Patent ID: 8536797
Filing Date: 2013-09-17
Classification: H02M,H05B,Y02B

Abstract:
1. A semiconductor light source apparatus, comprising: a semiconductor light emitting device; a power supply circuit that supplies operating power; a drive circuit including (i) a passive element that accumulates and discharges the power from the power supply circuit, (ii) a charging path that supplies and accumulates the power from the power supply circuit in the passive element, (iii) a discharging path that discharges the power accumulated in the passive element by causing the semiconductor light emitting device to emit light, and (iv) a plurality of switching elements that switch between the charging path and the discharging path, and thereby intermittently drive the semiconductor light emitting device; a constant current switch controller that (A) detects a voltage applied to a path when each one of the charging path and the discharging path is selected and (B) switches the plurality of switching elements by calculating a switching duty ratio of the plurality of switching elements such that a current flowing through the passive element is maintained at a constant value in accordance with detection results; and a duty monitoring unit that adjusts a voltage value of the power supplied by the power supply circuit in accordance with the switching duty ratio calculated by the constant current switch controller.