OPTICAL INFORMATION PROCESSOR

摘要

PURPOSE:To always secure the stable out-of-focus detection by fixing a part of a monolithic structure of the 1st and 2nd optical means to the side wall of a base member and also using members having approximately equal heat expansion coefficient to both optical means and the base member. CONSTITUTION:The members of approximately equal heat expansion coefficient are used to a base member 64 and the 1st and 2nd optical means 21 and 31 which are unified and fixed directly to the side wall of the member 64. This can suppress such a phenomenon where the parts forming both means 21 and 31 have shifts from the member 64 due to the heat expansion or contraction to produce the shift of an optical axis 30 despite generation of the temperature shift. As a result, the stable out-of-focus correction is possible with no shift of an optical axis against the temperature change.