| 摘要 |
PURPOSE:To shorten the rising and breaking time of a current by providing a switching circuit for completely varying a current flowing to a light emitting element in response to a binary signal, and a prebiasing circuit for applying a voltage of the degree not exceeding a light emitting threshold voltage to the light emitting element. CONSTITUTION:A switching circuit 6 conducts and cuts off the current flowing to a LED 5 in response to an input binary signal. Therefore the current flowing to the LED 5 is intermittently interrupted, and the LED 5 repeats emitting of a light and distinction of the light in response to the input binary signal. Since a voltage of the degree not exceeding a light emitting threshold voltage is applied to the LED 5 by a prebiasing circuit 7, the voltage applied to the LED 5 is rapidly arrived at a predetermined voltage. Thus, the rising and breaking time of the current flowing to the LED 5 are shortened. |
