| 摘要 |
1468697 Gas discharge panel store FUJITSU Ltd 2 Aug 1974 [3 Aug 1973] 34286/74 Heading G4C A gas discharge panel comprising row and column electrodes defining storage cells is readout by circuitry including charge storage unidirectionally-conducting devices connected to the row electrodes. The devices are charged immediately prior to a Read pulse applied to a selected column electrode so that, during a first part of the pulse, reverse current flows until the devices regain the ability to prevent reverse flow. The remainder of the read pulse causes a rise in potential on those row electrodes having a firing cell in common with the selected column electrode, so indicating the data stored. The Read circuit shown in Fig. 3 employs charge storage diodes CSD1-CSDn connected to the y electrodes of the discharge panel PDM. Prior to applying a read pulse to an x electrode, transistors QC and Q1-Qn are turned on for a period T to store charge in diodes CSD1-CSDn. As soon as these transistors are turned off a Read pulse is applied and QR is turned on. Initially a current Ic, Fig. 2, flows to charge the capactive load of all the display panel cells, this current flowing in the reverse direction through diodes CSD1-CSDn. The time T during which forward current flowed in the diodes is so chosen that they remain in the reverse conducting state until Ic ceases. The subsequent gas discharge current pulse Ig in those cells in the selected column that are firing can therefore not flow through the diodes CSD1-CSDn but instead flows into the stray capacitance at the inputs of amplifiers AMP1-AMPn, causing a rise in potential at the corresponding y electrodes which is passed to the outputs YR1-YRn by the amplifiers. This arrangement obviates the need for means to switch a reactor from low to high impedance between Ix and Ig as in a prior Read circuit (Fig. 1, not shown). |
