JP2009229677A - Transfer device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer device achieving facilitation of attachment/detachment of a transfer roll and preventing the transfer roll from falling off (coming off) even when a body cover of an image forming apparatus is operated to be opened or closed strongly, and to provide the image forming apparatus. <P>SOLUTION: The transfer device includes: a transfer roll 50; a supporting member 52 supporting the transfer roll 50 to be movable and rotatable in a radial direction of the transfer roll; an energizing member 54 energizing the supporting member 52 to one side in the radial direction of the transfer roll 50; and a pressing member 56 pressing the transfer roll 50 to the other side of the radial direction of the transfer roll to be releasable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transfer device and an image forming apparatus having the same.

  In Patent Document 1, the contact transfer member and at least a part of the transfer material guide member are configured as one transfer unit, while a portion corresponding to the transfer unit of the apparatus main body faces the transfer material conveyance path and can be opened and closed. A positioning mechanism is disclosed in which a door cover is provided, the transfer unit is detachably held on the door cover, and the transfer unit can be positioned when the door cover is closed.

JP 2005-172856 A

  However, in Patent Document 1, since the transfer unit is detachably held on the openable / closable door cover, the transfer roll falls off during the open / close operation, or the guide member is damaged or soiled when the transfer unit is removed. There is a risk of jamming of the paper (transfer material).

  SUMMARY An advantage of some aspects of the invention is that it provides a transfer device and an image forming apparatus that facilitate mounting and dismounting of a transfer roll and preventing the transfer roll from dropping (detaching) even in the case of a strong opening / closing operation.

  In order to achieve the above object, the present invention is characterized by a transfer roll, a support member that supports the transfer roll in a diametrical direction of the transfer roll, and a support member that rotatably supports the transfer roll. The transfer apparatus includes an urging member that urges one side in the diameter direction of the transfer roll, and a pressing member that releasably presses the transfer roll against the other side in the diameter direction of the transfer roll.

  Preferably, the transfer roll has a conductive shaft portion and a transfer roll main body provided around the shaft portion, and the support member supports the shaft portion, and the support member and the attachment member. The biasing member is conductive.

  Preferably, the transfer roll includes a tracking roll that controls an inter-axis distance with an image holding body on which a toner image transferred by the transfer roll is held.

  Preferably, the pressing member has a protection portion that covers an end portion of the shaft portion of the transfer roll, and has a cleaning portion that cleans the end portion of the shaft portion of the transfer roll.

  According to a second aspect of the present invention, there is provided an image forming apparatus main body having an openable / closable part, an image holding body for holding a toner image, and a transfer device provided in the openable / closable part. The transfer device includes a transfer roll provided to face the image holding member, a support member that supports the transfer roll in a diametrical direction of the transfer roll, and rotatably supports the support. An image forming apparatus comprising: an urging member that urges a member toward the image holding member in the diameter direction of the transfer roll; and a pressing member that releasably presses the transfer roll toward the counter image holding member in the diameter direction of the transfer roll. is there.

  Preferably, it has an engaging means for engaging the pressing member with the opening / closing portion so that the pressing member presses the transfer roll when the opening / closing portion is closed.

  Preferably, there is a release means for releasing the engagement of the pressing member with the opening / closing portion when the opening / closing portion is opened.

  According to the present invention, the transfer roll can be easily attached and detached, and the transfer roll can be prevented from falling off even in the case of a strong opening / closing operation of the opening / closing portion.

Next, an embodiment of the present invention will be described.
FIG. 1 shows an outline of an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, an image forming unit 14 is mounted in the image forming apparatus main body 12, and a discharge unit 16 is provided on the upper portion of the image forming apparatus main body 12. For example, a two-stage sheet feeding unit 18 is disposed below the image forming apparatus main body 12.

  Each paper feed unit 18 has a paper feed cassette 20 in which paper is stored and paper feed rolls 22a and 22b. Sheets stacked on the paper feed cassette 20 are registered by the rotation of the paper feed rolls 22a and 22b. It is conveyed to the roll 24.

  Further, on the downstream side of the registration roll 24, an image carrier 28 and a transfer device 30 of a process cartridge (developing cartridge) 26, which will be described later, are provided opposite to each other, and a fixing device 32 is provided further downstream thereof. .

  Accordingly, the sheet fed from the sheet feeding cassette 20 of the sheet feeding unit 18 by the sheet feeding rolls 22a and 22b is temporarily stopped by the registration roll 24, and passes between the image carrier 28 and the transfer device 30 at a timing. Then, the developer image is transferred, and the transferred developer image is fixed by the fixing device 32 and discharged to the discharge unit 16 by the discharge roll 34.

The image forming means 14 is of an electrophotographic type, and is charged by an image carrier 28 made of a photosensitive member, a charging device 36 made of, for example, a charging roll for uniformly charging the image carrier 28, and the charging device 36. An optical writing device 38 that writes a latent image on the image carrier 28 with light, a developing device 40 that visualizes the latent image of the image carrier 28 formed by the optical writing device 38 with a developer, and development by the developing device 40 A transfer device 30 to transfer the agent image onto the paper, a cleaning device 42 for cleaning the developer remaining on the image carrier 28, and a developer image on the paper transferred by the transfer device 30 are fixed on the paper. For example, the fixing device 32 includes a pressure roll and a heating roll. The optical writing device 38 is composed of, for example, a scanning type laser exposure device and traverses a process cartridge 26 described later to form a latent image on the image carrier 28. The cleaning device 42 includes a cleaning blade 44 that contacts the image carrier 28 and a developer recovery unit 46 that stores the developer scraped off by the cleaning blade 44.
The optical writing device 38 may use an LED or a surface emitting laser as another embodiment.

  In the process cartridge 26, the image carrier 28, the charging device 36, the developing device 40, and the cleaning device 42 are integrated, and these can be replaced as a unit.

The periphery of the transfer device 30 is shown in FIG.
The transfer device 30 includes a transfer roll 50, a support member 52, an urging member 54, and a pressing member 56.

  The transfer roll 50 includes a conductive shaft portion 58, a transfer roll body 60 made of conductive rubber provided around the shaft portion 58, and tracking rolls 62 provided at both ends of the shaft portion 58. The tracking roll 62 controls the interaxial distance from the image holding body 28 on which the toner image is held by the transfer roll.

The support member 52 is made of a conductive material, has a U-shape, and supports the shaft portion 58.
The urging member 54 is, for example, a compression coil spring made of a conductive material, and is provided between the two support columns 55.
When the support member 52 is urged by the urging member 54 on the lower surface, the transfer roll 50 is movable and rotatable in the diameter direction, and the support member 52 and the transfer roll 50 are pushed out to the image carrier 28 side.

The pressing member 56 is shown in FIGS.
The pressing member 56 is, for example, a lever, and includes a fixing part 64, a handle part 66, a front leg part 68, and a rear leg part 70. The fixing part 64 has, for example, a flat shape, and presses the shaft part 58 against the other side in the diameter direction of the shaft part 58 in a releasable manner. The handle portion 66 has, for example, a rectangular shape, and has a plurality of parallel protrusions 72 extending in the axial direction on the surface. Further, the handle portion 66 is connected to the fixed portion 64 at an angle of approximately 135 ° to 150 ° so that it can be easily grasped by hand. The front leg portion 68 is connected to the fixing portion 64 substantially vertically. The front leg 68 has a front leg tip 69 at the tip, and the transfer roll can be released freely with the front leg tip 69 as a fulcrum. The rear leg portion 70 is connected substantially perpendicularly to the fixed portion 64 and is in parallel with the front leg portion 68. Further, the rear leg part 70 has a pressing member engaging part 74 that engages with the main body engaging part 73 of the opening / closing part 75 in a notch shape at the tip.

FIG. 5 shows an outline of an image forming apparatus 10 having an opening / closing part 75 according to an embodiment of the present invention.
The image forming apparatus 10 includes an image forming apparatus main body 12 and an opening / closing unit 75. The image forming apparatus main body 12 and the opening / closing part 75 are connected by a hinge 76 at the lower end of the image forming apparatus 10. The opening / closing part 75 can be opened and closed by approximately 90 ° from the state where it is mounted on the image forming apparatus main body 12 with the hinge 76 as a fulcrum. Further, the transfer device 30 is attached to the opening / closing unit 75. By opening the opening / closing unit 75, the transfer device 30 is released from the image forming apparatus main body 12, and the transfer roll 50 is supported by the support member 52 in the direction of gravity. Can be exchanged in anti-gravity direction. Accordingly, since the opening / closing part 75 is opened and the transfer roll is supported in the direction of gravity, the transfer roll 50 can be easily detached and attached, and even if the opening / closing part 75 is opened strongly, the transfer roll is prevented from falling off. Can do.

6 to 8 show the state of the transfer device 30 when the opening / closing part 75 is closed.
A guide 77 is provided in the vicinity of the opening / closing part 75 of the image forming apparatus main body 12. The guide 77 extends to the left and right substantially horizontally with the apparatus main body 12 and has a shape that decreases as the distance from the opening / closing portion 75 increases. The guide 77 has a groove 78, a sensing member 80 provided in the groove 78, and a biasing member 82 provided in the groove 78. The sensing member 80 has an arc shape on the opening / closing part side. The biasing member 82 is, for example, a compression coil spring, is fixed on the side opposite to the opening / closing portion of the groove 78, and biases the other side of the arc shape of the sensing member 80. The sensing member 80 is urged by the urging member 82 and can move between the point P and the point Q along the groove 78 of the guide 77.

  After the shaft portion 58 of the transfer roll 50 is placed on the support member 52, the transfer device 30 moves so that the pressing member 56 covers the support member 52 using the front leg tip 69 as a fulcrum by closing the opening / closing portion 75. The shaft portion 58 of the transfer roll 50 is pushed into the support member 52 by the fixing portion 64 of the pressing member 56, and the pressing member engaging portion 74 of the pressing member 56 is against the urging force of the urging member 54. Engage with the main body engaging portion 73. Then, the protrusion 72 of the handle 66 touches the arc tip of the sensing member 80 at point P, and the transfer device 30 is guided along the guide 77 to the side opposite to the opening / closing portion. When the point Q is reached, the handle 66 is separated from the sensing member 80, and the transfer roll 50 is mounted, fixed, and positioned on the apparatus main body 12, and faces the image carrier 28. The transfer roll 50 and the support member 52 are urged in the direction of the image carrier 28 by the urging member 54. However, since the pressing member 56 is attached, the transfer roll 50 and the support member 52 are in a predetermined position. Further, it does not jump out toward the image carrier 28 side. Accordingly, the transfer roll 50 can be prevented from falling off the support member 52.

  When the opening / closing part 75 is opened, the transfer roll 50 moves in a direction away from the image carrier 28. Then, the protrusion 72 of the handle 66 is guided by the guide 77 from the point Q and is separated from the sensing member 80 at the point P, and the engagement between the pressing member 56 and the opening / closing part 75 is released.

  That is, since the transfer device 30 is engaged with the opening / closing portion by closing the opening / closing portion 75, it is possible to prevent forgetting work, and the engagement of the pressing member 56 is released by opening the opening / closing portion 75. One step of the operation can be omitted.

Next, the pressing member 56 according to the second embodiment is shown in FIGS.
The pressing member 56 in the second embodiment is obtained by attaching a protective cover 82 to the fixing portion 64 of the pressing member 56 in the first embodiment described above.
The protective cover 82 is connected substantially vertically so as to extend the fixing portion 64 in the axial direction and cover the tracking roll 62. That is, the protective cover 82 covers the tracking rolls 62 provided at both ends of the transfer roll 50 with two surfaces. Furthermore, for example, a cloth or a sponge that is the cleaning unit 84 may be provided on the inner surface of the protective cover 82. In this way, when the transfer roll 50 is removed, the tracking roll 62 that is easily soiled by the floating toner in the apparatus is provided. However, the fixing portion 64 is covered with the protective cover 82 and the cleaning portion 84 is contacted. By doing so, the dirt can be reduced and the operator's hand is not soiled.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. 5A is a plan view and FIG. 5B is a cross-sectional view taken along line AA when the transfer device according to the embodiment of the present invention is mounted. It is a top view at the time of pressing member installation concerning an embodiment of the present invention. It is a perspective view of a pressing member concerning an embodiment of the present invention. It is sectional drawing which shows a mode that the opening-and-closing part which concerns on embodiment of this invention was opened. It is sectional drawing which shows the mode of the transfer apparatus when the opening / closing part which concerns on embodiment of this invention is closed. It is sectional drawing which shows a mode that the transfer roll which concerns on embodiment of this invention is mounted | worn. It is sectional drawing which shows a mode that a transfer apparatus is mounted | worn through the guide which concerns on embodiment of this invention. It is a top view at the time of the pressing member installation concerning the 2nd Embodiment of this invention. It is a perspective view of the pressing member concerning the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 28 Image holding body 30 Transfer apparatus 50 Transfer roll 52 Support member 54, 82 Energizing member 56 Pushing member 58 Shaft part 62 Tracking roll 64 Fixing part 66 Holding part 72 Projection 73 Main body engagement Part 74 pressing member engaging part 75 opening / closing part 77 guide 78 groove 80 sensing member 82 protective cover 84 cleaning part

Claims (8)

A transfer roll;
A support member that supports the transfer roll in a diametrical direction of the transfer roll and rotatably supports;
A biasing member that biases the support member toward one side in the diameter direction of the transfer roll;
A pressing member that releasably presses the transfer roll against the other side in the diameter direction of the transfer roll; and
A transfer device having   The transfer roll has a conductive shaft portion and a transfer roll body provided around the shaft portion, the support member supports the shaft portion, and the support member and the biasing member are The transfer device according to claim 1, which is conductive.   The transfer apparatus according to claim 1, wherein the transfer roll has a tracking roll that controls an inter-axis distance from an image holding body on which a toner image transferred by the transfer roll is held.   4. The transfer device according to claim 1, wherein the pressing member includes a protection portion that covers an end portion of the shaft portion of the transfer roll. 5.   The transfer device according to claim 1, wherein the pressing member includes a cleaning unit that cleans an end of the shaft portion of the transfer roll. An image forming apparatus main body having an openable / closable portion that can be freely opened and closed;
An image carrier for holding a toner image;
A transfer device provided in the opening and closing unit,
The transfer device includes:
A transfer roll provided to face the image carrier;
A support member that supports the transfer roll in a diametrical direction of the transfer roll and rotatably supports;
A biasing member that biases the support member toward the image carrier in the diameter direction of the transfer roll;
A pressing member that releasably presses the transfer roll against the opposite side of the transfer roll in the diameter direction;
An image forming apparatus.   The image forming apparatus according to claim 6, further comprising an engaging unit that engages the pressing member with the opening / closing portion so that the pressing member presses the transfer roll when the opening / closing portion is closed.   The image forming apparatus according to claim 6, further comprising: a releasing unit that disengages the pressing member from the opening / closing portion when the opening / closing portion is opened.

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