Patent US4396273A successfully refreshed from Google Patents.
Patent US3762811A successfully refreshed from Google Patents.
US3762811A
Expired / Lapsed
US
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Method and apparatus for electrophotography
Assignee: Fujifilm Holdings Corp
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Filing: 1971-07-23
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Granted: 1973-10-02
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Expires: 1991-07-23
Abstract
Abstract In an electrophotographic method in which an electrophotostatic latent image is obtained by uniformly charging and imagewise exposing an electrophotosensitive material and letting toner stick to the material according to the electrostatic latent image thereon, the electrophotographic method characterized in that the uniform charge on the electrophotosensitive material is varied according to the desirable contrast of the image to be obtained, and the exposure is controlled according to the surface potential, thereby obtaining a controlled contrast.
Inventors
- 👤 S Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:49
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/043; G03G15/02; G03G15/0266; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
88 words
In an electrophotographic apparatus to obtain a visible toner image by uniformly charging, imagewise exposing an electrophotosensitive material and then applying toner, apparatus comprising a discharge means for uniformly charging the electrophotographic material including means for controlling the potential of the surface charge on the elctrophotosensitive material, and an image exposing means which controls, in response fo the operation of said surface potential controlling means and prior to said imagewise exposing, the amount of exposure to be used during said imagewise exposing in relation to the surface potential.
Claim 2
Dependent Claim
88 words
In an electrophotographic apparatus to obtain a visible toner image by uniformly charging, imagewise exposing an electrophotosensitive material and then applying toner, apparatus comprising a discharge means for uniformly charging the electrophotographic material including means for controlling the potential of the surface charge on the elctrophotosensitive material, and an image exposing means which controls, in response fo the operation of said surface potential controlling means and prior to said imagewise exposing, the amount of exposure to be used during said imagewise exposing in relation to the surface potential.
Claim 3
Dependent Claim
26 words
An electrophotographic apparatus as claimed in claim 2, wherein said discharge means has a circuit for varying the voltage to be applied to a discharging electrode.
Claim 4
Dependent Claim
30 words
An electrophotographic apparatus as claimed in claim 1, wherein said discharge means has a mechanism for varying the distance between a discharging electrode and the surface of the electrophotographic material.
Claim 5
Dependent Claim
21 words
An electrophotographic apparatus as claimed in claim 1, wherein said image exposing means has a timer for varying the exposure time.
Claim 6
Dependent Claim
23 words
An electrophotographic apparatus as claimed in claim 1, wherein said image exposing means has a circuit for varying the intensity of exposing lamp.
Claim 7
Dependent Claim
30 words
An electrophotographic apparatus as claimed in claim 1, wherein said image exposing means has a mechanism for controlling the transfer speed of the electrophotographic material through the image exposing station.
Claim 8
Dependent Claim
32 words
An electrophotographic apparatus as claimed in claim 1, wherein said image exposing means has an iris in the image exposing optical path, the opening of which is controlled by the surface potential.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |