OLED display technology classification and characteristics
Blaze Display Technology Co., Ltd. | Updated: Nov 27, 2018
Display technology Classification
1. OLED display technology is divided into two types: polymer process and small molecule process according to the process method. As the polymer process (PLED) does not require a thin film process, the equipment investment and production costs are much lower than those of TFT-LCD (similar to CD-R). The spin-coating method is used to coat the mold), which is more conducive to the development of large-size displays. However, since the attenuation constant of each color of PLED is different, it is not only difficult to make the product colorful, but the service life of the product is also affected. Although small molecule organic electroluminescent elements are better than polymer organic electroluminescent elements in terms of colorfulness, the equipment investment and production cost are relatively high (because of the heating evaporation method to evaporate multi-layer organic film materials, in order to avoid inter-material Mutual contamination, so expensive multi-chamber vacuum equipment must be used, and the driving voltage is high and the output rate is low.
Polymer components perform better in terms of thermal stability, so they can be used in higher temperature working environments and can tolerate higher current densities. However, due to the difficulty of independent positioning of the red, basket and green three-pixels, full-color displays have not yet been introduced. .
2. OLED display technology is divided into passive (passive matrix, namely PM-OLED) and active (active matrix, AM-OLED) according to the driving mode. Passive type is suitable for small-size panels, because its instantaneous brightness is proportional to the number of cathode scanning columns, so it needs to operate under high pulse current, which will shorten the life of the pixel. And because of the scanning relationship, the resolution is limited, but low cost and simple manufacturing process are its major advantages.
The active type is just the opposite of the passive type. Although the cost is more expensive and the process is more complicated (still easier than TFT-LCD), each pixel can be driven continuously and independently, and the driving signal can be memorized without operating under high pulse current. , High efficiency, extended lifespan, suitable for large-size, high-resolution, high-information capacity full-color OLED display products.
Advantage
1. Compared with the crystal layer of LED or LCD, the organic plastic layer of OLED is thinner, lighter and more flexible.
2. The light-emitting layer of OLED is relatively light, so its base layer can use flexible materials instead of rigid materials. OLED base layer is made of plastic material, while LED and LCD use glass base layer.
3. OLED is brighter than LED, and the organic layer of OLED is much thinner than the corresponding inorganic crystal layer in LED. Therefore, the conductive layer and emission layer of OLED can adopt a multilayer structure. In addition, LEDs and LCDs require glass as a support, and glass absorbs part of the light. OLED does not need to use glass.
4. OLED does not need to use the backlight system in LCD. When the LCD works, it will selectively block certain backlighting areas to make the image appear, while the OLED emits light by itself. Because OLEDs do not require a backlighting system, their power consumption is less than that of LCDs (most of the power consumed by LCDs is used for backlighting systems). This is especially important for battery-powered devices (such as mobile phones).
5. OLED is easier to manufacture and can be made into larger sizes. OLED is made of plastic, so it can be made into a large-area sheet. It is much more difficult to use so many crystals and pave them flat.
6. The field of view of OLED is very wide, up to about 170 degrees. However, the LCD needs to block light when it is working, so there are natural observation obstacles at certain angles. OLED can emit light by itself, so the field of view is much wider.
Features Voice
The reason why OLED technology can be widely used is that it has the following advantages compared with other technologies:
(1) Low power consumption
Compared with LCD, OLED does not require a backlight, which is a more energy-consuming part of LCD, so OLED is more energy-efficient. For example, the power consumption of a 24in AMOLED module is only 440mw, while a 24in polysilicon LCD module reaches 605mw.
(2) Fast response speed
Compared with other technologies, OLED technology has a fast response speed, and the response time can reach the microsecond level. The higher response speed realizes the moving image better. According to relevant data analysis, its response speed has reached about 1000 times the response speed of liquid crystal displays.
(3) Wide viewing angle
Compared with other displays, because OLED is actively emitting light, the picture will not display distortion in a large viewing angle range. The vertical and horizontal viewing angles exceed 170 degrees.
(4) Able to achieve high resolution display
Most high-resolution OLED displays use active matrix, or AMOLED, whose light-emitting layer can absorb 260,000 true colors with high resolution, and with the development of science and technology, its resolution will be higher in the future The promotion.
(5) Wide temperature characteristics
Compared with LCD, OLED can work in a large temperature range. According to relevant technical analysis, the temperature can be operated normally at -40 degrees Celsius to 80 degrees Celsius. In this way, geographical restrictions can be reduced, and it can be used normally in extremely cold regions.
(6) OLED can realize soft screen
OLEDs can be produced on different flexible substrate materials such as plastics and resins. The organic layer is vapor-deposited or coated on a plastic substrate to realize a soft screen.
(7) The quality of the finished OLED is relatively light
Compared with other products, OLED has a smaller quality and a smaller thickness than LCD. Its seismic coefficient is higher, and it can adapt to harsher environments such as greater acceleration and vibration.