Mitsubishi Crafts Tiny LCD

Try on a wearable display--those in-front-of-the-eyes video displays that some futurists believe we will all be using in a few years--and you'll soon face one of two problems: Either the display is fixed in front of your eyes, making it impossible to look at anything else, or with those designed to permit a wider field of vision, it constantly flickers away in the corner of your eyes while you try to concentrate on something else.

Now, engineers at Mitsubishi Electric have developed a new type of display that should make using and living with head-mounted displays easier. The new display is mounted on a boom designed to be placed just below one eye and to disappear from view when you look away from it. The company has managed this by playing around with the LCD panel and optics of the unit.

Almost all LCD panels have a light in contact with the screen, either in front of it (a frontlight) or behind it (a backlight). In a wearable display, this means the light from the LCD panel is diffused across a large area of the eye and thus some of the light from the panel is visible even when you look away.

The Mitsubishi Electric engineers got around this problem by moving the light about 1 inch away from the display panel so that the image is more tightly focused on a small area of the eye. Look down to view the image and you can see it, just as normal. However, look up from the display to see something in front of you, and the image is now hitting a part of the eye away from the pupil, so it becomes invisible. More precisely, a movement of more than a hundredth of an inch in the vertical plane or a tenth of an inch in the horizontal plane puts the display out of view.

Varied Uses

The new headset and details about its operation were announced at the company's research and development center in Amagasaki, in western Japan. Development is scheduled to be complete by the end of March, said Yukio Sato, group manager of Mitsubishi Electric's laser and optics technology department. By April, the company will work on putting the finishing touches to a development model that will be offered to companies for evaluation.

"We're really keen to see how people will use such a headset," said Sato.

The company already has some ideas: Parents could use it to keep an eye on children while doing something else, and emergency service workers could check data as they carry out their duties.

The display unit measures 2.8 by 1.1 by 0.72 inches and weighs less than an ounce.