Patent US2743320A successfully refreshed from Google Patents.
Patent US3251685A successfully refreshed from Google Patents.
US3251685A
Expired / Lapsed
US
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Method of controlling contrast in a xerographic reproduction process
Assignee: Xerox Corp
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Filing: 1959-10-19
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Granted: 1966-05-17
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Expires: 1979-10-19
Abstract
No abstract record available.
Inventors
- 👤 John T Bickmore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/04; G03G15/043; G03G15/065; G03G15/22; G03G15/26; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
193 words
THE METHOD OF CONTROLLING CONTRAST IN A XEROGRAPHIC REPRODUCTION PROCESS WHEREIN A XEROGRAPHIC PLATE IS CHARGED, EXPOSED TO A PATTERN OF LIGHT AND SHADOW TO PRODUCE A LATENT CHARGE PATTERN AND DEVELOPED IN PROPORTION TO THE AMOUNT BY WHICH THE LOCAL POTENTIAL V OF THE ELECTROSTATIC CHARGE PATTERN IS LESS STHAN A FIXED BIAS POTENTIAL ON A DEVELOPMENT ELECTRODE, SAID METHOD COMPRISING APPLYING A CHARGING POTENTIAL VO, GREATER THAN SAID FIXED BIAS POTENTIAL, AND EXPOSING THE PLATE TO A PATTERN OF LIGHT AND SHADOW UNTIL SUBSTANTIALLY ALL AREAS THEREOF ARE REDUCED TO A POTENTIAL BELOW SAID FIXED IAS POTENTIAL WHEREBY THE SAID LOCAL POTENTIAL V REMAINING AT ANY GIVEN POINT ON THE PLATE, AFTER SAID EXPOSURE IS GEOVERNED BY THE EXPRESSION $-$=KE WHERE E IS THE SAID EXPOSURE AT THE SAID GIVEN POINT AND K IS A CONSTANT WHICH IS A FUNCTION OF SAID PLATE, SAID VO BEING CHOSEN SO THAT THE SAID REMAINING LOCAL POTENTIAL V WILL VARY FROM POINT TO POINT WITHIN A RANGE OF VALUES CORRESPONDING TO A DESIRED CONTRAST RANGE IN THE DEVELOPED PLATE, AND POSITIONING SAID DEVELOPMENT ELECTRODE ADJACENT TO THE DEVELOPABLE SURFACE OF SAID PLATE FOR DEVELOPMENT.
Claim 2
Independent Claim
193 words
THE METHOD OF CONTROLLING CONTRAST IN A XEROGRAPHIC REPRODUCTION PROCESS WHEREIN A XEROGRAPHIC PLATE IS CHARGED, EXPOSED TO A PATTERN OF LIGHT AND SHADOW TO PRODUCE A LATENT CHARGE PATTERN AND DEVELOPED IN PROPORTION TO THE AMOUNT BY WHICH THE LOCAL POTENTIAL V OF THE ELECTROSTATIC CHARGE PATTERN IS LESS STHAN A FIXED BIAS POTENTIAL ON A DEVELOPMENT ELECTRODE, SAID METHOD COMPRISING APPLYING A CHARGING POTENTIAL VO, GREATER THAN SAID FIXED BIAS POTENTIAL, AND EXPOSING THE PLATE TO A PATTERN OF LIGHT AND SHADOW UNTIL SUBSTANTIALLY ALL AREAS THEREOF ARE REDUCED TO A POTENTIAL BELOW SAID FIXED IAS POTENTIAL WHEREBY THE SAID LOCAL POTENTIAL V REMAINING AT ANY GIVEN POINT ON THE PLATE, AFTER SAID EXPOSURE IS GEOVERNED BY THE EXPRESSION $-$=KE WHERE E IS THE SAID EXPOSURE AT THE SAID GIVEN POINT AND K IS A CONSTANT WHICH IS A FUNCTION OF SAID PLATE, SAID VO BEING CHOSEN SO THAT THE SAID REMAINING LOCAL POTENTIAL V WILL VARY FROM POINT TO POINT WITHIN A RANGE OF VALUES CORRESPONDING TO A DESIRED CONTRAST RANGE IN THE DEVELOPED PLATE, AND POSITIONING SAID DEVELOPMENT ELECTRODE ADJACENT TO THE DEVELOPABLE SURFACE OF SAID PLATE FOR DEVELOPMENT.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-05-16 | 1969-11-15 | 1970-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-05-16 | 1973-11-15 | 1974-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-05-16 | 1977-11-15 | 1978-05-17 | $7700.00 | Window Closed / Lapsed |