US3081671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical objectives of variable focal length
Assignee: Rank Precision Industries Ltd
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Filing: 1960-07-14
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Granted: 1963-03-19
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Expires: 1980-07-14
Abstract
No abstract record available.
Inventors
- 👤 Cook Gordon Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:01
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/143; G02B15/1431; G02B15/143105
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
229 words
A VARIABLE FOCAL LENGTH OPTICAL OBJECTIVE, COMPRISING FRONT AND REAR ASSEMBLIES, THE FRONT ASSEMBLY INCLUDING MEMBERS RELATIVELY MOVABLE FOR EFFECTING VARIATION OF THE EQUIVALENT FOCAL LENGTH OF THE OBJECTIVE WHILST MAINTAINING CONSTANT POSITION OF THE RESULTANT IMAGE PLANE OF THE OBJECTIVE THROUGHOUT THE RANGE OF RELATIVE MOVEMENT, AND THE REAR ASSEMBLY INCLUDING A STATIONARY FRONT MEMBER, A CONVERGENT STATIONARY REAR MEMBER, AN ADJUSTABLE DIVERGENT MEMBER LOCATED BETWEEN SUCH FRONT AND REAR MEMBERS, AND MEANS FOR AXIALLY ADJUSTING SUCH DIVERGENT MEMBER FROM ONE TO THE OTHER OF TWO PRESET POSITIONS IN WHICH SUCH DIVERGENT MEMBER HAS THE SAME CONJUGATES, WHEREBY IN SUCH TWO PRESET POSITIONS OF THE DIVERGENT MEMBER THE RELATIVE MOVEMENT OF THE MEMBERS OF THE FRONT ASSEMBLY WILL PRODUCE TWO DIFFERENT RANGES OF VARIATION OF THE EQUIVALENT FOCAL LENGTH OF THE COMPLETE OBJECTIVE WITH THE SAME POSITION OF THE RESULTANT IMAGE PLANE, THE MAGNIFICATIONS OF THE DIVERGENT MEMBER OF THE REAR ASSEMBLY IN ITS TWO PRESET POSITIONS RESPECTIVELY BEING $M AND 1/$M, WHERE M IS THE RATIO BETWEEN THE TWO VALUES OF THE EQUIVALENT FOCAL LENGTH OF THE OBJECTIVE RESPECTIVELY WHEN THE DIVERGENT MEMBER OF THE REAR ASSEMBLY IS OCCUPYING ITS TWO PRESET POSITIONS WITHOUT CHANGE OF POSITION OF THE MOVABLE MEMBERS OF THE FRONT ASSEMBLY, THE STATIONARY FRONT MEMBER OF THE REAR ASSEMBLY HAVING EQUIVALENT POWER LYING BETWEEN 2/3 AND 3/2 TIMES THE VALUE OF THE EXPRESSION
Claim 2
Dependent Claim
229 words
A VARIABLE FOCAL LENGTH OPTICAL OBJECTIVE, COMPRISING FRONT AND REAR ASSEMBLIES, THE FRONT ASSEMBLY INCLUDING MEMBERS RELATIVELY MOVABLE FOR EFFECTING VARIATION OF THE EQUIVALENT FOCAL LENGTH OF THE OBJECTIVE WHILST MAINTAINING CONSTANT POSITION OF THE RESULTANT IMAGE PLANE OF THE OBJECTIVE THROUGHOUT THE RANGE OF RELATIVE MOVEMENT, AND THE REAR ASSEMBLY INCLUDING A STATIONARY FRONT MEMBER, A CONVERGENT STATIONARY REAR MEMBER, AN ADJUSTABLE DIVERGENT MEMBER LOCATED BETWEEN SUCH FRONT AND REAR MEMBERS, AND MEANS FOR AXIALLY ADJUSTING SUCH DIVERGENT MEMBER FROM ONE TO THE OTHER OF TWO PRESET POSITIONS IN WHICH SUCH DIVERGENT MEMBER HAS THE SAME CONJUGATES, WHEREBY IN SUCH TWO PRESET POSITIONS OF THE DIVERGENT MEMBER THE RELATIVE MOVEMENT OF THE MEMBERS OF THE FRONT ASSEMBLY WILL PRODUCE TWO DIFFERENT RANGES OF VARIATION OF THE EQUIVALENT FOCAL LENGTH OF THE COMPLETE OBJECTIVE WITH THE SAME POSITION OF THE RESULTANT IMAGE PLANE, THE MAGNIFICATIONS OF THE DIVERGENT MEMBER OF THE REAR ASSEMBLY IN ITS TWO PRESET POSITIONS RESPECTIVELY BEING $M AND 1/$M, WHERE M IS THE RATIO BETWEEN THE TWO VALUES OF THE EQUIVALENT FOCAL LENGTH OF THE OBJECTIVE RESPECTIVELY WHEN THE DIVERGENT MEMBER OF THE REAR ASSEMBLY IS OCCUPYING ITS TWO PRESET POSITIONS WITHOUT CHANGE OF POSITION OF THE MOVABLE MEMBERS OF THE FRONT ASSEMBLY, THE STATIONARY FRONT MEMBER OF THE REAR ASSEMBLY HAVING EQUIVALENT POWER LYING BETWEEN 2/3 AND 3/2 TIMES THE VALUE OF THE EXPRESSION
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) | 1966-03-18 | 1966-09-17 | 1967-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-03-18 | 1970-09-17 | 1971-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-03-18 | 1974-09-17 | 1975-03-19 | $7700.00 | Window Closed / Lapsed |