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:
Feb. 02, 1982
Filed:
Jan. 15, 1981
Abstract
A red emission fluorescent display device employing improved SnO.sub.2 :Eu phosphor as a low-energy-electron excitation phosphor. The phosphor is manufactured by the following steps: An aqueous solution of a mixture of europium and at least one material selected from stannous halides and stannous sulfate is prepared. The amount of europium ion is adjusted so that the ratio thereof to tin ions ranges between 5.times.10.sup.-2 and 10 atomic %. The solution is poured into and mixed with a hot aqueous solution including oxalic ions, while the mixed solution is being stirred, to form oxalate coprecipitates of tin and europium. After being dryed the coprecipitate is heated so as to be thermally decomposed and then is subjected to heat treatment at the temperature above that for the thermal decomposition, whereby europium ions are diffused into the stannic oxide matrix. The device exhibits remarkably high luminescence intensity which is satisfactory for practical use.