Interest in micro-LED as a display technology is rising, helped – at least in part – by interest from Sony (Cledis screens) and Apple (through its LuxVue acquisition). LEDinside, a division of TrendForce, has forecast that micro-LED technology will be adopted for wearables in 2018, and for smartphones in late 2020.
Higher brightness, contrast and energy efficiency, as well as lower response times, are all benefits of micro-LED compared to LCD, or even OLED. It can also be used to achieve a high pixel density and different form factors, such as flexible or transparent screens. “In sum,” said LEDinside analyst Philip Chang, “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.”
The most significant challenge facing micro-LED makers today is finding a balance between pixel density and volume. Sony and Apple have diverged their strategies here.
Apple focuses on high pixel density, but low pixel volume. The firm intends to use micro-LED technology in sharp, high-resolution displays. This means that Apple is focused on reducing the size of the LEDs, which also leads to lower production yields. This means that Apple’s approach is only viable for small displays, such as those used in wearables. To date, Apple is said to have developed a 6″ prototype display at its research facility in Taoyuan, Taiwan. It is also using the expertise gained from its LuxVue acquisition to build full colour micro-LED displays with a high pixel density.
“Based 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, on the other hand, is sacrificing density for volume, prioritising screen size over resolution. This is because its Cledis displays will be viewed from a distance. Raising the size and pixel volume means that the number of LEDs used will also increase, so more time will be spent on building the displays, as well. Sony’s solution is to lower pixel density by using larger LEDs, which have higher yield rates. The Cledis display, says LEDinside, ‘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.’ Mass-production is expected to begin next year.