Optical encoder with incremental and absolute code sensors and defining distance between geometric centers of adjacent photosensors of an incremental code sensor

Patent metadata

Field	Value
Publication number	US-10921163-B2
Application number	US-201816053508-A
Country	US
Kind code	B2
Filing date	Aug 2, 2018
Priority date	Jul 31, 2018
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

An optical positioning measurement device includes a light source module operable to emit light, an encoder module and a sensor module. The sensor module is configured to output electric signals relating to luminous flux of light received thereby via the encoder module. The encoder module having a first incremental code portion, a second incremental code portion and an absolute code portion. The first incremental code portion includes multiple first incremental code patterns that are equally distributed. The second incremental code portion includes multiple second incremental code patterns that are equally distributed. The second incremental code patterns are arranged more loosely than the first incremental code patterns.

First claim

What is claimed is:

1. An optical positioning measurement device, comprising:
a light source module operable to emit light;
an encoder module disposed to be illuminated by said light source, and movable relative to said light source module, said encoder module including an encoder body, and further including a first incremental code portion, a second incremental code portion and an absolute code portion that are disposed on said encoder body; and
a sensor module disposed to receive light provided by said light source module via said encoder module, and configured to output electric signal relating to luminous flux of light received thereby, said sensor module including:
a first incremental code sensor unit corresponding in position to said first incremental code portion for receiving light provided via said first incremental code portion, and configured to output a first incremental code signal relating to light received thereby;
a second incremental code sensor unit corresponding in position to said second incremental code portion for receiving light provided via said second incremental code portion, and configured to output a second incremental code signal relating to light received thereby; and
an absolute code sensor unit corresponding in position to said absolute code portion for receiving light provided via said absolute code portion, and configured to output an absolute code signal relating to light received thereby;

wherein said light source module, said encoder module and said sensor module are spaced apart from each other in a first direction; and
said first incremental code portion includes a plurality of first incremental code patterns that are equally distributed along a second direction on said encoder body, and said second incremental code portion includes a plurality of second incremental code patterns that are equally distributed along the second direction on said encoder body, where said second incremental code patterns are arranged more loosely than said first incremental code patterns;
said optical positioning measurement device further comprising a computational controller module electrically connected to said light source module, said absolute code sensor unit, said first incremental code sensor unit and said second incremental code sensor unit for receiving the absolute code signal, the first incremental code signal and the second incremental code signal, respectively, said computational controller module being configured to perform analysis on the absolute code signal, the first incremental code signal and the second incremental code signal to output a positioning signal relating to movement of said encoder module relative to said light source module;
wherein:
said encoder module is rotatably movable around an axis relative to said light source module and said sensor module;
said encoder body surrounds the axis along a circumferential direction, the circumferential direction serving as the second direction;
said first incremental code portion has a plurality of first incremental barcode pattern boundaries that are equiangularly arranged along the circumferential direction by an angular distance of A and that define a plurality of first incremental light barcode elements and a plurality of first incremental dark barcode elements;
arbitrary successive three of said first incremental barcode pattern boundaries cooperatively define one of the first incremental light barcode elements and one of the first incremental dark barcode elements that are adjacent to each other;
each of said first incremental light barcode element is configured to allow the light received thereby from said light source module to reach said first incremental code sensor unit when said first incremental light barcode element is in a sensing zone of said first incremental code sensor unit, and said first incremental dark barcode elements are configured to prevent the light received thereby from said light source module from reaching said first incremental code sensor unit;
said first incremental code sensor unit includes a plurality of first incremental code photo sensors that are equiangularly arranged along the circumferential direction; and
a geometric center of each of said first incremental code photo sensors is spaced apart from that of an adjacent one of said first incremental code photo sensors by an angular distance of A×(N−0.5), where N is a positive integer.

2. The optical positioning measurement device of claim 1 , wherein:
said second incremental code portion has a plurality of second incremental barcode pattern boundaries that are equiangularly arranged along the circumferential direction by an angular distance of 2 A and that define a plurality of second incremental light barcode elements and a plurality of second incremental dark barcode elements;
arbitrary successive three of said second incremental barcode pattern boundaries cooperatively define one of the second incremental light barcode elements and one of the second incremental dark barcode elements that are adjacent to each other;
each of said second incremental light barcode elements is configured to allow the light received thereby from said light source module to reach said second incremental code sensor unit when said second incremental light barcode element is in a sensing zone of said second incremental code sensor unit, and said second incremental dark barcode elements are configured to prevent the light received thereby from said light source module from reaching said second incremental code sensor unit;
said second incremental code sensor unit includes a plurality of second incremental code photo sensors that are equiangularly arranged along the circumferential direction; and
a geometric center of each of said second incremental code photo sensors is spaced apart from that of an adjacent one of said second incremental code photo sensors by an angular distance of 2 A×(N−0.5).

3. The optical positioning measurement device of claim 2 , wherein:
said absolute code portion has a plurality of absolute barcode pattern boundaries that are angularly spaced apart from each other along the circumferential direction and that define a plurality of absolute light barcode elements and a plurality of absolute dark barcode elements;
arbitrary successive three of said absolute barcode pattern boundaries cooperatively define one of the absolute light barcode elements and one of the absolute dark barcode elements that are adjacent to each other;
each of said absolute light barcode elements is configured to allow the light received thereby from said light source module to reach said absolute code sensor unit when said absolute light barcode element is in a sensing zone of said absolute code sensor unit, and said second incremental dark barcode elements are configured to prevent the light received thereby from said light source module from reaching said absolute code sensor unit;
said absolute code sensor unit includes a plurality of absolute code photo sensors that are equiangularly arranged along the circumferential direction; and
a geometric center of each of said absolute code photo sensors is spaced apart from that of an adjacent one of said absolute code photo sensors by an angular distance of 2 A.

4. The optical positioning measurement device of claim 3 , wherein:
said light source module and said sensor module are disposed at opposite sides of said encoder module;
said encoder body is made of a light-transmissible material;
each of said first incremental light barcode elements, said second incremental light barcode elements and said absolute light barcode elements is made of a light-transmissible material;
each of said first incremental dark barcode elements, said second incremental dark barcode elements and said absolute dark barcode elements is made

Assignees

• Hiwin Mikrosystem Corp

Inventors

• Hsiao Heng-Sheng
• Chen Yin-Yuan
• Chen Tsan-Lin

Classifications

• G01D5/34792 Primary

  with only digital scales or both digital and incremental scales · CPC title

• G01D5/34715

  Scale reading or illumination devices · CPC title

• G01D5/3473

  Circular or rotary encoders · CPC title