US3672748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Split dagor-type of symmetrical copying lens system
Assignee: Xerox Corp
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Filing: 1971-05-14
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Granted: 1972-06-27
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Expires: 1991-05-14
Abstract
Abstract A SPLIT DAGOR-TYPE OF SYMMETRTICAL COPYING LENS SYSTEM HAVING FRONT AND BACK COMPOUND LENS COMPONENTS WITH A CENTRALLY-LOCATED DIAPHRAGM THEREBETWEEN ADAPTED TO AN OPTICAL SYSTEM OF A COPIER WHICH CAN BE USED AT 1:1 MAGNIFICATION. THE FRONT LENS COMPONENT HAS THREE LENS ELEMENTS INCLUDING, IN THE FOLLOWING ORDER, A FIRST LENS ELEMENT OF POSITIVE POWER, A SECOND LENS ELEMENT OF NEGATIVE POWER CEMENTED TO THE FIRST LENS ELEMENT AND A THIRD LENS ELEMENT OF POSITIVE POWER DISPOSED BETWEEN THE SECOND LENS ELEMENT AND DIAPHRAGM, AND THE BACK LENS COMPONENT HAVING THREE SIMILAR LENS ELEMENTS POSITIONED SO THAT THE LENS SYSTEM IS SYMMETRICAL.
Inventors
- 👤 Yoshikazu Doi
- 👤 Yasuo Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:44
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/34; G02B13/00; G02B13/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |