Tokyo — A pocket television no bigger than a wallet will be on the market by 1983. Two major Japanese electronics companies, Hitachi and Toshiba, have already produced a test model doing away with the bulky cathode ray tube that until now has stood in the way of real miniaturization. Another company, Matsushita (which makes the Panasonic brand), is moving in the same direction.
The breakthrough has been achieved by using liquid crystals similar to those already familiar in digital wristwatches and pocket calculators.
The Japanese say color television is feasible, but for the moment they are sticking with black and white to make sure there are no basic flaws.
Both Hitachi and Toshiba expect to be on the local market in 18 months with a model selling initially at around $400.
As with most new products, however, the cost is expected to come down pretty sharply as the companies gain more experience, and demand increases.
Miniature television is seen as the logical next step now that the market for standard sizes has reached saturation. More then 99 percent of all Japanese households have at least one set, almost invariably color. Now the industry wants to push a trend toward one set per person.
The smallest set currently on the market is one produced by Sony that takes advantage of the development of a miniature cathode ray tube and semiconductor (integrated circuits) technology.
But this color model is still about 4 1/2 inches in width and height, about 11 1/2 inches deep, and weighs about 6 1/2 lbs.
And as long as the cathode ray tube remained indispensable, no further slimming could be done.
Both Hitachi and Toshiba, however, have adapted available liquid crystals to produce a flat television about the size of the tiny transistor radios now being held to millions of teen-aged ears around the world. The toshiba model weighs less than 10 ounces and the Hitachi version about a pound.
Although the screen in both is only an inch square, the two companies insist the image will be very clear.
The liquid crystals used are far removed from those now operating in desktop calculators. For television, there were additional requirements of an ability to withstand hours of direct-flow voltage, high-speed response, sharp black and white contrast, and display of intermediate color tones.
In the Toshiba set, an integrated circuit embedded with 52,800 image elements , condensors, and switch elements are mounted on a small silicon board. The crystal liquid panel laid on top reacts sensitively to electric signals emitted by the image elements.
Power consumption is low: only 1.3 watts for Hitachi, and 2.2 watts for Toshiba.
Unlike cathode ray tubes, these tiny television sets won't emit light. Instead they use exterior light, so the best viewing, in fact, could be at the beach.
Is there any need for such a small set?One engineer says: "Well, you could say it's a bit of a gimmick. But look at the immense popularity now of musical electronic calculators -- people are just intrigued by offbeat gadgets.
"It has practical uses. We see it being popular with the highly mobile young generation. Then again, imagine being able to watch your favorite daytime programs at the office without the boss noticing -- you couldn't do that with the present portable models on the desktop.
"Or, imagine you're at a World Series game.
"Someone hits a home run, but the moment that bat and ball connect, everyone leaps up in front of you, blocking the entire view.
"No problem. . . . You reach quickly into your coat pocket, switch on, and have a perfect action replay in your hand."