JPH0746257B2 - Electrophotographic device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, and in particular, at least an image carrier, a developing device, and a cleaner are integrated into a unit, and the unit can be attached to and detached from the apparatus main body. The present invention relates to an electrophotographic device.

2. Description of the Related Art Generally, in an electrophotographic apparatus such as a copying machine, a latent image forming device, a developing device, and a developing device are provided around an image carrier such as a photosensitive drum.
Actuating devices such as a transfer device and a cleaner are arranged close to each other, and these devices are operated at appropriate timings. By the way, in these apparatuses, it is required to appropriately pull out each apparatus from the main body of the electrophotographic apparatus in order to replenish developer, replace consumables, perform maintenance inspection, or clear paper jam. These drawing operations require a preliminary operation of first separating the apparatus from the image carrier, which complicates the configuration of the apparatus and requires labor.

In recent years, for example, as disclosed in Japanese Examined Patent Publication No. 58-54392, it has been proposed that the photosensitive drum, the developing device, and the cleaner are integrally configured as a detachable unit to reduce the time and labor for the maintenance work. . Such a unit is mainly used in a small electrophotographic apparatus, and in addition to reducing maintenance work by a service person, for example, another color developing can be easily performed by replacing with a unit containing a developer of another color. There are advantages.

Problems to be Solved by the Invention By the way, when the unit is exposed to the outside of the apparatus after the unit is pulled out, the exposed surface of the image bearing member may be damaged by another device, or the image may be damaged. There is a problem that the surface of the carrier continues to be exposed and its photosensitive function deteriorates over time. In view of this, there is known a configuration in which, when the unit is pulled out, the exposed surface of the image bearing member is covered with a cover for protection, and the problems such as the damage are eliminated. Conventionally, the attachment / detachment of such a cover has been performed manually and the like independently of the operation of other devices, and the attachment / detachment thereof has been inconvenient.

On the other hand, in the unit configuration of the axial slide,
For example, in an electrophotographic apparatus that uses a large transfer material such as A2 size, it is necessary to form a sufficient width in front of the apparatus to slide the large unit in the axial direction. To be done. Furthermore,
For example, when replenishing the developer, all of the large unit must be pulled out from the main body of the apparatus, which leaves a problem that the work is complicated.

The present invention solves the above problems, and an object of the present invention is to provide an electrophotographic apparatus capable of performing the attachment / detachment operation of the cover and protecting the surface of the image carrier with a simple configuration. .

Still another object of the present invention is to provide an electrophotographic apparatus in which a large unit for a large transfer material can be easily pulled out.

Means for Solving the Problems In order to achieve the above object, an electrophotographic apparatus according to the present invention includes a drum-shaped image carrier, a developing device for developing a latent image formed on the image carrier, and a developing device. A unit having a cleaner for cleaning the surface of the image carrier after transferring an image is made detachable with respect to the main body of the electrophotographic apparatus in a direction substantially perpendicular to the axial direction of the image carrier, and the image carrier surface of the unit. A cover that is movable to a first position that exposes the image carrier and a second position that covers the image carrier is provided in the unit, and the device main body is interlocked with the mounting and dismounting operation of the unit in the mounting / removing direction. Provided is means for operating the cover to move in parallel in the main body so as to cover or open the surface of the image carrier, and the image carrier portion of the unit after the image carrier is covered by the cover is It is characterized in that it is pulled out of the apparatus main body.

With such a configuration, according to the present invention, the unit is attached / detached in the direction substantially perpendicular to the axial direction of the image carrier, and in conjunction with this, the cover is automatically attached / detached to / from the image carrier surface. It is something to do.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of an electrophotographic apparatus according to the present invention, in which an integrally constructed process unit 4 including a photosensitive drum 1, a developing device 2 and a cleaner 3 is incorporated in an apparatus main body 5. The apparatus main body refers to a machine body having a fixed frame containing, for example, an optical device, a transfer device, or a fixing device.

The process unit 4 is formed in a housing shape having both side plates 6 (only one is shown) that are substantially parallel to each other, and is detachably configured independently of the apparatus main body. The photosensitive drum 1 is formed on a substantially cylindrical substrate such as aluminum or synthetic resin,
It has a structure in which Se-based, CdS-based, or organic photoconductors are vapor-deposited or applied in layers, and an insulating layer such as a synthetic resin is formed on the surface of the photoconductors in some cases. Around the drum 1, a latent image forming device including a charger 7, a uniform exposure lamp 8 and an exposure system 9, a developing device 2 for developing the latent image, a transfer device for transferring the developed image to a transfer material. 10, a cleaner 3 for cleaning the surface of the photosensitive drum after the transfer, and a static elimination lamp 11 are operatively arranged in sequence. In this example, the cleaner, the photosensitive drum and the developing device are linearly arranged. Further, although the charger 7 is mounted on the process unit 4, it may be mounted on the apparatus main body side.

The charger 7 is attached to the guide rail 42 on the inner surface of the upper cover 41 of the process unit 4 so as to be slidable in the longitudinal direction. The upper cover 41 is pivotable about a support shaft 43 and, in its closed state, functions to prevent light from being exposed to the inside of the process unit from above. The cover 41 has openings 44, 4 for passing light from the lamps 8, 11 and the optical system 9.
5, 46 are provided, and cover plates 47, 48, 80 for closing the unit 4 when the unit 4 is pulled out from the apparatus main body and for shielding the photosensitive drum from light are provided in these openings so as to be openable and closable. The cover plate 47 is provided so as to pivot in the counterclockwise direction as seen in the figure around the support shaft supporting the lower end thereof to close the opening 45, and the cover plate 48 supports the lower end thereof. It is provided so that the opening 46 can be closed by pivoting in the clockwise direction as seen in the figure around a supporting shaft (shared with the supporting shaft of the cover plate 47 in the illustrated example). In the state where the process unit is pulled out from the apparatus main body, each of the cover plates 47 and 48 has an opening 45 by the action of a spring means (not shown) such as a torsion coil spring or a tension spring connected to the cover plate. , 46 are in the closed position, and when the process unit is mounted in the main body of the apparatus and is in a predetermined position, it is pivoted in the direction of opening the openings 45, 46 against the action of the spring means. Move to the open position shown. The opening / closing operation of the cover plates 47, 48 can be performed by using an appropriate cam means. As an example, the mounting direction of the process unit into the apparatus main body (first direction) is provided at one end side of the cover plate 47 in the longitudinal direction (direction perpendicular to the drawing) so as to pivot integrally with the cover plate 47.
A cam with a cam surface that is slanted upward toward the left (as viewed in the figure) is fixed, and this slanted cam surface is fixed inside the machine body when the process unit is installed in the machine body. A cover plate that comes into contact with a contact member such as
Pivoting 47 clockwise against the action of the spring means and opening
Position 45 in the open position. On the contrary, when the process unit is pulled out from the apparatus main body, the cover plate 47 pivots counterclockwise by the restoring action of the spring means to close the opening 45 because the cam surface is separated from the contact member. The cover plate 48 covers a cam surface that is inclined in the opposite direction to the cam surface of the cover plate 47, that is, a cam surface that is inclined obliquely downward toward the mounting direction of the process unit in the apparatus body. By providing the plate 48 at one end side in the longitudinal direction, the opening / closing operation can be performed in the same manner as the cover plate 47. Further, the cover plate 80 has an opening 44 in the illustrated example.
It is provided so as to be slidable in a substantially horizontal direction by an appropriate guide means so that the process unit can be closed, and the cover plate when the process unit is pulled out from the apparatus main body.
It is positioned so as to close the opening 44 by the action of a spring means (not shown) such as a tension spring connected to 80, and when the process unit is mounted in the apparatus main body, the opening 44 is opened by the above-mentioned cam means. To slide.

The optical system 9 forms an optical path for guiding optical information from an original document (not shown) to the surface of the photosensitive drum, and in the illustrated example, a reflected light image from the original document placed on the original table is not shown in the figure. 49
And, it is introduced through the dustproof glass plate 50. Of course,
In addition to the above configuration, an optical path may be formed by using a short focus imaging element array, or a digital information device such as a laser beam device or a liquid crystal device may be used as an information source.

The developing device 2 includes a rotating magnetic roller 12 and a developer container 13, and one-component or two-component developer 14 in the container is provided to the surface of the photosensitive drum by the action of the magnetic roller 12. The developing device 2 itself is formed as a small unit, is arranged in a proper place in the process unit, and can be attached to and detached from the unit 4 when the unit 4 is pulled out from the apparatus main body 5 as described later. . Reference numeral 15 is an upper cover of the unit that covers the upper portion of the developing device 2 and can be opened and closed with the pin 16 as a fulcrum.

The transfer device 10 is arranged in the main body of the device, and the transfer corona discharger 1
7, separate corona discharger 18, and a slip-shaped guide member for guiding the transfer material between the discharger and the photosensitive drum
Including 19 The device 10 extends in the axial direction of the photosensitive drum, and is fixed to a frame body (supporting device) 20 which is provided on both sides of the photosensitive drum and can pivot about a fulcrum 21. The dischargers 17, 18 are removable in the longitudinal direction along the respective guide rails.
The upper surface of the transfer device is in a position close to the drum surface when the process unit 4 is mounted in the operating position of the apparatus main body, and is attached to or detached from the transfer device to release the attachment / detachment passage of the unit 4 when the unit 4 is attached / detached. It moves to the retracted position (broken line position in FIG. 1) interlockingly. In this example, the separating corona discharger 18 is incorporated into the transfer device as the peeling means, but it may be omitted and the peeling claw may be provided separately from the transfer device 10.

The fulcrum 21 also serves as a fulcrum of a guide belt drive roller for guiding the transfer material separated from the drum. A plurality of strip-shaped endless belts are stretched around the roller 21 and the rollers 22 and 23 separated from the roller 21, and the transfer material is conveyed together with the action of a suction box 25 arranged inside the belt. The rollers 22, 23 and the suction box 25 are supported by the frame body 20 and move along with the pivotal movement of the frame body 20.

The cleaner 3 includes an AC static eliminator 26, a cleaning blade 27,
It has a developer transport roller 28 and a recovery screw 29. The blade 27 is appropriately pressed against the surface of the photosensitive drum, and scrapes off the developing powder remaining on the drum neutralized by the static eliminator 26.
Drop onto roller 28. The roller 28 is made of a material such as sponge, rotates in the forward direction of the photosensitive drum and at a higher speed than that, and conveys the developing powder removed by the blade to the recovery screw. Reference numeral 31 is an elastic piece for scraping off the developing powder from the roller 28. Recovery screw
Numeral 29 appropriately rotates to convey the developer powder in a direction perpendicular to the paper surface as viewed in FIG. 1 and store it in a recovery bottle (not shown).

In order to supply the transfer material to the image transfer section, paper feed sections 32 and 33 are provided in the lower portion and the side portion of the apparatus main body in this example. Each of the sheet feeding units is a cassette type, and a cassette in which transfer materials of different desired sizes are stacked can be detachably loaded from the side or front of the apparatus. During operation, one of the transfer materials is selected and one of the paper feed rollers 34 and 35 corresponding thereto is rotated to supply the transfer material.

The transfer material supplied from the paper supply unit is supplied to the transfer unit by a pair of timing rollers 53 in synchronization with the rotation phase of the photosensitive drum. This supply is performed through a guide path defined by a pair of spaced apart guide plates 54. One of the timing roller 53 and one of the guide plates 54 is arranged in the apparatus main body 5, and the other timing roller and the guide plate are arranged in the process unit 4. With this configuration, when the transfer material is clogged near the timing roller, the timing roller and the transfer material guide portion are released by pulling the unit 4 out of the apparatus main body to easily remove the transfer material that causes the transfer material. Can be done.

Next, the attachment / detachment of the process unit 4 will be described. As described above, the photosensitive drum 1, the developing device 2 and the cleaner 3 are designed to be integrally movable, and constitute a process unit attachable / detachable to / from the apparatus main body 5. There is.

As shown in FIG. 2, the process unit 4 has a plate-like slider 36 fixed to the outer surfaces of both side plates 6 thereof, which extends in a substantially horizontal direction and in a direction substantially perpendicular to the axis of the photosensitive drum. The unit 4 is slidably engaged with the slide bearing device 37 (for example, Acculide: trade name) fixed to the device main body 5 and extending in the same direction, so that the unit 4 can be pulled out in the direction. Reference numeral 38 denotes ball bearings arranged at appropriate intervals in the longitudinal direction of the bearing device 37. In FIG. 1, reference numeral 51 is an end cover that can pivot about the pin 52 as a fulcrum.

As shown in FIG. 1, when mounting the process unit 4, the stopper receiving portions 55 and 56 provided at the front and rear ends of the side plate of the process unit 4 are brought into contact with the stoppers 57 and 58 of the apparatus main body along the slide bearing device 37. It is performed by sliding up to. In this position the unit 4 is fixed by the action of suitable clamping means.

In this mounted state, the lamps 8 and 11 are fixed at positions apart from the unit 4, but the transfer device 10 and the guide plate 54 are close to the surface of the photosensitive drum 1 and obstruct the attachment / detachment passage of the unit 4. In position. As described above, the transfer device 10 and the lower guide plate 54 are fixed to the frame body 20 that can pivot about the fulcrum 21, and the direction in which the frame moves toward and away from the photosensitive drum in accordance with the pivotal movement of the frame body. Move to. On the other hand, the frame body 20 is biased by the action of the tension spring 61 so as to rotate counterclockwise as viewed in FIG. 1, and a part of the frame body 20 abuts on the stopper 62 fixed to the apparatus main body. Further rotation is prevented, and the optimum position of the transfer device with respect to the photosensitive drum is determined.

In addition to the above configuration, in order to drive the frame body 20, a rotatable roller 63 is provided above the free end of the frame body 20 so that a part of the frame 63 is exposed above the upper end of the frame body. On the lower surface of both side plates 6 of No. 4, a cam surface 64 projecting downward so as to be engageable with this roller is formed. In the illustrated example, since the lower surface of the photosensitive drum forms the lowermost surface of the unit 4, the cam surface is
Although 64 forms an arc surface concentric with the photosensitive drum 1 and having a larger diameter than that, it is not limited to this shape and may be a linear inclined surface or the like. Further, in the case where the lowermost surface of the unit is a lower surface such as a cleaner, a cam surface projecting further below the lowermost surface is formed at an appropriate position on the cleaner side.

By setting the cam surface 64 and the roller 63 as described above, the cam surface 64 gradually pushes down the roller 63, and thus the frame body 20 and the transfer device 10 in accordance with the attachment / detachment operation of the unit 4, and releases the moving path of the unit 4. .

On the other hand, the process unit 4 taken out from the apparatus body 5
The upper surface of the photosensitive drum surface is blocked by the upper cover 41 and the cover plate, but the lower drum surface is exposed to external light. As is well known, such exposure has a problem that the photosensitive function of the photosensitive drum is deteriorated. At the same time, the problem that the exposed drum surface is damaged by another device or the like, or the problem that the developing powder is dropped and contaminated from the gap around the drum of the unit remains.

In order to solve these problems, a lower cover 70 that covers the lower surface of the drum when the unit is taken out is provided.

The operation of the cover 70 will be described with reference to FIGS. 3 to 5.

A rail 71 extending in the attachment / detachment direction of the unit 4 is provided on the outer surface of both side plates 6 of the unit 4, and a movable body 72 is slidably arranged along the rail 71. One end of a pair of parallel links 73, 74 is pivotally attached to the moving body 72, and the links 73, 74
The other end thereof is pivotally attached to the side surface of the cover 70. Mobile 72
Is urged to move to the left in FIG. 3 by the action of a tension spring 75 having one end fixed to it and the other end fixed to the side plate 6. On the other hand, the link 74 is urged to rotate clockwise by the action of a tension spring 76 having one end fixed to the link 74 and the other end fixed to the moving frame 72. The cover 70 has a size and shape sufficient to cover the lower surface of the photosensitive drum 1 and shield it from light, and its four corners are supported by links 73 and 74. The cover 70 is preferably made of an opaque or translucent synthetic resin or metal material.
A rotatable roller 77 is rotatably supported on the outer surface of the side wall of the cover 70.
On the other hand, an upright stopper 78 is fixed at a position facing the attachment / detachment passage of the unit of the apparatus main body 5 so as to be engageable with the roller 77.

FIG. 3 shows a state in which the unit 4 is loaded in the operating position of the apparatus main body. In this state, the roller 77 contacts the stopper 78, the cover 70 is at the retracted position apart from the photosensitive drum, and the photosensitive drum surface is exposed. is doing. As the unit 4 is pulled out, the moving body 72 relatively moves to the left along the rail 71 by the action of the spring 75 (FIG. 4). By further pulling out the unit, the links 74 and 75 rotate clockwise by the action of the spring 76, and the roller 77 stops accordingly.
It moves upward while contacting 78, and finally the cover 70 contacts the lower surface of the side plate 6 to cover the lower surface of the photosensitive drum, and shields and protects it. The cover 70 is held in this position by the action of the springs 75 and 76, and keeps the same position when the unit is further pulled out or taken out from the apparatus main body.

When the unit 4 is attached, contrary to the above operation, first
77 contacts the stopper 78, moves in the order shown in FIGS. 5, 4, and 3, and is loaded into the apparatus main body with the drum surface exposed.

As described above, according to the present invention, since the process unit is configured to be attached / detached in the direction substantially perpendicular to the axial direction of the photosensitive drum, the space required for pulling out the unit can be minimized. Since the developing device side is pulled out to the front, the unit can be conveniently handled when replenishing the developer by pulling out the unit so that only the replenishing port of the developing device is exposed from the main body of the device.

In addition, the transfer device can be separated from the surface of the photosensitive drum in conjunction with the unit attaching / detaching operation, and the cover for protecting the photosensitive drum can be automatically attached / detached to reduce the work such as maintenance service of the device. .

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an electrophotographic apparatus according to the present invention,
FIG. 2 is a side sectional view of the portion of FIG. 1, and FIGS. 3 to 5 are side views showing an attaching / detaching operation of the process unit with respect to the apparatus main body. 1 ... Photosensitive drum, 2 ... Developing device, 3 ... Cleaner, 4 ... Process unit, 5 ... Device body, 10 ... Transfer device, 20 ... Supporting device, 63 ... Roller, 64 ... Cam surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-59462 (JP, A) JP-A-58-198054 (JP, A) Actual opening 57-110564 (JP, U) Actual opening Sho-59- 89355 (JP, U) JP 58-54392 (JP, B2)

Claims (1)

[Claims] 1. A unit having a drum-shaped image carrier, a developing device for developing a latent image formed on the image carrier, and a cleaner for cleaning the surface of the image carrier after transferring the developed image. It is attachable to and detachable from the main body of the electrophotographic apparatus in a direction substantially perpendicular to the axial direction of the image carrier, and at the first position where the surface of the image carrier of the unit is exposed and at the second position where the image carrier is covered. A movable cover is provided in the unit, and the device main body is operated to move the cover in parallel in the apparatus main body in association with the mounting and dismounting operation of the unit in the attachment / detachment direction to cover the surface of the image carrier. Alternatively, the electrophotographic apparatus is characterized in that means for opening the image carrier is provided, and after the image carrier is covered with the cover, the image carrier portion of the unit is pulled out of the main body of the apparatus.