Patent US4314237A successfully refreshed from Google Patents.
US4407918A
Expired / Lapsed
US
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Electrophotographic process and apparatus for making plural copies from a single image
Assignee: Olympus Corp
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Filing: 1982-02-16
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Granted: 1983-10-04
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Expires: 2002-02-16
Abstract
Abstract A photosensitive member is formed by applying on an electrically conductive substrate, a first photoconductive layer sensitive to a visible light, an insulating charge retentive layer, and a second photoconductive layer sensitive to ultraviolet light, successively in this order. At first the photosensitive member is uniformly charged to a negative polarity, while the photosensitive member is uniformly exposed to the visible light. Then an image of a document to be copied is projected while the photosensitive member is charged to a positive polarity. After that the photosensitive layer is uniformly exposed to the visible light and finally the photosensitive member is uniformly exposed to the ultraviolet light. In this manner, an electrostatic charge image having high contrast and resolution is formed in the photosensitive member by means of charges which are stably trapped across the charge retentive layer. By repeating development and transfer for the same and single charge image once formed in the photosensitive member a number of copies having excellent image quality can be printed.
Inventors
- 👤 Eiichi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:33
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/14; G03G5/142; G03G5/144; G03G13/00; G03G13/04; G03G13/045; G03G5/02; G03G5/04; G03G5/043; G03G5/0436; G03G5/047; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
169 words
An electrophotographic process for forming at least one copy of a document by means of an electrophotographic photosensitive member including an electrically conductive substrate, a first photoconductive layer applied on the substrate, a charge retentive layer made of electrically insulating material and applied on the first photoconductive layer and a second photoconductive layer applied on the charge retentive layer, comprising the step of projecting an image of the document to be duplicated onto the photosensitive member with the aid of a first light to which the second photoconductive layer is substantially insensitive, but the first photoconductive layer is sensitive, while the photosensitive member is charged; the step of uniformly exposing the photosensitive member to said first light, said exposing step being effected after said image projecting step; and the step of uniformly exposing the photosensitive member to second light to which said second photoconductive layer is sensitive, whereby an electrostatic charge image is formed in said photosensitive member by means of electrostatic charges trapped across said charge retention layer.
Claim 2
Dependent Claim
169 words
An electrophotographic process for forming at least one copy of a document by means of an electrophotographic photosensitive member including an electrically conductive substrate, a first photoconductive layer applied on the substrate, a charge retentive layer made of electrically insulating material and applied on the first photoconductive layer and a second photoconductive layer applied on the charge retentive layer, comprising the step of projecting an image of the document to be duplicated onto the photosensitive member with the aid of a first light to which the second photoconductive layer is substantially insensitive, but the first photoconductive layer is sensitive, while the photosensitive member is charged; the step of uniformly exposing the photosensitive member to said first light, said exposing step being effected after said image projecting step; and the step of uniformly exposing the photosensitive member to second light to which said second photoconductive layer is sensitive, whereby an electrostatic charge image is formed in said photosensitive member by means of electrostatic charges trapped across said charge retention layer.
Claim 3
Dependent Claim
37 words
A process according to claim 1, further comprising prior to the image projecting step the step of charging the photosensitive member in one polarity and the step of uniformly exposing the photosensitive member to the first light.
Claim 4
Dependent Claim
25 words
A process according to claim 2, wherein said charging step in one polarity and the uniform exposing step with the first light are effected simultaneously.
Claim 5
Dependent Claim
27 words
A process according to claim 2, wherein said charging step in one polarity and uniform exposing step with the first light are effected successively in this order.
Claim 6
Dependent Claim
28 words
A process according to claim 2, wherein said charging effected simultaneously with the image projecting step is carried out by a D.C. corona charger of the other polarity.
Claim 7
Dependent Claim
23 words
A process according to claim 2, wherein said charging effected simultaneously with the image projecting step is performed by an A.C. corona charger.
Claim 8
Dependent Claim
28 words
A process according to claim 2, wherein said charging effected simultaneously with the image projecting step is performed by an A.C. corona charger biased in the other polarity.
Claim 9
Dependent Claim
26 words
A process according to claim 2, wherein said uniformly exposing step with the second light is effected after said uniformly exposing step with the first light.
Claim 10
Dependent Claim
27 words
A process according to claim 2, wherein said uniformly exposing step with the second light is effected simultaneously with said uniformly exposing step with the first light.
Claim 11
Dependent Claim
33 words
A process according to claim 2, wherein said uniformly exposing step with the second light is effected after the image projecting step, but prior to the uniformly exposing step with the first light.
Claim 12
Dependent Claim
23 words
A process according to claim 2, wherein said uniformly exposing step with the second light is effected simultaneously with the image projecting step.
Claim 13
Dependent Claim
28 words
A process according to claim 1, further comprising, after the image projecting step, but prior to the uniformly exposing step with the first light, a secondary charging step.
Claim 14
Dependent Claim
33 words
A process according to claim 12, wherein said secondary charging step is effected by a D.C. corona charger of polarity opposite to that of the charging carried out during the image projecting step.
Claim 15
Dependent Claim
19 words
A process according to claim 12, wherein said secondary charging step is carried out by an A.C. corona charger.
Claim 16
Dependent Claim
33 words
A process according to claim 12, wherein said secondary charging step is performed by an A.C. corona charger biased in polarity opposite to that of the charging effected during the image projecting step.
Claim 17
Dependent Claim
26 words
A process according to claim 12, wherein said uniformly exposing step with the second light is effected after said uniformly exposing step with the first light.
Claim 18
Dependent Claim
27 words
A process according to claim 12, wherein said uniformly exposing step with the second light is effected simultaneously with said uniformly exposing step with the first light.
Claim 19
Dependent Claim
33 words
A process according to claim 12, wherein said uniformly exposing step with the second light is effected after the secondary charging step, but prior to the uniformly exposing step with the first light.
Claim 20
Dependent Claim
23 words
A process according to claim 12, wherein said uniformly exposing step with the second light is effected simultaneously with the secondary charging step.
Claim 21
Dependent Claim
23 words
A process according to claim 12, wherein said uniformly exposing step with the second light is effected simultaneously with the image projecting step.
Claim 22
Dependent Claim
22 words
A process according to claim 1, further comprising, prior to the image projecting step, a step for primarily charging the photosensitive member.
Claim 23
Dependent Claim
21 words
A process according to claim 21, wherein the photosensitive member is exposed to the second light during said primary charging step.
Claim 24
Dependent Claim
31 words
A process according to claim 21, wherein said charging during the image projecting step is carried out by a D.C. corona charger of polarity opposite to that of the primary charging.
Claim 25
Dependent Claim
21 words
A process according to claim 21, wherein the charging during the image projecting step is effected by an A.C. corona charger.
Claim 26
Dependent Claim
31 words
A process according to claim 21, wherein the charging during the image projecting step is effected by an A.C. corona charger biased in polarity opposite to that of the primary charge.
Claim 27
Dependent Claim
26 words
A process according to claim 21, wherein said uniformly exposing step with the second light is effected after said uniformly exposing step with the first light.
Claim 28
Dependent Claim
27 words
A process according to claim 21, wherein said uniformly exposing step with the second light is effected simultaneously with said uniformly exposing step with the first light.
Claim 29
Dependent Claim
33 words
A process according to claim 21, wherein said uniformly exposing step with the second light is effected after the image projecting step, but prior to the uniformly exposing step with the first light.
Claim 30
Dependent Claim
23 words
A process according to claim 21, wherein said uniformly exposing step with the second light is effected simultaneously with the image projecting step.
Claim 31
Dependent Claim
19 words
A process according to any one of the preceding claims, wherein said first and second lights have different wavelengths.
Claim 32
Dependent Claim
20 words
A process according to claim 30, wherein said first light is visible light and said second light is ultraviolet light.
Claim 33
Dependent Claim
25 words
A process according to any one of claims 1 to 29, wherein said first and second lights have the same wavelength but have different intensities.
Claim 34
Dependent Claim
51 words
A process according to claim 1, further comprising a developing step for repeatedly developing the electrostatic charge image once formed in the photosensitive member with toner to form toned images and a transferring step for repeatedly transferring the toned images onto successive image receiving members to form a plurality of copies.
Claim 35
Dependent Claim
32 words
A process according to claim 1, wherein said image projecting step and the uniformly exposing steps with the first and second lights are effected from the side of the second photoconductive layer.
Claim 36
Dependent Claim
41 words
A process according to claim 1, wherein at least one of the image projecting step, the uniformly exposing step with the first light, and the uniformly exposing step with the second light is effected from the side of the conductive substrate.
Claim 37
Dependent Claim
74 words
An electrophotographic photosensitive member for use in an electrophotographic process according to claim 1, comprising a substrate made of electrically conductive material; a first photoconductive layer applied on said conductive substrate; a charge retentive layer made of electrically insulating material and applied on said first photoconductive layer; and a second photoconductive layer applied on said charge retentive layer which is substantially insensitive to the first light to which the first photoconductive layer is sensitive.
Claim 38
Dependent Claim
24 words
A photoconductive member according to claim 36, wherein said first and second photoconductive layers are exclusively sensitive to the first and second lights, respectively.
Claim 39
Dependent Claim
21 words
A photosensitive member according to claim 36, wherein said first photoconductive layer is sensitive both to the first and second lights.
Claim 40
Dependent Claim
35 words
A photosensitive member according to claim 36, wherein said first photoconductive layer has a rectifying property in which a charge of given polarity can freely move through the first photoconductive layer while it is dark.
Claim 41
Dependent Claim
33 words
A photosensitive member according to claim 36, wherein said first photoconductive layer is formed by an evaporated film of material selected from the group consisting of Se, Se alloy, CdS and amorphous silicon.
Claim 42
Dependent Claim
33 words
A photosensitive member according to claim 36, wherein said first photoconductive layer is formed by dispersing in a solution fine grains of material selected from the group consisting of CdS, ZnO and TiO.
Claim 43
Dependent Claim
16 words
A photosensitive member according to claim 36, wherein said first photoconductive layer is made of polyvinylcarbazole.
Claim 44
Dependent Claim
61 words
A photosensitive member according to claim 36, wherein said first photoconductive layer is formed by a composite photoconductive layer including a charge generating layer made of material selected from the group consisting of Se-Te, amorphous silicon, and CdS, and a charge transferring layer made of material selected from the group consisting of polyvinylcarbazole, parylene, anthracene, fluorene, polyvinyltetracene, 2,4,7-trinitro-9-fluorenone, dinitroanthracene and tetracyanopyrene.
Claim 45
Dependent Claim
45 words
A photosensitive member according to claim 36, wherein said charge retentive layer is formed by a polymer film made of material selected from the group consisting of fluorine-containing resin, polyester resin, polycarbonate resin, urethane resin, epoxy resin, polyethylene resin, cellulose acetate, and vinyl chloride resin.
Claim 46
Dependent Claim
34 words
A photosensitive member according to claim 36, wherein said charge retentive layer is formed by a polymer film made by glow discharge polymerization of material selected from a group consisting of styrene and para-xylene.
Claim 47
Dependent Claim
35 words
A photosensitive member according to claim 36, wherein said charge retentive member is formed by an inorganic thin film of material selected from the group consisting of SiO 2 and Ta 2 O 3 .
Claim 48
Dependent Claim
28 words
A photosensitive member according to claim 36, wherein said charge retentive member is formed by a thin film of p-xylene resin obtained by thermal decomposition of a dimer.
Claim 49
Dependent Claim
25 words
A photosensitive member according to claim 36, wherein said charge retentive layer is formed by a thin film of p-xylene obtained by gas phase polymerization.
Claim 50
Dependent Claim
20 words
A photosensitive member according to claim 36, wherein said second photoconductive layer is formed by a thin film of polyvinylcarbazole.
Claim 51
Dependent Claim
21 words
A photosensitive member according to claim 36, wherein said second photoconductive layer is formed by dispersing organic pigment in a binder.
Claim 52
Dependent Claim
13 words
A photosensitive member according to claim 50, wherein said organic pigment is phthalocyanine.
Claim 53
Dependent Claim
26 words
A photosensitive member according to claim 36, wherein said second photoconductive layer is formed of a thin film of naphthalene thiophene obtained by glow discharge polymerization.
References Cited (Backward Citations)
US4335194A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |