Ultra-high frame rate digital light projector using chipscale LED-on-CMOS technology

Abstract

Digital light projector systems are crucial components in applications including computational imaging, fluorescence microscopy and highly parallel data communications. Here we present a chip-scale projector system based on emissive micro-LED pixels directly bonded to a smart pixel CMOS drive chip. Enabled by the high modulation bandwidth of the LED devices, the 128x128 pixel array can project binary patterns at up to 0.5 Mfps and toggle between two stored frames at MHz rates. The projector has a 5-bit grayscale resolution that can be updated at rates up to 83 kfps, and can be held in memory as a constant bias for the binary pattern projection. Finally, the projector can be operated in a pulsed mode, with individual pixels emitting pulses down to a few nanoseconds in duration. Again, this mode can be used in conjunction with the high-speed spatial pattern projection. The design of the smart pixels and LED devices are presented along with measurements of each mode of operation. As a demonstration of the data throughput achievable with this system we present an optical camera communications application, exhibiting data rates of >5 Gbps, over three orders of magnitude improvement on current demonstrations.