A virtual retinal display (VRD), also known as a retinal scan display (RSD) or retinal projector (RP), is a display technology that draws a

raster Raster may refer to: * Raster graphics, graphical techniques using arrays of pixel values * Raster graphics editor, a computer program * Raster scan, the pattern of image readout, transmission, storage, and reconstruction in television and compu ...

display (like a

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...

) directly onto the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

of the eye.

History

In the past similar systems have been made by projecting a defocused image directly in front of the user's eye on a small "screen", normally in the form of large glasses. The user focused their eyes on the background, where the screen appeared to be floating. The disadvantage of these systems was the limited area covered by the "screen", the high weight of the small televisions used to project the display, and the fact that the image would appear focused only if the user was focusing at a particular "depth". Limited brightness made them useful only in indoor settings as well. Only recently a number of developments have made a true VRD system practical. In particular the development of high-brightness

LED A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...

s have made the displays bright enough to be used during the day, and adaptive optics have allowed systems to dynamically correct for irregularities in the eye (although this is not always needed). The result is a high-resolution screenless display with excellent color gamut and brightness, far better than the best television technologies. The VRD was invented by Kazuo Yoshinaka of Nippon Electric Co. in 1986. Later work at the

University of Washington The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle a ...

in the Human Interface Technology Lab resulted in a similar system in 1991. Most of the research into VRDs to date has been in combination with various

virtual reality Virtual reality (VR) is a simulated experience that employs pose tracking and 3D near-eye displays to give the user an immersive feel of a virtual world. Applications of virtual reality include entertainment (particularly video games), educ ...

systems. In this role VRDs have the potential advantage of being much smaller than existing television-based systems. They share some of the same disadvantages however, requiring some sort of optics to send the image into the eye, typically similar to the sunglasses system used with previous technologies. It also can be used as part of a wearable computer system. A Washington-based startup,

MicroVision, Inc. MicroVision, Inc. is an American company that develops laser scanning technology for projection, 3D sensing, and image capture. MicroVision's display technology uses a micro-electrical mechanical systems (MEMS) scanning mirror with red, green, blu ...

, has sought to commercialize VRD. Founded in 1993, MicroVision's early development work was financed by US government defense contracts and resulted in the prototype head-mounted display called Nomad. In 2018,

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

announced Vaunt, a set of

smart glasses Smartglasses or smart glasses are eye or head-worn wearable computers that offer useful capabilities to the user. Many smartglasses include displays that add information alongside or to what the wearer sees. Alternatively, smartglasses are some ...

that are designed to appear like conventional glasses, which use retinal projection via a vertical-cavity surface-emitting laser and

holographic grating A holographic grating is a type of diffraction grating In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction ...

. Intel gave up on this project, and sold the technology to North. In the same year, QD Laser, a Japanese laser maker spun off from

Fujitsu is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...

, developed the first commercialized true VRD RETISSA Display. In the following year, the firm started to sell the successor VRD RETISSA Display II, which featured a higher resolution equivalent to 720p.

References

External links

Animations of how a VRD works
* {{DEFAULTSORT:Virtual Retinal Display Display technology Multimodal interaction Virtual reality Mixed reality Emerging technologies Japanese inventions

History

See also

References

External links