A number of companies, including Apple, Valve, and LG, have invested in the OLED display manufacturer eMagin [roadtovr.com]:
According to documents filed last month with SEC, a new stock issuance of some $10 million by OLED microdisplay maker eMagin [emagin.com] will be bought up by Apple, Valve, and LG, among others.
Founded in 1993, Emagin is a producer of OLED microdisplays which have seen deployments in military, medical, industrial, and other sectors. With the rise of AR and VR in the consumer market, Emagin has recently marketed their display technology toward companies building consumer headsets.
The company's flagship product in this space is a 2,048 × 2,048 OLED microdisplay with a ~70% fill factor, which the company claims will eliminate the 'screen door effect' seen on today's consumer VR headsets.
[...] As for Valve, the company's chief, Gabe Newell, said back in 2017 that he expected VR display technology to make great strides in 2018 and 2019; a timeline which may have been guided by the company's involvement with Emagin:
"We're going to go from this weird position where VR right now is kind of low res, to being in a place where VR is higher res than just about anything else, with much higher refresh rates than you're going to see on either desktops or phones. You'll see the VR industry leapfrogging any other display technology. You'll start to see that happening in 2018 and 2019 when you'll be talking about incredibly high resolutions."
Also at CNET [cnet.com].