Patent US3167998A successfully refreshed from Google Patents.
US3167998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable overhead projecting apparatus
Assignee: 3M Co
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Filing: 1961-04-17
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Granted: 1965-02-02
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Expires: 1981-04-17
Abstract
No abstract record available.
Inventors
- 👤 Roger H Appeldorn
- 👤 Frank C Lustig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:19
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/132; Y; Y10; Y10S; Y10S353/00; Y10S353/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
198 words
A PORTABLE OVERHEAD PROJECTOR COMPRISING A BOX-LIKE CASE HAVING A TOP WALL FORMED WITH AN OPENING ADJACENT ONE END EXTENDING ACROSS THE MAJOR PORTION OF THE WIDTH THEREOF AND HAVING AN AREA GREATER THAN HALF THE AREA OF SAID TOP WALL, A TRANSPARENCY STAGE CO-EXTENSIVE WITH SAID OPENING, A FLAT MIRROR WITHIN SAID CASE EXTENDING FROM ADJACENT SAID ONE END OF SAID TOP WALL DOWNWARDLY UNDER SAID STAGE AT AN ANGLE OF LESS THAN 45 DEGREES FROM THE PLANE OF SAID TOP WALL, A PROJECTION LAMP MOUNTED WITHIN SAID CASE ADJACENT THE OPPOSITE END OF SAID TOP WALL IN POSITION TO DIRECT LIGHT RAYS AT SAID MIRROR AT AN ANGLE OF INCIDENCE LESS THAN 45 DEGREES, A YOKE MOVABLY MOUNTED ON SAID CASE AND HAVING AN OPERATIVE POSITION INCLINED ABOVE SAID STAGE, SAID YOKE ALSO HAVING A SECOND POSITION IN SUBSTANTIAL PARALLELISM WITH SAID TOP WALL, AND A PROJECTION LENS ASSEMBLY CARRIED BY SAID YOKE IN OPERATIVE POSITION ABOVE SAID STAGE WHEN SAID YOKE IS IN OPERATIVE POSITION TION, SAID LENS ASSEMBLY WHEN IN SAID OPERATIVE POSITION BEING DISPOSED TO RECEIVE LIGHT FROM SAID LAMP REFLECTED THROUGH SAID STAGE BY SAID MIRROR FOR PROJECTION TOWARD A REMOTE SCREEN.
Claim 2
Dependent Claim
198 words
A PORTABLE OVERHEAD PROJECTOR COMPRISING A BOX-LIKE CASE HAVING A TOP WALL FORMED WITH AN OPENING ADJACENT ONE END EXTENDING ACROSS THE MAJOR PORTION OF THE WIDTH THEREOF AND HAVING AN AREA GREATER THAN HALF THE AREA OF SAID TOP WALL, A TRANSPARENCY STAGE CO-EXTENSIVE WITH SAID OPENING, A FLAT MIRROR WITHIN SAID CASE EXTENDING FROM ADJACENT SAID ONE END OF SAID TOP WALL DOWNWARDLY UNDER SAID STAGE AT AN ANGLE OF LESS THAN 45 DEGREES FROM THE PLANE OF SAID TOP WALL, A PROJECTION LAMP MOUNTED WITHIN SAID CASE ADJACENT THE OPPOSITE END OF SAID TOP WALL IN POSITION TO DIRECT LIGHT RAYS AT SAID MIRROR AT AN ANGLE OF INCIDENCE LESS THAN 45 DEGREES, A YOKE MOVABLY MOUNTED ON SAID CASE AND HAVING AN OPERATIVE POSITION INCLINED ABOVE SAID STAGE, SAID YOKE ALSO HAVING A SECOND POSITION IN SUBSTANTIAL PARALLELISM WITH SAID TOP WALL, AND A PROJECTION LENS ASSEMBLY CARRIED BY SAID YOKE IN OPERATIVE POSITION ABOVE SAID STAGE WHEN SAID YOKE IS IN OPERATIVE POSITION TION, SAID LENS ASSEMBLY WHEN IN SAID OPERATIVE POSITION BEING DISPOSED TO RECEIVE LIGHT FROM SAID LAMP REFLECTED THROUGH SAID STAGE BY SAID MIRROR FOR PROJECTION TOWARD A REMOTE SCREEN.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-02-02 | 1968-08-03 | 1969-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-02-02 | 1972-08-03 | 1973-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-02-02 | 1976-08-03 | 1977-02-02 | $7700.00 | Window Closed / Lapsed |