Abstract: An abnormality of output laser light is detected for enhancement in safety. A light-source drive device includes a light-source control unit, a light-receiving unit, and an abnormality detection unit. The light-source control unit included in the light-source drive device controls light emission of a light source. The light-receiving unit included in the light-source drive device receives light from the light source through an output part allowing outward output of light of the light source. The abnormality detection unit included in the light-source drive device detects an abnormality of the light output from the output part, on the basis of the received light.

Abstract: The present invention relates to a driving device, a driving method, and a light-emitting unit that make it possible to appropriately drive a light-emitting element. The driving device according to the present invention includes: a setting section (161) that sets at least one of a bias current of a light-emitting element (an LD 121) or a target current for setting output light from the light-emitting element (the LD 121) to desired intensity on the basis of a result of detection of an offset light amount when the light-emitting element (the LD 121) does not emit light; and an output controller (164) that controls an output of a driving current of the light-emitting element (the LD 121) on the basis of at least one of the set bias current or the set target current. The detection of the offset light amount is performed by a light-receiving element (a PD 122) that receives a portion of the output light. The present invention is applicable to a ranging module, for example.

Abstract: The configuration of a light source driving device, which drives a plurality of light sources that emit light to an object to measure the distance to the object, is simplified. A light source device drives a plurality of light sources provided in a system that measures the distance to the object. The light source driving device is provided in the light source device. The light source driving device includes a light source control unit that individually controls emission of light from a plurality of light sources that emit the light to an object to measure a distance to the object.

Abstract: An object of the present invention is to reduce errors caused by changes in delay time when driving a light-emitting element. A light-emission driving device (10) includes: a light-emission current detection unit (401) (12); a phase difference detection unit (300); and a delay unit (200). The light-emission current detection unit (401) (12) detects a light-emission current for causing a light-emitting element (20) to emit light, the light-emission current being supplied from a light-emission driving unit (110). The phase difference detection unit (300) detects a phase difference between the detected light-emission current and a drive signal for controlling the supply of the light-emission current in the light-emission driving unit (110). The delay unit (200) adjusts propagation delay of the drive signal in accordance with the detected phase difference, and supplies the adjusted drive signal to the light-emission driving unit (110) as a drive signal.

Abstract: A configuration of a light emission device that shortens a light emission latency time of a light emitting element is simplified. A light emission drive circuit includes a light emission current wire, a light emission current switch, a preliminary current wire, and a preliminary current switch. The light emission current wire flows a light emission current for causing a light emitting element to emit light, is the light emitting element. The light emission current switch is connected to the light emission current wire, and controls the light emission current. The preliminary current wire flows, in the light emission current wire, a preliminary current for exciting an inductance component of the light emission current wire before a light emission period being a period in which the light emission current flows in the light emitting element. The preliminary current switch is connected to the preliminary current wire, and controls the preliminary current.

Abstract: An abnormality of output laser light is detected for enhancement in safety. A light-source drive device includes a light-source control unit, a light-receiving unit, and an abnormality detection unit. The light-source control unit included in the light-source drive device controls light emission of a light source. The light-receiving unit included in the light-source drive device receives light from the light source through an output part allowing outward output of light of the light source. The abnormality detection unit included in the light-source drive device detects an abnormality of the light output from the output part, on the basis of the received light.

Abstract: The present invention relates to a driving device, a driving method, and a light-emitting unit that make it possible to appropriately drive a light-emitting element. The driving device according to the present invention includes: a setting section (161) that sets at least one of a bias current of a light-emitting element (an LD 121) or a target current for setting output light from the light-emitting element (the LD 121) to desired intensity on the basis of a result of detection of an offset light amount when the light-emitting element (the LD 121) does not emit light; and an output controller (164) that controls an output of a driving current of the light-emitting element (the LD 121) on the basis of at least one of the set bias current or the set target current. The detection of the offset light amount is performed by a light-receiving element (a PD 122) that receives a portion of the output light. The present invention is applicable to a ranging module, for example.

Abstract: A correction circuit includes a correction section configured to superpose a second current pulse on a first current pulse, and thereby correcting a waveform of the first current pulse, the first current pulse being output from a current source configured to drive a surface-emitting semiconductor laser in a pulsed manner, the correction section being configured to allow the second pulse to have a waveform obtained through attenuating a crest value of the second current pulse with time, increasing an initial crest value of the second current pulse by an amount that is larger as magnitude of the first current pulse is larger, and allowing the amount by which the initial crest value is increased to be smaller as ambient temperature of the semiconductor laser is higher, and being configured to output the second pulse having the waveform.

Abstract: A driving device includes: a driving circuit configured to provide a drive current; a first detecting circuit; a second detecting circuit configured to detect a first reference current or a physical quantity corresponding thereto, as well as a second reference current or a physical quantity corresponding thereto; a first generating circuit configured to generate an additive voltage as a control voltage at a light-emission time of a light-emitting element, and further to generate a second voltage as a control voltage at a non-light-emission time of the light-emitting element; and a second generating circuit configured to generate a third reference current. The second detecting circuit has a first adder circuit that generates the first reference current by adding the second reference current and the third reference current with each other.

Abstract: A drive circuit and a drive current correcting method are described herein. The drive circuit comprises a current source that outputs a drive current, and a correction circuit that outputs a correction current. The correction circuit includes a first RC time constant circuit. An output terminal of the current source is connected to an output terminal of the correction circuit.

Abstract: A correction circuit includes a correction section configured to superpose a second current pulse on a first current pulse, and thereby correcting a waveform of the first current pulse, the first current pulse being output from a current source configured to drive a surface-emitting semiconductor laser in a pulsed manner, the correction section being configured to allow the second pulse to have a waveform obtained through attenuating a crest value of the second current pulse with time, increasing an initial crest value of the second current pulse by an amount that is larger as magnitude of the first current pulse is larger, and allowing the amount by which the initial crest value is increased to be smaller as ambient temperature of the semiconductor laser is higher, and being configured to output the second pulse having the waveform.

Abstract: A driving device includes: a driving circuit configured to provide a drive current; a first detecting circuit; a second detecting circuit configured to detect a first reference current or a physical quantity corresponding thereto, as well as a second reference current or a physical quantity corresponding thereto; a first generating circuit configured to generate an additive voltage as a control voltage at a light-emission time of a light-emitting element, and further to generate a second voltage as a control voltage at a non-light-emission time of the light-emitting element; and a second generating circuit configured to generate a third reference current. The second detecting circuit has a first adder circuit that generates the first reference current by adding the second reference current and the third reference current with each other.

Abstract: A correction circuit is provided, which may reduce dullness of a light output waveform due to wavelength detuning. The correction circuit includes an RC time constant circuit. The RC time constant circuit is used to correct a waveform of a current pulse outputted from a current source, the current source driving a surface-emitting semiconductor laser in a pulsed manner, so that a pulse waveform of light output of the semiconductor laser is approximately a rectangle.

Abstract: A correction circuit includes: a temperature rise derivation section which derives a temperature rise amount of a first channel of a multi-channel surface-emitting laser array due to the heating by at least one or a plurality of second channels adjacent to the first channel out of all channels included in the laser array; and a first correction section which corrects a waveform of an electric current pulse which is output from an electric current source capable of independently driving the laser array for each channel, to the first channel, based on the temperature rise amount derived by the temperature rise derivation section.

Abstract: A drive circuit and a drive current correcting method are described herein. The drive circuit comprises a current source that outputs a drive current, and a correction circuit that outputs a correction current. The correction circuit includes a first RC time constant circuit. An output terminal of the current source is connected to an output terminal of the correction circuit.

Abstract: Disclosed herein is a laser driver including a light emission controlling section configured to stop generation of a control voltage by a control voltage generating section, causing a given voltage corresponding to a magnitude of a reference current to be outputted to an input node of a first emitter follower to operate the first emitter follower for a first time period from start of a light emission time period, release stop of the generation of the control voltage by the control voltage generating section, causing the control voltage to be outputted to the input node of the first emitter follower to operate the first emitter follower until end of the light emission time period of the laser, and operate a second emitter follower to discharge electric charges accumulated in the laser for a second time period after the end of the light emission time period of the laser.

Abstract: A correction circuit is provided, which may reduce dullness of a light output waveform due to wavelength detuning. The correction circuit includes an RC time constant circuit. The RC time constant circuit is used to correct a waveform of a current pulse outputted from a current source, the current source driving a surface-emitting semiconductor laser in a pulsed manner, so that a pulse waveform of light output of the semiconductor laser is approximately a rectangle.

Abstract: A gain control circuit to determine gain by a current ratio of mutual conductance.

Abstract: Disclosed herein is a laser driver including a light emission controlling section configured to stop generation of a control voltage by a control voltage generating section, causing a given voltage corresponding to a magnitude of a reference current to be outputted to an input node of a first emitter follower to operate the first emitter follower for a first time period from start of a light emission time period, release stop of the generation of the control voltage by the control voltage generating section, causing the control voltage to be outputted to the input node of the first emitter follower to operate the first emitter follower until end of the light emission time period of the laser, and operate a second emitter follower to discharge electric charges accumulated in the laser for a second time period after the end of the light emission time period of the laser.

Abstract: A gain control circuit to determine gain by a current ratio of mutual conductance.