| 摘要 |
PURPOSE:To improve the durability and to facilitate the speed control while maintaining the scanning accuracy at a constant level by sticking thin mirror pieces on the peripheral surfaces of a holder. CONSTITUTION:The holder 11 has a hollow part 14 for weight reduction and many discontinuous through holes 15 which penetrate the holder to the hollow part 14 from outside are formed. The diameter (d) of the through holes 15 is so selected that the surface area of the internal wall is larger than the opening area. When the respective mirror pieces 21 are stuck on the peripheral surfaces 12 of the holder 11 by using an adhesive, the respective mirror pieces 21 are pressed against the holder peripheral surfaces 12 and then the adhesive is pressed against the holder peripheral surface 12 by the respective mirror pieces 21, so that a part of the adhesive enters the through holes 15. The adhesive become well flowable because of the through holes 15 and while the adhesive is spread uniformly on the peripheral surfaces 12 of the holder 11, the respective mirror pieces 21 are adhered. Consequently, the respective mirror pieces 21 even when made thin are stuck flatly on the holder peripheral surfaces 12. |
