Covariance focus sensor
AssigneeEastman Kodak Company
InventorsJerold Burton Lisson, Norbert William Zoltowski
Life of this patent
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Abstract
A focus sensor for detecting the focus state of an image forming optical system relative to an object, the optical system having a plane of best imaging focus, includes: a plurality of image detectors located at a corresponding plurality of positions relative to the plane of best imaging focus for producing a respective plurality of image signals; and a signal processor connected to the image detectors for determining a position of best focus by calculating the covariances between respective pairs of the image signals.
Claims12
A focus sensor for detecting the focus state of an image forming optical system relative to an object, the optical system having a plane of best imaging focus, comprising:
- a) a plurality of image detectors located at a corresponding plurality of positions relative to the plane of best imaging focus for producing a respective plurality of image signals;
- and
- b) a signal processor connected to the image detectors for determining a position of best focus by calculating the covariances between respective pairs of the image signals.
A method of detecting the focus state of an image forming optical system relative to an object, the optical system having a plane of best imaging focus, comprising the steps of:
- a) providing a plurality of image detectors located at a corresponding plurality of positions relative to the plane of best imaging focus for producing a respective plurality of image signals;
- and
- b) determining a position of best focus by calculating the covariance between respective pairs of the image signals.
Dependencies are inferred from the claim text.