Reflective encoder with three-dimensional code carrier

US7358481B2 · kind B2 · utility

Assignee

• Avago General IP Pte Ltd · SG

Inventors

• Theng Hooi Yeoh · Bukit Mertajam, MY
• Hock Aun Tan · Jeniang, MY
• Chee Foo Lum · Bukit Mertajam, MY

Key dates

• Filing date: Mar 6, 2006
• Grant date: Apr 15, 2008
• Expiry date: Mar 6, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/285
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An encoder having a code pattern on a carrier and an emitter detector module is disclosed. The code pattern includes alternating reflective and opaque regions on a carrier that includes a planar surface. The emitter-detector module includes a light source that generates light and directs a portion of the generated light at the first side of the carrier and a first detector that detects light reflected from one of the reflective regions. The reflective regions include a three-dimensional element for directing light from the light source onto the first detector. The element has a surface that is inclined at an oblique angle with respect to the planar surface. The code pattern moves with respect to the emitter-detector module. The three-dimensional element can include a reflective imaging element that images the light source onto a surface of the first detector.