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Pincushion Correction for Penetration CRT Using Electromagnets

IP.com Disclosure Number: IPCOM000045056D
Original Publication Date: 1983-Jan-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Gorga, KJ: AUTHOR

Abstract

Voltage penetration screen color cathode ray tubes (CRTs), having a single electron gun, are well known in art. Such CRTs, since they have only one electron beam to direct, have no need for and, therefore, do not use either the alignment or convergence electronics that are necessary in conventional three-gun color systems. Typically, their screen receives a multiple layer phosphor coating that enables a cathode ray tube with a single electron gun to display information in up to four colors. The actual color that is displayed will depend upon the amplitude of the beam accelerating voltage employed. The overall quality of the display has a resolution comparable to that of a high quality mono-chrome tube employing conventional raster or scanning techniques.

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Pincushion Correction for Penetration CRT Using Electromagnets

Voltage penetration screen color cathode ray tubes (CRTs), having a single electron gun, are well known in art. Such CRTs, since they have only one electron beam to direct, have no need for and, therefore, do not use either the alignment or convergence electronics that are necessary in conventional three- gun color systems. Typically, their screen receives a multiple layer phosphor coating that enables a cathode ray tube with a single electron gun to display information in up to four colors. The actual color that is displayed will depend upon the amplitude of the beam accelerating voltage employed. The overall quality of the display has a resolution comparable to that of a high quality mono- chrome tube employing conventional raster or scanning techniques. The data is screen displayed by what has been variously termed random scan, x-y writing or stroke writing. As these names imply, the data is written to the screen by precisely deflecting the CRT beam to predefined locations and not, as in conventional monitors or displays, by sweeping the beam across the screen.

This type of CRT has proven useful, for example, in applications ranging from air traffic control and cockpit displays to industrial process control and public utility power dispatching. It has been found that the colors used in these displays, the phosphor composites of which are selected to eliminate blue, closely match the spectral respon...