Patent ID: 7616879

Claim:
An optical apparatus having an auto-focus function through a pupil slicing focus detection by a through the taking lens phase difference detection comprising: an optical deflector for splitting an image light of an object that passes an exit pupil of an image-taking optical system into a first polarized light component and a second polarized light component and for deflecting two luminous fluxes comprising of the first polarized light component with respect to the other in a deflection direction; a photoelectric conversion element for receiving the image light from the optical deflector so that at least two images are formed on different areas of the photoelectric conversion element; a focusing glass; a polarization beam splitter for reflecting the second polarized light component to the focusing glass and for transmitting the first polarized light component to the photoelectric conversion element; and a detector for detecting a phase difference of the at least two images formed on different areas of the photoelectric conversion element thereby detecting a focusing state of the image-taking optical system, wherein the photoelectric conversion element is an image-pickup device configured to photograph the image light of the object formed by the image-taking optical system and to generate an output signal for the detector.