Invention Application
- Patent Title: FIBER-OPTIC MINIATURE ENCODER FOR FINE PITCH SCALES
- Patent Title (中): 光纤小型编码器,用于细微尺寸
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Application No.: US11461423Application Date: 2006-07-31
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Publication No.: US20080024789A1Publication Date: 2008-01-31
- Inventor: Joseph D. Tobiason , Eric Herbert Altendorf
- Applicant: Joseph D. Tobiason , Eric Herbert Altendorf
- Applicant Address: JP Kawasaki-shi
- Assignee: MITUTOYO CORPORATION
- Current Assignee: MITUTOYO CORPORATION
- Current Assignee Address: JP Kawasaki-shi
- Main IPC: G01B9/02
- IPC: G01B9/02

Abstract:
An ultra-miniature interferometric fiber-optic encoder readhead for sensing displacement of a very fine pitch scale grating is disclosed. The readhead includes a source grating that diffracts diverging source light into ±1st order beams, a pair of mirrors that reflect the ±1st order beams to converge toward the scale grating. The ±1st order scale light beams are reflectively diffracted back from scale grating to return to the mirrors, and are then reflected to converge back toward the light source and a set of adjacent fiber-optic receiver channels. An interference field generating grating positioned in front of the receiver channels produces interference fringes having a desired pitch. Movement of the interference fringes is sensed by the fiber-optic receiver channels to provide displacement information. The readhead may be configured so that primarily or only ±1st order light reaches the receiver channels.
Public/Granted literature
- US07502122B2 Fiber-optic miniature encoder for fine pitch scales Public/Granted day:2009-03-10
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