OPTICAL DEFLECTOR UTILIZING WHICH FLUID BEARING

摘要

PURPOSE:To improve the performance of an optical deflector by using a fluid bearing provided with a device which lifts a revolving shaft in the direction for floating the same until the prescribed driving power in the axial direction of a mechanism for rotating the fluid bearing is generated and resets the same to the home position after the generation of the prescribed dynamic pressure. CONSTITUTION:A push rod 12 is first lifted together with a hard ball 10 by actuating first an actuator 14 for displacement. The rotating body (a) of the fluid bearing is then lifted as well and a gap is formed between a polyhedral reflecting mirror 6 and a body frame 8. The rotating body (a) maintains the prescribed rotation while said body is supported by the ball 10 and is kept floated by the dynamic pressure generated by the fluid fed into the frame 8 even if the revolving shaft 4 is rotated in this sate. The actuator 14 is reset to the home position when the dynamic pressure enough to supporting and rotating the body (a) is generated and the body (a) can continue smooth rotation in the prescribed position. The rod 12 descends together with the ball 10 to the home position. The rod 12 descends together with the ball 10 to the home position at the same instant and the rotation is continued even without the support by the actuator 14.