| 摘要 |
PURPOSE:To maintain with a high accuracy a distance extending from a stopper member to a recording medium by attaching the stopper member for controlling the maximum displacement quantity in the optical axis direction of an objective lens, to a bearing block. CONSTITUTION:A detaining member 4 is attached to a lens holder 3 in the surface being orthogonal to an optical axis of an objective lens 2. Also, a bearing block 7 is installed to one side of an optical head body 6. A guide shaft 9 is inserted through this block 7 and by the shaft 9, the body 6 is supported so as to be freely slidable in the diameter direction of a recording medium 1. Also, a stopper member 10 having an upper limit stopper 10a and a lower limit stopper 10b extending in the surface being orthogonal to the optical axis direction of a lens is formed as one body in the block 7. The stoppers 10a, 10b are constituted so that in case the holder 3 has been displaced abnormally greatly, the member 4 abuts on the stopper 10a or 10b. By forming in this way, the stoppers 10a, 10b can be positioned with a high accuracy against the shaft 9, and a distance extending from the member 10 to the medium 1 can be maintained with a high accuracy. |
