LED display is one of our common large screens. As the most promising display product in the future, since 2008, LED screens have demonstrated many functions and effects in just a few years. Nowadays, no matter Whether outdoors or indoors, LED displays have been recognized by people. Regarding the production of LED display screens, as a customer, how should we set an acceptance standard for the display screen?

1. Screen appearance inspection

Detection method: Visual inspection and hand feel can initially tell whether there is a problem with the LED screen.

1. Coating adhesion: there should be no shedding (including intersections)

2. Is the color consistent, or is there a color cast, or even a lack of brightness? The color is consistent with the sample (there is no obvious color difference when observed under natural light or fluorescent lamps with normal vision), and there is no color difference among products from the same batch (note: color difference includes color and gloss); the coating surface is smooth, flat, and uniform, and the surface must not have the following defects: No re-sticking, particles, leakage, pitting, blooming, wrinkles, or mechanical damage after drying;

3. Silk screen appearance: The screen printing content should be clear, complete, uniform in color, without burrs, defects, tailings, or contamination; the specific content, location, pattern, and font size of all silk screen printing should be described in detail by the corresponding drawings, and the manufacturer must strictly follow the instructions. The drawing design requires silk screen printing.

2. LED display box inspection

Testing method: Actual testing testing tools: vernier caliper, tape measure, level.

Requirements: Inspectors must strictly follow the designer’s drawings to inspect the incoming materials for the display cabinet one by one to check whether there are any missing or missing processed parts. When inspecting the cabinet, pay attention to the following issues:

1. The size deviation of the LED cabinet should not be greater than 0.5mm, and the difference between the two diagonals should not be greater than 1mm.

2. Check whether burrs are removed, whether sharp corners are blunted, and scratching or pricking of hands is not allowed.

3. Each nut and nut column must be threaded back to ensure that the screw can be locked in smoothly.

4. Check whether the overall assembly requirements of the box are faithfully processed according to the drawings. All accessories (such as locks and hinges) must use existing standard parts, and their mechanical strength and sealing performance must be ensured during assembly.

5. The welding of each welding joint of the box must be firm, without any welding, missing welding, etc. The welding points must be ground flat, the welding seams must be scraped, and the processing technology must be strictly standardized. The welds must be polished, sealed and waterproof, smooth and flat without sharp corners.

6. After punching and welding the LED module holes, the flatness of the front should be ensured. The surrounding panels should not be warped or deformed, and the flatness error should be less than 1MM. The size of the positioning holes on the front panel of the box should be strictly controlled, and the hole diameter and hole spacing should be strictly controlled. The error is less than 0.1mm; the X and Y directions of the hole axis should be on the same straight line, and the straight lines should be perpendicular to the edge of the box, with a perpendicularity of less than 1mm.

3. Display effect inspection

1. Color restoration

Color restoration refers to the display's ability to restore colors. Generally speaking, it means that the color displayed on the display must be highly consistent with the color of the original video, so as to ensure a high degree of image restoration.

2. Is there any color block on the display screen?

Color blocks refer to the obvious color differences between adjacent modules of the display screen. The color is excessive in units of modules. The main reason for the color blocks is that the control system of the LED display screen is poor and its gray level is not high. , caused by low scanning frequency.

3. Whether there is mosaic and dead center

Mosaic refers to the four square blocks that appear on the LED display that are always bright or black, mainly caused by module necrosis; dead spots refer to the single light spots that are always bright or black on the LED display, and how many dead spots there are. It is determined by the quality of the LED display tube.

4. Display brightness and viewing angle

The brightness of the indoor full-color LED display must be above 800cd/㎡, and the brightness of the outdoor full-color LED display must be above 1500cd/㎡ to ensure the normal operation of the LED display. Otherwise, the brightness will be too low and the image cannot be seen clearly. Or the brightness is too high and looks dazzling. The brightness of the LED display is mainly determined by the quality of the LED tube, while the viewing angle is determined by the packaging method of the tube. The larger the viewing angle, the greater the audience.

5. Flatness

The surface flatness of the display screen must be within ±1mm to ensure that the displayed image is not distorted. Local bulges or recesses will cause blind spots in the viewing angle of the display screen. The gap between the cabinet and the module and between the module and the module should be within 1mm. If the gap is too large, the borders of the display will be obvious and the screen will be visually uncoordinated. The quality of flatness is mainly determined by the production process.

6. Display stability

Stability refers to the reliable quality of the LED display during the aging stage after it is made into a finished product. You can ask the manufacturer for aging records to determine the conditions that occurred during the aging of the screen.

4. Safety performance and packaging and transportation inspection

1. Security

The LED display screen is composed of multiple boxes. Each box must be grounded for external customer protection, and the grounding resistance should be less than 0.1 ohm. And it can withstand high voltage, 1500V without breakdown for 1 minute. Warning signs and slogans must be placed at the high-voltage input terminal and power supply high-voltage wiring.

2. Packaging and transportation

LED display screens are valuable goods and weigh a lot, so the packaging method used by the manufacturer is very important. Generally, they are packaged in a single box. Each side of the box must be protected by protective materials to act as a buffer. There is not much room for movement inside the box during transportation. The outer packaging box must be clearly marked.

The above four points are the basic acceptance points and the most direct acceptance direction. Every suitable LED display must go through design, production, and aging testing before it can be put on the market.