Focusing detecting method

Abstract

Abstract PURPOSE:To enhance focusing accuracy by simultaneously sample-holding the outputs of the multiple photodetectors of plural photodetectors disposed in the positions conjugated with the focal plane of an optical system, A/D-converting the values of every photodetector in parallel and operating these. CONSTITUTION:A part of the image of a subject is projected to the photodetectors 3A, 3B which are disposed at an equal distane before and behind the intended focal plane of a photographic optical system. The outputs of all the photodetectors of the respective photodetectors are held in sample-holding circuits 18A1-18An, 18B1- 18Bn. Then, the values held in the circuits 18A1-18An are parallelly A/D-converted by a D/A converter 20 and comparators 191-19n, and are stored in digital memories 221-22n. Their evaluation values are determined by a central processing unit 5. Thereafter, from the values held in the circuits 18B1-18Bn, evaluation values are determined by the operation similar to the above, and the focus detection signal is obtained by comparing both evaluation values.

Inventors

• 👤 Takeomi Suzuki
• 👤 Masahiro Aoki
• 👤 Kenichi Oikami
• 👤 Masatoshi Ida

Bibliographic Details