ELECTRONIC APPARATUS AND METHOD FOR MEASURING DIRECTION OF OUTPUT LASER LIGHT

• US 20150369920A1
• Filed: 06/18/2015
• Published: 12/24/2015
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Original Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Inventors: Horibe, Ryusuke, Hirai, Tomohisa, Setono, Shingo, Murayama, Manabu, Masuda, Yuichiro, Mushimoto, Atsushi
• Granted Patent: US 9,829,579 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 26/127 Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors G02B27/0031 takes precedence

Abstract

An electronic apparatus includes a light source that outputs a laser light; a scanning unit that scans the laser light; a reflective member having a reflective surface that reflects the laser light; a light-receiving unit that receives a first reflected light reflected by the reflective member; and a signal processing unit that calculates a distance from the light source to the reflective surface using the first reflected light and determines a direction in which the laser light is output using the distance.

Claims

1. An electronic apparatus, comprising:

a light source that outputs a laser light;

a scanning unit that scans the laser light;

a reflective member comprising a reflective surface that reflects the laser light;

a light-receiving unit that receives a first reflected light reflected by the reflective member; and

a signal processing unit that calculates a distance from the light source to the reflective surface using the first reflected light and determines, based on the distance, a direction in which the laser light is output.

2. The electronic apparatus according to claim 1, wherein the reflective member is formed to cause a scanning time in which the reflective surface is scanned with the laser light in a predetermined scanning direction to be constant.

3. The distance measurement device according to claim 1, wherein the reflective surface is a rectangular plane.

4. The electronic apparatus according to claim 1, wherein the reflective surface is a rectangular curved surface.

5. The electronic apparatus according to claim 1, wherein white paint is painted on the reflective surface.

6. The electronic apparatus according to claim 1, wherein a distance from the scanning unit to one short side of the reflective surface of the reflective member is shorter than a distance from the scanning unit to the other short side of the reflective surface.

7. The electronic apparatus according to claim 1, wherein the reflective member is disposed within a scanning range of the laser light except an opening portion of a casing.

8. The electronic apparatus according to claim 1, wherein

the scanning unit

changes a direction in which the laser light is scanned to a first scanning direction and to a second scanning direction that intersects the first scanning direction, and

by changing an angle in the second scanning direction after being scanned in the first scanning direction while the angle in the second scanning direction is maintained, changes the direction in which the laser light is scanned two-dimensionally.

9. The electronic apparatus according to claim 8, wherein

the light-receiving unit further receives a second reflected light that is the laser light reflected by an object, and

the signal processing unit

calculates, while an angle in the second scanning direction of when the light-receiving unit receives the second reflected light is maintained, a distance from the light source to the reflective member using the first reflected light, and

calculates an angle of the laser light in the first scanning direction of when the second reflected light is received using the calculated distance and an angle in the first scanning direction of when the first reflected light is received.

10. The electronic apparatus according to claim 1, wherein the signal processing unit calculates the distance based on a phase difference between a phase of the laser light and a phase of the light received by the light-receiving unit.

11. The electronic apparatus according to claim 1, wherein the signal processing unit calculates an angle in the first scanning direction of when an object reflecting a second reflected light is detected, based on a timing at which the light-receiving unit receives the first reflected light and a time when the object is detected.

12. The electronic apparatus according to claim 11, wherein

the signal processing unit:

acquires a timing at which the object is detected,

detects an interval between the timing at which the light-receiving unit receives the first reflected light and a time when the laser light passes through the reflective member,

calculates a sine wave indicating displacements in a direction of the laser light relative to time using the interval and a direction in which the reflective member is disposed, and

calculates the direction of the laser light using the sine wave and the timing at which the object is detected.

13. The electronic apparatus according to claim 1, wherein

the signal processing unit comprises a reflective member detection unit, and

the reflective member detection unit determines, based on a threshold, whether a distance calculated by the signal processing unit is a distance from a laser diode to an object or a distance from the laser diode to the reflective member.

14. The electronic apparatus according to claim 1, wherein the threshold is a distance from the light source to an opening portion of a casing.

15. The electronic apparatus according to claim 1, wherein the scanning unit is a perforated mirror.

16. The electronic apparatus according to claim 3, wherein

the reflective member is a hexahedral shape that includes the reflective surface and a surface adjacent to a long side of the reflective surface is trapezoidal.

17. The electronic apparatus according to claim 3, wherein

the reflective member is a triangular prism, and

the reflective surface is one side surface of the triangular prism.

18. The electronic apparatus according to claim 3, wherein

the reflective member is a plate-like member that includes the reflective surface, and

a distance from the scanning unit to one short side of the reflective surface of the reflective member is shorter than a distance from the scanning unit to the other short side of the reflective surface.

19. The electronic apparatus according to claim 3, wherein

a distance from the scanning unit to one short side of the reflective surface of the reflective member is shorter than a distance from the scanning unit to the other short side of the reflective surface.

20. A method comprising:

scanning a laser light output by a light source;

reflecting, with a reflective surface of a reflective member, the laser light;

calculating a distance from the light source to the reflective surface using the reflected light; and

determining, based on the calculated distance, a direction in which the laser light is output.