JPS6252864B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention is applicable to copying machines, facsimile machines, etc.
The present invention relates to a paper dust removal device that removes paper dust attached to unused paper before starting an image forming process.

When making a copy in a conventional copying machine or the like, first, copy paper stored in a paper feed cassette or the like is taken out by a paper feed roller. Thereafter, the copy paper is conveyed by a conveyance device to a photoreceptor drum, which is an image bearing member on which a toner image is formed, and after the toner image is transferred onto the copy paper by a transfer device, the copy paper is peeled from the photoreceptor drum and transferred to a fixing device. It's here to stay. On the other hand, after the transfer is completed, the photosensitive drum reaches a cleaning device and residual toner is removed. However, unused copy paper conveyed to the transfer device has paper dust attached to it, and the paper dust adheres to the photoreceptor drum side during transfer, so the cleaning device cleans the paper dust as well as the residual toner. It happens. For this reason, in the case of blade-shaped cleaning devices made of urethane, etc., which have been frequently used in recent years, and which scrape off residual toner by sliding in contact with the photoreceptor drum, if paper dust adheres to the tip of the blade, cleaning failures occur, and each time The disadvantage is that the tip of the blade must be cleaned, making maintenance complicated. Also, when using a printing machine, paper dust may adhere to the original plate when printing an image.
There is a problem in that the original plate is damaged.

This invention was made based on the above circumstances, and before starting the image forming process of a copying machine, printing machine, etc.
By removing paper dust adhering to paper, it is possible to prevent paper dust from adhering to the image forming device, reducing the need to clean the cleaning blade of a copying machine and the original plate of a printing machine, and improving operability. You can try to improve it. The purpose is to provide a paper dust removal device.

An embodiment of the present invention will be described below with reference to FIG. A paper feed cassette 10, which is a paper storage device provided in a copying machine main body (not shown), stores copy paper 11, which is paper. A paper feed roller 12 is provided above the paper feed cassette 10 and is brought into contact with the copy paper 11 during paper feeding. A conveying roller 13 constitutes a conveying device together with a guide plate 14, and conveys the copy paper 11 taken out from the paper feed cassette 10 to the photosensitive drum 16, which is an image carrier. This photosensitive drum 16 includes a transfer device 17 provided around it, a charging device (not shown),
An image forming device 18 is formed together with an exposure device, a developing device, a blade-shaped cleaning device, and the like.
Furthermore, a paper powder suction roller 21 made of silicone rubber is provided in a conveying path 20 extending from the paper feed cassette 10 to the image forming apparatus 18, and is made of silicone rubber and rolls into contact with the copy paper 11 being conveyed. And the paper powder adsorption roller 21 is
A corona charger 22 to which a voltage of about 1.5 [kV] is applied applies an electrical charge to the surface, and around it, a rotatable peeling claw 23 that peels off the copying machine 11 and a paper dust suction roller 21 attract the paper dust. A cleaning blade 26 that removes the paper dust 24
A cleaning section 27 is provided.

Next, we will discuss the effect. Upon the start of copying, the photosensitive drum 16 of the image forming device 18 is rotated in the direction of arrow S, and a charging process, an exposure process, and a developing process are sequentially performed to form a toner image. On the other hand, on the side of the paper feed cassette 10, the paper feed roller 12 is lowered to a position where it comes into contact with the copy paper 11, and the uppermost copy paper 11 is fed in the direction of arrow t. The copy paper 11 is then conveyed to a conveyance roller 13 and conveyed to a photosensitive drum 16 on which a toner image is formed.
1 is a paper powder suction roller 21 rotated in the direction of arrow U.
come into contact with. Further, the surface of the paper powder adsorption roller 21 is charged with an electric charge of about 200 [V] by a corona charger 22. Therefore, when the copy paper 11 comes into contact with the paper dust suction roller 21 during conveyance, the copy paper 11 generates dielectric polarization due to the electric charge on the surface of the paper dust suction roller 21, and is electrostatically attracted to the paper dust suction roller 21. After that, when the copy paper 11 reaches the peeling position, it is peeled off by a peeling claw 23 which is rotated in the direction of the arrow w and whose leading end slides into contact with the paper powder suction roller 21 . However, the paper dust 24 adhering to the surface of the copy paper 11 is separated from the copy paper 11 and remains on the surface of the paper dust absorption roller 21. The remaining paper dust 24 is then removed by a cleaning blade 26 as the paper dust suction roller 21 rotates.
The copy paper 11 from which the paper dust 24 has been removed is then conveyed to the photosensitive drum 16 by the conveyance roller 13.
After the toner image is transferred by the transfer device 17, it is fixed by a fixing device (not shown) to complete a copy image. On the other hand, after the transfer is completed, the photosensitive drum 16 reaches a cleaning device (not shown) as it rotates, and residual toner is removed therefrom.

With this configuration, it is possible to remove the paper dust 24 from the copy paper 11 before the copy paper 11 reaches the image forming device 18, and the paper dust 24 is attached to the photosensitive drum 16 during the transfer of the toner image. This reduces the amount of fouling of the blade of the cleaning device for removing residual toner, reduces the frequency of cleaning, and improves operability. Further, since the paper dust 24 is constantly removed from the paper dust suction roller 21 by the cleaning section 27, the efficiency of suctioning the paper dust 24 on the copy paper 11 is not reduced.

Note that this invention is not limited to the above-mentioned embodiments, and can be modified in various ways. For example, the image forming apparatus is not limited to one used in a copying machine, and the paper can also be used in facsimile machines, printing machines, etc., on which images are formed. Paper dust may be removed. In addition, the magnitude of the applied voltage and the amount of charge applied to the charging device that applies electrical charges to the paper powder suction roller are arbitrary. It may be one that utilizes charging. Further, the position of the charging device and the paper powder adsorption device can be arbitrary as long as it is in front of the image forming device, and as in another modification shown in FIG.
The paper powder suction roller 28a constituting the holder may be made of a charging member such as silicone rubber, and may be charged by a charging device such as the corona charger 22. In this way, since one of the conveyance rollers 28 is made up of the paper dust adsorption roller 28a, there is no need to provide any means for adsorbing paper dust in addition to the conveyance roller 28, and space can be saved. . Further, the material of the paper powder suction roller may be any material such as a conductor or a dielectric material as long as the surface has an electrical charge.

As explained above, according to the present invention, paper dust attached to the paper can be electrostatically removed before it reaches the image forming apparatus by bringing the paper into contact with the paper dust suction roller having an electrical charge on the surface. There is no possibility of paper dust adhering to the image forming apparatus and staining the image forming apparatus as in the conventional case. Therefore, in the case of copying machines, etc., there is no possibility of paper dust adhering to the blade-shaped cleaning device for removing residual charges, resulting in poor cleaning, and the frequency of cleaning is reduced, and in the case of printing machines, etc. Paper dust is not attached to the original plate, and the life of the original plate can be extended. Further, since paper dust is constantly removed by the cleaning section from the paper dust suction roller that electrostatically attracts paper dust, there is no fear that the efficiency of suctioning paper dust from paper will be reduced. Furthermore, as shown in another modification, if the conveying roller also serves as a paper dust suction roller, there is no need to provide a new paper dust suction means, and space can be saved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the invention, and FIG. 2 is a sectional view showing another modification of the invention. 10... Paper feed cassette, 11... Copy paper, 12... Paper feed roller, 13... Conveyance roller, 16... Photosensitive drum, 17... Transfer device, 18... Image forming device, 21
...Paper powder adsorption roller, 22...Corona charger, 2
3... Peeling claw, 24... Paper dust, 27... Cleaning section, 28... Conveyance roller.

Claims (1)

[Scope of Claims] 1. In an apparatus in which an image is obtained by transferring an image on an image carrier to a paper supplied from a paper storage device, a charging member provided between the paper storage device and the image carrier A paper dust suction roller comprising: a paper dust suction roller; a conveyance roller comprising a paper dust suction roller and an opposing roller that nip and convey the paper; and a corona charger that applies a corona charge to the paper dust suction roller. removal device. 2. The paper dust removing device according to claim 1, wherein the paper dust suction roller comes into contact with a cleaning section that removes the attracted paper dust.