| 摘要 |
1,130,206. Colour television tubes. RADIO CORP. OF AMERICA. 29 Oct., 1965 [5 Nov., 1964], No. 45996/65. Heading H1D. In manufacture of a rectangular, shadowmask, colour cathode-ray tube, the phosphor dots of the mosaic screen are laid down in an array having an axially asymmetrical distortion relative to the aperture array in the shadow mask, to compensate for asymmetrical faceplate collapse consequent upon tube evacuation, and/or for non-coincidence of the horizontal and vertical electron beam deflection centres. The screen may be produced by exposing each colour phosphor in turn with an associated photo-sensitized gel, through the shadow mask, to light from a point source passing through a refractive lens 37 having different cross-sections 40, 42 along perpendicular axes 41, 43 parallel to the major and minor axes of the rectangular screen. The lens 37 may also provide an axially symmetrical correction compensating for general axial movement of the deflection centres, or a plurality of lens may be used in series to obtain the desired effect. |
