GB1173989A - Improvements in or relating to Electron Image Storage and Display Devices - Google Patents

Abstract

1,173,989. Cathode-ray storage and display tubes. TEKTRONIX Inc. 28 Nov., 1967 [28 Nov., 1966], No. 54059/67. Heading H1D. In a direct-viewing bi-stable storage tube, the target structure comprises a "mesa'' arrangement of phosphor dots 24 capable of both bistable storage and display and an intervening phosphor matrix 20 capable of high brightness display, but with non-storage characteristics. The phosphor 20 is deposited in matrix cavities 18 from a suspension, the cavities having been etched in the glass faceplate 12 following a photographic resist pattern-forming process. A metal layer 22, e.g. of aluminium or gold, is deposited over the phosphor matrix 20 to act both as a light-reflector for the phosphor matrix 20 and as a collector electrode for secondary electrons emitted by the phosphor storage dots 24. The metal layer 22 may also serve as a signal electrode. Light from the phosphor storage dots 24 is transmitted through the glass mesa portions 26 of the faceplate 12. In manufacture of the target structure a lacquer layer is applied to the phosphor matrix 20 before deposition of the metal layer 22. A second lacquer layer is then provided over the metal layer 22 and the phosphor storage dots 24 formed in a photographic resist process in which the resist is exposed to light through the glass mesas 26. In this step the metal layer 22 isolates the phosphor matrix 20 from contaminating photosensitive material employed in the formation of the phosphor storage dots 24. Finally the structure is heated to remove the lacquer layers. The target structure is attached to a ceramic tube funnel 14 through a glass frit seal 16 and electrical connection is made between a conductive tin oxide film 28 beneath the glass frit seal and the metal layer 22 by an aluminium layer 30. In a modification of the target structure, Fig. 4 (not shown), a transparent conductive coating of tin oxide is provided on the etched surface of the glass faceplate 12 beneath the phosphor storage dots 24 and the phosphor matrix 20 and such coating may also extend through the glass frit seal 16.