A flat display panel uses a DC gas-discharge and has flat discharge display elements, which elements have three electrodes composed of a cathode, a grid and an anode and a discharge stabilizing resistor. An auxiliary discharge is formed by using the discharge stabilizing resistor, the cathode and the grid in an auxiliary discharge space defined between the grid and the cathode. A main gas discharge is formed in a main discharge space defined between the anode and the grid by mainly using electrons in a plasma, produced in the auxiliary discharge space, which are diffused and accelerated into the main discharge space. The flat discharge panel, in order to provide a memory function in the main discharge is driven by the use of pulse voltage applied between the anode and the grid.

A writing head for reproducing a line on an image upon a light sensitive surface from a periodically pulsed signal, the timing or period of the pulses representing the position on the line at which writing is to take place. The writing head comprises a series of cathodes and two anodes in contact with a gas at low pressure. The two anodes are in the form of parallel, metallic adjacent strips extending transversely of the cathodes. One of the anodes is continuous and opaque while the other anode is formed with holes for allowing the light produced by gas discharge to fall on a photo-sensitive carrier. The cathodes may be disposed in a common plane and parallel to each other; they may also be connected in a cyclic array to a plurality of bus bars and successively energized.

The panel driven by the circuit of the invention comprises essentially two display devices in a single gas-filled envelope. The panel comprises a left-hand portion including an array of rows and columns of scanning or priming cells and an array of rows and columns of display cells which are vertically aligned with each other, with each scanning cell communicating with a display cell. Electrode arrays are provided for operating the left-hand scanning cells and display cells in scanning fashion, column-by-column. The right-hand portion of the panel includes an identical arrangement of scanning cells, display cells, and electrode arrays therefor. A panel of this type is particularly suitable for displaying 80 characters or so, and, in order to achieve favorable brightness in all of the cells of the panel, the two portions of the panel are operated simultaneously. The panel is operated by energizing the two sets of scanning cells sequentially, column-by-column, and, as the columns of scanning cells are energized, selected display anodes are energized by information signals to transfer glow from a scanning cell to the display cell above it.

A fluorescent display apparatus having a plurality of anodes linearly arranged and divided into consecutive several groups each containing the same number of anodes. Each of the anodes disposed in corresponding positions of the respective anode groups is electrically connected in parallel, and a control grid is provided in each of the anode groups in an opposed relation. A particular anode representing the value of an input signal is illuminated by energizing one of the anodes in the respective anode groups and one of the control grids.