JPH02275472A - Electrophotographic image forming device - Google Patents

Abstract

PURPOSE:To easily replace a photosensitive body without detaching process means arranged around a photosensitive body by moving a movable member associatively with the rotation of a rotary unit and separating a developing means from the photosensitive body while the upper part of the photosensitive body is open. CONSTITUTION:One rotary unit 38 consists of a cleaning means 16 and a process means above the photosensitive body 11 and is provided rotatably from the contact state with the photosensitive body 11 to a noncontact state so that the upper part of the photosensitive body 11 is open. Then the movable member 48 is provided between the rotary unit 38 and developing means 14 movably toward the developing means 14 associatively with the rotation of the rotary unit 38 and the developing means 14 is provided so that the developing means moves back from the state of contact with the photosensitive body 11 to the noncontact state against a spring. Consequently, when the photosensitive body 11 is replaced, the process means around it need not be detached and the replacement of the photosensitive body 11 is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic image forming apparatus, such as a laser printer, a copying machine, or a facsimile machine, which forms an image on paper using an electrophotographic process of charging, exposure, development, transfer, and cleaning.

2. Description of the Related Art Conventionally, in this type of apparatus, electrophotographic processing means such as charging means, developing means, and cleaning means are arranged so as to surround a photoreceptor, which is an image carrier.

Problem to be Solved by the Invention Therefore, when replacing a photoreceptor, which is a consumable item but has a long life, separately from other consumable items such as the process means, it is necessary to remove those process means one by one. I had to.

Furthermore, when these process means are removed, toner collected or attached to the process means may spill out of the machine.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to easily replace a photoreceptor without removing the process means surrounding the photoreceptor.

In order to achieve the above object of solving the problem, the present invention arranges some electrophotographic process means around a photoreceptor, and presses the developing means against the photoreceptor with a spring bias. In an electrophotographic image forming apparatus in which a developing means and a cleaning means are arranged on opposite sides of a photoreceptor, the cleaning means and the processing means above the photoreceptor constitute one rotating unit, The upper part of the photoreceptor is provided to be openable and rotatable from a contact state to a non-contact state with the photoreceptor, and a movable member is provided between the rotation unit and the developing means to rotate the rotation unit. The developing means is provided so as to be movable toward the developing means side in conjunction with the movement of the developing means, and the developing means is provided so as to be retractable from a contact state with the photoreceptor to a non-contact state against a spring.

-A Therefore, when the rotating unit is rotated, the rotating unit comes into a non-contact state with the photoconductor, and the upper part of the photoconductor is opened. At the same time, the movable member moves in conjunction with the rotation of the rotating unit, and the developing The means is brought into a non-contact state with the photoreceptor.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 10 shows an overall schematic configuration of a laser printer to which the present invention is applied. What is indicated by the reference numeral 10 in the figure is the main body of the apparatus. As shown in FIG. 11, the device main body 10 is composed of an earth structure 10a and a lower structure 10b, and the earth structure 10a is attached to the lower structure 10b so as to be openable and closable. Further, as shown in FIG. 10, a drum-shaped photoreceptor 11 that rotates clockwise in the figure is provided in the center of the main body 10 of the apparatus. Around the photoreceptor 11, a charging means 12, an optical writing means 13, a developing means 14, a transfer means 15, and a cleaning means 16 are arranged in order in the rotational direction. The photoreceptor 11, charging means 12, developing means 14, and cleaning means 16 are removably housed in an image forming case 17. One end 17a of the image forming case 17 is attached to the lower structure 10b around a shaft 18 so as to be rotatable counterclockwise in the figure.

Further, a paper feed cassette 19 is removably loaded on the right side of the apparatus main body 10 in the drawing. A paper feed roller 20 and a paper guide plate 21 are attached to the mounting portion of the paper feed cassette 19.
- Includes a paper feed section 23 having a pair of registration rollers 22 and the like. Further, the paper feed section 2
On the side opposite to 3, a conveying section 24, a fixing means 25, a pair of conveying rollers 2G, etc. are arranged in this order. Then, a pair of conveyance rollers 26 are connected to each other via a paper discharge path 27, and the apparatus main body 10 is
A paper discharge section 28 is provided above. Further, a paper discharge tray 29 is provided on the left side of the apparatus main body 10 in the figure.

When recording on paper using the electrophotographic method using the laser printer, the paper feed roller 20 is driven to sequentially feed the paper 30 from the paper feed cassette 19 in the direction of arrow a in the figure. Then, the paper 30 is guided and conveyed by the paper guide plate 21, and eventually the leading edge of the paper 30 is detected by a registration sensor (not shown). Then, the paper 3o stops with its leading edge hitting the registration roller 22, and
This prevents skew from occurring.

On the other hand, while rotating clockwise in the figure, the surface of the photoreceptor 11 is sequentially charged in a negative manner by the charging means 12, and then a laser beam is irradiated by the optical writing means 13 to form an electrostatic latent image on the surface. The electrostatic latent image is sequentially visualized by toner when it passes through the developing means 14. Then, by aligning the image with the resist and taking the timing, the above-mentioned paper 30 that was in contact with the above-mentioned registration roller 22 is moved onto the photoreceptor 1.
]. The image on the photoreceptor 11 is then transferred onto the paper 3o by the transfer means 15. After the transfer, the surface of the photoreceptor 11 is cleaned by the cleaning means 1G, and the static electricity is eliminated by the static elimination brush 31.

The toner removed from the photoreceptor 11 is sent into a collection tank 33 by a collection roller 32 and collected there. On the other hand, the paper 30 is sent to the fixing means 25 by the conveying section 241, and the transferred image is fixed by the fixing means 25. Then, the paper is sent out by the paper discharge roller 26 and selectively discharged to the wandering paper section 28 in the direction of the arrow or to the paper discharge 1 to ray 29.

If a jam occurs, open the upper structure 10a as shown in FIG. 11, and then open the shaft 10a as shown in FIG.
If the entire image forming case 17 is rotated counterclockwise about 8 as a fulcrum, the conveying section 24 on the lower side of the image forming case 17 will be opened.

Then, by extending the stand 35 connected to the image forming case 17 at the rotated position, the image forming case 17 is held at the rotated position. This makes it easier to remove jammed paper. The other end of the stand 35 is connected to the lower structure io.
Connect to b.

Incidentally, in the present invention, the photoreceptor 11 and some of the processing means around it are constructed as shown in FIGS. 1 to 4.

FIG. 1 schematically shows the overall construction of the image forming case 17, in which the photoreceptor 11.degree. cleaning means 16, developing means 14, etc. are assembled.

The image forming case 17 has a vertically elongated guide groove 34 on the side wall 17b.

The photoreceptor 11 is provided with a grip r 36 extending across both ends in the axial direction, and a shaft portion 37 protrudes outside of the grip 36 . Then, it is disposed approximately in the center of the image forming case 17, and the shaft portion 37 is inserted into the guide groove 34, and is detachably attached to the image forming case 17.

The cleaning means 16, the charging means 12, and the developing means 14 are arranged on opposite sides of the image forming case 17 with the photoreceptor 11 in between.

The cleaning means 16 and the charging means 12 located above the photoreceptor 11 are integrally formed to constitute a rotating unit 38. As shown in FIG.
The shaft portions 4o of the image forming case 17 are fitted together and rotatably attached to the image forming case 17.

Further, the rotation unit 38 is detachably attached to the image forming case 17 at a rotation position where the toner recovery port of the first recovery tank 33 faces upward. Therefore, the shaft portion 40 is
The flat surfaces 40a are provided in parallel in the vertical direction to form an elongated cross section. On the other hand, the bearing part 39 is provided with an attachment/detachment opening 41 by cutting out the ring part.

Then, the shaft portion 40 is guided in the elongated direction of the shaft portion 40 by the guide 42 of the attachment/detachment port 41, and is detachably attached to the bearing portion 39.

The developing means 14 includes a developing case 4 as shown in FIG.
3 and a developing roller 44. Supply roller 45, toner car 1-
By attaching the ridge 46 and the like, one unit is constructed. A pressure spring 47 is provided between the image forming case 17 and the image forming case 17.
is placed and urged toward the photoreceptor 11, and the developing roller 44 is pressed against the outer periphery of the photoreceptor 11.

Further, inside the image forming case 17, as shown in FIG. 1, a movable member 48 is disposed below the shaft portion 37 of the photoreceptor 11, and is provided so as to be movable to the left and right of the image forming case 17 in the figure. The movable member 48 is formed into a horizontally long plate shape, and is provided with a guide 49 for guiding the shaft portion 37 of the photoreceptor 11 on the side adjacent to the shaft portion 37 . The guide 49 is the movable member 4
8 gradually increases in height from one end 48a to the other end 48b,
It is composed of a sloped part 49a that is higher than the shaft part 37 of the photoreceptor 11, and a high part 49b that is connected to the end of the sloped part 49a. And the movable member 48.

Both ends 48a and 48b extend to the sides of the recovery tank 33 and the developing case 43.

A protrusion 50 is provided on the side surface of the collection tank 33 so as to be able to come into contact with the other end 48b of the movable member 48 when the rotation unit 38 rotates.

Also, a protrusion 51 is provided on the side surface of the developing case 43.
is provided, and when the movable member 48 moves, the movable member 48
It is provided so as to be able to come into contact with one end 48a of.

When the upper structure 10a is opened as shown in FIG. 11 and the rotation unit 38 is rotated counterclockwise as shown in FIG.
The charging means 12 and the like are connected to the photoreceptor 11 in a non-contact state.
The upper part of the photoreceptor 11 is opened.

When the rotating unit 38 rotates, the protrusion 50 comes into contact with the other end 48b of the movable member 48, and the movable member 48 moves to the right in the figure, and its one end 48a abuts against the protrusion 51 of the developing case 43. , the developing means 14 retreats against the pressure spring 47 and changes from a contact state with the photoreceptor 11 to a non-contact state.

Further, when the movable member 48 moves, the shaft portion 37 of the photoreceptor 11
moves upward along the guide groove 34 while moving the guide 49, so that the handle 36 protrudes from the image forming case 17,
The photoreceptor 11 is located at an attachment/detachment position with respect to the image forming case 17.

Thereby, the photoreceptor 11 can be attached and detached by holding the handle 36 without removing the rotating unit 38 and the developing means 14 arranged so as to surround the photoreceptor 11 one by one, and can be easily replaced. Since the rotation unit 38 and the developing means 14 are not removed, and the toner collection port (not shown) of the collection tank 33 faces upward when the rotation unit 38 is rotated, toner spillage is prevented when the photoreceptor is replaced. It disappears.

FIGS. 6 and 7 are schematic diagrams of an interlocking means in which the developing means 14 is retracted and the photoreceptor 11 is moved in conjunction with the rotation of the rotation unit 38 in another embodiment of the present invention.

In FIG. 6, the operation tQ of the movable member 48 from when the movable member 48 starts to move until the photoreceptor 11 moves as shown in FIG. 6(A), and the operation until the image means 14 moves. The quantity Q□ is configured so that Q□>Qz. As a result, as shown in FIG. 6(B), when the rotating unit 38 rotates, the developing means 14 first changes from a contact state with the photoreceptor 11 to a non-contact state via the movable member 48, and then As shown in FIG. 6(C), the photoreceptor 11 moves from the operating position of the main body of the apparatus and is located at the attachment/detachment position. Therefore, since the developing roller 44 has already been retracted from the photoreceptor 11 when the photoreceptor 11 is removed, it is possible to prevent the toner adhering to the developing roller 44 from being rubbed against the photoreceptor 11 and falling off.

In the above-described embodiment, the movable member 48 is formed in a plate shape, but it may be formed of links 53 and 54 as shown in FIG.

That is, the link 53 connects the collection tank 33 and the developing case 43.
along the sides and parallel to them. link 54
One end portion 54a is movably attached to the substantially central portion of the link 53, and the other end portion 53b is pressed against the lower side of the shaft portion 37 of the photoreceptor 11.

As a result, when the rotation unit 38 is rotated, as shown in FIG.
), the developing means 14 is retracted from the photoreceptor 11 by the link 53 to be in a non-contact state, and the photoreceptor 11 is moved by the link 54 to the attachment/detachment position.

FIG. 8 shows a rotation unit 38 in another embodiment of the present invention.
A schematic configuration of a holding means for holding the device in a rotating position with a stand 55 is shown. 1 recovery tank 33 as shown in FIG. 8(A)
and the image forming case 17 are connected by a stand 55 which can be folded in the middle. In this case, one end 55a of the stand 55 is removably attached to the recovery tank 33, or is simply pressed against it. Therefore, if the stand 55 is extended after rotating the rotation unit 38 as shown in FIG. 8(B),
The rotation unit 38 can now be held in that rotation position. Thereby, the photoreceptor 11 can be replaced safely.

In the embodiment described above, the rotating unit was held in the rotating position by the stand, but as shown in FIG. It is also possible to provide a structure in which engaging convex portions ``,'' are provided.

As a result, when the rotary L knit 38 is rotated, the front high-i engagement recess 56 and the engagement protrusion 57 are engaged with each other at the end of the rotation, and the L knit 38 is held in the rotated position. Therefore, photoreceptor 1
1 can be exchanged safely.

In the above-described embodiment, the rotating unit 38 has a unit structure including the cleaning means 16 and the charging means 12, but it may also have a unit structure including the toner cartridge 46 of the developing means 14.

SUMMARY OF THE INVENTION According to the present invention, when replacing a photoreceptor, it is possible to replace the photoreceptor without removing the surrounding process means one by one, thereby facilitating the replacement work of the photoreceptor. Since the photoreceptor and process means are not in contact with each other, when the photoreceptor is attached or removed,
It is possible to prevent the photoreceptor from being scratched or the toner from being rubbed by the photoreceptor and falling from the process means. Also,
Since there is no need to remove the process means, there is no chance of toner spilling outside the machine.

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention. FIG. 1 is a perspective view of the entire imaging case of a laser printer to which this invention is applied, and FIG. 2 is a top view of the laser printer equipped with the imaging case. A schematic configuration diagram of a structure. Figure 3 is a cross-sectional view of the imaging case, Figure 4 is a perspective view of a portion of the imaging case and collection tank, and Figure 5 is the upper structure of the laser printer when the rotation unit is rotated. A schematic configuration diagram is shown. FIGS. 6 and 7 show other embodiments of this invention,
Figure 6 (A), CB), (C) and Figure 7 (A), (
B) is a schematic configuration diagram showing the sequence of operations of the interlocking means in which the developing means retracts and the photoreceptor moves in conjunction with the rotating unit. 8(A) and 8(B) are other embodiments of the present invention, which are schematic configuration diagrams showing the operating order of the holding means for holding the rotating unit in its rotating position, and FIG. FIG. 7 is a partial perspective view of a recovery tank and an imaging case in another embodiment. Fig. 10 shows a laser printer to which the present invention is applied, and is a general schematic diagram of its internal mechanism. Fig. 11 is a perspective view of the laser printer with its upper structure opened. Fig. 12 shows a rotating image forming case. FIG. 2 is a schematic configuration diagram of the upper structure of the laser printer. 10... Apparatus main body 10a... Upper structure tob... Upper structure 11... Photoreceptor 12... ...Charging means 16...Cleaning means 38...
...Rotation unit 48...Movable member

Claims (1)

[Claims] Some electrophotographic processing means are arranged around a photoreceptor, and the developing means is pressed against the photoreceptor by a spring bias,
In an electrophotographic image forming apparatus in which a developing means and a cleaning means are arranged on opposite sides with a photoreceptor in between, the cleaning means and the processing means on the photoreceptor constitute one rotating unit. , the upper part of the photoreceptor is provided to be openable and rotatable from a contact state to a non-contact state with the photoreceptor, and a movable member is provided between the rotation unit and the developing means to rotate the rotation unit. An electrophotographic image forming apparatus, wherein the developing means is provided so as to be movable toward a developing means side in conjunction with the photoreceptor, and the developing means is provided so as to be retractable from a contact state with the photoreceptor to a non-contact state against a spring.