When consumer is buying LIQUID crystal TV, the following key index is very important:

The resolution of the

LCD TV resolution is fixed, unlike computer LCD, can adjust the resolution. LCD TV's fixed resolution is also its best resolution, high resolution can be easily compatible with HDTV. For any video signal that is not the best resolution of the LCD screen, the LCD TV needs to convert the image resolution and then display the conversion. To LCD TV character, resolution is one of important parameters. The resolution supported by traditional CRT TVS is more flexible, while LCD TVS have fixed pixel spacing, so they don't support as many display modes as CRT TVS. The optimal resolution, also known as maximum resolution, is the resolution at which the LCD TV displays the best image. LCD TV mainly 800×600, 1280×768, 1366×768 and 1920×1080 and other common resolutions.

The response time

The so-called "response time" is the response speed of the LCD screen to the input signal, that is, the response time of the LCD from dark to bright or from bright to dark. Obviously, the smaller the "signal response time" metric, the better. The smaller the response time is, the user will not have a feeling like residual shadow or drag when looking at the moving screen. Moreover, this point on the REQUIREMENTS of LCD TV than LCD monitor even higher.

Because computer monitor is used to do the static picture such as text, picture to show more time, the requirement of this index is not quite obvious. The shorter the signal response time, the better the display effect.

The data show that the response time is 30 milliseconds, and the TV can display 33 frames per second, which is enough to meet the needs of DVD playback. With a response time of 25 milliseconds, the TV can display 40 frames per second, which is perfect for DVD playback and most movies or games.

We are in the purchase of TV, to see the TV picture from multiple angles, such as in the Angle of the screen, and then offset some Angle, and to stand in the same horizontal position with the TV screen to see if you can see the image; In the machine test, you can also let promoters play some faster pictures, see whether the action is coherent, whether there is a phenomenon of screen tail.

interface

When buying, look not just at the surface, but also at the back of the TV ports, which directly affect your "investment protection", is very important. For LCD TV, good is the HDMI interface standard, the interface can transmit audio and video signals at the same time the digital interface, not only can simplify the connection, reduce the burden of attachment, and can provide huge digital signal transmission, the bandwidth required future disc machine, computer, home theater and other equipment, can actively using this interface, application of the interface to connect with these devices, Can get good results.

Considering that LCD TV should be connected with peripherals such as home theater and computer, in addition to the necessary AV and S-video interfaces, DVI and D-SUB interfaces, optical fiber output, etc., should also be within the scope of investigation.

Screen bad point

Bad spot problem is a big problem that perplex LCD TV set. Broken spots on LCD panels cannot be repaired, only replaced by LCD panels, which account for at least 70% of the cost of an LCD TV. Due to the limitation of manufacturing technology, there will inevitably be a bad point, which is commonly known as the "dead point". A bad dot can be a black dot, a green or a red dot. At ordinary times we are generally difficult to find, but sometimes very eyesore. After all, liquid-crystal manufacturing technology has yet to make a quantum leap, so even big companies can't be sure that their LCD products don't have a single bad spot. Identify the small dookey of LCD TV bad spot, window: consumer is testing a few monochromatic picture more when buying, notice the pixel point that has abnormal color next. An easy way to do this is to make the screen black and see if there are any bright spots in the pure black. Then make the screen all white to see if any black spots appear. Then switch to red, green and blue to check the integrity of the dots. If you find too many bad spots during the inspection, don't buy them.

Viewing Angle

When watching LIQUID crystal TV, still put in the problem of a visual Angle, when the visual Angle of the eye of the person and display screen is greater than certain Angle namely, cause picture to show not clear likely reach glance to spend big, see not clear picture. Therefore, the bigger the viewing Angle, the better it is to watch the TV picture from all angles. The recognized viewing Angle in the industry is 160 degrees to 170 degrees for up and down and left and right, at this Angle, you can determine the viewing needs of most occasions. A few new appear on the market liquid crystal TV visual Angle can achieve 176 degrees.

Luminance contrast

When people are looking at the screen, they want brightness and contrast to be as high as possible. Of course, such pictures are more gorgeous and details are better. Many manufacturers capture the consumer's psychology, nominal brightness and contrast parameter values. In fact, anything with a brightness of 500 lumens and a contrast of 600:1 or more will do just fine. The best way is to experience it yourself. In addition, screen brightness uniformity is also very important, but it is not usually noted in LCD TV product specifications. Whether the brightness is uniform or not is closely related to the number and configuration of backlight and reflector. TV with better quality has uniform brightness and no obvious bright area. This makes it easier to capture uneven brightness when the screen is switched to black.

There are two ways to improve brightness: one is to improve the light pass rate of LCD panel; Another is to increase the brightness of the backlight source.

The mainstream brightness is above 250cd/m2, but highlights are becoming more popular. Generally speaking, more than 400CD /m2 can be considered as a highlight product, high brightness can make the display picture more clear and bright, especially suitable for playing DVD movies.

As for the contrast problem, mainstream products are in the range of 400∶1 to 500∶1, the difference is small, but there are also some high-end products reach more than 800∶1, do not care too much when purchasing. A high contrast, above 400, for example, is of little practical significance and is indistinguishable to the human eye.

Resolution will affect the degree of clarity of the picture, the LCD color TV picture with high resolution is clear and exquisite, the edge of the picture is lively and sharp, the resolution is too low will make the picture rough, close view has obvious sense of grain. In general, the resolution of 1024×768 or above has the characteristics of high-definition TV.

Screen type

As a result of technology and craft, LCD screen is divided into PC screen and special AV screen, common PC screen cost should compare with size special AV screen cheap 1000 yuan above, performance is also inferior a lot of, use at PC or the LCD screen of notebook only commonly. Due to cost or procurement difficulties and other reasons, there are individual manufacturers to shoddy, which requires consumers to be particularly vigilant, to some particularly cheap LCD TVS to be especially careful.

The screen format

The ratio of screen width to height is called screen ratio. The screen scale of liquid crystal TV has 4∶3 and 16∶9 commonly two kinds. 16∶9 is a good format for the human eye, with a stronger visual impact. At the same time, the future digital TV display format will also use 16∶9 format. The 4:3 display format is suitable for analog TV signals, so it has advantages if it is mainly used to watch TV. It should be noted that many 16∶9 and 4∶3 TVS can be reformatted with menus, but this comes at the expense of wasted real estate. If it is mainly used for watching TV, it is recommended to choose a 4:3 product, otherwise the stretched image will make you unbearable. While mainly used to watch DVD movies, it is recommended to choose a 16∶9 product, because 16∶9 will bring a visual enjoyment that 4∶3 can not reach.

distance

Point distance generally refers to the distance between two adjacent pixels. The point distance is calculated by dividing the panel size by resolution, but it's not nearly as important for LCD TVS as it is for CRTS.

The reaction time

Alleged reaction time is the speed that LCD TV each pixel reacts to input signal, namely pixel by dark turn bright or by bright turn dark place the time that needs? The principle is to apply a voltage in the liquid crystal molecules, so that the liquid crystal molecules torsion and recovery. . Often said 25ms, 16ms refers to this reaction time, the shorter the reaction time, the user will not have the feeling of trailing shadow when watching the dynamic picture.

According to the data:

Reaction time 30 milliseconds =1/0.030= 33 frames per second, which can meet the needs of DVD playback;

Response time: 25ms =1/0.025= 40 frames per second, which is sufficient for DVD playback and most movies or games.

Backlit life

LCD panel itself can not emit light, it is a backlight display device. There is backlight in the backside of LCD screen, LCD TV is to rely on the LCD unit on the panel "block" and "open" the light that backlight gives out, will achieve restore picture.

It can be found that as long as the LCD is switched on, the backlight starts to work, even if the display is an all-black picture, the backlight will also remain working.

As a result of the transmittance of liquid crystal face plate extremely low, want to make the brightness of liquid crystal TV achieves the level of restore picture. The backlight brightness is at least 6000CD /m2. The life of backlight lamp is the life of LCD TV, the backlight life of general LCD TV is basically in above 50 thousand hours. In other words, if you use an LCD TV for an average of 5 hours a day, that 50 thousand hours of life is equivalent to 27 years of LCD TV use.

Receive standard

There are three main color TV systems in the world, namely NTSC, PAL and SECAM, but the three systems can not be unified. Pal-d system is adopted in China, so LCD TV used in China should be compatible with PAL-D system at least. General liquid crystal TV is compatible with the TV system of above, but confirm again before buying.

Sound output power

Liquid crystal TV to can normal sound, contain two built-in sound box at least so, what its power decides is sound box place can give out the loudest strong.

Because the main role of LCD TV is not to appreciate music, so the power of the sound is not very important, compared to the quality of the sound may be more important. Power of sound box of general liquid crystal TV is 2 arrive 10W.

Of course, if you need to connect an LCD TV to a home theater, the amplifier unit is not bypassed, so the LCD TV's sound output is negligible.