Patent US4182573A successfully refreshed from Google Patents.
US4182573A
Expired / Lapsed
US
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Exposure meter
Assignee: Minolta Co Ltd
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Filing: 1977-08-15
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Granted: 1980-01-08
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Expires: 1997-08-15
Abstract
Abstract An exposure meter for use in photography which includes means for measuring brightness at a plurality of places in a scene to be measured for exposure, means for calculating frequency distribution of the brightness which divides brightness value into many stages and counts frequency of occurrence of brightness at each of the stages, and means for calculating, under designated conditions, position whereat film latitude is to be present within the width of the brightness distribution.
Inventors
- 👤 Seiji Yamada
- 👤 Ichiro Yoshiyama
- 👤 Mashio Kitaura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:28
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
105 words
An exposure meter for use in photography comprising: a means for measuring the brightness of a scene to be photographed at a plurality of places; a means for calculating the frequency distribution of brightness of said scene by dividing the measured brightness into a plurality of ranges and counting the number of said plurality of places having measured brightness within each of said plurality of brightness ranges; and a means for calculating the exposure amount at which the film exposure latitude of a film to be used in the photography is in a predetermined relationship relative to said frequency distribution of brightness of said scene.
Claim 2
Dependent Claim
105 words
An exposure meter for use in photography comprising: a means for measuring the brightness of a scene to be photographed at a plurality of places; a means for calculating the frequency distribution of brightness of said scene by dividing the measured brightness into a plurality of ranges and counting the number of said plurality of places having measured brightness within each of said plurality of brightness ranges; and a means for calculating the exposure amount at which the film exposure latitude of a film to be used in the photography is in a predetermined relationship relative to said frequency distribution of brightness of said scene.
Claim 3
Dependent Claim
49 words
An exposure meter for use in photography as claimed in claim 1, wherein said means for calculating the exposure amount further comprises: a change over means for selecting one of a plurality of predetermined relationships of the film latitude relative to said frequency distribution of brightness of said scene.
Claim 4
Dependent Claim
35 words
An exposure meter as claimed in claim 1, wherein: said predetermined relationship comprises the center of the film latitude being midway between the maximum brightness and the minimum brightness of the scene to be photographed.
Claim 5
Dependent Claim
52 words
An exposure meter as claimed in claim 1, wherein: said predetermined relationship comprises the number of said plurality of places having brightness less than the minimum of the film exposure latitude being equal to the number of said plurality of places having brightness greater than the maximum of the film exposure latitude.
Claim 6
Dependent Claim
29 words
An exposure meter as claimed in claim 1, wherein: said predetermined relationship comprises having the maximum number of said plurality of places with brightness within the film exposure latitude.
Claim 7
Dependent Claim
32 words
An exposure meter as claimed in claim 1, wherein: said predetermined relationship comprises the minimum of the film exposure latitude being equal to the minimum brightness of the scene to be photographed.
Claim 8
Dependent Claim
32 words
An exposure meter as claimed in claim 1, wherein: said predetermined relationship comprises the maximum of the film exposure latitude being equal to the maximum brightness of the scene to be photographed.
Claim 9
Dependent Claim
44 words
An exposure meter as claimed in claim 1, wherein: said means for calculating the frequency distribution of brightness comprises means for counting the number of places exceeding a predetermined number, which places have a measured brightness within each of said plurality of brightness ranges.
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) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |