US4942415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter for a photogrammetric camera
Assignee: Carl Zeiss AG
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Filing: 1989-08-30
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Granted: 1990-07-17
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Expires: 2009-08-30
Abstract
Abstract The invention is directed to a shutter wherein the rotary discs thereof are accelerated out of a standstill start position for each exposure operation and are again brought to standstill at the end of the exposure operation. The start position is computed such that a constant access time results for all exposure times. An electronic control circuit for the shutter includes a position-control circuit and a speed-control circuit. During each exposure operation, the drive for the rotary discs of the shutter are switched between the two control loops.
Inventors
- 👤 Karl Felle
- 👤 Heinz Krastel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:27
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/10; G03B9/18; G03B9/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A shutter for a photogrammetric camera comprising: rotatably mounted disc means for defining a shutter opening; drive means for rotatably driving said disc means for each exposure operation by accelerating said disc means out of a standstill start position thereof; angle encoder means for measuring said start position of said disc means; a control circuit for providing a signal indicative of a desired exposure time t B ; and, a device operatively connected to said drive means for displacing said start position of said disc means in dependence upon said signal so as to cause the access time t z between the start t o of the acceleration and the exposure for different adjustable exposure times (t B1 , t B2 ) to have a substantially constant value.
Claim 2
Dependent Claim
128 words
A shutter for a photogrammetric camera comprising: rotatably mounted disc means for defining a shutter opening; drive means for rotatably driving said disc means for each exposure operation by accelerating said disc means out of a standstill start position thereof; angle encoder means for measuring said start position of said disc means; a control circuit for providing a signal indicative of a desired exposure time t B ; and, a device operatively connected to said drive means for displacing said start position of said disc means in dependence upon said signal so as to cause the access time t z between the start t o of the acceleration and the exposure for different adjustable exposure times (t B1 , t B2 ) to have a substantially constant value.
Claim 3
Dependent Claim
34 words
The shutter of claim 1, said disc means comprising a plurality of rotatably mounted discs; and, transmission means for interconnecting said discs to each other and to said drive means at different speed ratios.
Claim 4
Dependent Claim
12 words
The shutter of claim 2, said transmission means being a gear transmission.
Claim 5
Dependent Claim
35 words
The shutter of claim 1, said disc means comprising a plurality of pairs of discs; and, transmission means for interconnecting said disc pairs to each other and to said drive means at different speed ratios.
Claim 6
Dependent Claim
12 words
The shutter of claim 4, said transmission means being a gear transmission.
Claim 7
Dependent Claim
79 words
The shutter of claim 1, further comprising a control arrangement including a position-control loop and a speed-control loop; and, said device including computer means for computing a preselected desired position value U pos and a preselected desired speed value U v in correspondence to the desired exposure time t B and the constant access time t z and for applying said position value U pos to said position-control loop and said speed value U v to said speed-control loop.
Claim 8
Dependent Claim
26 words
The shutter of claim 6, said control arrangement comprising changeover switching means for switching between said position-control loop and said speed-control loop during each exposure operation.
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) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |