Optical displacement sensor and torque sensor employing relatively movable slit patterns

USRE37969E1 · kind E1 · reissue

Assignee

• TRW Lucas Varity Electric Steering Limited · GB

Inventors

• Steven John Horton · Solihull, GB
• Adrian Leslie Trace · Birmingham, GB
• David B. Rees · Dudley, GB

Key dates

• Filing date: Nov 21, 2000
• Grant date: Jan 28, 2003
• Expiry date: Nov 21, 2020

Classification

• Technology area (CPC —): General

Abstract

An optical displacement sensor is used to measure the rotary displacement between two shafts which rotate together. By connecting the shafts together by means of a torsion bar, the sensor may be used to measure transmitted torque. The sensor comprises first and second coaxial discs mounted on the shafts and having slots formed therein. A light source directs light through the slots onto an array of photodetectors and a data processor determines the displacement or torque from the positions on the array of images of the slot edges.