| 摘要 |
PURPOSE:To reduce the power consumption, by actuating a light emitting diode for display of a receiving channel with a low level of luminance during a receiving mode and displaying the switched channel at a high level of luminance for a certain period of time when the channel is switched. CONSTITUTION:When a channel CHA, for example, is received, a light emitting diode LED11 is turned on to display that the channel CHA is received. In this case, a transistor TR18 is turned off, and the LED11 is connected with resistances 15 and 19 and driven at a low level of luminance. If the reception of channel CHB is desired under such conditions, a CH up-switch 1 is pushed. Thus a counter circuit 3 counts up 1 and delivers it to a decoder circuit 4. The circuit 4 decodes the output of the circuit 3 and turns off and on the LED11 and LED12 respectively. In this case, a pulse (a) is fed to a pulse generating circuit 17 via the circuit 3. Then a pulse signal (b) of a certain duration is delivered from the circuit 17 to turn on the TR18 and to short-circuit the resistance 19. Thus an LED12 is driven with a high level of luminance. When the signal (b) is set zero, the TR18 is turned off. Then the LED12 is driven with a low level of luminance. |
