US4843413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System which uses threshold counts to achieve automatic focus
Assignee: Eastman Kodak Co
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Filing: 1988-03-28
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Granted: 1989-06-27
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Expires: 2008-03-28
Abstract
Abstract Apparatus for generating automatic focus signals for positioning a lens includes a circuit for calculating a difference value between a selected pixel intensity level and the average value of the pixel intensities which neighbor the selected pixel. The difference value is fed to a thresholding circuit which generates a signal for clocking a downstream counter whenever the difference value exceeds a selected threshold value. The lens is repositioned until the output from the counter is a maximum thereby indicating an infocus position of the lens.
Inventors
- 👤 Lawrence E. Walther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:42
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
95 words
Apparatus for generating automatic focus signals for positioning a lens, the apparatus comprising: a. means for receiving image information which is a function of a position of the lens; b. means for selecting high frequency components of the image information; c. means for establishing a selected threshold level; d. means for choosing those high frequency components which exceed the selected threshold level; e. means for acquiring a count of high frequency components which exceed the selected threshold level; and f. means for positioning the lens so that the high frequency component count is a maximum.
Claim 2
Dependent Claim
95 words
Apparatus for generating automatic focus signals for positioning a lens, the apparatus comprising: a. means for receiving image information which is a function of a position of the lens; b. means for selecting high frequency components of the image information; c. means for establishing a selected threshold level; d. means for choosing those high frequency components which exceed the selected threshold level; e. means for acquiring a count of high frequency components which exceed the selected threshold level; and f. means for positioning the lens so that the high frequency component count is a maximum.
Claim 3
Dependent Claim
16 words
The apparatus as set forth in claim 1 wherein the image information comprises picture element information.
Claim 4
Dependent Claim
86 words
The apparatus as set forth in claim 2 wherein: a. the pixel information is related to intensities of the pixels; b. the selecting means includes (1) means for determining a difference in intensity levels between a selected pixel and at least one other pixel, and (2) means for selecting the high frequency pixels as a function of the difference in intensity levels; and c. the establishing means includes means for establishing the selected threshold level as a function of a selected difference in the intensity levels.
Claim 5
Dependent Claim
57 words
The apparatus as set forth in claim 3 wherein: a. the receiving means includes means for storing the intensity levels of the selected pixel and a pixel which neighbors the selected pixel; and b. the difference determining means includes means for subtracting the intensity level of the neighboring pixel from the intensity level of the selected pixel.
Claim 6
Independent Claim
87 words
A method for generating automatic focus signals to position a lens, the method comprising the steps of: a. receiving pixel information which is a function of a position of the lens; b. selecting high frequency components of the pixel information; c. establishing a selected threshold level; d. choosing those high frequency components which exceed the selected threshold level; e. counting the number of high frequency components which exceed the selected threshold level; and f. positioning the lens so that the high frequency component count is a maximum.
Claim 7
Independent Claim
87 words
A method for generating automatic focus signals to position a lens, the method comprising the steps of: a. receiving pixel information which is a function of a position of the lens; b. selecting high frequency components of the pixel information; c. establishing a selected threshold level; d. choosing those high frequency components which exceed the selected threshold level; e. counting the number of high frequency components which exceed the selected threshold level; and f. positioning the lens so that the high frequency component count is a maximum.
Claim 8
Dependent Claim
80 words
The method as set forth in claim 5 wherein: a. the pixel information is related to intensities of the pixels; b. the selecting step includes (i) determining a difference in intensity levels between a selected pixel and at least one other pixel, and (ii) selecting the high frequency pixels as a function of the difference in intensity levels; and c. the establishing step includes establishing the selected threshold level as a function of a selected difference in the intensity levels.
Claim 9
Dependent Claim
53 words
The apparatus as set forth in claim 6 wherein: a. the receiving step includes storing the intensity levels of the selected pixel and a pixel which neigbors the selected pixel; and b. the difference determining step includes subtracting the intensity level of the neighboring pixel from the intensity level of the selected pixel.
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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) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |