Invention Grant
- Patent Title: Absolute position measurement apparatus and method
- Patent Title (中): 绝对位置测量装置及方法
-
Application No.: US12676002Application Date: 2008-11-18
-
Publication No.: US09043182B2Publication Date: 2015-05-26
- Inventor: Yuzo Seo , Chidane Ouchi , Takao Ukaji
- Applicant: Yuzo Seo , Chidane Ouchi , Takao Ukaji
- Applicant Address: JP Tokyo
- Assignee: Canon Kabushiki Kaisha
- Current Assignee: Canon Kabushiki Kaisha
- Current Assignee Address: JP Tokyo
- Agency: Fitzpatrick, Cella, Harper & Scinto
- Priority: JP2007-302652 20071122
- International Application: PCT/JP2008/071273 WO 20081118
- International Announcement: WO2009/066781 WO 20090528
- Main IPC: G01C9/00
- IPC: G01C9/00 ; G01B9/02

Abstract:
An absolute position measurement apparatus measures an absolute position of an object to be measured using a first light source and a second light source which has coherency lower than that of the first light source. The absolute position measurement apparatus includes a measurement part which measures a point where phases of interference signals from the first and the second light sources coincide with each other or a point where an intensity of the interference signal from the second light source is maximized, an origin defining part which defines the point measured by the measurement part as an origin position, a phase storing part which stores the phase of the interference signal from the first light source at the origin position, an origin redefining part which redefines the origin position, and a position calculating part which calculates the absolute position of the object to be measured.
Public/Granted literature
- US20100235137A1 ABSOLUTE POSITION MEASUREMENT APPARATUS AND METHOD Public/Granted day:2010-09-16
Information query