Patent · US Active

Measurement system and method utilizing high contrast encoder head for measuring relative movement between objects

US9074911B2 · kind B2 · utility

1Cited by

2References

25Claims

0Family size

Assignee

NIKON CORPORATION · JP

Inventors

Eric Peter Goodwin · Oro Valley, US
Daniel Gene Smith · Tucson, US

Key dates

Filing date	Aug 24, 2012
Grant date	Jul 7, 2015
Priority date	—
Expiry date	Jul 6, 2033

Classification

Technology area (CPC G)Physics
CPC primaryG01D5/38
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A measurement system (22) for measuring the position of a work piece (28) includes a measurement grating (34) and an encoder head (36). The encoder head (36) directs a measurement beam (252) at the measurement grating (34), the measurement beam (252) having an oval shaped cross-section. The encoder head (36) includes a beam shape adjuster (256) positioned in the path of an input measurement beam (240) having a substantially circular cross-sectional shape that transforms the input measurement beam (240) to provide the measurement beam (252) having the oval shaped cross-section.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.