JBD a leading MicroLED display manufacturer, has announced the development of its single chip native color monolithic polychrome (RGB) MicroLED displays, developed for augmented reality (AR) glasses applications. The display has a 5 µm color pixel pitch and a corresponding 2.5 µm monochrome R, G & B sub-pixel pitch. The display size is 0.22” diagonal with a qHD resolution of 960 x 540 pixels. The company is currently mass producing its flagship 0.13” 4 µm pixel pitch monochrome Red, Green and Blue displays and will be ramping up capacity at its new Hefei plant, with an annual production capacity of 120 million microLED displays. This is a new product family aimed at next generation AR glasses with even smaller form factor and ease of system level integration.
Fig. 1. 0.22” Monolithic full color MicroLED panel and inset shows a conceptual monolithic polychrome projector with a waveguide
MicroLEDs is the front-runner micro-display technology for AR glasses, as it offers the highest efficiency, brightness, contrast ratio, longest device lifetime, ultra-fine pixel density and ultra-compact form factor over incumbent micro-OLED, LCoS and DLP technologies. To build a high resolution (< 5 µm pitch) full color microLED display, existing technology would require the integration of three separate monochrome R, G and B display panels, usually combined with an X-cube as demonstrated by JBD's VGA polychrome projector. Whilst a single panel RGB solution is ultimately desired to maintain smallest light engine footprint, the advent of such technology remains elusive, as pick and place technology used for large TVs is not suited for ultra-fine pitch displays. Other approaches such as color conversion using quantum dots typically results in low efficiency due to re-absorption losses and device lifetime issues associated with high flux densities required for AR applications. Native color RGB grown by selective area epitaxy have also been proposed, although a convincing prototype at ≤ 5 µm pixel pitch has yet to demonstrated.
JBD is able to circumvent the technical challenges of a monolithic polychrome panel using its proprietary epitaxy and chip integration technology. Utilizing its expertise in monochrome panel architecture design, ultra-thin InGaN and AlInGaP epitaxy are integrated together and fabricated using conventional III-V thin-film processes. High wall plug efficiency sub-pixels is achieved using its patented engineered epitaxy layers which is less susceptible to edge effects with reducing pixel size, in addition to effective mesa sidewall passivation and microlens array to provide directional beam shaping. As a result of the current developments, JBD will demonstrate a breakthrough native color monolithic polychrome microLED micro-display with 5 µm pixel pitch. JBD will also showcase prototypes of its native color monolithic polychrome projectors at various industry events in Q1 2023.
JBD founder and CEO Qiming Li said: "This product is a new milestone for the company. We believe that only native colors can meet the brightness and reliability demands of a monolithic RGB display for AR glasses, and our technology will pave way for the Metaverse. We welcome potential new partners to design-in the monolithic full color projector into their next generation glasses”. Prototypes are expected to be shipped early next year with a 3 µm color pixel pitch version to follow after that.