| 摘要 |
<p>PURPOSE:To easily detect the beginning of a desired part while a television or a monitor is being used without performing a complicated control operation by a method wherein changes in a frequency, a pressure, the quantity of light and the like from the outside are converted into a voltage or a pulse width at a set and a magnetic medium is moved by a desired amount. CONSTITUTION:When a dial 1 is turned, its direction of rotation is detected by using a signal 7 and transmitted to a motor drive circuit 4 and the direction of rotation of a motor is decided. When the dial 1 is turned, a pulse signal corresponding to a signal 8 is output and reshaped to a signal 9 by a waveformshaping circuit 2. The frequency of the signal 9 is changed by the turning speed of the dial 1. However, when an input average voltage to the drive circuit 4 is changed, the turning speed of the motor 5 is changed and a magnetic medium can be moved by a required amount. Thereby, the beginning of a desired part can be detected easily while a television or a monitor is being used without performing a complicated control operation.</p> |
