| 摘要 |
PURPOSE:To execute focus control and tracking control with high accuracy by connecting the end of a supporting means to an optical system holder through a supporting shaft and a bearing and connecting another end rotatably to a base stand. CONSTITUTION:An objective lens holder 2 consists of a columnar member wound with a coil 18 on the outer peripheral part, an objective lens 1 and an objective lens holding member having two cylindrical bearings 3, 4 provided in the direction perpendicular (X direction) to the direction of optical axis (Y direction) of the lens 1. The first supporting means that controls movement in X direction of the holder 2 is constituted to shafts 5, 6 and bearings 3, 4, and guides 7, 8 and 9, 10 are provided on the end of shafts 5, 6, and the end of each of wires 11-14 that act as the second supporting means is fixed appropriately to a part of guides 7-10, and another end of each wire is fixed to a part of supporting shafts of turning means 19-22 consisting of supporting shafts and bearings provided on a base stand 23. Movement in X, Y directions is made by the electromagnetic force of current applied to coils 16, 18 and magnetic fields made by permanent magnets 15, 17. |
