Koito Manufacturing Company, Ltd.

Takao Sugiyama

Takayoshi Kitagawa

Kotaro Matsui

Susumu Ogo

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.

Lighting circuit and vehicle lamp

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.

Lighting circuit

A vehicle lamp includes a lamp body having an opening, a front cover attached to the lamp body to close the opening, and a first optical unit disposed inside a lamp chamber defined by the lamp body and the cover. The first optical unit includes a printed wiring board having a first section formed with a first conductor pattern and a second section formed with a second conductor pattern electrically coupled to the first conductor pattern, an LED mounted on the first section of the printed wiring board, and a lighting control circuit provided on the second section of the printed wiring board to control a lighting of the LED. The first optical unit further has a bracket supporting the printed wiring board in a horizontal manner, and a drip-preventive cover covering the lighting control circuit. The drip-preventive cover is provided on the bracket.

Vehicle lamp having an LED and a drip-preventive cover

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.

Light source lighting circuit and lamp system for vehicle

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.

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Shizuoka, Japan

Takao Sugiyama