Optical scanning device, imaging device, and distance measurement device

Patent metadata

Field	Value
Publication number	US-11240402-B2
Application number	US-201815869830-A
Country	US
Kind code	B2
Filing date	Jan 12, 2018
Priority date	Jan 19, 2017
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

An optical scanning device for displaying or capturing an image is used, the device including: an optical scanning unit configured to scan emitted light while drawing a spiral trajectory, wherein the unit includes: a light guide path configured to guide incident light to output the emitted light from an emission end; and a vibration unit configured to vibrate the emission end; a light emission control unit configured to control light emission of the emitted light; a polar coordinate generation unit configured to generate a radius and a deflection angle relating to the spiral trajectory; a driving signal generation unit configured to generate a driving signal for driving the vibration unit; an angle correction unit configured to perform calculation for correcting an angle based on information from the driving signal generation unit and output an corrected angle; and a coordinate calculation unit configured to calculate coordinates of an image.

First claim

The invention claimed is:

1. An optical scanning device for displaying or capturing an image, the optical scanning device comprising:
an optical scanning unit configured to scan emitted light while drawing a spiral trajectory, the optical scanning unit including:
a light guide path configured to guide incident light to output the emitted light from an emission end; and
a vibration unit configured to vibrate the emission end;

a light emission control unit configured to control light emission of the emitted light;
a polar coordinate generation unit configured to generate a radius r drv and a deflection angle relating to the spiral trajectory;
a driving signal generation unit configured to generate a driving signal for driving the vibration unit by using the radius r drv and the deflection angle;
an angle correction unit configured to perform calculation for correcting an angle based on information from the driving signal generation unit and output a corrected angle θ calc ; and
a coordinate calculation unit configured to calculate coordinates of an image by using the radius r drv and the corrected angle and output image coordinates; and
when a(r) and b(r) are functions having raw as an argument, the coordinate calculation unit outputs a result calculated by using a(r)·r drv ·cos(θ calc ) as an x-coordinate of the image coordinates and outputs a result calculated by using b(r)·r drv ·sin(θ calc ) as a y-coordinate of the image coordinates.

2. The optical scanning device according to claim 1 , wherein, when the deflection angle is θ drv and f(r) is a function having the radius raw as an argument,
the angle correction unit outputs the corrected angle θ calc so as to satisfy formula (1):
θ calc =θ drv +ƒ( r drv )  formula (1).

3. The optical scanning device according to claim 1 , wherein the optical scanning device comprises a display image storage unit configured to store a display image, and
the light emission control unit control the light emission of the emitted light based on the image coordinates output by the coordinate calculation unit and information read from the display image storage unit.

4. The optical scanning device according to claim 1 , wherein the optical scanning device comprises:
a light receiving unit configured to detect return light of the emitted light emitted from the emission end of the light guide path; and
a captured image storage unit configured to store a captured image,
wherein the captured image storage unit stores information on the return light detected by the light receiving unit, based on the image coordinates output by the coordinate calculation unit.

5. The optical scanning device according to claim 1 , wherein the optical scanning device comprises:
a light receiving unit configured to detect return light of the emitted light emitted from the emission end of the light guide path; and
a captured image storage unit configured to store a captured image,
wherein information stored in the captured image storage unit is a value obtained by performing predetermined processing on information on the return light detected by the light receiving unit.

6. The optical scanning device according to claim 1 , wherein the optical scanning device comprises:
a light receiving unit configured to detect return light of the emitted light emitted from the emission end of the light guide path; and
a captured image storage unit configured to store a captured image,
wherein information stored in the captured image storage unit is a value obtained by performing predetermined processing on information on the return light detected by the light receiving unit over a period in which the spiral trajectory is drawn a predetermined number of times.

7. The optical scanning device according to claim 4 , wherein the information on the return light is a light amount of the return light detected by the light receiving unit.

8. The optical scanning device according to claim 4 , wherein the light receiving unit outputs a current in proportion to a light amount of the return light, and
information on the return light is a current value of the current outputted by the light receiving unit.

9. The optical scanning device according to claim 4 , wherein the optical scanning device comprises a distance measurement unit configured to measure a distance by using an output signal of the light emission control unit and an output signal of the light receiving unit, and
information on the return light is distance information measured by the distance measurement unit.

Assignees

• Hitachi Ltd

Inventors

• Onoe Shinsuke
• Nakamura Toshiteru
• Yamada Kenichiro
• Matsuda Takahiro
• Seo Yoshiho

Classifications

• G01S17/42 Primary

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

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• G02B6/4206

  Optical features (G02B6/4207, G02B6/421 take precedence) · CPC title

• G02B26/10 Primary

  Scanning systems · CPC title

• G02B6/4215

  the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence) · CPC title