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US 4,059,758 AGranted
Autofocus system
AssigneeHoneywell Inc.
InventorDennis J. Wilwerding
Life of this patent
Estimating the term…
Abstract
An automatic single focus system of the spatial image correlation type uses two scans to position the primary lens. During a first scan, the amplitude of the major extremum in the correlation signal is stored. During the second scan, this stored amplitude is used to pick out the point of best focus.
Claims13
An optical system comprising:
- lens means for providing a primary image of an object;
- scanning means for providing first and second scans of an auxiliary image of the object;
- range sensing means for receiving the auxiliary image and providing a correlation signal having a major extremum during the first scan;
- position sensing means for providing a position signal indicative of the position of the scanning means;
- storing means for storing the value of the position signal when the major extremum occurs during the first scan;
- lens drive means for moving the lens means in a predetermined relationship with the scanning means during the second scan;
- and
- focus control means for halting motion of the lens means during the second scan when the position signal attains the value stored by the storing means.
5 more elements
In a camera having taking lens means, an automatic focus system for positioning the taking lens means prior to taking of a photograph, the automatic focus system comprising:
- scanning means for providing first and second scans;
- range sensing means for producing an output signal when the scanning means is in a position corresponding to a desired range during the first scan;
- position sensing means for providing a position signal indicative of the position of the scanning means;
- storing means for storing the value of the position signal when the range sensing means produces the output signal during the first scan;
- lens drive means for moving the taking lens means in a predetermined relationship with the scanning means during the second scan;
- and
- focus control means for halting motion of the taking lens means during the second scan when the position signal attains the value stored by the storing means.
4 more elements
Dependencies are inferred from the claim text.