Patent US4275321A successfully refreshed from Google Patents.
US3345294A
Expired / Lapsed
US
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Developer mix for electrostatic printing
Assignee: American Photocopy Equipment Co
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Filing: 1964-04-28
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Granted: 1967-10-03
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Expires: 1984-04-28
Abstract
No abstract record available.
Inventors
- 👤 Robert N Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:59
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; G03G9/00; G03G9/08; G03G9/083; G03G9/087; G03G9/08742; G03G9/08755
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
A DEVELOPER MIX FOR USE IN ELECTROSTATIC PRINTING TO DEVELOP LATENT IMAGES, INCLUDING CHARGED AND UNCHARGED AREAS OF AN IMAGE-BEARING SHEET, SAID DEVELOPER MIX COMPRISING THE COMBINATION OF SEPARATE GRANULAR MAGNETICALLY ATTRACTABLE CARRIER PARTICLES AND A DEVELOPER POWDER COMPRISING A COLORING AGENT AND A RESIN HAVING A TRIBOELECTRIC RELATIONSHIP OF OPPOSITE POLARITY WITH RESPECT TO SAID MAGNETICALLY ATTRACTABLE GRANULES, AT LEAST A MAJOR PORTION OF SAID RESIN BEING COMPOSED OF A POLYAMIDE RESIN HAVING A SHARP MELTING POINT WITHIN THE RANGE OF ABOUT 70*C. TO ABOUT 165*C. WHEREBY DEVELOPED IMAGES OF SUBSTANTIALLY IMPROVED BLACK DENSITY MAY BE FORMED OVER EXTENDED OPERATING PERIODS.
Claim 2
Dependent Claim
102 words
A DEVELOPER MIX FOR USE IN ELECTROSTATIC PRINTING TO DEVELOP LATENT IMAGES, INCLUDING CHARGED AND UNCHARGED AREAS OF AN IMAGE-BEARING SHEET, SAID DEVELOPER MIX COMPRISING THE COMBINATION OF SEPARATE GRANULAR MAGNETICALLY ATTRACTABLE CARRIER PARTICLES AND A DEVELOPER POWDER COMPRISING A COLORING AGENT AND A RESIN HAVING A TRIBOELECTRIC RELATIONSHIP OF OPPOSITE POLARITY WITH RESPECT TO SAID MAGNETICALLY ATTRACTABLE GRANULES, AT LEAST A MAJOR PORTION OF SAID RESIN BEING COMPOSED OF A POLYAMIDE RESIN HAVING A SHARP MELTING POINT WITHIN THE RANGE OF ABOUT 70*C. TO ABOUT 165*C. WHEREBY DEVELOPED IMAGES OF SUBSTANTIALLY IMPROVED BLACK DENSITY MAY BE FORMED OVER EXTENDED OPERATING PERIODS.
References Cited (Backward Citations)
US2940934A
Cited
US3117884A
Cited
US2899335A
Cited
US3041169A
Cited
US3093039A
Cited
US3060051A
Cited
US3185777A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-10-02 | 1971-04-03 | 1971-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-10-02 | 1975-04-03 | 1975-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-10-02 | 1979-04-03 | 1979-10-03 | $7700.00 | Window Closed / Lapsed |