# US 9,518,846 B2 · Reflective optical encoder having resin-made code plate

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- Number: US 9,518,846 B2
- Document ID: US9518846B2
- Status: Granted
- Kind: B2
- Application number: 14/590,400
- Filed: 2015-01-06
- Published: 2015-07-30
- Granted: 2016-12-13
- Earliest claimed: 2014-01-24
- Assignees: Fanuc Corporation
- Applicants: Fanuc Corporation
- Inventors: Akinobu Sakata; Nobuyuki Ootake
- Web page: https://patentgrep.com/patent/US9518846B2

## CPC

- G01D 5/34715: {Scale reading or illumination devices}
- G01D 5/34707: {Scales; Discs, e.g. fixation, fabrication, compensation}
- G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR

## Abstract

A reflective optical encoder, which is inexpensive and is compact in the axial direction thereof. An encoder has a generally circular code plate fixed to a rotating body such as a rotation shaft of a motor; and a light emitting unit and a light receiving unit which are positioned near a first major surface of the code plate. The code plate is made from a light transmissive resin, and on the first major surface, an incidence portion with a concavo-convex shape and an emission portion with a concavo-convex shape are formed. On a second major surface opposed to the first major surface, a transmission portion formed from a concavo-convex shape and configured to transmit light, and a total reflection portion formed from a flat surface and configured to totally reflect light, are formed, wherein the transmission portion and the total reflection portion constitute a code pattern section.

## Claims

### Claim 1

A reflective optical encoder comprising:
a code plate which is formed by resin material and has a first major surface and a second major surface opposed to the first major surface;
a light emitting unit positioned near the first major surface of the code plate; and
a light receiving unit positioned near the first major surface of the code plate,
wherein the first major surface of the code plate has:
1) an incidence portion with a concavo-convex shape allowing light transmitted from the light emitting unit to enter the code plate through the first major surface, and
2) an emission portion with a concavo-convex shape allowing the light to exit the code plate through the first major surface, and
wherein the second major surface of the code plate has a code pattern section including:
1) a transmission portion formed from a V-shape, a triangular shape or a curved surface and configured to allow the light to exit the code plate through the second major surface, and
2) a total reflection portion formed from a flat surface and configured to totally reflect the light from the second major surface.

### Claim 2 (depends on 1)

The reflective optical encoder as set forth in claim 1, wherein the concavo-convex shape of the incidence portion is a V-shape or a triangular shape.

### Claim 3 (depends on 1)

The reflective optical encoder as set forth in claim 1, wherein the concavo-convex shape of the incidence portion is a curved shape.

### Claim 4 (depends on 1)

The reflective optical encoder as set forth in claim 1, wherein the concavo-convex shape of the emission portion is a V-shape or a triangular shape.

### Claim 5 (depends on 1)

The reflective optical encoder as set forth in claim 1, wherein the concavo-convex shape of the emission portion is a curved shape.

### Claim 6 (depends on 1)

The reflective optical encoder as set forth in claim 1, wherein the incidence portion and the emission portion are positioned on the first major surface in a configuration that is offset with respect to the positions of the transmission portion and the total reflective portion on the second major surface.