US4364650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure control method and device
Assignee: Fujifilm Holdings Corp
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Filing: 1980-10-03
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Granted: 1982-12-21
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Expires: 2000-10-03
Abstract
Abstract A number of light measuring elements are arranged at various portions of an image of an object focused by an objective. The light measuring elements are grouped for different zones to measure the average brightness of the image within the respective zones. The average brightness of the image is weighed and added together to calculate the brightness of the object based on which the exposure is controlled.
Inventors
- 👤 Takaaki Terashita
- 👤 Kazuo Shiota
- 👤 Kenji Nakauchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:47
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/091
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
172 words
A method of controlling exposure based on the brightness of an object measured by light measuring means comprising steps of arranging a number of light measuring elements in a light measuring area for measuring the brightness of the object the image of which is focused on said light measuring area, said light measuring elements outputing a signal representing the brightness measured thereby, dividing said light measuring area into n-number of zones of a desired pattern, each zone including at least one of said light measuring elements, obtaining an average brightness Bmi (i: address of the zone) of said zone by calculation based on the output signals of said light measuring elements, obtaining the object brightness B by calculation based on said average brightness Bmi by use of a formula of ##EQU2## where K 1 and K i+1 are coefficients, controlling exposure based on the object of brightness B; and dividing said light measuring area into different patterns of zones for different positions of the optical instrument to which the method is applied.
Claim 2
Independent Claim
172 words
A method of controlling exposure based on the brightness of an object measured by light measuring means comprising steps of arranging a number of light measuring elements in a light measuring area for measuring the brightness of the object the image of which is focused on said light measuring area, said light measuring elements outputing a signal representing the brightness measured thereby, dividing said light measuring area into n-number of zones of a desired pattern, each zone including at least one of said light measuring elements, obtaining an average brightness Bmi (i: address of the zone) of said zone by calculation based on the output signals of said light measuring elements, obtaining the object brightness B by calculation based on said average brightness Bmi by use of a formula of ##EQU2## where K 1 and K i+1 are coefficients, controlling exposure based on the object of brightness B; and dividing said light measuring area into different patterns of zones for different positions of the optical instrument to which the method is applied.
Claim 3
Independent Claim
187 words
A method of controlling exposure based on the brightness of an object measured by light measuring means comprising steps of arranging a number of light measuring elements in a light measuring area for measuring the brightness of the object the image of which is focused on said light measuring area, said light measuring elements outputing a signal representing the brightness measured thereby, dividing said light measuring area into n-number of zones of a desired pattern, each zone including at least one of said light measuring elements, obtaining an average brightness Bmi (i: address of the zone) of said zone by calculation based on the output signals of said light measuring elements, obtaining the object brightness B by calculation based on said average brightness Bmi by use of a formula of ##EQU3## where K 1 and K i+1 are coefficients, controlling exposure based on the object of brightness B; dividing said light measuring area into different patterns of zones for different positions of the optical instrument to which the method is applied; and dividing said light measuring area into different patterns of zones for different kinds of objects.
Claim 4
Independent Claim
187 words
A method of controlling exposure based on the brightness of an object measured by light measuring means comprising steps of arranging a number of light measuring elements in a light measuring area for measuring the brightness of the object the image of which is focused on said light measuring area, said light measuring elements outputing a signal representing the brightness measured thereby, dividing said light measuring area into n-number of zones of a desired pattern, each zone including at least one of said light measuring elements, obtaining an average brightness Bmi (i: address of the zone) of said zone by calculation based on the output signals of said light measuring elements, obtaining the object brightness B by calculation based on said average brightness Bmi by use of a formula of ##EQU3## where K 1 and K i+1 are coefficients, controlling exposure based on the object of brightness B; dividing said light measuring area into different patterns of zones for different positions of the optical instrument to which the method is applied; and dividing said light measuring area into different patterns of zones for different kinds of objects.
Claim 5
Dependent Claim
140 words
An exposure control device for controlling exposure based on the brightness of an object measured by light measuring means which measures the brightness of the object the image of which is focused on a light measuring area wherein the improvement comprises; a number of light measuring elements arranged in said light measuring area, means for obtaining an average output of the outputs of said light measuring elements in each zone, means for weighting the averaged outputs and summing up the weighted outputs, means for controlling exposure based on the brightness of the object obtained by summing up the weighted outputs; and said light measuring elements being connected to one input terminal of an operational amplifier by way of analog gates, said analog gates being selectively turned on to input desired outputs of the light measuring elements into said operational amplifier.
Claim 6
Dependent Claim
140 words
An exposure control device for controlling exposure based on the brightness of an object measured by light measuring means which measures the brightness of the object the image of which is focused on a light measuring area wherein the improvement comprises; a number of light measuring elements arranged in said light measuring area, means for obtaining an average output of the outputs of said light measuring elements in each zone, means for weighting the averaged outputs and summing up the weighted outputs, means for controlling exposure based on the brightness of the object obtained by summing up the weighted outputs; and said light measuring elements being connected to one input terminal of an operational amplifier by way of analog gates, said analog gates being selectively turned on to input desired outputs of the light measuring elements into said operational amplifier.
References Cited (Backward Citations)
US3790275A
Cited
US4075640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |