DYNAMIC PRESSURE AIR BEARING TYPE OPTICAL DEFLECTOR

摘要

PROBLEM TO BE SOLVED: To provide a dynamic pressure air bearing type optical deflector which is capable of exhibiting the highest possible performance and can suppress the whistling noise by a rotary polyhedral mirror and suppress the generation of noise even at the use form frequently repeating the start and the stop. SOLUTION: This dynamic pressure air bearing type optical deflector has a stationary shaft erected on a case and a revolving shaft freely rotatably supported by a radial dynamic pressure air bearing consisting of herringbone grooves and other dynamic pressure generating parts at the outer periphery of the stationary shaft, houses rotary polyhedral mirror rotating integrally with the revolving shaft and other rotor parts into the case hermetically closed by a cover member and has a pump mechanism which decompresses or evacuates the inside of the case by discharging the air in the case to the outside of the case. The deflector is constituted by lowering the whistling noise generated by the rotary polyhedral mirror, etc., by rotary driving the rotor parts at <=prescribed rotary speed lower than the use rotary speed until the pressure in the case arrives at prescribed pressure.