Commercial VR glasses usually use displays from the smartphone market. These are available at low cost and allow a large field of view with simple optics. The disadvantage lies in the pixelized image representation due to the limited resolution and the insufficient pixel density. Modulating LCD and LCOS-based microdisplays are also used as an alternative. These are not luminescent, so external lighting is required. In order to make the VR glasses light and ergonomic, some manufacturers already rely on OLED microdisplays: These are based on organic light-emitting diodes that are integrated on a silicon chip and illuminate by themselves. They are therefore energy-efficient and offer very high contrast ratios of 10,000:1 and higher. In addition, the absence of backlighting allows simplified setup with fewer optical components. Another advantage of OLEDs is the high switching speed range of a few microseconds compared to milliseconds for LCDs. This enables high frame rates and the use of special modulation methods to improve the perceived image.
Researchers at the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP in Dresden, Germany, are working together with industrial partners in the EU project LOMID, in short for Large cost-effective OLED microdisplays and their applications, to develop novel OLED microdisplays with significantly better properties than commercial OLEDs. Our goal is to develop a new generation of OLED microdisplays that allow a compact design of the VR glasses and are characterized by excellent image quality,"explains Philipp Wartenberg, head of department at FEP, who is responsible for designing the integrated circuit in the silicon chip, OLED prototyping and overall project coordination in the project. But what is so special about the microdisplays that are being developed in the project? On the one hand, their resolution: They achieve extended full HD, their resolution is 1920 x 1200 pixels (WUXGA). The screen diagonals are one inch and the refresh rate is 120 Hertz. Movements are reproduced very fluidly. The microdisplay consists