Object detector, sensing device, and mobile apparatus

Patent metadata

Field	Value
Publication number	US-10795019-B2
Application number	US-201715632553-A
Country	US
Kind code	B2
Filing date	Jun 26, 2017
Priority date	Jul 1, 2016
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

An object detector includes a light-emitting system and a light-receiving system. The light-emitting system includes a light source including a plurality of light-emitting elements disposed in one-axis direction. The light-emitting system emits light. The light-receiving system receives the light emitted from the light-emitting system and reflected by an object. The plurality of light-emitting elements emits a plurality of light beams to a plurality of areas differing in the one-axis direction. The amount of light to illuminate some of the plurality of areas is different from the amount of light to illuminate other area other than the some of the plurality of areas.

First claim

What is claimed is:

1. An object detector comprising:
a light-emitting system including a light source that includes a plurality of light-emitting elements, each of the plurality of light-emitting elements comprising a laser, the light-emitting system to emit light; and
a light-receiving system, comprising a plurality of photodetectors, to receive the light emitted from the light-emitting system and reflected by an object;
wherein, in an XYZ three-dimensional coordinate system, the plurality of light-emitting elements is disposed in a light-emitting element array along a Z axis in a Z-axis direction in a YZ plane,
wherein the plurality of light-emitting elements emit a plurality of light beams to a plurality of areas at different positions along the Z axis in the Z-axis direction from the plurality of light-emitting elements, and
wherein an amount of light to illuminate some of the plurality of areas is different from an amount of light to illuminate other area other than the some of the plurality of areas.

2. The object detector according to claim 1 , wherein the Z-axis direction is a vertical direction.

3. The object detector according to claim 1 ,
wherein the light-emitting system further includes an optical system to guide the plurality of light beams emitted from the plurality of light-emitting elements to the plurality of areas, and
wherein the optical system is configured such that some of light rays emitted from at least one of the plurality of light-emitting elements are lost while passing through the optical system.

4. The object detector according to claim 3 ,
wherein the optical system includes a coupling lens disposed in an optical path of the plurality of light beams emitted from the plurality of light-emitting elements, and
wherein only other light rays other than the some of the light rays emitted from the at least one of the plurality of light-emitting element pass through the coupling lens.

5. The object detector according to claim 4 , wherein a center of the light source is displaced relative to a center of the coupling lens along the Z-axis direction.

6. The object detector according to claim 3 ,
wherein the optical system includes a reflector, and
wherein the reflector has a rotation axis parallel to the Z-axis direction such that the some of the light rays emitted from the at least one of the plurality of light-emitting elements do not strike the reflector.

7. The object detector according to claim 6 , wherein the reflector is a light deflector having a rotation axis parallel to the Z-axis direction.

8. The object detector according to claim 1 ,
wherein the light source includes a plurality of the light-emitting element arrays disposed along a direction perpendicular to the Z-axis direction, and
wherein each of the plurality of light-emitting element arrays includes the plurality of light-emitting elements.

9. The object detector according to claim 1 , wherein a light-emitting amount differs between some of the plurality of light-emitting elements corresponding to the some of the plurality of areas and other light-emitting element corresponding to the other area other than the some of the plurality of areas.

10. The object detector according to claim 9 ,
wherein the light-emitting system further includes a plurality of drive circuits to respectively drive the plurality of light-emitting elements,
wherein each of the plurality of drive circuits includes a capacitor to accumulate an electric charge to be supplied to a corresponding light-emitting element of the plurality of light-emitting element, and
wherein the capacitor differs in capacitance between some of the plurality of drive circuits, which drive a corresponding some of the plurality of light-emitting elements, and other drive circuits other than the some of the plurality of drive circuits to drive a corresponding other light-emitting elements other than the corresponding some of the plurality of light-emitting elements.

11. The object detector according to claim 9 ,
wherein each of the plurality of light-emitting elements includes a plurality of light-emitting sections, and
wherein a number of the plurality of light-emitting sections for each of the plurality of light-emitting elements differs between the some of the plurality of light-emitting elements and the other light-emitting element other than the some of the plurality of light-emitting elements.

12. A sensing device comprising:
the object detector according to claim 1 ; and
a monitoring controller to obtain object data including at least one of a presence or an absence of the object, a direction of movement of the object, and a speed of movement of the object based on an output of the object detector.

13. The sensing device according to claim 12 , wherein the monitoring controller further determines a presence or an absence of danger based on at least one of positional information and movement information of the object.

14. A mobile apparatus comprising:
the sensing device according to claim 12 ; and
a mobile object provided with the sensing device.

15. A mobile apparatus comprising:
the object detector according to claim 1 ; and
a mobile object provided with the object detector.

16. A method comprising:
emitting light from a light-emitting system including a light source that includes a plurality of light-emitting elements, each of the plurality of light-emitting elements comprising a laser; and
receiving, by a light-receiving system comprising a plurality of photodetectors, the light emitted from the light-emitting system and reflected by an object;
wherein, in an XYZ three-dimensional coordinate system, the plurality of light-emitting elements is disposed in a light-emitting element array along a Z axis in a Z-axis direction in a YZ plane,
wherein the plurality of light-emitting elements emit a plurality of light beams to a plurality of areas at different positions along the Z axis in the Z-axis direction from the plurality of light-emitting elements, and
wherein an amount of light to illuminate some of the plurality of areas is different from an amount of light to illuminate other area other than the some of the plurality of areas.

Assignees

• Ricoh Co Ltd

Inventors

• Imai Shigeaki

Classifications

• G01S17/42 Primary

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01V8/20

  using multiple transmitters or receivers · CPC title

• G01S7/484

  Transmitters · CPC title

• G01S7/4815

  using multiple transmitters · CPC title

• G01S17/04 Primary

  Systems determining the presence of a target · CPC title