TFT Display Module.How should I choose? With the rapid development of flat panel display technology, in the face of endless LCD, LED, OLED, AMOLED and other terms, how should we choose, home flat screen TV, mobile phone screen which is better?
1. What is LCD?
LCD (Liquid Crystal Display) is a liquid crystal display (LCD). Its construction principle is that two glass substrates are stacked, the middle is filled with TFT (thin film transistor), and the upper substrate is added with a color filter; loading TFT voltage changes the direction and rotation of liquid crystal molecules, controls the polarized light of each pixel, and finally displays the picture.
Because the LCD itself cannot emit light, and under normal light conditions, the picture cannot be seen at all, so backlight is needed to illuminate every pixel of the screen body. Just like the advertising light box we see at night, the interior needs to be illuminated. The early liquid crystal display screen mainly adopts CCFL (cold cathode fluorescent lamp) technology, which uses the cold cathode gas discharge to excite the phosphor and emit light.
CCFL has the advantages of high brightness and high color reduction at that time, but its module has the advantages of large size, high energy consumption and high calorific value, which is obviously incompatible with our modern environmental protection concept of low energy consumption, and it is difficult to lighten products, so LED backlight technology was born.
2. What is LED?
LED light emitting diodes are electronic components that efficiently convert electrical energy into light energy. In the field of liquid crystal, light emitting diode is used as a backlight display technology, so in the field of liquid crystal display, the exact name of LED should be “LED backlight technology liquid crystal display”.
LED module has small size and high energy efficiency. Now LED backlight is widely used in low-end liquid crystal display technology, which basically completely replaces CCFL, but the color reduction of LED backlight is not as good as CCFL. There are still some products using CCFL backlight technology in the field of professional design and drawing.
2.2 Mini LED.
MiniLED is a LCD screen backlight technology, in essence there is no difference with LED, this technology is also easy to understand, in the past, the screen backlight is a whole piece, to be bright on, off on all, while the MiniLED screen backlight is composed of a lot of lamp beads, the need for bright parts on, do not need bright parts on off. To put it simply, it is the LED backlight technology in which the individual size becomes smaller, the total number increases greatly, and the switch can be controlled independently.
The advantage of this is that the light and shade of the screen can be more accurately controlled. There is an independent drive circuit on each side of the Mini LED, so the dimming response speed is faster, the control precision is higher, the backlight response speed and accurate brightness of each partition can be greatly improved, and the thickness of the backlight module can be reduced.
In short, Mini LED is a technology to improve the contrast of liquid crystal displays.
QLED (Quantum Dot Light Emitting Diodes, quantum dot light emitting diode) is a trademark created by Samsung and is essentially a backlight technology that uses quantum dot technology to improve the quality of LCD TVs. As a result, the TV has a wider color gamut and brightness, the reason is that quantum dots are like filters, the light produced is purer than ordinary LED.
In addition, there are DLED (direct backlight), ELED (side-in backlight) and so on, which is essentially a kind of LED backlight technology. The screen display mode is still liquid crystal panel, and the space is limited, so it is no longer described one by one.
2.4Electronic display screen of LED.
In the field of large area display, LED is another display technology-LED electronic display screen. The principle is that by controlling the brightness of light-emitting diodes, each pixel consists of three light-emitting diodes of red, green and blue, and controls the intensity of red, green and blue light of three diodes, so that pixels have different colors, and each diode has 0-255 levels of brightness (grayscale). Theoretically, each pixel has countless colors (3 to the power of 255). The distance between pixels is the most important index to judge the LED electronic display screen. For example, the number after the P1.25gradeP2.5gradeP5PowerP10PowerP is the pixel spacing, the smaller the number, the smaller the pixel spacing, the higher the definition of the picture, and of course the higher the price. Multiple pixels form a LED module, and the whole display screen is composed of many modules. For example, in the following parameters, the module size is 200mm × 150mm, and the module resolution is 160dots × 120dots, which means that each module is 200mm × 150mm, with 19200 pixels.
LED electronic display screen has three kinds of single color, two color and full color. As the name implies, there is only one kind of lamp color, two colors have two colors, and three colors are full color, which correspond to different application scenarios. Because the display screen is spliced by LED module, it can theoretically do infinite display. Daily outdoor advertising display screen and various variety party background display screen are all LED electronic display screen.
2.5 Micro LED.
Further reduce the pixels of the LED electronic display screen, and you get Micro LED. The pixel spacing is even smaller, and the chip size is reduced to less than 50 μ m. The display technology is basically the same as the ordinary LED tricolor display. The scope of application extends from flat panel display to AR/VR/MR, spatial display, flexible transparent display, wearable / implantable optoelectronic devices, optical communication / optical interconnection, medical detection, intelligent lights and many other fields.
3. What is OLED?
OLED is the abbreviation of (Organic Light-Emitting Diode), which translates into “organic light-emitting diode”. Its principle is the phenomenon of luminescence by carrier injection and recombination, and the luminous intensity is proportional to the injected current. Under the action of electric field, the holes produced by the anode and the electrons produced by the cathode will move into the hole transport layer and the electron transport layer, respectively, and migrate to the light-emitting layer. When the two meet in the luminous layer, they produce energy excitons, which excite the luminescent molecules.