New breakthrough of OLED display technology

New OLED technology has not stopped, in 2006, the overall matrix (Total Matrix Addressing, TMA address) OLED technology by Cambridge Display Technology launched, allegedly with small passive array TMA solution displays, can reduce the power consumption of at least 50%, or under the same power consumption, get two times the brightness of the display.

Prior to the publication of the TMA technology, a large OLED display can only be achieved using an active matrix (AM) technique combined with an expensive thin-film transistor (TFT). Passive matrix (PM) displays are driven by cheaper external chips, but have been limited to smaller screen sizes.

TMA is a technology that can be used to drive the active matrix function to the passive matrix display. TMA reduces the power consumption of a given prime number in a passive matrix display and increases the lifetime of the panel.

Through TMA technology, manufacturers offer a competitive alternative to the passive matrix display technology to expand the capacity of active matrix in the field of practice is to reduce the power consumption or the same power, to increase the brightness or improve the resolution. In addition, TMA can also use the passive matrix driver addressing function to expand the scope of the panel size. TMA drive system for polymer and small molecule OLED two displays.

The same year, OLED color electronic paper "new breakthrough -- LG.Philips LCD with amorphous silicon (a-Si) technology successfully developed the world's first full color, deformation, active matrix (AM), organic electroluminescent diode (OLED) display device.

This new OLED electronic paper "4 inches long, the resolution is 320 * 240QVGA, can display 16770000 colors, hair and the thickness of 150 m, not much difference between, and then a layer of stainless metal substrate, to ensure its availability and heat resistance, combined with the a-Si new production process, the overall stability is improved.

LG.Philips LCD is working with the United States universal display technology company (UDC) to develop this new type of display device, while the latter holds the original OLED phosphor technology patents.

In May 2006, LG.Philips LCD developed the first 14.1 inches (A4 size) color electronic paper display device, and introduced its color version. Full color deformable AM OLED display device.

2007, display technology and new breakthroughs: Sony Corp developed its claim to be the industry's first use of full color active matrix organic LED display folding plastic bottom, and in the international society for information display conference shows the product prototype. In the course of the development of the laboratory, SONY engineers first developed a glass substrate on the construction of organic thin film transistor backplane process, and in reality the same structure will be copied to the plastic film. The temperature of the process is less than 180 DEG C. SONY uses C22H14 and five benzene material to build for the activity of organic transistors 0.1cm2/Vs.

The product prototype is a 2.5 inch display with a 120 x 160 pixel and a 8 bit gray level, in order to achieve full color effect of 16 million 800 thousand colors. The display resolution of 80 pixels / inch (per pixel size of 318 m * 318 m), each of the sub pixels (red, green or blue) are composed of a double transistor one capacitor PMOS voltage programming circuit to drive the frame rate of 60Hz, 12V, signal voltage.

SONY uses a top emitting structure on the OLED display, which is about to drive the transistor at the bottom, emitting from the top OLED layer. The display comprises an electrode layer, an organic TFT layer, a OLED layer and a cathode layer. It is said that this structure allows engineers to make an electrode layer before making an organic TFT layer without damaging the semiconductor layer.

Flexible OLED display technology

Flexible OLED display is one of the most popular research topics in the field of display technology. OLED has more advantages than other flexible displays: it is self luminous display, fast response, wide viewing angle, the preparation of organic materials, such as strong bending capacity. Therefore, it has a very wide range of applications, such as portable products and military applications.

The main problems that need to be solved in the flexible display are the adhesion performance of the electrode layer and the organic layer, the tightness of the substrate, the packaging and driving technology. At present, there are CDT, UDC, Samsung, Pioneer, SONY and China's Tsinghua University developed polymer and small molecule OLED soft screen samples, application of active driving technology and thin film packaging technology has greatly enriched the flexible display color and prolong the life of OLED. In the 2007SID exhibition, SONY company launched its first TFT drive 2.5 inch flexible OLED sample, achieved about 16 million 700 thousand full-color color display, the pixel size is 318 m square, the fine degree of 80ppi, to achieve the highest degree of fine.

Because OLED is very sensitive to water and oxygen, how to avoid the influence of these two kinds of atmosphere on the device is the most important factor in the development of flexible OLED. Research shows that the water vapor permeability OLED below 10 ~ 5g/m2/day, but the traditional metal or glass packaging not suitable for flexible package, how to avoid the influence of water and oxygen on the device is a main subject of flexible OLED development. Vitex company uses polymer inorganic materials alternating composite film (PML) to block water oxygen, its development of soft screen substrate products with glass comparable barrier effect. Japan's Pioneer Co calculations, the use of this technology packaged devices, the initial brightness of the 1000cd/m2, the maximum life of more than 5000 hours. However, due to the current OLED soft screen packaging technology is far from mature, so flexible OLED display technology is still in the stage of basic research.