Charging apparatus and image forming apparatus

Abstract

The present invention provides a charging device, which has high durability, does not rust, etc., and even if some pollutants such as toner are attached, the control performance of the charging potential is hardly damaged, and the charging of the photoreceptor can be charged for a long time. Potential is stably controlled in an appropriate range, and the price is low. The charging device (24) includes: needle electrode (50), holding part (51), two cleaning parts (52a, 52b), supporting part (53), moving parts (54), shielding cover (55) and grid grid electrode (56). In the charging device (24), a nickel plating layer (70) containing polytetrafluoroethylene particles is formed on the surface of the grid electrode (56).

Description

technical field [0001] The present invention relates to a charging device and an image forming device. Background technique [0002] In electrophotographic image forming devices such as copiers, printers, and facsimile machines, a photoreceptor with a photosensitive layer containing a photoconductive substance formed on its surface is used as an image carrier, and the surface of the photoreceptor is charged and uniformly charged. , forming an electrostatic latent image corresponding to the image information through various imaging processes, and then developing the electrostatic latent image with a developer supplied from a developing device and containing toner to make it a visible image, and the visible image After being transferred to a recording material such as paper, heat and pressure are applied by a fixing roller to fix it on the recording material, thereby forming an image on the recording paper. [0003] In such an image forming apparatus, a charging device is use...

AI Technical Summary

Problems solved by technology

[0004] Among these grid electrodes, the wire grid electrode has the following problems that should be solved: it is easy to adhere to pollutants such as toner, and due to the adhesion of pollutants, it cannot fully exert the function of controlling the charged potential on the surface of the photoreceptor, thereby photosensitive The charged potential on the surface of the body will become uneven

At the same time, there is a problem that needs to be solved: the ability to control the charge potential on the photoreceptor becomes insufficient, and the charge potential on the surface of the photoreceptor becomes uneven, and the desired charge cannot always be stably imparted to the photoreceptor surface. electric potential

Due to the lack of smoothness of the etched section of the needle-shaped electrode, there are many edges for discharging at the front end of the needle-shaped part. Therefore, the discharge of each needle-shaped part will be uneven

As a result, the charging potential on the surface of the photoreceptor cannot be sufficiently controlled, and the charging potential on the surface of the photoreceptor becomes uneven.

[0010] In addition, iron-based metal materials such as stainless steel, which are used as needle-shaped electrode materials, have high durability on the one hand, but on the other hand, they have problems such as moisture in high-humidity environments and ozone generated by corona discharge during charging operations. The disadvantage of being easily oxidized

As long as the needle electrode is used for a long time, it is unavoidable to use it in a high-humidity environment, and contact with ozone, etc.

Therefore, in needle-shaped electrodes formed of metal materials such as stainless steel, corrosion occurs due to moisture in the air, ozone, etc., and its durability decreases.

At the same time, there are problems that should be solved: the ability to control the high voltage applied to the needle-shaped electrodes in order to generate corona discharge from the needle-shaped parts is reduced, and the charging potential on the surface of the photoreceptor becomes uneven, so that it cannot always be Stably imparts the desired charge potential to the surface of the photoreceptor

[0011] In addition, in the wire electrode, there are also the same problems that should be solved as the needle electrode: rust, corrosion, etc. due to the ozone generated by the corona discharge, and the charging potential on the surface of the photoreceptor becomes uneven.

That is to say, the needle-shaped electrode in JP-A-2004-4334 has the following disadvantages: after long-term use, pollutants such as toner will adhere, thereby making the charged potential on the surface of the photoreceptor more uneven.

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