RiTdisplay Corp.
In the past 10 years RiTdisplay Corp. has grown to be a world market leader for passive OLED displays. The spectrum of these products extends from monochrome to full colour OLEDs.
http://www.ritdisplay.com/index.php/en/

Raystar Optronics, Inc.
Raystar Optronics, Inc. specialises in the production of standard alphanumeric and graphic OLED displays as well as monochrome LC modules. In the last few years Raystar has succeeded in making a name in the Taiwan market as an OLED panel manufacturer.
http://www.raystar-optronics.com