1. flatness: the surface smoothness of the led display screen should be within (+1 mm) to ensure that the display image does not distort. local protrusion or concavity will lead to the dead angle of the visual angle of the led video display screen. flatness is mainly determined by production process.
2. brightness and visual angle
the brightness of indoor full-color screen should be more than 800 cd/m2, and that of outdoor full-color screen should be more than 1500 cd/m2, so as to ensure the normal operation of the display screen. otherwise, the display image will not be visible because the brightness is too low. the brightness is mainly determined by the quality of the led core.
the size of visual angle directly determines the audience of the display screen, so the bigger the better. the size of the visual angle is mainly determined by the encapsulation method of the core.
iii. white balance effect
white balance effect is one of the most important indicators of display screen. in color science, when the ratio of red, green and blue is 1:4.6:0.16, pure white will appear. if there is a deviation in the actual ratio, there will be a deviation in the white balance. generally, we should pay attention to whether white is biased towards blue or yellow-green. the quality of white balance is mainly determined by the control system of the display screen, and the core of the tube also has an effect on the reducibility of the color.
iv. reductivity of colour
the reducibility of color refers to the reducibility of the display screen to the color. the color displayed by the display screen should be highly consistent with the color of the playback source, so as to ensure the authenticity of the image.
5. is there a mosaic or a dead-point phenomenon?
mosaic refers to a small square on the display screen, which is usually bright or dark. the main reason is that the quality of the plug-in program used in the display screen is not good enough.
dead point refers to a single point on an led display that is often bright or dark. the number of dead points is mainly determined by the quality of the tube core.
6. colored block or not
the color block refers to the obvious color difference between adjacent modules. the color transition is based on modules. the phenomenon of color block is mainly caused by poor control system, low gray level and low scanning frequency.