EP0440171A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Camera
Assignee: Canon Inc
•
Filing: 1991-01-29
•
Granted: —
•
Expires: 2011-01-29
Abstract
Abstract A camera comprising a detection circuit for dividing a field of view into plural small areas and detecting luminance for each of the plural small areas, a focus detecting circuit capable of making focus detecting for each of plural focus detecting areas in the field of view, a selection circuit for selecting at least one of the plural focus detecting areas to be handled by the focus detecting circuit, and a decision circuit for deciding the necessity of flash illumination by using first luminance information detected by the detection circuit for the small area containing the focus detecting area selected by the selection circuit and second luminance information for the small area having a maximum luminance among the plural small areas. The camera can precisely determine a backlighting condition in particular.
Inventors
- 👤 Shingo Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:16
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/34; G02B7/346
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
121 words
A camera comprising: (a) detection means for dividing a field of view into plural small area and detecting luminance for each of said plural small areas; (b) focus detecting means capable of making focus detection for each of plural focus detecting areas in said field of view; (c) selection means for selecting at last one of said plural focus detecting areas to be handled by said focus detecting means; and (d) decision means for deciding the necessity of flash illumination by using first luminance information detected by said detection means for the small area containing the focus detecting area selected by said selection means and second luminance information for the small area having a maximum luminance among said plural small areas.
Claim 2
Dependent Claim
33 words
A camera according to claim 1, wherein said decision means decides the necessity of said flash illumination based on comparison information obtained by comparing said first luminance information and said second luminance information.
Claim 3
Dependent Claim
27 words
A camera according to claim 2, wherein said decision means makes decision to trigger said flash illumination when said comparison information is larger than a predetermined value.
Claim 4
Dependent Claim
41 words
A camera according to claim 1, further comprising light measurement value calculating means for arithmetically processing said luminance for each of said plural small areas obtained by said detection means to determine a light measurement value of said field of view.
Claim 5
Dependent Claim
43 words
A camera according to claim 4, wherein said light measurement value calculating means combines said plural small areas to form plural medium areas, and determines said light measurement value of said field of view by using luminance information of said plural medium areas.
Claim 6
Dependent Claim
41 words
A camera according to claim 3, further comprising light measurement value calculating means for arithmetically processing said luminance for each of said plural small areas obtained by said detection means to determine a light measurement value of said field of view.
Claim 7
Dependent Claim
43 words
A camera according to claim 6, wherein said light measurement value calculating means combines said plural small areas to form plural medium areas, and determines said light measurement value of said field of view by using luminance information of said plural medium areas.
Claim 8
Dependent Claim
25 words
A camera according to claim 1, wherein said focus detecting means can make focus detection for said plural focus detecting areas independently of one another.
Claim 9
Dependent Claim
49 words
A camera according to claim 1, wherein said selection means has a manual mode in which a photographer selects one of said plural focus detecting areas with one's own intention, and an automatic mode in which one of said plural focus detecting areas is selected by a present program.
Claim 10
Dependent Claim
25 words
A camera according to claim 9, wherein the focus detecting area having the nearest object distance is selected by said program in said automatic mode.
Claim 11
Dependent Claim
117 words
A camera comprising: (a) detection means for dividing a field of view into plural small areas and detecting luminance for each of said plural small areas; (b) focus detecting means capable of making focus detection for each of plural focus detecting areas in said field of view; (c) selection means for selecting at least one of said plural focus detecting areas to be handled by said focus detecting means; and (d) decision means for deciding the necessity of flash illumination when a difference between first luminance information detected by said detection means for the small area containing the focus detecting area selected by said selection means and at least one luminance information among said plural small areas.
Claim 12
Dependent Claim
41 words
A camera according to claim 11, further comprising light measurement value calculating means for arithmetically processing said luminance for each of said plural small areas obtained by said detection means to determine a light measurement value of said field of view.
Claim 13
Dependent Claim
43 words
A camera according to claim 12, wherein said light measurement value calculating means combines said plural small areas to form plural medium areas, and determines said light measurement value of said field of view by using luminance information of said plural medium areas.
Claim 14
Dependent Claim
25 words
A camera according to claim 11, wherein said focus detecting means can make focus detection for said plural focus detecting areas independently of one another.
Claim 15
Dependent Claim
49 words
A camera according to claim 11, wherein said selection means has a manual mode in which a photographer selects one of said plural focus detecting areas with one's own intention, and an automatic mode in which one of said plural focus detecting areas is selected by a preset program.
Claim 16
Dependent Claim
25 words
A camera according to claim 15, wherein the focus detecting area having the nearest object distance is selected by said program in said automatic mode.
Claim 17
Dependent Claim
41 words
A camera according to claim 8, wherein said focus detecting means has plural sets of focus detecting devices, and can determine an in-focus state and a defocus amount of an object for each of said focus detecting areas in each set.
Claim 18
Dependent Claim
41 words
A camera according to claim 14, wherein said focus detecting means has plural sets of focus detecting devices, and can determine an in-focus state and a defocus amount of an object for each of said focus detecting areas in each set.
Claim 19
Dependent Claim
98 words
A camera comprising: (a) detection means for dividing a field of view into plural small areas and detecting luminance for each of said plural small areas; (b) comparison means for detecting a difference between first luminance information detected by said detection means for a specified small area in said plural small areas and second luminance information indicating a maximum luminance value among said plural small areas; and (c) decision means for deciding the necessity of flash illumination by comparing the difference information determined by said comparison means with a predetermined value variable depending on said first luminance information.
Claim 20
Dependent Claim
26 words
A camera according to claim 19, further comprising focus detecting means for detecting an in-focus state of a focus detecting area in said field of view.
Claim 21
Dependent Claim
31 words
A camera according to claim 20, wherein said specified small area handled by said comparison means is the small area containing said focus detecting area detected by said focus detecting means.
Claim 22
Dependent Claim
27 words
A camera according to claim 20, wherein said focus detecting means can make focus detection for each of plural focus detecting areas in said field of view.
Claim 23
Dependent Claim
34 words
A camera according to claim 22, wherein said specified small area handled by said comparison means is the small area containing the focus detecting area selected to be detected by said focus detecting means.
Claim 24
Dependent Claim
41 words
A camera according to claim 19, further comprising light measurement value calculating means for arithmetically processing said luminance for each of said plural small areas obtained by said detection means to determine a light measurement value of said field of view.
Claim 25
Dependent Claim
43 words
A camera according to claim 24, wherein said light measurement value calculating means combines said plural small areas to form plural medium area, and determines said light measurement value of said field of view by using luminance information of said plural medium areas.
References Cited (Backward Citations)
JPS537330B2
Cited
JPS519271Y1
Cited
US4339185A
Cited
GB2077448A
Cited
FR2539519A1
Cited
US4746947A
Cited
US4912495A
Cited
US4774401A
Cited
US4745427A
Cited
US4786935A
Cited
JPS62203022A
Cited
DE3803305A1
Cited
JPH01202720A
Cited
JPH01280737A
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.