US4910555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic device with controlled exposed potential
Assignee: Koki Holdings Co Ltd
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Filing: 1988-11-07
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Granted: 1990-03-20
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Expires: 2008-11-07
Abstract
Abstract An electrophotographic device has a photosensitive element, an electrifier that forms a uniform electrostatic potential on the photosensitive element, and a light source for irradiating the photosensitive element to obtain an electrostatic latent image that has a reduced potential. A bias potential is applied to the photosensitive element after the latent image is formed, but before it is developed, so that the reduced potential of the latent image can be maintained at a constant level. With constant potentials existing on the photosensitive element, a printed image of high quality is obtained.
Inventors
- 👤 Osamu Namikawa
- 👤 Yasuo Kikuchi
- 👤 Minoru Seino
- 👤 Hiroshi Ueno
- 👤 Koji Doi
- 👤 Tsukasa Onose
- 👤 Shigenobu Katagiri
- 👤 Toshitaka Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:10
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/045
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
An electrophotographic device for obtaining a printed image comprising: a photosensitive element; first means for charging said photosensitive element with a first bias voltage to a electrostatic potential; means for irradiating said photosensitive element with light to obtain a latent image having a reduced potential over a portion of said photosensitive element; means for detecting said reduced potential; second means for charging said reduced potential with a second bias voltage so that said reduced potential is uniform over said portion of said photosensitive element; means for controlling said second bias voltage using said detected reduced potential; and means for developing said latent image to obtain said printed image.
Claim 2
Dependent Claim
108 words
An electrophotographic device for obtaining a printed image comprising: a photosensitive element; first means for charging said photosensitive element with a first bias voltage to a electrostatic potential; means for irradiating said photosensitive element with light to obtain a latent image having a reduced potential over a portion of said photosensitive element; means for detecting said reduced potential; second means for charging said reduced potential with a second bias voltage so that said reduced potential is uniform over said portion of said photosensitive element; means for controlling said second bias voltage using said detected reduced potential; and means for developing said latent image to obtain said printed image.
Claim 3
Dependent Claim
13 words
A device according to claim 1 wherein said illuminating means is a laser.
Claim 4
Dependent Claim
34 words
A device according to claim 1 wherein said first charging means includes a first electrifier and a first power supply and said second charging means includes a second electrifier and a second charging means.
Claim 5
Dependent Claim
14 words
A device according to claim 1 further including means for cleaning said photosensitive element.
Claim 6
Dependent Claim
14 words
A device according to claim 1 wherein said photosensitive element has a cylindrical shape.
Claim 7
Dependent Claim
19 words
A device according to claim 1 wherein said photosensitive element includes a photosensitive film disposed over a conductive layer.
Claim 8
Dependent Claim
19 words
A device according to claim 6 wherein said photosensitive element is amorphous selenium and said conductive layer is aluminum.
Claim 9
Dependent Claim
137 words
An electrophotographic device for obtaining a printed image comprising: a photosensitive element; first means for charging said photosensitive element with a first bias voltage to a electrostatic potential; means for irradiating said photosensitive element with light to obtain a latent image having a reduced potential over a portion of said photosensitive element; means for detecting said potentials on said photosensitive element; first means for controlling said first bias voltage using said detected potential so that said electrostatic potential is uniform over the surface of said photosensitive element; second means for charging said reduced potential with a second bias voltage so that said reduced potential is uniform over said portion of said photosensitive element; second means for controlling said second bias voltage using said detected potential; and means for developing said latent image to obtain said printed image.
Claim 10
Dependent Claim
137 words
An electrophotographic device for obtaining a printed image comprising: a photosensitive element; first means for charging said photosensitive element with a first bias voltage to a electrostatic potential; means for irradiating said photosensitive element with light to obtain a latent image having a reduced potential over a portion of said photosensitive element; means for detecting said potentials on said photosensitive element; first means for controlling said first bias voltage using said detected potential so that said electrostatic potential is uniform over the surface of said photosensitive element; second means for charging said reduced potential with a second bias voltage so that said reduced potential is uniform over said portion of said photosensitive element; second means for controlling said second bias voltage using said detected potential; and means for developing said latent image to obtain said printed image.
Claim 11
Dependent Claim
13 words
A device according to claim 8 wherein said irradiating means is a laser.
Claim 12
Dependent Claim
34 words
A device according to claim 8 wherein said first charging means includes a first electrifier and a first power supply and said second charging means includes a second electrifier and a second charging means.
Claim 13
Dependent Claim
14 words
A device according to claim 8 further including means for cleaning said photosensitive element.
Claim 14
Dependent Claim
14 words
A device according to claim 8 wherein said photosensitive element has a cylindrical shape.
Claim 15
Dependent Claim
19 words
A device according to claim 8 wherein said photosensitive element includes a photosensitive film disposed over a conductive layer.
Claim 16
Dependent Claim
19 words
A device according to claim 13 wherein said photosensitive element is amorphous selenium and said conductive layer is aluminum.
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) | 1993-03-19 | 1993-09-18 | 1994-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-19 | 1997-09-18 | 1998-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-19 | 2001-09-18 | 2002-03-20 | $7700.00 | Window Closed / Lapsed |