Abstract: An LED drive device that drives and lights on an LED includes: a power conversion device that converts a voltage of a first power supply, and supplies the voltage to the LED; a second power supply having a voltage lower than a threshold voltage of the LED; a current generation unit that generates current using the voltage of the second power supply, and supplies generated current to an anode of the LED; and a ground-fault detection unit that determines that a ground fault does not occur at the anode of the LED when current does not flow from the current generation unit, and determines that the ground fault occurs at the anode of the LED when current flows from the current generation unit.

Abstract: An LED drive device that drives and lights on an LED includes: a power conversion device that converts a voltage of a first power supply, and supplies the voltage to the LED; a second power supply having a voltage lower than a threshold voltage of the LED; a current generation unit that generates current using the voltage of the second power supply, and supplies generated current to an anode of the LED; and a ground-fault detection unit that determines that a ground fault does not occur at the anode of the LED when current does not flow from the current generation unit, and determines that the ground fault occurs at the anode of the LED when current flows from the current generation unit.

Abstract: A lighting apparatus is provided which includes a drive section which applies electric current to a light source which is a semiconductor element emitting light with application of electric current, at least one heat sink which is mounted with the light source and transfers heat generated by the emission of the light source, and a temperature measurement section which is mounted to the heat sink and measures temperature of the heat sink which is used for estimating temperature of the light source. The light source and the drive section are mounted to the same heat sink or to the heat sinks which are thermally coupled to each other.

Abstract: An illuminant device designed to activate a light source selectively in a plurality of lighting modes. The illuminant device includes a plurality of circuit boards having thermal conductivity and a plurality of lighting circuits each of which is operable to activate the light source in a selected one of the lighting modes. The lighting circuits are mounted on the circuit boards so that when the light source is being activated, the circuit boards will be different in temperature thereof from each other due to heat generated in at least one of the lighting circuits which is activating the light source. The illuminant device also includes a connector which couples the lighting boards together to transfer the heat therebetween, thereby enhancing the dissipation of the heat.

Abstract: A lighting control apparatus for a vehicle is provided which works to diagnose a malfunction of a light source which includes a plurality of lighting devices such as LEDs and emits light outside the vehicle. The lighting control apparatus determines a state of the vehicle. When the light source is determined to be malfunctioning, the lighting control apparatus operates the light source in one of predetermined warning lighting modes which is selected based on the state of the vehicle. This attracts a vehicle user's attention to the malfunctioning light source.

Abstract: A vehicle headlamp assembly including a housing case and a lens cover forming a light chamber, a projection lens, a shade and a light source are arranged within the light chamber in that order along an optical axis of the headlamp assembly. A radiating member includes plate-shaped radiating fins vertically placed in the light chamber, for radiating heat energy generated by the light source to surrounding air. A plate is arranged at a right angle to the radiating fins in the light chamber, for controlling air-convection flow around the radiating fins.

Abstract: A light quantity control apparatus, which controls light quantity of a light of a vehicle, includes a traffic-jam-information obtaining unit obtaining traffic-jam-information including information on positions and on presence/absence of a traffic jam, a vehicle-position obtaining unit obtaining a position of a vehicle, a traffic-jam identifying unit identifying whether the vehicle is in a traffic jam based on the traffic-jam-information and the position of the vehicle, a traffic-jam-time light quantity control unit decreasing the light quantity compared with a normal time if the vehicle is in a traffic jam, an urban-district obtaining unit obtaining information on whether or not the vehicle is in an urban district or near an intersection, and an urban-district-traveling-time light quantity control unit decreasing the light quantity compared with a case where the vehicle is in an area other than urban districts and intersections if the vehicle is in the urban district or near an intersection.

Abstract: A vehicle lighting apparatus has a semiconductor light-emitting device, an optical unit for discharging light of the semiconductor light-emitting device toward an irradiated area, a driving circuit portion for supplying electric power to the semiconductor light-emitting device, and a heat radiating portion. The semiconductor light-emitting device is directly attached to the driving circuit portion. The optical unit, the driving circuit portion and the heat radiating portion are assembled together to form a lighting module.

Abstract: A lighting apparatus is provided which includes a drive section which applies electric current to a light source which is a semiconductor element emitting light with application of electric current, at least one heat sink which is mounted with the light source and transfers heat generated by the emission of the light source, and a temperature measurement section which is mounted to the heat sink and measures temperature of the heat sink which is used for estimating temperature of the light source. The light source and the drive section are mounted to the same heat sink or to the heat sinks which are thermally coupled to each other.

Abstract: A light quantity control apparatus, which controls light quantity of a light of a vehicle, includes a traffic-jam-information obtaining unit obtaining traffic-jam-information including information on positions and on presence/absence of a traffic jam, a vehicle-position obtaining unit obtaining a position of a vehicle, a traffic-jam identifying unit identifying whether the vehicle is in a traffic jam based on the traffic-jam-information and the position of the vehicle, a traffic-jam-time light quantity control unit decreasing the light quantity compared with a normal time if the vehicle is in a traffic jam, an urban-district obtaining unit obtaining information on whether or not the vehicle is in an urban district or near an intersection, and an urban-district-traveling-time light quantity control unit decreasing the light quantity compared with a case where the vehicle is in an area other than urban districts and intersections if the vehicle is in the urban district or near an intersection.

Abstract: A lighting control apparatus for a vehicle is provided which works to diagnose a malfunction of a light source which includes a plurality of lighting devices such as LEDs and emits light outside the vehicle. The lighting control apparatus determines a state of the vehicle. When the light source is determined to be malfunctioning, the lighting control apparatus operates the light source in one of predetermined warning lighting modes which is selected based on the state of the vehicle. This attracts a vehicle user's attention to the malfunctioning light source.

Abstract: An illuminant device designed to activate a light source selectively in a plurality of lighting modes. The illuminant device includes a plurality of circuit boards having thermal conductivity and a plurality of lighting circuits each of which is operable to activate the light source in a selected one of the lighting modes. The lighting circuits are mounted on the circuit boards so that when the light source is being activated, the circuit boards will be different in temperature thereof from each other due to heat generated in at least one of the lighting circuits which is activating the light source. The illuminant device also includes a connector which couples the lighting boards together to transfer the heat therebetween, thereby enhancing the dissipation of the heat.

Abstract: In a light chamber formed by a housing case and a lens cover placed at a front part (which is open) of the housing case in a headlamp assembly, a projection lens, a shade and a light source are arranged in order from the front side of the light chamber along an optical axis of the light source. A reflector for reflecting light emitted from the light source is placed at a position which is opposite to the light source. A radiating member is composed of radiating fins of a plate shape vertically placed in the light chamber, and radiates heat energy generated by the light source to surrounding air. A control plate surrounds and crosses at a right angle to the radiating fins in the light chamber. The control plate has a size of suppressing air-convection around the radiating fins and is fixed to the housing case through poles.