Patent US3840291A successfully refreshed from Google Patents.
US3840291A
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US
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Pancratic magnification changer
Assignee: Carl Zeiss AG
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Filing: 1972-10-31
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Granted: 1974-10-08
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Expires: 1992-10-31
Abstract
Abstract A pancratic magnification changer, particularly for operation and routine microscopes in which the actuating members for the magnification changer are so controlled that the speed of change of the magnification is a desired nonlinear function of the magnification.
Inventors
- 👤 H Littmann
- 👤 W Pfeiffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:11
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/02; G02B21/025
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
101 words
A pancratic magnification changer comprising a supporting framework, optical means in said framework, actuating means operatively connected with said optical means for altering the inter-relation of the same in said framework to thereby change the magnification, a drive motor for said actuating means and control means acting on said actuating means to cause the rate of change of the magnification to increase in excess of a linear rate with increasing magnification and to decrease at less than a linear rate with decreasing magnification, whereby the observer receives the impression that the magnification is changing with constant speed throughout the magnification range.
Claim 2
Dependent Claim
101 words
A pancratic magnification changer comprising a supporting framework, optical means in said framework, actuating means operatively connected with said optical means for altering the inter-relation of the same in said framework to thereby change the magnification, a drive motor for said actuating means and control means acting on said actuating means to cause the rate of change of the magnification to increase in excess of a linear rate with increasing magnification and to decrease at less than a linear rate with decreasing magnification, whereby the observer receives the impression that the magnification is changing with constant speed throughout the magnification range.
Claim 3
Dependent Claim
47 words
A pancratic magnification changer according to claim 1 in which said actuating means includes a guide cylinder having guide surfaces thereon, means for rotating said drive motor with constant angular velocity, and transmission means having a variable transmission ratio interconnecting said drive motor and said guide cylinder.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |