LIGHT SOURCE DRIVING APPARATUS AND LIGHT SOURCE DRIVING METHOD

To provide a light source driving apparatus and a light source driving method capable of suppressing reduction in luminance of a light source when input voltage is temporarily reduced.SOLUTION: The light source driving apparatus includes a dimming unit, a voltage generation unit and a suppression unit. The dimming unit performs dimming of a light source by PWM control. The voltage generation unit generates voltage to be supplied to the light source by repeatedly turning on/off a switching element for supplying voltage to the light source during the ON period of the light source synchronized with the PWM control and turning off the switching element during the OFF period of the light source synchronized with the PWM control. The suppression unit suppresses reduction of output voltage by repeatedly turning on/off the switching element without synchronizing with the PWM control at least in either one period out of a period in which a voltage value of at least one of input voltage and output voltage is less than a predetermined voltage value and a period in which a reduction rate of the voltage value exceeds a predetermined reduction rate.SELECTED DRAWING: Figure 1 【課題】入力電圧が一時的に低下した場合に、光源の輝度が低下することを抑制することができる光源駆動装置および光源駆動方法を提供すること。【解決手段】実施形態に係る光源駆動装置は、調光部と、電圧生成部と、抑制部とを備える。調光部は、ＰＷＭ制御によって光源の調光を行う。電圧生成部は、ＰＷＭ制御に同期した光源のオン期間に、光源へ電圧を供給するスイッチング素子を繰り返しオンオフさせ、ＰＷＭ制御に同期した光源のオフ期間に、スイッチング素子をオフさせて光源に供給する電圧を生成する。抑制部は、入力電圧および出力電圧の少なくともいずれかの電圧値が所定電圧値を下回る期間、および電圧値の低下率が所定低下率を超える期間の少なくともいずれかの期間に、ＰＷＭ制御とは同期させずにスイッチング素子を繰り返しオンオフさせて出力電圧の低下を抑制する。【選択図】図１