Browse Prior Art Database

Display System

IP.com Disclosure Number: IPCOM000090133D
Original Publication Date: 1969-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Lauwers, F: AUTHOR

Abstract

In this display system, each character is X-Y generated by a sequence of voltages representing segment extremities. Uniform tracing is obtained by a low-pass filter the useful characteristic of which looks linear if the above mentioned sequence provides a dilatation of real tracing element displacements. This goal is achieved by recording a table of fictive coordinates. For instance, if character A is to be traced on a CRT display, X and Y deflection devices can be provided with recorded analog voltage represented by sequence 1. However, in order to get a uniform line tracing, the beam trace is moved at constant speed by low-pass filtering of the mentioned sequential voltages. The filter characteristic is made to look linear if only a small portion of characteristic is used.

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Display System

In this display system, each character is X-Y generated by a sequence of voltages representing segment extremities. Uniform tracing is obtained by a low- pass filter the useful characteristic of which looks linear if the above mentioned sequence provides a dilatation of real tracing element displacements. This goal is achieved by recording a table of fictive coordinates. For instance, if character A is to be traced on a CRT display, X and Y deflection devices can be provided with recorded analog voltage represented by sequence 1. However, in order to get a uniform line tracing, the beam trace is moved at constant speed by low- pass filtering of the mentioned sequential voltages. The filter characteristic is made to look linear if only a small portion of characteristic is used. This is achieved by providing in fact the filter with a sequence 2 of X-Y coordinates instead of sequence 1 and representing fictive amplitudes of beam displacement used which are stopped at the correct position by an adequate clock. A table of coordinates similar to sequence 2 can be recorded by digital encoding for each character which is to be used.

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