Teletransactions, Inc.

Teletransaction, Inc.

Jeffrey W Sutherland

Timothy P O'Hagan

A shelf tag comprising a liquid crystal display having optical states which are stable without power and an interface that allows for each character element to be programmed easily by sweeping a programming device across the character element contacts with all power and signal requirements being supplied to the shelf tag by the programming device. The programming device can be integrated with a portable transaction computer equipped with a bar code reader or can be embodied in a stand-alone apparatus capable of receiving user input, displaying information and interfacing to the shelf tags. A method of using the shelf tags, the programming device and a radio frequency computer local area network are presented which automates many typical business applications such as inventory updating and simultaneously changing prices advertised on the shelf tags.

Programmable shelf tag and method for changing and updating shelf tag

A front-lit, non-gray scale liquid crystal display device (10) including a polymer stabilized cholesteric liquid crystalline material has two optical states stable in the absence of an electric field. In a reflecting optical state incident illumination is directly reflected by the liquid crystal, producing a light pixel. In a scattering optical state incident illumination is absorbed by a black surface on the rear of the display, producing a dark pixel. A method employing a plurality of display control signals having the same polarity and differing phase relationships permits the fast video response of the display, notwithstanding that the average time to switch from a scattering optical state to a reflecting optical state is about 30 milliseconds, requiring about fifteen seconds to update a typical 480-row liquid crystal display using conventional array sequencing techniques. Several routines are presented for determining when to update such a display for a variety of applications.

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Akron, OH, United States of America

Jeffrey W Sutherland