Following LCD and AMOLED, micro-LED has emerged as the next-generation display technology that is expected to be deployed widely in various applications. Increasing interests from electronics giants Apple and Sony during the recent period have encouraged further investments in micro-LED and accelerated the timetable for its commercialization. The latest analysis from LEDinside, a division of TrendForce, forecasts that micro-LED displays for smart wearable devices will enter the mass production stage in 2018. The technology will become available for smartphones later in 2020.
“Compared with the existing technologies, micro-LED offers significant improvements in many areas, including brightness/contrast, energy efficiency and response time,” said LEDinside analyst Philip Chang. “It also satisfies the demand for higher pixel density (expressed as pixels per inch or PPI) and other product design requirements, such as flexible and transparent screens. In sum, micro-LED overcomes the limitations of both LCD and AMOLED, and the mass production of displays based on this technology is foreseeable in the near future despite many unresolved technical issues.”
Chang added: “Currently, the most significant technical hurdle that prevents the mass production of micro-LED displays is finding the best balance in the trade-off between pixel density and pixel volume. In this matter, Apple and Sony diverge in their strategies to commercialize the technology.”
Apple focuses on applications that require high PPI but low pixel volume
Apple intends to use micro-LED to create sharp, high definition displays. Therefore the priority is to reduce the size of LEDs used for each pixel. As LEDs become smaller, their production yield rates also drop. Hence, Apple’s approach is only cost effective and commercially feasible for small-size displays used in wearable devices. Currently, Apple has successfully developed a 6-inch prototype micro-LED display at its research facility in Taoyuan, Taiwan. Besides the continuing R&D efforts at the Taoyuan facility, Apple also takes advantage of the LuxVue acquisition and are working with strategic partners to develop full color micro-LED displays with high pixel density. Apple’s goal is to advance the technology beyond the display specs of Apple Watch devices that are currently on the market.
“Basing on the technology’s development level and Apple’s product roadmap, Apple is likely to launch wearable devices with micro-LED displays in 2018,” said Chang. “However, the market will have to wait much longer for Apple to use micro-LED in the iPhone series because smartphone screens require greater pixel volume.”
Sony sacrifices pixel density for greater pixel volume
Sony prioritize screen size before image quality as its micro-LED displays will be viewed from a distance. Since increase in size and pixel volume will also increase the number of LEDs used on the display, more time and effort will be spent on making the product as well. Sony’s solution is to lower the PPI (or to increase the pixel size) by using larger LEDs, which in turn have high production yield rates. Sony unveiled a costly micro-LED display solution known as Crystal LED Display in 2012. Since then, Sony has made adjustments in its development strategy as to speed up the commercialization of the technology. Earlier this year, Sony introduced its second-generation micro-LED display solution called Crystal LED Integrated Structure (CLEDIS™). CLEDIS overcomes the constraints related to LED’s cost and yield rate issues by allowing multiple micro-LED panels to connect together to form a large, continuous display. CLEDIS-based products are expected to enter the mass production phase in 2017 as scheduled.