Light source device, light-emitting unit, and measurement apparatus

1 . A light-emitting unit comprising:

a plurality of light-emitting sections;

a setter that is electrically connected to the plurality of light-emitting sections and that sets, among the plurality of light-emitting sections, a light-emitting section to a state in which the light-emitting section is able to emit light; and

a first terminal that supplies a first voltage to the light-emitting section,

wherein

each of the plurality of light-emitting sections includes a light-emitting diode and a drive thyristor, the drive thyristor being connected in series with the light-emitting diode and driving the light-emitting diode,

the setter includes a plurality of setting elements and shifts a setting element which is to be turned ON between the plurality of setting elements so as to set a corresponding drive thyristor to be an ON state, the corresponding drive thyristor being a drive thyristor included in a light-emitting section which is to emit light among the plurality of light-emitting sections, and

the setter includes:

a first part that receives the first voltage,

a second part that receives a reference potential, the reference potential being different from the first voltage, and

an insulator interposed between the first part and the second part.

2 . The light-emitting unit according to claim 1 , wherein:

the light-emitting diode includes a lower side layer, an active layer and an upper side layer,

the drive thyristor is stacked on the light-emitting diode,

the plurality of setting elements is stacked on which the lower side layer, the active layer and the upper side layer entirely remain without being removed, and

the insulator is disposed on the upper side layer between the first part and the second part.

3 . The light-emitting unit according to claim 2 , wherein

the insulator is a groove disposed between the first part and the second part.

4 . The light-emitting unit according to claim 1 , wherein:

the light-emitting unit is constituted by laminating a plurality of semiconductor layers, and

the first part and the second part are disposed at different positions in a direction perpendicular to stacking direction.

5 . The light-emitting unit according to claim 1 , further comprising:

a second terminal supplying, to the setter, a second voltage being lower than the first voltage and higher than the reference potential.

6 . A measurement apparatus comprising:

the light source device according to claim 1 ; and

a light receiver that receives light which is emitted from a corresponding light-emitting section of the plurality of light-emitting sections of the light source device and which is reflected by a subject to be measured.

7 . A light source device comprising:

a plurality of light-emitting means;

setting means, electrically connected to the plurality of light-emitting means, for setting, among the plurality of light-emitting means, a light-emitting means to a state in which the light-emitting means is able to emit light; and

means for supplying a first voltage to the light-emitting means,

wherein

each of the plurality of light-emitting means includes a light-emitting diode and a drive thyristor, the drive thyristor being connected in series with the light-emitting diode and driving the light-emitting diode,

the setting means includes a plurality of setting elements and shifts a setting element which is to be turned ON between the plurality of setting elements so as to set a corresponding drive thyristor to be an ON state, the corresponding drive thyristor being a drive thyristor included in a light-emitting means which is to emit light among the plurality of light-emitting means, and

the setting means includes:

a first part that receives the first voltage,

a second part that receives a reference potential, the reference potential being different from the first voltage, and

an insulating means interposed between the first part and the second part.