LCD (liquid crystal display) uses the latest full-color display technology, and the principle is simple and easy to understand. Basically, the whole concept of liquid crystal display technology is to use the physical characteristics of liquid crystal: when the power is on, it turns on, and the arrangement becomes orderly, so that light can easily pass through; When there is no electricity, the arrangement is disordered to prevent light from passing through. Let the liquid crystal block like a gate or let light pass through. In terms of technology, the liquid crystal panel contains two rather exquisite sodium free glass materials, called substrates, with a layer of liquid crystal sandwiched between them. When the light beam passes through this layer of liquid crystal, the liquid crystal itself will stand or twist in an irregular shape, so as to block or make the light beam pass smoothly.
Compared with CRT display, LCD overcomes the disadvantages of large volume, power consumption and flicker of CRT, but it also brings some problems, such as high cost, poor viewing angle and unsatisfactory color display. But technically, the advantages of LCD are still very obvious, and the specific performance is as follows:
- Smaller volume and lighter weight
The traditional CRT display uses the picture tube technology to image, so it needs to contain the vacuum picture tube, and then it is equipped with an electron gun at the end, so that its length is generally more than 30 cm, so the volume of the whole display is certainly larger. For example, the LCD uses liquid crystal materials, and then uses the corresponding imaging technology to achieve the purpose of display. There is no need to install a picture tube inside the display, so the volume is small. For example, the 15 inch LCD bm-568 of EMC has only half to one third of the volume of a 19 inch CRT display, and it has great flexibility when placed, Of course, its small volume also greatly reduces its weight.
- Larger relative display area
Due to the limitation of display technology, the size of traditional CRT display is smaller than the display area of fluorescent screen. Generally, although the size of a 15 inch CRT display is 15 inches, its real visual range may only be about 14.1 inches, while the display area of a 17 inch display may only be 15 to 16 inches below. However, due to the different surface image principle of LCD, the size marked is the actual display area. For example, the display area of Samsung’s 15 inch LCD is completely 15 inches, which is equivalent to the display area of a 17 inch CRT display. If the price difference between the two is not much, of course, it is much more cost-effective to buy a LCD.
- Zero radiation, no flicker
CRT display uses cathode picture tube imaging, its contained electron beam will produce a lot of static electricity and radiation when it moves, and the faster the electron beam runs, the greater its radiation. Long term use of human body will cause damage to eyes and skin, resulting in myopia, skin allergy and other problems. The liquid crystal display uses liquid crystal materials, so it does not need to use electron beam, so there is no electrostatic and radiation problems that affect vision. In addition, the formation of a picture of CRT display is formed through horizontal scanning. There is no flicker only when the scanning frequency reaches a certain value. LCD does not need any scanning process. A picture is formed almost at the same time. Even if the refresh frequency is very low, there will be no flicker.
- Low power consumption and strong anti-interference ability
In addition to the circuit and image power consumption, CRT displays also have the power consumption of the display screen, while LCD displays are mainly backlight and circuit power consumption, and the power consumption of the display screen is negligible. For example, the power consumption of EMC’s 15 inch display bm-568 is only 35 watts, which is nearly 50% less than that of CRT products with the same display area. In addition, unlike CRT display, LCD is not imaged with color picture tube and electron gun. It does not need to consider the high radiation impact caused by improving the electron beam emitted by the electron gun, but only obtains the brightness through the backlight emitted by the fluorescent tube. Therefore, it has stronger anti-interference ability, and will receive good display effect even in the environment with concentrated light.
- Higher picture quality
The traditional CRT display adopts the analog display mode, and the signal output of the display card adopts the analog output mode, which may cause the loss of image and the decline of image quality in the transmission process, while the signal transmission of the LCD adopts the digital mode, which is that the display card directly inputs countless word signals, which will not cause the loss of signals, However, at present, most LCD still adopts VGA interface for analog display, and only a few manufacturers such as EMC, Samsung and Acer have set up digital video signal interface.
- The use function is more intelligent
Due to the different materials and technologies used in LCD, some of its parameters are generally fixed, which requires more intelligent performance adjustment of LCD. In this regard, each manufacturer has its own mature technology. Generally speaking, there are two main types. One is similar to EMC auto set automatic adjustment and optimal setting function, as long as one of the parameters is adjusted, Other parameters are automatically adjusted to the corresponding values and are the best values to ensure the best display effect. The other is the single key recovery function, that is, one key is prefabricated, and all parameters can be changed back to the preset settings at the factory with one click.