Distance measurement apparatus and distance measurement method

Patent metadata

Field	Value
Publication number	US-10852401-B2
Application number	US-201615752123-A
Country	US
Kind code	B2
Filing date	Jun 6, 2016
Priority date	Sep 2, 2015
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A distance measurement apparatus includes at least one measurement unit. The measurement unit includes a first light reception section including a plurality of photon counting type light reception devices connected to each other and a first conversion section that converts a current outputted from the first light reception section into a voltage. The measurement unit further includes a first amplification section that outputs an amplification value obtained by amplifying the voltage outputted from the first conversion section and outputs, when the amplification value exceeds a given limit value, the limit value as the amplification value. The measurement unit further includes a first measurement section that measures a timing at which the output value from the first amplification section reaches a given threshold value.

First claim

The invention claimed is:

1. A distance measurement apparatus, comprising:
a first measurement unit that includes:
a first light reception section including a plurality of photon counting type light reception devices, wherein
a first photon counting type light reception device of the plurality of photon counting type light reception devices is connected in parallel with a second photon counting type light reception device of the plurality of photon counting type light reception devices, and
the first light reception section is configured to output a first current;

a first conversion section configured to:
convert the first current into a first voltage; and
output the first voltage;

a first amplification section configured to:
output a first amplification value by amplification of the first voltage; and
output, based on the first amplification value that exceeds a first limit value, the first limit value as the first amplification value; and

a first measurement section configured to measure a first timing at which the first amplification value reaches a first threshold value.

2. The distance measurement apparatus according to claim 1 , further comprising a second measurement unit different from the first measurement unit, wherein
the second measurement unit includes:
a second light reception section configured to output a second current;
a second conversion section configured to:
convert the second current into a second voltage; and
output the second voltage; and

a second measurement section configured to measure a second timing at which a value of the second voltage reaches a second threshold value.

3. The distance measurement apparatus according to claim 2 , wherein the second measurement unit further includes:
a second amplification section configured to:
output a second amplification value by amplification of the second voltage; and
output, based on the second amplification value that exceeds a second limit value, the second limit value as the second amplification value.

4. The distance measurement apparatus according to claim 2 , wherein
a measurement target reflects light projected from a light projection section,
the first light reception section is further configured to receive the reflected light, and
the second light reception section is further configured to receive reference light projected from the light projection section.

5. The distance measurement apparatus according to claim 4 , further comprising the light projection section.

6. The distance measurement apparatus according to claim 2 , further comprising:
a calculation section configured to calculate a distance between the distance measurement apparatus and a measurement target based on a difference between the first timing and the second timing.

7. The distance measurement apparatus according to claim 1 , wherein the first light reception section is further configured to:
receive reference light projected from a light projection section; and
receive reflection light based on reflection of light by a measurement target, wherein the light is projected from the light projection section.

8. The distance measurement apparatus according to claim 1 , wherein
the first photon counting type light reception device is configured to receive a first photon and a second photon, and
the first photon counting type light reception device includes a device that does not react based on the second photon that is received within a specific period after the reception of the first photon.

9. A distance measurement method, comprising:
receiving, by a first light reception section, at least one of reference light or reflection light, wherein
the reference light is projected from a light projection section,
the reflection light is based on reflection of light by a measurement target,
the light is projected from the light projection section,
the light reception section includes a plurality of photon counting type light reception devices, and
a first photon counting type light reception device of the plurality of photon counting type light reception devices is connected in parallel with a second photon counting type light reception device of the plurality of photon counting type light reception devices;

outputting, by the light reception section, a current based on the reception of the at least one of the reference light or the reflection light;
converting, by a conversion section, the current into a voltage;
outputting, by the conversion section, the voltage;
outputting, by an amplification section, an amplification value by amplifying the voltage; and
outputting, by the amplification section based on the amplification value that exceeds a limit value, the limit value as the amplification value; and
measuring, by a measurement section, a timing at which the amplification value reaches a threshold value.

10. The distance measurement apparatus according to claim 1 , wherein the first amplification section is a limiting amplifier.

Assignees

• Sony Corp

Inventors

• Koyama Takahiro
• Oohata Toyoharu
• Ono Tomoki

Classifications

• G01C3/06

  Use of electric means to obtain final indication · CPC title

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G01S17/87

  Combinations of systems using electromagnetic waves other than radio waves · CPC title

• G01S7/4865 Primary

  Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) · CPC title