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:
Dec. 27, 1977
Filed:
Mar. 22, 1976
Applicant:
Inventors:
Yoshijuki Asahara, Kawasaki, JA;
Tetsuro Izumitani, Hino, JA;
Assignee:
Hoya Glass Works, Ltd., Tokyo, JA;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ; C03B / ; C03C / ;
U.S. Cl.
CPC ...
65 3 / ; 65 33 ; 65 3 / ; 65 37 ; 65 6 / ; 65 61 ;
Abstract
Glass-based soft-edged aperture filters having good thermal stability are produced by diffusing a coloring element such as Ag into a glass, thus providing a transmittance gradient in the colored portion thereof. A glass composition comprising a basic glass, such as a silicate, borosilicate or phosphate glass, and 1 to 10% by weight of As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 is especially suitable for producing such soft-edged aperture filters.