Encoder, robot, and printer

Patent metadata

Field	Value
Publication number	US-2019121323-A1
Application number	US-201816167946-A
Country	US
Kind code	A1
Filing date	Oct 23, 2018
Priority date	Oct 24, 2017
Publication date	Apr 25, 2019
Grant date	—

Abstract

An encoder includes a base portion, a scale portion that is provided to be relatively rotatable with respect to the base portion, and has a plurality of marks, an imaging element that is disposed in the base portion, and images the marks, and an estimation portion that performs template matching on a captured image in the imaging element by using a reference image, in which the plurality of marks include a first mark and a second mark, and the estimation portion counts the number of pixels of the imaging element corresponding to a rotation angle of the scale portion with respect to the base portion until a position of the second mark is detected from detection of a position of the first mark, and performs calibration on the basis of the counted number of pixels and the rotation angle.

First claim

What is claimed is:

1 . An encoder comprising:
a base portion; a scale portion that is provided to be relatively movable or rotatable with respect to the base portion, and has a plurality of marks including a first mark and a second mark; an imaging element that is disposed in the base portion, and images the marks; and an estimation portion that performs template matching on a captured image in the imaging element by using a reference image, so as to detect positions of the marks, and estimates a movement state or a rotation state of the scale portion with respect to the base portion, wherein the estimation portion counts the number of pixels of the imaging element corresponding to a movement amount or a rotation angle of the scale portion with respect to the base portion until a position of the second mark is detected from detection of a position of the first mark, and performs calibration on the basis of the counted number of pixels and the movement amount or the rotation angle.

2 . The encoder according to claim 1 ,
wherein the scale portion is relatively rotatable with respect to the base portion.

3 . The encoder according to claim 1 , further comprising:
a storage portion that stores an absolute position or an absolute angle of at least one of the first mark and the second mark with respect to the base portion.

4 . An encoder comprising:
a base portion; a scale portion that is provided to be relatively movable or rotatable with respect to the base portion, and has a plurality of marks including a first mark; an imaging element that is disposed in the base portion, and images the marks; and an estimation portion that performs template matching on a captured image in the imaging element by using a reference image, so as to detect positions of the marks, and estimates a rotation state of the scale portion with respect to the base portion, wherein the estimation portion counts the number of pixels of the imaging element until a position of the first mark is detected next after the scale portion is rotated by 360° with respect to the base portion from detection of a position of the first mark, and performs calibration on the basis of the counted number of pixels and the rotation angle of 360°.

5 . A robot comprising:
the encoder according to claim 1 ; a first member; and a second member that is provided to be rotatable with respect to the first member; wherein the encoder detects a rotation state of the second member with respect to the first member.

6 . A robot comprising:
the encoder according to claim 2 ; a first member; and a second member that is provided to be rotatable with respect to the first member; wherein the encoder detects a rotation state of the second member with respect to the first member.

7 . A robot comprising:
the encoder according to claim 3 ; a first member; and a second member that is provided to be rotatable with respect to the first member; wherein the encoder detects a rotation state of the second member with respect to the first member.

8 . A robot comprising:
the encoder according to claim 4 ; a first member; and a second member that is provided to be rotatable with respect to the first member; wherein the encoder detects a rotation state of the second member with respect to the first member.

9 . The robot according to claim 5 , further comprising:
a decelerator that delivers drive force to the second member side from the first member side, wherein the scale portion is connected to the second member.

10 . A printer comprising the encoder according to claim 1 .

11 . A printer comprising the encoder according to claim 2 .

12 . A printer comprising the encoder according to claim 3 .

13 . A printer comprising the encoder according to claim 4 .

Assignees

• Seiko Epson Corp

Inventors

• Tokushima Daiki
• Kondo Takayuki

Classifications

• B25J13/088

  with position, velocity or acceleration sensors · CPC title

• G05B2219/37555

  Camera detects orientation, position workpiece, points of workpiece · CPC title

• G01D5/34776

  Absolute encoders with analogue or digital scales · CPC title

• G01D5/00 Primary

  Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable (G01D3/00 takes precedence; specially adapted for apparatus giving results other than momentary value of variable G01D1/00) · CPC title

• B25J9/1692

  Calibration of manipulator · CPC title