he display is called one of the greatest inventions of the twentieth century, and our lives shine. Along with the development of science and technology, the display is not limited to the application of TV screen, large size of commercial display began to break into our life, shopping malls, cinemas, indoor sports venues and other places can see its figure, while the LCD, LED, OLED and other professional terms also linger in our ears, although there are a lot of people talk about them, but most people know little about them, "long" and their similar is the difference?
Let Zhu Jinger (jack zhu), director of Grace Lighting Technology, explain your question:
LCD display screen
First, here there is a design map of LCD and OLED, which is a longitudinal section of each sub-pixel
The difference between LCD and OLED
The luminous principle of LCD mainly depends on the backlight layer, Of the Back-light section in the image above, This section usually consists of a large number of LED backlights, It has only one function, Is showing the white light, But white light can't make up an image, So we added a colored film to the white backlight layer, The white backlight penetrates the colored film and shows color, But we need to adjust the ratio of red, green and blue ah, You can't let the light go through red, green and blue, So we added a control valve between the backlight layer and the color film, This is the layer of the liquid crystal in the picture, What we call the liquid crystal layer, This layer can control the degree of opening and closing by changing the magnitude of the voltage, So there is more light from the open and closed ones, The small ones emit less light, So that we can control the amount of white light, So you can adjust the ratio of red, green and blue. This is how the LCD screen works, what it looks like, you hold a white flashlight, an opaque board in the front, and a colored plastic film in the front.
Take the Grace Light-WIFI Radio pool LED Pa lamp (GL-Smart4S) as an example, it uses the most well-known TFT-LCD as a thin-film transistor LCD display.
Its basic structure is placed in two pieces of parallel glass substrate liquid crystal box, under the substrate glass set film transistor (i. e. TFT), on the substrate glass set the color filter, through the signal on the film transistor and voltage change to control the direction of liquid crystal molecules, so as to control each pixel polarization light emission or not and achieve the purpose of display it.
Advantages and disadvantages of LCD
The LCD is definitely better than the OLED at the same resolution (unadjusted), and then the LCD is thicker because it can't glow, so he wants a backlight and then the top piece of glass. It's like a projector, a light source, a photo, a screen. The advantage is not to flash the screen, will not burn the screen, the cost is low, see for a long time the eyes will not be tired, not easy to break. The disadvantage is that the display effect is not so good, there is a drag shadow, relatively heavy, can not use the fingerprint under the screen, the special-shaped screen is more difficult to do
LCD currently has a fatal problem, that is the liquid crystal layer can't completely off, so if the LCD display black, there will be part of the light through the color layer, so the LCD black is actually a white and black mixed gray, like you take a white flashlight shoot a black film, through the film of light will become black light? Definitely not, what you look at on the film side is actually a dramatically decreasing gray in brightness, not pure black. OLED is different. When OLED shows black, it can directly close the pixels in the black area to achieve almost pure black effect. In addition, due to the existence of backlight layer, so the backlight of LCD display is very easy to leak from the gap between the screen and the frame, this is often said that the display light leakage, LCD can not completely avoid light leakage phenomenon, can only be serious.
OLED self-emitting display screen
Take the Grace Light-retro background light as an example: an OLED display made of organic electroluminescent diodes. The OLED consists of an external OLED display unit and a luminous material sandwiched therein, including a cathode, emission layer, conductive layer, anode, and substrate. Each display unit of the OLED produces three different light colors, Due to the same time with self-illumination and electromechanical excitation light diode, no backlight, high contrast, thin thickness, wide viewing Angle, fast reaction speed, can be used for flexible panel, wide temperature range, simple structure and manufacturing process and other excellent characteristics, is considered as the next generation of flat surface display emerging application technology. OLED does not need the backlight layer like LCD screen, nor does it need to control the amount of light, as long as it is powered to light on, so OLED is like a screen with countless small color bulbs. A prominent example of OLED use today is the mobile phone screen. The OLED screen can display the perfect picture contrast, and the display screen will be more vivid and real. The LCD screens can not be curved due to the characteristics of the LCD, and the OLED can be made into a curved screen.
Advantages and disadvantages of OLED displays
It is self-luminous only need a power can be displayed, first of all, it is relatively light, touch rate is higher than LCD, there will be no shadow, you can use the screen fingerprint, low power consumption, rich color display. LCD has a much thicker thickness than LCD due to the backlight layer and LCD layer, so the OLED screen is very easy to thin the phone or display, and the thinner screen allows you to add more components to improve other parts of the experience.
The disadvantage is that the eyes are very tired after looking for a long time, and the screen flash will be very serious, which can be adjusted through the DC dimming (change the circuit), without shadow, and it is easy to burn the screen after using for a long time
LED digital display screen
Take Grace light-12 waterproof wireless control battery power LED pa lights as an example: LED display (LED display) is a flat panel display, composed of a small LED module panel, used to display text, image, video, video signal and other information equipment. The LED is short for Light Emitting Diode, or a light-emitting diode. It is a type of semiconductor diode that converts electricity into light energy. Electrons can radiate visible light when recombined with holes, so they can be used to make light-emitting diodes. The light-emitting diode is composed of a PN junction like the ordinary diode, which also has unidirectional conductivity.
When the forward voltage is added to the light-emitting diode, the hole injected into the N zone from the N zone and the electrons injected into the N zone are combined with the electrons in the N zone and the hole in the P zone in the PN junction, producing the fluorescence of spontaneous radiation. Electrons and holes are located in different energy states in different semiconductor materials. When electrons and holes are combined, the energy released is somewhat different, and the more energy released, the shorter the wavelength of the light emitted. Often used are diodes with glowing red, green, or yellow light.
Advantages: although the LED display is also composed of unit panels, but because its lamp beads are encapsulated on the unit board, so in the splicing can be seamless splicing, good flatness, no like the influence of LCD frame, so its brightness is very high, and support adjustment, waterproof, sunscreen, moisture advantage, so it can be installed in the outdoor, the environment is stronger; there are many specifications, users can choose the corresponding specifications according to their own application;
Disadvantages: the definition is general, the color contrast of the ED display is general, so when displaying the gorgeous image, the effect it shows is not very bright, especially when reducing its brightness, the whole screen will be gray, not like the LCD screen. The lamp beads of LED display screen often drop during transportation, installation and use, resulting in the situation of individual pixels that are not bright, so it will affect the overall image display effect
The difference between the three people
1. On the color gamut
OLED LCD screen can display endless colors, and is not affected by the backlight, pixels are very advantageous when displaying all black pictures, the LCD LCD color gamut is currently between 72 percent and 92 percent, while the LED LCD screen color gamut is more than 118 percent.
2. On price
LED LCD screen of the same size is more than twice as expensive as LCD LCD screen, while OLE LCD screen is more expensive.
3. In terms of technology maturity
Because LCD LCD screen is a traditional display, it is much better than OLED LCD screen and LED LCD screen in terms of mature technology, such as display reaction speed, OLED LCD screen and LED LCD screen is far less than LCD LCD screen.
4, in the Angle of the display
OLED LCD screen is much better than LED LCD screen and LCD LCD screen, specifically, the visual Angle of LCD screen is very small, while LED LCD screen is unsatisfactory in the sense of hierarchy and dynamic performance, in addition, the depth of LED LCD screen is not good enough.
Therefore, whether OLED, LCD or LED are not perfect, and which technology is better? It depends on personal interests, since all three have their advantages and disadvantages. Foshan Grace Lighting Equipment Co., Ltd. is also trying to improve the technology, adjust and improve the various restrictions of LCD, improve the OLED brightness and trying to reduce its cost price, I believe it will not be long, with a better display will be available, look forward to it!