JP5354371B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which employs a configuration in which a latent image carrier unit can be attached to and detached from an apparatus body in a direction orthogonal to an axial direction of a revolving shaft of the latent image carrier, and the cost reduction and the size reduction of the apparatus are achieved as a whole. <P>SOLUTION: A printer 100 includes a unit support member which supports a process unit 2 inserted in an installation space in a downward direction orthogonal to the axial direction, a support member moving mechanism which moves the unit support member along the axial direction, and a drive transmission part which is disposed at a left wall 110L and transmits drive to a drive part in the process unit 2. In the printer 100, in a state that the process unit 2 is inserted in the installation space, the drive part and the dive transmission part are separated from each other, and the unit support member is moved toward the drive transmission part together with the process unit 2 by a support member slide mechanism to drive-joint a driven coupling of the process unit 2 and a drive coupling of the body side of the printer 100. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

2. Description of the Related Art Conventionally, an image forming process in an image forming apparatus is a method in which a surface of a moving latent image carrier is uniformly charged by a charging device, and an exposure device irradiates the surface of the uniformly charged latent image carrier. Thus, an electrostatic latent image is formed on the surface of the latent image carrier. The developing device supplies toner to the electrostatic latent image, whereby a toner image is formed on the surface of the latent image carrier. The toner image formed by such an image forming process is formed on a recording medium by a transfer unit directly from the latent image carrier or via an intermediate transfer member.
In general, many of the parts constituting the image forming process have a shorter life than the apparatus main body parts. Therefore, a process cartridge as a latent image carrier unit that integrally supports a plurality of members including at least a latent image carrier among components constituting the image forming process can be attached to and detached from the apparatus main body. There is known an image forming apparatus that replaces components constituting an image forming process whose life has been approached by exchanging. In this type of image forming apparatus, a part of the exterior is opened to expose the installation space in which the process cartridge is installed, and the process cartridge is inserted into the installation space to be attached to the apparatus main body. The process cartridge is removed from the apparatus main body by pulling out the process cartridge.

  Since the axial length of the rotation axis of the latent image carrier that moves on the surface needs to be longer than the maximum width of the recording medium on which image formation is performed, the process cartridge has the rotation axis of the latent image carrier that moves endlessly. In general, the shape is long in the axial direction. For this reason, if the direction in which the process cartridge is attached to and detached from the apparatus main body is the direction along the axial direction, the process cartridge is moved in the longitudinal direction to be attached to and detached from the apparatus main body. Sexuality gets worse.

  In the image forming apparatuses described in Patent Documents 1 to 3, the direction in which the process cartridge is attached to and detached from the apparatus body is a direction orthogonal to the axial direction, and the direction in which the process cartridge is attached and detached is a direction along the axial direction. The operability at the time of attachment / detachment can be improved compared to the configuration.

In the configuration in which the process cartridge is attached to and detached from the apparatus main body, if a drive source is provided in the process cartridge that is periodically replaced, the running cost increases. For this reason, a configuration in which driving is transmitted from a driving source provided on the apparatus main body side to a driving unit in a process cartridge such as a latent image carrier is common.
In the configuration in which the direction in which the process cartridge is attached / detached is the direction along the axial direction, the driven side coupling is provided at the distal end on the insertion side of the process cartridge, and the back side of the wall surface forming the installation space of the apparatus main body Some drive-side couplings are provided at positions facing the driven-side couplings of the wall surface. In such a configuration, since the insertion direction of the process cartridge and the coupling direction of the coupling coincide, the coupling is coupled only by an operation of inserting the process cartridge into the installation space. Drive connection to the drive is made.
On the other hand, in the image forming apparatuses of Patent Documents 1 to 3, since the direction in which the process cartridge is inserted into the installation space is perpendicular to the axial direction, only the operation of inserting the process cartridge into the installation space is necessary. Drive connection by coupling cannot be performed.

The image forming apparatuses disclosed in Patent Documents 1 and 2 include a mechanism for moving the drive side coupling on the apparatus main body side in the axial direction. In such an image forming apparatus, after the operation of inserting the process cartridge into the installation space of the apparatus main body, the operation of moving the drive side coupling in the axial direction is performed, so that the driven coupling on the process cartridge side is connected. , Drive connection.
However, the configuration in which the drive side coupling is moved in the axial direction in this way is such that a part including the drive side coupling can be moved in the axial direction in the drive transmission mechanism that transmits the drive from the drive source to the drive side coupling. There is a need to. A mechanism that enables a part of the drive transmission mechanism to move in the axial direction and that can transmit the drive from the drive source to the movable part leads to complication of the apparatus and increases the cost.

The image forming apparatus disclosed in Patent Document 3 includes a driven gear that transmits driving to an internal driving unit at the distal end on the insertion side of the process cartridge, and the apparatus main body meshes with the driven gear at a position where the process cartridge abuts. A driving gear is provided. In this image forming apparatus, the driven side gear and the driving side gear are parallel to the rotational axis of the latent image carrier, and the process cartridge is inserted to a position where it abuts against the apparatus main body. The drive side gear meshes with each other to establish drive connection.
Unlike the image forming apparatuses disclosed in Patent Documents 1 and 2, the image forming apparatus disclosed in Patent Document 3 does not require a part of the drive transmission mechanism on the apparatus body side to be movable in the axial direction. Compared with the image forming apparatus, the configuration of the drive transmission mechanism is simplified, and the cost can be reduced.

However, in the image forming apparatus disclosed in Patent Document 3, the drive transmission from the drive source on the apparatus main body side to all of the drive units in the process cartridge is performed through the engagement of the driven side gear and the drive side gear. The load is concentrated at a position where the driven gear and the driving gear mesh with each other (hereinafter referred to as the meshing portion). For this reason, it has been necessary to form the meshing portion with a certain length in the direction parallel to the rotation axis of the driven gear and the driving gear so as to prevent the gear from being damaged at the meshing portion. For this reason, even if the process cartridges such as the axial length and diameter of the latent image carrier have the same configuration, the axial direction of the connecting portion between the driving side coupling and the driven side coupling in the driving coupling by the coupling The axial length of the meshing portion in the drive connection by the driven side gear and the drive side gear is longer than the length of.
In the image forming apparatus of Patent Document 3, the shaft length of the process cartridge is longer than that of the image forming apparatuses of Patent Document 1 and Patent Document 2 because the length of the engagement portion in the axial direction is longer than the length of the coupling connection portion. The length of the direction becomes longer. When the axial direction of the process cartridge becomes longer, the length of the apparatus main body that accommodates the process cartridge also becomes longer, leading to an increase in the size of the entire image forming apparatus.

  The present invention has been made in view of the above problems, and an object of the present invention is to have a configuration in which the latent image carrier unit can be attached to and detached from the apparatus main body in a direction orthogonal to the axial direction of the rotation axis of the latent image carrier. An object of the present invention is to provide an image forming apparatus capable of realizing cost reduction and downsizing of the entire apparatus.

In order to achieve the above object, the invention of claim 1 has a latent image carrier unit that integrally supports at least a plurality of members including the latent image carrier and is detachable from the apparatus main body. The latent image carrier unit is disposed in a direction perpendicular to the axial direction with respect to the installation space between the two main body wall portions that form the casings at both ends in the axial direction of the rotation axis of the latent image carrier of the apparatus main body. The latent image carrier unit is attached to and detached from the apparatus main body by inserting or withdrawing the apparatus, and the latent image carrier unit is attached to the apparatus main body with respect to the drive unit in the latent image carrier unit. In an image forming apparatus that transmits driving from a drive source on the main body side, a latent image carrier unit support member that supports the latent image carrier unit inserted in a direction orthogonal to the axial direction with respect to the installation space; The latent image carrier unit support member is A support member moving mechanism that moves along the axial direction, and a drive transmission unit that is disposed on one of the two main body wall portions and transmits driving to the drive unit in the latent image carrier unit. In a state where the image carrier unit is inserted into the installation space, the drive unit and the drive transmission unit are separated from each other, and the latent image carrier unit support member together with the latent image carrier unit by the support member moving mechanism. The drive unit and the drive transmission unit are drivingly connected by moving the motor to the drive transmission unit side.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the exterior of the apparatus main body is provided with an openable / closable member that can be opened and closed on the side surface of the apparatus or the upper surface of the apparatus in a direction orthogonal to the axial direction. The latent image writing device for writing a latent image on the surface of the latent image carrier thus moved moves integrally with the opening / closing member, and the installation space is exposed by opening the opening / closing member. The carrier unit can be attached to and detached from the apparatus main body.
According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the support member moving mechanism moves the latent image carrier unit support member toward the drive transmission unit in conjunction with an operation of closing the opening / closing member. It is provided with the interlocking mechanism to move.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the latent image carrier unit has a plurality of latent image carrier unit support members. It comprises two end support members that respectively support both ends of the latent image carrier unit in the axial direction, and the end support members are in the axial direction in a state where the latent image carrier unit is mounted on the apparatus main body. Positioning means for positioning the latent image carrier relative to the apparatus main body in a direction perpendicular to the main body.
According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the shape of the portion constituting the positioning means of the latent image carrier is the same for the two end support members. It is characterized by being the shape of.
According to a sixth aspect of the present invention, in the image forming apparatus according to the fourth or fifth aspect, the two end support members are formed of a metal material.
According to a seventh aspect of the invention, in the image forming apparatus according to any one of the fourth to sixth aspects, the two end support members are the same part.
The invention according to claim 8 is the image forming apparatus according to any one of claims 4 to 7, wherein the two end support members are integrally connected by a connecting member. To do.
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the support member for biasing the latent image carrier unit support member in a direction away from the drive transmission portion is provided. It is characterized by providing a biasing means.
According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the main body wall portion on the side provided with the drive transmission portion and the latent image carrier unit are arranged on the device. Fitting that the latent image carrier unit support member is fitted to each of the wall surfaces of the latent image carrier unit facing the main body wall portion when the main body is attached to the main body wall portion by moving to the drive transmission portion side. It is characterized by having a shape.
According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the first to tenth aspects, the positioning of the latent image carrier unit support member in the direction perpendicular to the axial direction with respect to the apparatus main body is performed as described above. A plurality of holes provided in the latent image carrier unit support member so as to penetrate in the axial direction, and a support member fixed to the main body wall so as to extend in the axial direction and passing through the hole. It is comprised by the movement guide pin, It becomes the structure which can adjust the position with respect to this main body wall part of at least 1 of this support member movement guide pin.

The image forming apparatus according to claim 1 further includes a support member moving mechanism that moves the latent image carrier unit support member along the axial direction, so that the latent image carrier unit is inserted into the installation space of the apparatus main body, and then the latent image carrier unit support member is moved. The latent image carrier unit supported by the image carrier unit support member can be moved in the axial direction perpendicular to the insertion direction. Then, the latent image carrier unit supporting member is moved along the axial direction to move the latent image carrier unit along the axial direction, and the drive unit and the drive transmission unit are drivingly connected. Therefore, it is possible to use drive coupling by coupling in which the axial direction and the coupling direction coincide. Further, since the latent image carrier unit is moved along the axial direction to perform drive connection, a part of the drive transmission mechanism can be moved in the axial direction, and the movable part can be driven from the drive source. Therefore, a complicated mechanism that can transmit the signal is unnecessary. Therefore, the configuration for transmitting the drive to the drive unit can be simplified, and the cost can be reduced.
Further, in the case of driving connection by coupling, the connecting portion is more than the engaging portion between the driven side gear and the driving side gear described above, including the separation for taking out the latent image carrier unit in the direction orthogonal to the axial direction. The length required in the axial direction can be shortened, and the axial length of the latent image carrier unit can be shortened. Since the axial direction of the latent image carrier unit can be shortened, the length of the apparatus main body that accommodates the latent image carrier unit can also be shortened, and the overall size of the image forming apparatus can be reduced.

  According to the present invention, after the latent image carrier unit is inserted into the installation space of the apparatus main body, the latent image carrier unit is moved by moving the latent image carrier along the axial direction and connected to drive the latent image carrier unit. With a configuration that can be attached and detached in a direction orthogonal to the axial direction of the rotation axis of the carrier, there is an excellent effect that it is possible to realize cost reduction and downsizing of the entire apparatus.

1 is a schematic configuration diagram of a printer according to an embodiment. Schematic explanatory drawing of a process unit. FIG. 3 is an explanatory perspective view of the printer with an upper cover opened. The perspective view of a process unit and a unit support member. Explanatory drawing of positioning of the process unit of the direction orthogonal to an axial direction. Explanatory drawing of the drive connection of the printer of this embodiment. Explanatory drawing before the insertion of the process unit with respect to installation space is completed. Explanatory drawing of the state which completed insertion of the process unit with respect to installation space. The perspective explanatory drawing of two apparatus main body side plates and a unit support member. Explanatory drawing of the structure which enabled adjustment of the position of the left end support member front side guide with respect to an apparatus main body left side plate. FIG. 3 is an explanatory diagram of a printer having an optical writing unit configuration different from that of the present embodiment. Explanatory drawing of the structure which moves a drive side coupling to an axial direction, and connects with a driven side coupling. Explanatory drawing of the structure by which a driven gear and a drive gear are meshed | engaged and drive connection is made by inserting a process unit to the position which abuts.

Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer 100) will be described.
First, the basic configuration of the printer 100 will be described. FIG. 1 is a schematic configuration diagram of the printer 100.
The printer 100 includes four process units 2 (Y, M, C, and K) for forming yellow, magenta, cyan, and black (hereinafter referred to as Y, M, C, and K) toner images. . These use Y, M, C, and K toners of different colors as the image forming material, but the other configurations are the same and are replaced when the lifetime is reached.

FIG. 2 is a schematic explanatory diagram of one process unit 2 among the four process units 2 (Y, M, C, K).
As shown in FIG. 2, the process unit 2 includes a drum-shaped photosensitive member 21 that is a latent image carrier, a drum cleaning device 24, a static elimination device (not shown), a charging device 23, a developing device 22 that is a developing unit, and the like. ing. The process unit 2, which is a latent image carrier unit, can be attached to and detached from the printer 100, and consumable parts constituting the image forming process can be replaced at a time.

The charging device 23 uniformly charges the surface of the photoconductor 21 that is rotated clockwise in the drawing by a driving unit (not shown). The surface of the uniformly charged photoreceptor 21 is exposed and scanned by the laser light L emitted from the optical writing unit 1 which is a latent image writing device, and electrostatic latent images corresponding to the respective colors are written. The electrostatic latent image is developed into a toner image of each color by the developing device 22. Then, the toner images of the respective colors formed on the respective photoreceptors 21 of the four process units 2 are primarily transferred onto an intermediate transfer belt 31 described later.
The drum cleaning device 24 removes transfer residual toner adhering to the surface of the photoconductor 21 after the primary transfer process. Further, a static elimination device (not shown) neutralizes residual charges on the photoreceptor 21 after cleaning. By this charge removal, the surface of the photoreceptor 21 is initialized and prepared for the next image formation.

  The developing device 22 includes a hopper unit 221 that stores toner and a developing unit 223. The hopper unit 221 includes an agitator 222 that is rotationally driven by a driving unit (not shown), and a communication hole 224 that connects the hopper unit 221 and the developing unit 223 is formed below the agitator 222 of the hopper unit 221. . The toner in the hopper unit 221 moves toward the developing unit 223 by its own weight while being agitated by the rotation of the agitator 222.

  Below the communication hole 224 in the developing unit 223 of the developing device 22, an agitation paddle 225 that agitates the toner supplied from the hopper unit 221 to the developing unit 223 by being rotated by a driving unit (not shown) is disposed. A developing roller 226 that rotates opposite to the photosensitive member 21 is disposed. Further, below the agitation paddle 225, a toner supply roller 227 for supplying toner supplied into the developing unit 223 to the developing roller 226 by being rotated by a driving unit (not shown) is disposed. Further, a thinning blade 228 whose tip is in contact with the surface of the developing roller 226 is disposed.

The toner moved from the hopper unit 221 to the developing unit 223 moves toward the toner supply roller 227 by its own weight while being stirred by the rotation of the stirring paddle 225. The toner supply roller 227 has a metal cored bar and a roller portion made of foamed resin or the like coated on the surface thereof, and rotates while adhering the toner in the developing portion 223 to the surface of the roller portion. To do. The toner attached to the toner supply roller 227 is supplied to the surface of the development roller 226 at the contact portion between the development roller 226 and the toner supply roller 227. When the toner supplied from the developing roller 226 passes through the contact position between the surface of the developing roller 226 and the thinning blade 228 as the developing roller 226 rotates, the layer thickness on the surface of the developing roller 226 is increased. Is regulated. Then, the toner on the developing roller 226 after the regulation of the layer thickness adheres to the electrostatic latent image on the surface of the photoconductor 21 in the developing area which is a contact portion between the developing roller 226 and the photoconductor 21. By this adhesion, the electrostatic latent image is developed with toner, and a toner image is formed on the surface of the photoreceptor 21.
The toner image is formed by such a process in each process unit 2 (Y, M, C, K) for Y, M, C, K, and each photoconductor 21 (Y, M, C, K). Y, M, C, and K toner images are respectively formed on the surface.

  As shown in FIG. 1, the optical writing unit 1 is disposed above the process unit 2 (Y, M, C, K) in the vertical direction. The optical writing unit 1 which is a latent image writing means is a photosensitive member 21 (Y, M, C, K) in the process unit 2 (Y, M, C, K) by a laser beam L emitted from a laser diode based on image information. C, K) is optically scanned. By this optical scanning, electrostatic latent images for Y, M, C, and K are formed on the photoreceptor 21 (Y, M, C, K). The optical writing unit 1 polarizes laser light emitted from a light source in a main scanning direction by a polygon mirror (not shown) that is rotationally driven by a polygon motor (not shown), and passes each photoconductor through a plurality of optical lenses and mirrors. 21 (Y, M, C, K).

  As shown in FIG. 1, an intermediate transfer belt 31 as an endless intermediate transfer member is stretched below the process unit 2 (Y, M, C, K) in the vertical direction, and counterclockwise in FIG. A transfer unit 3 that moves endlessly is disposed. In addition to the intermediate transfer belt 31, the transfer unit 3 serving as transfer means includes a driving roller 33, a driven roller 35, four primary transfer rollers 32 (Y, M, C, K), a secondary transfer roller 34, a not-shown illustration. A belt cleaning device is provided.

  The intermediate transfer belt 31 is stretched by a driving roller 33, a driven roller 35, a cleaning backup roller (not shown), and four primary transfer rollers 32 (Y, M, C, K) disposed inside the loop. . The intermediate transfer belt 31 moves endlessly in the counterclockwise direction in FIG. 1 by the rotational force of the drive roller 33 that is driven to rotate in the counterclockwise direction in FIG.

  The four primary transfer rollers 32 (Y, M, C, K) sandwich an endlessly moving intermediate transfer belt 31 between the photosensitive members 21 (Y, M, C, K). By this sandwiching, primary transfer nips for Y, M, C, and K where the front surface of the intermediate transfer belt 31 and the photoreceptors 21 (Y, M, C, and K) contact each other are formed.

  A primary transfer bias is applied to the primary transfer roller 32 (Y, M, C, K) by a transfer bias power source (not shown), whereby the photosensitive member 21 (Y, M, C, K) is statically moved. A transfer electric field is formed between the electrostatic latent image and the primary transfer roller 32 (Y, M, C, K). Instead of the primary transfer roller 32 (Y, M, C, K), a transfer charger, a transfer brush, or the like may be employed.

  When the Y toner formed on the surface of the Y photoconductor 21Y of the Y process unit 2Y enters the Y primary transfer nip as the Y photoconductor 21Y rotates, the transfer electric field and the nip pressure act. As a result, primary transfer is performed from the Y photoreceptor 21 </ b> Y onto the intermediate transfer belt 31. When the intermediate transfer belt 31 on which the Y toner image is primarily transferred in this way passes through the primary transfer nip for M, C, K along with the endless movement, the photoreceptor 21 (M, C, K). The upper M, C, K toner images are sequentially superimposed on the Y toner image and primarily transferred. A four-color toner image is formed on the intermediate transfer belt 31 by this primary transfer of superposition. That is, in the printer 100, the original image to be printed is separated into an arbitrary number of colors, and each image is formed by an individual image forming unit, and then superimposed on the intermediate transfer belt 31.

  The secondary transfer roller 34 of the transfer unit 3 is disposed outside the loop of the intermediate transfer belt 31, and sandwiches the intermediate transfer belt 31 with the driven roller 35 inside the loop. By this sandwiching, a secondary transfer nip where the front surface of the intermediate transfer belt 31 and the secondary transfer roller 34 abut is formed. A secondary transfer bias is applied to the secondary transfer roller 34 by a transfer bias power source (not shown). By this application, a secondary transfer electric field is formed between the secondary transfer roller 34 and the driven roller 35 connected to the ground.

Below the transfer unit 3 in the vertical direction, a paper feed cassette 6 accommodating a plurality of recording papers P as recording media in a bundle of sheets is slidably attached to the housing of the printer 100. Has been. Specifically, as indicated by an arrow D in FIG. 1, the paper feed cassette 6 is slidable so as to be pulled out to the front side of the printer 100.
The paper feed cassette 6 has a paper feed roller 5 in contact with the uppermost recording paper P of the paper bundle, and the recording paper is rotated by rotating it in a counterclockwise direction in the figure at a predetermined timing. P is sent out toward the paper feed path 51.

  Near the downstream end of the paper feed path 51, a registration roller pair 4 is provided. The registration roller pair 4 stops the rotation of both rollers as soon as the recording paper P delivered from the paper feed cassette 6 is sandwiched between the rollers. Then, rotation driving is resumed at a timing at which the sandwiched recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 31 in the above-described secondary transfer nip, and the recording paper P is directed to the secondary transfer nip. Send it out.

  The four-color toner image on the intermediate transfer belt 31 brought into close contact with the recording paper P at the secondary transfer nip is secondarily transferred onto the recording paper P under the influence of the secondary transfer electric field and nip pressure, and the recording paper Combined with the white color of P, a full color toner image is obtained. The recording paper P having the full-color toner image formed on the surface in this way is separated from the secondary transfer roller 34 and the intermediate transfer belt 31 by the curvature when passing through the secondary transfer nip. Then, the toner is fed into a fixing device 7 to be described later via a post-transfer conveyance path 52.

  Untransferred toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 31 that has passed through the secondary transfer nip. This is cleaned from the belt surface by a belt cleaning device (not shown) in contact with the front surface of the intermediate transfer belt 31. A cleaning backup roller (not shown) disposed inside the loop of the intermediate transfer belt 31 backs up the cleaning of the belt by the belt cleaning device from the inside of the loop.

  The fixing device 7 forms a fixing nip by a fixing roller 7a including a heat source such as a halogen lamp (not shown) and a pressure roller 7b that rotates while contacting with the fixing roller 7a with a predetermined pressure. The recording paper P fed into the fixing device 7 is sandwiched between the fixing nips so that the surface carrying the unfixed toner image is in close contact with the fixing roller 7a. Then, the toner in the toner image is softened by the influence of heating and pressurization, and the full-color image is fixed on the recording paper P.

  The recording paper P discharged from the fixing device 7 passes through the post-fixing conveyance path 53 and then reaches a branch point between the paper discharge path 54 and the pre-reversal conveyance path 55. A switching claw (not shown) is provided at this branch point, and at the timing when the recording paper P is sent out from the fixing device 7, the switching claw is in a position to direct the recording paper P toward the paper discharge path 54. As a result, the recording paper P enters the paper discharge path 54 from the post-fixing conveyance path 53 and is sandwiched between the rollers of the paper discharge roller pair 8.

  When the single-sided print mode is set by an input operation to an operation unit (not shown) equipped with a numeric keypad or a control signal sent from a personal computer (not shown), the paper is sandwiched between the discharge roller pair 8. The recording paper P is discharged out of the apparatus as it is. Then, it is stacked on the stack portion 9 which is the upper surface of the upper cover 12 of the housing.

  On the other hand, when the duplex printing mode is set, when the trailing edge of the recording paper P conveyed in the paper discharge path 54 while being sandwiched between the paper discharge roller pair 8 passes through the post-fixing conveyance path 53. A switching claw (not shown) moves to a position where the paper discharge path 54 and the conveyance path 55 before reversal are opened, and closes between the paper discharge path 54 and the conveyance path 53 after fixing. At substantially the same time, the paper discharge roller pair 8 starts to rotate in the reverse direction. Then, the recording paper P is conveyed while the rear end side is directed to the top, and enters the pre-reversal conveyance path 55.

  FIG. 1 shows the printer 100 from the side. The right side in FIG. 1 is the front surface of the printer 100, and the left side is the rear surface. The front surface of the printer 100 is a reversing unit 40 that can be opened and closed with respect to the casing body of the printer 100 by rotating about a rotation shaft 40a. When the paper discharge roller pair 8 rotates in the reverse direction, the recording paper P enters the pre-reversal conveyance path 41 of the reversing unit 40 and is conveyed from the upper side to the lower side in the vertical direction. Then, after passing between the rollers of the pair of reverse conveying rollers 43, it enters the reverse conveying path 44 that is curved in a semicircular shape. Furthermore, while the upper and lower surfaces are reversed as the sheet is conveyed along the curved shape, the traveling direction from the upper side in the vertical direction to the lower side is also reversed, and conveyed from the lower side in the vertical direction toward the upper side. Is done. Thereafter, the toner enters the secondary transfer nip again through the above-described paper feed path 51. Then, after the full-color image is secondarily transferred collectively to the other surface, the post-transfer conveyance path 52, the fixing device 7, the post-fixation conveyance path 53, the paper discharge path 54, and the paper discharge roller pair 8 are sequentially passed. And discharged outside the machine.

  The reversing unit 40 described above has a front cover 45 and a swinging body 46. Specifically, the front cover 45 of the reversing unit 40 is supported so as to rotate about a rotation shaft 40a provided in a housing of the printer 100 main body. By this rotation, the front cover 45 opens and closes with respect to the housing together with the swinging body 46 held therein. As shown by a two-dot chain line in the figure, when the front cover 45 is opened together with the swinging body 46 therein, the paper feed path 51, the secondary transfer nip, and the like formed between the reversing unit 40 and the printer main body side, The post-transfer conveyance path 52, the fixing nip, the post-fixation conveyance path 53, and the paper discharge path 54 are vertically divided into two and exposed to the outside. Thereby, jammed paper in the paper feed path 51, the secondary transfer nip, the post-transfer conveyance path 52, the fixing nip, the post-fixation conveyance path 53, and the paper discharge path 54 can be easily removed.

  The swing body 46 is supported by the front cover 45 so as to rotate about a swing shaft (not shown) provided in the front cover 45 in a state where the front cover 45 is opened. When the swinging body 46 is opened with respect to the front cover 45 by this rotation, the pre-reverse conveyance path 55 and the reverse conveyance path 44 are vertically divided into two and exposed to the outside. As a result, the jammed paper in the pre-reversal conveyance path 55 and the reversal conveyance path 44 can be easily removed.

  The upper cover 12 of the housing of the printer 100 is supported so as to be rotatable about a shaft member 61 as indicated by an arrow A in FIG. 1, and is rotated counterclockwise in the drawing to It will be in an open state. And the upper opening of a housing is exposed greatly.

  As shown in FIG. 1, when a side-by-side layout is adopted for the four process units 2 (Y, M, C, and K), the side-by-side photoconductors 21 (Y, M, C, and K) are used for the intermediate transfer belt 31. It is desirable to stretch in a horizontally long posture as shown in FIG. Then, the four process units 2 (Y, M, C, K) arranged side by side are disposed vertically above the intermediate transfer belt 31 in the horizontally long position as shown in FIG. 1, or the layout of FIG. On the contrary, it is disposed below the intermediate transfer belt 31. Here, in the case where the optical writing unit 1 is disposed below the intermediate transfer belt 31, the optical writing unit 1 is in a horizontally long posture so that optical scanning with respect to the four photosensitive members 21 (Y, M, C, K) is possible. In addition, it is necessary to dispose them below each process unit. Contrary to the layout shown in FIG. 1, the optical writing unit 1, the process units 2 (Y, M, C, K), and the intermediate transfer belt 31 are sequentially stacked from the lower side to the upper side in the vertical direction. It is. However, in the configuration in which the recording paper P is conveyed from the lower side to the upper side in the vertical direction, it is necessary to provide the fixing device 7 above the intermediate transfer belt 31 that forms the secondary transfer nip. If the layout shown in FIG. 1 is reversed, the left side of the fixing device 7 in the figure becomes a blank space. For this reason, it is difficult to reduce the size and space of the apparatus.

  On the other hand, in the printer 100 of the present embodiment, as shown in FIG. 1, four process units 2 (Y, M, C, K) are arranged side by side and arranged above the intermediate transfer belt 31 in a landscape orientation. The set layout is adopted. In such a layout, as shown in the figure, the horizontally oriented optical writing unit 1 is disposed above the four process units 2 (Y, M, C, K). Then, four process units 2 (Y, M, C, K) and an optical writing unit 1 are arranged on the side of the fixing device 7 as shown in FIG. 1, and a blank space is formed on the side of the fixing device. Can be avoided.

  In the printer 100, as described above, each process unit 2 (Y, M, C, K) is disposed above the intermediate transfer belt 31 from the viewpoint of miniaturization and space saving, and further optical writing is further provided thereon. Insert unit 1 is provided. Therefore, the optical writing unit 1 is withdrawn from directly above each process unit. In the printer 100, the optical writing unit 1 is held on the lower surface side of the upper cover 12 that can be opened and closed, and the optical writing unit 1 is moved to each process unit 2 (Y, M, C) as the upper cover 12 is opened and closed. , K) is set aside from above or set directly above.

FIG. 3 is an explanatory perspective view of the printer 100 with the upper cover 12 opened.
As shown in FIG. 3, in the printer 100, an upper cover 12 that is an exterior of the upper surface of the apparatus is configured to be freely opened, and the optical writing unit 1 is attached thereto. In this way, the installation space of each process unit 2 (Y, M, C, K) can be exposed only by opening the upper cover 12, which is an open portion of the upper surface, and as shown in FIG. Each process unit 2 (Y, M, C, K) can be attached and detached.
In the printer 100, when feeding paper, the paper feed cassette 6 is pulled out to the front side of the printer 100 as shown by an arrow D in FIG. 1, and when a paper jam occurs, the front cover 45 is opened as shown by an arrow B in FIG. The conveyance path of the transfer paper P is exposed by rotating the printer 100 so as to be pulled toward the front side. When the process unit 2 is replaced, the upper cover 12 is rotated upward as indicated by an arrow A in FIG. With such a printer 100, all operations performed by the user can be performed from the front side of the printer 100, and a full front operation configuration can be realized.

FIG. 4 is a perspective explanatory view of the process support unit 11 and the process unit 2 that support each process unit 2 (Y, M, C, K) from below in the printer 100 as viewed from the same direction as FIG.
As shown in FIG. 4, the printer 100 has unit support members 11 (unit left end support member 11 </ b> L, unit right end support member 11 </ b> R) at both ends in the left-right direction (front and rear direction in FIG. 1) of the installation space of the process unit 2. Prepare.
When the upper cover is opened and the process unit 2 is inserted into the exposed installation space of the printer 100 from above, the lower end of the process unit 2 comes into contact with the unit support member 11, and the vertical positioning of the process unit 2 with respect to the printer 100 is roughly performed. Is made.

In the printer 100, the toner images of the respective colors formed by the process units 2 (Y, M, C, K) are superimposed on the intermediate transfer belt 31. For this reason, if the position of the photosensitive member 21 is deviated from the ideal position of the primary transfer portion with respect to the intermediate transfer belt 31 that rotates, the image will be misaligned between colors and the image quality will be degraded.
Hereinafter, the positioning configuration of the process unit 2 with respect to the main body of the printer 100 in the direction orthogonal to the axial direction of the photosensitive member 21 will be described.
As shown in FIG. 4, the unit upper surface pressing members 91 (Y, M, C, and K) are located at positions facing the process units 2 (Y, M, C, and K) at both ends in the axial direction on the lower surface of the optical writing unit 1. K). When the upper cover 12 is closed from the state shown in FIG. 4, each unit upper surface pressing member 91 (Y, M, C, K) presses each process unit 2 (Y, M, C, K) as shown in FIG. To do.
FIG. 5 is an explanatory diagram of positioning of the process unit 2 with respect to the unit support member 11 in a direction orthogonal to the axial direction of the photoconductor 21.
The unit upper surface pressing member 91 presses the process unit 2 downward by an urging force of the unit upper surface pressing spring 92 as indicated by an arrow F in FIG. As shown in FIGS. 4 and 5, a positioning recess 112 is provided in the upper part of the unit support member 11, and the process unit 2 is fitted into the positioning recess 112. Then, by pressing the process unit 2 from above as indicated by an arrow F in FIG. 5, the lower end portion of the process unit 2 is inclined with respect to the positioning recess 112 as indicated by arrows F1 and F2 in FIG. Push down and hit. As a result, the process unit 2 is positioned in the direction perpendicular to the axial direction with respect to the unit support member 11, and the photosensitive member 21 provided in the process unit 2 is positioned in the direction perpendicular to the axial direction with respect to the printer 100 main body.

Further, the unit left end support member 11L and the unit right end support member 11R are made of metal and are the same member. By using the same member made of a metal that is not easily deformed, each photoconductor 21 can be kept parallel at least. For example, if the straight line connecting the two positioning recesses 112 facing each other at both ends in the axial direction is not perpendicular to the surface movement direction of the intermediate transfer belt 31 due to an assembly error at the time of manufacture, etc., the unit left end support The rotation axis of the photosensitive member 21 positioned by the member 11L and the unit right end support member 11R is also inclined with respect to the surface movement direction of the intermediate transfer belt 31. If the unit left end support member 11L and the unit right end support member 11R use the same member, the pitch width of the four positioning recesses 112 of the unit left end support member 11L and the four positioning recesses of the unit right end support member 11R are used. The pitch width of 112 is the same. Therefore, the four straight lines connecting the two positioning recesses 112 facing each other at both ends in the axial direction are always parallel, and the four photoconductors 21 (Y, M, C, K) positioned by the positioning recess 112 are parallel. I can keep it.
By keeping the four photoconductors 21 (Y, M, C, K) parallel, even if the position of the photoconductor 21 with respect to the intermediate transfer belt 31 is deviated from the ideal position, the four photoconductors 21 are subjected to the intermediate transfer. Since the same shift with respect to the belt 31, at least the image misalignment between colors can be greatly reduced.
Further, by using the unit support member 11 as a metal member, the component manufacturing accuracy can be made higher than that of resin or the like, and it is also possible to use it for grounding using conductivity. Furthermore, by using only the mold for forming the positioning recess 112 which is a positioning shape, the four positioning recesses 112 can be made the same shape even if they are not the same part, and the same effect can be obtained.

  As a problem caused by the colorization of the image forming apparatus, an image shift between colors is generally recognized as a big problem. There are various causes of this problem, but the positional accuracy of the photosensitive member, particularly the parallelism between the plurality of photosensitive members, has a great influence. For such a problem, in the printer 100 of the present embodiment, a metal member is used as the unit support member 11 having a shape for positioning the photoconductor 21, and further, the unit left end support member 11L and the unit right end support member are used. By making 11R the same member, the photoreceptor pitch is defined. As a result, image misregistration between colors is prevented, and quality improvement is achieved by improving image accuracy.

Next, the characteristic part of the printer 100 of this embodiment is demonstrated.
As shown in FIG. 1, the printer 100 forms an installation space for each process unit 2 (Y, M, C, K) between the left side wall part 110L and the right side wall part 110R. The left side wall 110L is provided with a drive transmission mechanism that transmits drive to the drive unit in the process unit 2. When the process unit 2 is inserted into the installation space from above, the drive unit, the drive transmission mechanism, Is a separated state. Then, the drive support mechanism in the left side wall part 110L and the drive part in the process unit 2 are slid by moving the unit support member 11 to the left side wall part 110L side in parallel with the axial direction by a support member moving mechanism described later. And drive coupled.

In recent years, downsizing of an image forming apparatus used near a user such as a printer has been remarkable. In addition, colorization of output images has been widely performed. Such an image forming apparatus is required to save space for installation in the vicinity of the user, and there is a high demand for not only downsizing of the apparatus size but also work from the front (full front operation). Moreover, it is desirable that there are few operation parts and that it can be handled by a simple operation so that an unfamiliar user does not perform an erroneous operation.
In response to such a request, in the printer 100 of the present embodiment, the upper cover 12 is configured to be freely opened, and the optical writing unit 1 is fixed to the upper cover 12. In this way, the process unit 2 can be exposed only by opening the upper cover 12, and the attaching / detaching operation can be performed as it is.
Examples of the image forming apparatus configured to move the exposure apparatus together with the upper opening to expose the process cartridge by opening the upper opening include the image forming apparatuses described in Patent Documents 1 to 3. it can.

  The image forming apparatuses disclosed in Patent Documents 1 and 2 include a mechanism for moving the drive side coupling on the apparatus main body side in the axial direction. In such an image forming apparatus, after the process cartridge is mounted on the apparatus main body, the drive side coupling is moved in the axial direction to be connected to the driven side coupling on the process cartridge side, thereby performing drive connection.

FIG. 12 is an explanatory diagram of a configuration in which the driving side coupling on the main body side of the printer 100 is moved in the axial direction and connected to the driven side coupling on the process unit 2 side which is a process cartridge.
The configuration shown in FIG. 12 includes a drive motor 16, a first gear 17, a second gear 18, and a drive side coupling slide mechanism 20 as drive transmission mechanisms. The first gear 17 has a first drive side coupling 20a connected to the photoconductor driven side coupling 21a of the photoconductor 21 in the process unit 2 as a rotary member having the same rotary shaft as the second gear 18, and the same rotary shaft as the second gear 18. As a rotating member, a second drive side coupling 20b connected to the development driven side coupling 22a of the development device 22 in the process unit 2 is provided. The first drive side coupling 20a and the second drive side coupling 20b are slidable from the position indicated by the solid line to the position indicated by the broken line by driving the drive side coupling slide mechanism 20.
Further, a left side fixing member 115L for fixing the unit left end support member 11L to the apparatus main body left side plate 14L that forms the left end of the installation space is provided.

In the configuration shown in FIG. 12, when the process unit 2 is attached to and detached from the printer 100 main body, the first drive side coupling 20a and the second drive side coupling 20b are in positions indicated by solid lines.
When the process unit 2 is mounted, if the process unit 2 is inserted into the installation space from above, the lower end of the process unit 2 hits the unit support member 11 (unit left end support member 11L in FIG. 12) and is supported. Next, the drive of the drive side coupling slide mechanism 20 is driven, and the first drive side coupling 20a and the second drive side coupling 20b are slid to the position of the broken line in the axial direction. As a result, the first driving side coupling 20a and the photoreceptor driven side coupling 21a are connected, and the second driving side coupling 20b and the development driven side coupling 22a are connected, and the drive transmission mechanism and the driving unit are connected. Are connected.
In the configuration shown in FIG. 12, in the connection between the first drive side coupling 20a and the photoreceptor driven side coupling 21a and the connection between the second drive side coupling 20b and the development driven side coupling 22a, the drive connection is performed. A coupling configuration is used. In this way, with the configuration using the coupling, a part including the driving side coupling of the members constituting the driving transmission mechanism such as the first driving side coupling 20a and the second driving side coupling 20b can be slid in the axial direction. Then, the apparatus becomes very complicated, and accuracy reduction due to increase in machine size, cost increase, and complicated mechanism cannot be avoided.

  The image forming apparatus disclosed in Patent Document 3 includes a driven gear that transmits driving to an internal driving unit at the front end in the mounting direction of the process cartridge, and is driven by the driven gear at a position where the process cartridge abuts on the apparatus body side. The drive side gearwheel which transmits is provided. In this image forming apparatus, the driven-side gear and the drive-side gear are driven so that the rotation shafts of the driven-side gear and the driving-side gear are parallel to the rotation shaft of the latent image carrier, and the process cartridge is brought into contact with the apparatus main body. Engage with the side gears to establish a drive connection.

FIG. 13 is an explanatory diagram of a configuration in which the driven gear and the driving gear are engaged with each other by inserting the process unit 2 to a position where it abuts against the main body of the printer 100, and the driving connection is established.
In the configuration shown in FIG. 13, when the process unit 2 is mounted on the printer 100 main body, when the process unit 2 is inserted into the installation space from above, the process unit 2 protrudes on the same axis as the rotation axis of the photosensitive member 21. The positioning part 211L hits the horizontal plane part of the apparatus main body left side plate 14L. At this time, the drive transmission which is a drive side gear which rotates to the rotation of the first gear 17 on the same rotation shaft as the first gear 17 and the drive gear 21G which is a driven side gear which transmits the drive to the drive unit in the process unit 2 The gear 17G engages with the engagement length E, and the drive connection is made.
In the configuration shown in FIG. 13, there is no configuration in which a part of the drive transmission mechanism is slid, and the drive connection is made only by the operation of mounting the process unit 2. Therefore, the configuration shown in FIG. It is advantageous to cost.

However, in the printer 100 having the configuration shown in FIG. 13 that is excellent in operability at the time of attaching and detaching the process unit 2 and is advantageous in low cost, the size of the apparatus main body, particularly the width in the axial direction (left and right direction of the printer 100) is large. There was a problem of getting bigger.
This is due to the following reason.
Since the drive transmission from the drive motor 16 which is the drive source on the printer 100 body side to all of the drive units in the process unit 2 is performed through the engagement between the drive transmission gear 17G and the drive gear 21G, the drive transmission gear 17G The load concentrates on the meshing portion with the drive gear 21G. For this reason, the length in the direction parallel to the rotation axis of the meshing portion (hereinafter referred to as the meshing length E) needs to have a certain length so as to prevent the gear from being damaged at the meshing portion. For this reason, even if the process unit 2 such as the axial length and diameter of the photosensitive member 21 is used in the same configuration, the axial length required for drive connection by the coupling shown in FIG. 12 is about 3 mm. In contrast, in the configuration shown in FIG. 13, the engagement length E is required to be 10 [mm] or more.
For this reason, the configuration shown in FIG. 13 is longer in the axial direction of the process unit 2 than the configuration shown in FIG. Further, in the configuration shown in FIG. 13, the position where the drive connection is performed is the back end in the insertion direction of the process unit 2, and only the shape required for the drive connection is a shape protruding from the axial direction of the process unit 2. In addition, other members cannot be provided in the space that forms the orbit of the shape required for the drive connection, and after the process unit 2 is mounted, the space becomes a blank space.

Further, in the case where the gear is connected as shown in FIG. 13 instead of the drive connection by coupling, the rotation axis of the photosensitive member 21 needs to be accurately positioned in order to expose the photosensitive member 21. In order to accurately position the photoconductor 21, a positioning unit 211 </ b> L that is fixed to the process unit 2 and exists on the axis of the photoconductor 21 is required. A member similar to the positioning portion 211L is also required on the right end side in the axial direction, and when the axial length of such a positioning shape is 10 mm on one side, the axial end ends A total of 20 [mm] space is required. Since the positioning portion 211L exists on the axis of the photosensitive member 21, it is arranged at a position on the back side in the insertion direction of the process unit 2, and in a space serving as a track of the positioning portion 211L when the process unit 2 is attached or detached. No other member can be provided, and after the process unit 2 is mounted, it becomes a blank space.
As described above, in the configuration shown in FIG. 13, the axial length of the process unit 2 becomes long, or a blank space is generated after the process unit 2 is mounted, so it is difficult to reduce the size. .
In the configuration shown in FIG. 13, the width W from the end portion of the primary transfer roller 32 in the axial direction to the end portion of the drive motor 16 is 76 [mm].

  Although the above-described problems caused by the configurations of FIGS. 12 and 13 can be solved by a configuration in which the process cartridge is attached to and detached from the photosensitive member in the axial direction, the configuration is inferior in operability in the first place and the positioning configuration is complicated. Problems such as the increase in size and the size of the image forming apparatus itself cannot be solved. For this reason, there is a demand for an image forming apparatus that maintains the excellent operability at the time of replacement of the process cartridge, and further realizes downsizing of the entire apparatus at low cost, such as the image forming apparatuses described in Patent Documents 1 and 2. It is done.

FIG. 6 is an explanatory diagram of drive coupling in the state where the process unit 2 is mounted in the printer 100 of the present embodiment.
7 and 8 are explanatory diagrams of a procedure for mounting the process unit 2 to the apparatus main body of the printer 100 according to the present embodiment. 9 is a perspective explanatory view of the apparatus main body left side plate 14L and the apparatus main body right side plate 14R that form both axial ends of the installation space of the process unit 2, and the unit support member 11 that supports the process unit 2 from below. It is.

As described above, the printer 100 includes the drive transmission mechanism that transmits the drive to the drive unit in the process unit 2 in the left side wall portion 110L. And as shown in FIG. 6, the drive motor 16, the 1st gear 17, and the 2nd gear 18 are provided as a drive transmission mechanism. The first gear 17 has a first drive side coupling 20 a that is connected to the photosensitive member driven side coupling 21 a of the photosensitive member 21 in the process unit 2 as a rotating member having the same rotational axis as the second gear 18. As a rotating member of the rotating shaft, a second drive side coupling 20b connected to the development driven side coupling 22a of the developing device 22 in the process unit 2 is provided.
Unlike the configuration described with reference to FIG. 12, the printer 100 of the present embodiment has a configuration in which the first drive side coupling 20 a and the second drive side coupling 20 b cannot slide in the axial direction.
The first drive side coupling 20a protrudes from the first side plate opening 1401 in FIG. 9 to the installation space side, and the second drive side coupling 20b extends from the second side plate opening 1402 in FIG. Protrudes to the side.

The printer 100 according to this embodiment is fixed to the apparatus main body left side plate 14L, is fitted to the unit left end support member 11L, and supports the unit left end support member 11L so as to be slidable in the axial direction with respect to the apparatus main body left side plate 14L. A left end support member guide 15L is provided. Similarly to the left end support member guide 15L, the right end support member (not shown) is fitted to the unit right end support member 11R and supports the unit right end support member 11R so as to be slidable in the axial direction with respect to the apparatus main body right side plate 14R. A guide 15R is provided on the apparatus main body right side plate 14R.
As shown in FIG. 9, the unit left end support member 11L and the unit right end support member 11R are connected by a front connection member 13F and a rear connection member 13R, and are configured to slide integrally along the axial direction. It has become.
The left end support member guide 15L includes a support member urging spring 19 that urges the unit left end support member 11L in a direction separating from the apparatus main body left side plate 14L (in the direction of arrow J in FIG. 8).

  As shown in FIG. 3, a lever member 93 is provided on the upper surface of the right side wall portion 110R. The printer 100 presses the unit right end support member 11R away from the apparatus main body right side plate 14R by the lever member 93 being tilted in the direction of arrow K in FIG. 3, and the unit left end support member 11L and the unit right end support member 11R. Is provided with a support member slide mechanism (not shown) that slides toward the apparatus main body left side plate 14L side. As shown in FIG. 3, when the upper cover 12 is opened, the lever member 93 is raised, and when the upper cover 12 is closed from the state shown in FIG. 3, the upper cover 12 pushes the lever member 93, and the lever The member 93 falls in the direction of arrow K in FIG. That is, the unit support member 11 (unit left end support member 11L and unit right end support member 11R) slides toward the apparatus main body left side plate 14L side in conjunction with the operation of closing the upper cover 12 from the state of FIG. .

  In the printer 100 of this embodiment, when the process unit 2 is mounted on the apparatus main body, as shown in FIG. 7, the track of the process unit 2, the first drive side coupling 20a, and the second drive side coupling 20b overlap. The process unit 2 is inserted into the installation space so that it does not occur. When the process unit 2 is inserted further downward as indicated by an arrow H from the state of FIG. 7, the lower end of the process unit 2 abuts against the unit support member 11 as shown in FIG. 8. At this time, since the unit support member 11 is urged in the direction of arrow J in FIG. 8 by the support member urging spring 19, drive connection is not established.

By performing the operation of closing the upper cover 12 from the state shown in FIG. 8, the upper cover 12 tilts the lever member 93 in the direction of the arrow K in FIG. 3, and the unit support member 11 and the process unit 2 are operated by the operation of the support member slide mechanism. Slides in the direction of arrow I in FIG. When the process unit 2 slides in the direction of arrow I in FIG. 8, the photoreceptor driven side coupling 21a and the first drive side coupling 20a are connected, and the development driven side coupling 22a and the second drive side coupling are connected. 20b is connected. This establishes drive connection.
Along with this sliding operation, the rotation direction positioning convex portion 205 of the process unit 2 is fitted into the rotation direction positioning hole 1403 provided in the apparatus main body left side plate 14L.
Further, when the upper cover 12 is completely closed, the state shown in FIG. 6 is obtained, and the unit upper surface pressing member 91 presses the upper surface of the process unit 2, and the process unit 2 with respect to the printer 100 main body as described with reference to FIG. Positioning in a direction perpendicular to the axial direction is performed.

In this way, the upper cover 12 is closed from the state shown in FIG. 8, so that the drive connection is performed, and the pressing in the direction of the arrow I in the drawing by the support member sliding mechanism and the biasing force of the support member biasing spring 19 are performed. Positioning is performed in the axial direction of the process unit 2, and the unit upper surface pressing member 91 presses the upper surface of the process unit 2, thereby positioning the process unit 2 in the direction orthogonal to the axial direction with respect to the printer 100 main body. Is done. Further, the rotation direction positioning convex portion 205 is fitted into the rotation direction positioning hole 1403, whereby the rotation direction of the photoconductor 21 around the rotation axis can be determined. Thereby, the positioning of the process unit 2 with respect to the printer 100 is achieved.
In the printer 100 of the present embodiment, the axial length required for drive connection is 3 [mm] of the coupling and 2 [mm] which is a distance enough to completely retract the process unit 2 from the drive side coupling. It was 5 [mm] added. Therefore, the axial length required for drive connection can be made shorter than the configuration of FIG. 13 that requires 10 [mm] or more as the engagement length E. Further, since the space required for the positioning portion 211L having the configuration shown in FIG. 13 is not necessary, the entire axial length of the process unit 2 can be shortened.
In the printer 100 of the present embodiment shown in FIG. 6, the width W from the axial end of the primary transfer roller 32 to the end of the drive motor 16 is 55 [mm], which is shorter than the configuration shown in FIG. We were able to.

  In the state in which the upper cover 12 is opened, there is no restriction against the urging of the support member urging spring 19. Therefore, the process unit 2 supported by the unit support member 11 by the urging of the support member urging spring 19. Is in a position where the drive connection is released. For this reason, when the upper cover 12 is opened, the process unit 2 can be pulled out as it is, and the user is not forced to perform an additional operation when the process unit 2 is replaced, thereby improving the operability at the time of replacement. can do.

The printer 100 is configured to slide the unit support member 11 in the axial direction together with the process unit 2 in conjunction with opening and closing of the upper cover 12 by a support member slide mechanism which is a link mechanism (not shown). With such a configuration, the user can move the process unit 2 in the axial direction by opening or closing the upper cover 12, so that the configuration has excellent operability when replacing the process unit 2. This can be achieved with an inexpensive configuration that does not use an actuator or the like.
The structure for sliding the unit support member 11 in the axial direction together with the process unit 2 is not limited to the one using the link mechanism, and an actuator that drives based on some trigger and slides the unit support member 11 in the axial direction. The structure to be used may be used.

In the printer 100 of this embodiment, the left end support member guide 15L is fixed to the apparatus main body left side plate 14L. However, the position of the left end support member guide 15L with respect to the apparatus main body left side plate 14L can be adjusted. Also good.
FIG. 10 is an explanatory diagram of a configuration in which the position of the left end support member front guide 15LF with respect to the apparatus main body left side plate 14L can be adjusted. In the configuration shown in FIG. 10, the left end support member front guide 15LF is crimped to the bracket member 60 and protrudes into the space between the side plates through the opening 1404 provided in the apparatus main body left side plate 14L, and the bracket member 60 faces the apparatus main body left side plate 14L. It is the structure positioned by being fixed.
The left side of the apparatus main body is prepared such that the fixed position is changed by this configuration, or the left end support member front side guide 15LF with respect to the bracket member 60 is previously crimped in a different position, or the left end support member front side guide 15LF having a different shape is crimped. The position of the left end support member front guide 15LF is adjustable with respect to the plate 14L.
The three support member guides 15 other than the left end support member front guide 15LF (the left end support member rear guide 15LR, the right end support member front guide 15RF, and the right end support member rear guide 15RR (not shown)) are side plates by caulking or the like. It is fixed to. With this configuration, not only high component accuracy is required, but also a method for reducing the image shift between colors can be selected by adjusting the guide member according to the inspection result after assembly.

  In the present embodiment, an example of the printer 100 that employs a one-component development method that develops a latent image using a one-component developer containing toner as a main component without including a magnetic carrier has been described. The present invention can also be applied to an image forming apparatus that employs a two-component developing method using a two-component developer containing toner.

  Further, the printer 100 is configured to move the optical writing unit 1 as the upper cover 12 is opened and closed. However, the optical writing unit 1 and the upper cover 12 are individually rotated to provide four process units 2. The present invention is also applicable to an image forming apparatus that is retracted from a facing position with (Y, M, C, K). The present invention can also be applied to an image forming apparatus in which the optical writing unit 1 is not rotated but slid vertically.

  The printer 100 according to the present embodiment has a configuration in which one optical writing unit 1 is arranged above the four process units 2 (Y, M, C, K). As shown in FIG. The configuration may include a writing unit 1 (Y, M, C, K).

As described above, the printer 100 as the image forming apparatus of the present embodiment includes the photosensitive member 21 that is a latent image carrier that carries a latent image on the surface and moves, and the surface of the photosensitive member 21 by developing the latent image with toner. A latent image carrier unit detachably attached to the main body of the printer 100. The latent image carrier unit includes a developing device 22 as a developing unit for forming a toner image on the printer 100, and integrally supports a plurality of members including at least the photosensitive member 21. With respect to the installation space between the left wall 110L and the right wall 110R, which are two main body walls that form the process unit 2 and form the casings at both ends in the axial direction of the rotation axis of the photoconductor 21 of the printer 100 main body. Then, the process unit 2 is attached to or detached from the printer 100 main body by inserting or withdrawing the process unit 2 in the vertical direction that is perpendicular to the axial direction, and the process unit 2 is pushed. While wearing the printer 100 body, an image forming apparatus for transmitting drive from the drive motor 16 is a driving source of the printer 100 main body side with respect to the drive unit in the process unit 2. The printer 100 also includes a unit support member 11 that is a latent image carrier unit support member that supports the process unit 2 inserted in a downward direction orthogonal to the axial direction with respect to the installation space, and the unit support member 11 in the axial direction. A support member slide mechanism (not shown) that is a support member moving mechanism that is moved along the left and right side walls 110L, and the drive is transmitted to the photosensitive member 21, the developing roller 226, and the like that are drive units in the process unit 2. A drive transmission unit. In the printer 100, when the process unit 2 is inserted into the installation space, the drive unit and the drive transmission unit are separated from each other, and the unit support member 11 is moved to the drive transmission unit side together with the process unit 2 by the support member slide mechanism. By moving, the driven side coupling of the process unit 2 and the driving side coupling of the printer 100 main body side are connected, and the driving unit and the driving transmission unit are drivingly connected.
In the configuration described with reference to FIG. 13, the process cartridge is attached / detached in a direction perpendicular to the photosensitive member axis, thereby providing an attachable / detachable structure with excellent process cartridge attaching / detaching operability. However, the configuration shown in FIG. 13 has a problem that the width of the apparatus becomes large in order to secure the positioning of the process cartridge and the movement path of the drive coupling shape.
On the other hand, in the printer 100 of the present embodiment, positioning in the direction orthogonal to the axial direction by insertion of the process unit 2 and driving connection or positioning in the axial direction of the process unit 2 can be realized at different timings. In addition, it is not necessary to provide a space for the track through which the drive coupling or the secondary positioning shape passes or a special mechanism. For this reason, it is possible to realize an image forming apparatus having an inexpensive configuration, a small width, and excellent operability of the process cartridge that is frequently replaced.

  The exterior of the main body of the printer 100 includes a top cover 12 that is an openable and closable member on the upper surface of the apparatus in a direction orthogonal to the axial direction, and is a latent image writing device that writes a latent image on the surface of the uniformly charged photoreceptor 21. A certain optical writing unit 1 moves integrally with the upper cover 12 and opens the upper cover 12 to expose the installation space, so that the process unit 2 can be attached to and detached from the printer 100 main body. . The configuration in which the installation space of the process unit 2 is exposed by moving the optical writing unit 1 as in the printer 100 is such that the process is performed in an upward direction perpendicular to the axial direction of the photosensitive member 21 with the upper cover 12 opened. Since the unit 2 can be detached, the operability when exchanging the process unit 2 is excellent. However, the configuration in which the optical writing unit 1 is moved together with the upper cover 12 to expose the installation space is a configuration in which the photosensitive member 21 is disposed in the insertion direction in the process unit 2 as shown in FIG. When the photoconductor 21 is on the back side in the insertion direction, and a positioning member (positioning portion 211L in FIG. 13) on the axis of the rotation axis of the photoconductor 21 protrudes outward in the axial direction of the process unit 2, The problem that the space that becomes the track of the positioning member becomes a blank space becomes significant. With respect to such a problem, in the printer 100 of the present embodiment, the positioning member on the axis of the rotation axis of the photosensitive member 21 does not protrude outward in the axial direction of the process unit 2, and the space serving as the track of this member Therefore, it is possible to realize a configuration with excellent operability when replacing the process unit 2 while maintaining the downsizing of the image forming apparatus.

  Further, the support member slide mechanism provided in the printer 100 is an interlocking mechanism that moves the unit support member 11 toward the drive transmission unit (in the direction of arrow I in FIG. 8) in conjunction with the operation of closing the upper cover 12 that is an opening / closing member. Prepare. As a result, the unit support member 11 is moved in the direction in which the drive connection is possible in the direction of the photosensitive member axis in conjunction with the closing operation of the upper cover 12, so that the drive connection or process without a special mechanism such as an actuator is performed. The unit 2 can be positioned in the axial direction. Using a dedicated actuator for regulating and moving the unit support member 11 leads to an increase in apparatus size and cost, but the printer 100 of this embodiment does not require an actuator, so the printer 100 After insertion, a configuration for sliding in the axial direction can be realized at low cost.

  The printer 100 includes a plurality of process units 2, and the unit support member 11 is a unit left end support member 11 </ b> L and a unit right end support that are two end support members that respectively support the axial ends of the process units 2. It consists of member 11R. The unit left end support member 11L and the unit right end support member 11R support the lower portion of the process unit 2 with the positioning recess 112 as described with reference to FIG. 5, and the process unit 2 is pressed from above. Positioning means for positioning the photosensitive member 21 with respect to the printer 100 main body in a direction orthogonal to the axial direction when the process unit 2 is mounted on the printer 100 main body is configured. Thereby, the photosensitive member 21 can be positioned with respect to the main body of the printer 100 in a direction orthogonal to the axial direction with a simple configuration.

  Further, in the printer 100, since the shape of the positioning recess 112, which is a part constituting the positioning means of the photosensitive member 21 of the unit support member 11, is the same shape as the unit left end support member 11L and the unit right end support member 11R, at least It is possible to ensure parallelism between the plurality of photoconductors 21. In the printer 100 including the plurality of photoconductors 21, the image misalignment between colors has a great influence on the quality deterioration. Therefore, it is very important to define the pitch between the photoconductors 21 and ensure parallelism. In the printer 100, the unit left end support member 11L that supports both ends of the photoconductor 21 in the axial direction and the shape of the portion of the unit right end support member 11R that forms the positioning recess 112 are the same. Can be ensured, and excellent image quality with little image shift between colors can be provided.

  In addition, since the unit left end support member 11L and the unit right end support member 11R included in the printer 100 are formed of a metal material, a positioning recess is used to ensure the above-described parallelism by a method such as shape formation using the same mold. This is advantageous for realizing a configuration in which the shape of the portion forming 112 is the same, and is excellent in low cost such as adding a grounding function using conductivity. Therefore, it is possible to achieve the parallelism between the photoconductors 21 with higher accuracy at a low cost.

  Further, in the printer 100, since the unit left end support member 11L and the unit right end support member 11R are the same component, the definition of the pitch at both ends in the axial direction of the process unit 2 can be realized with a minimum error. In addition, doubling the number of parts produced is advantageous for cost reduction. Therefore, it is possible to achieve the parallelism between the photoconductors 21 with higher accuracy at a low cost.

  In the printer 100, since the unit left end support member 11L and the unit right end support member 11R are connected by the front side connection member 13F and the rear side connection member 13R which are connection members, one of the two unit support members 11 is connected. By restricting and moving, both unit support members 11 can be handled as an integral structure. As described above, the positioning of the process unit 2 can be performed with high accuracy by using the positioning recesses 112 of the unit support members 11 at both ends in the axial direction. Further, since the unit support member 11 is slidable in the axial direction with respect to the printer 100 main body, the operation of attaching and detaching the process unit 2 is divided into an operation of inserting into the installation space and an operation of performing drive connection. be able to. Here, if the unit left end support member 11L and the unit right end support member 11R, which are the unit support members 11, are configured to be independently movable, it is necessary to provide a mechanism for individually regulating or moving the position. On the other hand, in the printer 100, since one of the unit left end support member 11L and the unit right end support member 11R can be regulated and moved so that both can be handled as an integral structure, a configuration capable of realizing positioning with high accuracy is provided. It can be realized at low cost.

  The printer 100 also includes a support member urging spring 19 that is a support member urging means that urges the unit support member 11 in a direction away from the drive transmission unit, which is a direction in which the drive connection of the process unit 2 is released. Since the unit support member 11 is urged in the direction in which the drive connection is released in the axial direction, the upper cover 12 is opened, and the drive connection is released in a state where nothing is performed (initial state). Can be realized without any special mechanism. Thereby, it is not necessary to use a dedicated actuator for regulation and movement of the unit support member 11, and it is possible to prevent an increase in apparatus size and cost.

  Further, the printer 100 includes a rotation direction positioning hole 1403 in the apparatus main body left side plate 14L of the main body wall on the side including the drive transmission unit, and faces the apparatus main body left side plate 14L in a state where the process unit 2 is mounted on the printer 100 main body. The process unit 2 has a rotational direction positioning convex portion 205 on the wall surface, and the rotational direction positioning hole 1403 and the rotational direction positioning convex portion 205 are fitted when the unit support member 11 moves to the drive transmission portion side. Therefore, positioning of the process unit 2 in the rotation direction of the rotation shaft of the photoconductor 21 can be achieved without adding special parts. Therefore, the positioning of the process unit 2 in the rotation direction can be realized at low cost with high accuracy, and an image forming apparatus excellent in low cost and space saving can be provided.

  In the printer 100, the positioning of the unit support member 11 in the direction perpendicular to the axial direction with respect to the main body of the printer 100 is performed by extending a plurality of holes provided in the unit support member 11 in the axial direction and extending in the axial direction. It is constituted by four support member guides 15 which are fixed to the apparatus main body left side plate 14L or the apparatus main body right side plate 14R which are the main body wall portions and which are support member moving guide pins penetrating through the holes of the unit support member 11. Is done. As shown in FIG. 10, the left end support member front guide 15LF is attached by adjusting the position of the left end support member front side guide 15LF of the four support member guides 15 relative to the apparatus main body left side plate 14L. By adjusting the position, the position of the unit support member 11 with respect to the main body of the printer 100 can be adjusted, and the image misregistration between colors can be reduced. In order to achieve image quality with fewer image shifts between colors, it is desirable to have a configuration that can be adjusted according to individual assembly conditions. In addition, we want to improve the low cost by not depending on the component accuracy. For this reason, even an inexpensive unit support member 11 having a certain degree of error in component accuracy can be used by adjusting.

DESCRIPTION OF SYMBOLS 1 Optical writing unit 2 Process unit 3 Transfer unit 4 Registration roller pair 5 Paper feed roller 6 Paper feed cassette 7 Fixing device 7a Fixing roller 7b Pressure roller 8 Paper discharge roller pair 9 Stack part 11 Unit support member 11L Unit left end support member 11R unit right end support member 12 upper cover 13F front side connection member 13R rear side connection member 14L device main body left side plate 14R device main body right side plate 15 support member guide 15L left end support member guide 15LF left end support member front side guide 15LR left end support member rear side guide 15R Right end support member guide 15RF Right end support member front guide 15RR Right end support member rear guide 16 Drive motor 17 First gear 17G Drive transmission gear 18 Second gear 19 Support member biasing spring 20 Drive side coupling slide mechanism 20a First drive side Couplin 20b Second drive side coupling 21 Photoconductor 21a Photoconductor driven side coupling 21G Drive gear 22 Developing device 22a Development driven side coupling 23 Charging device 24 Drum cleaning device 31 Intermediate transfer belt 32 Primary transfer roller 33 Drive roller 34 Secondary Transfer roller 35 Drive roller 40 Reverse unit 40a Rotating shaft 41 Pre-reversal transport path 43 Reverse transport roller pair 44 Reverse transport path 45 Front cover 46 Oscillator 51 Paper feed path 52 Post-transfer transport path 53 Post-fixation transport path 54 Paper discharge path 55 Pre-reverse transport path 60 Bracket member 61 Shaft member 91 Unit upper surface pressing member 92 Unit upper surface pressing spring 93 Lever member 100 Printer 110L Left side wall portion 110R Right side wall portion 112 Positioning recess 115L Left side fixing member 205 Rotational direction positioning convex portion 211L Positioning portion 221 Hopper Part 222 agitator 223 developing part 224 communication hole 225 stirring paddle 226 developing roller 227 toner supply roller 228 thinning blade 1401 first side plate opening 1402 second side plate opening 1403 rotation direction positioning hole 1404 opening

JP 2008-165023 A JP 2006-154746 A JP 2007-140041 A

Claims (11)

A plurality of members including at least a latent image carrier are integrally supported, and a latent image carrier unit that can be attached to and detached from the apparatus main body is provided.
The latent image carrier unit in a direction orthogonal to the axial direction with respect to an installation space between two main body wall portions that form a casing at both ends in the axial direction of the rotation axis of the latent image carrier of the apparatus main body The latent image carrier unit is attached to and detached from the apparatus main body by inserting or withdrawing,
In an image forming apparatus that transmits drive from a drive source on the apparatus body side to a drive unit in the latent image carrier unit in a state where the latent image carrier unit is mounted on the apparatus body.
A latent image carrier unit support member that supports the latent image carrier unit inserted in a direction orthogonal to the axial direction with respect to the installation space;
A support member moving mechanism for moving the latent image carrier unit support member along the axial direction;
A drive transmission portion disposed on one of the two main body wall portions and transmitting drive to the drive portion in the latent image carrier unit;
In the state where the latent image carrier unit is inserted into the installation space, the drive unit and the drive transmission unit are separated from each other, and the latent image carrier unit is moved together with the latent image carrier unit by the support member moving mechanism. An image forming apparatus, wherein the drive unit and the drive transmission unit are drivingly connected by moving a support member to the drive transmission unit side. The image forming apparatus according to claim 1.
The exterior of the apparatus main body includes an opening / closing member that can be opened and closed on the apparatus side surface or the apparatus upper surface in a direction orthogonal to the axial direction,
The latent image writing apparatus for writing a latent image on the surface of the uniformly charged latent image carrier moves integrally with the opening / closing member and opens the opening / closing member to expose the installation space. An image forming apparatus, wherein the latent image carrier unit can be attached to and detached from the apparatus main body. The image forming apparatus according to claim 2.
The image forming apparatus, wherein the support member moving mechanism includes an interlocking mechanism that moves the latent image carrier unit support member to the drive transmission unit side in conjunction with an operation of closing the opening / closing member. The image forming apparatus according to any one of claims 1 to 3,
Having a plurality of latent image carrier units,
The latent image carrier unit support member includes two end support members that respectively support the axial ends of the plurality of latent image carrier units.
The end support member constitutes positioning means for positioning the latent image carrier with respect to the apparatus main body in a direction orthogonal to the axial direction when the latent image carrier unit is mounted on the apparatus main body. An image forming apparatus. The image forming apparatus according to claim 4.
2. An image forming apparatus according to claim 1, wherein the end support member has the same shape as that of the positioning means of the latent image carrier. The image forming apparatus according to claim 4 or 5,
2. The image forming apparatus according to claim 2, wherein the two end support members are made of a metal material. The image forming apparatus according to any one of claims 4 to 6,
The image forming apparatus, wherein the two end support members are the same part. The image forming apparatus according to any one of claims 4 to 7,
An image forming apparatus, wherein the two end support members are integrally connected by a connecting member. The image forming apparatus according to any one of claims 1 to 8,
An image forming apparatus comprising: a support member urging unit that urges the latent image carrier unit support member in a direction away from the drive transmission unit. The image forming apparatus according to any one of claims 1 to 9,
Each of the main body wall on the side including the drive transmission unit and the wall surface of the latent image carrier unit facing the main body wall in a state where the latent image carrier unit is mounted on the apparatus main body,
An image forming apparatus comprising: a fitting shape that fits when the latent image carrier unit support member moves toward the drive transmission unit. The image forming apparatus according to any one of claims 1 to 10,
The positioning of the latent image carrier unit support member in the direction orthogonal to the axial direction with respect to the apparatus main body is performed by a plurality of holes provided in the latent image carrier unit support member so as to penetrate in the axial direction, A support member moving guide pin that is fixed to the body wall portion so as to extend in the direction and penetrates the hole portion;
An image forming apparatus, wherein a position of at least one of the support member moving guide pins with respect to the main body wall is adjustable.

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