US4329413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic process capable of forming overlaid images and apparatus for carrying out the same
Assignee: Canon Inc
•
Filing: 1980-02-15
•
Granted: 1982-05-11
•
Expires: 2000-02-15
Abstract
Abstract The present invention is directed to process and apparatus for overlaying images making use of steps constituting a known electrophotographic process. The electrophotographic process on which the present overlay process depends is of the type in which a three-layered photosensitive member having an insulating covering layer as the top layer of the member is used. The surface of the insulating layer is charged with an electric charge simultaneously with an imagewise irradiation for a first image to be overlaid or during the time of a photo hysteresis resulted from the first image-forming irradiation being still present in the photoconductive layer of the photosensitive member. Then, AC discharging or charging with an electric charge of opposite polarity to that of the above electric charge is effected. Thereafter, an imagewise irradiation for second image is carried out to obtain an electrophotographically overlaid image from the first and second images.
Inventors
- 👤 Takashi Kitamura
- 👤 Michio Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:05
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/04018
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
A process for forming an overlay latent image comprising the steps of: applying a first image-forming irradiation onto a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an electrically insulating layer; applying a primary electric charge onto the surface of said insulating layer in relation to the change in conductivity of said photoconductive layer caused by said first image-forming irradiation; applying a corona discharge onto the surface of said insulating layer after applying the primary electric charge; and applying a second image-forming irradiation on said photosensitive medium thereby forming on the surface of said insulating layer an overlaid latent image from said first and second images.
Claim 2
Dependent Claim
117 words
A process for forming an overlay latent image comprising the steps of: applying a first image-forming irradiation onto a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an electrically insulating layer; applying a primary electric charge onto the surface of said insulating layer in relation to the change in conductivity of said photoconductive layer caused by said first image-forming irradiation; applying a corona discharge onto the surface of said insulating layer after applying the primary electric charge; and applying a second image-forming irradiation on said photosensitive medium thereby forming on the surface of said insulating layer an overlaid latent image from said first and second images.
Claim 3
Dependent Claim
22 words
A process according to claim 1, wherein said first and second images are positionally synchronized to form the overlaid electrostatic latent image.
Claim 4
Dependent Claim
32 words
A process according to claim 1, wherein said first image-forming irradiation is provided by an optical image of an original, while said second image-forming irradiation is provided by an optical beam spot.
Claim 5
Dependent Claim
21 words
A process according to claim 1, wherein said first and second image-forming irradiations are respectively provided by optical images of originals.
Claim 6
Dependent Claim
32 words
A process according to claim 1, wherein said first image-forming irradiation is provided by an optical beam spot, while said second image-forming irradiation is provided by an optical image of an original.
Claim 7
Dependent Claim
19 words
A process according to claim 1, wherein said first and second image-forming irradiations are provided by optical beam spots.
Claim 8
Dependent Claim
89 words
An electrophotographic process employing a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an insulating layer, which process comprises the steps of: charging the surface of said insulating layer during the time of a first image-forming irradiation or during the time of a photo hysteresis resulting from said irradiation being still present in said photoconductive layer; effecting AC discharging; and applying a second image-forming irradiation thereby forming an overlaid electrostatic latent image from said first and second images.
Claim 9
Dependent Claim
89 words
An electrophotographic process employing a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an insulating layer, which process comprises the steps of: charging the surface of said insulating layer during the time of a first image-forming irradiation or during the time of a photo hysteresis resulting from said irradiation being still present in said photoconductive layer; effecting AC discharging; and applying a second image-forming irradiation thereby forming an overlaid electrostatic latent image from said first and second images.
Claim 10
Dependent Claim
107 words
An electrophotographic process employing a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an insulating layer, which process comprises the steps of: charging the surface of said insulating layer during the time of a first image-forming irradiation or during the time of a photo hysteresis resulting from said irradiation being still present in said photoconductive layer; charging said surface with electric charge whose polarity is opposite to that of the above said charge; and applying a second image-forming irradiation thereto thereby forming an electrostatic latent image of an overlaid image from said first and second images.
Claim 11
Dependent Claim
107 words
An electrophotographic process employing a photosensitive medium essentially composed of an electrically conductive substrate, a photoconductive layer having substantially no charge injection property, and an insulating layer, which process comprises the steps of: charging the surface of said insulating layer during the time of a first image-forming irradiation or during the time of a photo hysteresis resulting from said irradiation being still present in said photoconductive layer; charging said surface with electric charge whose polarity is opposite to that of the above said charge; and applying a second image-forming irradiation thereto thereby forming an electrostatic latent image of an overlaid image from said first and second images.
References Cited (Backward Citations)
US4071361A
Cited
US3904408A
Cited
US3730709A
Cited
US3813243A
Cited
US3871878A
Cited
US4052206A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |