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:
May. 13, 1997
Filed:
Jun. 06, 1995
Daniel B Roitman, Menlo Park, CA (US);
James R Sheats, Palo Alto, CA (US);
Mark R Hueschen, Palo Alto, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An improved electroluminescent device which includes a hole injection electrode, an electron injection electrode, and an electroluminescent layer located between the hole and electron injection electrodes. The electroluminescent layer includes an organic polymer and a hindered phenolic additive in a concentration greater than 4% by weight. The preferred organic polymer is a derivative of PPV. The preferred hindered phenolic additives are and 2,4,6 tri-tert-butyl phenol 2,6 di-tert-butyl-methylphenol. The device has higher efficiency and a slower rate of degradation than devices lacking the hindered phenolic additive.