# US 12,215,968 B2 · Angle measurement device and method

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- Number: US 12,215,968 B2
- Document ID: US12215968B2
- Status: Granted
- Kind: B2
- Application number: 17/925,415
- Filed: 2020-05-19
- Published: 2023-06-15
- Granted: 2025-02-04
- Earliest claimed: 2020-05-19
- Assignees: Nippon Telegraph and Telephone Corporation
- Applicants: Nippon Telegraph and Telephone Corporation
- Inventors: Sohan Kawamura; Takashi Sakamoto; Masahiro Ueno; Yuichi Akage; Soichi Oka
- Web page: https://patentgrep.com/patent/US12215968B2

## CPC

- G01B 11/26: for measuring angles or tapers; for testing the alignment of axes
- G02F 1/29: for the control of the position or the direction of light beams, i.e. deflection
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

An angle measurement device according to the present invention relates to an angle measurement device for measuring an incident angle of an incident light ray, and includes: at least one light deflector; a driving power supply; a light receiver; and a calculation unit. The light deflector is of a transmission type, has an electro-optic effect, and is configured to change an optical path of the light ray by a voltage applied from the driving power supply, and cause the light ray to enter the light receiver. The calculation unit is configured to calculate the incident angle based on the voltage at which an intensity of the light ray detected by the light receiver is maximum.

## Claims

### Claim 1

An angle measurement device for measuring an incident angle of an incident light ray, comprising:
one or more light deflectors which is of a transmission type and has an electro-optic effect;
a driving power supply configured to apply a voltage to the one or more light deflectors;
one or more light receivers; and
a processor, wherein the one or more light deflectors is configured to change an optical path of the incident light ray by the voltage applied from the driving power supply, so as to cause the incident light ray to enter the one or more light receivers, and wherein the processor is configured to calculate the incident angle based on the voltage at which an intensity of the incident light ray detected by the one or more light receivers is maximum.

### Claim 2 (depends on 1)

The angle measurement device according to claim 1, wherein the one or more light deflectors includes a plurality of light deflectors, wherein the plurality of light deflectors are arranged in series, and wherein among the plurality of light deflectors, a deflection direction of a first one of the plurality of light deflectors is different from a deflection direction of a second one of the plurality of light deflectors.

### Claim 3 (depends on 1)

The angle measurement device according to claim 1, wherein the one or more light deflectors includes a plurality of light deflectors arranged in parallel to each other.

### Claim 4 (depends on 1)

The angle measurement device according to claim 1, wherein the one or more light deflectors comprises potassium tantalate niobate.

### Claim 5 (depends on 1)

The angle measurement device according to claim 1, further comprising a baffle plate arranged between a light source of the incident light ray and the one or more light deflectors.

### Claim 6 (depends on 1)

The angle measurement device according to claim 1, further comprising a concave lens arranged between a light source of the incident light ray and the one or more light deflectors.

### Claim 7

An angle measurement method for measuring an incident angle of an incident light ray, using a transmission-type light deflector that has an electro-optic effect, the method comprising:
a step of applying a voltage to one or more light deflectors to change an optical path of the incident light ray;
a step of measuring an intensity of the incident light ray at a predetermined position;
a step of obtaining a peak voltage at which the intensity is maximum; and
a step of calculating the incident angle based on the peak voltage.

### Claim 8 (depends on 7)

The angle measurement method according to claim 7, wherein the one or more light deflectors includes a plurality of light deflectors, wherein the plurality of light deflectors are arranged in series, and wherein among the plurality of light deflectors, a deflection direction of a first one of the plurality of light deflectors is different from a deflection direction of a second one of the plurality of light deflectors.

### Claim 9 (depends on 7)

The angle measurement method according to claim 7, wherein the one or more light deflectors includes a plurality of light deflectors arranged in parallel to each other.

### Claim 10 (depends on 7)

The angle measurement method according to claim 7, wherein the one or more light deflectors comprises potassium tantalate niobate.

### Claim 11 (depends on 7)

The angle measurement method according to claim 7, wherein a baffle plate is arranged between a light source of the incident light ray and the one or more light deflectors.

### Claim 12 (depends on 7)

The angle measurement method according to claim 7, wherein a concave lens is arranged between a light source of the incident light ray and the one or more light deflectors.