LED backlight refers to the use of LED (Light Emitting Diode) as the backlight of LCD screen. Compared with the traditional CCFL backlight, LED has the characteristics of low power consumption, low calorific value, high brightness and long life, and is expected to completely replace the traditional backlight system in recent years.
LED backlight can improve the color performance of LCD. LED light is generated by three independent LEDs, providing a color spectrum that is quite consistent with the color filter of LCD image points.
Extended data:
When people look at the screen, they want the higher the brightness and contrast, the better. Of course, the picture is more gorgeous and the details are better. Many manufacturers grasp the psychology of consumers, nominal brightness and contrast parameters.
In fact, products with brightness of 500 lumens and contrast ratio of 600: 1 or above can completely meet the viewing needs, and the best way is to feel it yourself.
In addition, the brightness uniformity of the screen is also very important, but it is usually not marked in the instructions of LCD TV products. Brightness uniformity is closely related to the number and configuration of backlight and reflector. A better quality TV has uniform brightness and no obvious bright areas. At this time, it is easier to capture uneven brightness when the picture is switched to a black screen state.
There are two ways to improve brightness: one is to improve the light transmittance of LCD panel; The other is to increase the brightness of the backlight.
The brightness of the mainstream is above 250cd/m2, but high-gloss products are gradually popularized. Generally speaking, a product with a CD/m2 of more than 400 is a bright spot. High brightness can make the displayed picture clearer and more vivid, especially suitable for playing DVD movies.
As for the comparison, the mainstream products are between 400∶ 1 and 500∶ 1, with little difference, but some high-end products are above 800∶ 1, so don't care too much when purchasing. The contrast is too high, for example, above 400, which is of little practical significance and can't be distinguished by human eyes.
References:
Baidu encyclopedia LCD TV