eMagin Reveals Breakthrough with 10K Nit Micro OLED
Microdisplay maker eMagin announced last week achieving a major milestone in OLED displays that may enable the next wave of AR and VR devices. In a small event in New York City which I attended, eMagin demonstrated their full-color OLED microdisplay capable of 10,000 cd/m2.
As described in DSCC’s Annual Augmented and Virtual Reality Display Technologies and Market Report, displays are a key enabling technology for AR and VR, and may limit the ability of devices to deliver the immersive experience that they promise. Some of the early efforts at VR have been hindered by motion artifacts, low resolution or other issues. At the NY event, eMagin CEO Andrew Sculley gave a short presentation which included this comparison of some existing VR devices which do not achieve anything close to the resolution capability of the human eye.
Similarly, existing microdisplays often do not achieve sufficient brightness for VR. In order to avoid motion artifacts which can disorient the user, VR devices should operate at a low duty cycle with black frame insertion. According to Sculley, CE makers target a 10% duty cycle. With an optical system efficiency that is typically also in the range of 10%, a display brightness of 10,000 nits is required to deliver 100 nits to the eye.
The brightness of OLED microdisplays has been limited by the White OLED architecture used so far. It is based on an unpatterned OLED layer with color filters added on each subpixel to generate colors. The same principle is found in current OLED TVs, although with much larger pixels.
Since 2016, eMagin has been developing its Direct Patterning (dPd) technology to enable full-color OLED microdisplays at unprecedented combinations of brightness and resolution. Like the RGB OLED displays of smartphones, and unlike White OLED, eMagin’s OLED microdisplays employ individual red, green and blue OLED stacks at the sub-pixel level and do not require a color filter. Last year, eMagin achieved a brightness of 7,500 nits on a 0.9” display.
Another important aspect of eMagin’s dPd is the ability to achieve a high fill factor (fill factor = total emitting area of the three sub-pixels divided by total area of the pixel) with the high resolution. This can further reduce or eliminate the screen-door effect. Whereas OLED displays in smartphones typically have fill factors of only 20%, eMagin’s OLED microdisplay has close to 70% fill factor.
At the NY event eMagin demonstrated two new prototypes and one previously shown:
- A 0.87” full color WUXGA (1920x1200, 2645 PPI, 9.6μm pixel pitch) OLED microdisplay with >10,000 nits of brightness.
- A 2.1” 4K (3600x4000, 2613PPI, 9.72μm pixel pitch) full color OLED microdisplay. This was actually demonstrated to one of eMagin’s customers back in 2019.
- A previously demonstrated monochrome green 2.1” OLED microdisplay capable of 40,000 nits.
eMagin said that its displays could achieve 98% of DCI-P3, as published in a SID paper. The OLEDs use phosphorescent red and green and fluorescent blue emitters, and therefore the pixels are designed with larger blue sub-pixels to achieve good color balance. The microdisplays employ a single OLED stack, but eMagin said that their roadmap includes other advances such as tandem OLED that can be used to move beyond 10K nits. eMagin’s roadmap targets a full-color peak luminance of 30,000 nits.
eMagin 0.87” WUXGA OLED Microdisplay
Sculley indicated that eMagin is working with several consumer electronics companies to bring this technology to devices, but he could not name the companies. One company has signed a deal for licensing the dPd technology. Under that deal, the company was licensed to build OLED microdisplays for their own devices, but not for sale of displays. Another company plans to use eMagin’s 4K OLED microdisplay for its next VR device.
eMagin received a $39 million grant from the US government to enable small-scale production of microdisplays. While the company is currently using the dPd technology to process OLED microdisplays at full scale on 200 mm wafers, the technology is also compatible with 300 mm wafers. eMagin said that they are working with a tier-one consumer company to develop the dPd technology and manufacture at commercial scale.
eMagin CEO Andrew Sculley will describe his company and its technology in more detail at the AR/VR Display Forum this week, one of 21 presentations that cover the breadth of technology developments that will enable these exciting applications.