What are the connections and advantages of AMOLED, PMOLED and OLED? As screens become more and more important to electronic products, companies have gradually increased their investment in display screens. Currently, the three most promising screen technologies are PMOLED, OLED, and AMOLED. Take mobile phones as an example. The current mainstream display devices of mobile phones are LCD panels. However, the new technology of AMOLED has been used in many high-end mobile phones. Many industry insiders believe that it will become the mainstream of mobile phone screens in the next few years. What are the characteristics of OLED, the connection and difference between PMOLED and AMOLED, and what are their advantages? This article will elaborate one by one.
Two major technical branches of OLED: PMOLED and AMOLED
The characteristics of OLED display are self-luminous, high contrast, low power consumption, light weight, thin thickness, etc. It is called the next generation display technology. According to the driving method, OLED can be divided into active driving (AMOLED) and passive driving (PMOLED) Two kinds.
Each pixel of AMOLED is equipped with a TFT (Thin Film Transistor) with a switch, and its driving method is easier to achieve high brightness, high resolution, high color performance, and low energy consumption. This type of panel is widely used in consumer electronics; PMOLED has a simple structure, The manufacturing process is easy, the manufacturing cost can be effectively reduced, and the response speed is extremely fast. It has great potential for the development of simple display micro-devices. PMOLED will have the problems of large power consumption and reduced lifespan, and the product size is limited to about 5 inches.
The connection, difference, advantages and disadvantages of PMOLED and AMOLED
Both PMOLED and AMLED belong to OLED. The difference is the driving method. PMOLED is also called passive matrix organic electroluminescent diode. PMOLED and STN LCD have similar light-emitting principles. AMOLED is also called active organic electroluminescent diode. AMOLED is also called active organic electroluminescent diode. Just like TFT LCD.
PMOLED simply forms a matrix with cathodes and anodes, and illuminates the pixels in the array in a scanning manner. Each pixel is operated in short pulse mode to emit light with instant high brightness. It has the advantage of simple structure and can effectively reduce manufacturing costs. However, the high driving voltage makes PMOLED unsuitable for large-size and high-resolution panels, which is different from the current development.
AMOLED uses independent thin film transistors to control each pixel. Each pixel can be driven to emit light continuously and independently. It can be driven by low-temperature polysilicon or oxide TFT. The advantages are low driving voltage and long life of light-emitting elements. However, the high cost and manufacturing process are more complicated, and the cost is more difficult to control.
PMOLED is not suitable for displaying dynamic images because the response speed is relatively slow, but it is very energy-efficient; AMOLED is characterized by fast response speed and can be used for large-size TV panels. The disadvantage is that it consumes a lot of power.
The connection and difference between AMOLED and OLED
Although LEDs are also common in daily life, in the screen, the size of each LED is very small, and is divided into three sub-pixel groups of red, green and blue, and then form different colors, and the arrangement of sub-pixels The way will also affect the entire display effect. The O in AMOLED stands for Organic, which is "organic". Simply put, a series of organic thin film materials are used between the positive and negative electrodes to achieve the purpose of light emission. AM stands for Active Matrix, which is relative to Passive Matrix and refers to the driving method of each OLED pixel.
In Passive Matrix, the control of each pixel is realized through a complex electrode network, so as to realize the charging and discharging of a certain pixel. Generally speaking, the control method of Passive Matrix is relatively slow and the control accuracy is slightly lower. Unlike Passive Matrix, Active Matrix is equipped with TFT and capacitive layer on each LED, so that when a certain row and a certain column are energized to activate the intersecting pixel, the capacitive layer in the pixel can be refreshed between two refreshes. Maintain the charged state, so as to achieve faster and more accurate pixel light-emitting control.
OLED is also known as organic electro-laser display and organic light-emitting semiconductor. It is a different type of light-emitting principle from liquid crystal display. The main advantage of OLED screen is the high controllability of the pixels. Each pixel can be independently switched to achieve more purity. Black and higher contrast. In addition, turning off unnecessary pixels when displaying images can also reduce power consumption; because the internal layers of the screen module are less, the light transmittance is also better, which is conducive to achieving higher brightness and wider viewing angles.
OLED screens can be made very thin, which is very suitable for mobile devices such as mobile phones. Due to the lack of a hard backlight layer and the maturity of flexible plastic substrates, OLEDs also have great advantages on flexible screens, which will give future mobile devices even It is wearable devices that create more possibilities in form.
AMOLED belongs to OLED, but the reverse is not true. Simply put, OLED technology includes PMOLED and AMOLED. PMOLED does not require a TFT backplane, but the size cannot be made large; AMOLED can be made large in size. PMOLED mainly exists in early dual-screen mobile phones, used for small external screens, and current mobile TVs all use AMOLED technology.
AMOLED is an active organic light-emitting diode. It does not only need to add a signal to work, it also needs an additional point source to make the diode reach the working state. At this time, it will light up or not light up the signal. closure. To use an inappropriate analogy, it works like a TV. You connect a cable signal to it, but you can't see it. You can only watch it when you power it up. But only electricity, no cable signal, and no programs to watch.
From the structural point of view, OLED is basically a two-stage tube, and AMOLED is a three-stage tube or a plurality of transistors jointly driving a light-emitting point.
The connection and difference between PMOLED and OLED
PMOLED stands for passive matrix OLED, which is related to the way of controlling (or driving) the display. PMOLED display is a simple control scheme in which you control each row in the display in turn. PMOLED electronics do not contain storage capacitors, so the pixels in each row are turned off in most cases. To compensate for this, you need to use more voltage to make them brighter.
The advantage of PMOLED is that the process is simpler and the structure is simple. The disadvantage is that it is difficult to increase the size of the panel. In order to maintain the brightness of the entire panel, it is necessary to increase the brightness of each pixel and increase the operating current, which will reduce the life of the OLED device and make current drive control difficult.
Problems faced by AMOLED on the road to popularization
Compared with PMOLED, because AMOLED has more obvious advantages, it is more practical and popularized faster, and has developed into the mainstream OLED technology, which inherits the energy-saving, ultra-thin and flexible characteristics of OLED material, but it is currently developing and Immature.
The problems in the industrialization of AMOLED include three major aspects. The longevity of blue OLED luminescent materials has not been resolved, which affects the overall life of the display screen. There are also many problems with the screen color. The cost disadvantage is also the current difficulty. .
The reasons why AMOLED is complained by users include that the color reproduction is not as good as that of IPS screens, the graphics on the screen are dense and gorgeous, too full, and the colors are thoroughly vulgar, etc. However, people are still optimistic about this technology.
Both OLED and AMOLED are known as the next-generation display technologies that are most easily popularized. Samsung Electronics, Samsung SDI, LG, and Philips all attach great importance to this new display technology. Domestic companies such as Tianma Microelectronics, BOE, Visionox, and Huaxing Optoelectronics, Hongshi, etc. are also actively deploying, and the prospects are very broad. With the addition of domestic enterprises, China's "lack of cores and fewer screens" may change.
