The main test items for indoor small-pitch LED displays under the T/COEMA 101S-2017 standard include the following:
Aspect Ratio: Tests whether the physical dimensions of the display screen meet design requirements, ensuring no image distortion.
Assembly Accuracy: Evaluates the uniformity of gaps, flatness, and alignment accuracy between modules when splicing multiple displays, ensuring a seamless display effect.
Maximum Brightness Non-uniformity: Measures the percentage difference in brightness between different areas of the display screen at maximum brightness, reflecting brightness consistency.
Low Brightness Non-uniformity: Tests the uniformity of brightness distribution under low brightness conditions, avoiding obvious bright spots or dark areas at low brightness.
Black Screen Non-uniformity: Tests the uniformity of the background when the display screen is completely off, eliminating light leakage or dark spot problems.
Chromaticity Non-uniformity: Evaluates the color consistency of different areas of the display screen, ensuring no local deviation in color reproduction.
Frame Switching Frequency: Tests the rate at which the display screen switches frames, measured in Hz, affecting the smoothness of dynamic images.
The highest contrast ratio measures the ratio of the screen's brightness at its brightest to its darkest state, reflecting the image's depth and detail.
Brightness discrimination level tests the smallest difference in brightness that the human eye can distinguish; a higher value indicates more nuanced brightness levels.
Maximum brightness measures the screen's highest brightness value at full white, measured in cd/m².
Signal processing depth assesses the screen's ability to process input signals in bits (e.g., 8-bit, 10-bit), affecting the naturalness of color transitions.
Grayscale level tests the number of grayscale levels the screen can display; a higher value indicates smoother color transitions.
Refresh rate measures the number of times the screen refreshes its display per second, measured in Hz, affecting image stability.
Low brightness, high grayscale, and high refresh rate test the compatibility of high grayscale levels and high refresh rates under low brightness conditions, ensuring clear details in dark areas.
Pixel failure rate measures the proportion of out-of-control pixels (constantly bright, constantly dark, or with abnormal colors) out of the total pixels, reflecting the manufacturing process level.
Color coordinates measure the chromaticity coordinates (e.g., x, y values) of the colors displayed on the screen, ensuring that colors conform to standard ranges.
Viewing angle distribution testing measures the visible angle range in both horizontal and vertical directions. Brightness or color attenuation beyond this range must meet standards.
Coupling effect assessment evaluates the degree of electrical or optical interference between adjacent modules when multiple displays are spliced together, ensuring no abnormal interaction effects.
Standard applicability notes: The T/COEMA 101S-2017 standard is specifically designed for indoor small-pitch LED displays (pixel pitch ≤ 2mm), focusing on core indicators such as high resolution, seamless splicing, and low-brightness performance. It is suitable for scenarios with stringent display quality requirements, such as broadcasting, conferences, and exhibitions. The test items comprehensively cover optical, electrical, structural, and reliability dimensions, providing quantitative basis for product quality control.
