| 摘要 |
PROBLEM TO BE SOLVED: To provide a light emitting element drive circuit which is simple in structure, capable of shortening a current waveform rise time of a transistor connected to a light emitting element, and high in noise resistance. SOLUTION: A transistor N2 is connected to a light emitting element 1 in series, and a connection contact point between the source of a current switching transistor N8 and the drain of a transistor N9 is connected to the gate of the transistor N2. A source follower composed of transistors N5 and N6 is connected in a preceding stage of a transistor 8, and the source follower is lessened in output impedance, by which the gate of the transistor N2 is lessened in input impedance, and an N2 gate capacitance is lessened in charging time constant. |
