The Japanese component maker TDK has unveiled what it calls the world’s first retinal projector built on a flat mirror for wearable eyewear. The meta-optic mirror measures just 150 nanometers thick and slips inside a standard lens, where a curved mirror would normally sit.

Conventional retinal projectors bounce laser light off a curved mirror in front of the eye, which forces bulky, conspicuous frames. TDK’s approach lays nanoscale reflectors on a plane and varies the reflection angle by position, so light arriving from many angles lands where it needs to. The payoff is transparency of roughly 80 percent in visible light, close to uncoated eyewear.

The design also keeps the image private. Because the picture is projected onto the wearer’s retina rather than scattered outward, people standing opposite cannot read the display, sidestepping a common complaint about heads-up optics.

Manufacturing is the other pitch. TDK says the mirror can be built with processes similar to semiconductor fabrication, a path toward cheaper mass production than the complex waveguides used today. The company already makes an ultra-compact full-color laser module and a laser controller it says can reach 4K.

The current mirror handles one color only. TDK aims to show full-color operation and reach volume production within the next few years, so this remains a lab milestone rather than a shipping part.

Source: Electronic Products & Technology