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:
Jan. 08, 1991
Filed:
Jun. 22, 1989
Applicant:
Inventors:
Tatsuo Harada, Fuchu, JP;
Toshiei Kurosaki, Kodaira, JP;
Toshiaki Kita, Tokyo, JP;
Tsuneo Terasawa, Hachioji, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
356328 ; 355 53 ; 372 32 ; 372 57 ;
Abstract
A spectrometer is disclosed, in which plural entrance slits are mounted, and a reference light passing through one entrance slit and the light to be measured passing through the other entrance slit are simultaneously focused on a photo-sensitive surface of a detector through a diffraction grating and a focusing optical system, to measure the wavelength of the light to be measured precisely by using the reference light as a standard.