Bidirectional OLED microdisplay: Combining display and image sensor functionality into a monolithic CMOS chip

This paper presents a bidirectional OLED microdisplay (BiMi) with a mono chrome 320x240 (QVGA) display and a nested image sensor with 160x120 pixels in a commercially available 0.35μm 3.3V/12V CMOS process with customized top metal. The BiMi was designed as a universal prototype for evaluating the necessary display parameters in see-through HMDs and the eye-tracking capabilities in a nested setup with relatively low resolution. Because of the varying ambient light levels in see-through applications the main target was to achieve a wide range of possible display luminances from 100 to 10000Cd/m
²
instead of high resolution.