Backlight is to adjust the brightness of the LCD TV backlight; brightness is to adjust the opening and closing of the LCD TV glass, and adjusting brightness is to adjust the brightness of the picture.

LED backlight refers to the use of LEDs (light-emitting diodes) as the backlight source of LCD screens. Compared with traditional CCFL (cold cathode tube) backlights, LEDs have the characteristics of low power consumption, low heat generation, high brightness, and long life, and are expected to completely replace traditional backlight systems in recent years.

LED backlight can enhance the color performance of LCD display. LED light is generated by three separate LEDs, providing a color spectrum that closely matches the LCD image point color filter itself.

Extended information:

When people look at the screen, they all hope that the brightness and contrast are as high as possible. Of course, this will make the picture more vivid and the details better. Many manufacturers have seized on this psychology of consumers and set nominal brightness and contrast parameter values.

In fact, products with a brightness of 500 lumens and a contrast ratio of 600:1 or above can fully meet the viewing needs. The best way is to experience it yourself.

In addition, the brightness uniformity of the screen is also very important, but it is usually not marked in LCD TV product specifications. Whether the brightness is uniform or not is closely related to the number and configuration of backlights and reflectors. A better-quality TV will have uniform brightness and no obvious bright areas. This makes it easier to capture uneven brightness when switching the screen to a black screen state.

There are two ways to increase brightness: one is to increase the light transmittance of the LCD panel; the other is to increase the brightness of the backlight source.

The mainstream brightness is above 250cd/m2, but high-brightness products are gradually becoming popular. Generally speaking, a product with a brightness of 400cd/m2 or above is considered a high-brightness product. High brightness can make the displayed picture clearer and more vivid, and is especially suitable for playing DVD movies.

As for the contrast issue, mainstream products are all between 400:1 and 500:1, and the difference is small. However, there are also some high-end products that reach 800:1 or above, so you don’t need to worry too much when purchasing. A contrast ratio that is too high, for example, if it is above 400, has little practical significance, and the human eye can no longer distinguish.

Reference: Baidu Encyclopedia LCD TV