Invention Grant
- Patent Title: High resolution encoder head
- Patent Title (中): 高分辨率编码器头
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Application No.: US14239773Application Date: 2012-09-05
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Publication No.: US09534934B2Publication Date: 2017-01-03
- Inventor: Eric Peter Goodwin
- Applicant: Eric Peter Goodwin
- Applicant Address: JP
- Assignee: NIKON CORPORATION
- Current Assignee: NIKON CORPORATION
- Current Assignee Address: JP
- Agency: Roeder & Broder LLP
- Agent Steven G. Roeder
- International Application: PCT/US2012/053727 WO 20120905
- International Announcement: WO2013/036498 WO 20130314
- Main IPC: G01D5/34
- IPC: G01D5/34 ; G03F7/20 ; H01L21/67
Abstract:
A measurement system (22) for measuring the position of a work piece (28) along a first axis includes a grating (234), and an encoder head (238) that directs a first measurement beam (240) at the grating (234) at a first angle, and directs a second measurement beam (242) at the grating (234) at a second angle. An absolute value of the first angle relative to a normal (244) of the grating (234) is different from an absolute value of the second angle relative to the normal (244) of the grating (234). Additionally, the first measurement beam (240) has a first wavelength, and the second measurement beam (242) has a second wavelength that can be different from the first wavelength. Further, the first measurement beam (240) and the second measurement beam (242) can impinge at approximately the same location on the grating (234).
Public/Granted literature
- US20140183345A1 HIGH RESOLUTION ENCODER HEAD Public/Granted day:2014-07-03
Information query
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