Browse Prior Art Database

View Restricting Apparatus for Terminals

IP.com Disclosure Number: IPCOM000041096D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cato, RT: AUTHOR

Abstract

This article describes two techniques for allowing a user of a terminal, particularly a portable personal computer, to limit visual access to information being displayed on the terminal screen. Both techniques provide "decoded" information to authorized viewers and garbled information to others.

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This is the abbreviated version, containing approximately 100% of the total text.

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View Restricting Apparatus for Terminals

This article describes two techniques for allowing a user of a terminal, particularly a portable personal computer, to limit visual access to information being displayed on the terminal screen. Both techniques provide "decoded" information to authorized viewers and garbled information to others.

The first technique requires that each authorized viewer have special eye glasses with liquid crystal shutters which can be rapidly opened and closed. The terminal would be programmed to present valid information during the "open" time periods and garbled information during the "closed" time periods. A viewer without the glasses sees what appears to be a continuously garbled display.

The second technique requires that each authorized user wear colored glasses, which serve as optical band pass filters. If the glasses are such as to pass two colors (e.g., red and blue), valid characters are alternately presented in the two colors on screens otherwise filled with garbled characters in randomly generated colors other than the passed colors.

As an alternative, the colored glasses can pass all colors except those in a narrow band. Valid data is presented in any color except the filtered color while garbled data is presented only in the filtered color. A viewer with the glasses will perceive valid data as characters that are slightly brighter than the remaining data.

Anonymous.

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