Patent ID: 9689715
Date: 2017-06-27
CPC Classifications: G01D

Claim:
1. A light source array used in an illumination portion of 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 light source array comprises individual sources arranged in an approximately planar two-dimensional (2D) grid pattern and located to coincide with a set of first grid pattern lines parallel to a first grid axis, and furthermore located to coincide with a set of second grid pattern lines parallel to a second grid axis that is transverse to the first grid axis; members of the set of first grid pattern lines are spaced apart by a first grid line pitch P the light source array is configured to be mounted with a first rotational orientation about an axis normal to the 2D grid pattern in a first illumination portion for use with a scale grating having a first scale grating pitch SGP the light source array is furthermore configured to be mounted with a second rotational orientation about an axis normal to the 2D grid pattern in a second illumination portion for use with a scale grating having a second scale grating pitch SGP the first illumination source line pitch IP