Focus detecting device

Abstract

Abstract PURPOSE:To reduce the thickness of a camera main body and to make the camera body compact by performing setting operation so that reference part luminous flux is reflected by a reflecting surface close to a turning shaft at the downward movement position of a reflecting member and reference part luminous flux is reflected by a reflecting surface distant from the turning shaft. CONSTITUTION:The length la between the intersection H0 of a mirror 14 with an optical axis 10 and an upper end part (on the side of the turning shaft 14a) is limited by a main mirror 12. When the main mirror 12 is moved forth so as to increase the length la, the camera body 30 increases in thickness and can not be made compact. For the purpose, the reference part luminous flux (a) is reflected by the reflecting surface close to the turning shaft 14a of a submirror 14 and the large reflecting part luminous flux (b) is reflected by the reflecting surface distant from the turning shaft 14a of the submirror 14, so pieces (a) and (b) of luminous flux for focusing are reflected effectively without making the submirror 14 by moving the main mirror 12 forth.

Inventors

• 👤 Toshihiko Karasaki
• 👤 敏彦 唐崎

Bibliographic Details