US5333028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic focusing apparatus detecting focus for a plurality of areas and using contrast levels
Assignee: Canon Inc
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Filing: 1992-06-26
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Granted: 1994-07-26
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Expires: 2012-06-26
Abstract
Abstract A focus detection apparatus or a camera having such a focus detection apparatus includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state comprises a calculating circuit for calculating a plurality of contrast levels represented by outputs from the sensor sections. A selector is provided for selecting one of the outputs from the sensor sections on the basis of focus detection characteristic data respectively predetermined for said sensor sections and the contrast levels of the sensor sections. The selector includes a comparison circuit with compares the contrast levels of each sensor section with data corresponding to the characteristic data of said each sensor section, the selector selecting the one of the outputs based on the comparison of the plurality of sensor section outputs by the comparison circuit.
Inventors
- 👤 Akira Akashi
- 👤 Terutake Kadohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:47
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/34; G02B7/346
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
145 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating a plurality of contrast levels represented by outputs from said sensor sections; and (b) a selector for selecting one of the outputs from said sensor sections on the basis of focus detection characteristic data respectively predetermined for said sensor sections and the contrast levels of said sensor sections, said selector including a comparison circuit which compares the contrast levels of each sensor section in consideration of data corresponding to the focus detection characteristic data of said each sensor section, said selector selecting at least said one of the outputs based on the comparison of the plurality of sensor section outputs by said comparison circuit.
Claim 2
Dependent Claim
145 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating a plurality of contrast levels represented by outputs from said sensor sections; and (b) a selector for selecting one of the outputs from said sensor sections on the basis of focus detection characteristic data respectively predetermined for said sensor sections and the contrast levels of said sensor sections, said selector including a comparison circuit which compares the contrast levels of each sensor section in consideration of data corresponding to the focus detection characteristic data of said each sensor section, said selector selecting at least said one of the outputs based on the comparison of the plurality of sensor section outputs by said comparison circuit.
Claim 3
Dependent Claim
50 words
A focus detection apparatus or a camera having said focus detection apparatus according to claim 1, wherein said comparison circuit compares the contrast levels of said sensor sections with values obtained by multiplying the characteristic data with the contrast levels to select one of the outputs from said sensor sections.
Claim 4
Dependent Claim
157 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels and focus amounts for each of said sensor sections; and (b) an output circuit for selecting one of the focus amounts calculated by said calculating circuit and outputting the selected focus amount as a focus detection result on the basis of focus detection characteristic data respectively predetermined for said sensor sections and the contrast levels of said sensor sections, said selector including a comparison circuit which compares the contrast levels of each sensor section in consideration of data corresponding to the focus detection characteristic data of said each sensor section, said selector selecting said one of the focus amounts based on the comparison of the plurality of sensor section outputs by said comparison circuit.
Claim 5
Dependent Claim
157 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels and focus amounts for each of said sensor sections; and (b) an output circuit for selecting one of the focus amounts calculated by said calculating circuit and outputting the selected focus amount as a focus detection result on the basis of focus detection characteristic data respectively predetermined for said sensor sections and the contrast levels of said sensor sections, said selector including a comparison circuit which compares the contrast levels of each sensor section in consideration of data corresponding to the focus detection characteristic data of said each sensor section, said selector selecting said one of the focus amounts based on the comparison of the plurality of sensor section outputs by said comparison circuit.
Claim 6
Dependent Claim
51 words
A focus detection apparatus or a camera having said focus detection apparatus according to claim 3, wherein said comparison circuit compares the contrast levels of said sensor sections with values obtained by multiplying the characteristic data with the contrast levels to select one of the focus amounts from said sensor sections.
Claim 7
Dependent Claim
127 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels represented by outputs from said sensor sections on the basis of the outputs from said sensor section; and (b) a selector for selecting at least one of the outputs of said sensor sections on the basis of contrast values respectively obtained by weighting the contrast levels in said sensor sections in accordance with focus detection characteristic data for each sensor section, said selector including a comparison circuit which compares the contrast levels of each said sensor section for selecting said one of the outputs.
Claim 8
Dependent Claim
127 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels represented by outputs from said sensor sections on the basis of the outputs from said sensor section; and (b) a selector for selecting at least one of the outputs of said sensor sections on the basis of contrast values respectively obtained by weighting the contrast levels in said sensor sections in accordance with focus detection characteristic data for each sensor section, said selector including a comparison circuit which compares the contrast levels of each said sensor section for selecting said one of the outputs.
Claim 9
Dependent Claim
39 words
A focus detection apparatus or a camera having said focus detection apparatus according to claim 5, wherein said weighing of the contrast levels is performed on the basis of the focus detection characteristic data of each said sensor section.
Claim 10
Dependent Claim
125 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculation circuit for calculating, for each sensor section, a signal representing a reliability of focus state detection based on outputs from said each sensor section; (b) a comparison circuit for comparing the reliability signals of said sensor sections by considering predetermined focus detection characteristic data for each said sensor section; and (c) a selection circuit for, based on the result of the comparison of said comparison circuit, selecting either an output of at least one of said sensor sections or focus state information detected by the thus-determined output.
Claim 11
Dependent Claim
125 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculation circuit for calculating, for each sensor section, a signal representing a reliability of focus state detection based on outputs from said each sensor section; (b) a comparison circuit for comparing the reliability signals of said sensor sections by considering predetermined focus detection characteristic data for each said sensor section; and (c) a selection circuit for, based on the result of the comparison of said comparison circuit, selecting either an output of at least one of said sensor sections or focus state information detected by the thus-determined output.
Claim 12
Dependent Claim
24 words
A focus detection apparatus or a camera having said focus detection apparatus according to claim 7, wherein each said reliability signal represents contrast level.
Claim 13
Dependent Claim
51 words
A focus detection apparatus or a camera having said focus detection apparatus according to claim 8, wherein said comparison circuit compares the contrast levels of said sensor sections with values obtained by multiplying the characteristic data with the contrast levels to select one of the outputs of the focus state information.
Claim 14
Dependent Claim
127 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels represented by outputs from said sensor sections on the basis of the outputs from said sensor sections; (b) a transformation circuit for transforming the contrast levels calculated by said calculating circuit into transformed contrast levels in consideration of focus detection characteristic data for each of said sensor sections; and (c) a selection circuit for comparing each of the transformed contrast levels formed by said transformation circuit, and for selecting at least one of outputs of the sensor sections in accordance with the comparison result.
Claim 15
Dependent Claim
127 words
A focus detection apparatus or a camera having said focus detection apparatus which includes a plurality of sensor sections for receiving light from different areas of a scene and which detects a focus state, comprising: (a) a calculating circuit for calculating contrast levels represented by outputs from said sensor sections on the basis of the outputs from said sensor sections; (b) a transformation circuit for transforming the contrast levels calculated by said calculating circuit into transformed contrast levels in consideration of focus detection characteristic data for each of said sensor sections; and (c) a selection circuit for comparing each of the transformed contrast levels formed by said transformation circuit, and for selecting at least one of outputs of the sensor sections in accordance with the comparison result.
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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) | 1997-07-25 | 1998-01-24 | 1998-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-25 | 2002-01-24 | 2002-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-25 | 2006-01-24 | 2006-07-26 | $7700.00 | Window Closed / Lapsed |