JP3583297B2 - Image forming device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus that forms a toner image on a surface of an image carrier and transfers the toner image to a transfer material.
[0002]
[Prior art]
An image forming apparatus of the above type configured as an electronic copying machine, a printer, a facsimile, or a multifunction peripheral having at least two of these functions has been conventionally known. In order to enhance the maintainability of the 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.
[0003]
By the way, an image carrier has a toner image formed on its surface. In order to improve the image quality of the toner image, it is necessary to position and set the image carrier with high precision with respect to the image forming apparatus main body. There is.
[0004]
However, as described above, an image carrier unit is configured by holding the image carrier in a unit holder, and is configured to be detachably housed in a drawer. Since each element of the drawer is present, when the drawer is pushed into the inner side of the image forming apparatus main body and is loaded into a predetermined position, the image carrier can be properly positioned with respect to the image forming apparatus main body. To construct, the structure becomes extremely complicated and the operation at this time becomes complicated. As described above, the adoption of the structure of the image carrier unit and the drawer that supports the image carrier unit improves the maintainability of the image forming apparatus.On the other hand, when the drawer is loaded in 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]
[Problems to be solved by the invention]
The present invention has been made based on the above-described novel recognition, and an object of the present invention is to adopt a configuration of an image carrier unit and a drawer that detachably holds the image carrier unit, and a simple configuration. Another 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]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image carrier unit formed by holding an image carrier having a toner image formed on a surface thereof in a unit holder, the image carrier unit being detachably held, and A drawer that is removably loaded into the body of the forming apparatus, a drive shaft for driving the image carrier, rotatably supports the drive shaft, and is fixed to a rear side plate on the back side of the body of the image forming apparatus. Drive shaft holder, and when the drawer is loaded at a predetermined position of the image forming apparatus main body, the rear end of the image carrier on the rear side and the drive shaft are engaged with each other such that they cannot rotate relative to each other, and Engaging means for positioning the rear end of the image carrier with respect to the drive shaft; and positioning 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. Means and a front end on the near side of the image carrier A driven shaft that fits in a non-rotatable manner, and a unit of the drawer and the image carrier unit in a state where the driven shaft is rotatably supported and the drawer is loaded at a predetermined position of the image forming apparatus main body. The front side of the image carrier is positioned with respect to the drawer via the driven shaft while the front side of the unit holder is positioned with respect to the drawer by fitting into the holes formed in the holders. An image forming apparatus including a driven shaft holder is proposed (claim 1).
[0007]
At this time, the drive shaft is rotatably supported on the drive shaft holder via a rolling bearing, the outer race of the rolling bearing is press-fitted into the drive shaft holder and fixed, and the inner race of the rolling bearing is press-fitted into the drive shaft. It is advantageous if it is fixed in a fixed manner.
[0008]
3. The image forming apparatus according to claim 2, wherein a hole formed in a rear plate on the back side of the unit holder is fitted into an outer race of the rolling bearing, and the rear plate of the unit holder is a main body of the image forming apparatus. (Claim 3).
[0009]
4. The image forming apparatus according to claim 1, wherein 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 holder is pulled out. It is advantageous to provide a fixing member that is fixed to the front side plate of the image forming apparatus main body while being fitted in the holes of the body and the unit holder, respectively.
[0010]
In addition, the above claims 4 5. The image forming apparatus according to claim 1, further comprising an intermediate transfer unit having an intermediate transfer body to which the toner image formed on the image carrier is transferred, and a frame that supports the intermediate transfer body, wherein the fixed member includes the driven shaft holder. It is advantageous that, in a state in which the intermediate transfer member is engaged with the frame of the intermediate transfer member in a state where the intermediate transfer member is fitted in each hole of the drawer and the unit holder, the intermediate transfer member is positioned with respect to the image forming apparatus main body ( Claim 5).
[0011]
Further, in the image forming apparatus according to any one of claims 1 to 5, the engagement means may include a tapered surface fixed to the drive shaft and reduced in diameter toward the front side of the image forming apparatus main body. A joint having an engagement surface formed at a rear end of the image carrier and engaging a tapered surface of the joint with the driven shaft so as to rotate with the driven shaft. Advantageously, there is provided a spring which presses to the side to engage the engaging surface and the tapered surface of the joint so that they cannot rotate relative to each other (claim 6).
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
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 to be made by the color copying machine, a document (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 is pressed. As a result, the reading optical system 4 operates, and the document image is read.
[0014]
On the other hand, an image carrier 5 is arranged inside the image forming apparatus main body 1, and in the illustrated example, an image carrier composed of a drum-shaped photoconductor 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 a discharging action of a charging charger 6 composed of a corona discharger, which is an example of a charging device. Is charged.
[0015]
Above the image carrier 5, a laser writing unit 7, which is an example of an exposure device, is arranged. From the writing unit 7, a laser beam L light-modulated according to image information read by the reading optical system 4 is output. The laser light L is emitted, and is irradiated on 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.
[0016]
A rotary developing device 8, which is an example of a developing device, is disposed adjacent to the image carrier 5. The developing device 8 includes a black developing device 8BK, a cyan developing device 8C, a magenta developing device 8M, and a yellow developing device 8Y. have. Each developing device has developing rollers 9BK, 9C, 9M, and 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, carries an image. The first electrostatic latent image is visualized as a black toner image by a black developer (not shown) occupying a developing position facing the body and carried by the developing roller 9BK. 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.
[0017]
On the other hand, 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 the surface of the image carrier, and the intermediate transfer member 11 is driven to rotate in the direction of the arrow. However, a part of the surface abuts on the surface of the image carrier, and at the contact portion, moves in the same direction as the moving direction of the surface of the image carrier at the same linear velocity as the linear velocity of the surface of the image carrier. 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 this example, the intermediate transfer member 11 constitutes a transfer material on which the toner image on the surface of the image carrier is transferred.
[0018]
The transfer residual toner adhering to the surface of the image carrier after transferring the toner image to the intermediate transfer body 11 is removed by the cleaning device 14, and then the surface of the image carrier is irradiated with light by the neutralization lamp 15 to change its surface potential. Is reduced to the reference value.
[0019]
Next, a second electrostatic latent image is formed on the surface of the image carrier in exactly the same manner as described above. At this time, the rotation of the developing device 8 causes the second developing device, in this example, the cyan developing device 8C, to occupy 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 from above the previously transferred black toner image in a superimposed state. The surface of the image carrier after the transfer of the toner image is cleaned by the cleaning device 14 and is subjected to the charge removing operation by the charge removing lamp 15 as in the previous operation.
[0020]
Further, in exactly the same manner as described above, the third and fourth electrostatic latent images sequentially formed on the surface of the image bearing member are separated from the developing rollers 9M and 9M of the magenta developing device 8M and the yellow developing device 8Y of the developing device 8, respectively. The magenta developer and the yellow developer carried on 9Y sequentially visualize the magenta toner image and the yellow toner image as a magenta toner image and a yellow toner image, and these are superimposed on the intermediate transfer member surface from above the previously transferred toner image. The images are sequentially transferred in the state of being pressed. In this manner, four color toner images are formed on the surface of the intermediate transfer member in a superimposed state.
[0021]
On the other hand, a secondary transfer device 18 composed of, for example, a corona discharger is disposed to face the intermediate transfer body 11, and a paper feed device 16 disposed below the transfer device 18 transfers a transfer paper as an example of a final transfer material. 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 body 11 at a timing matching with the toner image on the intermediate transfer body 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 superimposed 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.
[0022]
The transfer paper P on which the toner image has been transferred is carried while being carried on a conveyor belt 19, and when passing through the fixing device 20, the toner image on the transfer paper is fixed on the surface of the transfer paper by the action of heat and pressure. . Next, the transfer paper is discharged onto a discharge tray 21 outside the machine as final copy paper.
[0023]
The transfer residual toner adhered to the surface of the intermediate transfer member after transferring the toner image onto the transfer paper P 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 body 11 when the toner image on the intermediate transfer body 11 before being transferred passes through the cleaning member 23.
[0024]
FIG. 2 is a cross-sectional view showing details of the rotary developing device 8. The developing device 8 has a back side plate 24 and a front side plate 24A (see FIGS. 6, 8 and 9). The side plates 24, 24A are integrally connected by a support 25, and the above-described developing units 8BK, 8C, 8M, 8Y are detachably supported by the side plates 24, 24A and the support 25, respectively. . Each of the developing devices has a developing case 26BK, 26C, 26M, 26Y for accommodating a powdery developer (not shown), and has therein the aforementioned developing rollers 9BK, 9C, 9M, 9Y, One transport screw 27BK, 27C, 27M, 27Y and a second transport screw 28BK, 28C, 28M, 28Y are rotatably arranged, and doctor blades 29BK, 29C, 29M, 29Y are fixed to the respective developing cases. Are located.
[0025]
The developer in the developing case 26BK of the developing device 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 moved clockwise. Is carried and transported by the developing roller 9BK that rotates. At this time, the amount of developer conveyed by the doctor blade 29BK is regulated, and the regulated developer is carried between the developing roller 9BK and the image carrier 5, where the toner in the developer is electrostatically latent. The electrostatic latent image is electrostatically transferred to an image, and the electrostatic latent image is visualized as a toner image of a predetermined color.
[0026]
Further, toner cartridges 30BK, 30C, 30M, and 30Y are mounted on the respective developing devices, and toners of respective colors are supplied from the respective toner cartridges to the respective developing cases.
[0027]
In the developing device 8 described above, the support 25 is supported on the central shaft 31 so as not to rotate relatively, and the central shaft 31 is rotatably supported on the image forming apparatus main body 1 as described later. Is driven by a driving device (not shown), so that each developing device can occupy a developing position facing the image carrier 5.
[0028]
On the other hand, as shown in FIG. 3, the cleaning device 14 has a cleaning case 32 and a cleaning member for removing transfer residual toner on the surface of the image carrier. In the cleaning device 14 shown here, the base end is cleaned. A cleaning member 33 fixed to the case 32 and having a leading edge pressed against the surface of the image carrier; and a cleaning brush 34 disposed in the cleaning case 32 and rotatably supported by the case and driven to rotate. 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.
[0029]
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 flying out of the cleaning case through the opening 35.
[0030]
As shown in FIG. 3, the laser writing unit 7 has a unit case 38 for housing an optical system, and a light-transmitting dust-proof member made of dust-proof glass 39 attached to an opening of the case 38. The laser light L of the case 38 is emitted to the outside through the dustproof glass 39 and irradiates the surface of the image carrier 5.
[0031]
The plurality of rollers 10 around which the intermediate transfer member 11 formed of an endless belt is wound have respective ends of their support shafts rotatable on a front side plate 92 and a rear side plate 93 opposed thereto, as shown in FIG. The primary transfer device 12 is also detachably supported by the side plates 92 and 93. As described above, the front and rear side plates 92 and 93 constitute a frame that supports the intermediate transfer body 11 via the plurality of rollers 10, and these constitute an intermediate transfer unit 94. The intermediate transfer unit 94 will be described later. Is positioned with respect to the image forming apparatus main body 1 as described above and is detachably set.
[0032]
As described above, the illustrated image forming apparatus includes an image carrier 5 on which an electrostatic latent image is formed, and a developing device that visualizes the electrostatic latent image formed on the image carrier 5 as a toner image. And a cleaning device 14 for removing transfer residual toner attached to the surface of the image carrier after transferring the toner image to the transfer material. In this example, the toner image formed on the surface of the image carrier 5 is removed. Since the toner image is temporarily transferred to the surface of the intermediate transfer member 11 and then the toner image is transferred to the transfer paper P, the intermediate transfer member 11 is moved from the surface of the image carrier 5 as described above. It constitutes a transfer material on which a toner image is transferred. On the other hand, when the toner image on the surface of the image carrier is directly transferred to a final transfer material, for example, transfer paper, the toner image on the surface of the image carrier is transferred to the final transfer material. Transfer material.
[0033]
Incidentally, the above-described image forming apparatus should be configured to easily perform maintenance work such as maintenance and inspection of the image carrier 5, the developing device 8 and the cleaning device 14, or replacement thereof.
[0034]
Therefore, in the image forming apparatus of the present 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 static elimination lamp 15 arranged around the image carrier 5. Are also supported by the unit holder 40, and the cleaning case 32 of the cleaning device 14 is detachably fixed to the unit holder 40. These elements constitute an image carrier unit 41. 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.
[0035]
The unit holder 40 has a top plate 42 made of, for example, a resin, and a front plate 43 and a rear plate 44 hanging downward at the front and rear ends thereof. The body 5 is rotatably supported. As shown in FIGS. 3 and 6, the top plate 42 has an opening 53 for guiding the laser light 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 attached to the image forming apparatus main body 1 as shown in FIGS. It is removably stored in the body 45. Normally, an operator performs an operation while facing the front of the image forming apparatus shown in FIG. 1, in which case 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.
[0036]
FIG. 6 shows a state in which the drawer 45 is pulled out from the image forming apparatus main body 1 to the front side, and the image carrier unit 41 is taken out from the drawer 45. FIG. 7 is a horizontal cross-sectional view illustrating a state in which the image carrier unit 41 is mounted on the drawer 45, and FIG. 8 is a horizontal cross-sectional view illustrating a state in which the drawer 45 is pushed into the inner side of the image forming apparatus main body 1. is there. FIG. 9 is a horizontal cross-sectional view after the drawer 45 is loaded at a predetermined position of the image forming apparatus main body 1, and FIG. 10 is a front view of the image forming apparatus after the drawer 45 is loaded into the image forming apparatus main body 1. FIG. 3 is a view of the image forming apparatus when a front door (not shown) is removed and the inside of the image forming apparatus main body is viewed.
[0037]
As can be seen from these figures, the drawer body 45 has a front side plate 46 on the near side, a rear side plate 47 on the back side, and an appropriate number of stays for integrally connecting these side plates 46, 47. And four first to fourth stays 48, 49, 50, and 51 at the upper and lower sides of the center, and detachable from the drawer 45 below the developing device 8 supported by the drawer 45. Is located at the toner receiver 52 (FIG. 6). As shown in FIG. 7, the image carrier unit 41 has the top plate 42 of the unit holder 40 placed on the first and second stays 48 and 49 and is detachably supported by the drawer 45. As described above, the image forming apparatus of the present example includes the drawer 45 that detachably holds the image carrier unit 41 and that is removably loaded into the image forming apparatus main body 1. The side plates 46, 47 and the first to fourth stays of the drawer 45 of the present example are made of a highly rigid material, for example, a metal plate.
[0038]
As shown in FIGS. 8 and 9, the center 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. The drawer 45 is fitted in a hole 76 formed in the rear side plate 47 of the drawer 45 with a certain amount of play in an axially immovable manner and detachably. The front end of the central shaft 31 is rotatably supported by the front plate 46 of the drawer 45 via a bearing 64, so that the front portion of the developing device 8 is correctly positioned with respect to the drawer 45. Positioned. Further, a knob 65 is detachably fixed to the end of the central shaft on the front side of the front side plate 46. FIGS. 8 and 9 show a state in which the developing roller 9BK and the first and second transport screws 27BK and 28BK of the black developing device 8BK are assembled to the side plates 24 and 24A and the support 25. The illustration of the developing device is omitted.
[0039]
With the drawer body 45 pulled out to the front side as shown in FIG. 6, the developing device located above, that is, the black developing device 8BK in the illustrated example, is removed from the support 25 or is attached to the support 25. be able to. By rotating the support 25, 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 mounted.
[0040]
As shown in FIGS. 8, 9 and 11, cutouts 54 are formed at predetermined intervals in the first and third stays 48 and 50, and these cutouts 54 have movable guide rails 55 and 56. The small-diameter necks of the locking pins 57, 58 provided on the base are detachably engaged, whereby the drawer 45 is supported by the movable guide rails 55, 56. The movable guide rails 55 and 56 are slidably fitted to fixed guide rails 61 and 62 fixed to the front plate 59 and the rear plate 60 of the image forming apparatus main body 1, respectively. In this manner, the drawer body 45 is supported so as to be able to be pulled out toward the front side of the image forming apparatus main body 1.
[0041]
The notch 54 formed in the first and third stays 48, 50 as described above is detachably engaged with the locking pins 57, 58 provided on the movable guide rails 55, 56, so that the drawer body 45 is formed. , The drawer 45 can be easily lifted upward and removed from the movable guide rails 55 and 56 by pulling the drawer 45 toward the user.
[0042]
Further, when the drawer 45 is pushed into 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 notch 54 and the locking pin 57, as shown in FIG. A small gap δ is provided between the small-diameter neck portion 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, so that the drawer 45 can be positioned by the positioning means described later without any trouble. Can be positioned with respect to
[0043]
On the other hand, as shown in FIGS. 8 and 9, the image carrier 5 comprises a cylindrical carrier body 66 having a photosensitive layer on the surface, and flange members 67, 68 fixed to each longitudinal end. The annular flanges 67A, 68A protruding from the respective flange members 67, 68 are rotatably fitted to the annular grooves 69, 70 formed on the front and rear side plates 43, 44 of the unit holder 40 with some play. ing. Thus, the image carrier 5 is rotatably assembled to the unit holder 40. A drive shaft holder 71 is fixed to the rear side plate 60 on the back side of the image forming apparatus main body 1, and a drive shaft 72 is inserted into a center hole of the drive shaft holder 71. The drive shaft 72 is provided with a plurality of rolling bearings 95, 95 A. It is rotatably supported by the drive shaft holder 71 via the same.
[0044]
As shown in FIG. 8, in a state where the image carrier unit 41 and the developing device 8 are mounted on the drawer 45, the operator places the drawer 45 on the back side of the image forming apparatus main body 1, that is, the arrow C in FIG. As shown in FIG. 9, 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 as shown in FIG. Further, a joint 75 fixed to the drive shaft 72 by fitting the front end of the drive shaft 72 into the rear end of the image carrier 5, in the illustrated example, into a center hole 74 formed in the flange member 68 on the back side. Engages with an engagement surface 96 (FIG. 8) formed on a portion of the rear flange member 68 adjacent to the center hole 74.
[0045]
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 of a complementary shape 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, and the tapered surface of the joint 75 and the engaging surface 96 are formed. Are engaged with each other in such a manner that their teeth are incapable of relative rotation. 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.
[0046]
At this time, the cylindrical boss portion 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 of the rolling bearings 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 part on the back side of the image carrier unit 41 is positioned.
[0047]
As described above, the image forming apparatus according to the present embodiment includes the drive shaft 72 for driving the image carrier 5, the rotatable support of the drive shaft 72, and the rear side plate on the rear side of the image forming apparatus main body 1. And a drive shaft holder 71 fixed to the drive shaft 60.
[0048]
On the other hand, the rear end of the central shaft 31 of the developing device 8 is rotatably fitted to a bearing 77 provided on the rear plate 60 of the image forming apparatus main body 1 without play, as shown in FIG. As a result, the rear side of the developing device 8 is positioned with respect to the image forming apparatus main body 1.
[0049]
As described above, the slide bearing 73 on the back side of the drawer 45 is fitted to the boss 71A of the drive shaft holder 71, and the center shaft 31 of the developing device 8 is fitted to the bearing 77 of the image forming apparatus main body 1. Thus, the back side of the drawer 45 is positioned with respect to the image forming apparatus main body 1.
[0050]
Further, when the drawer 45 is pushed into the inner side of the image forming apparatus main body 1, the positioning holes 78, 78A formed in the front side plate 46 of the drawer 45 as shown in FIGS. The positioning pins 79 and 79A projecting from the front plate 59 are fitted to each other, whereby the front side of the drawer 45 is positioned with respect to the image forming apparatus main body 1.
[0051]
When the drawer 45 is loaded at a predetermined position of the image forming apparatus main body 1 as described above, the back side and the front side of the drawer 45, that is, the entirety thereof, are positioned with respect to the image forming apparatus main body 1. A sliding bearing 73, a drive shaft holder 71 to which this is detachably fitted, a central shaft 31 of the developing device 8, a bearing 77 to which this is detachably fitted, positioning holes 78, 78A, and a positioning pin to which these are detachably fitted. Reference numerals 79 and 79A constitute an example of positioning means for positioning the drawer 45 with respect to the image forming apparatus main body 1 when the drawer 45 is pushed into a predetermined position of the image forming apparatus main body 1 and loaded. Further, 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.
[0052]
After the drawer 45 is 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 to the front end of the image carrier 5 as shown in FIG. That is, it is inserted into the center hole 80 formed at the center of the front flange member 67. 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 through the roller bearings 13 and 13A in the center hole of the driven shaft holder 82, but is fitted in the axial direction without being moved and without rattling.
[0053]
When the driven shaft 81 is inserted into the center hole 80 of the flange member 67 as described above, a hole 91 formed in the front plate 46 of the drawer 45 and a hole formed in the front plate 43 on the near side of the unit holder 40. The driven shaft holder 82 fits into 40A. In this way, the front end of the image carrier 5 and the front side of the image carrier unit 41 are positioned with respect to the drawer 45 already positioned with respect to the image forming apparatus main body 1. The image carrier 5, its drive shaft 72 and its driven shaft 81 are correctly positioned concentrically.
[0054]
As described above, the image forming apparatus according to the present embodiment includes the driven shaft 81 that 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, and the driven shaft 81. Are rotatably supported, and the drawer 45 is pushed into the back side and loaded in a predetermined position of the image forming apparatus main body 1, and is formed on the drawer 45 and the unit holder 40 of the image carrier unit 41, respectively. The unit holder 40 is fitted into the holes 91 and 40 </ b> A to position the front side of the unit holder 40 with respect to the drawer 45, and the front end of the image carrier 5 is connected to the drawer 45 via the driven shaft 81. And a driven shaft holder 82 for positioning.
[0055]
Further, the driven shaft 81 is provided with a compression coil spring 81A wound around the driven shaft 81 so as to rotate 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 is compressed, thereby pressing the image carrier 5 to the back. 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 the two is reliably inhibited.
[0056]
As described above, in the image forming apparatus of this example, when the drawer 45 is pushed in to the rear side and is loaded at a predetermined position of the image forming apparatus main body 1, the rear end of the image carrier 5 on the rear side, as shown in FIG. In the example, there is provided 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 illustrated example, the engaging means is fixed to the drive shaft 72 and has a tapered surface 75 whose diameter is reduced toward the near side of the image forming apparatus main body 1. It is wound around the driven shaft 81 so as to rotate together with the driven shaft 81 and the engagement surface 96 formed at the rear end and the tapered surface of the joint 75 is engaged with, and presses the image carrier 5 to the back side. , A spring for engaging the engagement surface 96 and the tapered surface of the joint 75 so that they cannot rotate relative to each other. It is and a grayed 81A. Thus, with a simple configuration, the rear end of the image carrier on the far side can be reliably positioned with respect to the drive shaft 72, and both can be reliably engaged.
[0057]
After the drawer 45 is positioned with respect to the image forming apparatus main body 1, the drawer 45 is fixed to the image forming apparatus main body 1, and the image carrier 5 is securely removed from the image forming apparatus main body 1 so as not to be detached therefrom. It is assembled to 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.
[0058]
As shown in FIGS. 8 to 10, a fixing member 97 made of a plate material generally called a face plate is firmly fixed to the driven shaft holder 82 by, for example, a screw (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 is fitted into each of the holes 91 and 40A. At this time, as shown in FIG. An elongated hole 99 formed in the fixing member 97 is fitted to a positioning pin 98 projecting from the front side plate 59 of the main body 1. Thereby, the fixing member 97 is correctly positioned with respect to the image forming apparatus main body 1. Thus, the fixing member 97 is firmly fixed to the front side plate 59 of the image forming apparatus main body 1 and the front side plate 46 of the drawer 45 by the screws 100, 100A, and 100B shown in FIG. In this manner, the components such as the image carrier 5 and the drawer 45 are correctly positioned and assembled with the image forming apparatus main body 1.
[0059]
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 fitted to the front end of the image carrier 5 (the front flange member 67 in the illustrated example). A fixing member 97 is fixed to the front side plate 59 of the image forming apparatus main body 1 in a state where the driven shaft holder 82 is fitted in each of the holes 91 and 40A of the drawer body 45 and 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.
[0060]
When the image forming operation is started in the above-described state, the pulley 83 fixed to the drive shaft 72 as shown in FIG. 9 is driven by a belt (not shown) wound therearound and other transmission elements. The image carrier 5 is rotated by a driving device (not shown), and the rotation is transmitted to the image carrier 5 to rotate the image carrier 5. At this time, the driven shaft 81 also rotates together with the image carrier 5. The developing device 8 and its components are also driven by a driving device (not shown) as described above, and the image forming operation described above is executed. At this time, the flywheel 101 is fixed to the drive shaft 72 as shown in FIGS. 8 and 9, whereby the image carrier 5 rotates stably, and the toner image of each color formed on the surface thereof is formed. Each toner image can be transferred to the intermediate transfer member 11 without causing a positional shift.
[0061]
Here, when it becomes necessary to remove the image carrier unit 41 and the developing device, the operation of the image forming apparatus is stopped, the screws 100, 100A, and 100B shown in FIG. The shaft holder 82 and the driven shaft 81 are detached from the image forming apparatus main body 1 as shown in FIG. 8, and the drawer 45 is pulled out to the near side, that is, in the direction of arrow B in FIG. 9, and the drawer 45 is not shown. The stopper is stopped at the position shown in FIG. As a result, the image carrier unit 41 and a desired developing device can be lifted upward and removed from the drawer 45. Further, 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.
[0062]
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. With the holder 40, it can be easily taken out or set. Further, in the present embodiment, the developing device 8 and its respective developing devices are also detachably attached to the drawer 45, so that they can be easily removed 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 unreasonable posture.
[0063]
Further, the unit holder 40 and the drawer 45 are located around the image carrier 5, and the axes for supporting and positioning the image carrier 5 are the drive shaft 72 and the driven shaft 81. 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.
[0064]
If the driven shaft and the drive shaft are integrated to constitute a single shaft, when the shaft is assembled to the image forming apparatus main body, the overall length becomes longer, so that play is likely to occur, and the position of the image carrier is increased. It is not easy to increase accuracy. In addition, when the flywheel is fixed to this one shaft, the weight tends to cause the front side of the shaft to lift upward, so that when the drawer is pushed in to the back side, 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 such a shaft is one, the weight is further increased and the cost is increased. To rise.
[0065]
By dividing the shaft into the drive shaft 72 and the driven shaft 81 as in the illustrated example, the above-described problem can be avoided.
[0066]
As shown in FIGS. 8 and 9, the drive shaft 72 is rotatably supported by the drive shaft holder 71 via rolling bearings 95, 95 A made of, for example, ball bearings. The outer race of the bearings 95 and 95A is press-fitted into the drive shaft holder 71 and fixed, and the inner race of the rolling bearings 95 and 95A is press-fitted into the drive shaft 72 and fixed, so that the drive shaft 72 is rolled on the drive shaft holder 71. The drive shaft 72 and the drive shaft holder 71 can be reliably assembled without bearings through the bearings 95 and 95A, and the positional accuracy of the image carrier 5 can be further improved.
[0067]
Similarly, the joint 75 is pressed into the drive shaft 72 and fixed, and the outer races of the rolling bearings (for example, ball bearings) 13 and 13A provided between the driven shaft 81 and the driven shaft holder 82 are attached to the driven shaft holder 82. By press-fitting and fixing the inner race to the driven shaft 81 and fixing it, the positional accuracy of the image carrier can be reliably improved.
[0068]
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 holder 71. The image carrier unit 41 is fitted with a simple structure by fitting into the outer race of a rolling bearing 95A for rotatably supporting and positioning the rear plate 44 of the unit holder 40 with respect to the image forming apparatus main body 1. It can be positioned in the image forming apparatus main body 1.
[0069]
By the way, as described above with reference to FIG. 4, the image forming apparatus of the present embodiment includes the intermediate transfer body 11 to which the toner image formed on the image carrier is transferred, and the frame supporting the intermediate transfer body 11. Although the intermediate transfer unit 94 is provided, the intermediate transfer unit 94 can also be loaded by being pulled out toward the front side of the image forming apparatus main body 1 or pushed into the back side. At this time, as shown in FIG. 4, an appropriate number of positioning pins 102, 102A; 103, 103A are provided on the front plate 92 and the rear plate 93 constituting the frame, respectively. When the intermediate transfer unit 94 is pushed into the rear side of the image forming apparatus main body 1, the positioning pins 103, 103A on the rear side are respectively inserted into positioning holes (not shown) formed in the rear plate 60 of the image forming apparatus main body 1. By fitting, the back side of the intermediate transfer unit 94 is positioned with respect to the image forming apparatus main body 1.
[0070]
After inserting the intermediate transfer unit 94 into the image forming apparatus main body 1 as described above, the driven shaft holder 82 is fitted into the drawer 45 and the holes 91 and 40A of the unit holder 40, and the fixing member 97 is It is attached to the image forming apparatus main body 1 as described above. At this time, the fixing member 97 is formed on each of the positioning pins 102 and 102A projecting from the front side plate 92 of the intermediate transfer unit 94 as shown in FIG. The positioning holes 104 and 104A are fitted respectively. Thereby, 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 in the holes 91 and 40A of the drawer body 45 and the unit holder 40, and the intermediate transfer body 11 Is positioned with respect to the image forming apparatus main body 1.
[0071]
According to the above configuration, the fixing member 97 fixes the drawer 45 to the image forming apparatus main body 1 and functions as a positioning plate for positioning the intermediate transfer unit 94 with respect to the image forming apparatus main body 1, and has a simple configuration. In addition, the intermediate transfer unit 94 can be positioned by an easy 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 furthermore, the image carrier 5 and the image carrier The positioning of the unit 41 is performed, so that all operations can be performed extremely easily.
[0072]
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 and detached from the drawer 45 together with the image carrier 5. You. Therefore, when the image carrier unit 41 is detached or attached from the drawer 45, 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 manner, the maintenance work on the image carrier 5, the cleaning device 14, and the developing device 8 can be performed efficiently without contaminating the periphery of the image forming apparatus with the toner.
[0073]
Further, in the image forming apparatus of the present embodiment, as described below, the image carrier 5 and the cleaning device 14 are removably assembled to the unit holder 40, and the image carrier 5 5 and the cleaning device 14, the image carrier 5 and the cleaning blade 33 can be cleaned or replaced.
[0074]
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. Then, 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.
[0075]
Here, each of the side plates 43 and 44 of the unit holder 40 is divided into two portions, and one of the fixed portions 43A and 44A is formed integrally with the top plate 42, and the other movable portion 43B and 44B is pivotally attached to the fixed parts 43A, 44A via a pivot pin 84, and the movable parts 43B, 44B are normally fixed to the fixed parts 43A, 44A by two screws 85.
[0076]
Then, after placing the image carrier unit 41 on the desk as described above, the screw 85 is removed, and the movable parts 43B and 44B are rotated as shown in FIG. Thus, the image carrier 5 is exposed to the outside, and the image carrier 5 can be removed from the unit holder 40 by lifting the image carrier 5 upward.
[0077]
In addition, as shown in FIG. 14, by removing another screw 86, the cleaning device 14 can be removed from the unit holder 40. 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. Since the work can be performed by placing the work 40 on a desk or the like, the work can be performed carefully and the toner can be prevented from spilling out from the opening 35.
[0078]
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 can be pulled out through the hole 89. . FIGS. 13 and 14 show a state after the charging charger 6 is pulled out.
[0079]
The cleaning device 14 and the image carrier 5 are assembled to the unit holder 40 by the operation reverse to the above-described operation, and then the image carrier unit 41 is set on the drawer 45, and the drawer 45 is placed inside the image forming apparatus main body 1. , Each element can be positioned at a predetermined position as described above.
[0080]
As shown in FIG. 6, the drawer 45 is pulled out from the image forming apparatus main body 1 to the near side and stopped, and the image carrier unit 41 is removed from the drawer 45 while the developing device 8 is stored in the drawer 45. However, when the image carrier unit 41 and the developing device 8 are both housed in the drawer 45 and set, the developing roller of the developing device occupying the image carrier 5 and the developing position is 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 surface of the image carrier 5 Of the developing device, particularly the developing roller, and the surface of the image carrier may be damaged. In order to prevent such a problem, the image forming apparatus of the present embodiment is configured as follows.
[0081]
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. As shown in FIG. It has a horizontal portion 49A on which the portion 87 is placed, and a vertical portion 49B that rises substantially perpendicularly to the horizontal portion 49A. In the vertical portion 49B, a guide piece 88 formed by cutting and raising the stay itself is formed. The guide piece 88 is provided at an angle θ larger than 0 ° and smaller than 90 ° with respect to the vertical portion 49B, and projects obliquely downward toward the portion 87 of the unit holder 40.
[0082]
Here, when the image carrier unit 41 supported by the first and second stays 48 and 49 is lifted upward to remove the image carrier unit 41 from the drawer 45, the portion 87 of the unit holder 40 is guided. 7, the image carrier unit 41 moves around the portion 87 in FIG. ₁ It rotates in the direction shown by. 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. With the image carrier 5 separated from the developing device 8 in this manner, the image carrier unit 41 is ₂ Is moved away from the developing device 8 as shown by the arrow, and the portion 87 of the unit holder 40 is removed from the guide piece 88, and the image carrier unit 41 is moved to the arrow S. ₃ Can be lifted upward as shown by.
[0083]
As described above, when removing the image carrier unit 41 from the drawer 45, if the image carrier 5 is not moved in the direction in which the image carrier 5 moves away from the developing device 8, the image carrier unit 41 is removed from the drawer 45. Therefore, the image carrier 5 may strongly hit the developing roller of the developing device 8 due to the carelessness of the operator during the removal operation, and the surface of the image carrier may be damaged. Can be blocked.
[0084]
As described above, in the image forming apparatus of the present embodiment, when the image carrier unit 41 is removed from the drawer 45, the image carrier unit 41 moves in a direction away from the developing device 8 held by the drawer 45. As described above, the guide for guiding the image carrier unit 41 is provided on the drawer 45. In the illustrated example, the guide piece 88 provided on the horizontal portion 49A of the second stay 49 and the vertical portion 49B. Constitute the guide.
[0085]
Moreover, when the image carrier unit 41 is lifted in order to remove the image carrier unit 41 from the drawer 45, the image carrier unit 41 moves around the upper portion 87 near the developing device. The image carrier unit 41 is guided such that the lower part thereof rotates in a direction away from the developing device 8.
[0086]
Further, 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 the portion forms the protrusion 90. Make up. That is, the unit holder 40 has the projecting portion 90 projecting outward from the outer peripheral surface of the image carrier 5. In addition, the unit holder 40 has a front side plate 43 and a rear side plate 44 that support each end in the axial direction of the image carrier 5, and a peripheral portion extending along the outer peripheral surface of the image carrier of the side plates 43 and 44. Project outward from the outer peripheral surface of the image carrier 5, and a projecting portion 90 is constituted by the projecting peripheral portion.
[0087]
According to the above configuration, when the image carrier unit 41 is taken out of the drawer 45 while the developing device 8 is set on the drawer 45, or when the image carrier unit 41 is attached to the drawer 45, the image carrier unit Even if the position 41 is not parallel to the developing device 8, the projection 90 of the unit holder 40 may hit an element of the developing device 8, for example, a developing roller of the developing device 8. Does not hit the developing roller, thereby preventing the problem that the surface of the image carrier is scratched.
[0088]
After the image carrier unit 41 is removed from the drawer 45, the operator mistakenly places the top plate 42 upward and places the image carrier 5 downward on a placement surface such as a desk. Even if it does, the surface of the image carrier 5 does not come into contact with the mounting surface because the protrusion 90 only hits the mounting surface, and also in this case, the defect that the surface of the image carrier is scratched is prevented. it can.
[0089]
The above-described configuration of the guide and the protruding portion 90 can effectively suppress the occurrence of damage to the image carrier 5 even if only one of them is used. This makes it possible to more effectively prevent the surface of the image carrier from being damaged.
[0090]
The present invention is not limited to a color image forming apparatus, and can be widely applied to an image forming apparatus that forms a single-color visible image, an image forming apparatus such as a printer, a facsimile, or a multifunction peripheral. Widely applied to image forming devices that transfer images directly to the final transfer material without transferring the images to the intermediate transfer member, and image forming devices that use an exposure device that forms an original image directly on the surface of the image carrier You can do it.
[0091]
【The invention's effect】
According to the image forming apparatus of the first aspect, the image carrier is assembled to the unit holder to form an image carrier unit, and the image carrier unit is attached to the main body of the image forming apparatus so as to be drawn out. Since the image carrier unit is mounted on the drawer, the image carrier unit can be easily attached / 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.
[0092]
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.
[0093]
According to the image forming apparatus of the third aspect, the image carrier unit can be correctly positioned with respect to the image forming apparatus main body with a simple configuration.
[0094]
According to the image forming apparatus of the fourth aspect, with a simple configuration, the driven shaft holder and the drawer are fixed to the image forming apparatus main body, and the image carrier is correctly positioned and assembled with the image forming apparatus main body. be able to.
[0095]
According to the image forming apparatus of the fifth aspect, the fixing member serves as a positioning member of the intermediate transfer unit, and a dedicated member for positioning the intermediate transfer unit can be omitted. Simplification and cost reduction can be achieved.
[0096]
According to the image forming apparatus of the sixth aspect, with a simple configuration, the image carrier can be securely 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. 1;
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 is 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 showing 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 for clarifying a guide piece provided on a second stay.
[Explanation of symbols]
1 Image forming apparatus main body
5 Image carrier
11 Intermediate transfer member
40 Unit holder
40A hole
41 Image carrier unit
44 Rear plate
45 Withdrawal body
59 Front side plate
60 Rear plate
70A hole
71 Drive shaft holder
72 drive shaft
75 Joint
81 Follower shaft
81A Spring
82 Follower shaft holder
91 holes
94 Intermediate transfer unit
95 Rolling bearing
95A rolling bearing
96 engagement surface
97 Fixing member

Claims (6)

An image carrier unit formed by holding an image carrier having a toner image formed on a surface thereof in a unit holder; and a drawer that removably holds the image carrier unit and is removably mounted on the image forming apparatus main body. A drive shaft for driving the image carrier, a drive shaft holder rotatably supporting the drive shaft, and fixed to a rear-side plate on the back side of the image forming apparatus main body; and the drawer. When loaded at a predetermined position in 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 connected to the drive shaft. Engaging means for positioning the drawer relative to the image forming apparatus main body when the drawer is loaded at a predetermined position of the image forming apparatus main body; and positioning means for positioning the drawer relative to the image forming apparatus main body on the front side of the image carrier. A driven shaft fitted to the front end so as to be relatively non-rotatable; While the driven shaft is rotatably supported and the drawer is loaded at a predetermined position of the image forming apparatus main body, the drawer is fitted into holes formed in the unit holder of the drawer and the image carrier unit. And a driven shaft holder for positioning the front side of the unit holder with respect to the drawer and positioning the front end of the image carrier with respect to the drawer via the driven shaft. . 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 press-fitted into the drive shaft and fixed. The image forming apparatus according to claim 1, wherein: 3. The image according to claim 2, wherein a hole formed in a rear plate on the back side of the unit holder is fitted to an outer race of the rolling bearing, and the rear plate of the unit holder is positioned with respect to the image forming apparatus main body. 4. Forming equipment. The image forming apparatus main body is fixed to the driven shaft holder, 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. The image forming apparatus according to claim 1, further comprising a fixing member fixed to the front side plate. 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, wherein the fixed member has a structure in which the driven shaft holder has a drawer and a unit holder. 5. The image forming apparatus according to claim 4 , wherein the intermediate transfer body is positioned with respect to the image forming apparatus main body by engaging with the frame of the intermediate transfer body in a state fitted in each hole. 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, and a joint formed at a rear end of the image carrier; The surface is engaged with an engaging surface, and the driven shaft is wound around the driven shaft so as to rotate together with the driven shaft, and the image carrier is pressed to the back side, so that the engaging surface and the tapered surface of the joint cannot be relatively rotated. The image forming apparatus according to any one of claims 1 to 5, further comprising a spring engaged with the image forming apparatus.

Images