Kathodenstrahlroehre zur bistabilen elektrischen Speicherung

摘要

1,070,530. Cathode ray storage tubes. TEKTRONIX Inc. Aug. 4, 1964 [Aug. 1, 1963], No. 31225/64. Heading H1D. A low-capacitance storage screen for a cathode-ray tube, having one or more flood guns and a further gun switchable for use for either reading or writing (Fig. 1, not shown), includes an insulating support coated on one side with a conductive material having a plurality of spaced apertures extending through the coating to the support, and secondary electron emissive dielectric contained within the apertures. The dielectric material 62, which may be a phosphor for direct viewing, is disposed on the tube faceplate 56, in the apertures of the mesh grid formed by intersecting lines of conductive material 32. The screen may be produced by coating the faceplate with aluminium, silver, or tin oxide, superimposing a coat of photosensitive material which is exposed to light transmitted through a film containing an image of the desired mesh, and developing and etching to remove the unexposed material and the underlying conductive coating. The photosensitive material above the mesh is then removed, and a photo-sensitive/dielectric mixture applied as a coating; this is exposed to light passed through the grid, the unexposed portions are washed off, and the plate is then heated to remove the photo-sensitive material from the dielectric. In a second method, the faceplate is coated with a photo-sensitive solution containing a powder-e.g. a silicate, phosphor, or metal oxide-which is insoluble therein; exposed to the light image of a mesh; developed and the unexposed regions washed off; coated with an evaporated conductive layer; the remaining photo-sensitive material and its overlying coating removed by the use of heat and abrasive; whereafter the last three stages of the previous process are applied. Some of the above steps may be dispensed with if the powder in the initial mixture is itself capable of forming an adherent conductive coating on the faceplate after heating. A further method employs a stripping type of photographic film. In a modified screen (Fig. 4, not shown), permitting the use of photoconductive dielectric material, the regions of the latter (621) are insulated from one another by glass ridges (68). This structure may be provided by etching through a masking coating of suitably exposed and developed photo-sensitive material, or by fusing on to the faceplate intersecting lines of glass frit.