JPS62201464A - Process unit for copying machine - Google Patents

Abstract

PURPOSE:To prevent a copy image from reduction in quality by arranging a recording paper carrier penetrated into a housing on the lower area of a photosensitive body. CONSTITUTION:When an upper half body 16 of a copying machine body 10 is coupled with a lower half body 17, carrying courses 13a, 13b are respectively connected to a carrying inlet 26a and a carrying outlet 26b of the housing 26 of a process unit 20 and the upper part 13a of the recording paper carrying course, the recording paper carrier 27 and the lower part 13b of the recording paper carrying course are respectively connected. Thereby, recording paper in a paper holder 14 of the copying machine body 10 is carried from the upper part 13a of the carrying course to the lower part 13b through the recording paper carrier 27 and then discharged to a tray 15 in the copying machine body 10. During the period, a toner image is transferred to the recording paper in a transfer room 24 of the housing 26.

Description

Detailed Description of the Invention 3. Detailed Description of II (Field of Industrial Application) The present invention relates to a process unit that is used in a small and lightweight copying machine and is detachable from the copying machine main body.

(Prior art) Recently, electrophotographic copying machines have been subject to deterioration due to use.
Alternatively, a copying machine has been developed in which a photoreceptor, a developing device, etc., which wear out with use, are integrated and configured to be detachable from the main body of the copying machine, thereby making it easy to replace consumables and the like. for example,
JP-A-59-61850 discloses a process unit that integrates a photoreceptor, a charging device, a developing device, and a cleaning device. The process unit is
It does not include a transfer device, and the transfer device is attached to the main body of the copying machine. The lower part of the unit is defined by a recording paper transport path formed by a gap between a transfer device attached to the copying machine main body and a photoreceptor housed in the unit.

In such a process unit, when the process unit is installed in a copying machine main body, the surface of the photoreceptor and the transfer device must be opposed to each other via the recording paper conveyance path. On the other hand, when the process unit is removed from the main body of the copying machine, in order to protect the surface of the photoreceptor or to prevent the toner inside the process unit from flying outside, it is necessary to remove the photoreceptor from the process unit. The process unit must be hermetically sealed so that it is housed within the housing. For this reason, the above-mentioned JP-A-59-
In the process unit disclosed in Publication No. 61850, a special drum cover is provided to cover the photoreceptor, and when installed in the copying machine main body, this cover is opened to expose the surface of the photoreceptor and face the transfer device. 5. Conversely, when the unit is removed from the main body of the copying machine, the surface of the photoreceptor is covered with this cover. Such a drum cover requires a complicated mechanism because it is opened and closed in a narrow space.

Also, the drum cover can be opened easily.

A user of the copying machine may accidentally touch the surface of the photoreceptor. When the drum cover is opened, toner may be scattered around.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide a 9N clean structure that prevents the user from accidentally touching the surface of the photoreceptor. Therefore, it is an object of the present invention to provide a process unit for a copying machine that does not cause the quality of copied images to deteriorate.

(Means for Solving the Problems) The present invention is a process unit that can be attached to and detached from a main body of a copying machine, and includes a photoconductor that is integrally fixed in the housing of the process unit, and
It includes a charging device, a developing device, a cleaning device, and a recording paper conveyance path that passes through the housing in an area below the photoreceptor.

This achieves the above objective.

(Example) Examples of the present invention will be described below.

As shown in FIGS. 1 and 2, a process unit 20 of the present invention is installed in, for example, an electrophotographic copying machine main body 10. As shown in FIGS. In the copying machine main body 10, an upper half 16 and a lower half 17 are rotatably supported by a pivot 19 with an upstream portion 13a and a downstream portion 13b of the recording paper conveyance path as boundaries. The process unit 20 of the present invention includes an upper half 16
It is installed by sliding it from the side.

The process unit 20 includes a photoreceptor drum 21 as a photoreceptor rotatably disposed in the center of a housing 26.
．． Charging device 22. Developing device 23. and cleaning 2
5, which are integrally fixed to the housing 26. The charging device 22 is located above the photosensitive drum 21. The developing device 23 is disposed downstream of the charging device 22 in the rotational direction of the photosensitive drum 21 . The cleaning device 25 is disposed upstream of the charging device 22 in the rotational direction of the photoreceptor drum 21 . A slit 26c is provided in the upper surface of the housing 26. The slit 26c is located between the charging device 22 and the developing device 23.

A transfer chamber 24 is formed in the lower part of the housing 26 . The transfer chamber 24 is located below the photosensitive drum 21. In the vicinity of the photosensitive drum 21 of the transfer chamber 24.

A recording paper conveyance path 27 is formed to penetrate the housing 26 . Therefore, the upstream side of the recording paper conveyance path 27 is connected to an inlet 26a formed in the housing 26, and the downstream side of the recording paper conveyance path 27 is connected to an outlet 26b formed in the housing 26.

The recording paper enters the housing 26 from the lower area of the developing device 23 along the recording paper conveyance path 27, receives the toner image there, and then moves from the housing 26 to the lower area of the cleaning device 25. transported. In order for the recording paper carried into the housing 26 from outside the housing 26 through the carry-in port 26a to have a toner image transferred thereon, it is smoothly carried out of the housing 26 from the second carry-out roller 26b. It is preferable that the outlet 26b be provided at a position appropriately higher than the outlet 26b (a position close to the photoreceptor drum 21).

An introduction plate 28 is provided on the upstream side of the recording paper conveyance path 27 . Further, a guide plate 29 is provided on the downstream side of the recording paper transport path 27. The introduction plate 28 is connected to the housing 26
It extends downstream from the lower edge of the loading bay 26a, and its downstream end is inclined upward so as to approach the photoreceptor drum 21. The lead-out plate 29 extends upstream from the lower edge of the outlet 26b. The upstream end of the guide plate 29 is also inclined upward so as to approach the photosensitive drum 21 .

The lifespan of the photosensitive drum 21 and the charging device 22 in the process unit 20 is approximately equal to the period required to consume the amount of toner stored in the developing device 23. Similarly, the capacity of the wandering toner tank in the cleaning device 25 is such that it can accommodate the waste toner generated within the above period.

An opening 24 a is formed in the lower surface of the transfer chamber 24 formed in the lower part of the housing 26 . The opening 24a communicates the inside of the transfer chamber 24 with the outside of the housing 26.

The opening 24a has a size that allows a transfer device 18, which will be described later, to enter therein. The opening 24a can be opened and closed by, for example, two seal members 24b, 24b.

The proximal end of each seal member 24b and 24b is connected to the opening 24
They are fixed to opposing peripheral edges of a, respectively, in a single-supported state. The tips of the seal members 24b and 24b overlap at the center of the opening 24a. As the seal member 24b.

A material 1 having light-shielding properties and visibility, such as a plastic film, is used.

Upper half 1 of the copying machine main body 10 rotating around a pivot 19
6, the process unit 20 can be attached to it as described above. A sliding document table 11 is disposed above the upper half 16. The document table 11 is.

It can slide in a direction perpendicular to the axis of the photoreceptor drum 210 to which it is attached. An optical system 12 is provided below the document table 11 . The optical system 12 images an image of a document placed on the document table 11 as the document table 11 moves.

The surface of the photosensitive drum 21 in the process unit 20 is exposed through the slit 26c of the housing 26.

A transfer device 18 is attached to the lower half 17 of the copying machine main body 10 at a position facing the photosensitive drum 21.

The transfer device 18 is connected to the process unit 20 when the upper half 16 and lower half 17 of the copying machine main body IO are connected.
In the transfer chamber 24, a sealing member 24 of the opening 24a is provided.
b and 24b while pushing open each seal member 2.
4b and 24b are in contact with the side surface of the transfer device 18. Therefore, the gap between the transfer device 18 and the opening 24a is closed by each sealing member 24b, and there is no possibility that external dust or the like will enter the transfer chamber 24 through the opening 24a.

What are the upper half 16 and lower half 17 of the copying machine main body 10?

The recording paper is separated by an upstream section 13a and a downstream section 13b of the conveyance path. When the upper half 16 and lower half 17 of the copying machine main body 10 are connected, these conveyance paths 13a and 13b communicate with an inlet 26a and an outlet 26b of the housing 26 of the process unit 20, respectively. As a result, the upstream portion 13a of the recording paper conveyance path, the recording paper conveyance path 27, and the downstream portion 13b of the recording paper conveyance path are communicated with each other. Therefore, the paper holder 14 of the copying machine main body 10
The recording paper inside can be discharged onto the tray 15 of the copying machine main body 10 after passing through the recording paper conveyance path 27 of the transfer chamber 24 from the R conveyance path 13a and the downstream portion 13b of the conveyance path. During this time, the toner image is transferred onto the recording paper in the transfer chamber 24 of the housing 26. This transferred toner image is fixed onto the recording paper by a fixing device 13c provided in the R feeding path 13b.

How to attach the process unit 20 to the main body IO of the copying machine.

This is done as follows. First, the upper half 16 of the copying machine main body 10 is rotated upward and separated from the lower half 17. In this state, the process unit 20 is attached to the upper half-rest 16. Next, this upper half body 16 is rotated downward and connected to the lower half body 17. in this case.

The sealing members 24b, 24b that close the transfer chamber 24 of the process unit 20 are pressed by the transfer device 18 attached to the lower half 17 of the copying machine main body 10 to open the opening 24a. The transfer device 18 includes each seal member 24b.

It enters into the transfer chamber 24 while slidingly contacting the transfer chamber 24b. and.

When the upper half 16 and the lower half 17 are connected, the transfer device 18 connects the photosensitive drum 21 across the recording paper conveyance path 27.
facing a predetermined position.

The copying operation of this copying machine is similar to that of a conventional electrophotographic copying machine, and is as follows.

The surface of the photosensitive drum 21 is uniformly charged by a charging device 22 in the process unit 20 . Next, document table 1
The image of the original placed on the photoreceptor drum 21 is exposed by the optical system 12, and an electrostatic latent image is formed on the surface of the photoreceptor drum 21.

The electrostatic latent image is developed with toner by the developing device 23.

On the other hand, the recording paper passes through the upstream portion 13a of the conveyance path and is introduced into the recording paper conveyance path 27 of the process unit 20.

At this time, the recording paper is guided by the introduction plate 28 and brought into contact with the photosensitive drum 21. The toner image on the photosensitive drum 21 is transferred onto recording paper by a transfer device 24. The recording paper on which the toner image has been transferred is guided by the guide plate 29 and is carried out of the housing 26 from the outlet 26b. and,
It passes through the downstream portion 13b of the B feeding path and is sent to the fixing device 13c.

Here, the toner image is fixed on the recording paper. The recording paper with the toner image fixed thereon is discharged onto the tray 15.

When the toner image is transferred to the recording paper, the photosensitive drum 2I is cleaned by a cleaning device 25 to remove residual toner from the surface thereof.

The life spans of the photosensitive drum 21 and the charging device 22 in the process unit 20 are set to be approximately equal.

Amount of toner in the developing device 23 and cleaning device 25
The amount of wandering toner inside is also set to correspond to the above-mentioned lifespan. Therefore, when the photoreceptor drum 21 and the like reach their service life limit, the upper half-hole 16 of the copying machine main body 10 is rotated upward, and the entire process unit 20 is slid in the axial direction of the photoreceptor drum 21, and the upper half-hole 16 is rotated upward. will be separated from. Then, a new process unit 20 is attached to the upper half 16. When the process unit 20 is removed from the upper half-rest 16, the tip ends of the seal members 24b and 24b are in an initial overlapping state due to their flexibility, and the opening 24a of the housing 26 is closed.

The process unit 20 of the present invention can also be applied to a copying machine whose main body 10 cannot be separated into an upper half 16 and a lower half 17. For a copying machine main body that cannot be separated into an upper half and a lower half, the process unit is attached to and removed from the copying machine main body by sliding in a direction perpendicular to the recording paper conveyance path in the copying machine main body. 3 to 5 show a process unit 20' of the present invention that can be attached to and detached from such a copying machine main body.

The process unit 20° has an opening 24a on one side in the sliding direction of a transfer chamber 24′ formed in a region below the photosensitive drum 21° within the housing 26′.

has been established. The opening 24a' is provided with seal members 24b'' and 24b made of the same material as in the previous embodiment.

are respectively supported on opposing peripheral edges of the opening 24a. The tips of the seal members 24b' and 24b' overlap at the center of the opening 24a'.

The opening 24a' is closed. On the inner surface of the transfer chamber 24'' facing the opening 24a'', there is a locking portion 18 of the transfer device 18''.
An engaging portion 24d' that can be engaged with b' (described later) is provided.

The transfer device 18'' is fixed to the ?31 copying machine main body 10' by a support member 18a''. The support member 183° supports one end of the transfer device 18'' in the longitudinal direction.

A locking portion 18b' is provided at the other end of the transfer device in the longitudinal direction of 18°.
is formed. The locking portion 18b'' can be engaged with the engaging portion 24d' inside the transfer chamber 24°.
The process unit 20' is fixed at a predetermined position relative to the copying machine main body 10'. The other configurations are the same as those of the previous embodiment, so the explanation will be omitted.

The process unit 20' is attached to the main body of the copying machine in the following manner. From the opening 24a'' of the housing 26', the locking portion 18b of the transfer device 18°.

The entire process unit 20' is moved into the main body 10' of the copying machine so that the process unit 20' is inserted. Due to this.

The sealing member 24b° that covers the opening 24a'' is the locking portion 18.
The transfer device 18'' is pushed open at the 'transfer chamber 24'.
to invade inside. At this time, the seal members 24b° and 24b′ come into contact with the outer surface of the transfer device 18° due to their own flexibility. And transfer equipment 8°
The locking part 18a' is the engaging part 24b' on the inner surface of the transfer chamber 24''.
By engaging with the process unit 20°, the process unit 20°
It is mounted at a predetermined position on the main body 10' of the copying machine.

In addition, the transfer chamber 2 of such a process unit 20゛
A member for guiding the transfer device 18° to a predetermined position may be provided within the transfer device 4.

(Effects of the Invention) As described above, in the process unit of the present invention, the recording paper conveyance path passing through the housing is formed in the lower area of the photoreceptor fixed in the housing, so that the photoreceptor is always inside the housing. Therefore, even when the process unit is removed from the main body of the copying machine, there is no risk that the photoreceptor will be exposed outside the housing. Therefore, there is no risk of accidentally touching the surface of the photoreceptor, and the quality of the resulting copy image will not deteriorate. Furthermore, there is no risk of the toner scattering around.

4. The one-wheel theory in the text Figure 1 is a longitudinal cross-sectional view of the process unit of the present invention installed in a copying machine body, and Figure 2 is a state in which the upper half of the copying machine body is rotated upward. FIG. 3 is a front view of a process unit in another embodiment of the present invention, and FIG.
The figure is a cross-sectional view thereof, and FIG. 5 is a cross-sectional view taken along the line ■-v in FIG. 4.

10, 10'... Copying machine body, 18.18' ・
...Transfer device.

20, 20'...process unit, 2L 21
'... Photosensitive drum, 22... Charging device, 23...
...Developing device, 24.24°...Transfer chamber, 24a,
24a'...opening, 24b, 24b'...
Seal member, 25...Cleaning device, 26.2
6°...housing, 27...recording paper conveyance path.

that's all

Claims (1)

[Claims] 1. A process unit that is removably attached to the main body of a copying machine, and includes a photoreceptor, a charging device, a developing device, and a cleaning device that are integrally fixed in the housing, and a lower area of the photoreceptor. A process unit for a copying machine, comprising: a recording paper transport path passing through the housing.