Illumination portion for an optical encoder

摘要

An illumination portion for an optical encoder is disclosed. The optical encoder comprises the illumination portion, a scale grating extending along a measuring axis direction and arranged to receive light from the illumination portion, and a detector configuration arranged to receive light from the scale grating. The illumination portion comprises an addressable light source array. The addressable light source array comprises individual sources arranged along the measuring axis direction. The addressable light source array is configured to provide at least a first addressable set and a second addressable set of the individual sources.

主权项

1. An illumination portion for an optical encoder which comprises the illumination portion, a scale grating extending along a measuring axis direction and arranged to receive light from the illumination portion, and a detector configuration arranged to receive light from the scale grating, wherein:
the illumination portion comprises an addressable light source array; at least one of the scale grating or the addressable light source array is configured to move relative to the other along the measuring axis direction; the addressable light source array comprises individual sources arranged along the measuring axis direction; the addressable light source array is configured to provide at least first and second addressable sets of the individual sources, the first addressable set including a first plurality of the individual sources arranged along the measuring axis direction, and the second addressable set including a second plurality of the individual sources arranged along the measuring axis direction; the individual sources of the first addressable set of the individual sources are arranged periodically along the measuring axis direction having a first pitch P1; and the individual sources of the second addressable set of the individual sources are arranged periodically along the measuring axis direction having a second pitch P2 that is different than the first pitch P1.