| 摘要 |
PROBLEM TO BE SOLVED: To reduce power loss and heat generation in a current drive circuit of a light-emitting element.SOLUTION: A light-emitting element drive device drives N (N is an integer of 1 or more) light-emitting element groups, and includes a drive voltage generation circuit including a lowest voltage detection circuit as a feedback path, N current drive circuits, and N or less than N voltage adjustment circuits. Each of the N light-emitting element groups includes one or more light-emitting elements. The drive voltage generation circuit feeds a predetermined voltage of a voltage source to the N light-emitting element groups. The N current drive circuits drive the N light-emitting element groups with current through the voltage adjustment circuits. Among the N current drive circuits connected to the lowest voltage detection circuit, a current drive circuit with the lowest voltage across the current drive circuit is selected as the feedback path of the drive voltage generation circuit. Even if a voltage across each of the light-emitting element groups is different from each other, a voltage across each current drive circuit is reduced to a voltage equal to or greater than the minimum voltage at which each current drive circuit can run by the voltage adjustment circuits. |
