Revolutionary AR Glasses Offer Lighter Design and Expanded Head Movement
An international team of researchers has developed augmented reality glasses that receive images from an external projector. This innovation addresses issues such as excessive weight and bulk. The work is being showcased at the IEEE VR conference in Saint-Malo, France, in March 2025.
Augmented reality (AR) technology overlays digital content on the real world via electronic displays. This approach gained popularity with gaming apps like Pokémon Go. It now finds applications in education, manufacturing, retail, and health care. However, wearable AR devices have not seen widespread use because of the heavy batteries and electronic components they require.
To solve these challenges, scientists from the University of Tokyo and their collaborators designed AR glasses that capture projected images instead of generating them internally. Their system relies on a beaming display method that eliminates the need for onboard power sources. This design keeps the glasses thin and light while maintaining high-quality visuals.
Earlier versions of light-receiving AR glasses were limited by the narrow angle at which they could capture light. Previous models allowed clear image reception only when the device was positioned within about five degrees of the light source. The new design overcomes this barrier by integrating a diffractive waveguide. Patterned grooves in the waveguide control the direction of incoming light.
The advancement increases the acceptable head orientation from roughly five degrees to approximately 20–30 degrees. This improvement enhances usability by allowing users to move their heads more freely without losing a clear image. The light-receiving mechanism is divided into two parts: screen optics and waveguide optics.
In the new system, projected light is first captured by a diffuser. The diffuser evenly directs the light toward a lens that focuses it onto the integrated waveguides. The diffractive waveguide then channels the light toward gratings positioned near the wearer’s eyes. These gratings extract the image light and deliver it to the user to create the AR display.
A prototype was built to test this technology. The researchers projected a 7-millimetre image onto the glasses from a distance of 1.5 meters using a laser-scanning projector. The projector was angled between zero and 40 degrees during testing. The inclusion of gratings as waveguides allowed the glasses to capture projected light at angles of around 20–30 degrees while keeping acceptable image quality.
The research team acknowledges that further testing and refinements are necessary. Future work will focus on improving wearability and integrating head-tracking capabilities. These enhancements will allow steerable projectors to adjust the beam according to the position of the glasses in a three-dimensional space. The team also plans to address current limitations such as ghost images, a limited field of view, monochromatic outputs, and the inability to accommodate prescription lenses.
