Light emitting device and measurement apparatus

Patent metadata

Field	Value
Publication number	US-2023304789-A1
Application number	US-202217976879-A
Country	US
Kind code	A1
Filing date	Oct 31, 2022
Priority date	Mar 22, 2022
Publication date	Sep 28, 2023
Grant date	—

Abstract

A light emitting device includes: a light emitting section that includes a light emitting element; a capacitor section connected to the light emitting section; and a control section that controls a potential of the capacitor section when the light emitting element of the light emitting section emits light.

First claim

What is claimed is:

1 . A light emitting device comprising:
a light emitting section that includes a light emitting element; a capacitor section connected to the light emitting section; and a control section that controls a potential of the capacitor section when the light emitting element of the light emitting section emits light.

2 . The light emitting device according to claim 1 ,
wherein the control section sets the potential of the capacitor section to a first potential when a light emission current flowing through the light emitting section is on, and the control section sets the potential of the capacitor section from the first potential to a second potential that is higher in absolute value than the first potential when the light emission current flowing through the light emitting section is turned from on to off.

3 . The light emitting device according to claim 2 , further comprising:
a drive section connected to the light emitting section and the capacitor section to turn on or off the light emission current flowing through the light emitting section, wherein the control section sets the potential of the capacitor section from the first potential to the second potential in accordance with a timing when the drive section turns the light emission current from on to off.

4 . The light emitting device according to claim 2 ,
wherein the light emitting section has a first capacitor in parallel with the light emitting element, the capacitor section has a second capacitor, and the first potential or the second potential is a potential at which a displacement current flows through the first capacitor and the second capacitor in a series connection state.

5 . The light emitting device according to claim 4 ,
wherein the second capacitor has a capacitance that is once as much as that of the first capacitor or more.

6 . The light emitting device according to claim 5 ,
wherein the second capacitor has a capacitance that is four times as much as that of the first capacitor or less.

7 . The light emitting device according to claim 1 ,
wherein the light emitting section and the capacitor section are provided on a single semiconductor substrate, the capacitor section is constituted of a pn junction that is a structure that is equivalent to the light emitting element provided on the semiconductor substrate, and the light emitting section and the capacitor section are connected to each other through the semiconductor substrate.

8 . The light emitting device according to claim 7 ,
wherein the control section applies, to the capacitor section, a potential that does not apply a forward bias to the pn junction.

9 . The light emitting device according to claim 1 ,
wherein the light emitting section includes a plurality of light emitting elements, the capacitor section is constituted of a structure that is equivalent to the light emitting elements, the light emitting device includes a select section that selects a light emitting element to be caused to emit light, and the select section is stacked on the capacitor section.

10 . The light emitting device according to claim 9 ,
wherein, during light emission in which the selected light emitting element is caused to emit light, the control section sets the capacitor section to a potential that is different from that during selection in which the select section selects the light emitting element to be caused to emit light.

11 . The light emitting device according to claim 10 ,
wherein the control section sets the potential of the capacitor section to a first potential when the select section makes the selection, and sets the potential of the capacitor section to a second potential that is higher in absolute value than the first potential when the select section has ended the selection.

12 . The light emitting device according to claim 1 ,
wherein the control section sets the potential of the capacitor section to a floating state during light emission.

13 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 1 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

14 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 2 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

15 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 3 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

16 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 4 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

17 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 5 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

18 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the measurement apparatus comprising:
the light emitting device according to claim 6 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

19 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 7 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

20 . A measurement apparatus that measures a three-dimensional shape of an object to be measured, the apparatus comprising:
the light emitting device according to claim 8 ; and a light receiving section that receives light output from the light emitting section of the light emitting device and reflected by the object to be measured.

Assignees

• Fujifilm Business Innovation Corp
• Fujifilm Corp

Inventors

• Takeyama Kei
• Iguchi Daisuke
• Ono Seiji
• Sakita Tomoaki
• Kondo Takashi
• Hayakawa Junichiro

Classifications

• H01S5/423

  having a vertical cavity · CPC title

• H01S5/0428

  for applying pulses to the laser · CPC title

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title

• G01S7/484

  Transmitters · CPC title

• G01S17/894

  Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar · CPC title