JP2011141380A - Photoreceptor drum device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoreceptor drum device which can secure runout accuracy of a photoreceptor drum without being affected by the frequency of attaching and detaching the photoreceptor drum to and from a driving shaft, and obtaining satisfactory image quality, and an image forming apparatus equipped with the photoreceptor drum device. <P>SOLUTION: The photoreceptor drum device includes the photoreceptor drum, the drive shaft 4 that is inserted as a rotation center shaft for the photoreceptor drum and drives the photoreceptor drum rotatably, a first end face member that fits with one end of the photoreceptor drum in the center line direction, and a second end face member 3 that fits with the other end of the photoreceptor drum in the center line direction. The drive shaft 4 includes an insertion guide shaft part 4d disposed on the tip side and a fitting shaft part 4e connected to the insertion guide shaft part 4d whose diameter is larger than that of the insertion guide shaft part 4d. The second end face member 3 has a guide path part 3d into which the drive shaft 4 is inserted and whose inner periphery slides with the insertion guide shaft part 4d of the drive shaft 4 and a fitting part 3e disposed at the insertion port of the guide path part 3d as an opening whose inner diameter is larger than that of the guide path part 3d that fits with the fitting shaft part 4e of the inserted drive shaft 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photosensitive drum device used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile machine, and an image forming apparatus including the photosensitive drum device.

  A photosensitive drum used in an electrophotographic image forming apparatus is a part that needs to be replaced periodically because its surface is worn or its electrical characteristics are deteriorated according to the number of printed pages.

  As an image forming apparatus on the premise of such replacement of the photosensitive drum, for example, in Patent Document 1, a hollow cylindrical photosensitive member having photoconductivity is positioned inside the photosensitive member, and the photosensitive member is sandwiched from both ends. In a printing unit of an electrophotographic printing apparatus having a photosensitive drum composed of a wheel and a cap for rotating, and a rotating shaft for holding and rotating the photosensitive drum, the wheel is arranged in the direction of the central axis of the rotating shaft. There has been proposed an invention in which an adjusting means including a screw screwed so as to be movable is provided so that an eccentric amount between the photosensitive member and the rotating shaft due to variation in assembly can be adjusted.

  However, in the configuration of Patent Document 1, when the rotating shaft is inserted, the wheel and the rotating shaft are rubbed against each other, so that both wear out, and the shake accuracy of the photosensitive member when the photosensitive member is driven to rotate deteriorates. There was a problem.

  The present invention has been made in view of the above-described problems in the prior art.Wearing when the photosensitive drum is attached to and removed from the drive shaft does not affect the shake accuracy of the photosensitive drum, and the image quality is excellent. It is an object of the present invention to provide an obtained photosensitive drum device and an image forming apparatus including the photosensitive drum device.

The present invention provided to solve the above problems is as follows.
[1] A hollow cylindrical photosensitive drum (photosensitive drum 1) having photoconductivity on the outer peripheral surface, and a drive shaft (drive) that is inserted as a rotation center axis of the photosensitive drum and rotationally drives the photosensitive drum. A shaft 4), a first end face member (first end face member 2) fitted to one end in the center line direction of the photosensitive drum, and a second end face fitted to the other end in the center line direction of the photosensitive drum. A member (second end surface member 3), and the drive shaft is connected to the insertion guide shaft portion (insertion guide shaft portion 4d) provided on the distal end side, and the insertion guide shaft portion. The second end surface member is a guide in which the drive shaft is inserted and the inner peripheral surface slides with the insertion guide shaft portion of the drive shaft. The guide portion is provided in the passage portion (guide passage portion 3d) and the insertion opening of the guide passage portion A photosensitive drum device having a fitting portion (fitting portion 3e) which is provided as an opening portion having an inner diameter larger than that of the passage portion and is fitted to the fitting shaft portion of the drive shaft. Photosensitive drum device 100, FIGS. 2, 11, and 12).
[2] The photosensitive drum device according to [1], wherein when the fitting shaft portion and the fitting portion are fitted, the insertion guide shaft portion and the guide passage portion are separated from each other.
[3] The photosensitive drum device according to [1] or [2], wherein the insertion guide shaft portion and the fitting shaft portion of the drive shaft are connected by an inclined surface (inclined surface 4f). FIG. 11).
[4] The fitting portion of the second end surface member has an inclined surface (inclined surface 3f) whose inner diameter gradually increases toward the insertion port on the insertion port side of the drive shaft. 1]-[3] The photosensitive drum device (FIG. 12).
[5] The photosensitive drum device according to any one of [1] to [4], wherein the first end face member and the second end face member are fitted.
[6] Any one of [1] to [5], wherein any two or all of the photosensitive drum, the first end surface member, and the second end surface member are integrated. The photosensitive drum device according to claim.
[7] A photoconductive drum device (photosensitive drum) having a photoconductive drum-shaped photoconductive drum (photosensitive drum 1) on the outer peripheral surface and configured to be detachable from the image forming apparatus main body. Body drum device 100), charging means (charging device 30) for charging the outer peripheral surface of the photosensitive drum, and latent image forming means (exposure device) for forming a latent image on the outer peripheral surface of the charged photosensitive drum. 31), developing means (developing device 32) for developing a latent image on the outer peripheral surface of the photosensitive drum to form a toner image, and transfer means for transferring the toner image on the outer peripheral surface of the photosensitive drum to a recording medium In the image forming apparatus (printer 200) having the (corona transfer device 41), the photosensitive drum device (photosensitive drum device 100) according to any one of [1] to [6] as the photosensitive drum device. ) An image forming apparatus (FIG. 1).

According to the photosensitive drum device of the present invention, when the photosensitive drum component (consisting of the photosensitive drum 1, the first end surface member 2, and the second end surface member 3) is attached to the drive shaft, the inner diameter is likely to change due to wear. The guide passage portion does not contact the drive shaft (insertion guide shaft portion), and the fitting portion having a constant inner diameter with little wear contacts the fitting shaft portion, so that the second end surface of the cylindrical photosensitive drum Since the center position is determined so that the center on the member side and the rotation center of the drive shaft coincide with each other, it is possible to maintain good deflection accuracy of the surface of the photosensitive drum during rotation of the photosensitive drum device.
Further, in the photosensitive drum device of the present invention, the present invention can be realized even if any one or all of the photosensitive drum, the first end surface member, and the second end surface member are integrated, and not only the photosensitive drum. Further, by adopting a configuration in which the photosensitive drum constituents are replaced, it is possible to secure a more accurate shake accuracy of the surface of the photosensitive drum.
According to the image forming apparatus of the present invention, by using the photosensitive drum device of the present invention, it is possible to prevent deterioration of the shake accuracy of the surface of the photosensitive drum over time and obtain a good image.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to the present invention. 1 is a cross-sectional view illustrating a configuration of a photosensitive drum device according to the present invention. FIG. 3 is a cross-sectional view showing a state where a handle is removed from the photosensitive drum device of FIG. 2. FIG. 3 is a cross-sectional view showing a state where a photosensitive drum component is pulled out from a drive shaft in the photosensitive drum device of FIG. 2. It is sectional drawing which shows the structure of a photoreceptor drum structure. FIG. 6 is a front view showing the configuration of the photosensitive drum configuration in FIG. 5. It is sectional drawing which shows the structure of the state which removed the hexagon socket head bolt from the photosensitive drum structure of FIG. FIG. 6 is a cross-sectional view illustrating a configuration in a state where an operation member is operated as a separation unit in the photosensitive drum configuration in FIG. 5. FIG. 6 is a cross-sectional view showing a configuration in a state in which the photosensitive drum is removed from the second end surface member in the photosensitive drum configuration in FIG. 5. It is sectional drawing which shows the structure of the state which removed the 1st end surface member with respect to the photoconductor drum. FIG. 2 is an external view illustrating a configuration of a main part of a drive shaft used in the photosensitive drum device according to the present invention. It is an external view which shows the principal part structure of the 2nd end surface member used for the photosensitive drum apparatus which concerns on this invention. It is a cross-sectional enlarged view showing a contact state (1) between the second end face member and the drive shaft in the photosensitive drum device according to the present invention. It is a cross-sectional enlarged view showing a contact state (2) between the second end face member and the drive shaft in the photosensitive drum device according to the present invention.

Hereinafter, an embodiment in which the present invention is applied to a printer (hereinafter referred to as a printer 200) as an image forming apparatus will be described.
FIG. 1 is a schematic configuration diagram of the printer 200.
As shown in FIG. 1, a printer 200 includes a photosensitive drum device 100, and a charger 30, an exposure device 31, a developing device 32, and a transfer unit along an outer peripheral surface that moves as the photosensitive drum device 100 rotates. A corona transfer device 41 is arranged.

  After the charger 30 uniformly charges the surface of the photosensitive drum device 100, the exposure device 31 irradiates the surface of the photosensitive drum device 100 with the laser light L in accordance with the image data. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum device 100 and is developed by the developing device 32, and a toner image is formed on the surface of the photosensitive drum device 100.

  A web supply device 60 is arranged on the upstream side in the conveyance direction of the continuous web P that is a recording medium with respect to the transfer portion 40 where the photosensitive drum device 100 and the corona transfer device 41 face each other. The web supply device 60 applies a conveying force toward the transfer unit 40 to the continuous web P at a predetermined timing, and the continuous web P is not bent between the continuous web P and the resist device 61. A continuous web stretching roller 62 that stretches, a transport roller 63 (ac) that transports the continuous web P from a storage unit that stores the continuous web P before printing, and the like are provided. In the example shown in FIG. 1, a roll paper without a fold is used as the continuous web P. When roll paper is used, an accommodating portion is disposed outside the casing of the main body of the printer 200, and the continuous web P is passed under the main body of the printer 200 as shown in FIG. 1, and the first transport roller 63a, the second transport roller 63b, The third conveyance roller 63c is passed in order, and the continuous web stretching roller 62 is set so that the leading end of the continuous web P is sandwiched between the registration roller pair of the registration device 61.

  When continuous paper with a crease is used as the continuous web P, the continuous web P is folded and accommodated in a Z-shape in the apparatus accommodating portion 70 indicated by a one-dot chain line in the figure, and the leading end of the continuous web P is registered on the registration roller of the registration device 61 Set so that it is pinched.

  At the timing when the toner image formed on the surface of the photosensitive drum device 100 faces a predetermined portion on the continuous web P at the transfer unit 40, the registration roller pair of the registration device 61 is driven and directed toward the transfer unit 40. Thus, a continuous web P is supplied. There are various uses for the continuous web P, such as direct mail, bills, manuals, and books. In addition, with the expansion of applications, there are many types of paper used for the continuous web P, and various types of continuous web can be used from thin paper to thick paper, and from fine paper to rough paper. In particular, the width in the width direction of the continuous web used as the continuous web P (the length in the front-rear direction in FIG. 1) is also various. When the continuous web used as the continuous web P is switched to a different type, the web supply Position adjustment is performed so as to match the width direction position of the continuous web P that uses the position in the width direction of each conveying member (such as 61 to 63 in the drawing) included in the apparatus 60.

  In the transfer unit 40, the toner image formed on the surface of the photosensitive drum device 100 is transferred onto the surface of the continuous web P by the corona transfer unit 41. Then, the continuous web P that has passed through the transfer unit 40 is then conveyed toward the fixing unit 80 by the web supply device 60.

  The toner image transferred onto the surface of the continuous web P when the continuous web P conveyed toward the fixing unit 80 passes through the pre-heater 81 is heated to near the transition temperature of the toner resin. Further, the continuous web P reaches the fixing unit 80 including a heating roller 82 and a backup roller 83 with a built-in heater. In the fixing unit 80, the toner image on the continuous web P is heated and pressed by the heating roller 82 and the backup roller 83 to be melted and fixed on the surface of the continuous web P, and the toner image is fixed on the continuous web P. The continuous web P to which is fixed is stored in the stack unit 90 after printing.

  When performing double-sided printing, the toner image is transferred and fixed to the front surface (first surface) P1 of the continuous web P by the first printing using the printer 200 described above. Then, after the printing, the continuous web P stored in the stack unit 90 is taken out, and the continuous web P of the storage unit is set so that the surface opposite to the printing of the first printing becomes the surface to which the toner is transferred. Then, the toner image is transferred and fixed on the back surface (second surface) P2 of the continuous web P by the second printing.

Next, the configuration of the photosensitive drum device according to the present invention will be described.
FIG. 2 is a schematic cross-sectional view of an example (hereinafter referred to as Example 1) of the photosensitive drum device 100 according to the present invention applicable to the printer 200 of the present embodiment. FIG. 2 is a cross-sectional explanatory view in a cross section parallel to the drive shaft 4 of the photosensitive drum device 100 according to the first embodiment arranged in the printer 200.

  As shown in FIG. 2, the photoconductor drum device 100 is inserted as a hollow cylindrical photoconductor drum 1 having photoconductivity on the outer peripheral surface and a rotation center axis of the photoconductor drum 1. A drive shaft 4 that rotates, a first end face member 2 fitted to one end in the center line direction of the photosensitive drum 1, and a second end face member 3 fitted to the other end in the center line direction of the photosensitive drum 1. It is equipped with. At this time, the photosensitive member structure including the photosensitive drum 1, the first end surface member 2, and the second end surface member 3 is supported by the drive shaft 4 at a predetermined position of the printer 200 main body. Further, the drive shaft 4 is supported by the printer 200 main body by bearing members at both ends in the center line direction, and the front end portion 4b of the drive shaft 4 is in a state where the front cover 210 (see FIG. 3) of the printer 200 is closed. Thus, it is supported by a bearing (not shown) provided on the front cover 210.

Here, the outline of the procedure for replacing the photosensitive drum 1 will be described with reference to FIGS.
First, FIG. 3 and FIG. 4 show a procedure for removing a photosensitive drum constituent (consisting of the photosensitive drum 1, the first end surface member 2, and the second end surface member 3; the same applies hereinafter) from the printer 200. . In FIG. 3, the second end surface member 3 and the handle 5 are configured to be detachable from the drive shaft 4.

First, as shown in FIG. 3, the front cover 210 is opened, and the handle 5 on which the female screw is formed is loosened and removed from the drive shaft 4 having the male screw portion 4a.
Next, as shown in FIG. 4, the extension shaft 20 is attached to the male screw portion 4a of the drive shaft 4, and the first end face member 2 is grasped and pulled in the direction of arrow F in FIG. The photosensitive drum component is pulled out with respect to the drive shaft 4. As a result, as shown in FIG. 5, the photosensitive drum structure including the photosensitive drum 1, the first end surface member 2, and the second end surface member 3 can be taken out from the printer 200 main body.

  FIG. 5 is a cross-sectional explanatory view in the same cross section as FIG. 3 in the state of only the photosensitive drum constituent, and FIG. 6 is a front view of the photosensitive drum constituent. After the photosensitive drum component is taken out from the printer 200, the hexagon socket head bolt 6 is removed from the state shown in FIGS. 5 and 6 as shown in FIG.

  Next, as shown in FIG. 8, the operating member 10 is centered on the operating shaft 11 in FIG. 8 by pulling up the operating lever portion 10 b of the operating member 10 provided on the first end surface member 2 to the outside in the center line direction. An operation of rotating in the direction of arrow G is performed. By operating the operation member 10 in this way, the fixing member 12 is urged in the direction of arrow H in FIG. 8 by the elastic force of the spring member 13 which is the urging member, and the fixing member 12 is in the inner periphery of the photosensitive drum 1. The surface is pressed to fix the first end surface member 2 to the photosensitive drum 1. At the same time, the operation of the operation member 10 described above causes the eccentric cam portion 10 a of the operation member 10 to rotate, thereby pressing the first end surface side flange portion 3 c of the second end surface member 3. A force for separating the first end face member 2 is applied. As a result, the photosensitive drum 1 fixed to the first end face member 2 is separated from the second end face member 3 integrally with the first end face member 2 as indicated by an arrow I in FIG. Then, by fixing the second end face member 3 and pulling the first end face member 2 in the left direction in FIG. 8, the photosensitive drum 1, the first end face member 2 and the first end face member 2, as shown by an arrow J in FIG. Is removed from the second end face member 3. The member for applying the biasing force so that the fixing member 12 presses against the inner peripheral surface of the photosensitive drum 1 is not limited to the spiral spring member 13, and the first end surface member 2 is used as the photosensitive drum. Other elastic members such as leaf springs can be used as long as they can be fixed to 1.

  Next, an operation of rotating the operation member 10 in the direction of arrow K in FIG. 10 (the direction opposite to the arrow G in FIG. 8) is performed and returned to the original state (the operation member 10 is brought into the state shown in FIG. 5). As a result, the fixing member 12 is separated from the inner peripheral surface of the photosensitive drum 1. Accordingly, the pressing of the fixing member 12 against the inner peripheral surface of the photosensitive drum 1 is released, and the fixing of the first end surface member 2 and the photosensitive drum 1 is released, so that the first end surface member 2 is removed from the photosensitive drum 1. It will be in a removable state. Then, a hand or a tool is inserted from the opening of the photosensitive drum 1 on the side where the second end surface member 3 is fitted, and the photosensitive drum 1 is fixed, and the first end surface member 2 is gripped from the photosensitive drum 1. By pulling in the separating direction, the photosensitive drum 1 and the first end surface member 2 can be separated as shown in FIG. 10, and only the used photosensitive drum 1 can be collected.

  Then, only the photosensitive drum 1 is replaced with a new one, and the photosensitive drum 1 is held between the first end face member 2 and the second end face member 3 in a procedure reverse to the procedure for collecting the photosensitive drum 1 described above. Then, the photosensitive drum component is formed, and the pre-attaching cover 210 is closed on the drive shaft 4 to complete the replacement operation of the photosensitive drum 1.

  That is, first, the outer periphery of the first end surface outer peripheral portion 2a of the first end surface member 2 and the second end surface outer peripheral portion of the second end surface member 3 of the photosensitive drum 1 with respect to the inner peripheral surfaces of both ends in the center line direction. It fits so that the outer peripheral surface of 3a may contact, respectively. Specifically, the outer peripheral surface of the first end surface outer peripheral portion 2a of the first end surface member 2 is fitted to one inner peripheral surface of the end portion in the center line direction of the photosensitive drum 1, and the operation lever portion 10b of the operation member 10 is the first one. By operating the operation member 10 so as to protrude with respect to the end surface formed by the one end surface member 2, the fixing member 12 comes into contact with the inner peripheral surface of the photoconductive drum 1, and the first end surface member 2 and the photoconductive drum 1. And unite. Then, the first end surface side tip portion 3b of the second end surface member 3 is inserted from the other opening at the center line direction end portion of the photosensitive drum 1, and the first end surface side flange portion 3c hits the eccentric cam portion 10a. The second end face member 3 is inserted into the photosensitive drum 1.

  When the first end surface side flange portion 3c abuts against the eccentric cam portion 10a (when the state shown in FIG. 8 is reached), the inner peripheral surface of the first end surface inner peripheral portion 2b of the first end surface member 2 and the first end surface side distal end portion 3b. The outer peripheral surface of the second end surface member 3 and the other outer peripheral surface of the second end surface member 3 are in contact with each other. Then, the operation member 10 is operated so that the operation lever portion 10b is positioned along the end surface formed by the first end surface member 2, and the abutment of the eccentric cam portion 10a with respect to the first end surface side flange portion 3c is released. The first end face member 2 and the second end face member 3 are pressed from both ends in the center line direction of the body drum 1. Thus, as shown in FIG. 7, the outer peripheral surface of the first end surface outer peripheral portion 2a and the outer peripheral surface of the second end surface outer peripheral portion 3a are in contact with the inner peripheral surfaces of both ends in the center line direction of the photosensitive drum 1, respectively. The first end face member 2 and the second end face member 3 are fitted to the photosensitive drum 1. At this time, the first end surface member 2 and the second end surface member 3 are fitted so that the inner peripheral surface of the first end surface inner peripheral portion 2b and the outer peripheral surface of the first end surface side distal end portion 3b are in contact with each other.

  Further, from the state shown in FIG. 7, the first end face inner peripheral portion 2 b of the first end face member 2 and the first end face side flange portion 3 c of the second end face member 3 are screwed by the hexagon socket head bolt 6. The position of the first end face member 2 with respect to the second end face member 3 is fixed. Moreover, the force of the direction where the distance in the centerline direction of the 1st end surface member 2 and the 2nd end surface member 3 becomes narrow by adding the hexagon socket head bolt 6 is added. As a result, the end surfaces of both ends in the center line direction of the photosensitive drum 1 abut against the first flange portion 2a1 of the first end surface outer peripheral portion 2a and the second flange portion 3a1 of the second end surface outer peripheral portion 3a, respectively. Is held by the first end face member 2 and the second end face member 3. In this way, the position of the photosensitive drum 1 with respect to the second end surface member 3 is fixed by holding the photosensitive drum 1 by the first end surface member 2 and the second end surface member 3, and as shown in FIG. The photosensitive drum structure is detachable from the main body.

  When the photosensitive drum component is attached to the main body of the printer 200, as shown in FIG. 4, the extension shaft 20 is attached to the drive shaft 4, and the extension shaft 20 is inserted into the central opening of the second end face member 3. The photosensitive drum component is slid along the extension shaft 20 and the drive shaft 4 in the direction opposite to the arrow F direction in FIG. At the end of this slide, the butting surface 3g (FIG. 11) of the second end face member 3 is a bumping surface 4g (FIG. 12) which is a step between the small diameter portion (insertion guide shaft portion) 4d of the drive shaft 4 and the large diameter portion 4h. ).

  Next, the handle 5 abuts against the first end surface side tip portion 3b of the second end surface member 3 by screwing the handle 5 formed with the female screw into the drive shaft 4 formed with the male screw portion 4a. Thus, the position of the second end surface member 3 in the center line direction with respect to the drive shaft 4 is fixed by the abutment of the abutment surface 3g with respect to the abutment surface 4g and the abutment of the handle 5 with respect to the first end surface side distal end portion 3b. The large-diameter portion 4h of the drive shaft 4 is provided with a positioning frame (not shown) having a positioning pin at the tip, and the photosensitive drum component is slid so that the abutting surface 3g abuts against the abutting surface 4g. Thus, an engagement hole (not shown) provided in the abutting surface 3g engages with the positioning pin. The position of the rotation direction of the second end surface member 3 with respect to the drive shaft 4 is fixed by the engagement between the engagement hole of the abutting surface 3g and the positioning pin. As described above, the position of the second end face member 3 in the center line direction with respect to the drive shaft 4 and the position in the rotation direction are fixed, so that the drive shaft of the photosensitive drum 1 whose position is fixed to the second end face member 3 is fixed. The position relative to 4 is fixed. Thereby, the photosensitive drum 1 can be rotated by rotationally driving the drive shaft 4.

  Further, in the photosensitive drum device 100, as shown in FIG. 2, the inner peripheral surface of the first end surface side tip portion 3b of the second end face member 3 is on the tip side of the small diameter portion (insertion guide shaft portion) 4d of the drive shaft 4. The first end surface member 2 of the cylindrical photosensitive drum 1 comes into contact with the inner peripheral surface of the first end surface inner peripheral portion 2b of the first end surface member 2 in contact with the outer peripheral surface of the first end surface side tip portion 3b. The center position is determined so that the center on the side coincides with the center of rotation of the drive shaft 4.

  By the way, when attaching and detaching the photosensitive drum component along the drive shaft 4 and the extension shaft 20 as described above, a guide which is an inner peripheral portion of the second end face member 3 in the photosensitive drum component. Since the passage portion 3d rubs against the drive shaft 4 and the extension shaft 20, the guide passage portion 3d of the second end face member 3 is worn and a gap with the drive shaft 4 is increased.

  Here, the second end face of the cylindrical photosensitive drum 1 is brought into contact with the insertion guide shaft portion 4d of the drive shaft 4 by the guide passage portion 3d of the second end face member 3 when the slide insertion of the photosensitive drum component is completed. If the center position is set so that the center on the member 3 side and the rotation center of the drive shaft 4 coincide with each other, the guide passage portion 3d is worn by the attachment and removal of the photosensitive drum components as described above. Therefore, the shake accuracy of the surface of the photosensitive drum 1 at the time of rotational driving of the photosensitive drum device 100 is deteriorated, and the distance fluctuation with peripheral devices such as the charger 30, the developing device 32, and the corona transfer device 41 is increased, and the image quality is improved. It causes problems that cause degradation. In addition, when the image quality is significantly deteriorated, the second end face member 3 needs to be replaced. However, problems such as an increase in cost due to replacement of parts and an increase in maintenance cost due to replacement work also occur.

Therefore, in the present invention, the drive shaft 4 and the second end face member 3 in the portion A of FIG. 2 are improved by adopting the configurations as shown in FIGS. 11 and 12. FIG. 11 is a main part external view of the drive shaft 4, and FIG. 12 is a main part sectional view of the second end face member 3.
First, as shown in FIG. 11, the drive shaft 4 has an insertion guide shaft portion between an insertion guide shaft portion 4d and a large diameter portion 4h, which are small-diameter cylindrical shafts (small diameter portions) provided on the distal end side. 4d, and a fitting shaft portion 4e which is a cylindrical shaft having a diameter larger than that of the insertion guide shaft portion 4d and smaller than that of the large diameter portion 4h.

  Further, the insertion guide shaft portion 4d and the fitting shaft portion 4e of the drive shaft 4 are connected by an inclined surface 4f.

  Further, as shown in FIG. 12, the second end face member 3 has a circular tunnel shape, and the guide shaft portion in which the drive shaft 4 is inserted and the inner peripheral surface slides with the insertion guide shaft portion 4 d of the drive shaft 4. 3d, and a fitting portion 3e that fits with the fitting shaft portion 4e of the drive shaft 4 provided as an opening having an inner diameter larger than that of the guide passage portion 3d at the insertion opening of the guide passage portion 3d. The fitting portion 3e is a circular tunnel having a very short length.

  Further, the fitting portion 3e in the second end surface member 3 has an inclined surface 3f whose inner diameter gradually increases toward the insertion port on the insertion port side of the drive shaft 4.

With these configurations, when the photosensitive drum component is attached to the drive shaft 4, the contact relationship between the second end surface member 3 and the drive shaft 4 is as follows.
First, the photosensitive drum component is inserted into the extension shaft 20 so that the distal end of the extension shaft 20 is inserted into the insertion port of the second end surface member 3 that is the opening of the photosensitive drum component, and the drive shaft 4 side is inserted. Move. The outer diameter of the shaft of the extension shaft 20 and the outer diameter of the insertion guide shaft portion 4d of the drive shaft 4 are the same.

  At this time, since the inner diameter of the fitting portion 3e of the second end face member 3 is larger than the outer diameter of the shaft of the extension shaft 20 and the insertion guide shaft portion 4d of the drive shaft 4, there is no contact. The inner diameter of the guide passage portion 3d of the second end face member 3 is slightly larger than the outer diameter of the shaft of the extension shaft 20 and the insertion guide shaft portion 4d of the drive shaft 4, and the second end face member 3 is in the horizontal direction (the direction of gravity). The inner peripheral surface of the guide passage portion 3d moves while sliding on the outer peripheral surface of the extension shaft 20 and the drive shaft 4 extending in the direction perpendicular to the drive shaft 4. Note that a half of the difference (gap D) between the inner diameter of the guide passage portion 3d of the second end face member 3 and the outer diameter of the shaft of the extension shaft 20 and the insertion guide shaft portion 4d of the drive shaft 4 is 0.050 mm to 0, for example. .100 mm. Similarly, when the photosensitive drum component is removed, the guide passage portion 3d moves while sliding on the extension shaft 20 and the drive shaft 4.

  Therefore, the guide passage portion 3d and the insertion guide shaft portion 4d are rubbed with each other when the photosensitive drum component is attached and removed. Therefore, when this attachment and removal operation is repeated, the inner circumference of the guide passage portion 3d is repeated. The surface tends to wear in accordance with their repeated motion and its inner diameter tends to be large.

  Next, when the photosensitive drum component is pushed further inward than the state shown in FIG. 13 (the root side of the drive shaft 4 and the direction B in FIG. 13), the second end face member 3 is fitted as shown in FIG. The joint portion 3e and the fitting shaft portion 4e of the drive shaft 4 are fitted. Specifically, when the photosensitive drum component is pushed in from the state of FIG. 13, the inclined surface 3f on the second end face member 3 side comes into contact with the inclined surface 4f on the drive shaft 4 side. Then, by further pushing, the inclined surface 3f moves smoothly on the inclined surface 4f while sliding with the inclined surface 4f, so that the inner peripheral surface of the fitting portion 3e contacts the outer peripheral surface of the fitting shaft portion 4e. become. At this time, since the inner diameter of the fitting portion 3e and the outer diameter of the fitting shaft portion 4e are substantially the same, for example, the half of the difference between the two (gap E) is 0 to 0.050 mm, The drive shaft 4 is fitted by the fitting portion 3e and the fitting shaft portion 4e. Further, when the fitting portion 3e and the fitting shaft portion 4e are fitted in this way, the inner diameter of the guide passage portion 3d is larger than the inner diameter of the fitting portion 3e, and the outer diameter of the insertion guide shaft portion 4d is the fitting shaft. Since it is smaller than the outer diameter of the portion 4e, the guide passage portion 3d and the insertion guide shaft portion 4d are separated from each other. In addition, the length which the fitting part 3e and the fitting shaft part 4e are contacting is about 2 mm.

  Here, in the second end face member 3, the length that the inner peripheral surface of the fitting portion 3 e slides with the outer peripheral surface of the fitting shaft portion 4 e is made as short as possible, and the wear on the inner peripheral surface is suppressed as much as possible. . That is, the present invention is separate from the guide passage portion 3d that slides with the drive shaft 4 (insertion guide shaft portion 4d) when the photosensitive drum component is attached to and removed from the second end surface member 3 from the drive shaft 4. By fitting the drive shaft 4 (fitting shaft portion 4e) and providing the fitting portion 3e with a small amount of wear, the guide passage portion 3d and the insertion guide shaft portion 4d rub against each other as described above. Even if the inner diameter of the passage portion 3d increases with time, the fitting between the second end face member 3 and the drive shaft 4 is performed by the fitting portion 3e and the fitting shaft portion 4e. It becomes the composition which is hard to be influenced by.

  As a result, when the photosensitive drum component is mounted on the drive shaft 4, the guide passage portion 3d whose inner diameter is likely to change due to wear does not come into contact with the drive shaft 4 (insertion guide shaft portion 4d), and the inner diameter has almost no wear. The center position is determined so that the center on the second end face member 3 side of the cylindrical photosensitive drum 1 and the center of rotation of the drive shaft 4 coincide with each other when the fixed fitting portion 3e contacts the fitting shaft portion 4e. Therefore, the shake accuracy of the surface of the photosensitive drum 1 when the photosensitive drum device 100 is rotationally driven can be kept good.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. Can be changed within the range that can be conceived, and any embodiment is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 1st end surface member 2a 1st end surface outer peripheral part 2a1 1st flange part 2b 1st end surface inner peripheral part 3 2nd end surface member 3a 2nd end surface outer peripheral part 3a1 2nd flange part 3b 1st end surface side front end part 3c First end face side flange portion 3d Guide passage portion 3e Fitting portion 3f Inclined surface 3g Abutting surface 4 Drive shaft 4a Male screw portion 4b Shaft tip portion 4d Insertion guide shaft portion 4e Fitting shaft portion 4f Inclined surface 4g Butting surface 4h Large diameter Part 5 Handle 6 Hexagon socket head bolt 10 Operation member 10a Eccentric cam part 10b Operation lever part 11 Operation shaft 12 Fixing member 13 Spring member 20 Extension shaft 30 Charger 31 Exposure device 32 Development device 40 Transfer unit 41 Corona transfer device 60 Web supply Device 61 Registration device 62 Continuous web stretching roller 63 Conveying roller 63a First conveying roller 63b Second transport roller 63c Third transport roller 70 Storage unit 80 Fixing unit 81 Preheater 82 Heating roller 83 Backup roller 90 Stack unit 100 Photosensitive drum device 200 Printer 210 Front cover L Laser light P Continuous web

JP 2005-037796 A

Claims (7)

A hollow cylindrical photosensitive drum having photoconductivity on the outer peripheral surface;
A drive shaft that is inserted as a rotation center axis of the photoconductive drum, and rotates the photoconductive drum;
A first end face member fitted to one end in the center line direction of the photosensitive drum;
A second end face member fitted to the other end in the center line direction of the photosensitive drum,
The drive shaft is composed of an insertion guide shaft portion provided on a distal end side, and a fitting shaft portion connected to the insertion guide shaft portion and having a diameter larger than that of the insertion guide shaft portion.
The second end surface member includes a guide passage portion in which the drive shaft is inserted and an inner peripheral surface slides with an insertion guide shaft portion of the drive shaft, and an inner diameter of the guide passage portion in an insertion port of the guide passage portion. A photosensitive drum device having a fitting portion that is fitted as the fitting shaft portion of the drive shaft that is provided and inserted as a large opening.   2. The photosensitive drum device according to claim 1, wherein when the fitting shaft portion and the fitting portion are fitted, the insertion guide shaft portion and the guide passage portion are separated from each other.   3. The photosensitive drum device according to claim 1, wherein the insertion guide shaft portion and the fitting shaft portion of the drive shaft are connected by an inclined surface.   The fitting portion of the second end surface member has an inclined surface whose inner diameter gradually increases toward the insertion port on the insertion port side of the drive shaft. The photosensitive drum device according to 1.   5. The photosensitive drum device according to claim 1, wherein the first end surface member and the second end surface member are fitted to each other. 6.   6. The photoconductor according to claim 1, wherein any two or all of the photoconductor drum, the first end surface member, and the second end surface member are integrated. Drum equipment. A photoconductive drum device comprising a photoconductive drum-shaped hollow cylindrical photoconductive drum on the outer peripheral surface and configured to be detachable from the image forming apparatus main body;
Charging means for charging the outer peripheral surface of the photosensitive drum;
Latent image forming means for forming a latent image on the outer peripheral surface of the charged photosensitive drum;
Developing means for developing a latent image on the outer peripheral surface of the photosensitive drum to form a toner image;
An image forming apparatus having transfer means for transferring a toner image on the outer peripheral surface of the photosensitive drum to a recording medium;
An image forming apparatus using the photosensitive drum device according to claim 1 as the photosensitive drum device.