Patent ID: 7950028

Claim:
A disk apparatus comprising: a movable member equipped with an optical pickup at a position facing a disk surface and adapted to move around the base end portion thereof between a first position where said optical pickup faces said disk surface and a second position retracted from said first position where said optical pickup is kept away from said disk surface; a chassis as a fixed member to which the base end portion of said movable member is attached; a clamp mechanism adapted to perform a clamping operation for clamping a disk carried in a position facing said optical pickup in conjunction with the movement of said movable member from said second to first position and an unclamping operation for unclamping the disk in conjunction with the movement of said movable member from said first to second position; a cam mechanism for moving said movable member between said first and second positions, said cam mechanism including a shift lever connected to the free end portion of said movable member via an elastic body exhibiting a vibration damping effect and a cam main body for allowing said movable member to follow the up-and-down movement of said shift lever and thereby to move between said first and second positions; a weight attached to said movable member to exhibit a vibration control effect for said movable member; positioning means having: a protrusion provided on said shift lever; a stepped engaging surface for supporting said protrusion thereon to position the free end portion of said movable member; and a guide mechanism for displacing said shift lever to draw said protrusion onto said engaging surface, said guide mechanism including a movable slant surface provided on said shift lever and a fixed slant surface provided on said chassis on which said movable slant surface is slidable; and anti-positioning means formed by said cam main body to release a positioning state of said movable member by said positioning means by displacing said shift lever around the position of said elastic body while deforming said elastic body with said movable member being in said first position to separate said movable slant surface from said fixed slant surface and by displacing said protrusion around the position of said elastic body to disengage said protrusion from said engaging surface.