JP5496281B2 - Unit assembly and image forming apparatus - Google Patents

Description

  The present invention relates to a unit assembly mounted on a tandem type image forming apparatus that employs an intermediate transfer system that transfers a developer image onto a sheet via an intermediate transfer unit, and an image forming apparatus including the unit aggregate.

  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 transfer unit. 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, color misregistration occurs, and the image quality may be lowered.

  Therefore, an image forming apparatus having a configuration in which a plurality of process units are connected and integrated by mounting on a tray, and a configuration in which a plurality of process units are connected to each other by providing a connection portion in each of the plurality of process units is known. (For example, refer to Patent Document 1). In this conventional image forming apparatus, both positioning and connection fixing of a plurality of process units are performed by a single means such as a tray or a connection unit.

JP-A-9-304994

  However, in a conventional image forming apparatus in which a plurality of process units are connected and integrated by mounting on a tray, both the relative positioning and the connection and fixing between the plurality of process units are performed by the tray. If the tray is distorted or if the process unit is loosely attached to the tray, the positional accuracy is lowered even if the connection is fixed. Furthermore, since positioning and connection fixation are performed by a single means, it is difficult to finely adjust the position during connection. In addition, in the configuration in which a plurality of process units are connected to each other by providing a connection portion in each of the plurality of process units, backlash is likely to occur between the inner rail and the outer rail constituting the connection portion, and only a decrease in position accuracy is caused. In addition, there is a risk that the stability of the coupling and fixing is lowered. Furthermore, in the above-described conventional image forming apparatus, no consideration is given to the improvement of the positional accuracy between the process unit and the intermediate transfer unit.

  An object of the present invention is to provide a unit assembly capable of improving the positional accuracy between a plurality of first processing units and also improving the positional accuracy between an image forming unit having a plurality of first processing units and an intermediate transfer unit, And providing an image forming apparatus including the same.

  The unit assembly of the present invention is configured to be detachable with respect to the apparatus main body of an image forming apparatus that performs electrophotographic image forming processing. The unit aggregate includes an image forming unit and an intermediate transfer unit. The image forming unit includes a plurality of first processing units, a positioning unit, and a connecting member. The plurality of first processing units each include a first image forming member among a plurality of image forming members that form a developer image. The positioning unit positions the plurality of first processing units relative to each other. The connecting member connects the plurality of first processing units in a state where the relative positioning is performed. The intermediate transfer unit carries a developer image formed by a plurality of image forming members and conveys it to a transfer position to a sheet. The intermediate transfer unit is held by the image forming unit.

  In this configuration, the plurality of first processing units are connected and fixed and integrated to form an image forming unit, and the image forming unit holds the intermediate transfer unit to form a unit aggregate. Since the plurality of first processing units and the intermediate transfer unit are integrated outside the apparatus main body and are inserted into and removed from the apparatus main body as a unit aggregate, there is a damage during assembly between the first processing unit and the intermediate transfer unit. It is not necessary to provide a space for prevention, 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. Furthermore, the size can be reduced by space saving.

  Further, since the plurality of first processing units are positioned relative to each other by the positioning unit provided separately from the connecting member, the positioning unit can be miniaturized, and the positioning unit can be distorted and bent. Can be suppressed. For this reason, compared with the case where both positioning and connection fixation are performed by a single means, the positional accuracy between the plurality of first processing units can be improved. In addition, since the plurality of positioned first processing units are further connected by the connecting member, the accurately positioned state can be stabilized. Furthermore, since positioning and connection are performed by different means, fine adjustment of the position can be easily performed at the time of connection. Thus, by providing the positioning portion and the connecting member separately, both the positional accuracy and the stability of the connecting and fixing can be improved as compared with the case where the positioning and the connecting and fixing are provided as a single means. Further, as described above, since the unit aggregate is inserted into and removed from the apparatus main body in a state where the image forming unit holds the intermediate transfer unit outside the apparatus main body to form a unit aggregate, the image forming unit and the intermediate transfer unit The positional accuracy between the two can also be improved. For this reason, it is possible to suppress the shift of the image transferred from the image forming unit to the intermediate transfer unit, and to improve the image quality.

  In the above-described configuration, the image forming unit further includes a plurality of second processing units each including a second image forming member among the plurality of image forming members, and the plurality of first processing units includes a plurality of second processing units. Each of the plurality of second processing units is held by each of the units, and the positioning unit may be configured to relatively position the plurality of second processing units relative to each other.

  In this configuration, since the positioning unit is provided in each of the second processing units, each positioning unit only needs to be able to regulate the interval between two adjacent second processing units. For this reason, compared with the case where positioning of all the 2nd processing units is performed by one member, since a positioning part can be reduced in size, it is hard to produce distortion and a deflection of a positioning part, and between two or more 2nd processing units. Position accuracy can be improved. Therefore, the positional accuracy between the plurality of first processing units can be improved. Further, the positional accuracy between the first processing unit and the second processing unit can be improved.

  The image forming unit further includes a plurality of third processing units each including a third image forming member among the plurality of image forming members, and the plurality of third processing units are respectively provided to the plurality of second processing units. It can be configured to be retained.

  In this configuration, since the third processing unit is held in each of the plurality of second processing units positioned with high accuracy, the positional accuracy between the plurality of third processing units can be improved. In addition, the positional accuracy among the first processing unit, the second processing unit, and the third processing unit can be improved.

  Further, the first image forming member can be a photosensitive drum. In this configuration, the first processing unit is a process unit including a photosensitive drum. By accurately positioning the plurality of process units relative to each other, the positional accuracy between the plurality of photosensitive drums can be improved.

  Further, the second image forming member can be a developer carrier that supplies the developer to the photosensitive drum. In this configuration, the second processing unit is a developing unit including a developer carrier. The positional accuracy between the first processing unit and the developing unit can be improved. For example, the positional accuracy between the photosensitive drum and the developer carrier can be improved.

  Further, the third image forming member can be an exposure member that forms an electrostatic latent image by irradiating light onto a photosensitive drum charged to a predetermined potential. In this configuration, the third processing unit is an exposure unit including an exposure member. The positional accuracy among the first processing unit, the second processing unit, and the exposure unit can be improved. For example, the positional accuracy among the photosensitive drum, the developer carrier, and the exposure member can be improved.

  The image forming apparatus of the present invention includes the unit assembly having any one of the above-described configurations.

  In this configuration, since the plurality of first processing units and the intermediate transfer unit are inserted into and removed from the apparatus main body as a unit aggregate, positional deviation in the apparatus main body is suppressed compared to the case where the units are individually inserted and removed. Is done.

  Moreover, since the positioning part can be reduced in size and distortion and bending of the positioning part can be suppressed, the positioning between the plurality of first processing units can be performed as compared with the case where both positioning and connection fixing are performed by a single means. The position accuracy of the is improved. Furthermore, it is possible to stabilize the accurately positioned state. Further, fine adjustment of the position can be easily performed at the time of connection. Thus, compared with the case where positioning and fixing are provided as a single means, both the positional accuracy and the stability of connection and fixing can be improved. Also, the positional accuracy between the image forming unit and the intermediate transfer unit can be improved. For this reason, the shift of the image transferred from each of the plurality of first processing units to the intermediate transfer unit is suppressed, and the image quality is improved.

  According to the present invention, the positional accuracy between the plurality of first processing units can be improved, and the positional accuracy between the image forming unit having the plurality of first processing units and the intermediate transfer unit can also be improved.

1 is a front sectional view showing a schematic configuration of an image forming apparatus including a unit assembly according to an 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 1st processing unit and a development unit. FIG. 6 is a front view showing a state in which a plurality of first processing 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 perspective view from the diagonally left side of the developing unit showing a receiving part of a positioning part according to a first modification. It is a perspective view from the diagonally left side of the developing unit showing a receiving part of a positioning part according to a second modification. (A)-(C) are the front views of the image development unit which has the positioning part which concerns on a 3rd modification. (A)-(C) are the front views of the image development unit which has the positioning part which concerns on a 4th modification. (A)-(C) are the front views of the image development unit which has the positioning part which concerns on a 5th modification. It is a front view of a unit aggregate concerning other examples of composition. It is a front view of a unit aggregate concerning still another example of composition.

  An image forming apparatus 100 including a unit assembly 10 according to an 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) 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. Form in 30A-30D. The image forming stations 30 </ b> A to 30 </ b> D are arranged in a line along the moving 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 receiving 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 image data of hues of black, cyan, magenta, and yellow, respectively. To do. Electrostatic latent images based on image data of black, cyan, magenta, and yellow hues are formed on the peripheral surfaces of the photosensitive drums 1A to 1D, respectively.

  The developing unit 4A supplies black toner (developer) that 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.

  To the primary transfer roller 5A, a primary transfer bias having a toner charging polarity (for example, minus) and a reverse polarity (for example, plus) is applied by constant voltage control. 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 1 </ b> A to 1 </ b> D are primarily transferred to the outer peripheral surface of the intermediate transfer belt 41 while being sequentially superimposed on 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 a part corresponding to the hue of the input image data among the four photosensitive drums 1A to 1D. 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 sheet conveyance path 61 is formed so as to reach the sheet discharge tray 62 from each of the sheet feed cassette 151 and the manual feed tray 152 via the secondary transfer position and the fixing device 70.

  The secondary transfer roller 51 is in pressure contact with the drive 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 or more types of image forming members, which are members for forming toner images, are unitized as processing units. 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 unit assembly 10 is configured to be detachable from 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, the unit assembly 10 according to the first embodiment includes an intermediate transfer unit 40, a connecting member 80, and a plurality of first processing units 200A, 200B, 200C, 200D and a plurality of developing units 4A, 4B, 4C, 4D. The developing units 4A to 4D each include a developing roller and correspond to a second processing unit. As an example, the first processing units 200A to 200D are process units including the photosensitive drums 1A to 1D, respectively. 3, FIG. 7 to FIG. 9 and FIG. 12 to FIG. 15 schematically show the first processing 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.

  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 4 </ b> B 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.

  As a result, when the developing unit 4B is placed on the work table and the first processing unit 200B is held by the developing unit 4B, the stability of the developing unit 4B is increased, and workability is improved.

  Here, the 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 direction 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 that faces a later-described image forming unit 20 (see FIG. 9). 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 positioning part. The 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> B and 302 </ b> B are provided at the first end of the developing unit 4 </ b> B in the first direction 91 and at both ends of the developing unit 4 </ b> B in the third direction 93. The receiving portions 303 </ b> B and 304 </ b> B are provided at the second end of the developing unit 4 </ b> B in the first direction 91 and at both ends of the developing unit 4 </ b> 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 extension 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. Thereby, 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 first processing 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 first processing 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 a predetermined second of the developing unit 4B. It is comprised so that it may contact | abut to the contact part 307B. The second contact portion 307B has a shape along the outer shape of the first contact portion 202B.

  With the space between the first contact portion 202B of the first processing unit 200B and the second contact portion 307B of the developing unit 4B, the shaft portion 201B of the first processing unit 200B is replaced with the bearing portion 305B of the developing unit 4B. , 306B, and from this state, the first processing unit 200B is rotated around the shaft portion 201B. As a result, the first processing 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. Thus, it is possible to position and to prevent the first processing unit 200B and the developing unit 4B from being damaged during the assembly operation.

  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 first processing 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 damage of the first processing unit 200B and the developing unit 4B can be further suppressed.

  As described above, the first processing units 200A to 200D are held by the developing units 4A to 4D, respectively, and the developing units 4A to 4D are positioned relative to each other, as shown in FIG. The plurality of first processing units 200A to 200D and the plurality of developing units 4A to 4D are accurately positioned. Note that either the first processing unit 200A to 200D can be held by the developing units 4A to 4D and the relative positioning of the developing units 4A to 4D can be performed first.

  As shown in FIG. 8, the plurality of first processing units 200A to 200D are respectively held by the plurality of developing units 4A to 4D, and the plurality of developing units 4A to 4D are positioned relative to each other. In this state, the plurality of developing units 4 </ b> A to 4 </ b> D are connected by the connecting member 80. In FIG. 8, the connecting member 80 is hatched for convenience of explanation.

  The connecting member 80 has a plate shape and is disposed on the front side and the back side of the plurality of first processing units 200A to 200D and the plurality of developing units 4A to 4D, respectively.

  The connecting member 80 is provided with a through hole at a position corresponding to the screw hole provided in each of the plurality of developing units 4A to 4D. The through hole of the connecting member 80 is preferably a long hole. The connecting member 80 is screwed into the screw holes of the plurality of developing units 4A to 4D through the through holes, thereby fixing the relative positions of the developing units 4A to 4D. A washer 81 is preferably used for screwing.

  When the through holes are long holes in the first direction 91 or the second direction 92, the relative positions of the plurality of developing units 4A to 4D can be finely adjusted.

  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 first processing 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.

  As an example, the intermediate transfer unit 40 is fixed to the image forming unit 20 by being screwed using a washer.

  According to the unit assembly 10, the plurality of first processing units 200A to 200D are held by the plurality of developing units 4A to 4D, and the plurality of developing units 4A to 4D are connected and fixed to be integrated to form the image forming unit 20. Further, the unit assembly 10 is configured by the image forming unit 20 holding the intermediate transfer unit 40.

  Since the plurality of first processing units 200 </ b> A to 200 </ b> D, the plurality of developing units 4 </ b> A to 4 </ b> D, 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. Compared to the case where the units 200A to 200D, 4A to 4D, and 40 are individually inserted and removed, there is no need to provide a space between the units 200A to 200D, 4A to 4D, and 40 for preventing scratches during assembly. The accuracy of the relative position between the units 200A to 200D, 4A to 4D, 40 in the apparatus main body 110 can be improved. Furthermore, the size can be reduced by space saving.

  Further, since the positioning portion is provided in each of the developing units 4A to 4D separately from the connecting member 80, each of the positioning portions only needs to be able to define the interval between the two adjacent developing units 4A to 4D. For this reason, as compared with the case where positioning of all the developing units 4A to 4D is performed by one member, the positioning unit can be downsized, and thus the positioning unit is less likely to be distorted or bent. Thereby, the positional accuracy between the plurality of developing units 4A to 4D can be improved as compared with the case where both positioning and connecting and fixing are performed by a single means. Therefore, the positional accuracy between the plurality of first processing units 200A to 200D can be improved. In addition, since the plurality of positioned developing units 4A to 4D are further connected by the connecting member 80, the accurately positioned state can be stabilized. Furthermore, since positioning and connection are performed by different means, fine adjustment of the position can be easily performed at the time of connection. Thus, by providing the positioning portion and the connecting member 80 separately, both the positional accuracy and the stability of the connecting and fixing can be improved as compared with the case where the positioning and the connecting and fixing are provided as a single means. .

  Further, 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.

  Further, by bringing the extension portion 301C and the receiving portion 303B into contact with each other, the relative positioning of the developing units 4B and 4C adjacent to each other can be accurately performed. The same applies to positioning between the developing units 4A and 4B and between the developing units 4C and 4D. Furthermore, the position accuracy can be improved with a simple structure.

  Further, since the receiving portion 303B restricts the movement of the extending portion 301C in the first direction 91, the interval between the plurality of developing units 4A to 4D can be accurately defined. For this reason, the positional accuracy in the 1st direction 91 between several developing unit 4A-4D can be improved.

  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 inside the apparatus main body 110. The workability of the assembly work of the image forming apparatus 100 can be improved.

  Next, a modified example of the positioning unit will be described. For convenience of explanation, the same reference numerals are used for members configured in the same manner as described above.

  As shown in FIG. 10, the receiving portion 303B of the positioning portion according to the first modification further includes a third protrusion 303B3 that contacts the extending portion 301C of the developing unit 4C from at least one side in the second direction 92. Configured as follows. As an example, the third protrusion 303B3 abuts on the extended portion 301C from below.

  By causing the extending portion 301C of the developing unit 4C to contact the third protruding portion 303B3 of the developing unit 4B, the third protruding portion 303B3 restricts the movement of the extending portion 301C in at least one direction in the second direction 92. For this reason, the position in the second direction 92 of the developing unit 4C with respect to the developing unit 4B is defined. Thereby, the positional accuracy in the second direction 92 between the plurality of developing units 4A to 4D can be improved.

  It is also possible to further include a fourth protrusion that abuts the extended portion 301C from above, and the extended portion 301C is sandwiched from the vertical direction and the horizontal direction.

  As shown in FIG. 11, the receiving portion 303B of the positioning portion according to the second modified example is configured by one protrusion 303B2 that abuts the extension portion 301C of the developing unit 4C from one side in the third direction 93. The

  By causing the extending portion 301C of the developing unit 4C to contact the protruding portion 303B2 of the developing unit 4B, the protruding portion 303B2 restricts the movement of the extending portion 301C in one direction in the third direction 93. For this reason, the position of the developing unit 4C in the third direction 93 with respect to the developing unit 4B is defined. This also improves the positional accuracy in the third direction 93 between the plurality of developing units 4A to 4D.

  In the third to fifth modifications shown in FIGS. 12 (A) to 12 (C), FIGS. 13 (A) to 13 (C), and FIGS. 14 (A) to 14 (C), the extending portion is used. 301B and 302B extend from the developing unit 4B toward the developing unit 4C by a predetermined length. The receiving portions 303B and 304B are configured to receive the extending portions 301A and 302A of the developing unit 4A (however, the extending portion 302A is not shown).

  The developing unit 4B is arranged at a location other than both ends in the first direction 91, and the developing unit 4C arranged at a location other than the other ends of the developing unit 4B is configured similarly to the developing unit 4B. . The developing unit 4D 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 4A 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.

  Further, in the following description, for convenience of explanation, description will be made using the reference numerals of the extension portions 301A and 302A and the receiving portions 303B and 304B, but the same applies to the extension portions and receiving portions of the other developing units 4A to 4D. is there.

  The receiving portions 303B and 304B are recessed portions into which the extending portions 301A and 302A of the developing unit 4A are respectively fitted. The unit assembly 10 includes a plurality of sets of extending portions 301A and 302A and receiving portions 303B and 304B that are in contact with each other.

  As shown in FIGS. 12 (A) to 12 (C), in the third modified example, the extension portions 301A and 302A and the receiving portions 303B and 304B between the sets are arranged in the second direction 92 or the third direction 93. At least one of the developing units 4A to 4D in one direction is configured to have different installation positions.

  As an example, the extension parts 301A and 302A and the receiving parts 303B and 304B are configured to have different heights between the groups.

  The extension portions 301A and 302A and the receiving portions 303B and 304B that are fitted to each other have the same installation positions in the developing units 4A to 4D in both the second direction 92 and the third direction 93. .

  In the configuration of the third modified example, as shown in FIG. 12B, the receiving portions 303B and 304B of the developing unit 4B and the extending portions 301A and 302A of the developing unit 4A are fitted, and similarly, adjacent to each other. By fitting the receiving part of the developing unit and the extending part, the positional accuracy between the plurality of developing units 4A to 4D can be improved. In addition, since the installation positions of the developing units 4A to 4D in the extending portion and the receiving portion are different from each other, the arrangement order of the plurality of developing units 4A to 4D is defined. For this reason, as shown in FIG. 12C, when the arrangement order is not correct, at least one set of the extending portion and the receiving portion cannot be fitted. Accordingly, it is possible to prevent an error in the arrangement order of the plurality of developing units 4A to 4D.

  As shown in FIGS. 13 and 14, the fourth modification and the fifth modification are configured such that the shapes of the extension parts 301 </ b> A and 302 </ b> A and the receiving parts 303 </ b> B and 304 </ b> B are different from each other.

  Specifically, as shown in FIG. 13, in the fourth modification, the extension amounts of the extension portions 301A and 302A and the depths of the receiving portions 303B and 304B are different from each other between the groups. Is done. As shown in FIG. 14, in the fifth modification, the thicknesses of the extending portions 301A and 302A and the receiving portions 303B and 304B, that is, the dimensions in the second direction 92 and the third direction 93 are different from each other. Configured.

  The shapes of the extending portions 301A and 302A and the receiving portions 303B and 304B that fit into each other are the same.

  In the configuration of the fourth modification and the fifth modification, as shown in FIGS. 13B and 14B, the receiving portions 303B and 304B of the developing unit 4B and the extending portions 301A and 302A of the developing unit 4A By fitting the receiving portions and the extending portions of the developing units adjacent to each other, the positional accuracy between the plurality of developing units 4A to 4D can be improved.

  In addition, since the shapes of the extending portion and the receiving portion are different from each other, the arrangement order of the plurality of developing units 4A to 4D is defined. For this reason, as shown in FIG. 13C and FIG. 14C, when the arrangement order is not correct, at least one set of the extending portion and the receiving portion cannot be fitted. Accordingly, it is possible to prevent an error in the arrangement order of the plurality of developing units 4A to 4D.

  In addition, it can also comprise so that the magnitude | size of an extending part and a receiving part may differ between each group.

  As shown in FIG. 15, in the unit assembly 10 according to another configuration example, the image forming unit 20 includes third processing units 400A to 400D in addition to the first processing units 200A to 200D and the developing units 4A to 4D. Further prepare. As an example, in this configuration example, instead of the optical scanning device 3, each of the image forming stations 30A to 30D includes an optical scanning unit, and the third processing units 400A to 400D correspond to the optical scanning unit. The third processing units 400A to 400D each include an exposure member that forms an electrostatic latent image by irradiating light to the photosensitive drums 1A to 1D charged to a predetermined potential.

  The plurality of third processing units 400A to 400D are held by the plurality of developing units 4A to 4D, respectively.

  In this configuration example, since the third processing units 400A to 400D are held in the plurality of developing units 4A to 4D that are positioned with high accuracy, the positional accuracy between the plurality of third processing units 400A to 400D can be improved. . In addition, the positional accuracy among the first processing units 200A to 200D, the developing units 4A to 4D, and the third processing units 400A to 400D can be improved.

  As shown in FIG. 16, the image forming unit 20 may be configured to include one type of processing units 500 </ b> A to 500 </ b> D, a positioning unit, and a connecting member 80. As described above, the types of processing units included in the image forming unit 20 are not particularly limited, and can be one type, two types, or three or more types, and can improve the positional accuracy between the plurality of processing units. The positional accuracy between the image forming unit 20 having a plurality of processing units and the intermediate transfer unit 40 can also be improved.

  In addition, the positioning unit can be configured as a separate body from the developing units 4A to 4D.

  In addition, when another unit for forming a toner image is used as the developing unit instead of the developing units 4A to 4D, the positional accuracy between the plurality of first processing units 200A to 200D can be improved. The effect that the positional accuracy between the image forming unit 20 having the plurality of first processing units 200 </ b> A to 200 </ b> D and the intermediate transfer unit 40 can also be improved can be achieved.

  The above description of the embodiment is to be considered in all respects as illustrative and 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 Developing unit (second processing unit)
DESCRIPTION OF SYMBOLS 10 Unit aggregate 20 Image forming unit 30A-30D Image forming station 40 Intermediate transfer unit 80 Connecting member 91 1st direction 92 2nd direction 93 3rd direction (insertion / removal direction)
DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Main body 200A-200D 1st processing unit 201B Shaft part 202B 1st contact part 301A, 301B, 302B, 301C Extension member 303B Reception part 305B, 306B Bearing part 307B 2nd contact part 308B, 309B Buffer member 400A to 400D Third processing unit

Claims (5)

A unit assembly configured to be detachable with respect to an apparatus main body of an image forming apparatus that performs electrophotographic image forming processing,
A plurality of first processing units each including a first image forming member among a plurality of image forming members forming a developer image;
A plurality of second processing units each including a second image forming member of the plurality of image forming members and holding the plurality of first processing units;
Positioning unit, and an image forming unit having a connecting member, for connecting together said plurality of second processing units in a state of being the relative positioning of each other for the mutual relative positioning of the plurality of second processing units When,
An intermediate transfer unit that holds a developer image formed by the plurality of image forming members and conveys the developer image to a transfer position to a sheet, and is held by the image forming unit,
The second processing unit is a unit assembly that is a developing unit . The image forming unit further includes a plurality of third processing units each including a third image forming member of the plurality of image forming members,
Wherein the plurality of third processing unit, wherein each is held in a plurality of the second processing unit, unit assembly according to claim 1. The unit assembly according to claim 2 , wherein the third image forming member is an exposure member that forms an electrostatic latent image by irradiating light onto a photosensitive drum charged to a predetermined potential.   The unit assembly according to claim 1, wherein the first image forming member is a photosensitive drum. An image forming apparatus comprises a unit assembly according to any one of claims 1 4.

Images