Patent ID: 7211782
Filing Date: 2007-05-01
Classification: G01D,G02B

Abstract:
1. A precision fiber-optic gauge that senses displacement of a scale grating and outputs all-optical displacement measuring signals, the gauge comprising: a first member comprising a housing that defines a hole; a rotationally alignable member that is received in the hole; a scale grating coupled to a second member that is movable along a measuring axis relative to the first member; and a fiber-optic readhead that is coupled to the first member using the rotationally alignable member, the fiber-optic readhead arranged in an operable position relative to the scale grating, the readhead transmitting light to the scale grating, the readhead comprising at least two fiber-optic detector channels for receiving and spatially filtering light from the scale grating to sense the displacement of the scale grating and outputting all-optical measuring signals based on the received light; wherein; the readhead is coupled to the rotationally alignable member and is capable of being rotationally aligned with respect to the hole about an axis that is nominally perpendicular to the surface of a phase grating that is part of the fiber-optic readhead and capable of being locked in place in relation to the hole at a desired alignment; and the gauge outputs all-optical measuring signals.