US4675265A
Expired / Lapsed
US
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Electrophotographic light-sensitive element with amorphous C overlayer
Assignee: Fuji Electric Co Ltd
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Filing: 1986-03-25
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Granted: 1987-06-23
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Expires: 2006-03-25
Abstract
Abstract Electrophotographic light-sensitive elements according to the invention comprise (a) a conductive support; (b) a photoconductive layer; and (c) a surface protective layer. The conductive support is formed in a sheet-like or cylindrical shape from any suitable conductive material, and acts as an electrode of the light-sensitive element as well as acting as a physical support. The photoconductive layer comprises amorphous hydrogenated silicon having a high absorption efficiency and photoconductivity. The a-Si:H of a photoconductive layer may contain other elements such as fluorine, carbon, nitrogen and germanium, and may be doped with elements belonging to groups III and V of the periodic table. The surface protective layer is the outermost layer of an electrophotographic light-sensitive element according to the invention, and imparts resistance to environmental conditions. The surface protective layer comprises hydrogenated amorphous carbon, and may additionally contain silicon, nitrogen, oxygen or fluorine. The percentage of hydrogen can vary from 1 to 60 mole percent depending upon the conditions under which the surface layer is formed. Preferably, hydrogen is between 10 and 40 mole percent.
Inventors
- 👤 Toyoki Kazama
- 👤 Koichi Aizawa
- 👤 Kiyoto Yamaguchi
- 👤 Kenichi Hara
- 👤 Toshiyuki Iijima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:03
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/08; G03G5/082; G03G5/08214
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
103 words
An electrophotographic light-sensitive element comprising a conductive support having provided thereon in sequence: (a) a photoconductive layer comprising amorphous silicon; and (b) a surface protective layer comprising hydrogenated amorphous carbon, wherein the concentration of hydrogen atoms in the surface protective layer is from 1 atom percent to 60 atom percent; wherein said amorphous carbon is mainly bonded in a four-coordinate diamond structure such that the surface protective layer is chemically resistant and has good mechanical strength, and wherein said surface protective layer has a thickness sufficient to provide humidity resistance but not so great as to result in a significant loss of sensitivity.
Claim 2
Dependent Claim
103 words
An electrophotographic light-sensitive element comprising a conductive support having provided thereon in sequence: (a) a photoconductive layer comprising amorphous silicon; and (b) a surface protective layer comprising hydrogenated amorphous carbon, wherein the concentration of hydrogen atoms in the surface protective layer is from 1 atom percent to 60 atom percent; wherein said amorphous carbon is mainly bonded in a four-coordinate diamond structure such that the surface protective layer is chemically resistant and has good mechanical strength, and wherein said surface protective layer has a thickness sufficient to provide humidity resistance but not so great as to result in a significant loss of sensitivity.
Claim 3
Dependent Claim
25 words
An electrophotographic light-sensitive element according to claim 1, wherein the surface protective layer comprises hydrogenated amorphous carbon containing from 10 to 40 atom percent hydrogen.
Claim 4
Dependent Claim
20 words
An electrophotographic light-sensitive element according to claim 2, wherein the amorphous carbon contains from 15 to 36 atom percent hydrogen.
Claim 5
Dependent Claim
50 words
An electrophotographic light-sensitive element according to claim 2, wherein α 2 /α 1 , is greater than 0.8, α 1 being the absorption coefficient of the surface layer at 2920 cm -1 , and α 2 being the absorption coefficient of the surface protective layer at 2960 cm -1 .
Claim 6
Dependent Claim
21 words
An electrophotographic light-sensitive element according to claim 2, wherein the surface layer has a thickness of from 0.005 to 1.0 μm.
Claim 7
Dependent Claim
31 words
An electrophotographic light-sensitive element according to claim 2 further comprising a buffering layer, said buffering layer comprising amorphous silicon and being located between the photoconductive layer and the surface protective layer.
Claim 8
Dependent Claim
25 words
An electrophotographic light-sensitive element according to claim 6, wherein the amorphous carbon of the surface protective layer contains from 15 to 36 atom percent hydrogen.
Claim 9
Dependent Claim
25 words
An electrophotographic light-sensitive element according to claim 6, wherein the buffering layer is selected from hydrogenated amorphous silicon carbide and hydrogenated oxygenated amorphous silicon carbide.
Claim 10
Dependent Claim
28 words
An electrophotographic light-sensitive element according to claim 8, wherein the carbon concentration of the buffering layer increases from the photoconductive layer side to the surface protective layer side.
Claim 11
Dependent Claim
21 words
An electrophotographic light-sensitive element according to claim 8, wherein the buffering layer has a thickness of from 0.03 to 1 μm.
Claim 12
Dependent Claim
25 words
An electrophotographic light-sensitive element according to claim 6, wherein the buffering layer is selected from hydrogenated amorphous silicon nitride and hydrogenated oxygenated amorphous silicon nitride.
Claim 13
Dependent Claim
28 words
An electrophotographic light-sensitive element according to claim 11, wherein the nitrogen concentration of the buffering layer increases from the photoconductive layer side to the surface protective layer side.
Claim 14
Dependent Claim
21 words
An electrophotographic light-sensitive element according to claim 11, wherein the thickness of the buffering layer is from 0.05 to 1.0 μm.
Claim 15
Dependent Claim
17 words
An electrophotographic light-sensitive element according to claim 6, wherein the buffering layer comprises hydrogenated amorphous silicon oxide.
Claim 16
Dependent Claim
18 words
An electrophotographic light-sensitive element according to claim 6, wherein the buffering layer comprises hydrogenated amorphous silicon oxide carbide.
Claim 17
Dependent Claim
19 words
An electrophotographic light-sensitive element according to claim 1, wherein the surface protective layer comprises hydrogenated amorphous carbon containing oxygen.
Claim 18
Dependent Claim
20 words
An electrophotographic light-sensitive element according to claim 16, wherein the surface protective layer comprises less than 40 atom percent hydrogen.
Claim 19
Dependent Claim
21 words
An electrophotographic light-sensitive element according to claim 16, wherein the surface protective layer contains from 0.1 to 5 atom percent oxygen.
Claim 20
Dependent Claim
53 words
An electrophotographic light-sensitive element according to claim 1, wherein the surface protective layer is selected such that the band gap energy of the surface protective layer is between 0.2 eV lower than the band gap energy of the photoconductive layer and 0.6 eV higher than the band gap energy of the photoconductive layer.
Claim 21
Dependent Claim
22 words
An electrophotographic light-sensitive element according to claim 19, wherein the surface protective layer has a refractive index of from 1.7 to 2.8.
Claim 22
Dependent Claim
25 words
An electrophotographic light-sensitive element according to claim 6, wherein the surface protective layer has a band gap energy of from 2.0 eV to 3.2 eV.
Claim 23
Dependent Claim
22 words
An electrophotographic light-sensitive element according to claim 21, wherein the surface protective layer has a refractive index of from 1.7 to 2.8.
Claim 24
Dependent Claim
31 words
An electrophotographic light-sensitive element according to any one of claims 1, 2, 6, 16, 19 and 21 further comprising a blocking layer located between the conductive support and the photoconductive layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |