How to choose a better LCD TV

How to choose a better LCD TV

Now with the continuous decline in the price of flat-panel TVs, many ordinary families have included the purchase of LCD TVs in their family plans. So, what should we pay attention to when buying an LCD TV? In view of the current development of LCD TVs, we have specially launched this must-read information for buying LCD TVs. We hope that you can understand some knowledge you should know before buying an LCD TV, which can help your purchasing plan.

1. Display principle of LCD TV

Let's first understand the display principles of LCD TVs. A brief understanding of this knowledge will be helpful for ordinary users to eliminate some misunderstandings about LCD TVs and prevent misleading advertisements from manufacturers.

LCD TVs use the principle of liquid crystals emitting light and forming images under the action of voltage. There are three types of liquid crystals that make up the screen: red, green, and blue, called the three primary colors. They are arranged in a certain order. By stimulating these liquid crystals with voltage, different colors can be presented. The combination of different proportions can present a myriad of ever-changing colors. The speed of the reaction time of each point change will affect whether the picture is trailing. Generally, the faster the reaction time, the better. Because LCD TVs use point imaging, the more points there are in the screen, the finer the imaging effect. The number of vertical and horizontal points constitutes the resolution of the LCD TV. The higher the resolution, the better the effect.

2. 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, the viewing distance should be the main factor in choosing the size. However, in order to make the home layout more coordinated, the room size can be used as an alternative parameter to determine the size. The recommended reference is: within a straight-line distance of three meters, the room size is less than 20 square meters, choose 25-29 inches; about three meters straight-line distance, the room size is 20-30 square meters, choose 29-34 inches; about four meters straight-line distance, the room size is 30-40 square meters, choose 35-43 inches; more than four meters straight-line distance, the room size is more than 50 square meters, choose a 43-inch or larger LCD TV.

The national recommended viewing distance for television is generally about 3 times the diagonal size of the TV.

3. The current status of domestic flat-panel TV warranty that must be understood

At present, there is no quality assurance standard for LCD TVs in my country. The repair standard of LCD TVs refers to the standard of LCD monitors, that is, one year of free quality assurance is provided, rather than the three-year free quality assurance stipulated by the state on TV three guarantees. In fact, many CRT TV manufacturers now implement a five-year quality assurance. The quality assurance standard for buying LCD TVs is relatively backward. Now some brand manufacturers and home appliance chain stores have jointly launched a two-year quality assurance commitment. Before purchasing, consumers should inquire about the quality assurance in detail, because the cost of LCD TVs is relatively high, and the problems often occur on the LCD panel. The value of the LCD panel accounts for about two-thirds of the entire TV. If you need to spend money on repairs, 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 an LCD TV means buying an HDTV. my country does not have a clear HDTV standard yet. 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 is 60) and 1920×1080 (non-interlaced, field frequency is 24 or 30) three display modes, which are often called 720P, 1080i and 1080P. Only LCD TVs that reach these three display modes are HDTVs. At present, CCTV Digital HD Channel uses the 1080i signal mode source. Generally speaking, we don’t have to buy products that support 1080P, because the price of products that support 1080P is still relatively expensive.

5. LCD TV still requires a set-top box to watch digital TV

CCTV's digital high-definition channels have been launched in some areas of China. Many consumers mistakenly believe that they can watch digital high-definition channels without a set-top box after buying an LCD TV. This is incorrect. Although the function of a set-top box is to convert digital signals into analog signals, and LCD TVs convert analog signals into digital signals for display, their conversion processes are different. LCD TVs cannot directly receive TV signals from digital high-definition channels and must still be converted through a set-top box before they can be watched. LCD TVs with built-in set-top boxes are still in the research and development stage, and set-top boxes in different places are also different. I believe it will take a long time before we can really buy an LCD TV that can directly watch TV signals from digital high-definition channels. It is impossible now.

6. Correctly deal with the problem that LCD TVs are not as good as CRT TVs in watching ordinary TV programs

Many consumers who have bought LCD TVs may have such a confusion: the LCD TVs looked very good in the mall before buying, but why do they feel that the TV effect is not as good as the old CRT TV after buying it home?

The reason for this phenomenon is that when buying in the mall, consumers see the effect of playing the demo disc, and there will definitely be no problem with the picture. However, the aspect ratio of the 16:9 display ratio of LCD TV and the 4:3 ratio of ordinary TV signals are different. When watching ordinary TV signals, LCD TV generally has two display methods. One is to display in 4:3 mode, so the display screen has to use a large black border to fill the gap caused by the different picture size comparison. The other method is to use conversion calculation to simulate the 4:3 picture into 16:9 picture. This approach will definitely cause the picture effect to deteriorate when we watch it, so it is normal that the effect of LCD TV is not as good as that of traditional CRT TV when watching ordinary TV signals. So far, only Sharp's latest AQUOS series LCD TVs use PAL format to play signals, which can provide the best display effect when receiving traditional analog TV signals.

7. Some issues you should pay attention to when buying an LCD TV

1. Check whether it has an HDMI interface

HDMI is the only digital interface that can transmit audio and video signals at the same time. It can not only simplify the connection and reduce your connection burden, but also provide a huge bandwidth required for digital signal transmission. The importance of this interface is mainly because new and future disc players, computers, home theaters and other equipment will actively adopt this interface, and using this interface to connect with these devices will undoubtedly achieve the best results. Therefore, confirm whether you need an HDMI interface before purchasing, which can reduce the chance of regret after your purchase.

2. Pay attention to the actual resolution

The actual resolution of an LCD TV refers to the resolution that the LCD TV itself can achieve. Generally, a resolution of 1280*768 or higher should be selected. Products that reach this resolution or higher will have much better effects when watching high-definition TV and serving as multimedia terminals for computers. It should be noted that some manufacturers use compatible signal inputs to deceive consumers. It is important to distinguish the difference between actual resolution and compatible signal input. In addition, due to the working principle of LCD, the resolution of an LCD TV is fixed, and its best resolution is its actual resolution. When we connect it to a computer, it is best to select a resolution setting that is closest to the resolution of the LCD TV. Currently, LCD TVs have several common resolutions, including 800×600, 1280×768, and 1366×768.

3. Brightness, contrast, viewing angle

Manufacturers often exaggerate on brightness and contrast. Generally speaking, products with a brightness of 500 lumens and a contrast ratio of 600:1 or above are considered good. In fact, consumers can ignore the brightness and contrast parameters provided by manufacturers (too fake) and rely on their own visual experience. The method is to check the screen display brightness and contrast from a distance of 5 meters, pay attention to the details in some dark scenes, and compare several products. In this way, you will know whether the LCD TV you are going to buy can satisfy you in terms of brightness and contrast. The viewing angle of current LCD panels is generally above 170. The problem that needs to be paid attention to is that when watching from the side, pay attention to whether the pictures on the left, right and center of the screen are clear, whether the brightness difference is large, and choose products with as small a difference as possible.

4. Reaction time

After understanding the working principle of LCD TV, you should know that this parameter is very important for the display effect of LCD TV. Generally speaking, the faster the response time, the greater the benefit in eliminating the tailing and afterimage phenomena of LCD TV. However, this is also a comprehensive thing. It will also depend on the manufacturer's algorithm. The optimization of the manufacturer's algorithm will also have a great impact on eliminating the tailing and afterimage phenomena. Looking at the actual effect of playing action movies before purchasing and confirming it with your own eyes may be the best guarantee.

5. Bad pixels and bright pixels

The easiest way to check if there are bright spots on an LCD TV is to make the screen completely black, and then stand about 30 cm away from the LCD TV screen to see if there are bright spots in the black. Then make the screen completely white to see if there are any bad spots. Then switch to red, green, and blue to check the integrity of the color points, and stand about 2.5 meters away to see if the brightness of the picture is uniform. These checks should be done to ensure that the entire screen is a pure color. If there are any problems, don't accept them. Why do you say that a few bad spots are allowed internationally? I personally strongly oppose this kind of bandit logic. It's incredible that I use a bad one while others use a good one for the same money.

Summary: If you want to buy a satisfactory LCD TV, don't be superstitious about the manufacturer's parameters and advertisements. After understanding the knowledge introduced above, the most important thing is to base it on your actual viewing experience. Watch it several times before buying, compare the actual effects, and really have a clear idea in your mind.