US 5,389,855 A · Multi-beam electron gun for monochrome CRT

Abstract

A multi-beam electron gun for use in a monochrome cathode ray tube (CRT) such as used in a black and white television receiver, a projection television receiver, or a computer monitor includes G1 control and G2 screen grids each having a plurality of vertically aligned apertures for forming electron beams which are deflected in unison across the CRT's display screen to simultaneously trace a plurality of vertically spaced, horizontal scan lines with each display screen sweep. The electron beams are deflected across the screen in a raster-like manner with each beam containing video information for each adjacent scan line. The G1 control grid includes a plurality of discrete conductive portions each including a respective beam passing aperture and each coupled to a respective video signal source, with the video signal sources including memory for storing video signal information for subsequent display. This permits plural adjacent scanning electron beams to simultaneously provide adjacent portions of the same frame of a video image on the display screen. The grids in the main lens portion of the electron gun include vertically elongated, common apertures for focusing each of the electron beams on the display screen, with the electron beams deflected by a vertically oriented, self-convergent magnetic deflection yoke. In another embodiment, each of a plurality of vertically aligned apertures in the G1 grid has an associated cathode, with a respective video signal provided to each of the cathodes for simultaneously writing video information on adjacent horizontal scan lines on the video display.

Claims36

Dependent claims

An electron gun for a monochrome cathode ray tube (CRT) including a display screen whereon a video image is formed by sweeping an incident electron beam generally horizontally over a plurality of successive vertically spaced, horizontal scan lines in a raster-like manner, said electron gun comprising:

cathode means for providing energetic electrons;
a beam forming region (BFR) disposed adjacent to said cathode means and including first and second charged grids respectively having first and second arrays of spaced apertures for forming said energetic electrons into a plurality of beams, wherein each of said first and second arrays of apertures are aligned generally vertically and wherein each aperture of said first array is aligned with a respective aperture in said second array so as to form the energetic electrons into a plurality of spaced, generally vertically aligned electron beams;
and
lens means disposed intermediate said BFR and the CRT's display screen for receiving said vertically aligned, spaced electron beams and focusing the electron beams as vertically aligned, spaced spots on the display screen, wherein each electron beam is simultaneously swept over a respective scan line in forming a video image on the. display screen, and wherein said lens means includes third and fourth charged grids respectively including first and second vertically elongated apertures for passing and focusing the electron beams on the display screen.

1 more element

Dependencies are inferred from the claim text.

Multi-beam electron gun for monochrome CRT

Life of this patent

Multi-beam electron gun for monochrome CRT

Life of this patent

Abstract

Claims36