| 摘要 |
PURPOSE:To enable the changeover of the scale and sound volume.of a sound source without contact by varying the frequency or sound volume of the sound source according to the distance from an object obtd. by measurement. CONSTITUTION:The distance between the object and the sound source device 15 is optically reduced and is obtd. as a distance (d). The distance is substd. as a ratio of currents I1, I2 with a voltage by a different amplifier 2. A voltage- to-frequency converter 3 oscillates the frequency meeting the voltage. As a result, the sounds of the pitch meeting the distance is oscillated by approaching and being apart of the object to and from the sound source device 15. Then, the measurement of the distance is executed without contact and, therefore, the scale and sound volume of the sound source are freely changed over even without contact or proximity to or with the sound source device 15. The free selection of the place for installation of the sound source device is consequently possible and the free form of performance is possible when the sound source device is used as an electronic musical instrument. |
