Browse Prior Art Database

Composite Computer Input/Output Device

IP.com Disclosure Number: IPCOM000038807D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Campagna, FJ: AUTHOR [+2]

Abstract

Described is an input/output device 10 based on a liquid crystal display (LCD) and a high resolution high-performance graphics tablet. The design incorporates a digitizer tablet into a liquid crystal display package so that one can input and output via a single device. The figure illustrates the structure of the disclosed device. The graphics tablet utilizes a technology called "resistive decoding". The tablet is available in a number of types of surfaces from transparent to opaque. The graphics tablet electronically senses the position of a stylus on its surface and reports this position to a computer in a digital form (format) it can understand.

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Composite Computer Input/Output Device

Described is an input/output device 10 based on a liquid crystal display (LCD) and a high resolution high-performance graphics tablet. The design incorporates a digitizer tablet into a liquid crystal display package so that one can input and output via a single device. The figure illustrates the structure of the disclosed device. The graphics tablet utilizes a technology called "resistive decoding". The tablet is available in a number of types of surfaces from transparent to opaque. The graphics tablet electronically senses the position of a stylus on its surface and reports this position to a computer in a digital form (format) it can understand. Data from an external source is displayed by an electronic stylus 12 which induces, by capacitive coupling, AC currents in resistive layer transparent ITO (indium tin oxide) conductors 14. This results in a signal voltage across the LCD conductors 14, 16 which corresponds to the written state. In this way, data is displayed. The LCD write- in process is thus characterized by the use of the stylus 12. The mechanism of the electrical information read-out function is resistive decoding technology (RDT). An electronic circuit (not shown) which senses the AC currents at the edges of conductors 14 converts these signals to digital information, and calculates the instantaneous (X,Y) position of the stylus. A signal processing circuit (not shown) and decoding algorithm provide readout and...