Outdoor LED st7789 full-color display online automatic detection

Outdoor LED st7789 full-color display online automatic detection

The color difference or brightness difference in outdoor LED st7789s is caused by the inadequate control of a single module in the production process, but the lack of testing in the module process or the inability to implement 100% testing will bring uncertain factors to the quality of the entire screen after assembly. This article discusses the online automatic detection of outdoor LED st7789 modules, hoping to provide help for the development of the industry.

According to the inspection requirements of the outdoor LED st7789 module, the original manual inspection was transformed, and the system was designed to integrate machine vision technology into the inspection process of the LED module. The LED module was realized without changing the hardware of the LED module. The online, automatic, and rapid quality inspection of the LED module meets the inspection requirements of customers and realizes the standardization of module production. It will certainly have a larger application market in the field of rapid on-site inspection of LED unit boards. It is not only conducive to improving the economic efficiency of the enterprise itself, but also can promote the technological progress of the industry, promote the development of China\'s optoelectronic industry, improve the technical level of my country\'s industry, reduce and replace imports, and have significant economic benefits.

Develop a set of control system software to control the display pattern of the outdoor LED st7789 module, use a high-precision color brightness sensor probe to detect the brightness and chromaticity of the module, and then use the self-developed data acquisition and analysis software to determine the display module Whether the brightness and chromaticity uniformity is qualified, statistics and records are carried out, so as to realize the online automatic detection and industrialization of the brightness and chromaticity consistency of a large number of outdoor LED st7789 modules.

The principle of realizing the online detection of LED full-color screen modules is that the camera (including brightness and chromaticity probes) collects the luminous signal of the LED full-color display module on-site and the software analyzes the results in real-time. The camera brightness and chromaticity calibration are realized by standard luminance and colorimeter, as shown in Figure 1 below.

Outdoor LED st7789 design flow chart

(1) Outdoor LED st7789 module automatic positioning detection

The LED full-color display module automatically enters the online detection system through the assembly line and triggers the online detection system for detection after automatic positioning. The positioning system is also responsible for supplying power to the module and realizes the color conversion of the module under several conditions, such as plus or minus 45 degrees, 90 degrees, and so on. After the signal is stable, the detection system is triggered to test the brightness and chromaticity distribution.

(2) Outdoor LED st7789 brightness, chromaticity distribution detection, and quality classification

The LED full-color screen brightness and chromaticity distribution detection system is composed of a camera and a high-precision CCD. The camera can change lenses with different focal lengths as needed. The detection system collects image signals, and realizes the positioning of LED pixels through technologies such as image binarization processing and image threshold segmentation of histograms; uses the RGB color model in the image to calculate tristimulus values ​​for color coordinates, color purity, and correlated color temperature Equal chromaticity parameter calculation; convert the RGB color model used in the image into XYZ and YUV color models (Y represents brightness, U and V are the two components of color), and the brightness of each pixel can be calculated conveniently and quickly value. On this basis, the statistical analysis and processing of the uniformity of the brightness and chromaticity distribution of the full screen are carried out, and the quality of the screen is classified according to the production requirements to meet the requirements of the quality consistency of the control screen.

(3) Calibration of outdoor LED st7789 detection system

The response of the detection system composed of the camera and the high-precision CCD does not meet the requirements of the XYZ tristimulus color matching function in the chromaticity system, so the response signal must be calibrated to complete the chromaticity and brightness test requirements. The calibration of the LED full-color screen detection system is completed by a calibration system composed of a standard lamp, a standard spectrum colorimeter and a high-precision spectrometer. Use the standard signal generated by the calibration system to construct a mathematical model to establish the response function of the detection system corresponding to the color matching function of the XYZ tristimulus value. The model contains a series of response functions under different test conditions such as different lenses and different apertures, which can be automatically called in actual tests to achieve one-time calibration and continuous use. Simplify the complexity of use and greatly improve production efficiency.

The st7789 application

1.Information display: passenger flow in the scenic spot, publicity in the scenic spot, event announcements, broadcast announcements, etc.;

When there is a lot of traffic during holidays, the st7789 will play a bigger role. The RISINGLCD st7789 can show scenic spots, release warm reminders, real-time environmental monitoring information, temperature reports, etc., which not only allows scenic visitors to take the lead in enjoying the beauty of the scenery but also makes playing more convenient, safe and enjoyable.

2. Performing stage beauty: folklore art performances, presenting wonderful moments;

Now the scenic spots will fully excavate local art and folk culture to produce rich programs to attract tourists. RISINGLCD st7789 makes full use of its excellent video playback function and color display effect. The stage is designed with a st7789, a flexible and changeable background, and the sound and light effects of the stage are also true and magical. It brings a strong visual impact to the visitors, makes the audience feel immersive, and allows visitors to appreciate the strong Regional style stage performances.

3. Inquiry and interaction: practical interactive screens in scenic spots;

For example, query maps, tour routes, watch introductions to scenic spots, conduct interactive visits, and other rich activities (query interaction). At present, the RISINGLCD st7789 has been widely used. Ticket collection machines, inquiry machines, etc. all use the Internet + cultural tourism to realize the conversion from offline to online and increase user retention.

RISINGLCD st7789 relies on the advantages of excellent performance, ultra-high price, spot supply, and localized services. The installation of S-LCD displays in scenic spots has become a trend and trend in the development of smart tourism. In the future, S-LCD displays will undoubtedly have more room for development and penetrate into more application areas in scenic spots.

The st7789 supplier

RISINGLCD (WITH BRAND OF RISING STAR) is a professional highlight LCD manufacturer from China, as a superior global supplier, a modernized high-tech enterprise with 100 employees including 20 highly qualified and well-trained engineers. Due to our 2, 000 square meters’ factory and a monthly production capacity of 10, 000 pieces, we can meet your demands. Specializes in manufacturing and distributing all types of LCD modules, LCD monitors, LCD digital signage, Touch Screen, etc. Now our products have been widely used in games, finance, communication, electricity, transportation, hospitals, estates, travel and government lines, stations, 4S shops, museums, exhibitions, libraries, hotels, and entertainment KTV. Our markets cover Asia, North America, Africa, the Middle East, Europe, Central, and South America, and Oceania. For more information about LCD, welcome to contact us via: risinglcd@foxmail.com

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