| 摘要 |
PROBLEM TO BE SOLVED: To minimize the increase of current consumption, to reduce a transient responding time, to accelerate modulation and to obtain output light of small pulse waveform distortion even in the LED of a large internal capacity. SOLUTION: By using the property of the LED being an element capable of providing optical output proportional to the forward current by the rapid flow of current when a voltage pulse Vd applied to the intrinsic diode of an electric equivalent model amounts to a value very close to a peak value, a rectangular voltage pulse having large current driving ability by low output impedance or a binary voltage pulse at a high level boosting voltage just after starting and returning it to prescribed voltage a fixed time later is supplied to a directly connected LED load. The low level of a pulse is DC-biased in the range of voltage capable of keeping the extinction ratio of an LED output signal required for the request of a system.
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