LCD Monitor

LCD Monitor

Liquid crystal is an organic compound with regular molecular arrangement between solid and liquid. Generally, the most commonly used liquid crystal type is nematic liquid crystal. The molecular shape is elongated rod shape, and the length and width are about 1nm~10nm. Under the action of different electric currents and electric fields, the liquid crystal molecules will be regularly rotated 90 degrees to produce a difference in light transmittance, so that the difference between light and dark when the power is turned on/off, according to this principle to control each pixel to form the desired image .

The difference in resolution between LCD and ordinary CRT monitors

The liquid crystal display is a digital display method. Its display principle is to directly sample and process the analog signal output by the graphics card into a display signal with specific address information (if it is an analog interface), and the color and brightness information of any pixel is on the screen. The pixel points directly correspond to this display principle, so the LCD cannot support multiple display modes like CRT displays. The LCD can only reach the maximum when it displays the same resolution as the LCD panel. Good results. When displaying images with a resolution smaller than the optimal resolution, the LCD uses two ways to display, one is centered display, for example, when a 1024*768 LCD displays a resolution of 800*600, the display will Only the 800*600 pixels in the middle are used to display the picture, and the surroundings are black. In this way, the signal resolution is one-to-one correspondence, so the picture is clear. The only regret is that the picture is too small. The other is the enlargement method. It is to display the 800*600 screen by calculating the resolution to 1024*768. Because the signal processed in this way does not correspond to the pixel one-to-one, although the screen is large, it is relatively fuzzy

How to evaluate the quality of LCD monitors

Viewing angle: The viewing angle of the liquid crystal display includes two indicators: the horizontal viewing angle and the vertical viewing angle. The horizontal viewing angle is expressed by the vertical normal line of the display (that is, the vertical imaginary line in the middle of the display). The displayed image can still be seen normally at a certain angle to the left or right of the normal. This angle range is the horizontal viewing angle of the liquid crystal display. Similarly, if the horizontal normal is the standard, the vertical viewing angle is called Vertical viewing angle. Generally speaking, the viewing angle is based on the contrast change as a reference standard. When the viewing angle is increased, the contrast of the displayed image seen at that position will decrease, and when the angle is increased to a certain extent, and the contrast decreases to 10:1, this angle is the maximum viewing angle of the liquid crystal display.

Response time: When the liquid crystal display is working, when the current passes through the liquid crystal molecules, the liquid crystal molecules will be arranged in the direction of the current, and the liquid crystal molecules will return to the parallel arrangement state when the current is disconnected. This is basically the working state of the liquid crystal panel— —Display the information from the graphics card with the on and off of the current. When the liquid crystal display is working, it takes a certain amount of time for the molecules to be arranged along the current to return to the original state, which will cause a certain stagnation, and this time is the response time we often mention. Because the current is on or off, it is divided into rise time and fall time. The response time we call is the sum of the two. The usual unit of response time is milliseconds (ms).