Patent US4547040A successfully refreshed from Google Patents.
US3100239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical focus and resolution testing methods and apparatus
Assignee: AT&T Inc
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Filing: 1960-12-29
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Granted: 1963-08-06
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Expires: 1980-12-29
Abstract
No abstract record available.
Inventors
- 👤 Jeofry S Courtney-Pratt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:47
CPC Classifications
G; G01; G01M; G01M11/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
162 words
THE METHOD OF TESTING THE FOCUS AND RESOLUTION OF AN OPTICAL SYSTEM WHICH COMPRISES, SUPPORTING THE OPTICAL SYSTEM ON A COMMON CENTRAL AXIS WITH A PLANE TEST PATTERN AND A PLANE PHOTOGRAPHIC PLATE, THE TEST PATTERN AND PLATE BEING SITUATED SUBSTANTIALLY IN CONJUGATE PLANES ON OPPOSITE SIDES OF THE OPTICAL SYSTEM, INTERPOSING BETWEEN THE PLATE AND THE OPTICAL SYSTEM AND CLOSELY ADJACENT TO THE PLATE A MASK OF A MATERIAL FREELY TRANSMITTING SUBSTANTIALLY THE FULL FREQUENCY SPECTRUM OF VISIBLE LIGHT AND HAVING A GREATER REFRACTIVE INDEX THAN THAT OF THE SURROUNDING MEDIUM, THE MASK COMPRISING A PLURALITY OF SECTORS OF PROGRESSIVELY INCREASING THICKNESS, ILLUMINATING THE TEST PATTERN AND EXPOSING THE PLATE TO THE IMAGE OF THE TEST PATTERN FORMED BY THE OPTICAL SYSTEM WHEREBY COMPARISON OF THE SECTORS OF THE IMAGE CORRESPONDING TO THE SECTORS OF THE MASK PROVIDES AN INDICATION OF THE ACTUAL DISTANCE FROM OPTICAL SYSTEM TO PLATE AT WHICH THE FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM ARE OPTIMUM.
Claim 2
Independent Claim
162 words
THE METHOD OF TESTING THE FOCUS AND RESOLUTION OF AN OPTICAL SYSTEM WHICH COMPRISES, SUPPORTING THE OPTICAL SYSTEM ON A COMMON CENTRAL AXIS WITH A PLANE TEST PATTERN AND A PLANE PHOTOGRAPHIC PLATE, THE TEST PATTERN AND PLATE BEING SITUATED SUBSTANTIALLY IN CONJUGATE PLANES ON OPPOSITE SIDES OF THE OPTICAL SYSTEM, INTERPOSING BETWEEN THE PLATE AND THE OPTICAL SYSTEM AND CLOSELY ADJACENT TO THE PLATE A MASK OF A MATERIAL FREELY TRANSMITTING SUBSTANTIALLY THE FULL FREQUENCY SPECTRUM OF VISIBLE LIGHT AND HAVING A GREATER REFRACTIVE INDEX THAN THAT OF THE SURROUNDING MEDIUM, THE MASK COMPRISING A PLURALITY OF SECTORS OF PROGRESSIVELY INCREASING THICKNESS, ILLUMINATING THE TEST PATTERN AND EXPOSING THE PLATE TO THE IMAGE OF THE TEST PATTERN FORMED BY THE OPTICAL SYSTEM WHEREBY COMPARISON OF THE SECTORS OF THE IMAGE CORRESPONDING TO THE SECTORS OF THE MASK PROVIDES AN INDICATION OF THE ACTUAL DISTANCE FROM OPTICAL SYSTEM TO PLATE AT WHICH THE FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM ARE OPTIMUM.
Claim 3
Dependent Claim
236 words
APPARATUS FOR TESTING THE FOCUS AND RESOLUTION OF AN OPTICAL SYSTEM COMPRISING MEANS FOR SUPPORTING THE OPTICAL SYSTEM TO BE TESTED, MEANS FOR SUPPORTING A PLANE TEST PATTERN AT AN APPROPRIATE DISTANCE ON ONE SIDE OF THE OPTICAL SYSTEM AND NORMAL TO THE CENTRAL AXIS OF THE SYSTEM, MEANS FOR ILLUMINATING THE TEST PATTERN, MEANS FOR SUPPORTING A PHOTOGRAPHIC PLATE ON THE OTHER SIDE OF THE OPTICAL SYSTEM SUBSTANTIALLY AT THE CONJUGATE PLANE WITH RESPECT TO THE OPTICAL SYSTEM TO FOCUS AN IMAGE OF THE TEST PATTERN ON THE PLATE, MEANS FOR NORMALLY EXCLUDING LIGHT FROM THE PLATE, A MASK OF MATERIAL FREELY TRANSMITTING SUBSTANTIALLY THE FULL FREQUENCY SPECTRUM OF VISIBLE LIGHT AND HAVING A REFRACTIVE INDEX GREATER THAN THAT OF THE SURROUNDING MEDIUM, THE MASK HAVING A PLURALITY OF SECTIONS DIFFERING PROGRESSIVELY IN THICKNESS BY DISCRETE STEPS, THE MASK BEING PLACED BETWEEN THE OPTICAL SYSTEM AND THE PLATE AND CLOSELY ADJACENT TO THE PLATE, AND SHUTTER MEANS ADAPTED TO APPROPRIATELY EXPOSE THE PLATE TO THE IMAGE OF THE TEST PATTERN PRODUCED BY THE OPTICAL SYSTEM, WHEREBY AN IMAGE IS OBTAINED ON THE PHOTOGRAPHIC PLATE HAVING A PLURALITY OF SECTIONS REPRESENTING THE FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM FOR A LIKE PLURALITY OF SLIGHTLY DIFFERING EFFECTIVE DISTANCES BETWEEN THE OPTICAL SYSTEM AND THE PHOTOGRAPHIC PLATE, RESPECTIVELY, FROM WHICH THE OPTIMUM DISTANCE FOR THE CLEAREST ACTUAL FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM CAN BE DEDUCED.
Claim 4
Dependent Claim
236 words
APPARATUS FOR TESTING THE FOCUS AND RESOLUTION OF AN OPTICAL SYSTEM COMPRISING MEANS FOR SUPPORTING THE OPTICAL SYSTEM TO BE TESTED, MEANS FOR SUPPORTING A PLANE TEST PATTERN AT AN APPROPRIATE DISTANCE ON ONE SIDE OF THE OPTICAL SYSTEM AND NORMAL TO THE CENTRAL AXIS OF THE SYSTEM, MEANS FOR ILLUMINATING THE TEST PATTERN, MEANS FOR SUPPORTING A PHOTOGRAPHIC PLATE ON THE OTHER SIDE OF THE OPTICAL SYSTEM SUBSTANTIALLY AT THE CONJUGATE PLANE WITH RESPECT TO THE OPTICAL SYSTEM TO FOCUS AN IMAGE OF THE TEST PATTERN ON THE PLATE, MEANS FOR NORMALLY EXCLUDING LIGHT FROM THE PLATE, A MASK OF MATERIAL FREELY TRANSMITTING SUBSTANTIALLY THE FULL FREQUENCY SPECTRUM OF VISIBLE LIGHT AND HAVING A REFRACTIVE INDEX GREATER THAN THAT OF THE SURROUNDING MEDIUM, THE MASK HAVING A PLURALITY OF SECTIONS DIFFERING PROGRESSIVELY IN THICKNESS BY DISCRETE STEPS, THE MASK BEING PLACED BETWEEN THE OPTICAL SYSTEM AND THE PLATE AND CLOSELY ADJACENT TO THE PLATE, AND SHUTTER MEANS ADAPTED TO APPROPRIATELY EXPOSE THE PLATE TO THE IMAGE OF THE TEST PATTERN PRODUCED BY THE OPTICAL SYSTEM, WHEREBY AN IMAGE IS OBTAINED ON THE PHOTOGRAPHIC PLATE HAVING A PLURALITY OF SECTIONS REPRESENTING THE FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM FOR A LIKE PLURALITY OF SLIGHTLY DIFFERING EFFECTIVE DISTANCES BETWEEN THE OPTICAL SYSTEM AND THE PHOTOGRAPHIC PLATE, RESPECTIVELY, FROM WHICH THE OPTIMUM DISTANCE FOR THE CLEAREST ACTUAL FOCUS AND RESOLUTION OF THE OPTICAL SYSTEM CAN BE DEDUCED.
References Cited (Backward Citations)
DE741508C
Cited
US2777355A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-08-05 | 1967-02-04 | 1967-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-08-05 | 1971-02-04 | 1971-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-08-05 | 1975-02-04 | 1975-08-06 | $7700.00 | Window Closed / Lapsed |