US5481329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus condition detecting device
Assignee: Nikon Corp
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Filing: 1995-01-23
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Granted: 1996-01-02
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Expires: 2015-01-23
Abstract
Abstract A focus condition detecting device comprises an object judgment means to judge an object pattern condition on the basis of the output signal provided by the image sensor in proportion to the object light in a photographing field having passed through the photographing lens and an operation means to detect the focus condition by means of a selected method which is either a first operation method in which the focus condition of the photographing lens is detected on the basis of the data obtained through first filtering of the output signal or a second operation method in which the focus condition of the photographing lens is detected on the basis of the data obtained through second filtering of the output signal according to the judgment result of the object judgment means. For example, in the first filtering, the DC component is completely removed, while in the second filtering, the DC component is not completely removed.
Inventors
- 👤 Shigeyuki Uchiyama
- 👤 Yosuke Kusaka
- 👤 Syozo Yamano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:33
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/32
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
152 words
A focus condition detecting device comprising: an image sensor that includes a plurality of photoelectric elements and outputs a signal in proportion to the intensity of incoming object light; an optical system that directs said object light in a photographic field having passed a photographing lens to said image sensor; pattern judgment means for judging whether an object pattern is a specific pattern including a fine pattern and/or a low contrast pattern on the basis of the output signal from said image sensor; and operation means or calculating the focus condition of the photographing lens on the basis of the data obtained through a first filtering of the output signal when said object pattern is judged by said pattern judgment means to be a specific pattern, or through a second filtering of the output signal when said object pattern is judged by said pattern judgment means not to be a specific pattern.
Claim 2
Dependent Claim
152 words
A focus condition detecting device comprising: an image sensor that includes a plurality of photoelectric elements and outputs a signal in proportion to the intensity of incoming object light; an optical system that directs said object light in a photographic field having passed a photographing lens to said image sensor; pattern judgment means for judging whether an object pattern is a specific pattern including a fine pattern and/or a low contrast pattern on the basis of the output signal from said image sensor; and operation means or calculating the focus condition of the photographing lens on the basis of the data obtained through a first filtering of the output signal when said object pattern is judged by said pattern judgment means to be a specific pattern, or through a second filtering of the output signal when said object pattern is judged by said pattern judgment means not to be a specific pattern.
Claim 3
Dependent Claim
46 words
A focus condition detecting device according to claim 1, wherein said first filtering is a differential filtering to remove a DC component of said object pattern and said second filtering is a filtering that does not necessarily remove the DC component of said object pattern completely.
Claim 4
Dependent Claim
81 words
A focus condition detecting device according to claim 1, wherein said pattern judgment means judges said object pattern to be said specific pattern when: (1) a number of ranges having a contrast among a plurality of ranges into which said signal output from said image sensor is divided is no more than a predetermined value; and (2) a sum of differences between said signal outputs from adjacent ranges of said a plurality of ranges is no more than a predetermined value.
Claim 5
Independent Claim
122 words
A method for detecting focus condition on the basis of an output signal on proportion to the intensity of an object light incident on an image sensor through an optical system, said method comprising the steps of: judging whether an object pattern is a specific pattern including a fine pattern and/or a low contrast pattern on the basis of the output signal from said image sensor; and calculating the focus condition of a photographing lens on the basis of the data obtained through a first filtering of the output signal when said object pattern is judged to be a specific pattern or through a second filtering of the output signal when said object pattern is judged not to be a specific pattern.
Claim 6
Independent Claim
122 words
A method for detecting focus condition on the basis of an output signal on proportion to the intensity of an object light incident on an image sensor through an optical system, said method comprising the steps of: judging whether an object pattern is a specific pattern including a fine pattern and/or a low contrast pattern on the basis of the output signal from said image sensor; and calculating the focus condition of a photographing lens on the basis of the data obtained through a first filtering of the output signal when said object pattern is judged to be a specific pattern or through a second filtering of the output signal when said object pattern is judged not to be a specific pattern.
Claim 7
Dependent Claim
145 words
A focus condition detecting device comprising: an image sensor that includes a plurality of photoelectric elements and outputs an output signal in proportion to the intensity of incoming object light; an optical system that directs said incoming object light in a photographic field having passed a photographing lens to said image sensor; a pattern judgment circuit that judges whether an object pattern is a specific pattern including at least one of a fine pattern and a low contrast pattern based on the output signal from said image sensor; and an operation circuit that determines the focus condition of the photographing lens based on data obtained through a first filtering of the output signal when said object pattern is judged by said pattern judgment circuit to be a specific pattern, said first filtering being a differential filtering to remove a DC component of said object pattern.
Claim 8
Dependent Claim
145 words
A focus condition detecting device comprising: an image sensor that includes a plurality of photoelectric elements and outputs an output signal in proportion to the intensity of incoming object light; an optical system that directs said incoming object light in a photographic field having passed a photographing lens to said image sensor; a pattern judgment circuit that judges whether an object pattern is a specific pattern including at least one of a fine pattern and a low contrast pattern based on the output signal from said image sensor; and an operation circuit that determines the focus condition of the photographing lens based on data obtained through a first filtering of the output signal when said object pattern is judged by said pattern judgment circuit to be a specific pattern, said first filtering being a differential filtering to remove a DC component of said object pattern.
Claim 9
Dependent Claim
69 words
A focus condition detecting device according to claim 5, wherein when said object pattern is judged by said pattern judgment circuit not to be a specific pattern, said operation circuit determines the focus condition of the photographing lens based on data obtained through a second filtering of the output signal, said second filtering being a filtering that does not necessarily completely remove the DC component of said object pattern.
Claim 10
Dependent Claim
76 words
A focus condition detecting device according to claim 5, wherein said pattern judgment circuit judges said object pattern to be said specific pattern when: (1) a number of ranges having a contrast among a plurality of ranges into which said output signal is divided is no greater than a first value; and (2) a sum of differences between output signal outputs from adjacent ranges of said plurality of ranges is no greater than a second value.
Claim 11
Independent Claim
134 words
A method for detecting focus condition based on an output signal that is proportional to an intensity of object light incident on an image sensor through an optical system, said optical system directing said object light in a photographic field having passed a photographing lens to said image sensor, said method comprising the steps of: judging whether an object pattern is a specific pattern including at least one of a fine pattern and a low contrast pattern based on the output signal from said image sensor; and determining the focus condition of the photographing lens based on data obtained through a first filtering of the output signal when said object pattern is judged to be a specific pattern, said first filtering being a differential filtering to remove a DC component of said object pattern.
Claim 12
Independent Claim
134 words
A method for detecting focus condition based on an output signal that is proportional to an intensity of object light incident on an image sensor through an optical system, said optical system directing said object light in a photographic field having passed a photographing lens to said image sensor, said method comprising the steps of: judging whether an object pattern is a specific pattern including at least one of a fine pattern and a low contrast pattern based on the output signal from said image sensor; and determining the focus condition of the photographing lens based on data obtained through a first filtering of the output signal when said object pattern is judged to be a specific pattern, said first filtering being a differential filtering to remove a DC component of said object pattern.
Claim 13
Dependent Claim
71 words
A method for detecting focus condition according to claim 8, wherein when said object pattern is judged not to be a specific pattern in said judging step, the focus condition of the photographing lens is calculated based on data obtained through a second filtering of the output signal in said determining step, said second filtering being a filtering that does not necessarily completely remove the DC component of said object pattern.
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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) | 1999-01-01 | 1999-07-03 | 2000-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-01 | 2007-07-03 | 2008-01-02 | $7700.00 | Window Closed / Lapsed |