Angular movement detector e.g. for vehicle power assisted steering system has polarized radiation emitter and receiver

摘要

The detector, measuring angular movement between two units (U1, U2) about an axis (X-X), has an emitter (1) with a system for emitting radiation with linear polarization, and a receiver (2) with a polarizer (9) and a photosensitive element (10) to capture the radiation passing through the polarizer. (1) can incorporate a source (4) of polarized light or of non-polarized light and a transformer (5, 6). The detector, designed to measure angular movement between two units (U1, U2) about an axis (X-X), has an emitter (1) with a system for emitting radiation with linear polarization, and a receiver (2) with a polarizer (9) and a photosensitive element (10) to capture the fraction of radiation passing through the polarizer. The emitter can incorporate a source (4) of polarized light or of non-polarized light and a transformer (5, 6) to produce the required polarization, which can be linear, circular or elliptical. In a power assisted steering application the emitter and receiver assemblies are connected mechanically by a tube centered on the axis.