Patent attributes
There is provided a vehicular lamp that can be miniaturized by reducing signal lines connected to a vehicle main body. The vehicular lamp that is used for a vehicle includes a light source unit, and a signal line that connects the light source unit and a light source controlling unit for controlling lighting of the light source unit, in which the light source unit includes: a semiconductor light-emitting element; an optical member that irradiates light emitted from the semiconductor light-emitting element to the outside of the vehicle; a lighting controlling unit to which electric power is supplied from a vehicle main body and that control an electric current supplied to the semiconductor light-emitting element according to a voltage applied to the signal line by the light source controlling unit in order to control a light amount of the semiconductor light-emitting element; a current detecting resistor that is connected to the semiconductor light-emitting element in series; a current driving resistor that is connected to the signal line in series; and a comparator that sinks the current flowing into the current driving resistor and the same signal line as the signal line when a voltage is generated on the current detecting resistor by the current flowing into the semiconductor light-emitting element.
