What should I pay attention to in the US purchase P3.91 indoor full color LED screen?

In addition to the thinner appearance of LED LCD TVs and ordinary LCD TVs, the easiest way to judge the two is to look at the product model. Generally speaking, LED-backlit LCD TVs are marked with "LE" or "LED" before the product model. Consumers still need to avoid some conceptual misunderstandings when purchasing LED LCD TVs.
 
First, don't pay too much attention to the backlight mode.
The backlight sources of LED LCD TVs are mainly divided into two types: side-type and direct-type. The side entry type is around each panel.
When installing the LED display screen, the light source should be illuminated from the side, and the generated light diffuses between the reflector behind the panel and the light guide plate, and then is transmitted to the screen. Direct-lit LED backlights are mostly positioned in high-end products, but because of the large number of LEDs and high cost, the volume and energy consumption are restricted.
In real applications, the two technologies have their own expertise, consumers do not need to pay too much attention to the backlight mode, just consider their purchasing power to meet their own needs.

Second, don't blindly pursue thinness.
The slim profile of LED-backlit LCD TVs is one of the important purchasing factors for consumers. The most important component of an LED-backlit LCD TV is the panel. We cannot blindly pursue thinness and neglect the choice of high-quality panels. Panels are mainly divided into VA soft screen and IPS hard screen. Compared with these two kinds of panels, the IPS hard screen further improves the stability of the LCD screen, so it has a stable picture, fast response time, higher dynamic picture quality, and viewing angle. Wide, small color distortion and other characteristics.
Third, look carefully at other parameters.
Each TV set lists many parameters when it is sold. It is recommended that consumers refer to the following indicators when buying.
1. Frequency. This is the same as an ordinary LCD TV. The higher the value, the less obvious the screen jitter. Generally it is 50～60HZ, the high is 100HZ, even 240HZ.
2. Response time. This point mainly depends on whether the tailing phenomenon is obvious when changing channels, which can be as fast as 4 milliseconds, and the general performance of 6 milliseconds and 8 milliseconds is also good. This is related to the chips used in the TV.

3. Contrast. Strictly speaking, contrast is the ratio of the brightness of the same point on the screen when it is the brightest (white) and the darkest (black). The higher the contrast, the more grayscale and richer colors the product can present. The contrast ratio of general LCD TVs varies from 600:1 to 1500:1.

These data are a "dynamic" contrast. The so-called dynamic contrast refers to the contrast value measured by the LCD TV under certain conditions. For example, test each area of the screen one by one, and use the contrast value of the area with the highest contrast as the product The contrast parameter. Therefore, consumers should not be misled by the propaganda of the merchant when buying.