Key Factors to determine Quality of LED screens

General introduction

A light-emitting diode (LED) is a semiconductor device. You can see it as an electronic device that permits current to flow in one direction. And it illuminates when electricity passes through it. How to appraise a good led screen depends on the many elements.

White balance effect

During the screen debugging process, there is an adjustable white balance. So let's look at what is white balance.

The LED screen white balance effect is one of the most important indicator in the LED screen. Chromatics taken in the proportion of red, green and blue colors will show 1:4.6:0.16 pure white, if the actual proportion of the deviation of the white balance of a little deviation occurs, and generally pay attention to whether the white bluish, partial yellow-green phenomenon. The white balance is good or bad by the display control system, the die also have an impact on the reduction of color.

White balance is not defective screen, changing the color and brightness without affecting the white purity, what does not appear cast, but will not have other variegated doping which, as a large screen for a high-end dedicated display purposes, even if it is very small, "cast" will affect the picture color quality.

The led screen is composed by a large number of LED lamps. White balance consistency problems are quite common, which is the industry often encounter difficult problems.

Display device manufacturers require suppliers to provide 5nm wavelength range and 1:1.3 brightness range of the LED device supplier by these indicators through color separation machine reaches the voltage grading consistency generally not required. Typically, full-color display is composed of numerous red, green and blue LED components makes up a pixel for each color LED brightness, wavelength determines the consistency of the display brightness uniformity, white consistency and color degree of consistency. Generally. LED brightness differences in the brightness range of 1:1.3, blue, green and red wavelength difference is less than 5nm wavelength difference is less than 3nm this lamp composed screen (LED Screen other conditions perfect) will be the opposite conditions were fairly good balance consistency the screen may appear blurred screen, consistent bad results.

White Balance

 

Flatness

LED screen surface flatness to within ± 1mm. To ensure that the displayed image is not distorted, partial raised or recessed will lead to the screen viewing angle of dead ends. The quality of flatness is determined mainly by the production process.

Flatness

 

Brightness and viewing angle

Indoor full color LED screen brightness in 800cd/m2 above and outdoor full color LED screen brightness to 1500cd/m2 above in order to ensure the normal work of the LED screen. Otherwise it will not see the displayed image. The viewing angle of audience directly determines the size of the viewing angle of LED screen.

In different environment condition, the request brightness of LED screen are different according to the environment contrast ratio.

Indoor LED screen request a lower brightness but high request for viewing angle. Outdoor LED screen's brightness is higher than environmental brightness, and also with better grey degree, therefore its viewing angle request is not as high as indoor LED screen, generally between 35-- 50 degree.

If the viewing angle of LED lighting part become lower, the brightness will be higher. Vice versa. If the contrast ratio between LED screen's brightness and environmental brightness is higher, the LED screen's showing performance will be more colorful.

Viewing Angle

 

Refresh rate

Refresh is a very important parameter for LED screen, especially in TV studio. If low refresh rate there will be scan lines in the image when the camera shoots on it, and the audience will see the flicker though the camera. Usually the refresh rate ≥1000Hz, some high standard application need 3000Hz or more.

Refresh Rate

 

No mosaic and dead LED

Mosaic is square in the LED screen that always on or off, also means broken modules, mainly because broken cable or connector. Dead LED is the pixel in the LED screen always on or off, and it’s mainly determined by LED chips are used.

Dead LED