Browse Prior Art Database

Pulse Scanning Graphic Image for Light Pen on Gas Panel

IP.com Disclosure Number: IPCOM000081352D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Criscimagna, TN: AUTHOR [+2]

Abstract

In the operation of a gaseous discharge display panel, a display is generated by selective ionization of gaseous discharge sites by application of appropriate coordinate drive signals to the selected sites to create the desired display. Once a site has been discharged, it is maintained by sustain signals, which are continuously applied to all sites during the normal panel sequence. For various applications, it is desirable to use a light pen associated with the display device to detect various display items and generate various functions based on the symbol detected.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Pulse Scanning Graphic Image for Light Pen on Gas Panel

In the operation of a gaseous discharge display panel, a display is generated by selective ionization of gaseous discharge sites by application of appropriate coordinate drive signals to the selected sites to create the desired display. Once a site has been discharged, it is maintained by sustain signals, which are continuously applied to all sites during the normal panel sequence. For various applications, it is desirable to use a light pen associated with the display device to detect various display items and generate various functions based on the symbol detected.

In a cathode-ray tube display, each image element is intensified in a raster scanning sequence and a light pen is actuated by a reintensity signal as it passes the field of the pen during the scanning sequence. However, in a gas panel, once an image is displayed, all picture elements are intensified simultaneously since the sustain signal is continuously applied to all display sites simultaneously, so that detection of specific discharge sites by reintensification is not possible.

One solution for modifying the intensity of a display on a gas panel to permit selective light pen detection operates as follows. In order to light pen detect a selected picture element, the computer or data source retransmits all the information to the display, but instead of writing the display a dot, or character vector at a time, it would instead send a command to super or high intensify. The command would cause the gas panel circuitry to develop a selected leading edge spike, instead of the selected light...