News Column

Patent Application Titled "Organic Light Emitting Devices" Published Online

June 5, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors LEE, Gae-hwang (Seongnam-si, KR); SHIM, Hong-shik (Seoul, KR), filed on October 24, 2013, was made available online on May 22, 2014.

The assignee for this patent application is Samsung Corning Precision Materials Co., Ltd.

Reporters obtained the following quote from the background information supplied by the inventors: "Example embodiments relate to organic light emitting devices (OLED) having resonant structures with wider viewing angles.

"An organic light emitting device (OLED) includes an anode electrode, an organic light emitting layer, and a cathode electrode. As electric current flows through the organic light emitting layer, electrons and holes move to the organic light emitting layer through an electron transport layer and a hole transport layer. The electrons and the holes recombine to emit light.

"Unlike a light emitting diode (LED), surface emission is possible in OLEDS, and thus, OLEDS may be used in displays and illuminators. An organic light emitting display, which has adopted the OLED, is a self light-emitting type and does not need a separate light source. Thus, an organic light emitting display may be formed slimmer and lighter when compared to a cathode ray tube (CRT) or a liquid crystal display (LCD), have shorter response time and consume less power. Further, OLEDs have a simpler structure, and thus, may be more easily manufactured. However, OLEDs radiate only about 20% of emitted light to the outside, and thus, have relatively low light efficiency. In order to enhance light efficiency and color purity, a micro-cavity structure is used. However, even if the micro-cavity structure is used, a spectrum may change depending on the viewing angle, and luminance may be reduced (e.g., significantly reduced) as the distance from the front of the screen of the OLED increases."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "One or more example embodiments provide organic light emitting devices (OLEDS) having resonant structures with wider viewing angles.

"According to at least one example embodiment, an organic light emitting device (OLED) includes: a first electrode on a substrate; an organic light emitting layer on the first electrode; a second electrode on the organic light emitting layer; and an optical path difference compensation layer including at least two layers, the optical path difference compensation layer being between the substrate and the first electrode or on the second electrode, and the optical path difference compensation layer including at least one layer in which a transmittance decreases as an angle between incident light and an incident surface of the optical path difference compensation layer increases.

"According to at least some example embodiments, the optical path difference compensation layer may include: a first layer, a dielectric layer, and a second layer. According to at least one other example embodiment, the optical path difference compensation layer may include: a first dielectric layer, a first layer, a second dielectric layer, and a second layer. The first layer and the second layer may be formed of the same or different metals. The first layer and the second layer may have thicknesses between about 5 and about 30 nm. The first layer and the second layer may be formed of at least one of Ag, Au, Al, and an alloy thereof.

"According to at least some example embodiments, the first dielectric layer and the second dielectric layer may have different refractive indices. The optical path difference compensation layer may have a thickness greater than 0 and less than about 300 nm. The optical path difference compensation layer may include a first metal layer and a second metal layer having different refractive indices. The optical path difference compensation layer may be formed of a semi-transmissive layer.

"According to at least some example embodiments, the organic light emitting layer may include an electron transport layer, a light emitting layer, and a hole transport layer. The organic light emitting layer may further include an electron injecting layer and a hole injecting layer.

"The optical path difference compensation layer may compensate a resonant optical path difference according to an incident angle of incident light.

"One of the first electrode and the second electrode may be a transparent electrode, and the other may be a reflective electrode.

"The first electrode and the optical path difference compensation layer may form a micro-cavity, or the second electrode and the optical path difference compensation layer may form a micro-cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

"Example embodiments will become more apparent by describing in detail the attached drawings in which:

"FIG. 1 is a cross-sectional view schematically illustrating an organic light emitting device (OLED) according an example embodiment;

"FIG. 2 is a cross-sectional view illustrating an example of an organic light emitting layer according to an example embodiment;

"FIG. 3 is a cross-sectional view illustrating example operation according to an incident angle of light in an optical path difference compensation layer according to an example embodiment;

"FIG. 4 is a cross-sectional view illustrating an example of an optical path difference compensation layer according to an example embodiment;

"FIG. 5 is a cross-sectional view illustrating another example of an optical path difference compensation layer according to an example embodiment;

"FIG. 6 is a cross-sectional view illustrating another example of an optical path difference compensation layer according to an example embodiment;

"FIG. 7 is a diagram illustrating an operation of an optical path difference compensation layer according to an example embodiment;

"FIG. 8 is a cross-sectional view schematically illustrating an OLED according to another example embodiment;

"FIG. 9A is a pictorial view illustrating an example spectrum according to a viewing angle in a comparative example; and

"FIG. 9B is a pictorial view illustrating an example spectrum according to a viewing angle of an OLED according to an example embodiment."

For more information, see this patent application: LEE, Gae-hwang; SHIM, Hong-shik. Organic Light Emitting Devices. Filed October 24, 2013 and posted May 22, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5625&p=113&f=G&l=50&d=PG01&S1=20140515.PD.&OS=PD/20140515&RS=PD/20140515

Keywords for this news article include: Samsung Corning Precision Materials Co. Ltd.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Politics & Government Week