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. 25, 1992
Filed:
Mar. 21, 1991
Akira Kawakatsu, Yokohama, JP;
Toshiba Lighting & Technology Corporation, Tokyo, JP;
Abstract
An automotive lamp comprises a glass bulb having a filament and a light interference film formed on the surface of the glass bulb. The light interference film has a high-refractive index layer and a low-refractive index layer alternately stacked on each other. Each layer has a refractive index ni and a thickness di, wherein i is equal to 1, 2, . . . k. In this case, nidi is equal to (1.+-.0.025)n.sub.2 d.sub.2, wherein i is equal to 3.about.(k-1), n.sub.1 d.sub.1 is equal to (1.+-.0.025)n.sub.2 d.sub.2, and n.sub.k d.sub.k is equal to (1.+-.0.025)n.sub.2 d.sub.2. The maximum value of the reflectance of the film is more than 91% within visible light range, and the 50% transmitting wavelength is from 515 nm to 542 nm.