US3883349A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic charging method
Assignee: Xerox Ltd
•
Filing: 1973-02-22
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Granted: 1975-05-13
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Expires: 1993-02-22
Abstract
Abstract A method of charging an electrophotographic surface which comprises charging a boundary portion of the surface with a greater electrostatic charge than that portion of the surface which is to be exposed and developed to form an image. The high boundary charge minimizes or eliminates the deposition of toner in image highlight and background areas in the image portion of the electrophotographic surface.
Inventors
- 👤 Masamichi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:55
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/02; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
75 words
IN AN ELECTROPHOTOGRAPHIC METHOD OF FORMING AN IMAGE SUBSTANTIALLY FREE OF BACKGROUND AND HIGHLIGHT FOG, WHEREIN AN ELECTROSTATIC CHARGE IS APPLIED TO A PHOTORECEPTOR SURFACE, AN IMAGE AREA OF SAID CHARGED SURFACE IS EXPOSED TO A LIGHT IMAGE TO FORM A LATENT ELECTROSTATIC IMAGE, AND SAID EXPOSED SURFACE IS THEN DEVELOPED, THE IMPROVEMENT WHICH COMPRISES CHARGING A PORTION OF SAID SURFACE OUTSIDE OF SAID IMAGE AREA WITH AN ELECTROSTATIC CHARGE GREATER THAN THE FIRST-MENTIONED CHARGE,
Claim 2
Dependent Claim
75 words
IN AN ELECTROPHOTOGRAPHIC METHOD OF FORMING AN IMAGE SUBSTANTIALLY FREE OF BACKGROUND AND HIGHLIGHT FOG, WHEREIN AN ELECTROSTATIC CHARGE IS APPLIED TO A PHOTORECEPTOR SURFACE, AN IMAGE AREA OF SAID CHARGED SURFACE IS EXPOSED TO A LIGHT IMAGE TO FORM A LATENT ELECTROSTATIC IMAGE, AND SAID EXPOSED SURFACE IS THEN DEVELOPED, THE IMPROVEMENT WHICH COMPRISES CHARGING A PORTION OF SAID SURFACE OUTSIDE OF SAID IMAGE AREA WITH AN ELECTROSTATIC CHARGE GREATER THAN THE FIRST-MENTIONED CHARGE,
Claim 3
Dependent Claim
23 words
In the method as set forth in claim 1, said portion comprising a border area around the entire periphery of the image area.
Claim 4
Dependent Claim
25 words
In the method as set forth in claim 1, said portion comprising at least a pair of opposite edge border areas of said image area.
Claim 5
Dependent Claim
32 words
In the method as set forth in claim 1, said portion of said surface is first charged with said second-mentioned charge, and then the entire surface is exposed to said first-mentioned charge.
Claim 6
Dependent Claim
29 words
In the method as set forth in claim 4, the image area of said surface is shielded while said portion of said surface is charged with said second-mentioned charge.
Claim 7
Dependent Claim
31 words
In the method as set forth in claim 1, the first-mentioned charge is first applied to said surface and then said second-mentioned charge is applied to said portion of said surface.
Claim 8
Dependent Claim
29 words
In the method as set forth in claim 6, the image area of said surface is shielded while said second-mentioned charge is applied to said portion of said surface.
References Cited (Backward Citations)
US3140945A
Cited
US3730709A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |