| 摘要 |
PURPOSE:To make a rotational angle detection part compact and to improve a dynamic characteristic by fixing the various two kinds of metal to the outer periphery of the rotary shaft of a mirror in a circumferential direction while being abutted and joined, and facing a non-contact eddy current displacement gauge to the joining line part of the both various kinds of metal. CONSTITUTION:One end of a torsion bar 15 is fixed to an output shaft 16 of a differential accelerating mechanism 4 and the other end is fixed to a control member 17 screwed to a main body 1 respectively. On the outer periphery of an output shaft 3 of a mirror 2 linked to the output shaft 16 of the differential accelerating mechanism 4, the various two kinds of metal such as first metal 18 and second metal 19 is abutted, joined and fixed in the circumferential direction. Further, while being faced to a joining line 20 of the both metal 18 and 19, a sensor head 22 of a non-contact eddy current displacement gauge 21 is provided. The backlash of a transmission system in the differential accelerating mechanism 4 is absorbed by the torsion bar 15 and the rotational angle of the mirror 2 is detected by the non-contact eddy current displacement gauge 21. |
