| 摘要 |
PURPOSE:To automatically control volume balance on right and left sides by reading proper right and left balance control voltages after a microcomputer calculates the right and left distances of a main body equipment from the position of an operator according to time difference between light emission and light reception utilizing light by operating a remote control unit. CONSTITUTION:A microcomputer 15 for control transmits the prescribed number of pulse signals through a first switching circuit 13 to a second light emission part 6 and calculates a distance L1 by calculating time from the light emission of the second light emission part to the light reception of a second light reception part. Continuously, a distance L2 is calculated after switching first and second switching circuits 13 and 14 from the side of the second light emission/ reception part to the side of a third light emission/reception part. On the other hand, since a distance L3 between the second light emission/reception part and the third light emission/reception part is an already known value decided according to the structure, a triangle having the L1-L3 as sides is specified. Then, a balance control signal corresponding to the differential distance is read out from a second storage part 18 and transmitted to a D/A conversion part 19, and the digital signal is converted to an analog signal. |
