I was surprised to find there were no papers at the SID symposium on the AR/VR track that address the issue of the ultra-high brightness required for a see-through AR display to compete with high ambient light conditions. Most of the existing AR HMDs are designed for more modest light levels encountered this issue. The only paper in the symposium that addressed the issue directly was paper 79-4 from Sony, discussed elsewhere in this issue. Sony, instead of increasing the AR display brightness, decreased the ambient light by, essentially, putting electronic sunglasses on the see-through portion of the HMD wearer’s field of view.
(Source: SID 2018 paper 66-4)
MicroLEDs were a significant topic at SID but no micro-LED papers were on the AR/VR track. However, one paper on the MicroLED track caught my eye in particular. This was paper 66-4 titled “High Brightness Active Matrix Micro-LEDs with LTPS TFT Backplane.” This paper was written by Hyo-Min Kim and his 11 colleagues the represented a Korean consortium that included two groups at Kyung Hee University; the Korea Photonics Technology Institute (KOPTI); LEDLITEK Co. Ltd; Lumens Co., Ltd; and Sunchon National University. They reported producing a 40,000 cd/m² (nits) microdisplay with a resolution of 32 x 32 for a total of 1024 pixels. Of course, this is unacceptably low resolution for most AR applications and the chip was made in the lab, not a regular fab. Nevertheless, it shows that the future of see-through AR may be microLEDs. Not this year or next, however. (I think!) . –Matthew Brennesholtz
