Variable Clock and EM Signal Generation Scheme for Foveation-Based Driving OLED Head-Mounted Displays

An image processing pipeline and multi-output shift register of a foveation-based driving scheme are proposed for the realization of immersive head-mounted displays in 2019. In addition, this paper describes a variable clock generation circuit to manipulate output waveforms of shift registers in the foveated display. The EM circuit for OLED displays is also introduced to support the control signal to keep OLEDs of pixels from emitting light during the compensation. Especially, the EM circuit consists of only four TFTs and one capacitor and gives rise to pulses of variable widths corresponding to the resolution of a driven display area. A variable clock generation scheme is verified with 60 Hz 1440 x 2560 monitor, eye-tracker, PSoC board and FPGA board. An EM circuit is simulated by SPICE for 9600 lines and 120 Hz foveated displays.