JPH06250454A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To surely remove and recover toner remaining and sticking on a photosensitive body with the renewed cleaning unit at the time of exchanging a cleaning unit. CONSTITUTION:A reversing lever 26 is fixed in the vicinity of one end part of a rotary shaft 13a and further, a transmission gear 23 having the transmission of the driving force of a driving motor 15 is arranged in the vicinity of the other end part. The transmission gear 23 transmits torque in the direction of C1 from the driving motor 15 to the rotary shaft 13a, but when the rotary shaft 13a is rotated in the direction of C2, a ratchet wheel 23a is idled. In the exchange of the cleaning unit not shown in the figure, a user rotates the reversing lever 26 in the direction of C2, to reversely rotate a photosensitive drum 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus applied to an image forming apparatus such as a copying machine, a facsimile machine and a printer.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing the outline of a conventional printer.

Reference numeral 1 is a paper feed cassette containing recording paper P, and 2 is a paper feed cassette.
Is a pair of registration rollers, 3 is a photoreceptor belt stretched by rollers 4, 5 is a charger, 6 is a laser device,
7 is a developing device, 8 is a transfer charger, 9 is a cleaning unit, 10 is a static eliminator, 11 is a fixing device, and 12 is a paper discharge tray.

At the time of image formation, the recording paper P separated and fed from the paper feed cassette 1 by the paper feed roller 1a is conveyed in the direction of the registration roller pair 2 and is timed by the registration roller pair 2 so that the photoconductor belt 3 is rotated. And transcription charger 8
It is transported to the transfer position between the and. The photosensitive belt 3 moves in the direction A, which is an image forming direction, the surface thereof is charged by the charging charger 5, and further scanned by the laser beam emitted from the laser device 6 to form an electrostatic latent image on the surface. To be done. The electrostatic latent image is developed into a toner image by the developing device 7, and the toner image is electrostatically transferred onto the recording paper P by the transfer charger 8. The recording paper P on which the transfer is completed is conveyed to the fixing device 11, where it is heated and pressed to fix the toner image, and the recording paper P is discharged to the paper discharge tray 12.

On the other hand, after the transfer is completed, the photosensitive belt 3 is
Further, the cleaning unit 9 moves in the direction A, and the cleaning unit 9 removes and collects the residual toner attached to the transferred area where the transfer is completed. Next, in the transferred area, the charge is neutralized by the static elimination light from the static eliminator 10, and a new image is formed again.

FIG. 10 is a side sectional view showing a cleaning unit and a photosensitive belt in a conventional printer.

The cleaning unit 9 is constructed so as to be attachable to and detachable from the mounting position shown in the drawing, and is moved out of the apparatus by moving it in the B direction.

Further, in the cleaning unit 9, at the mounting position, the vicinity of the tip of the cleaning blade 9a is elastically contacted with the outer peripheral surface of the photosensitive belt 3 so that the photosensitive belt 3 moves in the A direction and the residual toner is transferred from the transferred area. T is peeled off, and the peeled residual toner T is stored in the waste toner tank 9b. When the residual toner T in the waste toner tank 9b exceeds a certain amount, the user replaces the cleaning unit 9 with a new one.

[0009]

However, when the cleaning unit 9 is removed, a large amount of residual toner T adheres to the vicinity of the contact position of the cleaning blade 9a on the photosensitive belt 3. When the cleaning unit 9 is replaced in such a state, when a new cleaning unit 9 is mounted, the vicinity of the tip of the cleaning blade 9a comes into contact with the residual toner T, and the residual toner T is peeled off from the photosensitive belt 3. Also, the residual toner T on the photosensitive belt 3 may be removed by the cleaning blade 9
It may be moved to the downstream side of the contact position of a. The residual toner T attached to the downstream side of the contact position is
At the time of image formation, charge removal, charging, exposure and toner development on the photoconductor belt 3 are adversely affected to deteriorate image quality, and the residual toner T peeled off from the photoconductor belt 3 is
The constituent members of the apparatus and the recording paper are contaminated, which causes deterioration of the performance of the apparatus and scumming of the recording paper P.

It is an object of the present invention to provide an electrophotographic apparatus in which residual toner adhering to a photoconductor during replacement of a cleaning unit is reliably removed and collected by the replaced cleaning unit.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is a photoconductor which moves in an image forming direction and forms a toner image, and which transfers the toner image to a recording medium at a transfer position. The cleaning member is attached to the main body of the apparatus, and the cleaning member is brought into contact with the photosensitive member at the mounting position to move the photosensitive member in the image forming direction and remain from the area where the transfer of the toner image is completed. An electrophotographic apparatus including a cleaning unit that removes and collects toner includes a moving unit that moves a photosensitive member in a direction opposite to an image forming direction when the cleaning unit is removed.

Further, the moving means is provided with an operating lever which is operated by an external force to move the photosensitive member in the reverse direction when the cleaning unit is pulled out.

Further, the moving means is provided with an interlocking mechanism for moving the photosensitive member in the reverse direction in association with the removal operation of the cleaning unit.

Further, the moving means is provided with an interlocking mechanism for moving the photosensitive member in the reverse direction in association with the opening operation of the opening / closing portion opened when the cleaning unit is removed.

Further, the moving distance for moving the photoconductor by the interlocking mechanism is set shorter than the length from the transfer position on the photoconductor to the contact position of the cleaning member.

[0016]

According to the above means, when the cleaning unit is removed, the residual toner adhered in the vicinity of the contact position of the cleaning member on the photoconductor is moved by the moving means for moving the photoconductor in the direction opposite to the image forming direction. Moves in the upstream direction of the contact position.

Further, when the cleaning unit is pulled out, the actuating lever which is actuated by an external force to move the photoconductor in the reverse direction enables the user to move the photoconductor in the reverse direction when the cleaning unit is pulled out. Become.

Further, when the cleaning unit is removed by the interlocking mechanism that moves the photoconductor in the reverse direction in association with the removal operation of the cleaning unit, the photoconductor moves in the reverse direction.

Further, when the opening / closing part is opened by the interlocking mechanism for moving the photoconductor in the opposite direction in conjunction with the opening operation of the opening / closing part, the photoconductor moves in the opposite direction.

Further, the moving distance of the photosensitive member is set to be shorter than the length from the transfer position on the photosensitive member to the contact position of the cleaning blade, so that the photosensitive member is exposed when the cleaning unit is pulled out or the opening / closing portion is opened. The residual toner attached near the contact position on the body moves to an intermediate position between the contact position and the transfer position.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. In addition, in FIG. 1 to FIG.
The members corresponding to the members described on the basis of FIG.

FIG. 2 is a block diagram showing the outline of a printer according to an embodiment of the present invention.

Reference numeral 13 is a photosensitive drum, 14 is an opening / closing portion pivotally supported by a support shaft 14a, and 20 is a CTM (cleaning toner magazine) in which a cleaning unit 9 and a toner supply tank 21 are integrally formed.

A toner image is formed on the photosensitive drum 13 in the same manner as the photosensitive belt 3 described with reference to FIG. 9 while rotating in the C1 direction. This toner image is transferred to the recording paper P at the transfer position. To be done.

The opening / closing part 14 is opened by rotating in the direction D2 from the position shown to expose the inside of the apparatus, and is closed by rotating in the direction D1 from the open position. By opening the opening / closing section 14, the user can easily remove the recording paper P jammed inside the apparatus, for example.

The toner supply tank 21 of the CTM 20 is filled with toner, and the CTM 20 is configured to be attachable to and detachable from the apparatus main body when the opening / closing section 14 is opened. At the mounting position, the toner replenishing tank 21 supplies the toner to the developing device 7 so that the toner in the developing device 7 is held at a predetermined amount or more. By replacing the CTM 20, the user can simultaneously collect the residual toner T and replenish the toner with respect to the apparatus main body.

FIG. 1 is a perspective view showing an example of a main part in this embodiment, and FIG. 3 is an explanatory view of a transmission gear in this embodiment.

The rotating shaft 13a of the photosensitive drum 13 is fixed with a reversing lever 26 protruding in the radial direction near one end, and the driving force from the drive motor 15 is transmitted near the other end. The transmission gear 23 is arranged.

The transmission gear 23 meshes with the intermediate gear 24, and the intermediate gear 24 meshes with the drive gear 25. When the drive motor 15 rotates the drive gear 25 in the E1 direction,
The driving force of the drive motor 15 is transmitted to the motor 23 via the intermediate gear 24. Here, the transmission gear 23 is driven by a driving mechanism such as a known claw brake (not shown).
If torque from 15 is transmitted, ratchet wheel
23a and the gear part 23b are fixed to rotate the torque in the C1 direction
Although transmitted to the gear 13a, the ratchet wheel 23a idles and does not transmit the torque to the gear portion 23b when torque in the direction C2 is applied from the rotary shaft 13a.

The reversing lever 26 is exposed at a position where it can be operated by the user with the opening / closing section 14 opened, and the reversing lever 26 is rotated in the C2 direction, whereby the photosensitive drum is rotated.
13 also rotates in the C2 direction. At this time, since the ratchet wheel 23a idles as described above, the torque in the C2 direction is not transmitted to the gear portion 23b.

When the CTM 20 is replaced, the user opens the opening / closing portion 14 to remove the CTM 20, and then rotates the reverse rotation lever 26 to rotate the photosensitive drum 13 in the C2 direction. At this time, for the rotation amount of the reverse rotation lever 26, for example, a display unit (not shown) for displaying a predetermined angle is provided near the reverse rotation lever 26, and the angle at which the reverse rotation lever 26 is rotated by the user is specified to be a predetermined angle or less. The predetermined angle is set equal to the angle θ from the contact position of the cleaning blade 9a shown in FIG. 4 on the photosensitive drum 13 to the facing position of the transfer charger 8.

After reversing the photosensitive drum 13, the user mounts a new CTM 20 in the main body of the apparatus. A large amount of the residual toner T adhered to the vicinity of the abutting position of the cleaning blade 9a at the time of removal is abutted as shown by a chain double-dashed line in FIG. 4 by reversing the photosensitive drum 13 by the angle θ or less. Move to a position away from the position. This allows the cleaning blade 9a when the CTM20 is mounted.
Of the cleaning blade 9 is contacted with the residual toner T to peel off the residual toner T from the photosensitive drum 13.
It is possible to prevent the residual toner T from adhering to the downstream side of the contact position of a.

By moving the residual toner T on the photosensitive drum 13 to the upstream side of the cleaning blade 9a, the residual toner T is surely removed and collected from the photosensitive drum 13 by the cleaning unit 9 during image formation. It is possible to prevent the residual toner T from adversely affecting the electrophotographic process such as charging, exposure, toner development and transfer. Further, by defining the reverse rotation amount of the photosensitive drum 13 at the time of replacement of the CTM 20 to be equal to or less than the angle θ, when a large amount of the residual toner T is dropped, the residual toner T is attached to the transfer charger 8 and transferred. Charger 8
It is possible to prevent a decrease in the ability of the.

FIGS. 5 and 6 are explanatory views showing an example of the interlocking mechanism in this embodiment.

Reference numeral 31 is a reversing gear arranged near one end of the rotating shaft 13a, and 32 is a reversing lever supported by a support shaft 32a fixed to the main body of the apparatus and having a tooth portion 32b formed at its tip. 33 is a spring for urging the reverse rotation lever 32 in the F2 direction, and 34 is a contact pin protruding from the side surface of the CTM 20.

Further, in the vicinity of the other end of the rotating shaft 13a, as shown in FIG.
The transmission gear 23 described with reference to FIG. 3 is arranged, and the reversing gear 31 is provided with a brake mechanism (not shown) similarly to the transmission gear 23, and a torque in the C2 direction from the outside is applied to the rotating shaft 13a. However, when a torque in the C1 direction is applied from the outside, the rotation shaft 13a idles and the C1 direction is transmitted.
It is configured not to transmit directional torque.

When removing the CTM 20 from the main body of the apparatus, the user removes the CTM 20 in the G2 direction shown in FIG. CTM20
As the contact pin 34 moves in the G2 direction as well, the reversing lever 32 rotates in the F2 direction by the urging force of the spring 33, and is indicated by a two-dot chain line in FIG. 6 while the CTM 20 is being withdrawn. Thus, the tooth portion 32b meshes with the reverse rotation gear 31, and the reverse rotation gear 31 is rotated in the C2 direction.

The reverse lever 32 is held in the position shown by the solid line in FIG.
Interlocked with the inserting operation of the TM20 in the G1 direction, the TM20 is pressed by the contact pin 34 to rotate in the F1 direction. When the tooth portion 32b of the reverse rotation lever 32 that rotates in the F1 direction meshes with the reverse rotation gear 31, the reverse rotation gear 31 idles with respect to the rotating shaft 13a as described above, and does not transmit torque in the C1 direction. By this,
The photosensitive drum 13 is held in a stopped state when the CTM 20 is mounted.

Further, the number of teeth of the tooth portion 32b of the reversing lever 32 is
The reverse rotation amount of the photosensitive drum 13 is set to be equal to or less than the angle θ described with reference to FIG.

According to the printer described with reference to FIGS. 5 and 6, the photosensitive drum 13 automatically reverses by a predetermined amount in association with the removal operation of the CTM 20, so that the user performs a special operation. The residual toner T adhering to the photoconductor drum 13 can be reliably removed and collected by the mounted CTM 20 without doing so.

7 and 8 are explanatory views showing another example of the interlocking mechanism in this embodiment.

Reference numeral 41 is a reverse rotation lever fixed to the opening / closing portion 14 and having a tooth portion 41a formed at the tip thereof, and reference numeral 42 is an intermediate gear meshing with the reverse rotation gear 31.

As described above, when the CTM 20 is replaced, the user opens the opening / closing portion 14 to remove the CTM 20, and then mounts a new CTM 20. The opening and closing part in the closed position shown in FIG.
By opening 14, the reverse lever 41 moves the support shaft 14a.
Is rotated in the D2 direction, the tooth portion 41a meshes with the intermediate gear 42 during the opening, and the intermediate gear 42 is rotated in the H2 direction. When the intermediate gear 42 rotates in the H2 direction, the reverse rotation gear 31 rotates in the C2 direction and the photosensitive drum 13 also rotates in the C2 direction. Here, the number of teeth of the tooth portion 41a and the reversing gear 3
The gear ratio of the intermediate gear 42 to 1 is set so that the reverse rotation amount of the photosensitive drum 13 is equal to or less than the angle θ described with reference to FIG.

By interlocking with the opening operation of the opening / closing section 14 and reversing the photoconductor drum 13 by a predetermined amount, the residual toner T from the photoconductor drum 13 is replaced when the CTM 20 is replaced without any special operation by the user. Can be prevented from peeling off, and the attached CTM 20 can surely remove and collect the residual toner T adhering to the photosensitive drum 13.

Further, the opening / closing part 14 in the open position shown in FIG.
Is closed, the reverse rotation lever 41 rotates in the D1 direction to rotate the intermediate gear 42 in the H1 direction. At this time, the intermediate gear 42 applies a torque in the C1 direction to the reverse rotation gear 31,
When the torque in the C1 direction is applied, the reverse rotation gear 31 does not transmit the torque in the C1 direction to the rotating shaft 13a. As a result, the photosensitive drum 13 is held in a stopped state when the opening / closing portion 14 is closed.

[0046]

As described above, according to the present invention,
By moving the residual toner adhering to the vicinity of the contact position of the cleaning member on the photoconductor to the upstream direction of the contact position, it is possible to prevent the residual toner from being separated from the photoconductor by the cleaning member when the cleaning unit is mounted. In addition, since it is possible to prevent the residual toner from adhering to the downstream side of the cleaning member when a new cleaning unit is installed, it is possible to prevent the residual toner that has peeled off from contaminating the inside of the device, and to prevent the residual toner that adheres to the photoconductor. It is possible to prevent the toner from adversely affecting the image formation.

Further, when the cleaning unit is removed, the user moves the photoconductor in the opposite direction,
When a new cleaning unit is attached, the residual toner adhering to the vicinity of the contact position on the photoconductor can be moved upstream of the contact position.

Further, when the cleaning unit is removed by the interlocking mechanism that moves the photoconductor in the reverse direction in association with the removal operation of the cleaning unit, the photoconductor moves in the reverse direction, so that the user performs a special operation. It is possible to move the photoconductor in the opposite direction when replacing the cleaning unit without performing the above.

Further, when the opening / closing part is opened, the photoconductor moves in the opposite direction by the interlocking mechanism for moving the photoconductor in the opposite direction in conjunction with the opening / closing operation of the opening / closing part, so that the user can perform a special operation. Instead, the photoconductor can be moved in the opposite direction when the cleaning unit is replaced.

Further, when the residual toner adhering to the vicinity of the contact position on the photoconductor moves to an intermediate position between the contact position and the transfer position, and the residual toner is peeled off when the photoconductor moves, for example, It is possible to prevent the residual toner from adhering to the transfer charger arranged to face the photoconductor, and prevent the photoconductor from moving in the opposite direction more than necessary.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a main part of an embodiment of a printer of the present invention.

FIG. 2 is a configuration diagram showing an outline of the present embodiment.

FIG. 3 is an explanatory diagram of a transmission gear in this embodiment.

FIG. 4 is an explanatory diagram of operations of a photosensitive drum and a CTM in this embodiment.

FIG. 5 is an explanatory diagram showing an example of an interlocking mechanism in the present embodiment.

FIG. 6 is an explanatory diagram showing an example of an interlocking mechanism in the present embodiment.

FIG. 7 is an explanatory diagram showing another example of the interlocking mechanism in the present embodiment.

FIG. 8 is an explanatory diagram showing another example of the interlocking mechanism in the present embodiment.

FIG. 9 is a configuration diagram showing an outline of a conventional printer.

FIG. 10 is a side sectional view showing a cleaning unit and a photoconductor belt in a conventional printer.

[Explanation of symbols]

9 ... Cleaning unit, 9a ... Cleaning blade, 13 ... Photosensitive drum, 13a ... Rotating shaft, 14 ... Opening / closing part, 23 ... Transmission gear, 26, 32, 41 ... Reversing lever,
31 ... Reversing gear, 33 ... Spring, 34 ... Contact pin,
42 ... Intermediate gear.

Claims (5)

[Claims] 1. A photosensitive member that moves in an image forming direction and forms a toner image and transfers the toner image to a recording medium at a transfer position, and is configured to be attachable to and detachable from an apparatus main body.
Also, an electrophotographic apparatus including a cleaning unit that brings a cleaning member into contact with the photoconductor at the mounting position, moves the photoconductor in the image forming direction, and removes and collects residual toner from the area where the transfer of the toner image is completed. An electrophotographic apparatus, comprising: a moving unit that moves a photoconductor in a direction opposite to an image forming direction when the cleaning unit is removed. 2. The electrophotographic apparatus according to claim 1, wherein the moving unit includes an operating lever which is operated by an external force to move the photoconductor in the reverse direction when the cleaning unit is pulled out. apparatus. 3. The moving means comprises an interlocking mechanism for interlocking with the removal operation of the cleaning unit to move the photoconductor in the reverse direction.
The described electrophotographic apparatus. 4. The moving means includes an interlocking mechanism for moving the photoconductor in the reverse direction in conjunction with an opening operation of an opening / closing part that is opened when the cleaning unit is pulled out. Item 1. The electrophotographic apparatus according to Item 1. 5. The moving distance of the photoconductor by the interlocking mechanism is set shorter than the distance from the transfer position on the photoconductor to the contact position of the cleaning member. Electrophotographic device.