Seoul National University's College of Engineering to Significantly Reduce VR Display Size
3.3mm VR optical system developed... Commercialization possible within two years
Application of 2D lens array and optical path folding technique


Until now, virtual reality (VR) devices have been implemented in the form of head-mounted displays (HMDs), which have been uncomfortable to wear, which has been an obstacle to the spread of VR.

Seoul National University's College of Engineering announced on the 29th that a research team led by Professor Lee Byeong-ho of the Department of Electrical and Information Engineering has developed a new VR display technology that can significantly reduce the size of VR devices.

Existing VR displays are bulky due to the space they occupy. Reducing the thickness of this space requires shortening the focal length of the VR optical lenses. However, due to the minimum distance required between the eye and the lens, lenses with too short a focal length cannot be used.

The lens array VR display proposed by the research team this time has a structure that inserts a two-dimensional lens array in addition to the existing lenses. The structure has small lenses arranged in parallel, which reduces the actual focal length of the lens, reducing the required space to less than half of the conventional one.

The research team also applied a folding technique to fold the optical path so that light travels back and forth within the optical system. This further reduced the required space by one-third, reducing the total volume to less than one-sixth. Consequently, the team successfully developed a VR optical system design that theoretically requires only a 3.3mm-thick space.

The newly developed VR display optical system is not only thin but also has a wide field of view (102° horizontal, 102° vertical), an 8.8mm wide eye-center location area (Eye-Box), and a 20mm focal length, making it suitable for glasses-type VR displays.

The research team unveiled a prototype glasses made using an LCD panel and a Fresnel lens. This glasses-type device is only 8.8mm thick, including the thickness of all necessary components such as the internal space, LCD panel, and Fresnel lens.

Professor Lee Byeong-ho said, “The technology has been applied for an international patent,” and “If there is a company that is willing to produce the product, it can be commercialized within one to two years.”

Meanwhile, the results of this study were published in the academic journal 'IEEE TVCG (Transactions on Visualization and Computer Graphics)' on March 25.