Abstract: An article of manufacture comprising a cathode ray tube is disclosed for use in a projection television system. The tube has a funnel and a face panel with a window for receiving a rectangular imaging screen. The projection television system includes tube receptacle means having conjugate means for accepting the tube in proper rotational alignment. The tube according to the invention is characterized by having two pairs of substantially radially oriented embossments on the funnel. The embossments are centered on, and azimuthally spaced one hundred and eighty degrees apart, on a diametrical line about forty-five degrees in counterclockwise rotation with respect to the minor axis of the rectangular imaging screen. The pairs of embossments according to the invention provide for engagement with the conjugate means of the tube receptacle means for proper rotational alignment of the tube in the system.

Abstract: This disclosure depicts a method of spot-knocking an electron gun having a heater and cathode, a control grid G1, a screen grid G2, and four main focus lens electrodes (G3, G4, G5, and G6), wherein a first relatively large gap exists between G2 and G3, between G3 and G4, between G4 and G5, and between G5 and G6, and a second relatively small gap exists between G1 and G2, and a third relatively very small gap exists between G1 and the cathode.

Abstract: Three substantially L-shaped bimetallic brackets accurately secured to the frame of a color television picture tube undergo corrective flexures in response to temperature variations. These flexures compensate for the thermal expansion of the shadow mask by maintaining the mask in proper alignment between the glass panel and the electron source over the operating temperature range of the picture tube.