Optical encoder system including a structured code wheel

摘要

An optical encoder system includes a module that has a light emitting element and a light detecting element, wherein the light detecting element is operable to detect light at a wavelength emitted by the light emitting element. The optical encoder system also includes a code wheel that has facets on its surface. Each facet has a surface that provides diffuse reflectance, with adjacent facets being inclined by different amounts. The code wheel can be disposed with respect to the module so that at least some light emitted by the light emitting element is reflected by the facets back toward the module, wherein an amount of reflected light detected by the light detecting element in the module depends at least in part on the rotational position of the code wheel.

主权项

1. An optical encoder system comprising
a module that includes a light emitting element and a light detecting element, wherein the light detecting element is operable to detect light at a wavelength emitted by the light emitting element; and a code wheel including a plurality of facets on its surface, wherein adjacent facets are inclined by different amounts, each facet having a surface that provides diffuse reflectance, and wherein the facets are comprised of a first group and a second group, wherein the facets alternate between the first and second groups in a direction around a central axis of the code wheel, and wherein the code wheel is disposed with respect to the module so that at least some light emitted by the light emitting element is reflected by the facets back toward the module, wherein an amount of reflected light detected by the light detecting element in the module depends at least in part on the rotational position of the code wheel.