JP2000056658A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the maintenability of an image carrier in an image forming device which forms a toner image on an image carrier, the toner image is transferred to a transfer material, then transfer residual toner stuck to the surface of the image carrier is removed by a cleaning device. SOLUTION: An image-carrier unit 41 is configured by fitting the image carrier 5 to a unit holder 40. The image-carrier unit 41 is detachably set to a drawer body 45 so mounted in an image forming device main body 1 as to be freely drawn. When the drawer body 45 is set into the image forming device main body 1, the image carrier 5 is aligned with the image forming device main body 1 via a driving shaft 72 at the rear of the image forming device main body 1 and a follower shaft 81 at the front.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming a toner image on a surface of an image carrier and transferring the toner image to a transfer material.

[0002]

2. Description of the Related Art An image forming apparatus of the above-mentioned type configured as an electronic copying machine, a printer, a facsimile or a multifunction machine having at least two of these functions has been well known. In order to improve the maintainability of such an image forming apparatus, an image carrier is configured by holding the image carrier in a unit holder, and the image carrier unit is drawn out so as to be removably mounted to the image forming apparatus main body. It is advantageous to hold it detachably on the body. With this configuration of the image forming apparatus, in order to take out the image carrier from the image forming apparatus main body, first, the drawer housed in the image forming apparatus main body is pulled out to the operator side, that is, to the front side, and then the What is necessary is just to take out the held image carrier unit from the drawer. By performing the reverse operation, the image carrier unit can be very easily set in the main body of the image forming apparatus.

The image carrier has a surface on which a toner image is formed. To improve the image quality of the toner image, the image carrier is positioned with high precision with respect to the image forming apparatus main body. Need to set.

However, as described above, if an image carrier unit is constructed by holding the image carrier in a unit holder and is housed in a drawer so as to be detachable, the image carrier is provided around the image carrier. , The unit holder and the drawer are present, so that when the drawer is pushed into the back of the image forming apparatus main body and is loaded into a predetermined position, the image carrier is correctly positioned with respect to the image forming apparatus main body. In such a configuration, the structure becomes extremely complicated, and the operation at this time becomes complicated. As described above, the adoption of the configuration of the image carrier unit and the drawer supporting the same improves the maintainability of the image forming apparatus.On the other hand, when the drawer is mounted on the image forming apparatus main body, It is inevitable that a simple operation makes it difficult to correctly position the image carrier with respect to the image forming apparatus main body.

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on the above-described novel recognition, and has as its object to provide an image carrier unit and a drawer for detachably holding the image carrier unit. In addition to adopting a simple configuration,
In addition, an object of the present invention is to provide an image forming apparatus capable of positioning the image carrier in the image forming apparatus main body by a simple operation.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image carrier unit having an image carrier having a toner image formed on a surface thereof in a unit holder, and the image carrier unit. , Which is detachably held in the main body of the image forming apparatus and is detachably mounted on the main body of the image forming apparatus; a drive shaft for driving the image carrier; and a rotatable support for the drive shaft; When the drive shaft holder fixed to the rear side plate on the back side of the main body and the drawer is loaded at a predetermined position of the image forming apparatus main body, the rear end of the back side of the image carrier and the drive shaft are mutually moved. An engaging means for engaging the relative non-rotation and positioning the rear end of the image carrier with respect to the drive shaft; and, when the drawer is loaded at a predetermined position of the image forming apparatus main body, the drawer is imaged. Positioning means for positioning with respect to the forming apparatus main body; A driven shaft that is fitted to the front end of the image carrier on the front side in a relatively non-rotatable manner, and the driven shaft is rotatably supported, and the drawer is mounted at a predetermined position of the image forming apparatus main body. Fitting into the holes formed in the unit holder of the drawer and the image carrier unit,
An image forming apparatus comprising: a driven shaft holder that positions the front side of the unit holder with respect to the drawer and positions the front end of the image carrier with respect to the drawer via the driven shaft. We propose (Claim 1).

At this time, the drive shaft is rotatably supported by a drive shaft holder via a rolling bearing, and an outer race of the rolling bearing is pressed into the drive shaft holder and fixed.
It is advantageous if the inner race of the rolling bearing is pressed into the drive shaft and fixed.

In the image forming apparatus according to the second aspect of the present invention, a hole formed in a rear side plate on the back side of the unit holder is fitted into an outer race of the rolling bearing, and the rear side plate of the unit holder is used as an image. It is advantageous if it is configured to be positioned with respect to the forming apparatus body (claim 3).

Further, in the image forming apparatus according to any one of claims 1 to 3, the driven shaft is fixed to a driven shaft holder, the driven shaft is fitted to a front end of the image carrier, and the driven shaft is It is advantageous to provide a fixing member that is fixed to the front side plate of the image forming apparatus main body in a state where the holder is fitted into the drawer and the hole of the unit holder, respectively.

Further, in the image forming apparatus according to any one of claims 1 to 4, an intermediate transfer member for transferring a toner image formed on an image carrier, and a frame for supporting the intermediate transfer member. A unit, wherein the fixed member engages with the frame of the intermediate transfer body in a state where the driven shaft holder is fitted in each of the holes of the drawer body and the unit holder, and forms the intermediate transfer body with the image forming apparatus. Advantageously, it is arranged to be positioned with respect to the body (claim 5).

Further, in the image forming apparatus according to any one of claims 1 to 5, the engaging means is fixed to the drive shaft and is reduced in diameter toward the front side of the image forming apparatus main body. A joint having a tapered surface, an engagement surface formed at a rear end portion of the image carrier, with which the tapered surface of the joint is engaged, and a driven shaft rotatable with the driven shaft; It is advantageous to provide a spring that presses the body to the back side and engages the engagement surface and the tapered surface of the joint so that they cannot rotate relative to each other (claim 6).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing the internal structure of a color copying machine as an example of an image forming apparatus as viewed from the front side. When a color copy is made by the color copying machine, an original (not shown) is placed on a contact glass 2 fixed on an upper portion of the image forming apparatus main body 1 and pressed by a pressure plate 3 to be shown. No start switch pressed. Thereby, the reading optical system 4 operates,
The document image is read.

On the other hand, an image carrier 5 is disposed inside the image forming apparatus main body 1. In the example shown in the figure, an image carrier composed of a drum-shaped photosensitive member is used. The image carrier 5 is driven to rotate in the counterclockwise direction in FIG. 1. At this time, the surface of the image carrier is made uniform to a predetermined polarity by the discharging action of a charging charger 6 comprising a corona discharger, which is an example of a charging device. Is charged.

A laser writing unit 7, which is an example of an exposure device, is disposed above the image carrier 5, and from the writing unit 7, a laser light modulated according to image information read by the reading optical system 4. Light L is emitted,
The laser beam L is applied to the charged surface of the image carrier as described above, whereby a first electrostatic latent image is formed on the surface of the image carrier.

A rotary developing device 8 which is an example of a developing device is disposed adjacent to the image carrier 5.
Has a black developing unit 8BK, a cyan developing unit 8C, a magenta developing unit 8M, and a yellow developing unit 8Y. Each developing device has developing rollers 9BK, 9C, 9M, 9Y,
When the above-described first electrostatic latent image passes through the developing device 8, the first developing device, in this example, the black developing device 8BK occupies the developing position facing the image carrier, and is carried by the developing roller 9BK. The first electrostatic latent image is visualized as a black toner image by a black developer (not shown). Thus, a toner image is formed on the surface of the image carrier 5. As the developer, a two-component powdery developer having a toner and a carrier is used, but a powdery one-component developer having no carrier can also be used.

On the other hand, on the surface of the image carrier, an intermediate transfer member 11 composed of a flexible endless belt wound around a plurality of rollers 10 including a driving roller is opposed to each other. While being rotated, a part of the surface comes into contact with the surface of the image carrier, and at the contact portion, the surface moves at the same linear velocity as the linear velocity of the image carrier surface in the same direction as the moving direction of the image carrier surface. . The black toner image formed on the surface of the image carrier is transferred to the surface of the intermediate transfer member 11 by the discharging operation of the primary transfer device 12 including, for example, a corona discharger. As described above, in the present example, the intermediate transfer member 11
Constitute a transfer material on which the toner image on the surface of the image carrier is transferred.

After transfer of the toner image to the intermediate transfer member 11, the transfer residual toner adhered to the surface of the image carrier is removed by a cleaning device 14, and then the surface of the image carrier is irradiated with light by a charge removing lamp 15. The absolute value of the surface potential is reduced to a reference value.

Then, exactly as described above,
A second electrostatic latent image is formed on the surface of the image carrier. At this time, by the rotation of the developing device 8, the second developing device, in this example, the cyan developing device 8C occupies the developing position facing the surface of the image carrier, and the second developing device 9C is moved by the cyan developer carried on the developing roller 9C. The two electrostatic latent images are visualized as cyan toner images. This toner image is also transferred onto the surface of the intermediate transfer body 11 in a superimposed state from above the previously transferred black toner image. The surface of the image bearing member after the transfer of the toner image is cleaned by the cleaning device
As a result, there is no difference from the operation at the time of the previous operation.

Further, in exactly the same manner as described above, the third and fourth electrostatic latent images sequentially formed on the surface of the image carrier are transferred to the respective developing devices of the magenta developing device 8M and the yellow developing device 8Y of the developing device 8. The magenta developer and the yellow developer carried on the rollers 9M and 9Y sequentially visualize the magenta toner image and the yellow toner image as a magenta toner image and a yellow toner image.
The toner images are sequentially transferred onto the surface of the intermediate transfer member in a state of being superimposed on the previously transferred toner image. In this manner, four color toner images are formed on the surface of the intermediate transfer member in a superimposed state.

On the other hand, a secondary transfer device 18 composed of, for example, a corona discharger is disposed to face the intermediate transfer member 11, and a sheet feeder 16 disposed below the secondary transfer device 18 is an example of a final transfer material. A transfer sheet P is fed in the direction of arrow A. The transfer paper P is sent between the secondary transfer device 18 and the intermediate transfer member 11 at a timing matching the toner image on the intermediate transfer member 11 by the rotation of the registration roller pair 17. At this time, due to the discharging action of the secondary transfer device 18, the superposed toner image on the surface of the intermediate transfer member is collectively transferred to the surface of the transfer paper moving while contacting the surface of the intermediate transfer member.

The transfer paper P on which the toner image has been transferred is carried and transported on a transport belt 19, and when passing through a fixing device 20, the toner image on the transfer paper is applied to the surface of the transfer paper by the action of heat and pressure. Be established. Next, the transfer paper is discharged onto a discharge tray 21 outside the machine as the final copy paper.

After transfer of the toner image onto the transfer paper P, the transfer residual toner adhering to the surface of the intermediate transfer member is removed from the surface of the intermediate transfer member by the cleaning member 23 of the cleaning device 22. The cleaning member 23 is separated from the surface of the intermediate transfer member 11 when the toner image on the intermediate transfer member 11 before being transferred passes through the cleaning member 23.

FIG. 2 is a cross-sectional view showing the details of the rotary developing device 8. This developing device 8 has a rear side plate 24 and a front side plate 24A (see FIGS. 6, 8 and 9). Has,
The side plates 24, 24A are integrally connected by a support 25, and the developing units 8BK, 8C, 8M, 8Y described above are detachably supported by the side plates 24, 24A and the support 25, respectively. Each of the developing devices includes a developing case 26BK, 26C, which accommodates a powdery developer (not shown).
26M and 26Y, respectively, and inside the developing rollers 9BK, 9C, 9M and 9Y, the first conveying screws 27BK, 27C, 27M and 27Y, and the second conveying screws 28BK, 28C, 28M and 28Y. Are rotatably arranged, and doctor blades 29BK, 29C, 29M, 29Y are fixedly arranged in the respective developing cases.

The developer in the developing case 26BK of the developing unit 8BK occupying the developing position facing the image carrier 5 is transported from the rotating second transport screw 28BK to the first transport screw 27BK, and the developer is transferred to the first transport screw 27BK. Is carried by the developing roller 9BK rotating clockwise and conveyed. At this time, the amount of the developer conveyed by the doctor blade 29BK is regulated, and the regulated developer is supplied to the developing roller 9BK.
And the toner in the developer is electrostatically transferred to an electrostatic latent image, and the electrostatic latent image is visualized as a toner image of a predetermined color. You.

Each developing device has a toner cartridge 30.
BK, 30C, 30M, and 30Y are mounted, and toner of each color is supplied to each developing case from each toner cartridge.

In the developing device 8 described above, the support 25 is supported by the central shaft 31 so as not to rotate relative to the central shaft 31.
Are rotatably supported with respect to the image forming apparatus main body 1 as described later, and the entire developing device 8 is rotationally driven by a driving device (not shown) so that each developing device is attached to the image carrier 5. It can occupy opposed development positions.

On the other hand, as shown in FIG. 3, the cleaning device 14 has a cleaning case 32 and a cleaning member for removing the transfer residual toner on the surface of the image carrier, and the cleaning device 14 shown in FIG. A cleaning blade 33 whose part is fixed to the cleaning case 32 and whose leading edge portion is pressed against the surface of the image carrier; and a cleaning brush 34 which is disposed inside the cleaning case 32 and is rotatably supported and rotatably supported by the case. Cleaning member is used. The cleaning case 32 is positioned with its opening 35 facing the surface of the image carrier 5. Reference numeral 36 denotes a seal member having one end fixed to the cleaning case 32 and a front end portion lightly in contact with the surface of the image carrier 5.

The transfer residual toner removed from the surface of the image carrier by the cleaning blade 33 and the cleaning brush 34 is stored in the cleaning case 32. At this time, the opening 35 is sealed by the seal member 36 and the cleaning blade 33, and the toner is prevented from scattering to the outside of the cleaning case through the opening 35.

As shown in FIG. 3, the laser writing unit 7 includes a unit case 38 for housing an optical system.
And the dustproof glass 3 attached to the opening of the case 38.
9 and a light-transmitting dust-proof member made of
The laser light L of No. 8 is emitted outside through the dustproof glass 39 and irradiates the surface of the image carrier 5.

The plurality of rollers 10 around which the intermediate transfer member 11 composed of an endless belt is wound have respective ends of the support shaft.
As shown in FIG. 4, the front side plate 92 and the rear side plate 93 opposed to the front side plate 92 are rotatably supported and integrally assembled, and the primary transfer device 12 is also detachably supported on both side plates 92 and 93. Have been. Thus, the front and rear side plates 9
Reference numerals 2 and 93 denote intermediate transfer members 11 via a plurality of rollers 10.
And a frame for supporting the intermediate transfer unit 94.
Is positioned relative to the image forming apparatus main body 1 and detachably set as described later.

As described above, the illustrated image forming apparatus includes:
An image carrier 5 on which an electrostatic latent image is formed, a developing device 8 for visualizing the electrostatic latent image formed on the image carrier 5 as a toner image, and after transferring the toner image to a transfer material A cleaning device 14 for removing transfer residual toner adhering to the surface of the image carrier. In this example, the toner image formed on the surface of the image carrier 5 is temporarily transferred to the surface of the intermediate transfer body 11 once. Then, since the toner image is configured to be transferred to the transfer paper P, as described above,
Constitute a transfer material on which a toner image is transferred from the surface of the image carrier 5. On the other hand, if the toner image on the surface of the image carrier is directly transferred to a final transfer material, for example, a transfer sheet, the toner image on the surface of the image carrier is transferred to the final transfer material. The transfer material.

Incidentally, the above-mentioned image forming apparatus should be configured so that maintenance work such as maintenance and inspection of the image carrier 5, the developing device 8 and the cleaning device 14 or replacement thereof can be easily performed.

Therefore, in the image forming apparatus of this embodiment,
As shown in FIG. 5, the image carrier 5 is rotatably held by the unit holder 40, and the charging charger 6 and the charge removing lamp 15 arranged around the image carrier 5 are also supported by the unit holder 40. The cleaning case 32 is detachably fixed to the unit holder 40, and the image carrier unit 41 is
Is configured. As described above, the image forming apparatus of this embodiment includes the image carrier unit 41 in which the image carrier 5 on which the toner image is formed is held by the unit holder 40.

The unit holder 40 has a top plate 42 made of, for example, a resin, and a front side plate 43 and a rear side plate 44 hanging downward at the front and rear ends thereof. The image carrier 5 is rotatably supported on the substrate. As shown in FIGS. 3 and 6, the top plate 42 has an opening 53 for guiding the laser beam emitted from the laser writing unit 7 to the surface of the image carrier.
The image carrier unit 41 configured as described above, together with the developing device 8 described above, is connected to the image forming apparatus main body 1 as shown in FIGS. It is detachably stored in the body 45. Normally, the operator performs an operation while facing the front of the image forming apparatus shown in FIG. 1, wherein the side closer to the operator is the near side or the front side, and the side far from the operator is the back side or the rear side. It is.

FIG. 6 shows a state in which the drawer 45 is connected to the image forming apparatus main body 1.
2 shows a state when the image carrier unit 41 is pulled out from the drawer body 45 to the front side. FIG.
8 shows a state when the image carrier unit 41 is mounted on the drawer 45, and FIG. 8 is a horizontal sectional view showing a state when the drawer 45 is pushed into the image forming apparatus main body 1 at the back side. FIG. 9 is a horizontal cross-sectional view after the drawer 45 has been loaded into a predetermined position of the image forming apparatus main body 1, and FIG.
FIG. 2 is a front view of the image forming apparatus after the image forming apparatus is loaded into the image forming apparatus main body 1, and shows a state when the inside of the image forming apparatus main body is removed by removing a front door (not shown).

As can be seen from these figures, the drawer 45
Is a front plate 46 on the near side, a rear plate 47 on the back side, and an appropriate number of stays for integrally connecting the side plates 46 and 47. The stays 48, 49, 50, and 51 are provided below the developing device 8 supported by the drawer 45.
There is a toner receiver 52 (FIG. 6) removably attached to. As shown in FIG. 7, in the image carrier unit 41, the top plate 42 of the unit holder 40 is the first plate.
And the drawer 45 placed on the second stays 48 and 49
It is supported detachably. As described above, the image forming apparatus of the present example includes the drawer 45 that detachably holds the image carrier unit 41 and is removably loaded into the image forming apparatus main body 1. The side plate 46 of the drawer 45 of this example,
47 and the first to fourth stays are made of a highly rigid material, for example, a metal plate.

As shown in FIGS. 8 and 9, the central shaft 31 of the developing device 8 is rotatably supported by a shaft holder 63 via a bearing at an end region on the back side. 63 is removably fitted in the hole 76 formed in the rear plate 47 of the drawer 45 in the axial direction with some play. The front end of the central shaft 31 is a bearing 6
4, the front side plate 46 of the drawer 45 is rotatably supported by the drawer 45, whereby the front portion of the developing device 8 is correctly positioned with respect to the drawer 45. Further, a knob 65 is detachably fixed to the end of the central shaft on the front side of the front side plate 46. 8 and 9, the black developing device 8BK
Developing roller 9BK and first and second conveying screws 2
7BK and 28BK are shown assembled on the side plates 24 and 24A and the support 25, but other developing units are not shown.

With the drawer body 45 pulled out to the front side as shown in FIG. 6, the upper developing device, in the example shown in the figure, the black developing device 8BK is removed from the support 25, or is removed from the support 25. Can be attached to Support 2
By rotating 5, any one of the developing devices can be positioned on the upper side, the developing device can be lifted upward, and the developing device can be detached from the support 25 or can be mounted thereon.

As shown in FIGS. 8, 9 and 11, the first
Notches 54 are formed at predetermined intervals in the third stays 48 and 50, and small-diameter necks of locking pins 57 and 58 provided on movable guide rails 55 and 56 are formed in these notches 54. The drawer 45 is supported by the movable guide rails 55 and 56. These movable guide rails 55 and 56 are attached to the image forming apparatus main body 1.
Are slidably fitted to the fixed guide rails 61 and 62 fixed to the front side plate 59 and the rear side plate 60, respectively. In this way, the drawer body 45 is supported so as to be able to be pulled out toward the image forming apparatus main body 1 toward the front side.

As described above, the first and third stays 48,
The notch 54 formed in the movable guide rails 55,5
The pull-out body 45 is supported by detachably engaging with the locking pins 57, 58 provided on the pull-out body 6. If the pull-out body 45 is pulled out to the near side, the pull-out body 45 is easily lifted upward. Can be removed from the movable guide rails 55 and 56.

When the drawer 45 is pushed into the inner side of the image forming apparatus main body 1 and set at a predetermined position on the image forming apparatus main body 1 as described later, the drawer 45 is engaged with the notch 54 as shown in FIG. A small gap δ is provided between the small diameter necks of the pins 57 and 58. When the drawer 45 is positioned with respect to the image forming apparatus main body 1, the gap δ is formed as described above. Can be positioned with respect to

On the other hand, as shown in FIGS. 8 and 9, the image carrier 5 has a cylindrical carrier body 66 having a photosensitive layer on the surface.
And a flange member 6 fixed to each longitudinal end thereof
7 and 68, and annular flanges 67A and 68A protruding from the respective flange members 67 and 68 have annular grooves 6 formed in the front and rear side plates 43 and 44 of the unit holder 40.
9, 70 are rotatably fitted with some play. Thus, the image carrier 5 is moved to the unit holder 40.
It is rotatably assembled to Further, the image forming apparatus main body 1
A drive shaft holder 71 is fixed to the rear side plate 60 at the back side of the drive shaft, and a drive shaft 72 is inserted through a center hole of the drive shaft holder 71.
2 is rotatably supported by the drive shaft holder 71 via a plurality of rolling bearings 95, 95A.

As shown in FIG. 8, the image carrier unit 41
When the operator pushes the drawer 45 in the inner side of the image forming apparatus main body 1, that is, in the direction of arrow C in FIG.
As shown in (1), the distal end of the drive shaft 72 enters the center hole of the slide bearing 73 fixed to the rear plate 47 of the drawer 45. Further, a front end of the drive shaft 72 is fitted into a rear end of the image carrier 5, in the illustrated example, a center hole 74 formed in a flange member 68 on the back side, and a joint 75 fixed to the drive shaft 72. Engages with an engagement surface 96 (FIG. 8) formed on a portion of the rear flange member 68 adjacent to the center hole 74.

The joint 75 has a tapered surface whose diameter is reduced toward the near side of the image forming apparatus main body 1, and a large number of teeth arranged in the circumferential direction are formed on the tapered surface. The engaging surface 96 is formed into a tapered surface shape complementary to the tapered surface of the joint 75, and a large number of teeth arranged in the circumferential direction are formed on the peripheral surface thereof. Are engaged with each other in such a manner that their teeth are in mesh with each other and cannot rotate relative to each other. As a result, the rear end of the image carrier 5 on the far side is positioned concentrically with respect to the drive shaft 72.

At this time, the cylindrical boss 71A of the drive shaft holder 71 fits into the center hole of the slide bearing 73 without rattling. At the same time, the outer race outer peripheral surface of one rolling bearing 95A of the pair of rolling bearings rotatably supporting the drive shaft 72 on the drive shaft holder 71 rattles in a hole 70A formed in the rear plate 44 of the unit holder 40. Mating without. Thereby, the image carrier unit 4
1 is positioned on the far side.

As described above, the image forming apparatus of this embodiment includes the drive shaft 72 for driving the image carrier 5 and the drive shaft 7.
2 is rotatably supported, and includes a drive shaft holder 71 fixed to the rear side plate 60 on the back side of the image forming apparatus main body 1.

On the other hand, as shown in FIG. 9, the rear end of the central shaft 31 of the developing device 8 is
, Which is rotatably fitted to the bearing 77 provided on the image forming apparatus without rattling.

As described above, the slide bearing 73 on the back side of the drawer 45 is fitted into the boss 71A of the drive shaft holder 71,
When the center shaft 31 of the developing device 8 is fitted to the bearing 77 of the image forming apparatus main body 1, the rear side of the drawer 45 is positioned with respect to the image forming apparatus main body 1.

Further, the drawer 45 is connected to the image forming apparatus main body 1.
6 and 10, positioning holes 78 formed in the front plate 46 of the drawer body 45 as shown in FIGS.
78A are fitted into positioning pins 79, 79A projecting from the front plate 59 of the image forming apparatus main body 1, respectively, whereby the near side of the drawer 45 is positioned with respect to the image forming apparatus main body 1.

When the drawer 45 is loaded at a predetermined position in the image forming apparatus main body 1 as described above, the inner side and the nearer side of the drawer 45, that is, the whole thereof, are positioned with respect to the image forming apparatus main body 1. You. Slide bearing 73, drive shaft holder 71 to which this is detachably fitted, central shaft 3 of developing device 8
1. Bearing 77 to which this is detachably fitted, positioning hole 7
8, 78A, and positioning pins 79, 79A to which they are detachably fitted, push the drawer 45 into a predetermined position of the image forming apparatus main body 1 and load the drawer 45 into the image forming apparatus main body 1. It constitutes an example of a positioning means for positioning with respect to. Since the developing device 8 is also correctly positioned with respect to the image forming apparatus main body 1, the distance between the center of the rotary developing device 8 and the center of the image carrier 5 is correctly defined.

After the drawer 45 has been positioned with respect to the image forming apparatus main body 1, the operator moves the tip of the driven shaft 81 shown in FIGS. 8 and 9 as shown in FIG. Of the flange member 67 on the near side, that is, the center hole 80 formed in the center of the flange member 67 on the near side. At this time, the driven shaft 81
And the center hole 80 are in frictional engagement, and the relative rotation of the driven shaft 81 and the flange member 67 is prohibited. The driven shaft 81 is rotatable in the center hole of the driven shaft holder 82 via the rolling bearings 13 and 13A, but is fitted in the axial direction of the driven shaft holder 82 without any backlash.

The driven shaft 81 is connected to the flange member 6 as described above.
7 when inserted into the center hole 80 of the front side plate 4
6 and a hole 40A formed in the front plate 43 on the front side of the unit holder 40, the driven shaft holder 8
2 fits. In this manner, the front end of the image carrier 5 and the front side of the image carrier unit 41 are in contact with the image forming apparatus main body 1.
Is positioned with respect to the drawer body 45 already positioned with respect to. The image carrier 5, its drive shaft 72 and its driven shaft 81 are correctly positioned concentrically.

As described above, the image forming apparatus according to the present embodiment includes the driven shaft 81 which is non-rotatably fitted to the front end on the front side of the image carrier 5, in the illustrated example, the front flange member 67. In a state where the driven shaft 81 is rotatably supported and the drawer 45 is pushed into the back side and is loaded at a predetermined position of the image forming apparatus main body 1, the drawer 45 and the unit holder 40 of the image carrier unit 41 are attached to the drawer 45. Holes 91 and 40 formed respectively
And a driven shaft that positions the front side of the unit holder 40 with respect to the drawer 45 while positioning the front end of the image carrier 5 with respect to the drawer 45 via the driven shaft 81. And a holder 82.

The driven shaft 81 is provided with a compression coil spring 81A wound around the driven shaft 81 so as to rotate together with the driven shaft 81. As shown in FIG. 9, the driven shaft 81 is fitted into the center hole 80 of the flange member 67 of the image carrier 5, and the driven shaft holder 82 is fixed to the image forming apparatus main body 1 via a fixing member 97 as described later. When fixed, the spring 81A is located between the flange member 67 and the inner race of the rolling bearing 13 and compressed,
Thereby, the image carrier 5 is pressed to the back side. In this way, the tapered engaging surface 96 formed on the rear flange member 68 and the tapered surface of the joint 75 are firmly engaged, and the relative rotation between them is reliably prohibited.

As described above, in the image forming apparatus of the present embodiment, when the drawer 45 is pushed to the rear side and loaded at a predetermined position of the main body 1 of the image forming apparatus, the rear end of the image carrier 5 is In the example shown in the figure, an engagement means for engaging the rear flange member 68 and the drive shaft 72 so that they cannot rotate relative to each other, and for positioning the rear end of the image carrier 5 concentrically with respect to the drive shaft 72. In the example shown in the figure, the engagement means is fixed to the drive shaft 72 and has a tapered surface 75 whose diameter is reduced toward the front side of the image forming apparatus main body 1. An engagement surface 96 formed at the rear end of the body 5 and in which the tapered surface of the joint 75 engages, is wound around the driven shaft 81 so as to rotate with the driven shaft 81, and the image carrier 5 is moved backward. Press to engage the engaging surface 96 and the tapered surface of the joint 75 so that they cannot rotate relative to each other. It is provided with a spring 81A to. Thus, with a simple configuration, the rear end of the image carrier on the far side is reliably positioned with respect to the drive shaft 72,
Both can be reliably engaged.

After the drawer 45 is positioned with respect to the image forming apparatus main body 1, the drawer 45 is moved to the image forming apparatus main body 1.
The image carrier 5 is securely attached to the image forming apparatus main body 1 so that the image carrier 5 does not separate from the image forming apparatus main body 1. Such fixing can be performed by appropriate means. In the illustrated example, the fixing is performed by a fixing member 97 described below.

As shown in FIGS. 8 to 10, a fixed member 97 made of a plate material generally called a face plate is firmly fixed to the driven shaft holder 82 by, for example, screws (not shown). As described above, the driven shaft 81 is fitted into the center hole 80 of the image carrier 5 and the driven shaft holder 82
Are fitted into the holes 91 and 40A. At this time, as shown in FIG. 10, the positioning pins 98 projecting from the front side plate 59 of the image forming apparatus main body 1 are fitted with the elongated holes 99 formed in the fixing member 97. Is fitted. Thereby, the fixing member 97 is correctly positioned with respect to the image forming apparatus main body 1. Therefore, the fixing member 97 is connected to the screws 100, 100 shown in FIG.
A, 100B, the front side plate 5 of the image forming apparatus main body 1
9 and the front plate 46 of the drawer 45 are firmly fixed. In this way, the components such as the image carrier 5 and the drawer 45 are correctly positioned with respect to the image forming apparatus main body 1 and assembled.

As described above, in the image forming apparatus of this embodiment, the driven shaft 81 is fixed to the driven shaft holder 82 and the driven shaft 81 is attached to the front end of the image carrier 5 (the front flange member 67 in the illustrated example). And the driven shaft holder 82 is
And a fixing member 97 fixed to the front side plate 59 of the image forming apparatus main body 1 in a state where the fixing member 97 is fitted in the holes 91 and 40A of the unit holder 40, respectively. Thus, the image carrier 5 and the drawer 45 can be securely assembled to the image forming apparatus main body 1 by a simple operation.

When the image forming operation is started in the above state, the pulley 8 fixed to the drive shaft 72 as shown in FIG.
3 is driven to rotate by a driving device (not shown) via a belt (not shown) and other transmission elements wound therearound, and the rotation is transmitted to the image carrier 5 so that the image carrier 5 is rotated. Rotate. At this time, the driven shaft 81 also rotates together with the image carrier 5. Further, the developing device 8 and each element thereof also
The image forming operation described above is executed by being driven as described above by a driving device (not shown). At this time, the flywheel 101 is fixed to the drive shaft 72 as shown in FIGS.
Can be stably rotated, and the respective toner images can be transferred to the intermediate transfer member 11 without causing a positional shift of the toner images of the respective colors formed on the surface thereof.

Here, when it becomes necessary to remove the image carrier unit 41 and the developing unit, the operation of the image forming apparatus is stopped and the screws 100, 100A, 1 shown in FIG.
9B, the fixing member 97, the driven shaft holder 82, and the driven shaft 81 are separated from the image forming apparatus main body 1 as shown in FIG. 8, and the drawer 45 is moved toward the front side, that is, the arrow B in FIG.
Then, the drawer 45 is stopped at the position shown in FIG. 6 by a stopper (not shown). Thus, the image carrier unit 41 and a desired developing device can be lifted upward and removed from the drawer 45. By removing the knob 65, the bearing 64, and the shaft holder 63 from the central shaft 31 of the developing device 8, the entire developing device 8 can be removed from the drawer 45.

As described above, the image carrier unit 41 is detachably held, and the drawer 45 holding the developing device 8 is detachably attached to the image forming apparatus main body 1. 5 together with the unit holder 40
It can be easily taken out or set.
Further, in this example, the developing device 8 and its respective developing devices are also connected to the drawer 45.
Can be easily detached from the drawer 45 or set. The maintenance work can be easily performed while the operator stands on the front side or the side of the drawer body 45 without taking an excessive posture.

A unit holder 40 and a drawer 45 are positioned around the image carrier 5, and the shaft for supporting and positioning the image carrier 5 is a drive shaft 72 and a driven shaft 81. However, since the image carrier is divided into two parts, the image carrier can be correctly positioned with respect to the image forming apparatus main body 1 with a simple configuration. Moreover, the overall weight can be reduced as compared with the case where the drive shaft 72 and the driven shaft 81 are integrated into one shaft.

If the driven shaft and the drive shaft are integrated into a single shaft, when the shaft is assembled to the image forming apparatus main body, the overall length of the shaft becomes longer. It is not easy to increase body position accuracy. In addition, if the flywheel is fixed to this single shaft, the weight tends to cause the front side of the shaft to be lifted upward, so that when the drawer is pushed backward, the image carrier does not enter the shaft properly. There is a risk. In order to prevent such a problem, a large cost is required for fixing the shaft. Further, if a flywheel is provided on the shaft, it is necessary to increase the diameter of the shaft in order to securely support the flywheel. However, if the length of the shaft is one, the weight is further increased and the cost is increased. To rise.

By dividing the shaft into a drive shaft 72 and a driven shaft 81 as in the illustrated example, the above-mentioned problem can be avoided.

As shown in FIGS. 8 and 9, the drive shaft 72 is provided with rolling bearings 95, 9 made of, for example, ball bearings.
The outer races of the rolling bearings 95 and 95A are press-fitted and fixed to the driving shaft holder 71, and the inner races of the rolling bearings 95 and 95A are fixed. Is press-fitted into the drive shaft 72 and fixed, whereby the drive shaft 72 can be integrally assembled to the drive shaft holder 71 via the rolling bearings 95 and 95A, and the play between the drive shaft 72 and the drive shaft holder 71 can be adjusted. And the positional accuracy of the image carrier 5 can be further improved.

Similarly, the joint 75 is press-fitted into the drive shaft 72 and fixed, and the rolling bearings (for example, ball bearings) 13, 13 are provided between the driven shaft 81 and the driven shaft holder 82.
By pressing the outer race A into the driven shaft holder 82 and fixing it, and pressing the inner race into the driven shaft 81 and fixing it, the positional accuracy of the image carrier can be reliably improved.

Further, as described above, a hole 70A is formed in the rear plate 44 on the back side of the unit holder 40 of the image carrier unit 41, and the hole 70A connects the drive shaft 72 to the drive shaft 72. The image bearing member has a simple configuration by being fitted to an outer race of a rolling bearing 95A for rotatably supporting the holder 71 and positioning the rear plate 44 of the unit holder 40 with respect to the image forming apparatus main body 1. The unit 41 can be positioned on the image forming apparatus main body 1.

As described above with reference to FIG. 4, the image forming apparatus of this embodiment includes an intermediate transfer member 11 for transferring a toner image formed on an image carrier, and a frame for supporting the intermediate transfer member. The intermediate transfer unit 94 is provided, and the intermediate transfer unit 94 can also be pulled out toward the front side of the image forming apparatus main body 1 or pushed into the back side to be loaded. At this time, as shown in FIG. 4, the front plate 92 and the rear plate 93 constituting the frame each have an appropriate number of positioning pins 102, 102 in the illustrated example.
A; 103, 103A are protruded, and the intermediate transfer unit 9
4 is pushed into the rear side of the image forming apparatus main body 1, the positioning pins 103, 103A on the rear side are fitted into positioning holes (not shown) formed in the rear plate 60 of the image forming apparatus main body 1, respectively. The back side of the intermediate transfer unit 94 is positioned with respect to the image forming apparatus main body 1.

After the intermediate transfer unit 94 is inserted into the image forming apparatus main body 1 as described above, the driven shaft holder 82 is
The fixing member 97 is attached to the main body 1 of the image forming apparatus as described above by fitting the drawer body 45 into the holes 91 and 40A of the unit holder 40. At this time, the fixing member 97 projects to the front side plate 92 of the intermediate transfer unit 94. Positioning pins 102, 102 provided
A is fitted into each of the positioning holes 104 and 104A formed in the fixing member 97 as shown in FIG. As a result, the intermediate transfer unit 94 is correctly positioned with respect to the image forming apparatus main body 1. In this state, as described above, the intermediate transfer unit 94 is fixed to the image forming apparatus main body 1 by the screws 100, 100A, and 100B.
As described above, the fixed member 97 engages with the frame of the intermediate transfer unit 94 in a state where the driven shaft holder 82 is fitted into the drawers 45 and the holes 91 and 40A of the unit holder 40, and the intermediate transfer body 11 Is positioned with respect to the image forming apparatus main body 1.

According to the above configuration, the fixing member 97 fixes the drawer 45 to the image forming apparatus main body 1 and also functions as a positioning plate for positioning the intermediate transfer unit 94 with respect to the image forming apparatus main body 1, thereby simplifying the operation. The intermediate transfer unit 94 can be positioned with a simple configuration and with a simple operation. Just by fixing the fixing member 97 to the front side plate 59 of the image forming apparatus main body 1, the taper surface of the joint 75 and the engaging surface 96 of the image carrier 5 are simultaneously pressed, and the image carrier 5 and the image carrier are also pressed. The positioning of the unit 41 is performed, so that all operations can be performed extremely easily.

In the cleaning device 14 described above with reference to FIG. 3, the cleaning case 32 is fixed to the unit holder 40, and the cleaning device 14 is attached to the drawer 45 together with the image carrier 5. It is attached and detached. Therefore, when the image carrier unit 41 is detached from the drawer 45 or attached, the opening 35 of the cleaning case 32 is covered by the outer peripheral surface of the image carrier 5 as shown in FIG. Therefore, a large amount of toner in the cleaning case 32 does not spill outside through the opening 35. In this way, the image carrier 5 and the cleaning device 14 are not stained with the toner around the image forming apparatus.
In addition, maintenance work for the developing device 8 can be performed efficiently.

Further, in the image forming apparatus of this embodiment,
As described below, the image carrier 5 and the cleaning device 1
4 is detachably assembled to the unit holder 40, removes the image carrier 5 and the cleaning device 14 from the unit holder 40, and cleans the image carrier 5 and the cleaning blade 33, and replaces them. It is configured to be able to.

As described above, the drawer 45 is pulled out to the front side of the image forming apparatus main body 1 and stopped at the drawn position, and then the image carrier unit 41 is lifted up and removed. Next, the image carrier unit 41 is mounted on a mounting surface such as a desk, with the top plate 42 facing down, while being rotated by 180 ° as shown in FIG.

Here, each side plate 4 of the unit holder 40
The fixed portions 43A and 44A are integrally formed on the top plate 42, and the other movable portions 43B and 44B are connected to a pivot pin 84.
Are pivotally attached to the fixed portions 43A, 44A via
Normally, the movable portions 43B and 44B are fixed to the fixed portions 43A and 44A by two screws 85.

Therefore, as described above, the image carrier unit 4
1 is placed on a desk, the screw 85 is removed, and the movable part 43 is removed.
B and 44B are rotated as shown in FIG. As a result, the image carrier 5 is exposed to the outside, and the image carrier 5 can be removed from the unit holder 40 by lifting it up as it is.

As shown in FIG. 14, the cleaning device 14 can be removed from the unit holder 40 by removing another screw 86. When the image carrier 5 is removed from the unit holder 40 or the cleaning device 14 is removed from the unit holder 40 as described above, the opening 35 (FIG. 3) of the cleaning case 32 is opened.
At this time, since the work can be performed by placing the unit holder 40 on a desk or the like, the work can be performed carefully and the opening 3
5 can be prevented from spilling out.

Further, as shown in FIGS. 5 and 6, a hole 89 for attaching and detaching the charging charger 6 (FIG. 3) is formed in the side plate 43 of the unit holder 40, and the charging charger 6 is pulled out through the hole 89. You can also. FIGS. 13 and 14 show a state after the charging charger 6 has been pulled out.

The cleaning device 14 and the image carrier 5 are assembled to the unit holder 40 by the operation reverse to the above-mentioned operation.
, And the drawer 45 is pushed into the image forming apparatus main body 1 to position each element at a predetermined position as described above.

As shown in FIG. 6, the drawer 45 is pulled out from the image forming apparatus main body 1 to the front side thereof and stopped, and the image carrier unit 41 is pulled out while the developing device 8 is stored in the drawer 45. The image carrier 5 and the developing device 8 occupying the developing position can be detached from or attached to the developing device 8 when the image carrier unit 41 and the developing device 8 are both housed in the drawer 45 and set. Since the developing rollers are opposed to each other with a very small gap of, for example, 1 mm or less, when the image carrier unit 41 is attached to and detached from the drawer 45 while the developing device 8 is set on the drawer 45, the image carrier The surface of the image bearing member 5 may be scratched by an element of the developing device, in particular, a developing roller. In order to prevent such a problem, the image forming apparatus of the present embodiment is configured as follows.

FIG. 7 shows a state in which the upper portion 87 of the unit holder 40 near the developing device 8 is supported on the second stay 49.
The horizontal portion 49A on which the portion 87 is placed as shown in FIG.
And a vertical portion 49B that rises substantially perpendicularly to the horizontal portion 49A. The vertical portion 49B is provided with a guide piece 88 formed by cutting and raising the stay itself. At an angle θ larger than 0 ° and smaller than 90 ° with respect to 49B, it projects obliquely downward toward the portion 87 of the unit holder 40.

Here, the first and second stays 48, 49
When the image carrier unit 41 supported by the unit holder 40 is lifted upward to remove the image carrier unit 41 supported from the drawer 45, the portion 87 of the unit holder 40 becomes a guide piece 88.
, The image carrier unit 41 is
7 around the pivots in the direction indicated by the arrow S ₁ in FIG. The image carrier unit 41 rotates in a direction in which the image carrier 5 of the image carrier unit 41 moves away from the developing device 8. In state where the image carrier 5 away from the developing device 8 to move in a direction away from the developing device 8 to indicate an image bearing member unit 41 in the arrow S ₂ in FIG. 7, portions 87 of the unit holder 40 the by removing from the guide piece 88, it can be lifted upwardly as shown the image carrier unit 41 by the arrows S _3.

As described above, when removing the image carrier unit 41 from the drawer 45, if the image carrier unit 41 is not moved so that the image carrier 5 moves away from the developing device 8, the image carrier unit 41 is removed. The image carrier 5 is so configured that it cannot be detached from the drawer body 45. Therefore, during this removal operation, the image carrier 5 strongly hits the developing roller of the developing device 8 due to the carelessness of the operator, and the surface of the image carrier is damaged. Can be prevented.

As described above, in the image forming apparatus of this embodiment, when the image carrier unit 41 is detached from the drawer 45, the image carrier unit 41 is moved away from the developing device 8 held by the drawer 45. A guide for guiding the image carrier unit 41 is provided on the drawer 45 so as to move to the horizontal direction. In the illustrated example, the guide is provided on the horizontal portion 49A of the second stay 49 and the vertical portion 49B. The guide piece 88 forms the guide.

Further, when the image carrier unit 41 is lifted so as to remove the image carrier unit 41 from the drawer 45, the image carrier unit 41
The image carrier unit 41 is guided such that a lower portion thereof rotates around a portion 87 close to the developing device in a direction away from the developing device 8.

As shown in FIGS. 3, 5, and 7,
The front side plate 43 and the rear side plate 44 of the unit holder 40 are formed to be slightly larger than the outer peripheral surface of the image carrier 5, and that portion constitutes a projecting portion 90. That is, the unit holder 40 has the projecting portion 90 projecting outward from the outer peripheral surface of the image carrier 5. Moreover, the unit holder 40
Has a front plate 43 and a rear plate 44 that support each end of the image carrier 5 in the axial direction, and a peripheral portion extending along the outer peripheral surface of the image carrier of the side plates 43 and 44 has an image carrier. 5 protrudes outward from the outer peripheral surface, and the protruding peripheral portion forms a protruding portion 90.

According to the above configuration, the developing device 8 is connected to the drawer 4
5, the image carrier unit 41 is pulled out of the drawer 4
5 or when the image carrier unit 41 is attached to the drawer 45, even if the image carrier unit 41 is not parallel to the developing device 8, the projecting portion of the unit holder 40. Although the image 90 may hit an element of the developing device 8, for example, its developing roller, the image carrier 5 does not hit the developing roller, thereby preventing a problem that the surface of the image carrier is scratched.

After the image carrier unit 41 is detached from the drawer 45, the operator mistakenly turns the top plate 42 upward and the image carrier 5 downward, and places the image carrier 5 on a mounting surface such as a desk. Even if the image carrier 5 is placed on the surface of the image carrier 5, the projecting portion 90 only hits the surface of the image carrier 5 and the surface of the image carrier 5 does not contact the surface of the image carrier 5. Failures can be prevented.

The above-described configuration of the guide and the protruding portion 90 can be achieved by using only one of them.
Although the occurrence of scratches on the surface of the image carrier can be effectively suppressed, the use of both the configurations can more effectively prevent the surface of the image carrier from being scratched.

The present invention is not limited to a color image forming apparatus.
It can be widely applied to an image forming apparatus for forming a single-color visible image, and an image forming apparatus such as a printer, a facsimile or a multifunction machine. The present invention can be widely applied to an image forming apparatus for transferring an original image onto a final transfer material, and an image forming apparatus using an exposure apparatus for forming an image of a document directly on the surface of an image carrier.

[0091]

According to the image forming apparatus of the first aspect, the image carrier is assembled to the unit holder to form the image carrier unit, and the image carrier unit is moved relative to the image forming apparatus main body. Since the image carrier unit is mounted on the drawer that is attached so as to be able to be pulled out, the image carrier unit can be easily attached and detached, and the maintainability can be improved. Moreover, the image carrier can be correctly positioned with respect to the image forming apparatus main body with a simple configuration and a simple operation.

According to the image forming apparatus of the second aspect,
The play between the drive shaft and the drive shaft holder can be eliminated, and the positional accuracy of the image carrier can be further improved.

According to the image forming apparatus of the third aspect,
With a simple configuration, the image carrier unit can be correctly positioned with respect to the image forming apparatus main body.

According to the image forming apparatus of the fourth aspect,
With a simple configuration, the driven shaft holder and the drawer can be fixed to the image forming apparatus main body, and the image carrier can be correctly positioned and assembled with the image forming apparatus main body.

According to the image forming apparatus of the fifth aspect,
The fixing member serves as a positioning member for the intermediate transfer unit, and a dedicated member for positioning the intermediate transfer unit can be omitted, so that the configuration of the image forming apparatus can be simplified and the cost can be reduced.

According to the image forming apparatus of the sixth aspect,
With a simple configuration, the image carrier can be reliably connected to the drive shaft, and the rotation of the drive shaft can be correctly transmitted to the image carrier.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the internal structure of an image forming apparatus from the front side.

FIG. 2 is an enlarged sectional view showing details of a developing device shown in FIG.

FIG. 3 is a cross-sectional view illustrating an image carrier, a cleaning device, a unit holder, and a laser writing unit that constitute the image carrier unit.

FIG. 4 is a perspective view of an intermediate transfer unit.

FIG. 5 is a perspective view of an image carrier unit.

FIG. 6 is a perspective view showing a state in which the drawer is pulled out to the near side of the image forming apparatus main body, and the image carrier unit and one developing device are removed from the drawer;

FIG. 7 is a partial cross-sectional view schematically showing a relative positional relationship between a drawer and an image carrier unit supported by the drawer.

FIG. 8 is a horizontal cross-sectional view when the drawer is pushed into the inner side of the image forming apparatus main body.

FIG. 9 is a horizontal sectional view after the drawer is set in the image forming apparatus main body.

FIG. 10 is a diagram illustrating a state after the drawer has been set in the image forming apparatus main body, as viewed from the front side of the front side plate of the image forming apparatus main body.

FIG. 11 is a diagram illustrating an assembled state of first and third stays and a movable guide rail.

FIG. 12 is a perspective view illustrating a state in which the image carrier unit removed from the drawer is placed on the placement surface.

FIG. 13 is a perspective view showing a state when the image carrier is removed from the unit holder.

FIG. 14 is a perspective view showing how the cleaning device is removed from the unit holder.

FIG. 15 is a perspective view illustrating a guide piece provided on a second stay.

[Explanation of symbols]

 1 Image Forming Apparatus Main Body 5 Image Carrier 11 Intermediate Transfer Body 40 Unit Holder 40A Hole 41 Image Carrier Unit 44 Rear Side Plate 45 Extractor 59 Front Side Plate 60 Rear Side Plate 70A Hole 71 Drive Shaft Holder 72 Drive Shaft 75 Joint 81 Follower Shaft 81A Spring 82 Follower shaft holder 91 Hole 94 Intermediate transfer unit 95 Rolling bearing 95A Rolling bearing 96 Engagement surface 97 Fixing member

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuyuki Sugihara 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Kenji Maeda 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C061 AP03 AP04 AQ06 AR01 AS02 BB10 BB12 CD03 CF03 2H071 BA04 BA13 BA16 BA19 BA29 BA36 CA05 DA13 DA15 DA26

Claims (6)

[Claims] An image carrier unit having an image carrier having a toner image formed on a surface thereof held in a unit holder, the image carrier unit being detachably held, and being drawable to an image forming apparatus main body. And a drive shaft for driving the image carrier, a drive shaft holder rotatably supporting the drive shaft, and fixed to a rear-side rear plate of the image forming apparatus main body. When the drawer is loaded at a predetermined position of the image forming apparatus main body, the rear end of the image carrier is engaged with the drive shaft so that they cannot rotate relative to each other, and the rear end of the image carrier is Engaging means for positioning the portion with respect to the drive shaft; positioning means for positioning the drawer with respect to the image forming apparatus main body when the drawer is loaded at a predetermined position of the image forming apparatus main body; Non-rotatably fitted to the front end on the near side of the body A driven shaft, which is rotatably supported on the driven shaft, and which is formed in the unit holder of the drawn-out member and the image carrier unit in a state where the drawn-out member is mounted at a predetermined position of the image forming apparatus main body. Fit into the hole,
An image forming apparatus comprising: a driven shaft holder that positions a front side of a unit holder with respect to a drawer and positions a front end of an image carrier with respect to the drawer via the driven shaft. 2. The drive shaft is rotatably supported by a drive shaft holder via a rolling bearing, an outer race of the rolling bearing is press-fitted into the drive shaft holder and fixed, and an inner race of the rolling bearing is mounted on the drive shaft. The image forming apparatus according to claim 1, wherein the image forming apparatus is press-fitted and fixed. 3. The rear plate of the unit holder is positioned with respect to the main body of the image forming apparatus by fitting a hole formed in a rear plate on the back side of the unit holder into an outer race of the rolling bearing. 3. The image forming apparatus according to 2. 4. While being fixed to a driven shaft holder,
A fixing member fixed to the front side plate of the image forming apparatus main body in a state where the driven shaft is fitted to the front end of the image carrier, and the driven shaft holder is fitted to the drawer and the hole of the unit holder, respectively. The image forming apparatus according to claim 1, further comprising: 5. An image forming apparatus, comprising: an intermediate transfer unit having an intermediate transfer body to which a toner image formed on an image carrier is transferred, and a frame supporting the intermediate transfer body. 5. The image forming apparatus according to claim 1, wherein the intermediate transfer body is engaged with a frame of the intermediate transfer body in a state where the intermediate transfer body is fitted into each hole of the body and the unit holder to position the intermediate transfer body with respect to the image forming apparatus main body. Image forming device. 6. A joint having a tapered surface fixed to the drive shaft and reduced in diameter toward the near side of the image forming apparatus main body, the engaging means being formed at a rear end of the image carrier. An engagement surface with which the tapered surface of the joint is engaged, and a driven shaft which is wound around the driven shaft so as to rotate together with the driven shaft, and presses the image carrier toward the back side, so that the tapered surface between the engagement surface and the joint is formed. The image forming apparatus according to any one of claims 1 to 5, further comprising a spring that engages the surface so that the surface cannot rotate relatively.