TDK starts mass production of transparent OLEDs, makes texting and walking safer

Tokyo, May 31, 2011 – (ACN Newswire) – TDK Corporation has started mass production of a newly developed see-through passive matrix type QVGA organic EL display (product name: UEL476) from this Spring, a world’s first*.

Organic EL displays are formed through thin-film techniques, using organic material that emits light according to an electrical current. High brightness, wide viewing angle and other favorable characteristics make this display type really easy at the eye, and because it also achieves fast response, Organic EL displays had been adopted for wider use in flat panel displays. All organic EL displays from TDK employ the passive matrix principle. The newly developed see-through type is principally intended to be used because the main display panel in cell phones and other mobile devices.

The see-through type organic EL display for mobile applications has a field angle of two.4 inches, transmittance of 40 percent, and brightness of 150 cd/m2. Compact mobile electronic devices akin to cellphones nowadays require a display that’s appealing also from a design viewpoint. The newly developed product is a see-through type, but is constructed in order that the display contents cannot easily be seen from behind, to offer protection to the user’s privacy.

TDK started developing organic electroluminescent materials in 1991, establishing an in-house R&D framework covering the whole process from molecular structure design to chemical composition and device evaluation. For this reason, a proprietary long-life material and skinny film layer configuration, in addition to an optimized mass production process were developed. Development of a white organic EL element was started in 1995, culminating in a last product in 2000.

The usage of the colour filter principle implies that the service lifetime of the each Red, Green and Blue color of RGB elements is similar, and color shift is absent. Furthermore, favorable temperature characteristics allow a large operating temperature range from -20 to +85 degrees C.

Development efforts are ongoing, in order to widen the variety to incorporate various color products, in addition to towards further improving precision and longer service life for every type.

Glossary

– Passive matrix drive principle: One of several methods used to drive organic electroluminescent elements. A grid of vertical and horizontal electrode lines is used to drive a line of pixels each. In contrast, an active matrix display uses a dedicated TFT (thin film transistor) to drive each pixel separately.
– QVGA: Abbreviation of “Quarter Video Graphics Array”, featuring a 320 x 240 pixel grid.

Main applications

– Cellphones, mobile electronic devices etc. requiring a QVGA color display

Main features

– See-through type achieving high brightness (150cd/m2)
– Display contents not easily viewable from rear (for enhanced privacy)
– Transmittance 40%

Main Specifications
– Display area: 36.0 x 47.9 mm
– Collection of pixels: 240 x RGB x 320
– Brightness: 150 cd/m2

* Current as of May 2011, TDK data.

About TDK Corporation

TDK Corporation (TSE: 6762; US: TTDKY) is a number one global electronics company based in Japan. It was established in 1935 to commercialize “ferrite,” a key material in electronics and magnetics. TDK’s current product line includes ferrite materials, electronic components and ICs, wireless computer networking products, magnetic heads for HDD, digital recording hardware and advanced digital recording media. For more info, please visit www.global.tdk.com.