How to buy (choose) a better LCD TV
Now that the prices of flat-screen TVs continue to fall, ordinary families have already included the purchase of LCD TVs in their family plans. So, what should we pay attention to when buying LCD TVs? In view of the current development of LCD TVs, we In particular, this must-see material for buying LCD TVs is released. I hope you can understand some of the knowledge you should know before buying LCD TVs, which will help your purchase plan.
1. The display principle of LCD TV
Let's first understand the display principle of LCD TV. A brief understanding of this knowledge will help ordinary users to eliminate some misunderstandings of LCD TV and prevent manufacturers from misleading advertising.
The LCD TV uses the principle of liquid crystal to emit light under the effect of voltage. There are three kinds of liquid crystals that make up the screen: red, green and blue, called the three primary colors. They are arranged in a certain order, and these liquid crystals are stimulated by voltage to show different colors, and different proportions of the mix can show kaleidoscopic color. The response time of each point change will affect whether the screen is tailing, usually the faster the response time, the better. Because the LCD TV uses dot imaging, the more dots formed on the screen, the finer the imaging effect. The vertical and horizontal dots constitute the resolution of the LCD TV. The higher the resolution, the better the effect.
Second, how to determine a suitable purchase size
Generally speaking, we rely on the size of the room and the viewing distance to determine the size of the flat-screen TV. In fact, we should mainly choose the purchase size based on the viewing distance. An alternative parameter for size. The recommended reference is: the straight-line distance within three meters, the room size is more than 20 square meters, choose 25-29 inches; the straight-line distance about three meters, the room size is 20-30 square meters, choose 29-34 inches; about four meters For the straight-line distance, the room size is 30-40 square meters, choose 35-43 inches; for the straight-line distance of more than four meters, the room size is more than 50 square meters, choose the LCD TV more than 43 inches.
The viewing distance recommended by the state is generally about 3 times the diagonal size of the TV.
3. The status of domestic flat-panel TV warranty that must be understood
At present, there is no inspection warranty standard for LCD TVs in China. The maintenance standard of LCD TVs refers to the standard of LCD monitors, that is, one-year free warranty is provided, rather than the three-year free warranty provided by the state on the TV three guarantees. In fact, many CRT TVs are now available. Manufacturers have implemented a five-year warranty, and now the standard for buying LCD TVs is relatively backward. Now some brands and home appliance chains have jointly launched a two-year warranty commitment. Before buying, consumers should ask the warranty details in detail, because the cost of LCD TVs is higher, and the problems often occur on the LCD panel. The value of the LCD panel will account for about two-thirds of the entire TV. If you need to pay for repairs yourself, the cost is quite huge.
4. LCD TV is not equal to HD TV
LCD TV and HDTV are two completely different concepts. It is quite wrong to think that buying LCD TV means buying HDTV. There is no clear standard for high-definition television in China at present. The standard generally used is the international HDTV standard. The international HDTV standard is 1280 × 720 (non-interlaced, field frequency is 24, 30 or 60), 1920 × 1080 (Interlaced, field frequency 60) and 1920 × 1080 (non-interlaced, field frequency is 24 or 30) three display modes, that is, we often say three kinds of 720P, 1080i and 1080P, only reach these three display modes The LCD TV is the HDTV. At present, the CCTV digital high-definition channel uses the 1080i signal mode source. Generally speaking, we do not have to buy products that support 1080P, because the products that support 1080P are relatively expensive now.
5. LCD TV still needs a set-top box to watch digital TV
Now that CCTV's digital high-definition channels have been broadcast in some areas of the country, many consumers mistakenly believe that they have bought an LCD TV and can watch digital high-definition channels without a set-top box. Although the role of the set-top box is to convert digital signals to analog signals, and the LCD TV will convert the analog signals to digital signals for display, but the processing between their conversions is different. The LCD TV cannot directly receive the TV signals of digital high-definition channels. You still have to switch through the set-top box to watch it. LCD TVs with built-in set-top boxes are still in the research and development stage, and the set-top boxes in different regions are also different. I believe it will be a long time before we can actually buy LCD TVs that can directly watch digital HD channel TV signals. It is now impossible. of.
6. Treat the problem that LCD TV is not as good as CRT when watching ordinary TV programs
Many consumers who have bought LCD TVs may have such a confusion. Obviously they watched a good LCD TV in the mall before buying. Why did they feel that the effect of watching TV after buying it was not as good as the previous CRT TV?
The reason for this phenomenon is that when buying in the mall, consumers see the effect of playing the demo disc, and the picture will definitely be no problem, and the 16: 9 ratio of the LCD TV and the 4: 3 ratio of the ordinary TV signal are There are differences in aspect ratio. When watching ordinary TV signals, LCD TVs generally have two display methods. One is to display in a 4: 3 mode. Then a large section of black borders on the display screen must be used to fill in the difference in screen size. Another way is to use the conversion calculation to convert the 4: 3 picture to the 16: 9 picture. This approach will definitely cause the picture effect to drop when we watch, so when watching ordinary TV signals, LCD TV is not as good as traditional CRT TV. So far, only Sharp's latest AQUOS series LCD TVs use the PAL system to broadcast signals, which can provide the best display effect when receiving traditional analog TV signals.
7. Some problems that should be paid attention to when buying LCD TV
1. Pay attention to whether it has an HDMI interface
The HDMI interface is now the only digital interface that can simultaneously transmit audio and video signals. It not only simplifies the connection and reduces your connection burden, but also provides a huge bandwidth for digital signal transmission. Emphasizes the importance of this interface The main reason is that new and future devices such as disc players, computers, home theaters, etc. will actively use this interface, and applying this interface to connect with these devices will undoubtedly obtain the best results. Therefore, confirm whether you need an HDMI interface before purchasing, which can reduce the chance of regret after your purchase.
2. Note the actual resolution
The actual resolution of the LCD TV refers to the resolution that the LCD TV itself can achieve. Generally, you should choose a resolution of 1280 * 768 or higher. Products that achieve this resolution or higher will be better when watching HD TV and multimedia terminals as computers. Many, it should be noted that some manufacturers blind compatible consumers with compatible signal input, and must distinguish between the actual resolution and compatible signal input. Also due to the working principle of the LCD, the resolution of the LCD TV is fixed, and its optimal resolution is its actual resolution, and when we connect to the computer, it is best to choose the resolution closest to the LCD TV Resolution setting. At present, LCD TVs mainly have several common resolutions such as 800 × 600, 1280 × 768 and 1366 × 768.
3. Brightness, contrast, viewing angle
Manufacturers often exaggerate the brightness and contrast. Generally speaking, products with a brightness of 500 lumens and a contrast of 600: 1 or more are good. In fact, consumers can directly ignore the brightness and contrast parameters provided by the manufacturer (too fake), and directly focus on their own visual experience. The method is to check the brightness and contrast of the screen display at a distance of 5 meters away. Pay attention to some dark scenes. For details, compare a few more products. After that, you will know whether the LCD TV you will buy will satisfy you in terms of brightness and contrast. The viewing angle of the current LCD panel is generally above 170. The problem to be noted is that when viewing from the side, pay attention to whether the screens on the left and right and the center of the screen are clear, whether the brightness difference is large, and choose the product with the smallest difference.
4. Response time
After understanding the working principle of the LCD TV, you should know that this parameter is very important for the display effect of the LCD TV. Generally speaking, the faster the reaction time is, the greater the benefit for eliminating the smearing and afterimage phenomenon of the LCD TV. But this is also a comprehensive thing, it will also depend on the manufacturer ’s algorithm, and the optimization of the manufacturer ’s algorithm will also have a great impact on the elimination of smearing and afterimages. Look at the effect of actually playing action movies before buying. Confirmation is probably the best guarantee.
5. Dead pixels and highlights
The easiest way to check the LCD TV for bright spots is to make the screen completely black. At a distance of about 30 cm from the LCD TV screen, see if there are bright spots in the black. Then make the screen completely white to see if there is any dead spot. Then change to red, green, and blue to check the integrity of the color point. Check whether the brightness of the picture is uniform at a distance of about 2.5 meters. These checks should make sure that the whole screen is one piece. Solid color. Resolutely do not have problems. Why do you say that several bad points are allowed internationally? It is incredible that individuals firmly oppose this gangster logic and spend the same money. If others use good ones, I use bad ones.
Summary: If you want to buy a satisfactory LCD TV, do not go to the parameters and advertisements of superstitious manufacturers. After understanding the knowledge introduced above, the most important thing is that you should mainly focus on the feelings you actually watch. Several times, compare the actual results, and really know what you are thinking.
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