FOCUS DETECTOR, AUTOMATIC FOCUSING DEVICE AND CAMERA

Japanese Patent JP3630965

B2

PROBLEM TO BE SOLVED: To prevent the generation of hunting at the time of focusing a lens by making an area dividing means divide an area and selecting an area from among plural areas until information related to a distance obtained in the selected area becomes a prescribed state.
SOLUTION: An area sensor 201 is driven by a sensor driving circuit 202, storing operation in a photoelectric converter sensor is performed for detecting the foci in plural areas, the output of the sensor is taken in and focus information for every focus detecting area is calculated from the A/D value. A defocusing amount is calculated based on the result of focus detection and multifocus detection is performed. Grouping is performed based on the defocusing amount. A main object is decided from among the groups composing a screen. When the magnitude of absolute value of the defocusing amount of the main object is larger than the threshold value by comparing the defocusing amount of the main object with a defocus deciding threshold, a lens driving amount is calculated based on the defocusing amount of the main object, thereafter, the lens driving amount is communicated to a lens driving circuit 206 and a lens 213 is driven.

Keisuke Aoyama

JP36595997A

March 23, 2005

December 24, 1997

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Canon Inc

G03B7/28; G02B7/28; G03B13/36; (IPC1-7): G02B7/28; G03B13/36

JP9281386A
JP3164727A
JP7151950A
JP4154380A
JP6331883A

Minoru Nakamura

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