Patent US3894797A successfully refreshed from Google Patents.
US3894797A
Expired / Lapsed
US
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Projection unit, particularly for transparencies
Assignee: ENNA WERK OPTIK APELT
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Filing: 1973-09-24
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Granted: 1975-07-15
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Expires: 1993-09-24
Abstract
Abstract A projection unit for side by side or superimposed projection is disclosed wherein two projection devices are rotatably mounted within a housing in side by side relationship. Each projection device has optical system for projecting a picture onto a screen. The optical system in each projection unit is offset towards the adjacent projection unit. The projection units are interconnected by a linkage system which, upon rotation of one projection device, causes the other projection device to move through an equal angle in the opposite direction.
Inventors
- 👤 Karlheinz Barowski
- 👤 Kurt Schubel
- 👤 Hans Welnhofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:14
CPC Classifications
G; G03; G03B; G03B23/00; G03B23/18
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
128 words
A projection unit for side by side or superimposed projection comprising, a. an outer housing, b. at least two projection devices rotatably mounted within said housing, disposed in a side by side relationship, each projection device having optical means for projecting a picture, the axis of each of said optical means being offset from a central axis of its projection device parallel to the optical means axis, in a direction toward the adjacent projection device, and c. means connected to one of said projection devices to rotate said one projection device; and d. means interconnecting said one projection device with said other projection device so as to cause said other projection device to rotate through an equal angle, but in an opposite direction from said one projection device.
Claim 2
Dependent Claim
128 words
A projection unit for side by side or superimposed projection comprising, a. an outer housing, b. at least two projection devices rotatably mounted within said housing, disposed in a side by side relationship, each projection device having optical means for projecting a picture, the axis of each of said optical means being offset from a central axis of its projection device parallel to the optical means axis, in a direction toward the adjacent projection device, and c. means connected to one of said projection devices to rotate said one projection device; and d. means interconnecting said one projection device with said other projection device so as to cause said other projection device to rotate through an equal angle, but in an opposite direction from said one projection device.
Claim 3
Dependent Claim
42 words
The projection unit of claim 1 wherein said means for rotating said one projection device comprises: a. a toothed wheel rotatably attached to said housing, and b. a rack engaging said Toothed wheel and attached to said one of said projecting devices.
References Cited (Backward Citations)
US3373654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |