US2990280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic printing
Assignee: RCA Corp
•
Filing: 1958-10-24
•
Granted: 1961-06-27
•
Expires: 1978-10-24
Abstract
No abstract record available.
Inventors
- 👤 Jr Edward C Giaimo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:07
CPC Classifications
G; G03; G03G; G03G11/00; G03G13/00; G03G13/22; G03G9/00; G03G9/08; G03G9/10; G03G9/103; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
161 words
A METHOD OF PRODUCING A VISIBLE POWDER IMAGE ON A DARK ADAPTED UNCHARGED ELECTROPHOTOGRAPHIC ELEMENT COMPRISING A SUBSTATE HAVINA A COATING THEREON AND IN INTIMATE CONTACT THEREWITH OF A FINELY-DIVIDED PHOTOCONDUCTOR DISPERSED IN AN ELECTRICALLY INSULATING VEHICLE, SAID METHOD COMPRISING THE STEPS OF: MAINTAINING SAID ELEMENT IN DARKNESS AND, WITHOUT APPLYING ANY ELECTRIC FIELD TO SAID ELEMENT, EXPOSING SAID COATING TO A LIGHT IMAGE TO PRODUCE THEREIN A LATENT CONDUCTIVITY PATTERN IN SUBSTANTIAL CONFIGURATION WITH SAID LIGHT IMAGE, THEN, IN THE ABSENCE OF ANY ELECTRIC FIELD EXTERNALLY APPLIED THROUGH SAID ELEMENT, CONTACTING A SURFACE OF SAID ELEMENT WITH A MIXTURE OF A CARRIER MATERIAL AND DEVELOPER POWDER PARTICLES SEPARATED FROM SAID CARRIER MATERIAL IN THE TRIBOELECTRIC SERIES, SAID DEVELOPER POWDER PARTICLES BEING ATTRACTED TO SAID SURFACE SOLELY AS THE RESULT OF THE TRIBOELECTRIC RELATIONSHIP EXISTING BETWEEN SAID CARRIER MATERIAL AND SAID DEVELOPER POWDER PARTICLES IN SAID MIXTURE AND THE TRIBOELECTRIC CHARGES GENERATED DURING THE CONTACTING OF SAID MIXTURE WITH SAID SURFACE.
Claim 2
Independent Claim
161 words
A METHOD OF PRODUCING A VISIBLE POWDER IMAGE ON A DARK ADAPTED UNCHARGED ELECTROPHOTOGRAPHIC ELEMENT COMPRISING A SUBSTATE HAVINA A COATING THEREON AND IN INTIMATE CONTACT THEREWITH OF A FINELY-DIVIDED PHOTOCONDUCTOR DISPERSED IN AN ELECTRICALLY INSULATING VEHICLE, SAID METHOD COMPRISING THE STEPS OF: MAINTAINING SAID ELEMENT IN DARKNESS AND, WITHOUT APPLYING ANY ELECTRIC FIELD TO SAID ELEMENT, EXPOSING SAID COATING TO A LIGHT IMAGE TO PRODUCE THEREIN A LATENT CONDUCTIVITY PATTERN IN SUBSTANTIAL CONFIGURATION WITH SAID LIGHT IMAGE, THEN, IN THE ABSENCE OF ANY ELECTRIC FIELD EXTERNALLY APPLIED THROUGH SAID ELEMENT, CONTACTING A SURFACE OF SAID ELEMENT WITH A MIXTURE OF A CARRIER MATERIAL AND DEVELOPER POWDER PARTICLES SEPARATED FROM SAID CARRIER MATERIAL IN THE TRIBOELECTRIC SERIES, SAID DEVELOPER POWDER PARTICLES BEING ATTRACTED TO SAID SURFACE SOLELY AS THE RESULT OF THE TRIBOELECTRIC RELATIONSHIP EXISTING BETWEEN SAID CARRIER MATERIAL AND SAID DEVELOPER POWDER PARTICLES IN SAID MIXTURE AND THE TRIBOELECTRIC CHARGES GENERATED DURING THE CONTACTING OF SAID MIXTURE WITH SAID SURFACE.
References Cited (Backward Citations)
US2297691A
Cited
US2808328A
Cited
US2845348A
Cited
US2874063A
Cited
US2853383A
Cited
US2839400A
Cited
US2803177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-26 | 1964-12-26 | 1965-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-26 | 1968-12-26 | 1969-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-26 | 1972-12-26 | 1973-06-27 | $7700.00 | Window Closed / Lapsed |