Optical assembly for three-dimensional measurement device and three-dimensional measurement device equipped with same

Patent metadata

Field	Value
Publication number	US-2022397739-A1
Application number	US-202017635383-A
Country	US
Kind code	A1
Filing date	Aug 28, 2020
Priority date	Sep 5, 2019
Publication date	Dec 15, 2022
Grant date	—

Abstract

An optical assembly (13) for a three-dimensional measurement device is equipped with: an optical lens (320) that forms a pair of conjugate planes having an optically conjugate relationship; an optical device (341) that is disposed on one of the pair of conjugate planes; a temperature sensor (354) for detecting the temperature of the optical lens (320); a heater (350) for heating the optical lens (320); and a control part that controls the operation of the heater (350) on the basis of the result of the detection made by the temperature sensor (354) such that the optical lens (320) reaches a constant temperature.

First claim

1 . An optical assembly for a three-dimensional measurement device comprising:
an optical lens configured to form a pair of conjugate planes having an optically conjugate relationship; an optical device that is disposed on one of the pair of conjugate planes; a temperature sensor configured to detect a temperature of the optical lens; a heater configured to heat the optical lens; and a control part configured to control an operation of the heater based on a detection result of the temperature sensor such that the optical lens has a constant temperature.

2 . The optical assembly for a three-dimensional measurement device according to claim 1 , further comprising:
a lens support part configured to surround the optical lens in a direction orthogonal to an optical axis of the optical lens to support the optical lens, wherein the temperature sensor and the heater are assembled to the lens support part.

3 . The optical assembly for a three-dimensional measurement device according to claim 2 , further comprising:
a cover member configured to surround the lens support part and cover the temperature sensor and the heater, wherein a thermal conductivity of the cover member is equal to or lower than a thermal conductivity of the lens support part.

4 . The optical assembly for a three-dimensional measurement device according to claim 3 ,
wherein the lens support part has a lens barrel configured to support the optical lens and a mount member to which the lens barrel is fixed, and wherein the cover member has a substantially sealed structure in which the mount member is concealed.

5 . The optical assembly for a three-dimensional measurement device according to claim 4 ,
wherein an air layer is provided in at least a portion between the cover member and the mount member.

6 . The optical assembly for a three-dimensional measurement device according to claim 2 , further comprising:
a base part to which the lens support part is fixed, wherein a thermal conductivity of the base part is equal to or lower than the thermal conductivity of the lens support part.

7 . The optical assembly for a three-dimensional measurement device according to claim 2 ,
wherein the heater is configured as a flexible heater composed of a flexible board on which a heating wire is provided, wherein the temperature sensor is mounted on the flexible board, and wherein the flexible heater is disposed on an outer circumferential surface of the lens support part.

8 . The optical assembly for a three-dimensional measurement device according to claim 7 ,
wherein the flexible heater is attached to the lens support part using an adhesive tape having a high thermal conductivity.

9 . The optical assembly for a three-dimensional measurement device according to claim 1 ,
wherein the optical device is composed of a pattern lighting forming element configured to form pattern lighting, and wherein the optical lens is composed of a light projection lens for forming an image of a projection pattern by projecting the pattern lighting onto a subject disposed on the other of the pair of conjugate planes.

10 . The optical assembly for a three-dimensional measurement device according to claim 9 ,
wherein the constant temperature is a temperature equal to or higher than a highest temperature that the light projection lens is able to reach when the heater does not heat the light projection lens within a range of a surrounding environment temperature in which use of the optical assembly for a three-dimensional measurement device is allowed and lower than or equal to an upper limit of an operation-guaranteed temperature of the pattern lighting forming element.

11 . The optical assembly for a three-dimensional measurement device according to claim 1 ,
wherein the optical device is composed of an image sensor that has a focal plane, and wherein the optical lens is composed of a light receiving lens for forming, on the focal plane, an image of a projection pattern projected onto a subject disposed on the other of the pair of conjugate planes.

12 . The optical assembly for a three-dimensional measurement device according to claim 11 ,
wherein the constant temperature is a temperature equal to or higher than a highest temperature that the light receiving lens is able to reach when the heater does not heat the light receiving lens within a range of a surrounding environment temperature in which use of the optical assembly for a three-dimensional measurement device is allowed and lower than or equal to an upper limit of an operation-guaranteed temperature of the image sensor.

13 . A three-dimensional measurement device, comprising:
an optical assembly for a three-dimensional measurement device as a projection part, the optical assembly comprising:
an optical lens configured to form a pair of conjugate planes having an optically conjugate relationship;
an optical device that is disposed on one of the pair of conjugate planes;
a temperature sensor configured to detect a temperature of the optical lens:
a heater configured to heat the optical lens; and
a control part configured to control an operation of the heater based on a detection result of the temperature sensor such that the optical lens has a constant temperature,
wherein the optical device is composed of a pattern lighting forming element configured to form pattern lighting, and
wherein the optical lens is composed of a light projection lens for forming an image of a projection pattern by projecting the pattern lighting onto a subject disposed on the other of the pair of conjugate planes; and
the optical assembly for a three-dimensional measurement device according to claim 11 as an imaging part.

14 . A three-dimensional measurement device, comprising:
an optical assembly for a three-dimensional measurement device as a projection part, the optical assembly comprising:
an optical lens configured to form a pair of conjugate planes having an optically conjugate relationship;
an optical device that is disposed on one of the pair of conjugate planes;
a temperature sensor configured to detect a temperature of the optical lens;
a heater configured to heat the optical lens; and
a control part configured to control an operation of the heater based on a detection result of the temperature sensor such that the optical lens has a constant temperature,
wherein the optical device is composed of a pattern lighting forming element configured to form pattern lighting, and
wherein the optical lens is composed of a light projection lens for forming an image of a projection pattern by projecting the pattern lighting onto a subject disposed on the other of the pair of conjugate planes; and
the optical assembly for a three-dimensional measurement device according to claim 12 as an imaging part.

15 . A three-dimensional measurement device, comprising:
an optical assembly for a three-dimensional measurement device as a projection part, the optical assembly comprising:
an optical lens configured to form a pair of conjugate planes having an optically conjugate relationship;
an optical device that is disposed on one of the pair of conjugate planes;
a temperature sensor configured to detect a temperature of the optical lens;
a heater configured to heat the optical lens; and
a control part configured to control an operation of the heater based on a detection result of the temperature sensor such that the optical lens has a constant temperature,
wherein the optical device is composed of a pattern lighting forming element configured to form pattern lighting,
wherein the

Assignees

• Omron Tateisi Electronics Co

Inventors

• Inoda Takeshi
• Ariyoshi Tomonori
• Nakatsuka Hitoshi
• Okuno Motoharu
• Matsumoto Shinya
• Ota Jun
• Kiguchi Tetsuya

Classifications

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title

• G03B17/55 Primary

  with provision for heating or cooling, e.g. in aircraft · CPC title

• H04N23/52

  Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements · CPC title

• G01B11/2513

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title