Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Process of making radiation-sensitive product
Reexamination Certificate
2002-06-27
2004-06-22
Goodrow, John L. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Process of making radiation-sensitive product
C118S719000, C118S7230IR, C427S574000
Reexamination Certificate
active
06753123
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process, and an apparatus, for manufacturing an electrophotographic photosensitive member having on a conductive substrate a photoconductive layer comprised of amorphous silicon (hereinafter “a-Si”) and a surface layer comprised of amorphous carbon which contains hydrogen (hereinafter “a-C:H”).
2. Related Background Art
In electrophotographic apparatus such as copying machines, facsimile machines and printers, a copy is taken in the following way: Using a photosensitive member comprising a conductive substrate and formed thereon a photoconductive layer comprised of a-Si, the surface of the photosensitive member is uniformly electrostatically charged by corona charging, roller charging, fur brush charging or magnetic-brush charging, and then exposed to light reflecting from an image to be copied (original) or laser light or LED light corresponding to modulated signals of that image, to form an electrostatic latent image on the surface of the photosensitive member. Then, a toner having been charged to a polarity opposite to that of the latent image is made to adhere to the latent image to perform development to form a toner image, and this toner image is transferred to a copying paper or the like.
In such electrophotographic apparatus, the toner remains partly on the surface of the photosensitive member, and hence such residual toner must be removed. The residual toner is commonly removed through a cleaning step making use of a cleaning blade, a fur brush or a magnet brush.
In electrophotographic apparatus available in recent years, toners having a smaller average particle diameter and a lower melting point than ever have come to be used in order to achieve higher image quality of printed images and achieve energy saving. In particular, with advancement of digitization of electrophotographic apparatus, the demand on image quality is more and more leveled up, so that even image defects having ever been tolerable have come to be deemed questionable.
The cause of the occurrence of melt adhesion or filming (of toner) which may cause such image defects has not been elucidated in detail, but its occurrence is roughly estimated in the following way.
In the cleaning step, for example, any frictional force acting between the photosensitive member and the part rubbing against it (rubbing part) may cause a phenomenon of chattering at the part of contact, where the effect of compression against the photosensitive member surface may become higher, so that the residual toner may strongly be pressed against the photosensitive member surface to cause the melt adhesion or filming. In addition, with an increase in process speed for the image formation of electrophotographic apparatus, the relative speed between the rubbing part and the photosensitive member increases, and hence this tends to more cause the melt adhesion or filming.
As countermeasures for solveing the above problem, a method is effective in which, as disclosed in, e.g., Japanese Patent Applications Laid-open No. 11-133640 and No. 11-133641 (which correspond to U.S. Pat. No. 6,001,521), a layer of non-single-crystal carbon containing hydrogen is formed as a surface layer of a photosensitive member.
The a-C:H, as it is also called diamond-like carbon (DLC), has a very high hardness. Hence, it is tough to scratches and wear and has a peculiar solid lubricity, and hence it is considered to be an optimum material for preventing the melt adhesion or filming. In fact, it has been ascertained that, where an a-C:H film is formed on the surface of a photosensitive member, the melt adhesion or filming can effectively be prevented in various environments.
However, an electrophotographic photosensitive member having this a-C:H film at the surface is manufactured using a high-frequency plasma-assisted CVD system, there have been the following problems.
Usually, when, the high-frequency plasma-assisted CVD system is used, after the step of depositing the a-C:H, any by-product (polysilane) produced during the formation of photoconductive layers must be removed by dry etching or the like to clean the interior of a reactor.
However, the cleaning performed after the successive formation from the photoconductive layer up to the surface layer (a-C:H) may inevitably take a longer time than the cleaning performed after the successive formation from the photoconductive layer up to any conventional surface layer (e.g., a-SiC).
This is due to the fact that not only the by-product (polysilane) produced during the formation of photoconductive layers but also the a-C:H film remain in the reactor. The a-C:H film has properties of being etched with great difficulty, and hence a long cleaning time is taken to remove the a-C:H film. This has been a factor of increase in manufacturing cost.
As another problem, a-C:H film pieces may slightly remain in the reactor, and hence, where the next photosensitive member is formed using the same reactor, the a-C:H film pieces having slightly remained in the cleaning step may adhere to the substrate surface when the next deposited film is formed. This has been a factor of causing image defects.
Also in the case of a surface layer comprised of a-C:H with silicon added in a very small quantity (hereinafter “a-C:H(Si)”), the layer can be etched with difficulty like the a-C:H surface layer to cause the like problem.
SUMMARY OF THE INVENTION
The present invention has been made in order to solve such problems the related background art has had. Accordingly, an object of the present invention is to provide a process, and an apparatus, for manufacturing electrophotographic photosensitive members by which an electrophotographic photosensitive member having a photoconductive layer comprised of a-Si and a surface layer comprised of a-C:H or a-C:H(Si) can be manufactured in a good efficiency and at a low cost.
Stated specifically, the present invention provides a process for producing an electrophotographic photosensitive member having at least a first layer, a second layer and a conductive substrate, comprising the steps of forming said first layer in a first reactor having been evacuated, and forming said second layer in a second reactor having been evacuated,
wherein a source gas is decomposed by the use of a high-frequency power in each of said first reactor and said second reactor to deposit said first layer and said second layer on said conductive substrate,
said first layer comprises an amorphous material composed chiefly of silicon atoms; and
said second layer comprises an amorphous material composed chiefly of carbon atoms and contains hydrogen atoms.
The present invention also provides an apparatus for producing an electrophotographic photosensitive member having at least a first layer, a second layer and a conductive substrate, comprising at least a first reactor for forming said first layer and a second reactor for forming said second layer,
wherein a source gas is decomposed by the use of a high-frequency power in each of said first reactor and said second reactor to deposit said first layer and said second layer on said conductive substrate,
said first layer comprises an amorphous material composed chiefly of silicon atoms; and
said second layer comprises an amorphous material composed chiefly of carbon atoms and contains hydrogen atoms.
REFERENCES:
patent: 4897281 (1990-01-01), Arai et al.
patent: 4954397 (1990-09-01), Amada et al.
patent: 4957772 (1990-09-01), Saitoh et al.
patent: 5061511 (1991-10-01), Saitoh et al.
patent: 5273851 (1993-12-01), Takei et al.
patent: 5284730 (1994-02-01), Takei et al.
patent: 5314780 (1994-05-01), Takei et al.
patent: 5407768 (1995-04-01), Akiyama et al.
patent: 5455138 (1995-10-01), Okamura et al.
patent: 5480627 (1996-01-01), Takei et al.
patent: 5582944 (1996-12-01), Yamamura et al.
patent: 5624776 (1997-04-01), Takei et al.
patent: 5670286 (1997-09-01), Takei et al.
patent: 5817181 (1998-10-01), Okamura et al.
patent: 5849446 (1998-12-01), Hashizume et al.
patent: 5976745 (1999-11-01), Aoki et al.
pat
Hashizume Junichiro
Hosoi Kazuto
Okamura Ryuji
Fitzpatrick ,Cella, Harper & Scinto
Goodrow John L.
LandOfFree
Process and apparatus for manufacturing electrophotographic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and apparatus for manufacturing electrophotographic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and apparatus for manufacturing electrophotographic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3366368