US3580149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter correction device
Assignee: Fujifilm Holdings Corp
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Filing: 1967-10-23
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Granted: 1971-05-25
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Expires: 1987-10-23
Abstract
Abstract A filter correction device including a pair of filters of different spectral characteristics, each filter of which is moved in and out of alignment with the optical axis of the camera lens system automatically by an electric motor responsive to closure of the normally open switch to achieve color correction in accordance with the spectral characteristics of the illuminated object to be photographed.
Inventors
- 👤 Shin Fujisawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:13
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/02; G03B17/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
177 words
In a camera including a camera lens system for transferring light to a photosensitive film and a photoelectric element for controlling exposure of said film, the improvement comprising: a shiftable, light balancing combined filter assembly comprising individual filters for simultaneous optical alignment with said photosensitive element and said camera lens system when said assembly is in a first position and clear windows optically aligned therewith when said assembly is in a second position, an electrical motor for moving said filter assembly between positions, a source of electrical energy, and a relay switch for coupling said source of electrical energy to said motor means and a bridge circuit including light receptors in the form of photosensitive resistances, operatively connected to light filters having different spectral characteristics which receive illuminated light from the object being photographed whereby the shiftable combined filter assembly automatically corrects the light transmitted by the camera lens system to the photosensitive film and the light falling on said photosensitive element controls the exposure of said film, depending upon the spectral characteristics of the illuminated object.
Claim 2
Dependent Claim
177 words
In a camera including a camera lens system for transferring light to a photosensitive film and a photoelectric element for controlling exposure of said film, the improvement comprising: a shiftable, light balancing combined filter assembly comprising individual filters for simultaneous optical alignment with said photosensitive element and said camera lens system when said assembly is in a first position and clear windows optically aligned therewith when said assembly is in a second position, an electrical motor for moving said filter assembly between positions, a source of electrical energy, and a relay switch for coupling said source of electrical energy to said motor means and a bridge circuit including light receptors in the form of photosensitive resistances, operatively connected to light filters having different spectral characteristics which receive illuminated light from the object being photographed whereby the shiftable combined filter assembly automatically corrects the light transmitted by the camera lens system to the photosensitive film and the light falling on said photosensitive element controls the exposure of said film, depending upon the spectral characteristics of the illuminated object.
Claim 3
Dependent Claim
78 words
The camera as claimed in claim 1, where tungsten-type film is employed and said light balancing filter assembly includes an amber-type filter for optical aligning with the camera lens system and said bridge circuit is so arranged that said relay switch contacts are closed when said object to be photographed is illuminated by daylight and wherein in response to closure of said switch contacts, said electric motor moves said shiftable light balancing filter assembly to said first position.
Claim 4
Dependent Claim
60 words
The camera as claimed in claim 1, wherein daylight-type film is employed and wherein said light balancing filter optically aligned with said camera lens system comprises a blue-type filter and said bridge circuit is such that closure of said relay switch causes said motor to shift said filter assembly to said first position when said object is illuminated by daylight.
Claim 5
Dependent Claim
51 words
The camera as claimed in claim 2, wherein said shiftable light balancing filter assembly includes an ND filter for optical alignment with said photoelectric element in response to closure of said relay switch contacts and movement of said combined filter assembly to the first position under energization of said electric motor.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |