| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the fluctuation of a light reception level due to the deviation of an optical axis in a system for optically transmitting a signal to a fixing part from a rotation part rotatable with respect to the fixing part. <P>SOLUTION: An LED circuit (101) faces a photodiode (106) in a mechanism where a rotation part (122) is rotatably supported with respect to a fixing part (121). In a measurement mode, a control part (134) of the rotation part (122) drives the LED circuit (101) with a fixed current at a predetermined rotation angle position. A control part (153) of the fixing part (121) measures a light reception level at each rotation angle position on the basis of the output of the photodiode (106), and stores the angle dependence in an EEPROM (154). When rotating, the rotation part (122) transmits a rotation angle position to the fixing part (121). The control part (153) of the fixing part (121) controls the amplification factor of an amplifier circuit (150) for amplifying the output of the photodiode (106) to be the amplification factor corresponding to the rotation angle position. <P>COPYRIGHT: (C)2013,JPO&INPIT |
