DISTANCE MEASURING DEVICE AND DISTANCE MEASURING METHOD

• US 20180128918A1
• Filed: 09/04/2017
• Published: 05/10/2018
• Est. Priority Date: 11/08/2016
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: OTA, Yutaka, HIRONO, Masatoshi, UCHIYAMA, Mineharu, MATSUMOTO, Nobu, KUBOTA, Hiroshi, OHTSUKA, Shinichi
• Granted Patent: US 10,816,663 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4814 of transmitters alone
• CPC Class Codes: G01S 7/4816 of receivers alone

Abstract

A distance measuring device includes a laser light source, an irradiation optical system comprising a beam spreader which is configured to spread the laser light about a first optical axis, a light reception optical system having a second optical axis different from the first optical axis and positioned to receive reflected light of the laser light from the object for measuring a distance to the object, a sensor with light receiving elements arranged in a first direction, the sensor being positioned to receive light reflected from the object which has passed through the light reception optical system, and a distance measuring unit configured to acquire distance information relating to the object based on the difference in time between emission of the laser light source and the reception of the reflected light at each of the plurality of light receiving elements.

Claims

1. A distance measuring device, comprising:

a laser light source configured to emit laser light;

an irradiation optical system comprising a beam spreader which is configured to spread the laser light emitted from the laser light about a first optical axis in a first direction, the first optical axis intersecting an object the distance to which is to be measured;

a light reception optical system having a second optical axis that is different than the first optical axis, the light reception optical system positioned to receive reflected light of the laser light directed toward the object, the distance to which is to be measured;

a sensor comprising a plurality of light receiving elements arranged in the first direction, the sensor positioned to receive light reflected from the object, the distance to which is to be measured which has passed through the light reception optical system; and

a distance measuring unit configured to acquire distance information relating to the object the distance to which is to be measured based on the difference in time between emission of the laser light source and the reception of the reflected light at each of the plurality of light receiving elements.

2. The distance measuring device according to claim 1, further comprising:

a rotation unit that rotates the laser light source, the irradiation optical system, the sensor, and the light reception optical system about a rotation axis which is parallel to the first direction.

3. The distance measuring device according to claim 2, wherein at least a part of an irradiation surface of the irradiation optical system is arranged within a light reception range of the light reception optical system.

4. The distance measuring device according to claim 2, wherein the sensor is configured with two one-dimensional sensors that are arranged parallel to the first direction and have different levels of sensitivity.

5. The distance measuring device according to claim 2, wherein the optical axis of the irradiation optical system and the optical axis of the light reception optical system are parallel to each other, and each of the optical axes intersects with the rotation axis.

6. The distance measuring device according to claim 2, wherein the optical axis of the irradiation optical system and the optical axis of the light reception optical system are parallel to each other and are spaced from one another in a direction that is perpendicular to the rotation axis.

7. The distance measuring device of claim 2, further comprising a mirror comprising a reflecting surface, the reflecting surface inclined at an angle to the rotation axis.

8. A distance measuring method for measuring the distance to an object, comprising:

providing a light source emitting a beam of light;

spreading the emitted light in a first direction;

receiving reflected light from a measured object at a sensor that has a plurality of light receiving elements; and

acquiring distance information from the laser light source to a plurality of points on the measured object based on a difference between a point in time of the emission of the light from the laser light source and a point in time of the reception of the reflected light at each of the plurality of light receiving elements.

9. The method according to claim 8, wherein

the spreading light includes a first optical axis and a first spreading angle;

and

the reflected light has a second optical axis.

10. The method according to claim 9, wherein the first and second optical axis are parallel to one another.

11. The method according to claim 9, further comprising rotating the spreading light and the light detector about a common axis of rotation, wherein the first and second optical axes intersect the axis of rotation.

12. The method according to claim 9, further comprising rotating the spreading beam of light and the light detector about a common axis of rotation, wherein the first and second optical axes are offset from the axis of rotation and parallel to each other.

13. The method according to claim 9, wherein at least a portion of the light source is within the path of light reflected from the object.

14. The method according to claim 9, wherein at least two of the sensors have different sensitivities to light.

15. The method according to claim 8, wherein the light source is a laser light source.

16. A distance measuring device for measuring the distance to an object, comprising:

a light beam emitter configured to emit a beam of light;

a beam spreader configured transmit the beam of light along a first optical axis and spread the beam with respect to the first optical axis, wherein the spread width of the beam increases as the distance of the beam from the beam spreader increases; and

a light detector having a second optical axis, the first and second optical axes parallel to, and spaced from, one another.

17. The distance measuring device according to claim 16, wherein light beam emitter, the beam spreader, and the light detector are contained in a housing, and the housing is rotatable about a rotation axis.

18. The distance measuring device according to claim 17, wherein the first and second optical axes are parallel to each other and orthogonal to the axis of rotation.

19. The distance measuring device according to claim 18, wherein the first and second optical axes intersect the axis of rotation.

20. The distance measuring device according to claim 16, wherein the light detector comprises a plurality of detection elements.