Japanese company develops “invisible” display: can be worn directly on the cornea

    According to the “Nihon Keizai Shimbun” reported on December 20, including contact lenses and high-speed optical control type, eye-worn display-related new technologies are emerging. Researchers are committed to solving a series of problems with wearable devices, such as lack of compactness and lightweight, and part of the population feels dizzy when watching. By upgrading virtual reality (VR) devices, they are actively exploring the optimal shape and picture quality of displays.

    Tokyo University of Agriculture and Technology professor Yasuhiro Takagi, together with Real Hitomi, has developed a miniature display that can be worn directly on the cornea of the eye. It is a transparent round object that can be placed on the fingertip, and after wearing it and focusing on the eyes and gazing carefully, more than 500 words of English will appear in front of the eyes.

    Microdisplay thickness of 0.15 millimeters to 0.25 millimeters, wearing methods and vision correction used in contact lenses are basically the same. It is equipped with a micro-semiconductor chip, through a dedicated wireless technology from smart phones and other devices to receive data and display it. Because it is powered wirelessly, this miniature display does not require batteries.

    The display can show not only text information but also images. It is envisioned that it can be used to display subtitles in the form of synchronized translation of sounds heard by the wearer, and to fuse map information with the actual scenery seen, among other things.

    The development of the basic technology for the display has been completed, and it is currently in the stage of advancing the development of the production technology. The person in charge said, “According to what we have investigated, this is the world's first technology.” The R&D team aims to realize productization in the future in cooperation with equipment manufacturers and others.

    Wearable displays in the form of eyeglasses and goggles are expected to become another important product after smartphones as network connectivity and artificial intelligence (AI) and other related functions are upgraded.

    The global market for the virtual space meta-universe is forecast to reach $507.8 billion by 2030, expanding to 11 times its 2022 level, according to Germany's Statista data platform. Augmented reality (AR) and VR smart glasses worn on the eyes are the main devices for virtual space, and the global market size for these devices will reach $51 billion by 2036, expanding to three times that of 2023, according to market research firm SDKI.

    However, there are many problems with the popular devices on the market today. Many of them are expensive, discouraging consumers. In addition, there are a series of criticized problems, such as large and heavy, limited battery drive time, rough picture quality, and vertigo sensation when worn by some people. Contact lens-based devices offer a radical solution, at least in terms of weight and power supply.

    At CEATEC 2024, an information technology exhibition held in October, Tokyo Electric Chemical Industry exhibited components for eyeglass-type terminals that control light up to 10 times faster than conventional technology. The use of lithium niobate realizes high-speed control and makes it possible to draw high-definition images of 4K or more. By controlling light with voltage rather than current, power consumption has been reduced to one-fourth of what it was before.

    Lightning Silicon Valley Technologies is a U.S.-based startup that is actively promoting technological development centered on technicians who used to work at Olympus Optoelectronics, in an effort to make possible wide field-of-view, high-brightness, and high-definition drawing technology for use in VR terminals.

    Due to individual differences, some people experience discomfort when wearing VR equipment. Researchers have yet to fully identify the cause of “VR vertigo”. Toshiyuki Ogura, who has been involved in the development of TV sets at Sony for about 40 years, said that the cause of vertigo in some people wearing VR equipment “may be related to the gap between the picture and reality. According to his analysis, there are subtle differences between the images displayed in virtual space and real landscapes in terms of three-dimensionality and color, which may cause confusion in the brain. Improving the clarity of the display may help improve the experience.