With the continuous expansion of the application range of full-color LED display screens and the continuous extension of the application fields, people's quality of LED full-color display screens is getting higher and higher. So for high-quality LED displays, what do manufacturers need to do?
At present, according to my country's LED display industry standard "General Specification for LED Display SJ/T11141" and "Electronic Measuring Instrument 2S Reliability Test GBll463", the reliability of the LED display is tested. In fact, it is difficult to achieve MTBF not less than 10,000. The reliability requirement of hours can not meet the requirement of high-reliability LED display. To make a high-quality LED display, the required supporting product materials must be greatly improved, and the development and design process must also include the use of heat, reasonable, and advanced technology.
1. R & D design ideas
1. Insist on using mature and standardized technology
Adopting mature and advanced technology in LED technology; designing to ensure that all devices deal with derating working conditions; adopting a reasonable operating model in terms of reliability: adopting complete standards in process; fully considering rationality in plan indicators, and not blindly pursuing nothing. High index of meaning; glowing
In the selection of components and driver chips, high-quality materials are used; the screen structure is modularized and standardized; in the selection of components and supporting equipment, high-quality brands are considered.
2. Introduce advanced technology
Using the most advanced high-definition video insertion and signal processing system to ensure high-fidelity video restoration.
Using single-point brightness correction technology, that is, by adjusting the current pulse width of each LED to control the pixel brightness, the brightness of the entire screen is uniform.
Single-point brightness chromaticity correction technology: make the LED display screen show the true colors of nature, and realize the true restoration of colors; make the error between the color coordinates of each pixel of the same color △X, y<0.003, and ensure that the LED The uniformity of the display color reproduction.
Eliminate brightness attenuation year by year: The maximum calibrated white balance brightness of the display screen should be greater than the brightness in actual use. The brightness is calibrated point by point by the manufacturer on a regular basis to ensure that the white balance brightness of the display screen after calibration during operation is not lower than the actual brightness required.
3. Reasonable
Adopt a reasonable operating model, increase parallel links, reduce series links, adopt hot standby technology and dual-channel self-healing structure. Due to the cost and process feasibility of the display screen, it is impossible to use parallel models for all operating models. Parallel model means that when the same units of a product are working at the same time, as long as one unit does not fail, the product will not fail.
2. Choose reliable supporting product materials
1. LED lights and chips.
LED lights are not only LED light-emitting tubes, but also the key components of LED electronic display screens. Therefore, reliable quality and mature LED products should be used in packaging. The selected LED products must have the following requirements:
Good stability and low dispersion.
High ESD index: HBM is greater than 4000V.
Small attenuation range: less than 5% for 1000 hours
Strong withstand voltage: Vr=10V, Ir<2uA
High consistency of brightness, wavelength and angle.
Good light distribution effect: perfect light distribution curve.
It can resist temperature differences, humidity and ultraviolet rays, and is suitable for outdoor environments.
2. Box body.
The whole is made of steel plate or aluminum, and the door structure is adopted. Pins are used at the top of the box and guide sleeves at the bottom to ensure precise positioning between the boxes. The overall protection of the cabinet conforms to the IP65 standard, and the structure should fully consider heat dissipation issues.
3. Switching power supply.
The display power supply adopts the certified famous brand switching power supply module. All switching power supplies have undergone strict testing, screening and aging. Ensure full compliance with international safety and quality certification requirements to meet the requirements of long-term stable and reliable operation of the display. Under rated working conditions. Ensure that the service life is greater than 10 years.
4. Connectors.
The connector is an important connecting device in the system. High-quality connector products should be used to ensure the thickness of the pure gold plating of the connector and maintain the best electrical connection performance. Ensure the good electrical connection performance of the system under high temperature and high humidity environment, so that the system can run stably and reliably for a long time.
5. Circuit board.
The circuit board is made of flame-retardant epoxy board, the design layout is reasonable, and the wiring is standardized to meet the requirements of electromagnetic compatibility and circuit stability. Processing factories should choose products produced by well-known manufacturers.
6. Driver chip IC devices.
The driving circuit adopts the constant current driving chip of the international famous brand. In a large temperature range, maintaining high-precision constant current output and high reliability can significantly improve the uniformity and reliability of the display. The main materials of the display system should pass CE, FCC, UL, CCC, ISO9000 and other certifications.
I believe that if we do what we said above, adhere to reliable supporting facilities materials and professional R&D and design technology, we will definitely be able to reduce the failure rate of the display and greatly improve the reliability and stability of the LED display.
