JP2007292794A - Charging device, and cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging device hardly transmitting vibration to a photoreceptor drum even when using a flexible joint. <P>SOLUTION: The charging device comprises: a charging roller 21 rotated by being in contact with the surface of the photoreceptor drum 10 in order to charge the surface of the photoreceptor drum 10; a charging cleaner 22 rotated by being in contact with the surface of the charging roller 21 in order to clean the surface of the charging roller 21; the flexible joint 24 connecting the charging cleaner 22 to a drive system; and an elastic member 29 arranged so as to be in contact with at least a part of the circumference of the flexible joint 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a charging device and a cleaning device used in an image forming apparatus such as a printer, a FAX, and a copying machine.

  An image forming apparatus such as a printer, a FAX, or a copying machine includes a photosensitive drum, a charging device, an exposure device, a developing device, a cleaning device, a fixing unit for fixing a toner image on a sheet, and the like. For maintenance and the like, the photosensitive drum, the charging device, and the cleaning device are configured as a drum unit.

  In recent years, a configuration in which a charging roller for charging the surface of a photoconductive drum and a brush roller for cleaning the charging roller are often used as the charging device. The charging roller of the charging device is driven by the rotation of the photosensitive drum, and the brush roller is connected to an input gear provided in the drum unit and is driven to rotate.

  Since the charging device is preferably configured to be removable from the drum unit for maintenance, the brush roller is connected to the input gear by a flexible joint as shown in, for example, Patent Document 1 (for example, Patent Document 1). reference.).

By using this flexible joint, even when the input gear provided in the drum unit and the shaft of the brush roller are slightly deviated from each other, the charging device can be smoothly attached and rotated.
JP-A-8-186684

  In the above-described image forming apparatus, it is preferable that the photosensitive drum is smoothly rotated by reducing external vibration as much as possible. However, when the brush roller is rotated, if the rotation axis of the flexible joint is slightly shifted and rotated, vibration occurs, and therefore the photosensitive drum may also generate vibration.

  The vibration caused by the flexible joint is transmitted to the photosensitive drum through the brush roller and the charging roller. However, when the driving system of the photosensitive drum and the brush roller is common, the vibration is transmitted more significantly through the driving system. Is done.

  A similar problem occurs when a flexible joint is used to connect the rubbing roller for cleaning the surface of the photosensitive drum and the input gear provided in the drum unit.

  An object of the present invention is to provide a charging device and a cleaning device in which vibration is hardly transmitted to a photosensitive drum even when a flexible joint is used in consideration of the above-described conventional problems.

In order to achieve the above object, the first present invention provides:
A charging roller that rotates in contact with the surface of the photosensitive drum in order to charge the surface of the photosensitive drum;
A charging cleaner that rotates in contact with the surface of the charging roller to clean the surface of the charging roller;
A flexible joint for connecting the charging cleaner to the first drive system;
And an elastic member arranged to contact at least a part of the periphery of the flexible joint.

The second aspect of the present invention is
The first driving system is the charging device according to the first aspect of the present invention, which is common to a second driving system for rotationally driving the photosensitive drum.

The third aspect of the present invention
The elastic member is the charging device according to the first aspect of the present invention, which is a low-repulsion elastic member.

The fourth aspect of the present invention is
The charging device disposed in a drum unit including a photosensitive drum,
The charging device according to the first aspect of the present invention is configured to be removable from the drum unit via the flexible joint.

The fifth aspect of the present invention is
A drum cleaning roller that rotates in contact with the surface to clean the surface of the photoreceptor drum;
A flexible joint for connecting the drum cleaning roller to the first drive system;
A cleaning device comprising: an elastic member arranged to contact at least a part of the periphery of the flexible joint.

  In the cleaning device of the fifth aspect of the present invention, it is preferable that the first drive system is at least partially in common with the second drive system for rotationally driving the photosensitive drum. In the cleaning device of the fifth aspect of the present invention, the elastic member is more preferably a low repulsion elastic member.

  According to the present invention, it is possible to provide a charging device and a cleaning device that hardly transmit vibration to the photosensitive drum even when a flexible joint is used.

  Hereinafter, a charging device according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a front configuration diagram of a drum unit in which a charging device according to an embodiment of the present invention is arranged. A drum unit 1 shown in FIG. 1 is one of units constituting a portion for forming a toner image to be transferred onto a sheet in an image forming apparatus such as a copying machine.

  The drum unit 1 includes a photosensitive drum 10, a charging device 20 for uniformly charging the surface of the photosensitive drum 10, and a cleaning for cleaning the surface of the photosensitive drum 10 after the toner image is transferred to a sheet. The unit 30 and the drive source 72 (refer FIG. 2) are provided. The charging device 20 is configured to be removable from the drum unit 1.

  In FIG. 1, when the drum unit 1 is disposed in the image forming apparatus, a configuration disposed around the photosensitive drum 10 is indicated by a one-dot chain line. As shown in FIG. 1, the charging device 20, the exposure unit 40, the developing unit 50, the transfer roller 60, and the like are arranged with reference to the rotation direction (arrow A direction) of the photosensitive drum 10.

  The cleaning unit 30 discards the rubbing roller 32 pressed against the surface of the photosensitive drum 10 by the spring member 31, a rubber blade (not shown) for removing residual toner from the surface, and the collected toner. And a collection roller 33 for this purpose. The rubbing roller 32 is a roller that polishes the surface of the photosensitive drum 10 using the remaining toner as a lubricant.

  The charging device 20 uniformly charges the surface of the photosensitive drum 10, so that the charging roller 21 pressed against the surface, the brush roller 22 for cleaning the surface of the charging roller 21, and the charging rollers 21 and a casing 23 that covers the brush roller 22.

  The charging roller 21 rotates following the rotation of the photosensitive drum 10 and is applied with a bias voltage obtained by superimposing a DC voltage and an AC voltage by a voltage application unit (not shown), so that the surface of the photosensitive drum 10 is applied. Charge. On the other hand, the brush roller 22 is controlled to be driven at a speed higher than the rotation speed of the charging roller 21. The brush roller 22 of the present embodiment corresponds to an example of a charging cleaner of the present invention.

  FIG. 2 is an enlarged perspective view of an end portion of the charging device and the photosensitive drum 10 of the present embodiment. FIG. 3 is a diagram showing a state where the housing 23 is removed from FIG. An input gear 71 disposed at the end of the housing 23 shown in FIGS. 2 and 3 is a first transmission system for transmitting the driving force of the driving source 72 provided in the drum unit 1 to the brush roller 22. 73. The brush roller 22 is rotationally driven by the driving force of the driving source 72. The photosensitive drum 10 is driven to rotate by being transmitted with a driving force from the driving source 72 via the second transmission system 74. The first transmission system 73 branches from the second transmission system 74 and is common to a part of the second transmission system 74. The first transmission system 73 includes a drive shaft and a gear, and the second transmission system 74 includes a drive shaft and a traction mechanism.

  The drive source 72 and the first transmission system 73 (including the input gear 71) of the present embodiment correspond to an example of the first drive system of the present invention, and the drive source 72 and the first transmission system of the present embodiment. The second transmission system 74 corresponds to an example of the second drive system of the present invention.

  As shown in FIG. 3, the input gear 71 is connected to the brush roller 22 by the flexible joint 24 provided in the charging device 20. In addition, the charging roller 21 is pressed against the photosensitive drum 10 by a spring member 25 disposed between the inner surface of the housing 23 above the bearing roller and the bearing portion.

  FIG. 4 is an exploded configuration diagram of the flexible joint 24. The flexible joint 24 includes a gear side member 26 that is connected to the input gear 71, a roller side member 28 that is connected to the shaft 22 a of the brush roller 22, and a connection member 27 that connects the gear side member 26 and the roller side member 28. It is configured.

  The roller side member 28 includes a disk-shaped disk member 28a, a columnar columnar member 28b having a smaller diameter than the disk member 28a, and two columnar projections 28c. The disk member 28a and the columnar member 28b are coupled to each other in a plane with the center axes of the disk member 28a and the columnar member 28b aligned. Further, the protrusions 28c are arranged at two places on the disk member 28a on the upper and lower sides of the opposite surface 28d on which the cylindrical member 28b is provided.

  On the other hand, the gear-side member 26 includes a disk-shaped disk member 26a, a columnar columnar member 26b having a smaller diameter than the disk member 26a, two columnar projections 26c, and a fitting projection 26d. ing. The disk member 26a and the columnar member 26b are coupled to each other in a plane where the center axes of the disk member 26a and the columnar member 26b coincide with each other. Further, the protrusions 26c are arranged at two places on the left and right sides of the flat surface 26e opposite to the surface on which the cylindrical member 26b of the disk member 26a is provided. The fitting protrusion 26d is provided on the plane of the cylindrical member 26b opposite to the surface on which the disk member 26a is provided. The fitting protrusion 26d is formed to have a cross shape when viewed from the central axis direction of the gear side member 26.

  An insertion hole 71a is formed in a cross shape in the input gear 71, and the gear-side member 26 is connected to the input gear by inserting the fitting projection 26d into the insertion hole 71a, and the input gear 71 rotates. Can be rotated.

  The connecting member 27 has a disk shape, and through holes 27a are formed at four positions corresponding to the above-described upper, lower, left, and right cylindrical protrusions 26c and 28c. The through hole 27a has an oval shape that is formed long toward the center 27b of the connecting member 27, and the projections 26c and 28c inserted into the through hole 27a are configured to be movable in the direction of the center 27b. Note that the width of the through hole 27a is substantially the same as the diameter of each of the cylindrical protrusions 26c and 28c. By connecting the roller side member 28, the connecting member 27, and the gear side member 26 (see the arrow in FIG. 4), the flexible joint 24 shown in FIG. 3 is configured.

  2, 3, and 4, the flexible joint 24 is covered with the housing 23 except for the fitting protrusion 26 d. The charging device 20 can be detached from the drum unit 1 by pulling out the fitting protrusion 26d from the input gear 71 provided on the drum unit 1 side. Here, since the projections 26c and 28c are movable in the through hole 27a of the connecting member 27, the position of the gear side member 26 can be shifted around the center axis of the roller side member 28. It becomes possible.

  With such a configuration, when the charging device 20 is attached to the drum unit 1 after the maintenance is completed, even if the center axis position of the brush roller 22 and the center axis position of the input gear 71 are misaligned, the gear side Since there is play in the position of the member 26, it is possible to smoothly connect to the input gear 71.

  FIG. 5 is a side view of the charging device 20 viewed from the direction of the rotation axis, and corresponds to a state in which the input gear 71 is removed from FIG. As shown in FIGS. 3 and 5, the diameters of the disk member 26 a, the connecting member 27, and the disk member 28 a of the flexible joint 24 are formed to have substantially the same size. An elastic member 29 is attached to the inner surface 23a of the housing 23 in the vicinity of the outer periphery of these three members 26a, 27, and 28a. Two elastic members 29 are provided and arranged downward from the ceiling of the inner surface of the housing 23 so as to sandwich the outer periphery of the members 26a, 27, and 28a. The elastic member 29 is a low resilience elastic member made of urethane foam, and is in contact with a part of the outer periphery of the three members 26a, 27, 28a.

  By providing the elastic member 29 in this way, vibration of the flexible joint 24 can be reduced. Therefore, even when the flexible joint 24 is used to connect the brush roller 22 to the drive system, the vibration is transmitted through the charging roller 21, the first transmission system 73, and the second transmission system 74. Transmission to the drum 10 can be reduced.

  In this embodiment, the elastic member 29 is in contact with all the three members 26, 27, 28 of the flexible joint. However, since the connecting member 27 vibrates most during rotation, at least the connecting member 27 is brought into contact with the elastic member 29, the effect of reducing vibrations can be obtained.

  In the roller side member 28, the elastic member 29 is in contact with only the outer periphery of the disk member 28a, but may be in contact with the outer periphery of the columnar member 28b. Note that the gear side member 26 may also be in contact with the outer periphery of the cylindrical member 26b.

  In this embodiment, the case where the flexible joint 24 and the elastic member 29 are used in the charging device 20 has been described. However, the flexible joint 24 and the elastic member 29 may be used in a cleaning unit 30 as an example of the cleaning device of the present invention.

  In this case, the flexible member 24 may be used between the rubbing roller 32 shown in FIG. 1 and the input gear of the transmission system for transmitting the transmission force from the drive source 72, and the elastic member 24 may be disposed around the flexible joint 24. . This transmission system is also shared with a part of the second transmission system 74.

  Even when used in the cleaning unit 30 as described above, it is possible to reduce the vibration generated by the flexible joint 24 from being transmitted to the photosensitive drum 10 via the common drive source and transmission system and the rubbing roller 32. It becomes. As the elastic member, it is more preferable to use a low-rebound elastic member.

  In this case, an example of the first driving system of the present invention corresponds to the transmission system between the driving source 72 and the rubbing roller 32 and the driving source 72. An example of the drum cleaning roller of the present invention corresponds to the rubbing roller 32. As described above, the rubbing roller 32 may be removable from the input gear by a flexible joint.

  In the above-described embodiment, the first transmission system 73 and the second transmission system 74 are connected to the same drive source 72 and have a common part in the transmission system. There may be no part and it may be connected to a separate drive source. Note that the transmission system for driving the rubbing roller 32 and the second transmission system 74 also have no common part and may be connected to different driving sources.

  Moreover, as a structure of a flexible joint, it cannot be overemphasized that this invention can be applied not only to the structure used by this Embodiment.

  The present invention can be applied not only to the brush roller and the rubbing roller 32 described above but also to a roller in contact with the photosensitive drum.

  The charging device and the cleaning device of the present invention have an effect of hardly transmitting vibration to the photosensitive drum even when a flexible joint is used, and are useful as an image forming apparatus such as a printer, a FAX, and a copying machine. .

1 is a front configuration diagram of a drum unit according to an embodiment of the present invention. FIG. 2 is an enlarged view of an end portion of the charging device and the photosensitive drum in the embodiment according to the present invention. FIG. 2 is an enlarged view of an end portion of the charging device and the photosensitive drum in a state where the housing is removed in the embodiment according to the present invention. The exploded configuration figure of the flexible joint in the embodiment concerning the present invention The side view of the charging device in embodiment concerning this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photosensitive drum 21 Charging roller 22 Brush roller 23 Case 24 Flexible joint 25 Spring member 29 Elastic member 71 Input gear 72 Drive source 73 1st transmission system 74 2nd transmission system

Claims (5)

A charging roller that rotates in contact with the surface of the photosensitive drum in order to charge the surface of the photosensitive drum;
A charging cleaner that rotates in contact with the surface of the charging roller to clean the surface of the charging roller;
A flexible joint for connecting the charging cleaner to the first drive system;
A charging device comprising: an elastic member arranged to contact at least a part of the periphery of the flexible joint.   The charging device according to claim 1, wherein the first drive system is at least partially in common with a second drive system for rotationally driving the photosensitive drum.   The charging device according to claim 1, wherein the elastic member is a low repulsion elastic member. The charging device disposed in a drum unit including a photosensitive drum,
The charging device according to claim 1, wherein the charging device is configured to be detachable from the drum unit via the flexible joint. A drum cleaning roller that rotates in contact with the surface to clean the surface of the photoreceptor drum;
A flexible joint for connecting the drum cleaning roller to the first drive system;
A cleaning device, comprising: an elastic member arranged to contact at least a part of the periphery of the flexible joint.

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