WO2014080808A1

WO2014080808A1 - Image forming device

Info

Publication number: WO2014080808A1
Application number: PCT/JP2013/080623
Authority: WO
Inventors: 仲野久仁昭; 栗本直彰
Original assignee: シャープ株式会社
Priority date: 2012-11-26
Filing date: 2013-11-13
Publication date: 2014-05-30
Also published as: JP2014123102A; JP5738953B2

Abstract

An image forming device comprises a device main body (110), and a unit assembly (10). The unit assembly body (10) further comprises an image forming unit (20) and an intermediate transfer unit (40). When the unit assembly (10) is inserted into the device main body (110), processing unit transmission parts (205A-205D, 310A-310D) are respectively connected to processing unit driving parts, and an intermediate transfer unit transmission part (49) is connected to an intermediate transfer unit driving part.

Description

Image forming apparatus

The present invention relates to an image forming apparatus that employs an intermediate transfer system that transfers a developer image onto a sheet via an intermediate transfer unit.

A tandem type image forming apparatus adopting an intermediate transfer system includes a process unit including a photosensitive drum, a developing unit including a developer carrier, a processing unit such as an exposure unit including an exposure member, and an intermediate including an intermediate transfer roller. A transfer unit is provided. When these units are separately mounted on the main body of the image forming apparatus, a space is provided between the developing unit or intermediate transfer unit and the photosensitive drum so as not to damage the photosensitive drum when inserted into the main body. It is necessary to provide. For this reason, the accuracy of the relative position between the units is lowered, and there is a possibility that the image quality is lowered due to the color shift.

Therefore, there is known an image forming apparatus including a unit aggregate formed by connecting a plurality of processing units to a tray (for example, see Patent Document 1). In this conventional image forming apparatus, a plurality of processing units are integrally inserted into and removed from the apparatus main body as a unit aggregate. On the other hand, the intermediate transfer unit is fixed to the apparatus main body.

JP-A-9-304994

However, in the conventional image forming apparatus, no consideration is given to the positioning between the processing unit and the intermediate transfer unit. For this reason, the positional accuracy between the processing unit and the intermediate transfer unit may be lowered. If the positional accuracy between the plurality of processing units and the intermediate transfer unit is low, image misregistration occurs, and color misregistration occurs in the full-color image forming apparatus, resulting in degradation of image quality.

Further, Patent Document 1 does not describe any supply of driving force to the processing unit. For this reason, in a conventional image forming apparatus, it is unclear how a plurality of processing units configured to be detachable with respect to the apparatus main body obtain driving force. Further, in the conventional image forming apparatus, it is not clear about the supply of driving force to the intermediate transfer unit when the intermediate transfer unit is configured to be detachable from the apparatus main body. Therefore, in the conventional image forming apparatus, when inserting into the apparatus main body, an operation for supplying driving force to a plurality of processing units and an intermediate transfer unit when configured to be detachable from the apparatus main body. There is a risk that it will be worse.

An object of the present invention is to improve the positional accuracy between a plurality of processing units and the positional accuracy between a plurality of processing units and an intermediate transfer unit, and to supply driving force to the plurality of processing units and the intermediate transfer unit. An object of the present invention is to provide an image forming apparatus capable of improving workability.

The image forming apparatus of the present invention performs an electrophotographic image forming process. The image forming apparatus includes an apparatus main body and a unit assembly configured to be detachable from the apparatus main body. The unit assembly includes a plurality of processing units and an image forming unit having a connecting member that connects the plurality of processing units in a state of relative positioning with each other, and a development formed using the plurality of processing units. An intermediate transfer unit that carries an agent image and conveys it to a transfer position on a sheet, and is held in a state of being positioned at a predetermined position by the image forming unit. The apparatus main body includes a plurality of processing unit driving units that supply driving force for driving the plurality of processing units, and an intermediate transfer unit driving unit that supplies driving force for driving the intermediate transfer unit. Each of the plurality of processing units has a processing unit transmission unit that receives a driving force from the processing unit driving unit. The intermediate transfer unit includes an intermediate transfer unit transmission unit that receives a driving force from the intermediate transfer unit drive unit. When the unit aggregate is inserted into the apparatus main body, the processing unit transmission unit is connected to the processing unit driving unit, and the intermediate transfer unit transmission unit is connected to the intermediate transfer unit driving unit.

In this configuration, a plurality of processing units are connected and fixed and integrated to form an image forming unit, and an intermediate transfer unit is held by the image forming unit to form a unit assembly. A plurality of processing units and intermediate transfer units are integrated outside the apparatus main body, and are inserted into and removed from the apparatus main body as a unit assembly, thus preventing damage during assembly between the processing unit and the intermediate transfer unit. It is not necessary to provide a space, and the accuracy of the relative position between the units in the apparatus main body can be improved as compared with the case where the units are individually inserted and removed. For this reason, the positional accuracy between processing unit transmission parts can be improved. Further, it can be miniaturized by space saving. Further, since the intermediate transfer unit is held in the image forming unit in a positioned state, the positional accuracy between the plurality of processing units and the intermediate transfer unit can be further improved. For this reason, the positional accuracy between the plurality of processing unit transmission units and the intermediate transfer unit transmission unit can be improved. Accordingly, when at least one of the plurality of processing unit transmission units and the intermediate transfer unit transmission unit is aligned with the corresponding driving unit among the plurality of processing unit driving units and the intermediate transfer unit driving unit, another transmission is performed. The part can also be easily and accurately aligned with the corresponding driving part. Therefore, when inserting the unit assembly into the apparatus main body, the processing unit transmission unit can be easily connected to the processing unit driving unit, and the intermediate transfer unit transmission unit can be easily connected to the intermediate transfer unit driving unit. The processing unit and the intermediate transfer unit can be driven smoothly.

The image forming apparatus of the present invention performs an electrophotographic image forming process. The image forming apparatus includes an apparatus main body and a unit assembly configured to be detachable from the apparatus main body. The unit assembly includes an image forming unit having a processing unit, and an intermediate transfer unit that carries a developer image formed by using the processing unit and conveys the developer image to a transfer position on a sheet. The apparatus main body includes a processing unit driving unit that supplies a driving force for driving the processing unit, and an intermediate transfer unit driving unit that supplies a driving force for driving the intermediate transfer unit. The processing unit includes a processing unit transmission unit that receives a driving force from the processing unit driving unit. The intermediate transfer unit includes an intermediate transfer unit transmission unit that receives a driving force from the intermediate transfer unit drive unit. When the unit assembly is inserted into the apparatus main body, the processing unit transmission unit is connected to the processing unit driving unit, and the intermediate transfer unit transmission unit is connected to the intermediate transfer unit driving unit.

In this configuration, a unit assembly is configured by holding the intermediate transfer unit in an image forming unit having a single processing unit. A single processing unit and intermediate transfer unit are integrated outside the main body of the apparatus, and are inserted into and removed from the main body of the apparatus as a unit assembly, thus preventing damage during assembly between the processing unit and the intermediate transfer unit. Therefore, it is possible to improve the accuracy of the relative position between the units in the apparatus main body as compared with the case where the units are individually inserted and removed. Further, it can be miniaturized by space saving. Further, since the intermediate transfer unit is held in the image forming unit, the positional accuracy between the single processing unit and the intermediate transfer unit can be further improved. For this reason, the positional accuracy between the single processing unit transmission unit and the intermediate transfer unit transmission unit can be improved. Accordingly, when at least one of the single processing unit transmission unit and the intermediate transfer unit transmission unit is aligned with the corresponding driving unit of the single processing unit driving unit and the intermediate transfer unit driving unit, It is possible to easily and accurately align the transmission portion with the corresponding drive portion. Therefore, when the unit assembly is inserted into the apparatus main body, the processing unit transmission unit can be easily connected to the processing unit drive unit, and the intermediate transfer unit transmission unit can be easily connected to the intermediate transfer unit drive unit. The processing unit and the intermediate transfer unit can be driven smoothly.

According to the present invention, the positional accuracy between the plurality of processing units and the positional accuracy between the plurality of processing units and the intermediate transfer unit can be improved, and driving force can be supplied to the plurality of processing units and the intermediate transfer unit. Workability can be improved.

1 is a front sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. It is an external appearance perspective view which shows the state which the unit assembly detach | leaved with respect to the apparatus main body. (A)-(D) are figures which show the member with which a unit assembly is equipped. It is a perspective view from the right diagonal side of the developing unit showing an extension part included in the positioning part. It is a perspective view from the diagonally left side of the developing unit showing a receiving part included in the positioning part. It is a front view of a process unit and a developing unit. FIG. 6 is a front view showing a state in which a plurality of process units are respectively held by a plurality of developing units and the plurality of developing units are positioned relative to each other. It is a front view of an image forming unit. It is a front view of a unit aggregate. It is a figure which shows schematic structure of a 2nd positioning part. It is a rear view of a unit aggregate. It is the front view which expanded a part of apparatus main body. FIG. 4 is a perspective view illustrating a part of an intermediate transfer unit driving unit and an intermediate transfer unit transmission unit. FIG. 10 is a front view of a unit assembly provided in an image forming apparatus according to a second embodiment. FIG. 10 is an external perspective view illustrating a state where a unit assembly is detached from an apparatus main body of an image forming apparatus according to a third embodiment.

The image forming apparatus 100 according to the first embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the image forming apparatus 100 includes an apparatus main body 110 and an automatic document feeder (ADF: Automatic Document Feeder) 120. The image forming apparatus 100 forms a multicolor or single color image on a sheet based on image data generated from a document or image data input from the outside. Examples of paper include sheet-like recording media such as plain paper, photographic paper, and OHP film.

The ADF 120 is disposed on the apparatus main body 110.

The apparatus main body 110 includes an image reading unit 130, an image forming unit 140, and a paper feeding unit 150.

The image reading unit 130 is arranged on the upper part of the apparatus main body 110, reads an image of a fixedly arranged document in the fixed document reading mode, generates image data, and is transported one by one by the ADF 120 in the transported document reading mode. The image of the original is read to generate image data.

The image forming unit 140 includes an optical scanning device 3, four

image forming stations

30A, 30B, 30C, and 30D, an intermediate transfer unit 40, a secondary transfer unit 50, and a fixing device 70, and an electrophotographic image on a sheet. A forming process is performed.

The intermediate transfer unit 40 includes an intermediate transfer belt 41, a driving roller 42, a driven roller 43, and a tension roller 44. The intermediate transfer belt 41 is stretched by a driving roller 42, a driven roller 43, and a tension roller 44 to form a loop-shaped movement path.

The image forming unit 140 supplies toner images (developer images) of black and four hues of cyan, magenta, and yellow, which are three subtractive primary colors obtained by color separation of a color image, to an image forming station. 30A to 30D are formed. The image forming stations 30A to 30D are arranged in a line along the movement path of the intermediate transfer belt 41. The image forming stations 30B to 30D are configured substantially in the same manner as the image forming station 30A.

The black image forming station 30A includes a photosensitive drum 1A, a charger 2A, a developing unit 4A, a primary transfer roller 5A, and a cleaning unit 6A.

The photosensitive drum 1A is rotated in a predetermined direction by transmitting a driving force. The charger 2A charges the peripheral surface of the photosensitive drum 1A to a predetermined potential.

The optical scanning device 3 irradiates the respective

photosensitive drums

1A, 1B, 1C, and 1D of the image forming stations 30A to 30D with laser beams modulated by the image data of black, cyan, magenta, and yellow hues, respectively. To do. Electrostatic latent images based on image data of each hue of black, cyan, magenta, and yellow are formed on the peripheral surfaces of the photosensitive drums 1A to 1D, respectively.

The developing unit 4A supplies black toner (developer) which is the hue of the image forming station 30A to the peripheral surface of the photosensitive drum 1A, and visualizes the electrostatic latent image into a toner image. Similarly, the developing

units

4B, 4C, and 4D of the image forming stations 30B to 30D supply toners of the respective hues to the peripheral surfaces of the photosensitive drums 1B to 1D.

The outer peripheral surface of the intermediate transfer belt 41 sequentially faces the peripheral surfaces of the photosensitive drums 1A to 1D. A primary transfer roller 5A is disposed at a position facing the photosensitive drum 1A with the intermediate transfer belt 41 interposed therebetween. Each of the positions where the intermediate transfer belt 41 and the photosensitive drums 1A to 1D face each other is a primary transfer position.

The primary transfer bias is applied to the primary transfer roller 5A by constant voltage control with a primary transfer bias of the toner charged polarity (for example, minus) and opposite polarity (for example, plus). The same applies to the image forming stations 30B to 30D. As a result, the toner images of the respective hues formed on the respective peripheral surfaces of the photosensitive drums 1A to 1D are primarily transferred onto the outer peripheral surface of the intermediate transfer belt 41 so as to be sequentially transferred onto the outer peripheral surface of the intermediate transfer belt 41. An image is formed.

However, when image data of only a part of the hues of black, cyan, magenta, and yellow is input, only part of the four photosensitive drums 1A to 1D corresponding to the hue of the input image data. Then, an electrostatic latent image and a toner image are formed, and only a partial toner image is primarily transferred onto the outer peripheral surface of the intermediate transfer belt 41.

The cleaning unit 6A collects toner remaining on the peripheral surface of the photosensitive drum 1A after development and primary transfer.

The toner image primarily transferred to the outer peripheral surface of the intermediate transfer belt 41 at each primary transfer position is rotated by the intermediate transfer belt 41 and the secondary transfer roller 51 provided in the intermediate transfer belt 41 and the secondary transfer unit 50. Are conveyed to the secondary transfer position, which is the opposite position.

The paper feed unit 150 includes a paper feed cassette 151, a manual feed tray 152, and a paper transport path 61. As necessary, paper is selectively supplied to the paper transport path 61 from either the paper feed cassette 151 or the manual feed tray 152.

The paper transport path 61 is formed so as to reach the paper discharge tray 62 from the paper feed cassette 151 and the manual feed tray 152 through the secondary transfer position and the fixing device 70, respectively.

The secondary transfer roller 51 is in pressure contact with the driving roller 42 with a predetermined nip pressure across the intermediate transfer belt 41.

When the sheet fed from the sheet feeding unit 150 passes through the secondary transfer position, the secondary transfer bias is applied to the secondary transfer roller 51 with the toner charging polarity (for example, minus) and the opposite polarity (for example, plus). Is applied by constant voltage control, whereby the toner image carried on the outer peripheral surface of the intermediate transfer belt 41 is secondarily transferred to the paper.

The toner remaining on the intermediate transfer belt 41 after the toner image is transferred to the paper is collected by the intermediate transfer belt cleaning device 45.

The sheet on which the toner image is transferred is guided to the fixing device 70. The fixing device 70 includes a heating roller 71 and a pressure roller 72, and heats and presses the paper passing between the heating roller 71 and the pressure roller 72 to fix the toner image on the paper. The sheet on which the toner image is fixed is discharged onto the discharge tray 62 with the surface on which the toner image is fixed facing down.

One type or a plurality of types of image forming members that are members for forming a toner image are each unitized as a processing unit. One or more types of processing units and the intermediate transfer unit 40 are included in the unit assembly 10. Examples of the image forming member include the photosensitive drums 1A to 1D, the charger 2A, the developing roller, the primary transfer roller 5A, and the cleaning unit 6A. The developing roller is a developer carrier.

As shown in FIG. 2, the apparatus main body 110 has an insertion portion 110A that opens to the front surface. The unit assembly 10 is configured to be detachable with respect to the insertion portion 110A of the apparatus main body 110 in a predetermined third direction 93 parallel to the rotation axis of the photosensitive drum 1A. The third direction 93 is a direction parallel to the insertion / removal direction of the unit assembly 10 with respect to the apparatus main body 110.

As shown in FIGS. 3A to 3D, as an example, the unit assembly 10 includes an intermediate transfer unit 40, two connecting members 80, a plurality of

process units

200A, 200B, 200C, 200D, and A plurality of developing

units

4A, 4B, 4C, and 4D are provided. The process units 200A to 200D include the photosensitive drums 1A to 1D, respectively, and correspond to the first processing unit. The developing units 4A to 4D each include a developing roller and correspond to a second processing unit. 3, FIG. 7 to FIG. 9, FIG. 11, and FIG. 14 schematically show the process units 200A to 200D and the developing units 4A to 4D.

The intermediate transfer unit 40 further includes an intermediate transfer unit frame 46, and the driving roller 42 and the driven roller 43 are pivotally supported by the intermediate transfer unit frame 46. The intermediate transfer unit 40 has a plurality of

protrusions

47A and 47B at predetermined positions of the front and back intermediate transfer unit frames 46, respectively. The plurality of

protrusions

47A and 47B protrude in the horizontal direction and are arranged at different positions in the traveling direction of the intermediate transfer belt 41.

The connecting member 80 has a plate shape. Each of the connecting members 80 has a plurality of

recesses

81A and 81B at positions corresponding to the plurality of

protrusions

47A and 47B. Each of the connecting members 80 has a plurality of through

holes

82A, 82B, 82C, 83A, 83B, 83C, 83D.

4 to 6 show a configuration of the developing unit 4B arranged at a place other than both ends in the arrangement direction of the developing units 4A to 4D. The developing unit 4C disposed at a location other than the other ends of the developing unit 4B is configured in the same manner as the developing unit 4B. The developing unit 4A arranged at one end is configured in the same manner as the developing unit 4B except that it does not have an extending part, and the developing unit 4D arranged at the other end does not have a receiving part. Except for this point, the configuration is the same as that of the developing unit 4B.

As shown in FIGS. 4 to 6, the developing unit 4B is preferably configured such that the position of the center of gravity in the cross section orthogonal to the third direction 93 is located below the center in the height direction. As an example, the developing unit 4B is configured such that the dimension in the horizontal direction increases toward the bottom in a cross section orthogonal to the third direction. As another example, the developing unit 4B can be configured such that the cross-sectional shape orthogonal to the third direction is a substantially triangular shape or a substantially trapezoidal shape.

Thereby, when the developing unit 4B is placed on the work table and the process unit 200B is held by the developing unit 4B, the stability of the developing unit 4B is increased, so that workability is improved.

Here, three directions orthogonal to each other are defined as a first direction 91, a second direction 92, and a third direction 93. The first direction 91 is the same as the arrangement direction of the developing units 4A to 4D. The second direction 92 is a direction orthogonal to a region of the intermediate transfer belt 41 facing an image forming unit 20 (see FIG. 8) described later. The third direction 93 is the insertion / removal direction of the unit assembly 10 with respect to the apparatus main body 110 as described above.

The developing unit 4B has a third positioning portion. The third positioning part includes extending

parts

301B and 302B and receiving parts 303B and 304B (however, the receiving part 304B is not shown). The extending portions 301 B and 302 B are provided at the first end of the developing unit 4 B in the first direction 91 and at both ends of the developing unit 4 B in the third direction 93. The receiving portions 303 B and 304 B are provided at the second end of the developing unit 4 B in the first direction 91 and at both ends of the developing unit 4 B in the third direction 93.

In the developing unit 4B, the extending

portions

301B and 302B extend in a first direction 91 by a predetermined length from the first end of the developing unit 4B toward the developing unit 4A adjacent to the first end. Yes.

The receiving portions 303B and 304B are configured to receive the extending portions 301C and 302C of the developing unit 4C adjacent to the second end of the developing unit 4B (however, the extending portion 302C is not shown). Yes.

The receiving portions 303B and 304B are configured to restrict movement of the extending portions 301C and 302C of the developing unit 4C adjacent to the receiving portions 303B and 304B in at least the first direction 91, respectively.

The receiving unit 304B is configured similarly to the receiving unit 303B. As an example, the receiving portion 303B includes a first protruding portion 303B1 and a second protruding portion 303B2 that sandwich the extending portion 301C of the developing unit 4C adjacent to the receiving portions 303B and 304B in the third direction 93.

By sandwiching the extended portion 301C of the developing unit 4C between the first protruding portion 303B1 and the second protruding portion 303B2 of the developing unit 4B, the first protruding portion 303B1 and the second protruding portion 303B2 are connected to the extended portion 301C. The movement in both directions in the three directions 93 is restricted. For this reason, the position of the developing unit 4C in the third direction 93 with respect to the developing unit 4B is accurately defined. Accordingly, when the plurality of developing units 4A to 4D are relatively positioned with respect to each other, the positional accuracy in the third direction 93 between the plurality of developing units 4A to 4D can be improved.

The extending part 301B has a bearing part 305B extending in the third direction 93 in the vicinity of the tip part. The extending portion 302B has a bearing portion 306B extending in the third direction 93 in the vicinity of the distal end portion.

The process unit 200B has a shaft portion 201B extending in the third direction 93 at the bottom. Shaft portion 201B is rotatably received by bearing

portions

305B and 306B.

The process unit 200B rotates in a state where the shaft portion 201B is supported by the bearing

portions

305B and 306B, so that the predetermined first contact portion 202B separated from the shaft portion 201B becomes the predetermined second contact of the developing unit 4B. It is comprised so that it may contact | abut to the part 307B. The second contact portion 307B has a shape along the outer shape of the first contact portion 202B.

The shaft portion 201B of the process unit 200B is supported by the bearing

portions

305B and 306B of the development unit 4B with a space between the first contact portion 202B of the process unit 200B and the second contact portion 307B of the development unit 4B. In this state, the process unit 200B is rotated around the shaft portion 201B. Thereby, the process unit 200B and the developing unit 4B are divided into two regions, a contact region between the shaft portion 201B and the bearing

portions

305B and 306B, and a contact region between the first contact portion 202B and the second contact portion 307B. While being able to position, the damage at the time of the assembly operation of the process unit 200B and the developing unit 4B can be suppressed.

Further, the bearing

portions

305B and 306B are provided in the extending

portions

301B and 302B, so that the distance between the shaft portion 201B and the first contact portion 202B and the distance between the bearing

portions

305B and 306B and the second contact portion 307B. Therefore, the positional accuracy between the process unit 200B and the developing unit 4B can be improved.

The developing unit 4B has

buffer members

308B and 309B at the second contact portion 307B. Thereby, the process unit 200B and the developing unit 4B can be further prevented from being damaged.

As described above, by holding the process units 200A to 200D in the developing units 4A to 4D and positioning the developing units 4A to 4D relative to each other, as shown in FIG. The process units 200A to 200D and the plurality of development units 4A to 4D are accurately positioned. Note that the work order of holding the process units 200A to 200D in the developing units 4A to 4D and positioning the developing units 4A to 4D relative to each other can be performed first. .

As shown in FIG. 8, the plurality of process units 200A to 200D are held by the plurality of development units 4A to 4D, respectively, and the plurality of development units 4A to 4D are positioned relative to each other. Thus, the plurality of developing units 4A to 4D are connected by the connecting member 80. In FIG. 8, the connecting member 80 is hatched for convenience of explanation.

The connecting member 80 is disposed on the front side and the back side so as to face each other across the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D.

The connecting member 80 is screwed into the screw holes of the plurality of developing units 4A to 4D through the through holes 83A to 83D provided at positions corresponding to the screw holes provided in the developing units 4A to 4D. Is done. Accordingly, the relative positions of the plurality of developing units 4A to 4D are fixed by the connecting member 80.

The through holes 82A to 82C and 83A to 83D of the connecting member 80 are preferably long holes. Since the through holes 82A to 82C and 83A to 83D are elongated holes in the first direction 91 or the second direction 92, the relative positions of the developing units 4A to 4D can be finely adjusted. It becomes possible.

Further, the process units 200A to 200D are supported by the connecting member 80 on the front side. The structure of the connecting member 80 on the back side and the process units 200A to 200D will be described later.

As described above, the image forming unit 20 is configured by connecting and fixing the plurality of developing units 4A to 4D holding the plurality of process units 200A to 200D.

As shown in FIG. 9, the unit assembly 10 is configured by holding the intermediate transfer unit 40 in the image forming unit 20. In FIG. 9, for convenience of explanation, the connecting member 80 and the intermediate transfer unit frame 46 are hatched.

When the intermediate transfer unit 40 is assembled to the connecting member 80 from above, the projection 47A and the recess 81A are fitted and the projection 47B and the recess 81B are fitted on the front side and the back side, respectively. The intermediate transfer unit 40 is accurately positioned with respect to the connecting member 80. The protrusion 47A and the recess 81A, and the protrusion 47B and the recess 81B constitute

first positioning portions

611 and 612 that perform relative positioning of the intermediate transfer unit 40 and the connecting member 80, respectively.

The intermediate transfer unit 40 is screwed into the screw holes of the intermediate transfer unit 40 through the through holes 82A to 82C of the connection member 80 in a state where the intermediate transfer unit 40 is accurately positioned with respect to the connection member 80 on each of the front side and the back side. . As a result, the intermediate transfer unit 40 is fixed in a state where it is accurately positioned with respect to the connecting member 80 on the front side and the back side.

Since the intermediate transfer unit 40 is fixed to each of the connecting members 80 that face each other across the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D, the connecting member 80 and the intermediate transfer unit 40 have a plurality of processes. The unit 200A to 200D and the plurality of development units 4A to 4D are fixed in a state of being arranged in a U-shaped cross section so as to surround the three surfaces. Therefore, the intermediate transfer unit 40 can function as a reinforcing member for the image forming unit 20.

Further, since the intermediate transfer unit 40 is disposed on the connecting member 80, the unit assembly 10 can be assembled more easily.

FIG. 10 is a schematic view of the primary transfer roller 5A and the photosensitive drum 1A viewed from the right side. As shown in FIG. 10, the intermediate transfer unit 40 has

third contact portions

481A and 482A on the front side and the back side of the primary transfer roller 5A. Further, the process unit 200A has

fourth contact portions

203A and 204A on the front side and the back side of the photosensitive drum 1A. When the intermediate transfer unit 40 is assembled to the connecting member 80 from above, the third contact portion 481A and the fourth contact portion 203A contact each other, and the third contact portion 482A and the fourth contact portion 204A contact each other. By contacting, the primary transfer roller 5A and the photosensitive drum 1A facing each other are positioned, and the relative positional accuracy between the primary transfer roller 5A and the photosensitive drum 1A is further improved. The

third contact portions

481A and 482A and the

fourth contact portions

203A and 204A constitute a second positioning portion 621.

The intermediate transfer unit 40 also has a third contact portion for the primary transfer rollers 5B to 5C, as in the case of the primary transfer roller 5A. The process units 200B to 200D have the fourth abutting portion, similar to the process unit 200A. Accordingly, the relative positional accuracy of the primary transfer rollers 5B to 5C and the photosensitive drums 1B to 1D facing each other is further improved. The third contact portion and the fourth contact portion that contact each other constitute

second positioning portions

622, 623, and 624, respectively.

In the connecting direction of the plurality of process units 200A to 200D, that is, the first direction 91, the

first positioning portions

611 and 612 are arranged between the second positioning portions 621 to 624. Specifically, in the first direction 91, the first positioning unit 611 is disposed between the second positioning unit 621 and the second positioning unit 622, and the first positioning unit 612 is connected to the second positioning unit 623 and the second positioning unit 622. 2 between the positioning portions 624.

Accordingly, the

first positioning portions

611 and 612 and the second positioning portions 621 to 624 are arranged so as to be more scattered, so that the relative positional accuracy between the intermediate transfer unit 40 and the connecting member 80, and The relative positional accuracy of the primary transfer rollers 5A to 5D and the photosensitive drums 1A to 1D facing each other can be further improved.

In the unit assembly 10, a plurality of process units 200A to 200D are held by a plurality of development units 4A to 4D, and a plurality of development units 4A to 4D are connected and fixed to form an image forming unit 20, and image formation is further performed. The unit assembly 10 is configured by the unit 20 holding the intermediate transfer unit 40.

Since the plurality of process units 200A to 200D, the plurality of developing units 4A to 4D, and the intermediate transfer unit 40 are integrated outside the apparatus main body 110 and inserted into and removed from the apparatus main body 110 as the unit assembly 10, each unit 200A. Compared to the case where the units 200A to 200D, 4A to 4D, and 40 are individually inserted / removed, there is no need to provide a space for preventing scratches during assembly between the 200D, 4A to 4D, and 40 The accuracy of the relative position between the units 200A to 200D, 4A to 4D, 40 in the main body 110 can be improved. Furthermore, the size can be reduced by space saving.

In addition, as described above, since the unit assembly 10 is inserted into and removed from the apparatus main body 110 in a state where the image forming unit 20 holds the intermediate transfer unit 40 outside the apparatus main body 110 to form the unit assembly 10, The positional accuracy between the forming unit 20 and the intermediate transfer unit 40 can also be improved. For this reason, it is possible to suppress the shift of the image transferred from the image forming unit 20 to the intermediate transfer unit 40, and to improve the image quality.

Furthermore, since the image forming unit 20 and the intermediate transfer unit 40 are integrated as the unit assembly 10, the handling becomes easy, the operability in work such as replacement, maintenance, and adjustment is good, and the working efficiency is improved. . Further, mistakes in insertion can be suppressed during insertion into the apparatus main body 110. This improves the workability for the user. Furthermore, since the positioning between the plurality of units 200A to 200D, 4A to 4D, 40 is performed outside the apparatus main body 110, it can be easily and accurately performed as compared with the case where it is performed within the apparatus main body 110. The workability of the assembly work of the image forming apparatus 100 can be improved.

As shown in FIG. 11, the rotation shafts of the photoconductive drums 1A to 1D are provided to the outside rather than the connecting member 80 on the back side, and the processing

unit transmission units

205A, 205B, 205C, and 205D are provided at the respective leading ends. Have. Similarly, the rotation shafts of the developing rollers of the developing units 4A to 4D are provided to the outside rather than the connecting member 80 on the back side, and the processing

unit transmission units

310A, 310B, 310C, and 310D are provided at the respective leading ends. Have.

Further, the rotation shaft of the driving roller 42 of the intermediate transfer unit 40 is provided to the outside rather than the connecting member 80 on the back side, and has an intermediate transfer unit transmission portion 49 at the tip thereof. In FIG. 11, the second positioning portions 621 to 624 are not shown.

As shown in FIG. 12, a processing unit drive is provided on the surface on the back side of the insertion portion 110 A of the apparatus main body 110, which faces the back surface of the unit assembly 10 when the unit assembly 10 is inserted.

Units

111, 112, 113, 114, 115, 116, 117, 118, and an intermediate transfer unit driving unit 119 are provided.

The processing unit driving units 111 to 118 are provided at positions facing the processing unit transmission units 205A to 205D and 310A to 310D, respectively, when the unit assembly 10 is inserted. The intermediate transfer unit drive unit 119 is provided at a position facing the intermediate transfer unit transmission unit 49 when the unit assembly 10 is inserted.

The processing unit driving units 111 to 118 and the intermediate transfer unit driving unit 119 are rotated by being supplied with a driving force from a driving source such as a motor (not shown) built in the apparatus main body 110, respectively.

The processing unit drive units 111 to 118 and the corresponding processing unit transmission units 205A to 205D and 310A to 310D each have a rotational force in a state where the unit assembly 10 is inserted into the insertion unit 110A of the apparatus main body 110. Connected for transmission. For example, the processing unit driving units 111 to 118 and the corresponding processing unit transmission units 205A to 205D and 310A to 310D are connected so as to be able to transmit the rotational force by fitting the protrusions and the recesses.

As shown in FIG. 13, the intermediate transfer unit drive unit 119 and the intermediate transfer unit transmission unit 49 are connected so that rotational force can be transmitted in a state where the unit assembly 10 is inserted into the insertion unit 110A.

The image forming apparatus 100 positions the intermediate transfer unit transmission unit 49 with respect to the intermediate transfer unit driving unit 119 in a surface orthogonal to the third direction 93 that is the insertion / removal direction of the unit assembly 10 with respect to the apparatus main body 110, that is, the facing surface 110B. A fourth positioning part 640 is further provided.

The fourth positioning portion 640 includes a protruding portion 641 provided coaxially with the intermediate transfer unit driving portion 119 and a concave portion 642 provided coaxially with the intermediate transfer unit transmission portion 49 and fitted with the protruding portion 641. . The protruding portion 641 has a cylindrical shape into which the intermediate transfer unit transmission portion 49 is fitted.

According to the image forming apparatus 100, the accuracy of the relative position between the units 200A to 200D and 4A to 4D in the apparatus main body 110 can be improved, so that the position between the processing unit transmission units 205A to 205D and 310A to 310D. Accuracy can be improved. Further, since the positional accuracy between the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D and the intermediate transfer unit 40 can be improved, the plurality of processing unit transmission units 205A to 205D, 310A to 310D and the intermediate transfer unit Position accuracy with respect to the transmission unit 49 can be improved.

Accordingly, at least one of the plurality of processing unit transmission units 205A to 205D, 310A to 310D and the intermediate transfer unit transmission unit 49 is replaced with one of the plurality of processing unit driving units 111 to 118 and the intermediate transfer unit driving unit 119. By aligning with the corresponding drive unit, other transmission units can be easily and accurately aligned with the corresponding drive unit. Therefore, when the unit assembly 10 is inserted into the apparatus main body 110, the processing unit transmission units 205A to 205D and 310A to 310D can be easily connected to the processing unit driving units 111 to 118, respectively, and the intermediate transfer unit transmission unit 49 can be easily connected to the intermediate transfer unit driving unit 119, and the plurality of process units 200A to 200D, the plurality of developing units 4A to 4D, and the intermediate transfer unit 40 can be smoothly driven.

Therefore, the positional accuracy between the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D and the positional accuracy between the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D and the intermediate transfer unit 40 are improved. In addition, the workability for supplying driving force to the plurality of process units 200A to 200D, the plurality of developing units 4A to 4D, and the intermediate transfer unit 40 can be improved.

In addition, since the intermediate transfer unit transmission unit 49 is accurately positioned with respect to the intermediate transfer unit drive unit 119 by the fourth positioning unit 640 without causing a positional shift, the driving force from the apparatus main body 110 to the intermediate transfer unit 40 is surely ensured. Can be supplied to. Accordingly, the plurality of processing unit transmission units 205A to 205D and 310A to 310D are also accurately aligned with respect to the plurality of processing unit driving units 111 to 118, and the plurality of process units 200A to 200D and the plurality of developing units 4A to 4D are aligned. It is possible to reliably supply the driving force.

Further, the intermediate transfer unit transmission unit 49 is accurately positioned with respect to the intermediate transfer unit driving unit 119, so that the intermediate transfer unit can be applied to the sheet conveying member before and after the secondary transfer position in the apparatus main body 110 in the sheet conveying direction. 40 can be accurately aligned, and conveyance troubles such as oblique feeding of paper passing through the secondary transfer position can be suppressed.

Further, the protrusion 641 and the recess 642 of the fourth positioning portion 640 are fitted to each other, so that the intermediate transfer unit transmission portion 49 can be easily and accurately positioned with respect to the intermediate transfer unit driving portion 119 with a simple structure. be able to.

Further, since the protrusion 641 is configured to have a cylindrical shape into which the intermediate transfer unit transmission unit 49 is fitted, the intermediate transfer unit driving unit 119 and the intermediate transfer unit transmission unit 49 can be positioned more easily. In addition, the intermediate transfer unit driving unit 119 and the intermediate transfer unit transmission unit 49 can be more accurately and reliably connected.

Note that the processing unit driving units 111 to 118 and the processing unit transmission units 205A to 205D and 310A to 310D, and the intermediate transfer unit driving unit 119 and the intermediate transfer unit transmission unit 49 are not limited to being connected coaxially. For example, two parallel rotation shafts that are not coaxial may be configured to transmit rotational force between spur gears.

As shown in FIG. 14, the image forming apparatus 100 according to the second embodiment can be configured such that the image forming unit 20 includes one type of processing units 500A to 500D. As described above, the types of processing units included in the image forming unit 20 are not particularly limited, and may be one type, two types, or three or more types. The positional accuracy between the unit and the intermediate transfer unit 40 can be improved, and the workability for supplying driving force to the plurality of processing units and the intermediate transfer unit 40 can be improved.

Even when another unit for forming a toner image is applied as the first processing unit in place of the process units 200A to 200D, the positional accuracy between the plurality of first processing units and the plurality of first processing units are used. The positional accuracy between the unit and the intermediate transfer unit 40 can be improved, and the workability for supplying driving force to the plurality of processing units and the intermediate transfer unit 40 can be improved.

The present invention can also be applied to the image forming apparatus 100 in which the unit assembly 10 having a single processing unit and the intermediate transfer unit 40 is configured to be detachable from the apparatus main body 110.

The unit assembly 10 is configured by holding the intermediate transfer unit 40 in the image forming unit 20 having a single processing unit. Since the single processing unit and the intermediate transfer unit 40 are integrated outside the apparatus main body 110 and are inserted into and removed from the apparatus main body 110 as the unit assembly 10, the assembly unit 10 and the intermediate transfer unit 40 are not assembled. It is not necessary to provide a space for preventing scratches, and the relative position accuracy between the units in the apparatus main body 110 can be improved as compared with the case where the units are individually inserted and removed. Further, it can be miniaturized by space saving. Furthermore, since the intermediate transfer unit 40 is held in the image forming unit 20, the positional accuracy between the single processing unit and the intermediate transfer unit 40 can be further improved. For this reason, the positional accuracy between the single processing unit transmission unit and the intermediate transfer unit transmission unit can be improved. Accordingly, when at least one of the single processing unit transmission unit and the intermediate transfer unit transmission unit is aligned with the corresponding driving unit of the single processing unit driving unit and the intermediate transfer unit driving unit, It is possible to easily and accurately align the transmission portion with the corresponding drive portion. Therefore, when the unit assembly 10 is inserted into the apparatus main body 110, the processing unit transmission unit can be easily connected to the processing unit driving unit, and the intermediate transfer unit transmission unit can be easily connected to the intermediate transfer unit driving unit, A single processing unit and an intermediate transfer unit can be driven smoothly.

Further, the present invention is not limited to being applied to a tandem type image forming apparatus.

The present invention is not limited to being applied to the image forming apparatus 100 including the apparatus main body 110 in which the mounting portion 110A and the paper discharge tray 62 are opened on different surfaces of the apparatus main body 110. The image forming apparatus 100 according to the third embodiment may be configured such that the mounting portion 110 A and the paper discharge tray 62 open on the same surface of the apparatus main body 110. For example, the mounting portion 110A and the paper discharge tray 62 may be opened on the front surface of the apparatus main body 110, or may be opened on either the left or right side. In the second embodiment, as shown in FIG. 15, the paper discharge tray 62 opens on a plurality of surfaces including both the same surface and different surfaces as the mounting portion 110A. For example, the paper discharge tray 62 opens on either the front side or the left and right side surfaces of the apparatus main body 110. 110 A of mounting parts and the paper discharge tray 62 are mutually opened on the same surface of the apparatus main body 110, and a user's operativity and work efficiency improve.

The description of the above-described embodiment is an example in all respects, and should be considered as not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1A to 1D Photosensitive drum 4A to 4D Development unit (second processing unit)
5A to 5D Primary transfer unit 10 Unit aggregate 20 Image forming unit 30A to 30D Image forming station 40 Intermediate transfer unit 80 Connecting member 91 First direction 92 Second direction 93 Third direction (insertion / removal direction)
DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Apparatus main body 110A Insertion part 200A-200D Process unit (1st processing unit)
201B shaft portion 202B

first contact portion

301A, 301B, 302B, 301C extending member

303B receiving portion

305B, 306B bearing portion 307B

second contact portion

308B,

309B buffer member

611, 612 first positioning portion 621-624 second Positioning portion 640 Fourth positioning portion 641 Protruding portion 642 Recessed portion

Claims

An image forming apparatus that performs electrophotographic image forming processing,
An apparatus main body, and a unit assembly configured to be detachable with respect to the apparatus main body,
The unit aggregate is
An image forming unit having a plurality of processing units and a connecting member that connects the plurality of processing units in a state of relative positioning to each other;
An intermediate transfer unit that carries a developer image formed by using the plurality of processing units and conveys the developer image to a transfer position to a sheet, and is held in a state where the image forming unit is positioned at a predetermined position. A unit,
The apparatus main body includes a plurality of processing unit driving units for supplying driving force for driving the plurality of processing units, respectively, and an intermediate transfer unit driving unit for supplying driving force for driving the intermediate transfer unit,
Each of the plurality of processing units has a processing unit transmission unit that receives a driving force from the processing unit driving unit,
The intermediate transfer unit has an intermediate transfer unit transmission unit that transmits a driving force from the intermediate transfer unit drive unit,
When the unit assembly is inserted into the apparatus main body, the processing unit transmission unit is connected to the processing unit driving unit, and the intermediate transfer unit transmission unit is connected to the intermediate transfer unit driving unit. , Image forming apparatus.
The image forming apparatus according to claim 1, further comprising a positioning unit that positions the intermediate transfer unit transmission unit with respect to the intermediate transfer unit driving unit in a plane orthogonal to an insertion / removal direction of the unit assembly with respect to the apparatus main body. .
3. The image forming apparatus according to claim 2, wherein the positioning portion includes a protruding portion and a concave portion that fits into the protruding portion.
The positioning unit includes a protrusion provided coaxially with the intermediate transfer unit driving part, and a recess provided coaxially with the intermediate transfer unit transmission part and fitted with the protrusion. The image forming apparatus described.
5. The image forming apparatus according to claim 4, wherein the protruding portion has a cylindrical shape into which the intermediate transfer unit transmission portion is fitted.
An image forming apparatus that performs electrophotographic image forming processing,
An apparatus main body, and a unit assembly configured to be detachable with respect to the apparatus main body,
The unit aggregate is
An image forming unit having a processing unit;
An intermediate transfer unit that carries a developer image formed by using the processing unit and conveys the developer image to a transfer position to a sheet,
The apparatus main body includes a processing unit driving unit that supplies a driving force for driving the processing unit, and an intermediate transfer unit driving unit that supplies a driving force for driving the intermediate transfer unit,
The processing unit has a processing unit transmission unit that transmits a driving force from the processing unit driving unit,
The intermediate transfer unit has an intermediate transfer unit transmission unit that transmits a driving force from the intermediate transfer unit drive unit,
When the unit assembly is inserted into the apparatus main body, the processing unit transmission unit is connected to the processing unit driving unit, and the intermediate transfer unit transmission unit is connected to the intermediate transfer unit driving unit. Image forming apparatus.