Abstract: In an automotive headlamp, a light-emitting module is configured such that a light-emitting element and a control circuit unit for controlling the lighting of the light-emitting element are structured integrally with each other. A control circuit unit in a position anterior to the light-emitting element in a lamp unit is located below a shade section so that the control circuit unit can be clear of the path of light used to form a low beam light distribution pattern of the light emitted by the light-emitting element. In this setting, the light-emitting element is so located that a main optical axis Ax2 is perpendicular respect to an optical axis Ax1 of the lamp unit and that a light-emitting portion of the light-emitting element protrudes higher than the control circuit unit in the direction of the main optical axis Ax2.

Abstract: In an automotive headlamp, a light-emitting module is configured such that a light-emitting element and a control circuit unit for controlling the lighting of the light-emitting element are structured integrally with each other. A control circuit unit in a position anterior to the light-emitting element in a lamp unit is located below a shade section so that the control circuit unit can be clear of the path of light used to form a low beam light distribution pattern of the light emitted by the light-emitting element. In this setting, the light-emitting element is so located that a main optical axis Ax2 is perpendicular respect to an optical axis Ax1 of the lamp unit and that a light-emitting portion of the light-emitting element protrudes higher than the control circuit unit in the direction of the main optical axis Ax2.

Abstract: A semiconductor light source lighting circuit is provided with: a switching regulator that generates a drive current of a semiconductor light source using a switching element; and a control circuit that controls ON/OFF of the switching element. The control circuit is provided with: a comparator that compares the drive current and a target value; a counter that counts a digital value in a count direction determined by a comparison result of the comparator; a digital-analog converter that converts the digital value into an analog signal; and a drive circuit that controls the ON/OFF of the switching element based on the analog signal. The counter counts the digital value at a speed determined by an ON/OFF cycle of the switching element.

Abstract: In an automotive headlamp, a light-emitting module is configured such that a light-emitting element and a control circuit unit for controlling the lighting of the light-emitting element are structured integrally with each other. A control circuit unit in a position anterior to the light-emitting element in a lamp unit is located below a shade section so that the control circuit unit can be clear of the path of light used to form a low beam light distribution pattern of the light emitted by the light-emitting element. In this setting, the light-emitting element is so located that a main optical axis Ax2 is perpendicular respect to an optical axis Ax1 of the lamp unit and that a light-emitting portion of the light-emitting element protrudes higher than the control circuit unit in the direction of the main optical axis Ax2.

Abstract: A semiconductor light source lighting circuit includes a voltage step-down unit configured to generate a drive voltage lower than an input voltage by turning on or off a first switching element in a voltage step-down mode, a voltage step-up unit configured to generate the drive voltage higher than the input voltage by turning on or off a second switching element in a voltage step-up mode, and a controller. The controller includes a charge pump unit configured to repeat charging from the drive voltage to a second capacitor and discharging from the charged second capacitor to the first capacitor in the voltage step-up mode, and a switch drive unit configured to apply a voltage higher than the voltage at the other end of the first switching element to the control terminal of the first switching element by using a voltage of the charged first capacitor.

Abstract: A circuit for lighting a semiconductor light source is provided. The circuit includes: a switching regulator including a switching element and configured to generate a drive current for the semiconductor light source using the switching element; and a control circuit configured to control on-off of the switching element such that the magnitude of the drive current comes close to a targeted value. The control circuit includes: a comparator configured to compare the magnitude of the drive current with the targeted value; an up/down counter configured to count a digital value in a counting-up direction or counting-down direction, based on a comparison result of the comparator; a digital-to-analog converter configured to convert the counted digital value into an analog signal; and a drive circuit configured to control on/off of the switching element based on the analog signal.

Abstract: A semiconductor light source lighting circuit includes a switching regulator that produces a drive current ILED with a switching element, and a control circuit that controls turning on and off of the switching element so that the magnitude of the drive current ILED approaches a target value. The control circuit includes an error comparator that compares the drive current ILED and the target value, an up/down counter that performs a counting operation, in which the control digital value is incremented or decremented based on the result of the comparison, a D/A converter that converts the control digital value into an analog duty ratio setting signal S4, and a drive circuit that controls the turning on and off of the switching element based on the signal S4. The up/down counter stops the counting operation when the switching regulator is brought into the inactive state.

Abstract: A semiconductor light source lighting circuit includes a voltage step-down unit configured to generate a drive voltage lower than an input voltage by turning on or off a first switching element in a voltage step-down mode, a voltage step-up unit configured to generate the drive voltage higher than the input voltage by turning on or off a second switching element in a voltage step-up mode, and a controller. The controller includes a charge pump unit configured to repeat charging from the drive voltage to a second capacitor and discharging from the charged second capacitor to the first capacitor in the voltage step-up mode, and a switch drive unit configured to apply a voltage higher than the voltage at the other end of the first switching element to the control terminal of the first switching element by using a voltage of the charged first capacitor.

Abstract: A vehicular lamp includes a light source, a cooling fan configured to cool the light source, a light source power supply module configured to drive the light source for emission of light, and a control module configured to execute an abnormal rotation detection of the cooling fan and to control the light source power supply module so that the quantity of light emitted from the light source is reduced in response to a detection of abnormal rotation.

Abstract: A vehicular rear panel having a new configuration is provided. The vehicular rear panel according to an aspect of the present disclosure is made of a resin material and disposed on the rear vehicle body part. The vehicular rear panel includes: a light source which is at least partially disposed in the inside of the vehicular rear panel, a circuit which is at least partially provided in the vehicular rear panel to supply electric power to the light source, and a light emitting unit configured to emit light source light to the rear of the vehicle.

Abstract: A semiconductor light source lighting circuit is provided with: a switching regulator that generates a drive current of a semiconductor light source using a switching element; and a control circuit that controls ON/OFF of the switching element. The control circuit is provided with: a comparator that compares the drive current and a target value; a counter that counts a digital value in a count direction determined by a comparison result of the comparator; a digital-analog converter that converts the digital value into an analog signal; and a drive circuit that controls the ON/OFF of the switching element based on the analog signal. The counter counts the digital value at a speed determined by an ON/OFF cycle of the switching element.

Abstract: A vehicular headlamp, wherein a light source unit for light distribution formation is accommodated inside a lamp chamber defined by a lamp body and a front cover, includes a metal heat transfer member that serves as a light source unit structural member; a light-emitting element that serves as a light source; a fan for cooling the light-emitting element provided inside the lamp chamber; and a lighting circuit that controls lighting of the light-emitting element. The light-emitting element, the fan, and the lighting circuit are each attached to the metal heat transfer member.

Abstract: A circuit for lighting a semiconductor light source is provided. The circuit includes: a switching regulator including a switching element and configured to generate a drive current for the semiconductor light source using the switching element; and a control circuit configured to control on-off of the switching element such that the magnitude of the drive current comes close to a targeted value. The control circuit includes: a comparator configured to compare the magnitude of the drive current with the targeted value; an up/down counter configured to count a digital value in a counting-up direction or counting-down direction, based on a comparison result of the comparator; a digital-to-analog converter configured to convert the counted digital value into an analog signal; and a drive circuit configured to control on/off of the switching element based on the analog signal.

Abstract: In an automotive headlamp, a light-emitting module is configured such that a light-emitting element and a control circuit unit for controlling the lighting of the light-emitting element are structured integrally with each other. A control circuit unit in a position anterior to the light-emitting element in a lamp unit is located below a shade section so that the control circuit unit can be clear of the path of light used to form a low beam light distribution pattern of the light emitted by the light-emitting element. In this setting, the light-emitting element is so located that a main optical axis Ax2 is perpendicular respect to an optical axis Ax1 of the lamp unit and that a light-emitting portion of the light-emitting element protrudes higher than the control circuit unit in the direction of the main optical axis Ax2.

Abstract: A semiconductor light source lighting circuit includes a switching regulator that produces a drive current ILED with a switching element, and a control circuit that controls turning on and off of the switching element so that the magnitude of the drive current ILED approaches a target value. The control circuit includes an error comparator that compares the drive current ILED and the target value, an up/down counter that performs a counting operation, in which the control digital value is incremented or decremented based on the result of the comparison, a D/A converter that converts the control digital value into an analog duty ratio setting signal S4, and a drive circuit that controls the turning on and off of the switching element based on the signal S4. The up/down counter stops the counting operation when the switching regulator is brought into the inactive state.

Abstract: In a process in which a control signal having a low level is output from an ON/OFF control circuit to series regulators connected to LEDs serving as lighting targets to turn ON the LEDs in accordance with digital communication information, the ON/OFF control circuit calculates a specified current value to be supplied to the LEDs serving as the lighting targets and compares the specified current value with a detected current value which is detected by a current detecting circuit, and outputs a stop signal to a control circuit on the assumption that a current flows without the series regulators with grounding generated on a cathode side of any of LEDs when the detected current value is greater than the specified current value. When the control circuit turns OFF an NMOS transistor in response to the stop signal, an operation of a switching regulator is stopped.

Abstract: A light emitting device includes multiple light units each of which includes a semiconductor light source, and a current supply control means for controlling supply of current to the semiconductor light source. A control unit includes a control signal generation means for generating and providing a control signal. The light emitting device also includes switching means for controlling feeding from a DC power source to a corresponding one of the light units in response to the control signal. Each of the switching means is coupled to a corresponding one of the light units through a feed line.

Abstract: A light emitting device drive circuit includes: a power conversion unit for receiving an input electric power and performing an electric power conversion on the input electric power in accordance with a control signal so as to generate the predetermined output current; a current detection unit for detecting an output current IL of the power conversion unit; a temperature detection unit for detecting a case internal temperature TD, which is an interior temperature of a case for accommodating the light emitting device drive circuit; a regulation unit being operable to a) detect whether a temperature TL of the light emitting device has reached a first predetermined temperature TLmax based on TD, IL, and a temperature rise coefficient ? relative to IL, the temperature rise coefficient ? being set in advance so that TL satisfies a relationship of TL=TD+?·IL, and b) generate a regulation signal for reducing a predetermined output current IL0 so that TL does not exceed TLmax in the event that a result of the detecti

Abstract: A vehicular headlamp, wherein a light source unit for light distribution formation is accommodated inside a lamp chamber defined by a lamp body and a front cover, includes a metal heat transfer member that serves as a light source unit structural member; a light-emitting element that serves as a light source; a fan for cooling the light-emitting element provided inside the lamp chamber; and a lighting circuit that controls lighting of the light-emitting element. The light-emitting element, the fan, and the lighting circuit are each attached to the metal heat transfer member.

Abstract: When the level at an input terminal goes low upon the reception of a signal to dim an LED, a PNP transistor is rendered on and a voltage at the positive input terminal of an operational amplifier is raised, in accordance with a time constant that is defined by a resistor and a capacitor. In accordance with the increase in this voltage, a source current is supplied from the operational amplifier to a current detection terminal, and as the value of the source current is gradually increased, a current flowing across the shunt resistor of the switching regulator is gradually reduced. Further, the light emission level of the LED is gradually lowered from the fully lighted state to the 70% lighted state, and there is, for the LED, a light quantity change of about 30% in ten seconds.