US3249430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing images in electrophotography and radiography
Assignee: Australian Government
•
Filing: 1961-08-02
•
Granted: 1966-05-03
•
Expires: 1981-08-02
Abstract
No abstract record available.
Inventors
- 👤 Kenneth A Metcalfe
- 👤 Robert J Wright
- 👤 Robert V Wissell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:01
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/04; Y; Y10; Y10S; Y10S430/00; Y10S430/167
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
THE METHOD OF CONTROLLING CONTRAST OF A XEROGRAPHIC IMAGE WHICH CONSISTS OF THE STEPS OF FIRST UNIFORMLY PREEXPOSING A PHOTO-CONDUCTOR SURFACE TO HIGH INTENSITY ELECTROMAGNETIC WAVES OF A WAVE LENGTH WHICH CAN BE ABSORBED BY THE PHOTO-CONDUCTOR AND TO WHICH THE SURFACE IS SENSITIVE WHEREBY THE PHOTO-CONDUCTOR IS FATIGUED SO THAT BOTH ITS CHARGE HOLDING ABILITY AND ITS LEAKAGE RATE IS DECREASED, SUBSEQUENTLY CHARGING THE THUS FATIGUED PHOTO-CONDUCTOR IN THE ABSENCE OF LIGHT BY SUBJECTING THE PHOTO-CONDUCTOR TO A CORONA DISCHARGE TO PRODUCE A UNIFORM ELECTRIC CHARGE ON THE PHOTO-CONDUCTOR, THEN EXPOSING THE PHOTO-CONDUCTOR TO ELECTROMAGNETIC WAVES OF THE REQUIRED PATTERN TO DIFFERENTIALLY BLEED AWAY THE CHARGE AND PRODUCE AN ELECTROSTATIC IMAGE, AND THEN DEVELOPING THE ELECTROSTATIC IMAGE BY APPLYING A DEVELOPER WHICH DEPOSITS ACCORDING TO THE ELECTROSTATIC PATTERN.
Claim 2
Independent Claim
129 words
THE METHOD OF CONTROLLING CONTRAST OF A XEROGRAPHIC IMAGE WHICH CONSISTS OF THE STEPS OF FIRST UNIFORMLY PREEXPOSING A PHOTO-CONDUCTOR SURFACE TO HIGH INTENSITY ELECTROMAGNETIC WAVES OF A WAVE LENGTH WHICH CAN BE ABSORBED BY THE PHOTO-CONDUCTOR AND TO WHICH THE SURFACE IS SENSITIVE WHEREBY THE PHOTO-CONDUCTOR IS FATIGUED SO THAT BOTH ITS CHARGE HOLDING ABILITY AND ITS LEAKAGE RATE IS DECREASED, SUBSEQUENTLY CHARGING THE THUS FATIGUED PHOTO-CONDUCTOR IN THE ABSENCE OF LIGHT BY SUBJECTING THE PHOTO-CONDUCTOR TO A CORONA DISCHARGE TO PRODUCE A UNIFORM ELECTRIC CHARGE ON THE PHOTO-CONDUCTOR, THEN EXPOSING THE PHOTO-CONDUCTOR TO ELECTROMAGNETIC WAVES OF THE REQUIRED PATTERN TO DIFFERENTIALLY BLEED AWAY THE CHARGE AND PRODUCE AN ELECTROSTATIC IMAGE, AND THEN DEVELOPING THE ELECTROSTATIC IMAGE BY APPLYING A DEVELOPER WHICH DEPOSITS ACCORDING TO THE ELECTROSTATIC PATTERN.
References Cited (Backward Citations)
US2690394A
Cited
US2845348A
Cited
US2741959A
Cited
US2914403A
Cited
US2907674A
Cited
US3041167A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-05-02 | 1969-11-01 | 1970-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-05-02 | 1973-11-01 | 1974-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-05-02 | 1977-11-01 | 1978-05-03 | $7700.00 | Window Closed / Lapsed |