| 摘要 |
<p>PURPOSE:To obtain a light-emitting-element driving circuit, which makes the fall characteristic of the element steep without decreasing light emitting efficiency, by providing a circuit in which the light emitting element and a diode are connected in reverse parallel, connecting said circuit to a transistor circuit which is formed in a complementary pattern, and alternately supply current to the light emitting element and the diode. CONSTITUTION:When a pulse voltage Ei shows a state of Ei=0, a transistor 5 is turned OFF, but a transistor 6 is turned ON by a bias voltage Eb2. A voltage E2 causes a current ID to flow through a diode 7 and the transistor 6. At this time the transistor 5 is in an OFF state, but a current IL does not become zero quickly but tends to flow continuously. Since the current ID also flows through the diode 7, a forward voltage drop is generated in the diode 7. The forward current causes a charging current to flow through a light emitting element 1 in the reverse direction by way of a parasitic capacitor. Therefore the current IL cannot continue to flow but reaches zero rapidly.</p> |
