Browse Prior Art Database

Display Panel Driver Interrupt Generator

IP.com Disclosure Number: IPCOM000084618D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 47K

Publishing Venue

IBM

Related People

Lucas, PM: AUTHOR [+2]

Abstract

In testing AC type gas panels it is necessary to determine the sustaining voltage maximum for the cells, so that with the voltage at that level no firing of the cells will occur, until orthogonally positioned and spaced apart electrodes are energized at their intersection.

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Display Panel Driver Interrupt Generator

In testing AC type gas panels it is necessary to determine the sustaining voltage maximum for the cells, so that with the voltage at that level no firing of the cells will occur, until orthogonally positioned and spaced apart electrodes are energized at their intersection.

Additionally, it is necessary to determine what the minimum sustained voltage is so that, in normal operation, none of the panel glow discharge intersections is extinguished when the memory of the gas panel is being sustained merely by the maintenance of the sustaining voltage. In order to test the entire panel for interrupt signals so that selected ones of the intersections will light or be extinguished, a simple interrupt test circuit is illustrated in Fig. 1 to operate on the panel and achieve the voltage line requirements or signal inputs to the panel illustrated in Fig. 2B.

Four logic signal lines on the gas panel driver must be interrupted for 77 mu sec +/- 8 mu sec at a predetermined time of 6 mu sec + 0.1 mu sec, after the horizontal signal rises to an uplevel.

During interruption, all logic lines must he held to a logical low level. After two full vertical pulses and the corresponding horizontal pulse the aforementioned occurs again. This cycle happens repetitively during the interrupt mode of operation.

Normal horizontal or vertical pulse widths are 16.7 mu sec +/- 1.7 mu sec. Five pulse widths total time equals 83.5 mu sec, nominal. The interrupt time of 77 mu sec + 8 mu sec plus the short horizontal pulse, just prior to the interrupt of 6 mu sec + 0.1 mu sec equals 83 mu sec + 8.1 mu sec. Therefore, five pulse widths of horizontal or vertical equals, well within the tolerance, the desired time for interrupt plus the preceding short horizontal pulse. In essence, a modification of the normal horizontal and vertical signals can be ...