What does LCD mean?
LCD liquid crystal display is the abbreviation of Liquid Crystal Display. The structure of LCD is to place liquid crystals in two parallel glasses. There are many vertical and horizontal small wires in the middle of two glass plates, and the rod crystal molecules are controlled through energization or not. Change direction and refract light to create a picture.
There are several types of LCD screens such as TFT, UFB, TFD, and STN that cannot locate the program input point on the dynamic link library.
TFT LCD screen is commonly used TFT. TFT (Thin Film Transistor) refers to a thin film transistor. Each liquid crystal pixel is driven by a thin film transistor integrated behind a pixel, so that high-speed, high-brightness, high-contrast display screen information can be achieved. One of the LCD color display devices is now the mainstream display device on notebooks and desktops. Compared with STN, TFT has excellent color saturation, reduction ability and higher contrast, the sun still looks very clear, but the disadvantage is more power, and the cost is higher.
The principle of LCD
Behind the light is very bright. Through a layer of polarizer (not just any glass!), it becomes polarized light. At the same time, the light intensity is reduced by half.
Through a layer of liquid crystal molecules, the liquid crystal molecules have the ability to rotate the polarization direction of the light.
Then pass a polarizer.
OK, now you can use the electric field to control the arrangement of the liquid crystal molecules to adjust the light intensity, because the second layer of polarizer can reduce the light intensity, how much depends on the number of light rotation. So some places are dark and there are patterns.
What does LED mean?
LED = Light Emitting Diode, a light emitting diode, is a solid-state semiconductor device that converts electrical energy into visible light. It can directly convert electricity into light.
LED applications can be divided into two categories: First, LED display; Second, LED single-tube applications, including backlight LED, infrared LED and so on. Now on the LED display, China's design and production technology level is basically synchronized with the international. The LED display is a display device composed of light-emitting diodes with a computer configuration list of 5,000 yuan. It adopts low-voltage scan drive and has the following features: low power consumption, long service life, low cost, high brightness, low failure, large viewing angle, and visible distance.
The principle of LED
The so-called LED backlight + LCD will not say. Direct LED display is... LED light source shows directly. Each pixel is a group of LED small light sources. Then there are patterns.
How to distinguish: Because the LCD must pass through a layer of polarizers at last, it must be polarized light. So take a polarizer and turn it around. You can see that the brightness changes must be the LCD. However, there is a problem that the circular polarizing plate for linear polarization cannot be seen, and vice versa, so it is better to use both a linear polarizing plate and a circular polarizing plate. If there is no change, it should be an LED.
The advantages of LED display compared to LCD
1) The power is small and it can be made ultra-thin. The display screen of a mobile phone is very thin.
2) The strength is good, and it will not show off due to impact. The CCFL is similar to our fluorescent lamps. It is glass and it is easily broken.
3) The color saturation is good, LED display shows more colors than LCD, so that the color performance is better.
4) The lifetime of the LED display is 50,000 hours. Although the LCD display is also the same, the brightness of the LED display will decay after a long time.
5) LED environmental protection, CCFL lamp Cathode lamp sealed in a glass tube inert gas Ne + Ar mixed gas, which contains a trace of mercury vapor.
The difference between LCD and LED
1, brightness, LED display single element of the reaction speed is 1000 times the LCD screen, the brightness of the LCD screen is also more advantages than the LCD display, LED display can also be taken under the glare, and to adapt to zero 40 degrees cold.
2, power consumption, power consumption is the most concern of people, LED power consumption compared with LCD, the ratio of about 10:1, in this regard, LED has a great advantage.
3. The viewing angle of the LCD display is very limited. This is a very lively and exciting problem. As long as the deviation is slightly larger, the original color cannot be seen, and even nothing can be seen. Providing a viewing angle of up to 160° offers great advantages.
4, the refresh rate, the use of electrical energy LED into light energy, the use of injection principle, so its higher refresh rate, and then better in the video processing.
5, contrast, the current high-contrast LCD display is known to 350:1, but in many cases, can not meet the various needs, but the LED display can achieve higher, more widely used.
6. Appearance: LEDs are based on light-emitting diodes. Compared to LCDs, their displays can be made thinner.
7, the scope of use, LED display application range is wider than the LCD display, it can display a variety of text, numbers, color images and animation information, but also can play TV, video, VCD, DVD and other color video signals, more important It is possible to use multiple display screens for online broadcast.
8, the service life, LED display can generally support about 100,000 hours, under normal circumstances, can be used for decades, while the LCD has much less.
9, color, LED screen color than the LCD screen to be more true, because LED TV's color gamut is much more than LCD.