NEW YORK (AP) _ Sony Corp. has introduced to the U.S. market its Data Discman, a portable device that plays ''electronic books'' stored on cartridges that resemble miniature compact discs.

The Data Discman, about the size of a thick paperback, has been available in a slightly different version in Japan for about a year.

The Japanese electronics maker said Thursday the 2-pound device will be in U.S. stores starting in early November at a list price of $549.95. It will come bundled with three discs containing an electronic encyclopedia, a health reference guide and a translation guide aimed at travelers.

The Data Discman is based on the laser technology used in CD music players, but is designed primarily for text and graphics, displayed on a small, flip-up screen.

The Data Discman also can play minimusic discs, which hold only a few songs, through a set of headphones.

But sound cannot be mixed with the text. That means the discs cannot provide the capabilities of the new ''multimedia'' computer discs, in which snippets of speeches by famous people are provided along with encyclopedia articles, for example.

In addition, the graphics are crude compared to those on personal computers. A major reason is the Data Discman's liquid-crystal screen, which displays only black-and-white images in low resolution.

But Sony officials said the Data Discman is easier to use than a PC, is cheaper and is portable, so it should be attractive to many more users than computer-based devices.

Sony also says its device is more useful than the single-purpose handheld electronic gizmos that have been introduced in recent years, such as electronic Bibles and pocket translators.

Linda Helgerson, editor of CD Data Report, a newsletter that covers the CD industry, said Sony has yet to come up with compelling disc titles that would justify the high price of the Data Discman.

She also said she believes Sony eliminated much of the potential market by using a 3-inch minidisc instead of the standard 5-inch disc used in computers and CD music players. A 5-inch disc would have allowed computer users to take their data discs with them on the road.

The Data Discman is powered by either six AA batteries, a rechargable battery pack or a wall-outlet plug. A car cigarette lighter adapter will be an extra-cost option.

The device contains a tiny keyboard that allows users to search for a particular word or topic.

The Data Discman can be attached to a TV with a cord, provided to display the text and graphics in a much easier-to-view fashion.

The discs are housed in a protective case that resembles the one used for computer diskettes. The discs can hold up to 100,000 pages of text, or 32,000 graphic images.

Sony says 20 other discs will be available in November offering reference, travel and entertainment topics. They will be priced from $29.95 to $69.95.

Material for the discs is coming from book publishers such as Houghton Mifflin and reference book providers such as Official Airline Guides.

Sony officials told a news conference they also are exploring business and industrial discs, such as parts catalogs and product price lists.

Michael Vitelli, president of Sony Personal Audio Products Co., said Sony has licensed the Data Discman technology to other electronics makers, including Canon Inc. and Matsushita Electric Industrial Co., which are expected to make their own versions.

Vitelli said the intent is to establish the Sony technology as the standard for the devices, which should encourage companies to produce discs.

The Data Discman is just another in an array of consumer electronic gadgets based on laser-disc technology, including upcoming home entertainment and education devices that attach to TVs.

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