GB1442804A - Cathode ray tubes and their manufacture - Google Patents

Abstract

1442804 Cathode-ray tubes SINCLAIR RADIONICS Ltd 4 March 1974 [2 March 1973] 10247/73 Heading H1D In a cathode-ray tube suitable for production in a miniature size, the envelope includes two portions joined together along a seam, and all the electrodes of the tube are positioned and supported by their lead-in wires which pass through the seam. As shown, a display tube has an end cap 12 provided with a phosphor screen 13, the remainder of the envelope being formed by the two halves 10 and 11, the three parts being joined by soldering with a low melting point glass frit, through the resultant seam between parts 10 and 11 of which pass the support and lead-in conductors 22, 25 and 26, 28, 32 and 33, 36, 39, 42, 46 and 47 for, respectively, the screen potential control electrode 20, Fig. 5 (and Figs. 9 and 10, not shown), the X deflection plates 23 and 24 (and Figs. 11 and 12, not shown), an apertured screen plate 27 (and Figs. 13 and 14, not shown) disposed between the X deflection plates and the Y deflection plates 30 and 31 (and Figs. 15 and 16, not shown), and third, second, and first gun anodes (34 and 37, Fig. 4, not shown) and 40, Fig. 5 (and Figs. 17 to 22, not shown), a grid electrode (43, Fig. 4, 23, and 24, not shown), and directly heated cathode filament (44, Fig. 25, not shown). The screen plate 27 may be connected to the third gun anode by side plate 27a, and the grid electrode (43) and cathode filament (44) are permanently assembled together by fused glass beads (53). In manufacture of the tube, all the electrodes are temporarily secured together, while mounted in a jig with the correct spacing and orientation, by securing the various support wires to a glass rod frame (123, Fig. 48, not shown) with adhesive; the frame is then mounted in a jig with envelope parts 10, 11 and 12 in a furnace, and heated to seal the parts together and to the lead-in and support wires, for which grooves may be provided in the facing surfaces of the envelope parts. An evacuation tube may simultaneously be sealed to an orifice in the envelope, and thereafter employed to evacuate the tube before it is itself sealed off.