Abstract: A light emission drive device includes a current supply unit, which supplies driving current to a light emitting element, which performs light emission of a first function and light emission of a second function, a controller, which controls the driving current so as to have a current value depending on a dimming voltage, and a dimming voltage generator, which generates the dimming voltage. The dimming voltage generator applies a voltage, obtained according to the resistance value of a connected external resistor, to a voltage buffer, and controls the output voltage of the voltage buffer according to whether to perform light emission of any one of the first function and the second function so as to generate the dimming voltage.

Abstract: Provided is a lighting circuit that drives a first light source and a second light source connected in series with each other. A bypass switch is provided in parallel with the second light source. A constant current circuit is connected in parallel with one of the first light source and the second light source. A drive circuit supplies a drive current to a serially-connected circuit of the first light source and the second light source.

Abstract: A lighting circuit which lights a semiconductor light source, the lighting circuit includes a drive circuit configured to receive a PWM signal from a controller, to generate a drive current to the semiconductor light source, and to switch the drive current according to the PWM signal. When a non-input state of the PWM signal exceeds a predetermined time, the lighting circuit is configured to assert an abnormality detection signal and to output the abnormality detection signal to the controller.

Abstract: A light source includes a first light emitting unit, which performs light emission of a first function, and a second light emitting unit, which performs light emission of a second function and has the maximum lighting voltage lower than the forward voltage of the first light emitting unit, the first light emitting unit and the second light emitting unit being connected in parallel to each other. A lighting circuit includes a current supply unit, which supplies driving current to the light source, a controller, which performs stabilization control of the driving current from the current supply unit, a switch element, which is provided to disconnect a current path portion, which is the current path of the second light emitting unit and is parallel to the current path of the first light emitting unit, and a selector, which connects the current path of the second light emitting unit by the switch element when light emission of the second function is performed.

Abstract: A light emission drive device includes a current supply unit, which supplies driving current to a light emitting element, which performs light emission of a first function and light emission of a second function, a controller, which controls the driving current so as to have a current value depending on a dimming voltage, and a dimming voltage generator, which generates the dimming voltage. The dimming voltage generator applies a voltage, obtained according to the resistance value of a connected external resistor, to a voltage buffer, and controls the output voltage of the voltage buffer according to whether to perform light emission of any one of the first function and the second function so as to generate the dimming voltage.

Abstract: A drive circuit supplies a drive current to a second light source. A dummy load circuit is connected to a control line to which a lighting control signal, which instructs the second light source 304 to be turned on and off, is input, and the dummy load circuit sinks a dummy load current IDUMMYLOAD which decreases as a temperature increases.

Abstract: A drive circuit supplies a drive current to a second light source. A dummy load circuit is connected to a control line to which a lighting control signal, which instructs the second light source 304 to be turned on and off, is input, and the dummy load circuit sinks a dummy load current IDUMMYLOAD which decreases as a temperature increases.

Abstract: A lighting circuit is configured to supply a driving current to a first light source and a second light source. The light circuit includes a conversion unit which receives a first voltage for the first light source and a second voltage for the second light source via a common input terminal, performs voltage conversion on the first voltage or the second voltage and supplies the driving current, a control unit which controls a current value of the driving current output from the conversion unit, a first switch which selects whether to supply the driving current to the first light source by a first signal based on the first voltage, a signal generation unit which receives the first voltage and the second voltage and generates a second signal, and a second switch which selects whether to supply the driving current to the second light source by the second signal.

Abstract: Provided is a lighting circuit that drives a first light source and a second light source connected in series with each other. A bypass switch is provided in parallel with the second light source. A constant current circuit is connected in parallel with one of the first light source and the second light source. A drive circuit supplies a drive current to a serially-connected circuit of the first light source and the second light source.

Abstract: A lighting circuit which lights a semiconductor light source, the lighting circuit includes a drive circuit configured to receive a PWM signal from a controller, to generate a drive current to the semiconductor light source, and to switch the drive current according to the PWM signal. When a non-input state of the PWM signal exceeds a predetermined time, the lighting circuit is configured to assert an abnormality detection signal and to output the abnormality detection signal to the controller.

Abstract: A lighting circuit is configured to supply a driving current to a first light source and a second light source. The light circuit includes a conversion unit which receives a first voltage for the first light source and a second voltage for the second light source via a common input terminal, performs voltage conversion on the first voltage or the second voltage and supplies the driving current, a control unit which controls a current value of the driving current output from the conversion unit, a first switch which selects whether to supply the driving current to the first light source by a first signal based on the first voltage, a signal generation unit which receives the first voltage and the second voltage and generates a second signal, and a second switch which selects whether to supply the driving current to the second light source by the second signal.

Abstract: A semiconductor light source lighting circuit includes a transistor and a current detection resistor provided in series in a semiconductor light source current supply path, a control circuit for controlling the transistor so as to decrease any difference between the voltage occurring at the current detection resistor and a reference voltage, and a bypass resistor to establish a bypass path for the current supplied to the semiconductor light source, where a first end of the bypass path is located at a connection node between the transistor and the semiconductor light source.

Abstract: A lighting circuit includes: a countercurrent prevention unit including a first control terminal and a second control terminal, the countercurrent prevention unit transmitting a first current or a second current; and a current controller including: a common terminal connected to the first control terminal and the second control terminal; and a switching terminal connected to the first control terminal, the current controller providing a first driving current or a second driving current from the common terminal to the light source. The countercurrent prevention unit further includes: a first rectifier, wherein voltage at the first control terminal is provided to the switching terminal through the first rectifier; a first P-FET provided between the first control terminal and the common terminal; a second P-FET provided between the second control terminal and the common terminal; and a second rectifier provided between the second P-PET and the common terminal.

Abstract: A vehicle lamp lighting control device includes: a current control unit which is of a non-insulation type and supplies a supply current to a semiconductor light source; an abnormality detecting unit which detects abnormality of a positive-electrode-side output based on at least one of a power supply voltage or a supply voltage supplied to the semiconductor light source, and outputs signal indicating the abnormality; and a bypass unit which bypasses the supply current supplied from the current control unit in accordance with the signal indicating the abnormality.

Abstract: A vehicle lighting control device includes a switching unit to perform ON/OFF control of a driving current supplied to a semiconductor light source depending on a light control signal; and a constant-current control unit to perform constant-current control on the driving current. The constant-current control unit includes a switch unit to perform ON/OFF control of the switching unit; and a signal-maintaining unit to provide a voltage signal corresponding to the driving current to the switch unit when the switching unit performs ON control, and to provide continuously the voltage signal to the switch unit when the switching unit performs OFF control.

Abstract: A lighting circuit includes: a countercurrent prevention unit including a first control terminal and a second control terminal, the countercurrent prevention unit transmitting a first current or a second current; and a current controller including: a common terminal connected to the first control terminal and the second control terminal; and a switching terminal connected to the first control terminal, the current controller providing a first driving current or a second driving current from the common terminal to the light source. The countercurrent prevention unit further includes: a first rectifier, wherein voltage at the first control terminal is provided to the switching terminal through the first rectifier; a first P-FET provided between the first control terminal and the common terminal; a second P-FET provided between the second control terminal and the common terminal; and a second rectifier provided between the second P-PET and the common terminal.

Abstract: A semiconductor light source lighting circuit includes a transistor and a current detection resistor provided in series in a semiconductor light source current supply path, a control circuit for controlling the transistor so as to decrease any difference between the voltage occurring at the current detection resistor and a reference voltage, and a bypass resistor to establish a bypass path for the current supplied to the semiconductor light source, where a first end of the bypass path is located at a connection node between the transistor and the semiconductor light source.

Abstract: A vehicle lamp lighting control device includes: a current control unit which is of a non-insulation type and supplies a supply current to a semiconductor light source; an abnormality detecting unit which detects abnormality of a positive-electrode-side output based on at least one of a power supply voltage or a supply voltage supplied to the semiconductor light source, and outputs signal indicating the abnormality; and a bypass unit which bypasses the supply current supplied from the current control unit in accordance with the signal indicating the abnormality.

Abstract: A lighting control device includes a current driving portion for DC-controlling or PWM-controlling an LED unit, and a disconnection detection portion for detecting disconnection of the LED unit. The disconnection detection portion has a latch circuit and a reset portion. The latch circuit provides a disconnection detection signal after it is detected that disconnection has occurred for a prescribed time. The reset portion resets the disconnection detection signal based on prescribed conditions.

Abstract: A vehicle lighting control device includes a switching unit to perform ON/OFF control of a driving current supplied to a semiconductor light source depending on a light control signal; and a constant-current control unit to perform constant-current control on the driving current. The constant-current control unit includes a switch unit to perform ON/OFF control of the switching unit; and a signal-maintaining unit to provide a voltage signal corresponding to the driving current to the switch unit when the switching unit performs ON control, and to provide continuously the voltage signal to the switch unit when the switching unit performs OFF control.