| 摘要 |
PROBLEM TO BE SOLVED: To facilitate maintenance and to simplify the configuration by eliminating mechanical contact part.SOLUTION: A fader device includes a first reflector that moves in accordance with the fader operation, a light source attached to a fixed part and from which the light for measurement impinges on the first reflector, a photodetector for detecting reflected light from the first reflector, a measurement section for measuring the optical path length from the light source to the photodetector, a sound volume control signal formation section for generating a sound volume control signal corresponding to the optical path length measured by the measurement section, and a sound volume control section for controlling the sound volume depending on the sound volume control signal. |
