Optical projection encoder with patterned mask

US7378643B2 · kind B2 · utility

Assignee

• Avago Technologies General IP Pte. Ltd · SG

Inventors

• Chee Foo Lum · Bukit Mertajam, MY
• Sai Mun Lee · Kampung Bukit Kechil, MY
• Weng Fei Wong · Bukit Mertajam, MY

Key dates

• Filing date: Apr 24, 2006
• Grant date: May 27, 2008
• Expiry date: May 19, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/34715
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An Optical Projecting Encoder (“OPE”) having an emitter module for transmitting emitted optical radiation through a mask to a moving object, and a detector module for receiving reflected optical radiation from the moving object. The reflected optical radiation from the moving object may include a predetermined image cast by the mask and a surface texture image from the moving object. The OPE may include a transmissive layer covering both the emitter module and the detector module, where the transmissive layer covering the emitter module collimates the optical radiation from the emitter module, and the transmissive layer covering the detector module concentrates the optical radiation reflected from the moving object to the detector module. The detector module may include an optical navigation sensor that continuously acquires and compares predetermined images cast by the mask and surface texture images from the moving object.