Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Radiation-sensitive composition or product
Reexamination Certificate
1999-08-24
2001-04-17
Rodee, Christopher (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Radiation-sensitive composition or product
C430S056000, C399S111000, C399S159000
Reexamination Certificate
active
06218063
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having a photosensitive layer containing a specific compound. This invention also relates to a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
2. Related Background Art
Electrophotographic photosensitive members making use of organic photoconductive materials have greatly been improved in their sensitivity and durability (or running performance) as a result of the advancement of function-separated photosensitive members comprising a charge generation layer containing a charge-generating material and a charge transport layer containing a charge-transporting material which are superposed, and have been widely put into practical use.
Meanwhile, in recent years, photosensitive members having a broad spectral sensitivity ranging from visible to infrared wavelength regions are energetically developed so that copying machines can be made to have the function of writing by laser light. As a means for achieving such an object, it is known to use a charge generation layer formed of a charge-generating material having a sensitivity in the visible light region and a charge-generating material having a sensitivity in the infrared region which are mixed with each other or superposed in layers.
Printers to which electrophotography is applied are in wide use as terminal unit printers. These are chiefly laser beam printers having lasers as light sources. As the light sources, semiconductor lasers are used in view of the cost, the size of apparatus and so forth. Semiconductor lasers prevalingly used at present have an oscillation wavelength as long as 790 to 820 nm. Accordingly, electrophotographic photosensitive members having sufficient sensitivities in such a long-wavelength region are being developed, and, in order to improve sensitivity and running performance, it is known to use the charge transport layer formed of charge-generating materials which are mixed with each other or superposed in layers.
As a combination of an azo pigment with a phthalocyanine compound, Japanese Patent Application Laid-open No. 7-175241 disclose a photosensitive member making use of a specific azo pigment and an oxytitanium phthalocyanine; and Japanese Patent Application Laid-open No. 7-128888, a photosensitive member making use of a specific azo pigment and a gallium phthalocyanine.
These photosensitive members, however, are disadvantageous in that the properties of the respective charge-generating materials can not well be exhibited and, especially when used in a mixture, their potential variations become great during running as memory characteristics become poor. Use of the gallium phthalocyanine may result in a poor chargeability to cause image deterioration due to dots or fog. Also, it can not be said that the sensitivity itself in the visible and infrared regions are satisfactory.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the disadvantages the prior art has and to provide an electrophotographic photosensitive member having a high sensitivity, promising a high image quality and undergoing less potential variations.
Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus which employ such an electrophotographic photosensitive member.
The present invention provides an electrophotographic photosensitive member comprising a support and a photosensitive layer provided on the support;
the photosensitive layer containing a disazo pigment represented by the following Formula (1) or (2) and a hydroxygallium phthalocyanine.
wherein A
1
and A
2
may be the same or different and each represent a coupler residual group having a phenolic hydroxyl group.
wherein A
3
and A
4
may be the same or different and each represent a coupler residual group having a phenolic hydroxyl group.
The present invention also provides a process cartridge comprising the electrophotographic photosensitive member described above and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means, which are supported as one unit and being detachably mountable to the main body of an electrophotographic apparatus.
The present invention still also provides an electrophotographic apparatus comprising the electrophotographic photosensitive member described above, a charging means, an exposure means, a developing means and a transfer means.
REFERENCES:
patent: 5595845 (1997-01-01), Maeda et al.
patent: 5725985 (1998-03-01), Nealey et al.
patent: 0 715217 (1996-06-01), None
patent: 0 743561 (1996-11-01), None
patent: 0 823668 (1998-02-01), None
patent: 263007 (1993-10-01), None
patent: 128888 (1995-05-01), None
patent: 175241 (1995-07-01), None
Chemical Abstracts 123:97891, 1995.
Nakata Kouichi
Tanabe Kan
Tanaka Masato
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Rodee Christopher
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