Patent ID: 6222687
Filing Date: 2001-04-24
Classification: G02B,G11B

Abstract:
An object lens supporting unit used for supporting an object lens for converging laser beam irradiated from a laser source in a constant direction, which comprises a supporting frame for supporting the object lens, a base member for mounting said supporting frame thereon, an adjusting mechanism for adjusting said supporting frame with the supporting frame universally tilted to the base member, said adjusting mechanism comprising:a pedestal portion formed on a top surface of the base member;a plurality of protrudent portions protruded from a bottom surface of said supporting frame, which are in contact with the pedestal portion, and which are capable of freely sliding along the pedestal portion; andholding means for limiting the motion of the protrudent portions within a predetermined sliding range of said protrudent portion;said pedestal portion having a curved surface formed along a surface of a supposed revolution body, said supposed revolution body being formed by rotation of an ellipse around a minor axis thereof, said supposed revolution body being further inscribed to a supposed spherical surface formed around a central point, said central point being served by a principal point of said object lens supported by said supporting frame;said protrudent portions being arranged so as to be in contact with said curved surface at positions which correspond to an area of said supposed revolution body inscribed to said supposed spherical surface.