Optical motion encoder with a reflective member allowing the light source and sensor to be on the same side

US6653619B2 · kind B2 · utility

Assignee

• AGILENT TECHNOLOGIES, INC. · US

Inventors

• Yee Loong Chin · Batu Gajah, MY
• Kok Fo · Bukit Mertajam, MY
• Hoo Chong Wong · Kuala Kangsar, MY
• Eric Barton · Eden Prairie, US

Key dates

• Filing date: Sep 12, 2001
• Grant date: Nov 25, 2003
• Expiry date: Feb 20, 2022

Classification

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

Abstract

An optical motion encoder for translation of movement information into a digital output. The optical encoder includes an optical member having a parabolic reflecting surface and a planar surface with a code pattern printed thereon. The light rays received by the parabolic reflecting surface from a light source positioned on the axis of symmetry of the parabolic reflecting surface are reflected as parallel light rays through the planar surface to be modulated by the code pattern and detected by a light detector. In this way, both, the collimator and the code wheel or code strip of prior art optical encoders are represented by a single optical member.