Inclination detector, line-of-sight detection device, retinal projection display device, head-mounted display device, optometric device, virtual-reality display apparatus, user-condition estimation apparatus, driver-assistance system, method of detecting degree of inclination of three-dimensional object, and method of detecting line-of-sight

Patent metadata

Field	Value
Publication number	US-12517581-B2
Application number	US-202218708697-A
Country	US
Kind code	B2
Filing date	Dec 8, 2022
Priority date	Dec 23, 2021
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

An inclination detector includes: multiple light emitters configured to emit multiple beams to an object: a photosensor having a light-receiving surface; and an output unit. The photosensor is configured to receive the multiple beams reflected from the object on the light-receiving surface and output an electrical signal based on light intensity of the multiple beams received on the light-receiving surface. The output unit configured to output a result of detection of a degree of inclination of the object based on the electrical signal output from the photosensor. The photosensor is disposed at a position at which the light intensity of the multiple beams that are emitted from the multiple light emitters, reflected at the object, and received at the photosensor changes according to the degree of inclination of the object.

First claim

The invention claimed is:

1 . An inclination detector, comprising:
multiple light emitters to emit multiple beams to an object; a photosensor having a light-receiving surface to: receive the multiple beams reflected from the object on the light-receiving surface; and output an electrical signal based on light intensity of the multiple beams received on the light-receiving surface; and output circuitry configured to output a result of detection of a degree of inclination of the object based on the electrical signal output from the photosensor, wherein the photosensor is disposed at a position at which the light intensity of the multiple beams that are emitted from the multiple light emitters, reflected at the object, and received at the photosensor changes according to the degree of the inclination of the object, wherein a conditional expression below is satisfied:

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h
-

w
/
2

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≤
d
≤

h
+

w
/
2

where
w is a width of the light-receiving surface of the photosensor in a predetermined direction,
d is a center-to-center distance between adjacent beams of the multiple beams on the light-receiving surface, and
h is a radius of each of the beams on the light-receiving surface.

2 . The inclination detector according to claim 1 ,
wherein the multiple light emitters emit multiple beams in parallel.

3 . The inclination detector according to claim 1 ,
wherein the multiple light emitters are at equal intervals in a predetermined direction along a light-emitting surface of the multiple light emitters.

4 . The inclination detector according to claim 1 ,
wherein the multiple light emitters are disposed in each of two different directions along a light-emitting surface of the multiple light emitters.

5 . The inclination detector according to claim 1 , wherein:
the multiple light emitters are at intervals in predetermined directions along a light-emitting surface of the multiple light emitters, and each of the intervals is shorter than a length of a light-receiving surface of the photosensor in the predetermined directions.

6 . The inclination detector according to claim 1 ,
wherein the beams reflected from the object diverge toward the photosensor.

7 . The inclination detector according to claim 1 ,
wherein a diameter of the beams reflected from the object is longer than a length of the light-receiving surface of the photosensor in a predetermined direction.

8 . The inclination detector according to claim 1 , further comprising:
control circuitry configured to control the multiple light emitters to emit beams time-modulated by a code having orthogonality, wherein the output circuitry separately detects the time-modulated beams based on the electrical signal output from the photosensor.

9 . The inclination detector according to claim 8 ,
wherein the code is a Hadamard code.

10 . The inclination detector according to claim 8 , wherein:
the multiple light emitters are divided into multiple groups, and the control circuitry controls the multiple light emitters to emit beams on a group-by-group basis.

11 . A line-of sight detection device comprising:
the inclination detector according to claim 1 configured to detect a line of sight of an eyeball as the object based on the result of detection of the degree of the inclination of the object.

12 . A retina projection display comprising the line-of-sight detection device according to claim 11 .

13 . A head-mounted display device comprising the line-of-sight detection device according to claim 11 .

14 . A virtual-reality display apparatus comprising the line-of-sight detection device according to claim 11 .

15 . A user-condition estimation device comprising:
the line-of-sight detection device according to claim 11 configured to detect a line-of-sight direction; and condition estimation circuitry configured to estimate a condition of a user based on information on the line-of-sight direction detected by the line-of-sight detection device.

16 . The user-condition estimation device according to claim 15 , wherein:
the condition estimation circuitry estimates the condition of the user based on frequency of occurrence of micro vibration of the eyeball.

17 . The user-condition estimation device according to claim 15 , wherein:
the condition of the user includes at least one of fatigue level or attention level of the user.

18 . A driver-assistance system comprising:
the user-condition estimation device according to claim 15 ; and operation control circuitry configured to control an operation of a mobile object driven by a user based on the condition estimated by the user-condition estimation device.

19 . A method of detecting a line-of-sight, comprising:
emitting multiple beams to an object, using multiple light emitters; receiving the multiple beams reflected from the object on a light-receiving surface of a photosensor; outputting an electrical signal based on light intensity of the multiple beams received on the light-receiving surface; and outputting a result of detection of a degree of inclination of the object based on the electrical signal output from the photosensor, wherein the photosensor is disposed at a position at which the light intensity of the multiple beams that are emitted from the multiple light emitters, reflected at the object, and received at the photosensor changes according to the degree of the inclination of the object, wherein a conditional expression below is satisfied:
| h−w/ 2|≤ d≤h+w/ 2

where w is a width of the light-receiving surface of the photosensor in a predetermined direction, d is a center-to-center distance between adjacent beams of the multiple beams on the light-receiving surface, and h is a radius of each of the beams on the light-receiving surface.

20 . The method according to claim 19 , wherein:
the emitting multiple beams emit the multiple beams in parallel.

21 . An inclination detector, comprising:
multiple light emitters to emit multiple beams to an object; a photosensor having a light-receiving surface to: receive the multiple beams reflected from the object on the light-receiving surface; and output an electrical signal based on light intensity of the multiple beams received on the light-receiving surface; and output circuitry configured to output a result of detection of a degree of inclination of the object based on the electrical signal output from the photosensor, wherein the photosensor is disposed at a position at which the light intensity of the multiple beams that are emitted from the multiple light emitters, reflected at the object, and received at the photosensor changes according to the degree of the inclination of the object, the inclination detector further com

Assignees

• Yoshikawa Masato
• Sangu Suguru
• Yoshida Saori
• Ricoh Co Ltd

Inventors

• Yoshikawa Masato
• Sangu Suguru
• Yoshida Saori

Classifications

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G06F3/013 Primary

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title