OPTICAL MEASUREMENT DEVICE AND VEHICLE

• US 20140036071A1
• Filed: 08/01/2013
• Published: 02/06/2014
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Tadashi Nakamura
• Inventors: NAKAMURA, Tadashi, Imai, Shigeaki
• Granted Patent: US 9,568,358 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01J 1/0422 using light concentrators, collectors or condensers
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

Disclosed is an optical measurement device including a first light source, an optical element that condenses a light beam emitted from the first light source, a light irradiator that irradiates the light beam onto an object; and a photo detector that detects reflected light or scattered light of the light beam from the object through an imaging system, the light beam being irradiated onto the object, wherein a first optical path length from the first light source to a first conjugate image of the first light source by the optical element is different from a second optical path length from the photo detector to a second conjugate image of the photo detector by the imaging system at least in a first direction.

Claims

1. An optical measurement device comprising:

a first light source;

an optical element configured to condense a light beam emitted from the first light source;

a light irradiator configured to irradiate the light beam onto an object; and

a photo detector configured to detect reflected light or scattered light of the light beam from the object through an imaging system, the light beam being irradiated onto the object,

wherein a first optical path length from the first light source to a first conjugate image of the first light source by the optical element is different from a second optical path length from the photo detector to a second conjugate image of the photo detector by the imaging system at least in a first direction.

2. The optical measurement device according to claim 1, further comprising:

a deflector configured to deflect and scan the light beam which passes through the optical element, wherein the deflector is disposed downstream of the irradiator,

wherein, when a direction in which the deflector deflects and scans is a main scanning direction, and a direction which is perpendicular to the main scanning direction is a sub-scanning direction, the first direction is one of the main scanning direction and the sub-scanning direction.

3. The optical measurement device according to claim 1,

wherein the optical element has a first principal point and a first focal length at least in the first direction, wherein the first principal point is disposed at a first position which is separated from the first light source by the first focal length, and

wherein the imaging system includes a first imaging element which has a second principal point and a second focal length at least in the first direction, wherein the second principal point is disposed at a second position which is separated from the photo detector by the second focal length.

4. The optical measurement device according to claim 3,

wherein the first light source includes a plurality of second light sources, and second light beams from the corresponding second light sources irradiate different regions of the object,

wherein the imaging system includes a second imaging element which has a third principal point and a third focal length in a second direction, the second direction being different from the first direction, and

wherein the second focal length is different from the third focal length.

5. The optical measurement device according to claim 4,

wherein the second principal point is disposed at a third position which is separated from the photo detector by a distance which is greater than the second focal length, and

wherein the third principal point is disposed at a fourth position which is separated from the photo detector by the third focal length.

6. The optical measurement device according to claim 1,

wherein, when a closest detection distance of the optical measurement device is a minimum detection distance, a fifth position of the second conjugate image of the photo detector is a point which is separated from the optical measurement device by the minimum detection distance.

7. A vehicle which includes an optical measurement device, wherein the optical measurement device comprises:

a first light source;

an optical element configured to condense a light beam emitted from the first light source;

a light irradiator configured to irradiate the light beam onto an object; and

a photo detector configured to detect reflected light or scattered light of the light beam from the object through an imaging system, the light beam being irradiated onto the object,

wherein a first optical path length from the first light source to a first conjugate image of the first light source by the optical element is different from a second optical path length from the photo detector to a second conjugate image of the photo detector by the imaging system at least in a first direction.

8. The vehicle according to claim 7,

wherein the irradiator of the optical measurement device irradiates light outside the vehicle,

wherein the photo detector detects reflected light or scattered light of the light, and

wherein the optical measurement device is configured to obtain information of the object from outside the vehicle, based on a signal which is detected by the photo detector.