JPS6133193B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a screen photoreceptor (hereinafter also simply referred to as a screen) that has fine openings and is used to modulate ion flow, colored particles (toner/ink), etc.
The present invention relates to a cleaning device.

Since the image forming apparatus using the screen photoreceptor does not directly develop the screen, there is no need to clean the screen to remove residual toner every time development and transfer are completed, unlike conventional plate-shaped photoreceptors. However, if the cleaning device continues to be used for a long time without acting on the screen, harmful substances such as oxides due to corona discharge, floating toner, and dust will adhere to the screen, resulting in a decrease in charging potential and resolution. This is undesirable as it causes a drop in image quality. Therefore, it is necessary to provide a cleaning device to the screen to prevent the harmful substances from accumulating on the screen.

However, since the above-mentioned screens are generally made of weak materials such as thin metal fibers or metal plates as a base, they are made by pressing conventional elastic plates (blades).
It is not preferable to use a cleaning device that performs rubbing with strong pressure. Therefore, such screen cleaning devices include (i) one that uses a fur brush, (ii) one that sprays compressed air, (iii) one that combines the above (i) and (ii), and (iv) one that uses a blow brush. Cleaning devices such as those that apply electrostatic force have been proposed. By arranging these cleaning devices facing the screen and cleaning the screen, accumulation of the above-mentioned harmful substances can be prevented and a great effect can be obtained in terms of image formation. However, since the cleaning device described above requires a complicated configuration, the main body of the image forming device itself becomes large.
It is not suitable for devices whose goal is to miniaturize the device.
Furthermore, since the screen itself has a weak structure as described above, there is a risk that the screen surface may be deformed or the photoconductive layer may be damaged.

The purpose of the present invention is to solve the above-mentioned problems caused by installing the conventional cleaning device, and further to simplify the device having a screen, improve the durability of the screen itself, and downsize the cleaning device and make it easier to handle. It's about getting ease.

The present invention, which achieves the above objects, is applied to electrophotography in which a new latent image is formed on a chargeable member by modulating the ion flow using an electric field formed on a screen.
A fixing member is disposed on the surface of the photoreceptor that moves in the electrophotographic method, and a cleaning device and a device involved in forming a latent image are detachably attached to the fixing member. When a device involved in latent image formation is attached to form an image and the screen needs to be cleaned, the device involved in latent image formation is removed from the fixing member, a cleaning device is attached to the fixing member, and the screen is cleaned. This is a cleaning device for cleaning.

The shape of the screen may be a flat plate or a drum; in the former case, the latent image is formed by moving back and forth, and in the latter case, the latent image is formed while rotating in one direction. Further, as the fixing member, a shaft-shaped member or a guide member provided within the main body of the apparatus can be used. The cleaning device preferably has a brush means, a wall means surrounding the brush means, and a suction means for sucking air within the wall means for cleaning the screen. The cleaning device does not need to be large enough to operate over the entire width of the screen, and by moving it in the axial direction of the screen along the fixing member, the entire screen can be sufficiently cleaned. Furthermore, by configuring the cleaning device as described above, the cleaning device can be miniaturized, which makes the device easy to carry and is effective in terms of handling and operation. Therefore, it becomes possible for a service person to carry one cleaning device and clean the screens of multiple devices. On the other hand, devices involved in latent image formation include a corona discharger, an optical means, a chargeable sheet conveying means, an insulating drum, etc. arranged near the screen.

The above-mentioned present invention was made in consideration of the characteristics of harmful substances such as toner, dust, and oxides that accumulate on the screen after long-term use. This means that there is no need to remove it by cleaning, and for this reason the screen is designed to be cleaned when necessary. With the above configuration, the screen is not constantly rubbed by the cleaning device, so the screen surface is not rubbed more than necessary, and as a result, damage to the screen can be prevented as much as possible and the durability of the screen can be improved. Furthermore, since the fixing member is used for mounting both the device involved in latent image formation and the cleaning device, space within the device can be effectively utilized, making it possible to downsize the entire device. In the present invention, the term "removal of the cleaning device and the device involved in latent image formation" from the fixed member means both the case of completely removing the device from the main body of the device and the case of disposing it by sliding it to a predetermined position.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

FIG. 1 is a cross-sectional view of the device showing the first embodiment. In the figure, 1 is a screen, and as shown in the partially enlarged cross-sectional view of FIG. A photoconductive member 3 and a surface insulating layer 4 are disposed so as to be exposed on one side, and the screen 1 is constructed with the insulating layer facing the outside of the drum. For details, see Japanese Patent Application Laid-Open No. 51
Since it is in Publication No. 341, detailed explanation will be omitted.

The screen 1 rotates in the direction of the arrow, is uniformly charged by a first corona discharger 5, then charged to a polarity opposite to the first by a second corona discharger 6, and subjected to image exposure, and Furthermore lamp 7
By uniformly exposing the entire surface, a primary latent image corresponding to the original image is formed on the screen. The primary latent image on the screen 1 modulates the corona ions from the modulating corona discharger 8 onto the insulating drum 9. The secondary latent image formed on the insulating drum 9 by the above modulation is developed by a developing device 10,
This developer is transferred to the transfer paper 11 at the transfer material position, the residual toner is removed by the cleaning device 12, and the potential is made uniform by the static eliminator 13, and the developer reaches the modulation position.

In addition, 14 in the figure is the rotation center axis of the screen, 15
1 is a rotation center axis of an insulating drum, 16 is a transfer material storage set, and 17 is a fixing device.

In this embodiment, the insulating drum 9 is extracted along the rotating shaft 15, and a screen cleaning device is installed in place of the rotating shaft at a position opposite to the screen. FIG. 3 is a sectional view showing the state in which the cleaning device 18 is attached to the insulated drum position as described above, in which 19 is a container constituting the wall of the cleaning device, 20 is a fur brush, and 21 is for rotating the fur brush 20. The motor 22 is a scraping rod that removes harmful substances adhering to the fur brush 20 by applying the brush 20 with the rod 22. Further, the container 19 is connected to an air pump means (not shown) via a pipe 23, and the air inside the container 19 is exhausted to the outside of the container via the pipe 23. For this reason, by providing a filter member 24 at the outlet of the container 19 as shown in the figure, various substances removed from the fur brush 20 are transferred to the filter member 24.
It becomes possible to accumulate In the figure, reference numeral 25 denotes an opening provided in the container 19, through which the central shaft 15 of the insulating drum is passed, and the drum is disposed opposite to the screen 1.

In the embodiment shown in FIG. 3, only the air flow by the air pump means works in the vicinity of the fur brush 20, but the cleaning effect can be improved by actively applying the air flow in the direction of the brush 20 through the screen as shown by the chain line. It is effective for Such a supplementary air flow may be created by inserting a duct into the screen drum only during cleaning. Alternatively, as shown in FIG. 4, the dust-proof air introduced into a container 26 surrounding the screen 1 for dust-proofing is guided to the modulation position in the same way as during modulation, or especially to the modulation position, and is blown against the fur brush 20 arranged above. It's okay. As shown in FIG. 4, the air may be introduced into the container 26 by providing an opening in the container, or by providing an opening in the rotating shaft of the screen and introducing the air into the container 26 from this opening. It is also possible to guide the air to.

By cleaning the screen 1 while blowing wind from the side opposite to the fur brush 20, it is possible to effectively prevent dust, etc. that fly when the brush comes into contact with the screen from going around to the opposite side of the screen from cleaning. can. Further, as the air pump used in the cleaning device, a vacuum cleaner, a compressor, or a pump P (FIG. 4) for forming an air flow to the screen may be used. Furthermore, as shown in FIG. 4, a pipe 23 and a pipe 27 shown in FIG. 4 may be connected as an air circulation system to circulate air and clean the screen.

FIG. 5 shows a perspective view of FIG. 3 above. In the figure, 28 is a belt stretched between the rotation time of the motor 21 and the brush 20, and the cleaning device is connected to the rotating shaft 2.
The screen is cleaned by reciprocating the screen 5 in the direction of the arrow.

In the embodiment shown in FIG. 6, the present invention is applied to a copying apparatus that forms a secondary latent image on a chargeable sheet such as insulating paper, and the figure shows a sectional view of the apparatus. The screen used in the apparatus is the same as that shown in FIG. 1 above, and explanations of latent image formation and screen configuration will be omitted.

The apparatus shown in the figure is a copying apparatus in which an original image is exposed on a screen while the original table moves.The screen 29 has the same structure as the screen 1 and rotates about an axis 30 in the direction of the arrow. A first corona discharge is applied to the screen by a corona discharger 31, and a second corona discharge is applied by a discharger 32. Simultaneously with this second corona, the image of the document 34 on the document table 33 is illuminated by the lamp 35 and exposed onto the screen via the first fixed mirror 36, the lens, and the second fixed mirror 38. Screen 29 is further exposed to light across the entire surface by lamp 39, so that a primary latent image is formed on screen 29. The screen 29 is further rotated and at the modulation position, the primary latent image modulates the corona ions from the modulating discharge device 40 onto the insulating paper, forming a secondary latent image on the insulating paper. The insulating paper is stored in a cassette 41, sent out by a delivery roller 42, and sent to a modulation position via a register roller 43.

A conveying device 45 having belt means for conveying the insulating paper conveyed from the cassette 41 close to the screen 29 is provided at the modulation position.
The conveyance device 45 includes guide rails 46a and 46b.
It is arranged in such a way that it can be pulled out toward the front. The insulating paper on which the secondary latent image has been formed at the modulation position is developed by a developing device 47, fixed by a fixing device 48, and discharged from the device.

When the cleaning device of the present invention is applied to the above device, the insulating paper conveying device 4 at the modulation position
5 is pulled out along the guide rails 46a, 46b, and in place of the device 45, a cleaning device 49 is also disposed along the guide rails 46a, 46b. Figure 7 shows the state in which the cleaning device is installed as described above.
51 is a container of a cleaning device, 51 is a fur brush, 52 is a scraping rod, and 53 is an opening provided in the container 50. The opening is connected to a suction means (not shown), and removes toner, dust, oxides, etc. in the container 50. The air stream containing harmful substances is drawn out of the container through the opening.

As described above, according to the present invention, since the cleaning device does not constantly act on the screen, there is no possibility of damage due to frictional rubbing. In addition, since the cleaning device is installed in the main body of the device in place of another device in use only when necessary, the space inside the device can be used effectively and the device can be made smaller. Furthermore, with the above configuration, one cleaning device can clean the screens in a plurality of devices, making it possible to demonstrate its power in maintenance and servicing of the device bodies.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a copying apparatus to which the present invention is applied;
Fig. 2 is a partially enlarged sectional view of the screen used in the device shown in Fig. 1, Fig. 3 is a sectional view of the cleaning device showing an embodiment of the present invention, Fig. 4 is a sectional view of the screen side, and Fig. 5 is an embodiment. FIG. 6 is a perspective view of a cleaning device applied to the apparatus, FIG. 6 is a sectional view of a copying device according to another embodiment, and FIG. 7 is a sectional view when the cleaning device is installed. In the figure, 1, 29... Screen, 9... Insulating drum,
15... Rotating shaft, 18, 49... Cleaning device, 19, 50... Container, 20, 51... Fur brush, 22, 52... Scraping rod, 23, 27
... Pipe, 45 ... Conveying device, 46a, 46b
...It is a guide rail.

Claims (1)

[Scope of Claims] 1. In a cleaning device for a screen photoconductor used in electrophotography that modulates ion flow using an electric field formed on a screen photoconductor to form a new latent image on a chargeable member, A fixing member is placed against the
A cleaning device and a device involved in latent image formation are configured to be removably attached to the fixed member, and during image formation, the device involved in latent image formation is attached to the fixed member so as to face the surface of the photoreceptor. When cleaning the screen photoreceptor, the device involved in forming the latent image is removed from the fixing member, and a cleaning device is attached to the fixing member so as to face the photoreceptor surface, and the screen photoreceptor is cleaned by the cleaning device. A screen photoreceptor cleaning device characterized by: 2. The screen photoreceptor is drum-shaped, the device involved in latent image formation is an insulated drum that rotates in the same direction as the photoreceptor at the modulation position, and the fixing member is the central axis of rotation of the insulated drum. A cleaning device for a screen photoreceptor according to claim 1. 3. The screen photoconductor is drum-shaped, and the device involved in latent image formation is a conveyance device that conveys the chargeable sheet to the photoconductor at a modulation position, and the fixing member is a device that positions the conveyance device at a predetermined position. 2. The screen photoreceptor cleaning device according to claim 1, wherein the screen photoreceptor cleaning device is a guide means provided therein.