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:
Aug. 15, 1995
Filed:
Feb. 07, 1994
Yoichi Harada, Tokyo, JP;
Seiko Instruments Inc., Tokyo, JP;
Abstract
A spectroscope or spectrometer for detecting a driving position of a main wavelength dispersive device using a diffraction line produced in that light from a light source having a narrow wavelength bandwidth is incident on a sub-wavelength dispersive device in an arrangement that a plane diffraction grating is used as the sub-wavelength dispersive device which is affixed on a driving axis in a manner of forming a suitable angle with the main wavelength dispersive device. When the main wavelength dispersive device is used between 0.degree. and 90.degree. , a diffraction angle of the sub-wavelength dispersive device comes within about 45.degree. . In such a range, the angular dispersion is not changed significantly, thus the interval between diffraction lines is hardly varied. For this reason, the width of a sub-detector can always be set at an optimum condition for raising the positional detecting accuracy while one or more diffraction lines are allowed to be incident.