To provide a lighting circuit capable of obtaining a desired light distribution pattern even in a low voltage state or suppressing uneven brightness.SOLUTION: A drive circuit 610 receives an input voltage Vand supplies a drive current Ito a semiconductor light source 502. Each of bypass switches SW# (#=1, 2, ... m) is connected in parallel to a corresponding portion 504_# of a plurality of light emitting elements 504. A bypass control unit 650 generates phase-shifted m-phase gate pulse signals Sg1 to Sgm to control m bypass switches SW1 to SWm according to the m-phase gate pulse signals. The bypass control unit 650 changes a duty ratio of each gate pulse signal Sg# in accordance with target brightness of a corresponding portion and corrects the duty ratio in accordance with the input voltage V.SELECTED DRAWING: Figure 2

    【課題】低電圧状態においても、所望の配光パターンを得ることができ、あるいは輝度ムラを抑制可能な点灯回路を提供する。【解決手段】駆動回路610は、入力電圧VINを受け、半導体光源502に駆動電流IOUTを供給する。バイパススイッチSW#(#=1,2,…m)は、それぞれが複数の発光素子504の対応する部分504_#と並列に接続される。バイパス制御部650は、位相シフトしているm相のゲートパルス信号Sg1〜Sgmを生成し、m相のゲートパルス信号に応じてm個のバイパススイッチSW1〜SWmを制御する。バイパス制御部650は、各ゲートパルス信号Sg#のデューティ比を、対応する部分の目標輝度に応じて変化させるとともに、入力電圧VINに応じて補正する。【選択図】図2


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    Title :

    LIGHTING CIRCUIT AND VEHICLE LIGHTING


    Additional title:

    点灯回路および車両用灯具


    Contributors:

    Publication date :

    2020-06-18


    Type of media :

    Patent


    Type of material :

    Electronic Resource


    Language :

    Japanese


    Classification :

    IPC:    H05B ELECTRIC HEATING , Elektrische Heizung / B60Q ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL , Anordnung von Signal- oder Beleuchtungsvorrichtungen, deren Einbau oder Halterung oder deren Schaltkreise bei Fahrzeugen allgemein / H01L Halbleiterbauelemente , SEMICONDUCTOR DEVICES



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