US4618239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic apparatus and measurement method of exposure conditions
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1984-10-04
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Granted: 1986-10-21
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Expires: 2004-10-04
Abstract
Abstract A photographic apparatus comprises a photoelectric camera arranged movably at the position of the lens of the photographic apparatus and a picture signal processing circuit connected electrically with the photoelectric camera and adapted to process picture signals, which have been input to the photoelectric camera, so as to measure given exposure conditions. It is possible to determine exposure conditions with good accuracy by measuring accurately variations in illumination conditions. The present invention allows highly-accurate measurements under preferred conditions.
Inventors
- 👤 Takashi Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:08
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
122 words
A photographic apparatus comprising a photographic camera including a camera lens defining an optical axis, a photoelectric camera having a light sensing means to sense light conditions of a subject to be photographed, and means to position the photoelectric camera sensing means at a location which is in effect on the optical axis of the camera lens when it is in its normal operating position, said sensing means location corresponding to the location of the lens relative to a subject to be photgraphed, wherein said apparatus further comprises a light sensor processing circuit capable of measuring illumance distribution of the surface of a subject, cos 4 θ law effects, variation in density of a image, and changes in intensity of light sources.
Claim 2
Dependent Claim
122 words
A photographic apparatus comprising a photographic camera including a camera lens defining an optical axis, a photoelectric camera having a light sensing means to sense light conditions of a subject to be photographed, and means to position the photoelectric camera sensing means at a location which is in effect on the optical axis of the camera lens when it is in its normal operating position, said sensing means location corresponding to the location of the lens relative to a subject to be photgraphed, wherein said apparatus further comprises a light sensor processing circuit capable of measuring illumance distribution of the surface of a subject, cos 4 θ law effects, variation in density of a image, and changes in intensity of light sources.
Claim 3
Dependent Claim
27 words
A photographic apparatus in accordance with claim 1, wherein the apparatus further comprises a motor controlled by a light sensor processing circuit which drives the positioning means.
Claim 4
Dependent Claim
42 words
A photographic apparatus in accordance with claim 2, wherein the apparatus including the positioning means further comprises a subject holder, a photosensitive material holder, and a lens diaphram, at least one of which is automatically adjusted by said light sensor processing circuit.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-20 | 1990-04-21 | 1990-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-20 | 1994-04-21 | 1994-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-20 | 1998-04-21 | 1998-10-21 | $7700.00 | Window Closed / Lapsed |