EP0416904A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Exposure control device in a camera
Assignee: Nikon Corp
•
Filing: 1990-09-05
•
Granted: —
•
Expires: 2010-09-05
Abstract
Abstract An exposure control device in a camera comprises focus detection means for calculating a plurality of defocus amounts corresponding to a plurality of focus detection areas, weight producing means for producing a plurality of weights corresponding to the plurality of focus detection areas on the basis of the plurality of defocus amounts, light metering means for light-metering a plurality of light metering areas at least partly overlapping with the plurality of focus detection areas and producing a plurality of light metering outputs, and exposure amount calculating means for calculating a proper exposure amount on the basis of the plurality of weights and the plurality of light metering outputs.
Inventors
- 👤 Tadao Takagi
- 👤 Tadao Kai
- 👤 Shigeyuki Uchiyama
- 👤 Hiroyuki Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:11
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
An exposure control device in a camera comprising: focus detection means for calculating a plurality of defocus amounts corresponding to a plurality of focus detection areas; weight producing means for producing a plurality of weights corresponding to said plurality of focus detection areas on the basis of said plurality of defocus amounts; light metering means for light-metering a plurality of light metering areas at least partly overlapping with said plurality of focus detection areas and producing a plurality of light metering outputs; and exposure amount calculating means for calculating a proper exposure amount on the basis of said plurality of weights and said plurality of light metering outputs.
Claim 2
Dependent Claim
108 words
An exposure control device in a camera comprising: focus detection means for calculating a plurality of defocus amounts corresponding to a plurality of focus detection areas; weight producing means for producing a plurality of weights corresponding to said plurality of focus detection areas on the basis of said plurality of defocus amounts; light metering means for light-metering a plurality of light metering areas at least partly overlapping with said plurality of focus detection areas and producing a plurality of light metering outputs; and exposure amount calculating means for calculating a proper exposure amount on the basis of said plurality of weights and said plurality of light metering outputs.
Claim 3
Dependent Claim
91 words
A device according to Claim 1, wherein for a defocus amount indicative of the fact that the object image is on the object side relative to a film surface and a defocus amount indicative of the fact that the object image is on the camera side relative to the film surface, said weight producing means produces the weights so that even if the absolute values of said two defocus amounts one equal to each other, the values of the weights corresponding to said two defocus amounts may differ from each other.
Claim 4
Dependent Claim
64 words
A device according to Claim 1, wherein said focus detection means has a plurality of photoelectric conversion elements and calculates said plurality of defocus amounts from the outputs of said plurality of photoelectric conversion elements, and said light metering means produces said plurality of light metering outputs on the basis of the outputs of at least some of said plurality of photoelectric conversion elements.
Claim 5
Dependent Claim
80 words
A device according to Claim 1, further having exposure control means for controlling exposure on the basis of the output of said exposure amount calculating means, said exposure amount calculating means calculating the average luminance value of said plurality of light metering areas on the basis of said plurality of light metering outputs, and outputting a signal conforming to said average luminance value to said exposure control means when the sum of said plurality of weights is a predetermined value.
Claim 6
Dependent Claim
80 words
A device according to Claim 1, wherein said exposure amount calculating means calculates the average luminance value of a plurality of areas not including said plurality of focus detection areas in said plurality of light metering areas on the basis of said plurality of light metering outputs, calculates the weighted mean luminance value of said plurality of light metering areas on the basis of said plurality of weights, and compares said average luminance value with said weighted means luminance value.
Claim 7
Dependent Claim
61 words
A device according to Claim 5, further having exposure control means for controlling exposure on the basis of the output of said exposure amount calculating means, said exposure amount calculating means outputting a signal conforming to said weighted mean luminance value to said exposure control means when said average luminance value minus said weighted mean luminance value exceeds a predetermined value.
Claim 8
Dependent Claim
77 words
A device according to Claim 5, further having exposure control means for controlling exposure on the of the output of said exposure amount calculating means, said exposure amount calculating means calculating a proper luminance value from said average luminance value and said weighted mean luminance value when said average luminance value minus said weighted mean luminance value on the basis of said average luminance value and said weighted mean luminance value does not exceed a predetermined value.
Claim 9
Dependent Claim
75 words
A device according to Claim 1, wherein said exposure amount calculating means calculates the average luminance value of said plurality of light metering areas on the basis of said plurality of light metering outputs, calculates the weighted mean luminance value of said plurality of light metering areas on the basis of said plurality of weights, and calculates a proper luminance value on the basis of said average luminance value and said weighted mean luminance value.
Claim 10
Dependent Claim
189 words
An exposure control device in a camera comprising: focus detection means for calculating a plurality of defocus amounts corresponding to a plurality of focus detection areas; weight producing means for producing a plurality of weights corresponding to said plurality of focus detection areas on the basis of said plurality of defocus amounts; first light metering means for light-metering a plurality of light metering areas at least partly overlapping with said plurality of focus detection areas and producing a plurality of first light metering outputs; second light metering means for light-metering at least one other area than said plurality of light metering areas and producing at least one second light metering output; and exposure amount calculating means for calculating a proper exposure amount on the basis of at least said plurality of first light metering outputs when at least one of said plurality of defocus amounts is within a predetermined range, and calculating a proper exposure amount on the basis of said at least one second light metering output without the use of said plurality of first light metering outputs when said plurality of defocus amounts exceed said predetermined range.
Claim 11
Dependent Claim
189 words
An exposure control device in a camera comprising: focus detection means for calculating a plurality of defocus amounts corresponding to a plurality of focus detection areas; weight producing means for producing a plurality of weights corresponding to said plurality of focus detection areas on the basis of said plurality of defocus amounts; first light metering means for light-metering a plurality of light metering areas at least partly overlapping with said plurality of focus detection areas and producing a plurality of first light metering outputs; second light metering means for light-metering at least one other area than said plurality of light metering areas and producing at least one second light metering output; and exposure amount calculating means for calculating a proper exposure amount on the basis of at least said plurality of first light metering outputs when at least one of said plurality of defocus amounts is within a predetermined range, and calculating a proper exposure amount on the basis of said at least one second light metering output without the use of said plurality of first light metering outputs when said plurality of defocus amounts exceed said predetermined range.
Claim 12
Independent Claim
52 words
A method of determining an exposure value for a camera by taking into account the amount of detected light from respective light-metering areas, characterised in that the respective amounts are each weighted in accordance with a respective defocus amount associated with an area which at least partially overlaps the respective light-metering area.
Claim 13
Independent Claim
52 words
A method of determining an exposure value for a camera by taking into account the amount of detected light from respective light-metering areas, characterised in that the respective amounts are each weighted in accordance with a respective defocus amount associated with an area which at least partially overlaps the respective light-metering area.
Claim 14
Dependent Claim
45 words
A method as claimed in claim 10, including the step of checking whether any of said defocus amounts is within a predetermined range and, if not, calculating the exposure value instead on the basis of the amount of detected light from a further light-metering area.
Claim 15
Independent Claim
86 words
A method of determining an exposure value for a camera, wherein (a) the defocus amounts for respective focus detection areas are checked to determine whether any lie within a predetermined range; (b) if so, the exposure value is calculated on the basis of the amounts of detected light from respective light-metering areas each at least partially overlapping a focus detection area; and (c) if not, the exposure value is calculated on the basis of the amount of detected light from at least one further light-metering area.
Claim 16
Independent Claim
86 words
A method of determining an exposure value for a camera, wherein (a) the defocus amounts for respective focus detection areas are checked to determine whether any lie within a predetermined range; (b) if so, the exposure value is calculated on the basis of the amounts of detected light from respective light-metering areas each at least partially overlapping a focus detection area; and (c) if not, the exposure value is calculated on the basis of the amount of detected light from at least one further light-metering area.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.