Optical encoder module

US7279674B2 · kind B2 · utility

Assignee

• Avago Technologies ECBU IP (Singapore) Pte. Ltd. · SG

Inventors

• Kee Yean Ng · Bukit Mertajam, MY
• Kok Fo · Bukit Mertajam, MY
• Yee Loong Chin · Batu Gajah, MY
• Chee-Keong Chong · Merang, MY
• Chin Lee · Bukit Mertajam, MY

Key dates

• Filing date: Aug 15, 2001
• Grant date: Oct 9, 2007
• Expiry date: Apr 4, 2023

Classification

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

Abstract

An optical encoder module is employed to detect light modulated by a moveable member (e.g., code wheel). The optical encoder includes an emitter having a light-emitting element, and a transparent medium encapsulating the light-emitting element. The transparent medium has a convex aspherical external surface shaped so as to focus light received from the light-emitting element into a substantially collimated beam of light using a single refractive interface for illuminating the movable member. The optical encode module also includes a detector facing the emitter for detecting modulated light of the collimated beam transmitted through the movable member.