JPS6360477A - Image flow preventing method for image forming device - Google Patents

Abstract

PURPOSE:To eliminate a thin layer forming substance contained in a paper powder together with a cleaning agent fine powder, by a cleaning means, and to effectively prevent an image flow by applying the cleaning agent fine powder which is apt to be scraped down by the cleaning means, to the surface of an image carrying body. CONSTITUTION:An untransferred toner, namely, a residual toner on a photosensi tive drum 10 is cleaned by a cleaning device 26 such as a cleaning blade, etc. A cleaning agent applying device 28 is provided between the cleaning device 26 and an electrification corotron, and a fine powder of 0.3-0.4mum of polyvinylidene fluoride, polymethyl metacrylate, etc., is supplied so as to become a thin layer on the photosensitive drum 10 by a brush of polypropylene, 'Kanekaron(R)', 'Rayon(R)', etc., or by a porous sponge, etc. This fine powder has a high hardness and has such a characteristic as it is eliminated easily by the cleaning device 26. In this way, an electric resistance value of the surface of an image carrying body does not fall, therefore, an image flow can be prevented effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing image deletion in an image forming apparatus, and more particularly to a method for preventing image deletion in an electrophotographic copying machine.

In a typical electrophotographic copying machine, a photosensitive drum made of an organic photoreceptor or amorphous selenium is uniformly charged to positive or negative polarity by a charging corotron, and then charged by a scanning exposure device. An electrostatic latent image corresponding to the original is formed on the photosensitive drum.

The electrostatic latent image on the photosensitive drum is developed by a developing device,
The developed toner image is transferred onto a transfer paper by a transfer corotron and then fixed by a fixing device to obtain a hard copy. On the other hand, untransferred toner, that is, residual toner, on the photosensitive drum is removed by cleaning with a cleaning blade or the like.
Cleaning is performed by one device, and one copy cycle is completed.

Although the cleaning device sufficiently cleans the residual toner on the photosensitive drum, a thin layer may be formed on the photosensitive drum due to additives contained in paper dust generated from the transfer paper, and conventional cleaning methods (2) In I, the current situation is that the removal of this J layer is not sufficient.

Problems that Hatsushi is trying to solve As mentioned above, during the transfer of the toner image formed on the photoreceptor, paper dust from the transfer paper adheres to the photoreceptor, resulting in image deletion. There's a problem.

Paper powder consists of bulb fiber, which is the main raw material for paper, and talcum kaolin, which is added to improve the flexibility and opacity of paper.
It contains fillers such as calcium carbonate, and the bulb fibers are cleaned together with the residual toner on the photoreceptor using a cleaning device such as a cleaning blade made of ordinary urethane, etc. However, talc has low hardness, so it cannot be cleaned with a cleaning blade or other cleaning device. This cleaning device does not scrape it off, but instead softens it and forms a thin layer that is coated onto the surface of the photoreceptor. When such talc 11 is formed on the surface of the photoreceptor, the electric resistance value decreases due to moisture absorption and the like, and charge leaks, causing a problem in that the electrostatic latent image on the surface of the photoreceptor is disturbed and image deletion occurs.

The present invention has been made in view of these points, and its object is to provide a method for preventing image blurring in an image forming apparatus, which effectively prevents image blurring caused by paper dust on transfer paper. That's true.

Means for Solving the Problems In order to solve the problems of the prior art described above, the present invention provides an electrostatic latent image forming means around an image bearing member, a developing means for developing the electrostatic latent image, and a developing means for developing the electrostatic latent image. In an image forming apparatus equipped with a transfer means for transferring an image onto a transfer paper, and a cleaning means for cleaning residual toner remaining on the surface of the image carrier, an It9 layer on the surface of the image carrier due to paper dust of the transfer paper is provided. A cleaning agent fine powder is applied to the surface of the image carrier in order to prevent the formation of a thin layer, and the cleaning means removes the substance that forms a thin layer together with the cleaning agent fine powder. Provides a method for preventing device image flow.

Examples of the cleaning agent applied to the surface of the photoreceptor include polyvinylidene fluoride and polymethyl methacrylate.

Operation Since the cleaning agent fine powder applied to the surface of the image carrier has high hardness, the cleaning agent uses the property that it can be easily removed by cleaning means to remove the fine cleaning agent powder and the thin paper powder that adheres during the transfer process. The material forming the layer is removed from the surface of the image carrier by the cleaning means. This prevents the electrical resistance value of the surface of the image carrier from decreasing, so that image deletion can be effectively prevented.

EXAMPLES The present invention will now be explained in detail with reference to Examples.

Referring to FIG. 1, there is shown a schematic configuration diagram of an electrophotographic copying machine suitable for applying the present invention. The photosensitive drum 10 is uniformly charged by a charging corotron 12 to have a positive scratch property or a negative scratch property, and then a scanning exposure device 14 charges the original 1.
An electrostatic latent image corresponding to 6 is formed on the photosensitive drum 10. The electrostatic latent image on the photosensitive drum 10 is developed by a developing device 18 such as a magnetic brush developing device to form a toner image, and this toner image is transferred to a chute 2 by a transfer corotron 20.
The image is transferred onto a transfer paper 24 that is guided and fed by the paper 2 . The toner image transferred onto the transfer paper 24 is fixed by a fixing device (not shown) to obtain a hard copy. On the other hand, untransferred toner, that is, residual toner on the photosensitive drum 10 is cleaned by a cleaning device 26 such as a cleaning blade, and one copy cycle is completed.

28 is a cleaning agent application device, which is provided between the cleaning device 26 and the charging corotron 12, and is provided with a cleaning agent applying device of 0.3 to 0.00% of C1 polyvinylidene fluoride, polymethyl methacrylate, etc.
As shown in the figure, a fine powder of 4 μm is supplied onto the photosensitive drum 10 in a thin layer using a brush made of boria[]pyrene, Kanekalon, rayon, etc., or using a porous sponge or the like.

Therefore, when the toner image is transferred to the transfer paper 24 by the transfer corotron 20, paper dust from the transfer paper is transferred to the photosensitive drum 10.
Attach to. This paper powder consists of bulb fibers, which are the main raw materials of paper, and fillers such as talcum kaolin and calcium carbonate, which are added to improve the flexibility and opacity of the paper.

The bulb iIm is made of ordinary urethane or the like, and is cleaned together with the residual toner on the photosensitive drum 10 by a cleaning device 26 such as a leaning blade. However, since talc has low hardness, it cannot be scraped off by the cleaning device 26 such as a cleaning blade, and the remaining toner is removed. It becomes flexible and coats the surface of the photosensitive drum, forming a length of 1 m. Photosensitive drum 1
If such a thin layer of talc is formed on the surface of the photosensitive drum 10, the electrical resistance value of the surface of the photosensitive drum 10 decreases due to moisture absorption, etc., and the electric charge leaks, so that the electrostatic latent image formed on the photosensitive drum 10 This results in so-called image deletion, in which the electrostatic charge m@ is not formed in some places.

In the present invention, in order to improve this drawback, polyvinylidene fluoride, polymethyl methacrylate, etc.
Micron powder is supplied to the surface of the photosensitive drum 10 by a cleaning agent supply bag RF28. This fine powder has high hardness and is easily removed by the cleaning device 26. That is, the talc contained in the paper powder adhering to the photosensitive drum 10 during the transfer process is removed onto the photosensitive drum 10 by the cleaning device 26 together with the cleaning agent fine powder such as polyvinylidene fluoride fine powder or polymethyl methacrylate fine powder. This prevents the formation of a talc layer on the photosensitive drum 10.

Using a photosensitive drum coated with urethane resin,
Table 1 shows the results of a copy test conducted at high temperature and high humidity (30° C., 90%) using cleaning agents applied to the photosensitive drum 10 using various supplies.

As is clear from the results in Table 1, polyvinylidene fluoride and polymethyl methacrylate are commonly used as cleaning agents, and polypropylene, Kanekan,
Both rayon and sponge are suitable. As a comparative example, a copy test was conducted using a copying machine to which no cleaning agent was applied, and as a result, it was confirmed that image deletion occurred after 5,000 copies.

Effects of the Invention As detailed above, in the present invention, since the cleaning agent fine powder, which is easily scraped off by the cleaning means, is applied to the surface of the image holder, the cleaning agent fine powder is contained in the paper powder together with the cleaning agent fine powder. Since the thin layer forming substance can be removed by the cleaning means, image deletion can be effectively prevented.

[Brief explanation of drawings]

The accompanying drawing is a schematic configuration diagram showing an example of a copying machine to which the image deletion prevention method of the present invention can be applied. 10... Photosensitive drum, 12... Charging] eye contact, 14... Scanning exposure device, 16... (ii draft,
18...Developing device, 20...Transfer corotron, 24...Transfer paper, 26...Cleaning device (cleaning device), 28...
Cleaning agent application equipment.

Claims (1)

[Scope of Claims] Electrostatic latent image forming means around the image carrier, developing means for developing the electrostatic latent image, transfer means for transferring the developed image onto transfer paper, and remaining on the surface of the image carrier after transfer. In an image forming apparatus equipped with a cleaning means for cleaning residual toner, fine powder of a cleaning agent is applied to the surface of the image carrier in order to prevent paper dust from the transfer paper from forming a thin layer on the surface of the image carrier. A method for preventing image deletion in an image forming apparatus, characterized in that a substance forming a thin layer together with the cleaning agent fine powder is removed by the cleaning means.