| 摘要 |
PURPOSE:To eliminate the discrepancy between the start and end of winding when a shaft is wound with a mask and to omit the trouble of winding by removing a dynamic pressure generation groove part of a film coating the shaft by using a laser beam. CONSTITUTION:The entire surface of the rotary shaft 1 is coated with the film 16 which has a critical point smaller than the critical point of laser machining. A laser beam to be modulated which is emitted by a laser generation device 17 is deflected and scanned by a rotary polygon mirror 18, transmitted through image forming lenses 19a and 19b, and synchronized by a synchronism detection sensor 20 and while the rotary shaft 1 is rotated, the film 16 on the rotary shaft 1 except at the dynamic pressure generation groove part is removed with the laser beam to form the rotary shaft 1 coated with the film 16 only at parts which become grooves. Further, the rotary shaft 1 is dipped in etching liquid to stick plating material 21 on the part other than the film 16. Then the remaining film 16 is removed to manufacture the rotary shaft 1 which has the dynamic pressure generation grooves 22. |
