There is a scene in "The Terminator," the 1984 James Cameron movie, in which the audience sees through the robotic eyes of the title character, played by Arnold Schwarzenegger. When the superintendent of a building yells at the Terminator, a list of possible responses scrolls down the screen before he chooses one to shout back. The one he picks is a doozy.
Two decades ago, science fiction movies were the only place you could see a computer-generated image on top of a real-life background. By the end of 2001, a commercial product will achieve the same effect in real life by projecting images directly onto the viewer's retina, at the back of the eye.
Head-mounted displays are not new. Several companies, like Xybernaut ( news/quote ) and ComSonics, market L.C.D.-based displays for wearable computers. But projecting images directly onto the viewer's retina superimposes data on what is viewed without hampering the person's vision. Microvision Inc. ( news/quote ), based in Bothell, Wash., expects to market Nomad, a single- color version of that kind of display, by fall. In early April, the company delivered the prototype of a full- color retinal display called Spectrum to the Cleveland Clinic Foundation, a large private hospital.
On the surface, wearable scanning displays have more in common with bicycle helmets than with the computer monitors and televisions they may replace. The Nomad, for example, is mounted at the front of a molded plastic headpiece; its box of optical, electrical and mechanical components has a single window that can slide over either eye. The components are linked to a computer that can be worn on a belt.
The Microvision displays do not use a screen, although they work somewhat like a television set. Just as a cathode-ray tube in a television or monitor scans a beam of electrons onto the front face of the tube, the tiny projector inside a head-mounted display beams light through the pupil and onto the nerve cells in the retina.
At first glance, pointing a laser directly into your eyeball seems to fall somewhere between the risky and the downright foolhardy. But Microvision's retinal scanning devices comply with the safety rules set by the American National Standards Association and the International Electrotechnical Committee. According to Microvision representatives, the most recent standards for light levels allow beams that are almost 100 times as bright as those emitted by its retinal scanning displays.
Because the technology uses a scanning beam to paint the image on the retina, Microvision calls a device using this technology a retinal scanning display — not to be confused with the biometric technology of retinal scanning, which detects the distinctive pattern of blood vessels on the retina, a pattern that can be analyzed to identify someone, similar to the way fingerprints are used.
Although the display system is proprietary, it is based around open standards. It accepts television signals in the American NTSC and European PAL formats, as well as in the SVGA graphics format, which can display an image 800 pixels (or dots) wide by 600 pixels high. But while a head-mounted display could fit into a regular computer setup, the first series of applications for the product will take better advantage of its capabilities.
Microvision's first development partner for the prototype color display, called Spectrum, is the Cleveland Clinic Foundation. That hospital is focusing on clinical applications, like superimposing information about a patient, including vital signs and medical images, onto a surgeon's field of view. The single-color Nomad display could also be used for the controls of industrial machines and aviation, including air traffic control.
In industrial settings, for example, the Nomad display can give service technicians access to manuals. Drivers of heavy equipment will also be able to benefit from displays of maps and instrument readings as they keep their eyes on the road ahead.
A heads-up display can also be used in dangerous situations, giving firefighters in a smoke-filled building a floor plan, for example, or warning workers of gas leaks.
The first wave of applications for scanning displays will be geared for military, medical and aerospace users, in part because the cost is expectedto be around $10,000 for a single unit. But the devices may someday be marketed for consumers.
Eventually, it may be possible to relax on the couch to watch television with retinal scanning technology. So instead of experiencing James Cameron's dystopic vision of killer robots from a safe distance on a video screen, you could end up watching his movies through their eyes instead.
here is a scene in "The Terminator," the 1984 James Cameron movie, in which the audience sees through the robotic eyes of the title character, played by Arnold Schwarzenegger. When the superintendent of a building yells at the Terminator, a list of possible responses scrolls down the screen before he chooses one to shout back. The one he picks is a doozy.