초록

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.

대표청구항 ▼

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 fi

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.