WUXGA OLED microdisplay promises lightweight and compact VR glasses

December 01, 2017 // By Julien Happich
As part of the EU’s LOMID project (Large OLED MicroDisplays) that Fraunhofer FEP is coordinating, the research centre has developed OLED microdisplays that significantly outperform others currently on the market.

One tangible result is the extended full HD (1920×1200 pixels) WUXGA OLED prototype, about one inch in diagonal, created by Fraunhofer FEP. The device is capable of operating at up to 120Hz for very fast refresh rates.

Two components make up the microdisplay: a silicon chip to control the pixels, and an OLED. The OLED consists of several organic layers monolithically integrated on silicon wafers. The microdisplay’s resolution and frame rate are set by the chip with the help of its integrated circuit.

“The trick isn’t just to raise the resolution and frame rate, but also to keep power consumption to a minimum at the same time,” explains Philipp Wartenberg, head of department at Fraunhofer FEP, Wartenberg.

“We’ve been very successful at that thanks to a cleverly designed system concept and modern design methodology, not to mention our more than ten years of experience at Fraunhofer FEP in designing OLED microdisplays.” 
Further prototypes are due to follow by the middle of 2018. Industry partners involved in the project have already indicated their interest in converting this microdisplay into a marketable product in the near future.

Although VR may be the largest market in the medium-term for such OLED microdisplays, the researchers anticipate that AR glasses or view finders in cameras could also benefit from the technology. The underlying technology of CMOS-integrated light emitters (and any detectors) may also find its way into other market segments such as optical metrology and identification, or optogenetics.

Applying OLED microdisplays to augmented reality glasses calls for a number of challenges to be solved, including the need for very high levels of luminance and efficiency (which will necessitate removing the colour filters used today, and replacing these with directly structured emitters).

But even more challenging may be to reach a high yield for a large chip area, with curved surfaces for more compact optics; creating circular light panels and irregular pixel matrices at even higher