Patent ID: 6239912
Filing Date: 2001-05-29
Classification: G02B

Abstract:
A focal point detection apparatus comprising:a view field mask disposed in the vicinity of a prearranged imaging plane of a photographing lens and provided with a plurality of view field apertures corresponding to a plurality of focal point detection areas;a condenser lens provided with a plurality of lens units to respectively condense light fluxes transmitted by said plurality of view field apertures of said view field mask; anda re-imaging optical system provided with a plurality of re-imaging lens units to divide a light flux transmitted by each of said plurality of view field apertures into a pair of light fluxes and to transmit said pairs of light fluxes to different areas of the exit pupil of said photographing lens and to form images of said plurality of view field apertures on a light receiving element,wherein said plurality of lens units are arranged such that the light fluxes transmitted by said plurality of view field apertures cross each other between said condenser lens and said re-imaging optical system.