Development of a Slim Light Field Head-Mounted Display for Natural and Comfortable 3D Viewing

NHK Science & Technology Research Laboratories (STRL) is developing a head-mounted display (HMD) based on the 'light field' method, aiming to achieve virtual reality (VR) experiences that look natural and minimize visual fatigue.

In this development, the lab combined a unique optical system featuring two different types of lenses placed in contact with each other and a high-definition micro-display. This has successfully achieved both significant slimming and higher definition compared to previous prototypes.

Conventional VR goggles create a sense of depth by showing parallax images to the left and right eyes, but since the focal point remains fixed on the display, 'visual fatigue' has been a challenge. The newly developed light field method reproduces the 'bundle of light rays' emitted from objects, allowing users to focus naturally as they do in the real world, thus enabling natural 3D images that are less tiring even during long viewing sessions.

Regarding the optical system, the lab addressed the previous challenge of needing space between the lens array and the eyepiece by devising a new optical system where they are placed in contact. By delivering 3D images directly to the eyes without an intermediate image, the depth of the optical system was reduced by 79% compared to conventional models. Furthermore, by using high-speed ray-tracing technology, the system displays high-definition 3D images in real time.

This technology will be exhibited at the 'Giken Open House 2026,' held from May 28 to 31. Looking ahead, the lab aims to further improve the technology for applications in education, medical care, and entertainment.