| 摘要 |
<p>PURPOSE:To compensate the variation in transmission characteristic freely of the limitation by modulation system by reading the variation component of the transmission characteristic associated with the rotation of a coaxial rotary body in an optical manner, and controlling a compensation circuit with an output from said reading. CONSTITUTION:While the rotary part of a rotary coupler 7 rotates, a light beam is projected on the optical pattern of a sheet 9 to be detected by a light source 10 through a lens 12A, and a reflecting light beam is received by a light receiver 11 via a lens 12B. Thus detected signal is transmitted to a control terminal 23 via an amplifier 13. A variable gain amplifier 14 is controlled by means of this detection signal to smoothen the variation in signals from the rotary coupler 7 and to output them to an output terminal 25.</p> |
