Zenith Radio Corporation

Zenith Electronics Corporation

William A Rowe

Paul Strauss

James W Schwartz

A localized grinder is traversed in series over flat tension mask support rails affixed to a CRT front panel to produce a constant 'Q'-height on the mask support surface above the rails. A local measuring device is used to develop point-specific rail height information relative to the screen edges for operation of the grinder in order to ascertain an effective 'Q'-height measurement from the panel surface.

Rail following 'Q'-height grinder

A color cathode ray tube includes a faceplate having a predetermined pattern of phosphor deposits on a target surface thereof and a rear envelope section. A color selection electrode assembly includes a frame supporting in tension a foil having a pattern of apertures related to the predetermined pattern of phosphor deposits. Means are provided for bonding the color selection electrode assembly between the faceplate and the rear envelope section with the pattern of foil apertures in registration with said pattern of phosphor deposits such that the color selection electrode assembly is incorporated as an integral part of the cathode ray tube envelope. The foil is sized and the frame adapted such that the foil is supported completely within the tube enclosure on a peripheral frame surface facing away from the said faceplate.

Tension mask color cathode ray tube apparatus

A projection optical system is disclosed that is protractible and retractible within a narrow spatial column for emerging from and nesting in a cabinet of an ultra-compact, rear-projection television receiver. The system comprises in combination a stationary optical assembly permanently enclosed in a lower portion of the cabinet and having image projection means and first mirror means. A protractible optical assembly is elevatable as a unit from the cabinet; the assembly includes a mirror and a rear projection screen. The mirror and screen are at angles effective to reflect and receive, respectively, an aerial image of the television image formed by the image projection means of the stationary optical assembly. The angles are also effective for nesting the mirror and the screen with components of the stationary optical assembly. The optical system, when retracted and nested is overall depth-wise-shallow and the receiver is as compact as a conventional, large-screen console television receiver. When the system is protracted within the narrow spatial column the receiver remains depth-wise-shallow, yet it is capable of displaying an image with an area greater than three times the image area of the conventional, large-screen console television receiver.

Optical system for projection television

A projection television system having three different primary color pitcure tubes in an in-line configuration, one centrally located on the projection screen axis and the other two on opposite sides of the axis. In order to compensate for the defocussing which these off-axis locations produce at the edges of the projected image, the off-axis picture tubes are rotated relative to the optical axes of their respective focussing lenses, thus rotating the corresponding projected images into coincidence with the projection screen. The off-axis positioning also produces color shading by making the square law fall-off in illumination vary across the projection screen, and also by producing a trapezoidal distortion which is compensated by pre-distortion which introduces additional color shading effects. The first effect is reduced by making the lenses tangent or nearly tangent to each other, thus minimizing the angular deviation of the projection axes. The second effect results from the use of slanted CRT electron guns to achieve the compensatory trapezoidal pre-distortion of the off-axis object images, and is corrected by laterally offsetting these object images (CRT rasters) from the optical axes of their focussing lenses. This off-set can be achieved by laterally displacing the entire picture tube, or by laterally displacing the electron gun relative to the tube faceplate, or by magnetically deflecting the electron beam. The degree of offset is preferably such as to equalize the distances of all object image corner points from the lens axis. The offset then must itself be compensated by rotating the off-axis lenses so that their optical axes are underconverged.

Color projection TV systems

A color television receiver system has a cathode ray picture tube including an imaging faceplate having deposits of multi-color phosphor targets thereon. The tube includes a three-beam electron gun and a color selection aperture mask having apertures in registration with the targets. A beam-current-control signal is derived from the scansion circuit means of the receiver system; the amplitude of the signal varies monotonically as a function of the distance of the beams from the center of the faceplate. Means are provided for receiving the beam-current-control signal for modulating the receiver system luminance signal with the beam-current-control signal, which has such characteristics that the modulation causes a predetermined gradational reduction in beam current as a function of the distance of the beam from the center of the faceplate. The benefits include enhanced color purity and improved resolution, and energy savings.

Television picture tube having enhanced resolution and color purity

This disclosure depicts a novel apparatus for use in a shadow mask type color television picture tube having a funnel and a faceplate attached to the mouth of the funnel. The faceplate has an electron excitable phosphor screen having triads of red, green and blue phosphor elements deposited thereon and an apertured shadow mask in spaced adjacency to the phosphor screen. The funnel has a neck containing an electron gun assembly for forming three electron beams. The apertures in the shadow mask form beam landing areas on the phosphor elements when the electrons pass through the apertures. This invention is a system for increasing color purity tolerance and leaving tolerance in at least a portion of a predetermined sector of the phosphor screen and shadow mask assembly to increase tolerance to radial registration errors between the electron beam landing areas and the phosphor elements due to shadow mask doming during operation of the tube. The geometry of the beam landing areas and the phosphor elements in the portion of the sector are characterized by having off the tube axis the smaller ones of the phosphor elements and the mask apertures radially compressed relative to the larger ones without a corresponding azimuthal compression. The radial compressing increases with increasing radius such that the tolerances in the radial direction increase off axis without a corresponding increase in azimuthal tolerance. This provides increased tolerance to the aforesaid doming-induced registration errors between the phosphor elements and the beam landing areas.

Growing community of inventors

Palatine, IL, United States of America

William A Rowe