Demystifying The Black Technology In BOE's Flexible Display

- Sep 11, 2020-

On September 10, 2020, the 2019 Beijing Science and Technology Award was announced. BOE's "High-resolution flexible and flexible AMOLED display technology development and industrialization for mobile applications" project (hereinafter referred to as "flexible and flexible AMOLED project") It stood out in the review of many projects in 2019 and won the special prize of Beijing Municipal Science and Technology Progress Award.

   It is reported that the "Beijing Municipal Science and Technology Award Measures" set up a special prize for the first time, awarding special awards for making particularly significant scientific discoveries, breakthroughs in key core technologies, and generating particularly significant economic and social benefits or ecological and environmental benefits. BOE is the first and only company in this award to receive this honor.

  

It has always been people’s dream to fold the screen of a mobile phone. The BOE project team made it truly practical and achieved mass production of a 5 mm outward-folding mobile phone for the first time in the world, reflecting BOE’s technological innovation strength and enabling my country’s display technology to surpass the world. . This technology breaks through technical difficulties such as bending resistance, high-resolution design, long life, narrow bezel, and multi-process integration, reflecting unique design and independent innovation.

 


  BOE flexible roll-up display

   What are the "black technologies" of BOE's flexible display technology.

  1. Mass production of the world's first R5 outward-folding flexible display

  The radius of curvature and the bending life are two important indicators to measure the bending resistance of the flexible display screen. "R" refers to the radius of curvature of the flexible screen; and "R5 200,000 bends" means that the flexible screen can be bent 200,000 times without damage under the condition of a radius of curvature of 5mm. This bending life is flexible The screen is a necessary condition for commercial mass production and application to flexible folding mobile phones.

  Before the BOE R5 200,000-fold bending flexible screen was mass-produced, a common problem faced by the global display industry was how to solve the contradiction between the smaller radius of curvature, the screen thickness and the bending life. Previously, in order to correspond to a smaller radius of curvature, a common practice in the industry was to adopt a thinner device design. However, due to factors such as material development, excessive pursuit of thinness will reduce the mechanical and optical performance of the device.

  So, how can users experience a greater degree of flexible bending performance without affecting the bending life of the flexible screen?

Through a large number of simulation experiments, BOE is the first in the industry to propose a multi-neutral layer design theory, breaking the limitation that only a thinner integrated structure can achieve small-radius folding, and successfully designed a unique multi-film for outward-folding flexible AMOLED screens. Layer stacking structure and establishment of folding test evaluation standards, achieving 200,000 bends under the condition of a radius of curvature of 5mm, meeting user standards, and achieving mass production of 5 mm outward-folding mobile phones for the first time in the world

Based on the above technological innovations, the bending performance of BOE's flexible display products has continued to improve. In November 2018, in the CCTV "Come on! To the Future" program, BOE flexible display screens participated in popular science experiments, produced by the 0.1mm of the 6th generation flexible line of BOE Chengdu The 5.99-inch flexible screen with a thickness of 5.99 inches has withstood the manual bending of the reel with a radius of 1mm by the experimenter. Poke video

  2, independent pixel arrangement supports high-resolution design

   The higher the screen resolution, the better the display effect, so our end users prefer high-resolution displays.

BOE’s flexible display R&D team found through optical color matching analysis that the human eye’s ability to distinguish between brightness and different color graphics (edges, shapes) is different, of which brightness (light and dark contrast) graphics have the highest resolution, followed by red graphics. The blue figure is the lowest.

Based on this discovery, the scientists of the project team creatively invented a new high-resolution sub-pixel arrangement method and shared sub-pixel rendering (SPR) algorithm with BOE's independent intellectual property rights, which increased the aperture ratio by 20%; broke through the fine metal mask Plate (FMM) production and process bottlenecks have realized high-resolution pixel design.

In practical applications, for a high-resolution flexible screen with this pixel structure, the display effect is closer to true red, green and blue pixels, and the display color is more realistic; the aperture ratio of the screen can be increased by 20%, which means that the user is setting the same screen brightness Under the circumstances, the service life of the flexible display screen will increase accordingly.

   Based on the above technological innovation breakthroughs, BOE has deployed fully flexible sixth-generation AMOLED production lines in Chengdu, Mianyang and Chongqing. Among them, BOE Chengdu's sixth-generation flexible line has been mass-produced in October 2017, and Mianyang's sixth-generation flexible line has also been mass-produced in July 2019. The mass production of BOE’s two fully flexible sixth-generation lines has consolidated and enhanced the global technological competitiveness and market position of China’s new display industry, achieved technological transcendence, and freed my country from the current situation of over-reliance on imports for flexible displays, and guaranteed domestic intelligence Supply chain security for mobile phones.

  Qunzhi Consulting data shows that in the first half of 2020, BOE flexible AMOLED display shipments accounted for 20.3% of global shipments. Motorola, LG, OPPO, and Nubia have adopted BOE flexible screens.

At present, in addition to the mobile phone field, BOE is also applying flexible display products to smart cockpits, business offices, smart homes and many other fields, and continues to expand the application space of flexible OLED technology, unleashing unlimited potential for smart display terminal innovation, and bringing people's smart life. Come to a new experience.