JPS5827497B2 - Image holding member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image holding member for holding an electrostatic image and/or a toner image.

The image holding member according to the present invention is mainly used for electrophotography.

Image holding members conventionally used for electrophotography include electrophotographic photoreceptors and other image holding members.

Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied.

Typical electrophotographic photoreceptors include a photoreceptor that does not have an insulating surface layer on its surface, that is, a photoreceptor that usually has a photoconductive layer on a support, and a photoreceptor that has an insulating surface layer on its surface. Photoreceptors having a configuration are widely used.

The former photoreceptor is used in the most common electrophotographic process, i.e.
It is commonly used to form electrostatic images by charging and imagewise exposure.

The surface layer of the latter photoreceptor is provided for the purpose of protecting the photoconductive layer, improving the mechanical strength of the photoreceptor, improving dark decay characteristics, or being applied to a specific electrophotographic process. .

Representative examples of photoreceptors having such surface layers or electrophotographic processes using photoreceptors having surface layers are, for example, U.S. Pat.
JP 16429, JP 38-15446, JP 46-3713, JP 42-23910, JP 43-24748, JP JP 1977-1
It is described in Japanese Patent Publication No. 9747, Japanese Patent Publication No. 36-4121, etc.

A predetermined electrophotographic process is applied to the electrophotographic photoreceptor to form an electrostatic image, and this electrostatic image is developed with toner and made visible.

At this time, a bias voltage is usually applied to the developing device depending on the potential of the latent image holding member.

Some representative image bearing members will be described next.

An electrostatic image formed on the surface of an electrophotographic photoreceptor by subjecting the electrophotographic photoreceptor having a photoconductive layer to a predetermined electrophotographic process is usually developed with toner, and then the toner image is recorded on a predetermined paper or the like. transferred to the body.

In addition, in other electrophotographic processes, for example, Japanese Patent Publication No. 32-7115, Japanese Patent Publication No. 32-8204,
As stated in Japanese Patent Publication No. 43-1559,
In order to improve the repeatability of the electrophotographic photoreceptor, an electrostatic image formed on the electrophotographic photoreceptor is transferred to an electrostatic image holding member for toner development, and then the toner image is transferred to a recording medium.

Further, as other electrophotographic processes in which an electrostatic image is formed on an electrostatic image holding member in correspondence with an electrostatic image formed on an electrophotographic photoreceptor, for example, Japanese Patent Publication No. 4530320 and Japanese Patent Publication No. 48-5063 are disclosed. , JP-A No. 51-341, etc., an electrostatic image is formed on a screen-shaped electrophotographic photoreceptor having a large number of fine openings by a predetermined electrophotographic process, and this electrostatic image is By performing a corona charging treatment on the electrostatic image holding member through the electrostatic image holding member, the ion flow of the corona is modulated to form an electrostatic image on the electrostatic image holding member, which is then developed with toner and transferred to the recording medium. The process of forming the final image is mentioned.

According to other electrophotographic processes, a toner image formed on an electrophotographic photoreceptor or an electrostatic image holding member is not directly transferred to a recording medium, but is transferred to a toner image holding member, and then recorded from the toner image holding member. Transfers and fixes the toner image onto the body.

This process is particularly useful for forming color images or for high speed copying.

Recording media are usually highly flexible, such as paper or film, and for this reason, it is better to transfer a three-color image onto a recording media while accurately aligning the material, which causes almost no deformation. A more accurately aligned color image is formed by transferring a three-color image to a toner image holding member that can be formed using a toner image holding member, and then transferring the three-color image to a recording medium at once.

Further, it is effective for speeding up copying that the toner image is transferred to the recording medium via the toner image holding member.

In this way, the electrophotographic photoreceptor that is the image holding member, or the member that does not have a photoconductive layer and that holds an electrostatic image or a toner image, depends on the electrophotographic process to which it is applied. Appropriate electrical characteristics are required.

However, small portions of image holding members used in electrophotography are easily destroyed or pinholes are formed due to high voltage corona discharge, cleaning treatment, etc.

If a small portion is destroyed or a pinhole is generated in this way, so-called fogging will occur and the clarity of the image will be impaired.

Therefore, when a small portion is broken or a pinhole occurs, the image holding member cannot withstand further use.

Accordingly, the main object of the present invention is to provide an image holding member with excellent durability by substantially eliminating the influence caused by the occurrence of such pinholes.

The present invention provides an image holding member having a photoconductive layer and/or an insulating layer on a conductive layer, including an insulating layer on the back surface of the conductive layer, and wherein the conductive layer prevents destruction of the photoconductive layer and/or the insulating layer. The image holding member is characterized in that it is easily destroyed as a result of this destruction.

The conductive layer of the image holding member according to the present invention is set to be thin.

The conductive layer is destroyed as an upper layer such as a photoconductive layer and/or an insulating layer on top of the conductive layer is destroyed.

This significantly reduces various problems caused by pinholes caused by destruction of the upper layer, such as uneven charging and fog.

Next, among these, especially the relationship with fog will be explained with reference to the drawings.

FIG. 1 shows the case of a conventional image holding member.

An electrostatic image is formed on an image holding member composed of a photoconductive layer 1 and a conductive support 2.

The formed electrostatic image is developed with toner.

Bias development is usually performed from time to time.

FIG. 1 shows the state during this bias development.

Pinholes 10 are formed in the photoconductive layer due to external causes.

If bias development is performed in this state, the bias voltage will not be applied effectively and a clear image will not be obtained.

That is, the voltage applied between the conductive developer (carrier) and the conductive support 2 by the bias voltage source 4 is significantly affected by the developer carrier 3 that has entered the pinhole 10 formed in the photoconductive layer. be lowered.

This is because the conductive developer carrier directly contacts the conductive support at the pinhole area.

FIG. 2 shows a case where the image holding member according to the present invention is used.

The image holding member is composed of a photoconductive layer 1, a conductive layer 5, and an insulating member 6.

Since the conductive layer 5 is destroyed when the upper layer above the conductive layer 5 is destroyed, the general shape of the pinhole formed in this conductive holding member is as shown in 11. The holes reach the surface of the insulating member 60.

The destruction of the conductive layer may be simultaneous with the destruction of its sublayers, or it may be destroyed by a subsequent electrical or mechanical shock after the upper layer has been destroyed.

During bias development, the developer carrier that has entered the pin pole 11 is in contact with the insulating material, so the bias voltage applied from the bias voltage source 4 does not cause a voltage drop due to the developer carrier 3, and as a result, the electrostatic Toner adheres to the image according to its potential, forming a clear, fog-free image.

The conductive layer is a thin layer that is easily destroyed, and its thickness is approximately 1
000-10 rrgt, especially 200-20 mμ is suitable.

The conductive layer forming material is formed using various conductive materials.

Typical examples include aluminum, tin oxide,
Examples include indium oxide, copper, and iodized steel.

The conductive layer is usually formed by vapor deposition, but other methods such as chemical deposition or foil attachment may also be used.

In the experiment, the dark potential of the photoconductive layer was set to about 600V, the light potential to about 100V, and the bias voltage of the developer was set to 200V.
It was set to V.

At this time, most of the image holding members made by the method shown in FIG. 1 suffered from fogging due to damage to the photoconductive layer after approximately 50,000 copies were made, whereas most of the image holding members made by the method shown in FIG.
No fogging due to damage to the photoconductive layer occurred even after 10,000 copies were made.

The image holding member according to the present invention is similar to that shown in FIG.
For example, various configurations are taken.

For example, a support may be provided below the insulating member 6 of the image holding member shown in FIG.

Further, FIGS. 3 and 4 show other configuration examples of the image holding member of the present invention.

FIG. 3 shows an image holding member comprising an insulating layer 7, a photoconductive layer 1, a conductive layer 5, an insulating member 6 and a support 8. FIG.

The support body 8 may be omitted if necessary. FIG. 4 shows an image holding member composed of an insulating layer 7, a conductive layer 5, and an insulating member 6. As shown in FIG.

A support may be provided below the insulating member 6, if necessary.

These image holding members are applicable to each of the conventional electrophotographic processes described above, depending on their configuration.

The image holding member according to the present invention has a conductive layer and an insulating member, and in addition to the configuration described above, it may have a configuration including other components depending on the electrophotographic process to which it is applied. .

The insulating member is formed so as not to be damaged by an impact that would destroy the conductive layer.

When applying a bias voltage in bias development processing, for example, if there is a conductive support under the insulating member, the conductive layer and the support may be connected, or one side of the bias voltage may be applied to the support. may be applied.

The image holding member according to the present invention has excellent properties such as being able to be charged uniformly even if pinholes are partially formed, and furthermore preventing excessive dielectric breakdown caused by pinholes. It is particularly effective in terms of clear image formation and durability.

Various resins are usually used as the insulating member and the insulating layer forming material.

For example, materials such as polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, acrylic resin, polycarbonate, silicone resin, fluororesin, urethane resin, and epoxy resin can be used.

The thickness of the insulating layer is set according to desired characteristics.

Generally, when an insulating layer is added for the main purpose of protecting the image holding member, improving its durability, dark decay characteristics, etc., the insulating layer is relatively thin. The insulating layer provided in this case is relatively thick.

Usually, the thickness of the insulating layer is 0.1 to 90μ, especially 0.1μ to 90μ.
It is set to 1 to 45μ.

The support is formed from any material such as a metal plate such as stainless steel, copper, aluminum, or tin, paper, sheet, or resin film.

The photoconductive layer is S, Se, PbO and S, Se, Te, As.
, Sb, Pb, etc., or an inorganic photoconductive material such as an intermetallic compound is formed by vacuum deposition.

In addition, when using the sputtering method, ZnO1CdS, C
A photoconductive layer can also be formed by depositing a photoconductive material with a high melting point, such as dSe or TiO2, on the support.

When forming a photoconductive layer by coating, organic photoconductive materials such as polyvinylcarbazole, anthracene, and phthalocyanine, dye-sensitized or Lewis acid-sensitized products of these materials, and mixtures of these with insulating binders are used. obtain.

Also suitable are mixtures of inorganic photoconductors such as ZnO, CdS, TiO2, pbo, etc. with insulating binders.

Note that various resins are used as the insulating binder.

Although the thickness of the photoconductive layer depends on the type and characteristics of the photoconductive material used, it is generally 5 to 100 μm, particularly 10 to 50 μm.
degree is suitable.

[Brief explanation of drawings]

FIG. 1 shows a case where a conventional image holding member is subjected to bias development processing. FIG. 2 shows the case where the image holding member according to the present invention is subjected to bias development processing. FIGS. 3 and 4 each show one image holding member according to the present invention.
It is a mode. DESCRIPTION OF SYMBOLS 1... Photoconductive layer, 2... Conductive support, 3... Developer carrier, 4... Bias voltage source, 5... ... Conductive layer, 6 ... Insulating member, 7 ... Insulating layer, 8 ... Support, 1 O and 1 1 ... Pinhole.

Claims (1)

[Claims] 1 having a photoconductive layer and/or an insulating layer on the conductive layer,
In an image holding member that holds an electrostatic image and/or a toner image, an insulating layer is provided on the back side of the conductive layer, and when the photoconductive layer and/or the insulating layer are destroyed, the conductive layer is An image holding member characterized in that it is easily destroyed.