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. 18, 2003
Filed:
Dec. 27, 2001
Shingo Kawashima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An organic electroluminescence (EL) driving circuit and a passive matrix organic EL display device are provided which are capable of decreasing an amount of current required to cause the organic EL element on a scanning line being in a non-selected state to be reverse-biased. The organic EL driving circuit is made up of a plurality of driving sources to feed a driving current from a first power source to a data line to be selected at every scanning timing, a plurality of charging switches to connect all data lines to a voltage holding circuit at an initial stage of scanning timing, a voltage holding circuit to hold each of data lines at a fixed voltage and horizontal driving change-over switches placed on every scanning line in each row and operated to connect selected scanning lines to a ground or to a second power source and to perform switching so as to cause the scanning line being not selected to be in a high impedance state, all of which operate to drive a passive matrix organic EL display panel in which organic EL elements are arranged in row and column directions and in a form of a matrix.