Evaluation standard and method of small spacing LED display screen

A small spacing LED display that is qualified and can stand the test must have been strictly tested before leaving the factory. Only in this way can we ensure the normal operation and good display effect for a long time and reduce the failure rate after being officially delivered to the customer.

Evaluation requirements for small spacing LED display

(1) LED display Gray image test

① The test of gray scale and color scale has always been an important index reference for DLP / plasma / LCD / LED large screen or splicing large screen, which is used to evaluate the gray scale transition ability of large screen splicing and controller (if any), as well as the black-and-white conversion ability. The more obvious the contrast, the stronger the ability of the display system to process color pictures.

The bidirectional gray scale signal is used to test the 16 level gray scale levels that the system should display at least. If each level can be distinguished, 3 points will be obtained; One point will be reduced if the resolution is less than one level, and the lowest score for this item is 0.

② Comprehensive test of sharpness and gray scale. This scenario is used to comprehensively test the performance of the whole system, such as line number, gray scale, geometric distortion and so on. At 1080p (1920) × 1080), each gray level and the number of lines shall be clearly distinguishable, and the black-and-white purity of gray level can be tested at the same time. If there is a problem, 1 point will be reduced; Minimum 1 point.

③ Gray scale real map. The more black-and-white levels are displayed, the better the gray-scale processing ability of the system can be reflected. Minimum 2 points, maximum 5 points.

(2)LED display Color picture test

① Color picture dark part comprehensive test. The scene is a night scene, which focuses on the intensity change of color light and shade and halo. It is used to test the color, gray, detail display and other performance of the system. If the left boat under the bridge and the top halo and bridge deck cable above the main tower can be clearly distinguished, 4 points will be given. Deduct 1-2 points depending on the severity of the problem. If there is no problem in distinguishing the light and shade changes of other details, 1 point will be added.

② Bright detail test: the detail restoration ability test with bright white as the tone. This scene is a dining table and dressing table with high brightness. It mainly tests the restoration ability and gray scale dynamic range of the white part of the system under high light. The grain details of window curtain, cloth, brush and other objects should be completely preserved. If all items are met, 5 points. In case of nonconformity, 0.5% will be deducted for each item 5 points, up to 2 points can be deducted in total.

③ Face detail definition test. The scene is a close-up static picture of a girl and flowers, reflecting the fidelity of the large screen splicing system to various details such as face color and spots, as well as the authenticity of skin color. The total score is 5 points. If the facial details are not clear, 0.5 point will be deducted 5 points. Deduct 1 point for impure facial color.

④ Color reduction test. It mainly tests the uniformity of color and the purity of white. It is very important to restore and display various ingredients and fruit colors in the kitchen, pure white crystals on the tray, the pen holder and wood grain of color pencils, grasslands and clouds. If white is impure, deduct 1 ~ 3 points depending on the color deviation purity. The full score is 5 points.