Screen for slotted aperture mask color television picture tube

In a cathode ray tube including a faceplate and a shadow mask containing an array of vertically oriented slotted apertures for restricting electron beams directed therethrough to impinge upon and excite selected areas of phosphor material on said faceplate, a viewing screen comprising:

• a series of vertically oriented stripes of phosphor material extending across and coating the inside surface of said faceplate, the phosphor material of horizontally successive stripes differing in a repetitive pattern so as to emit different colors within each pattern when excited by electron beams, and
• a layer of light absorbing material coating the inside surface of said faceplate in the form of a matrix comprising vertical stripes of material interposed between the phosphor stripes and horizontal spans of material crossing said phosphor stripes,
• the vertical stripes and horizontal spans of light absorbing material defining the viewable portions of said phosphor stripes,
• the vertical dimension of said horizontal spans being less than or equal to the vertical region of each phosphor stripe between vertically adjacent beam landings not excited by said electron beams, such that a zero to positive vertical guardband is provided for each viewable portion,
• the horizontal dimension of the vertical stripes of light absorbing material being greater than the horizontal separation between horizontally adjacent phosphor stripes, such that a negative horizontal guardband is provided for each viewable portion.

In a cathode ray tube including a faceplace and a shadow mask containing an array of vertically oriented slotted apertures for restricting electron beams directed therethrough to land upon and excite selected areas of phosphor materials on said faceplate, a viewing screen comprising:

• a layer of light absorbing material coating the inside surface of said faceplate and comprising a web containing an array of vertically oriented slotted openings therein, there being a unique set of three horizontally spaced openings for each aperture of said shadow mask aligned to receive the electron beams passing through said aperture, and
• a layer of phosphor material coated on the inside surface of said faceplate within the boundaries of said openings, there being a different phosphor material for each of the openings of a set so as to emit a different color when excited by the electron beam impinging thereupon,
• the height of said web between vertically adjacent sets of openings being less than or equal to the vertical distance between vertically adjacent beam landings to provide a zero to positive vertical guardband for each phosphor area,
• the width of said web between horizontally adjacent openings being greater than the horizontal distance between horizontally adjacent beam landings to provide a negative horizontal guardband for each phosphor area.