Patent ID: 8704461
Filing Date: 2014-04-22
Classification: H05B,Y02B

Abstract:
1. A vehicle lighting device in which a switching regulator, a voltage detection resistor, and a light emitting element are sequentially connected in series between an input power supply and a ground terminal, the vehicle lighting device comprising a switching controller controls a current that is supplied to the voltage detection resistor from the switching regulator and, controls a current that is supplied to the light emitting element, in accordance with a difference obtained by comparing a voltage that is detected from the voltage detection resistor and a reference voltage that is taken out from a voltage dividing resistor that is connected between a constant voltage source and the ground terminal, the vehicle lighting device further comprising: between the input power supply and the ground terminal, a first current control circuit adapted to supply a current that decreases a voltage of the voltage dividing resistor, to the voltage dividing resistor, in a case where a voltage of the input power supply decreases to a preset value or less; and between the constant voltage source and the ground terminal, a second current control circuit adapted to supply a current that decreases a voltage of the voltage dividing resistor, to the voltage dividing resistor, in a case where a temperature that is detected by means of a temperature detection element increases to a preset value or more.