constitutes a part of the restriction mechanism that restricts the movement of the drawer 8 described above will be described. In the drawings to be referred to, FIG. 4 is a perspective view (a) in which the color laser printer with the front panel opened is viewed obliquely from above, and a perspective view (b) in which the side panel is partially broken.

  As shown to Fig.4 (a), the side panel 22 is arrange | positioned at the left-right both sides of the drawer 8, and supports the drawer 8 so that a movement in the front-back direction is possible. Specifically, as shown in FIG. 4B, the side panel 22 includes a first slide groove 22 </ b> A that slidably supports a first contact portion 85 </ b> B of the switching lever 85 of the drawer 8, and a flange of the drawer 8. A second slide groove 22B that slidably supports the portion 82A and the second contact portion 82B is formed.

  The first slide groove 22A is a groove that opens inward in the left-right direction and on the near side, and is formed in such a shape as to be bent downward at an appropriate position on the near side and then come out to the near side. Specifically, the first slide groove 22A is formed continuously with the guide groove A1 extending in the front-rear direction with the same width as the first contact portion 85B of the switching lever 85, and the guide groove A1. It is comprised by escape groove A2 arrange | positioned and shifted | deviated below groove | channel A1. The first slide groove 22A is bent in this manner, so that the first restriction wall A3 that contacts the first contact portion 85B of the switching lever 85 is disposed on the front side of the guide groove A1. It has become. Further, the clearance groove A2 is formed wider than the guide groove A1, specifically, with a width that does not contact the first contact portion 85B of the switching lever 85 located at the non-contact position.

  The second slide groove 22B is a groove that opens to the inner side and the front side in the left-right direction, and most of the rear side is at the height of the second contact portion 82B of the drawer 8 (height from the side surface of the side frame 82). The front portion is formed with a depth corresponding to the height of the flange portion 82 </ b> A of the drawer 8. Then, the bottom surface of the second slide groove 22B is formed in a stepped shape in this manner, so that the second slide groove 22B comes into contact with the second contact portion 82B of the drawer 8 at the front end thereof. A restriction wall B1 is arranged.

  The rear end face of the second slide groove 22B comes into contact with the second contact portion 82B of the drawer 8 so that the drawer 8 is stopped at the mounting position. Here, the “mounting position” refers to a position where each photosensitive drum 52 of the plurality of process cartridges 51 faces the conveyance belt 63 and printing is possible.

  Moreover, as shown to Fig.6 (a), the surface of the back side of 2nd control wall B1 is arrange | positioned before the surface of the back side of 1st control wall A3, and the near side of 2nd contact part 82B is arrange | positioned. The surface is disposed behind the surface on the near side of the first contact portion 85B. Thereby, before the 2nd contact part 82B contact | abuts to 2nd control wall B1, 1st contact part 85B contacts the 1st control wall A3. The arrangement of each surface is not limited to this, and the distance from the first contact portion 85B to the first restriction wall A3 is shorter than the distance from the second contact portion 82B to the second restriction wall B1. As long as it is, it may be arranged in any way.

<Operation of the regulation mechanism>
Next, the operation of the restriction mechanism (the first contact portion 85B, the first restriction wall A3, etc.) will be described. In the drawings to be referred to, FIG. 5 is a perspective view (a) showing a state in which the drawer is pulled out to an exchange position, a perspective view (b) showing a state in which the innermost process cartridge is removed from the drawer, and exchanging the drawer. It is a perspective view (c) which shows the state pulled out from the position to the jam processing position. FIG. 6 is a cross-sectional view taken along line YY of FIG. 4B, and is a cross-sectional view (a) showing a state in which the first contact portion is in contact with the first restriction wall, and a first view from the first restriction wall. They are sectional drawing (b) which shows the state from which 1 contact part removed, and sectional drawing (c) which shows the state which the 2nd contact part contacted the 2nd control wall.

  As shown in FIG. 4A and FIG. 5A, when the front cover 21 of the color laser printer 1 is opened and the drawer 8 is pulled out, first, as shown in FIG. The drawer 8 is stopped at the replacement position by the contact portion 85B contacting the first restriction wall A3 of the side panel 22. Here, the “exchange position” means a position where all of the plurality of process cartridges 51 are exposed to the outside of the apparatus main body 2 and can be exchanged. Since the drawer 8 is caught by the first restriction wall A3 at this replacement position, the user can easily replace each process cartridge 51 without supporting the drawer 8.

  Thereafter, when the innermost process cartridge 51 is removed from the drawer 8 as shown in FIG. 5B, the switching lever 85 is tilted by the torsion spring 86 as shown in FIG. The first contact portion 85B comes off from the regulation wall A3. Thereby, the drawer 8 can be further pulled out.

  When the drawer 8 is further pulled out from the replacement position as shown in FIG. 5C, the second contact portion 82B of the drawer 8 comes into contact with the second restriction wall B1 as shown in FIG. 6C. Thus, the drawer 8 is stopped at the jam processing position outside the replacement position. As a result, the gap α (see FIG. 6B) formed by removing the innermost process cartridge 51 is expanded to the gap β (see FIG. 6C) by the movement of the drawer 8. The user can easily perform jam processing from the large gap β.

According to the above, the following effects can be obtained in the present embodiment.
Since the process cartridge 51 can be exchanged without supporting the drawer 8 at the exchange position, the exchange work of the process cartridge 51 can be facilitated. Further, since it is possible to perform the jam processing without removing the drawer 8 from the apparatus main body 2, it is more complicated to install a heavy drawer according to the drawer outlet of the apparatus main body than the method of removing the jam and performing the jam processing. Therefore, the jam processing can be facilitated.

  Since the end portion of the switching lever 85 where the first contact portion 85B is formed extends farther than the rear frame 83 (frame body), the drawer 8 can be pulled out at the exchange position. . Therefore, the gap between the innermost process cartridge 51 and the apparatus main body 2 can be made relatively large, and the innermost process cartridge 51 can be easily attached and detached.

  Since the second contact portion 82B is formed at the end on the back side of the side frame 82 (the tip of the extending portion), the drawer 8 can be pulled out at the jam processing position. Therefore, the clearance β at the jam processing position can be increased to facilitate the jam processing.

  Since the first abutting portion 85B is configured to be removed from the first restriction wall A3 simply by removing one process cartridge 51, only one process cartridge 51 needs to be removed at the time of jam processing. Compared with a structure in which the first contact portion 85B is detached from the first restriction wall A3 by removing 51, the jam processing can be facilitated.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above embodiment, the switching lever 85 is swung by engaging the one process cartridge 51 and the switching lever 85 located on the innermost side. However, the present invention is not limited to this, and Two or more process cartridges 51 positioned on the side and the switching lever 85 may be engaged to swing the switching lever 85.

  In the above-described embodiment, the torsion spring 86 that constantly urges the switching lever 85 to the non-contact position is provided as a part of the regulation mechanism. However, the present invention is not limited to this, and the torsion spring 86 is not provided. You may comprise so that the switching lever 85 may always incline to a non-contact position with the dead weight of the switching lever 85. FIG.

  In the above-described embodiment, the torsion spring 86 is employed as the biasing member. However, the present invention is not limited to this, and the first contact portion 85B of the switching lever 85 is always pressed (or pulled) toward the non-contact position. ) A coil spring or a leaf spring may be employed.

  In the embodiment, the substantially central portion of the switching lever 85 is rotatably supported, the first contact portion 85B is provided at one end portion, and the process cartridge 51 is brought into contact with the other end portion. It is not limited to. For example, one end portion of the switching lever may be rotatably supported, a first contact portion may be provided at the other end portion, and the process cartridge may be in contact with the center portion.

In the above embodiment, the present invention is applied to the color laser printer 1, but the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.
In the above-described embodiment, paper P such as thick paper, postcard, and thin paper is used as an example of the recording sheet. However, the present invention is not limited to this, and may be, for example, an OHP sheet.

DESCRIPTION OF SYMBOLS 1 Color laser printer 2 Apparatus main body 8 Drawer 22 Side panel 22A 1st slide groove 22B 2nd slide groove 51 Process cartridge 52 Photosensitive drum 63 Conveyor belt 81 Front frame 82 Side frame 82B 2nd contact part 83 Rear frame 85 Switching lever 85B First contact portion 85C Cartridge contact portion 85D Spring engagement portion 86 Torsion spring A1 Guide groove A2 Relief groove A3 First restriction wall B1 Second restriction wall P Paper

Claims (5)

The device body;
A plurality of process cartridges having a photosensitive drum on which an electrostatic latent image is formed and arranged in parallel in one direction;
A conveying belt disposed opposite to each photosensitive drum of the plurality of process cartridges and conveying a recording sheet to and from each photosensitive drum;
A moving member that holds the plurality of process cartridges and that can be pulled out in a parallel direction of the process cartridges with respect to the apparatus main body;
An image forming apparatus comprising a restriction mechanism for restricting movement of the moving member,
The moving member is
A mounting position where the photosensitive drums of the plurality of process cartridges face the conveyance belt, a replacement position where all of the plurality of process cartridges are exposed to the outside of the apparatus main body and can be replaced, and further than the replacement position. It is configured to be movable between the outside jam processing position in the parallel direction,
The regulation mechanism is
A first restriction wall provided in the apparatus main body to stop the movement of the moving member at the exchange position;
A second restriction wall provided in the apparatus main body to stop the movement of the moving member at the jam processing position;
A switching lever supported rotatably on the moving member;
A first contact portion that is movable between a contact position that contacts the first restriction wall and a non-contact position that deviates from the first restriction wall by being provided on the switching lever;
A second abutting portion provided on the moving member and abutting against the second regulating wall;
When a predetermined number of process cartridges located on the most upstream side in the pulling direction of the moving member among the plurality of process cartridges are mounted on the moving member, the switching lever is pressed by the predetermined number of process cartridges. Thus, the image forming apparatus is configured such that the first contact portion is held at the contact position.   The image forming apparatus according to claim 1, wherein the restriction mechanism further includes a biasing member that biases the first contact portion to a non-contact position. The moving member is
In order to collectively support the plurality of process cartridges, a frame surrounding the plurality of process cartridges is provided,
The image according to claim 2, wherein the switching lever extends to the upstream side in the pull-out direction from the frame body, and the first contact portion is located upstream from the frame body. Forming equipment. The frame body is provided with an extending portion extending to the upstream side in the pull-out direction,
The image forming apparatus according to claim 3, wherein the second contact portion is provided in the extension portion. The image forming apparatus according to claim 1, wherein the predetermined number of process cartridges is one process cartridge located on the most upstream side in the pull-out direction.

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