Patent ID: 8094323
Filing Date: 2012-01-10
Classification: G01D

Abstract:
1. An encoder configuration for use in a position sensing device usable to measure a relative position between two elements along a measuring axis direction, the encoder configuration comprising: at least one illumination system including: a scale element including a scale pattern extending along the measuring axis direction, the scale pattern arranged to be illuminated by phosphor light from the phosphor light emitting area and to output a spatially modulated phosphor light pattern along a light path; and a detector electronics comprising a detector portion arranged in a fixed relationship relative to the light generator, and arranged to receive the spatially modulated phosphor light pattern along the light path, wherein the encoder configuration is configured such that: the primary light is distributed to the phosphor area with a first level of primary light intensity uniformity proximate to the phosphor area and the phosphor area outputs the phosphor light with a second level of phosphor light intensity uniformity; and the second level of phosphor light intensity uniformity is more uniform than the first level of primary light intensity uniformity proximate to the phosphor area.