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:
Mar. 22, 1977
Filed:
Aug. 27, 1973
Carl F Swinehart, University Heights, OH (US);
Herbert Packer, Cleveland Heights, OH (US);
The Harshaw Chemical Company, Cleveland, OH (US);
Abstract
A hot-pressed optical body is disclosed which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable powder, and either hot-pressing or extruding the powder.