Patent ID: 7283737
Filing Date: 2007-10-16
Classification: G02B

Abstract:
1. A focus detecting apparatus, comprising: a secondary image forming optical system for forming a plurality of light quantity distributions related to an object image from light beams that passed through different pupil regions of an objective lens; and a photoelectric transducer including a plurality of pixel lines each having a plurality of pixels aligned in a predetermined direction, each of the plurality of light quantity distributions being formed on a corresponding pixel line of the plurality of pixel lines, wherein the secondary image forming optical system comprises: a deflecting member comprising a first prism member for deflecting at least one of the plurality of light quantity distributions in a direction perpendicular to the predetermined direction; and a correcting member comprising a second prism member for deflecting at least one of the plurality of light quantity distributions in a direction opposite to the deflection direction of the deflecting member and for correcting displacement of an image formation position in the deflection direction of the deflecting member due to chromatic dispersion of the deflecting member, and wherein the first prism member and the second prism member are made of materials different from each other in Abbe's number.