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Researchers Submit Patent Application, "Organic Electroluminescent Display Device", for Approval

May 8, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors TOKUDA, Naoki (Mobara, JP); Kageyama, Hiroshi (Hachioji, JP); Furuie, Masamitsu (Mobara, JP), filed on December 17, 2013, was made available online on April 24, 2014.

The patent's assignee is Panasonic Liquid Crystal Display Co., Ltd.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to an organic EL display device which uses organic EL elements as pixels, and more particularly to an improved power source wiring which supplies electricity for allowing the organic EL elements to emit light.

"An organic EL element is a current-light-emitting-type element which emits light when an electric current flows therethrough, wherein a large current of several tens to 100 mA flows in a power source line in the inside of a TFT substrate on which the organic EL elements are formed. Particularly, in performing fixed-voltage driving of an EL display panel, when electricity is supplied to respective pixels via the power source line in the inside of the TFT substrate from a terminal at an inlet of the display panel, due to a voltage drop which is generated attributed to the resistance of the power source line, image defects such as the brightness inclination, smears and the like are generated. Accordingly, it is necessary to reduce the resistance of the power source line in the inside of the TFT substrate (from the inlet of the display panel to the respective pixels).

"With respect to the reduction of the power source resistance, in following patent document 1, there is described a technique in which, for lowering a voltage drop attributed to the resistance of a drive power source line which drives a plurality of organic EL elements arranged in a matrix array, auxiliary power source lines are connected to both ends (and an intermediate portion) of a drive power source line.

"Patent document 1: JP-A-2003-108068"

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In the above-mentioned patent document 1, although the voltage drop of the drive power source line which is connected to a plurality of organic EL elements is lowered, a voltage drop of the auxiliary power source lines which are connected to the plurality of drive power source lines is not taken into consideration.

"Accordingly, it is an object of the present invention to provide an organic EL display device which reduces a voltage drop of a power source bus line which supplies electricity to a power source line which is connected to a plurality of organic EL elements.

"The present invention is directed to an organic EL display device which includes a power source line which is connected to a plurality of organic EL elements and a power source bus line which is connected to the power source line, wherein electricity is supplied to a plurality of portions including both ends of the power source bus line or both ends of the power source bus line.

"According to the present invention, it is possible to obtain the organic EL display device which can reduce the voltage drop attributed to the line resistance of the power source bus line which supplies electricity to the power source line of the organic EL elements thus effectively overcoming image defects such as the brightness inclination, smears or the like attributed to the power source bus line.

"The display device according to the present invention is applicable to a TV receiver set, a PC monitor, a notebook type PC, a PDA, a mobile phone, a digital still camera, a digital video camera, a car navigation monitor and the like. Further, the display device according to the present invention is also applicable to other self-luminous light-emitting-type display.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIGS. 1A and 1B are front and cross-sectional general appearance views of an organic EL display device according to the present invention;

"FIG. 2 is a drive circuit diagram of the organic EL display device of an embodiment 1 shown in FIG. 1A;

"FIG. 3 is a detailed view of a pixel made of an organic EL element shown in FIG. 2;

"FIG. 4 is a drive circuit diagram of an organic EL display device of the second embodiment;

"FIG. 5 is a drive circuit diagram of an organic EL display device of the third embodiment;

"FIG. 6 is a drive circuit diagram of an organic EL display device of the fourth embodiment;

"FIG. 7 is a drive circuit diagram of an organic EL display device of the fifth embodiment;

"FIG. 8 is a drive circuit diagram of an organic EL display device of the sixth embodiment; and

"FIG. 9 is a drive circuit diagram of an organic EL display device of the seventh embodiment."

For additional information on this patent application, see: TOKUDA, Naoki; Kageyama, Hiroshi; Furuie, Masamitsu. Organic Electroluminescent Display Device. Filed December 17, 2013 and posted April 24, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5134&p=103&f=G&l=50&d=PG01&S1=20140417.PD.&OS=PD/20140417&RS=PD/20140417

Keywords for this news article include: Panasonic Liquid Crystal Display Co. Ltd.

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Source: Politics & Government Week


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