DRIVE CIRCUIT AND LIGHT SOURCE DEVICE

• Main Author: KONDO HIDEKI
• Format: Patent
• Language: English; Japanese
• Published: 05.04.2023
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES USING STIMULATED EMISSION; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY

To provide a drive circuit and a light source device that can suppress undershooting even when a light-emitting element is placed in pulse oscillation.SOLUTION: A drive circuit comprises: a switching circuit which switches between a first state in which a light-emitting element is supplied with a current equal to or larger than a threshold current large enough to emit light of predetermined output or larger from the light-emitting element so as to let the light-emitting element emit the light and a second state in which the current supplied to the light-emitting element is decreased in level to less than the threshold current so that the light-emitting element is placed in pulse oscillation; and a DC current adjusting circuit which supplies the light-emitting element with a bias current of level corresponding to undershooting occurring during trailing of the pulse oscillation within a range less than the threshold current of the light-emitting element in the second state.SELECTED DRAWING: Figure 1 【課題】発光素子をパルス発振させる際にも、アンダーシュートを抑制できる駆動回路及び光源装置を提供する。【解決手段】駆動回路は、発光素子から所定の出力以上の光を出射可能な閾値電流以上の大きさの電流を、前記発光素子に供給することにより、前記発光素子から光を出射する第１状態と、前記発光素子に供給する電流の大きさを前記閾値電流未満にする第２状態と、を切り替え、前記発光素子をパルス発振させるスイッチング回路と、前記第２状態の時に、前記発光素子の前記閾値電流未満の範囲内において、前記パルス発振の立下り時に発生するアンダーシュートの大きさに応じた大きさのバイアス電流を前記発光素子に供給可能とする直流電流調整回路と、を備える。【選択図】図１