The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 2005
Filed:
Sep. 04, 2002
Shin Yasuda, Ashigarakami-gun, JP;
Katsunori Kawano, Ashigarakami-gun, JP;
Jiro Minabe, Ashigarakami-gun, JP;
Tatsuya Maruyama, Ashigarakami-gun, JP;
Masaaki Shimizu, Ashigarakami-gun, JP;
Shin Yasuda, Ashigarakami-gun, JP;
Katsunori Kawano, Ashigarakami-gun, JP;
Jiro Minabe, Ashigarakami-gun, JP;
Tatsuya Maruyama, Ashigarakami-gun, JP;
Masaaki Shimizu, Ashigarakami-gun, JP;
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
Laser light output from a laser light source is irradiated onto a transmission-type scale. Due to movement of the transmission-type scale, a polarization angle of transmitted light varies in accordance with variations in orientations of half-wave plates arrayed in a longitudinal direction. It is difficult for the polarization angle to be affected by noise factors such as external light or the like. Light intensity of a polarized light component, which is transmitted through an analyzer and detected at a photo-detector, varies in accordance with the polarization angle. Thus, the light intensity varies as the transmission-type scale moves, and a detection signal is output to a movement amount computing device. When an amount of movement is computed on the basis of the signal, the exact amount of movement can be detected.