Videos beamed straight onto human retina via compact laser projector

A compact device capable of projecting images and video directly onto the retina of a human eye has been developed by researchers from the University of Fukui.

 The Fukui team created the device by integrating a laser module capable of outputting red, green and blue lasers with a microelectromechanical (MEMS) mirror.

The direction in which the MEMS mirror reflects light from the laser module can be controlled electronically, making it possible to project high-quality 2D images through laser scanning over the projected area.

It can currently project colour video at a resolution of 1280×720, which, together with its small size, makes it a promising device for wearable displays.

The researchers said that further tuning will be required to make it possible to safely project images directly onto the retina of the human eyes.

One of the biggest challenges to getting the device working was combining the light beams from three independent laser sources to obtain an RGB output.

To achieve this, a device called a waveguide-type combiner was used, where each of the three waveguides receives light from each of the primary laser colours.

Akira Nakao, assistant professor and lead author of the study, said: “The outputs from the individual RGB lasers end up perfectly aligned thanks to the nature of the waveguide-type combiner.”

The researchers believe the applications for their device goes beyond those of virtual and augmented reality for entertainment and could allow for better conferencing, surveillance and even remote-assisted surgery.

“For now, our unit can be used in laser microscopes, sensors, projectors and HUD displays, particularly those for novel automobile systems with intelligent driving technology, which are all set to reshape our future,” Nakao said.

In October, Stanford University researchers developed a new architecture for OLED displays which could support resolutions up to 10,000 pixels per inch which would be perfect for improved VR headsets.