Detailed analysis of the LCD screen indicators
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Update time : 2017-07-12 15:44:01
Resolution is a very important performance index. It refers to the number of points that can be displayed on the screen in both horizontal and vertical directions. The number of lines and faces on the screen is made up of dots. The higher the resolution, the more information can be accommodated in the same screen. For a 1280x1024 capable of supporting the resolution of the CRT, whether it is 320x240 or 1280x1024 resolution, can be more perfect performance (because the beam can be adjusted flexibly). But the maximum resolution it is not necessarily the most appropriate resolution, because if the 17 inch display to 1280x1024 resolution, WINDOWS font will be very small, a long time eye fatigue, so that the best resolution 17 inch display should be 1024x768.
But not for LCD. The maximum resolution of LCD is its true resolution, which is the best resolution. Once the set resolution is less than the true resolution (such as 15 inch LCD, its true resolution is 1024x768, and the WINDOWS set the resolution of 800x600), there will be a display of the two. First, the central display, only LCD in the middle of the 800x600 points will show the image, the other did not use the point will not shine, to maintain the dark background, the picture is the center of the narrow. The other is to expand the display, this method will be used to screen each pixel, but because the pixels are prone to distortion, so it will have a certain impact on the display. So in any case, the choice of LCD should pay attention to the resolution is not as big as possible, but the appropriate use.
At present, most of the flat panel display angle can reach 180 degrees, that is to say, can clearly see the contents displayed by the screen from any one direction. The LCD is different, it can be seen from the perspective of advanced technology or not. The brands on the market, such as ASUS, Samsung, LG and other products, but most of them point to reach this level of 170 degrees, and with wide viewing angle display can reach 178 degrees, with a 180 degree CRT has been very close to. Users in the use process once the perspective beyond its actual visual range, the color of the screen will decrease, dark, or even negative situation as a. It is likely that everyone is confused by PHILPS's ad actually LCD perspective is not great, but much smaller than the CRT, is a significantly weaker than CRT.
Visual area refers to the area of the screen that can be used to display the image in real applications. Because the size of the CRT display is actually the size of the picture tube, the portion of the image that can be used to display the image is simply not up to this size, because the frame of the kinescope occupies a part of space. In general, the 17 inch CRT display visual area of about 15.8-16 inches, while the visual area of the 15 inch display is only about 13.8 inches. But for LCD, the nominal size is basically a visual area the size of the border is a very small footprint, the visual area of 15 inch LCD about 14.5 inches or so, which is why LCD seems to cause more than the same size of CRT. So when you buy LCD 15 inches is basically enough.
LCD display function is mainly a backlight light source, the brightness of the light source determines the whole LCD screen brightness and color saturation. Outdoor highlight LCD screen outdoor LCD screen in theory, the brightness of the LCD is the higher the better, the brightness of the measurement unit is cd/m2 (per square meter candle), also known as NIT lumens. At present, most of the brightness of the TFT screen is started from the 150Nits, usually 200Nits can show a better picture. Contrast is the black and white two colors at different levels of contrast measurement. Contrast 120:1 can show vivid, rich color (because the human eye can be a contrast of about 100:1 or so), the contrast rate of 300:1 can support the color of each order. At present, most of the LCD display contrast in 500:1 ~ 800:1. And such as ASUS, Samsung, LG and other brands LCD display product contrast is generally reached about 1000:1. There is no set of fair value to measure the contrast between brightness and contrast, so buy LCD by a pair of sharp eyes. So when you want to pay attention to the purchase of this indicator LCD, it is also the biggest difference in the performance of LCD products on the ring to buy some of the estimated difficulty.
The unit of time to measure the response rate is MS, which means the time required for the pixel to light from dark to light. The smaller the value, the smaller the value, the faster the reaction. At present, the reaction speed of the mainstream LCD is more than 25ms, and it is not related to the general commercial use (such as word processing or text processing), because this kind of use does not have to care too much about the reaction time of LCD. And if it is used to play games, watch VCD/DVD full screen high dynamic image, the reaction time is especially important, if the reaction time is longer, the screen will appear tailing, incomplete and other phenomena. For a simple example, the vast majority of the market on the LCD display in the QUAKE3 will have a different degree of tailing phenomenon, especially when the picture is updated at high speed. The CRT is completely no problem, because the reaction time of CRT is only 1ms, is not a phenomenon of tailing.
When it comes to color, LCD is not comparable to CRT, in theory, CRT can display the same color as the tv. The LCD can only display about 260 thousand colors, the vast majority of products are claimed to be able to display 16 million 770 thousand colors (16777216, 32), but are in fact by dithering algorithm (dithering) to achieve, compared with the 32 bit true color is still a big gap, so in the color expressive and the transition is still less than the traditional CRT. In the same way, LCD's ability to perform grayscale is not as good as CRT. You can compare all possible: find a 17 inch Trinitron CRT display, and then put a 15 inch LCD image, a 16 million 770 thousand color display at the same time. The CRT display screen is very bright, but LCD is a bit "false", although can not say where is wrong, but that is not at Longguan comfortable CRT.