Zenith Electronics Corporation

Zenith Radio Corporation

Leonard Dietch

James R Fendley

Paul Strauss

Kazimir Palac

Raymond G Capek

James W Schwartz

John M Jarosz

Michael Livshits

Anthony Cocco

A color cathode ray tube is disclosed having a front assembly with a shadow mask characterized by having circular apertures at the mask center, and apertures at least in the mask periphery increasingly elongated radially outwardly as a function of distance from the center. The elongation of the apertures is effective to reduce or eliminate the distortion of the deposits on the mask periphery produced by diffraction effects during photoscreening, and to form phosphor deposits compatible in size and shape with the electron beamlets. The screen of the tube according to the invention may have circular or near-circular phosphor deposits thereon. Tube types to which the invention can be applied include the conventional curved-screen/curved-mask tube, and the substantially flat faceplate tube that has a foil shadow mask suspended in tension a predetermined distance from the screening surface. A method is also disclosed for use in the photo-fabrication of a faceplate for an ultra-high resolution color cathode ray tube.

Front assembly for an ultra-high resolution color cathode ray tube

A front assembly for a color cathode ray tube includes a faceplate having a peripheral sealing area adapted to mate with a funnel, with a centrally disposed phosphor screen. The assembly according to the invention includes a separate shadow mask support structure composed of ceramic material secured to the faceplate inner surface on opposed sides of the screen and within the sealing area for receiving and supporting a foil shadow mask in tension a predetermined distance from the screen. Other configurative aspects include a separate continuous or discontinuous metal cap or strip secured to the support structure for receiving and securing a mask, and a mask support structure comprising four discrete rails composed of ceramic with weldable metal strip means for interconnecting the rails to form a generally rectangular unitary shadow mask support structure. The ceramic may also serve as a 'buffer' for compensating for the difference in thermal coefficients of the glass of the faceplate and the metal of the cap or strip.

Support means for a tensioned foil shadow mask

A component-in-process for use in the manufacture of a color cathode ray tube comprises a shadow mask having a pattern of minute apertures for color selection the mask according to the invention has disposed on at least one side thereof a removable film effective to prevent particle occlusion of the apertures. The film according to the invention has an extremely small, substantially uniform thickness dimension, a low index of refraction, and is of such high transparency as to exhibit a negligible optical effect during photoscreening operations. An associated manufacturing method for a cathode ray tube is also disclosed.

Shadow mask having aperture occlusion prevention means

A method is disclosed for use in the manufacture of a color cathode ray tube having a shadow mask with a pattern of minute apertures for color selection. A removable film effective to prevent particle occlusion of the apertures is disposed on at least one side of the mask. The film has an extremely small, substantially uniform thickness dimension, a low index of refraction, and is of such high transparency as to exhibit a negligible optical effect during photoscreening operations.

Method for shadow mask protection during manufacture

A tension mask color cathode ray tube comprises an envelope funnel having a central axis and including a bell portion, one extremity of which has a sealing land. A flat or cylindrical face panel has a target adapted to receive a pattern of luminescent primary color elemental phosphor areas, with a sealing land circumscribing the target. A color selection electrode structure sealed between the sealing lands of the funnel and panel constitutes an integral part of the tube envelope. The electrode structure has a central opening dimensioned to enclose the panel target, and includes a frame supporting a tensed foil color selection electrode. The frame has a support surface fixedly receiving and maintaining the electrode in tension. The frame further has an axial dimension which establishes the color selection electrode at a predetermined Q-distance from the target on the face panel.

Tension mask colar cathode ray tube

A coaxial cable isolator includes ceramic capacitive and inductive elements for isolating the cable sheath from low frequency power current while passing high frequency television signal current. A ceramic resistance ring is positioned inside the isolator and forms a gap with the inner conductor thereof for precluding rapid buildup of voltage across the interruption in the isolator by discharging high energy currents thereacross. The ceramic material has about 15,000 ohms resistance for precluding power follow-through current after occurrence of a high energy discharge.

Cable isolator with overvoltage protection

This disclosure depicts a television picture tube subject to an undesired build-up of localized high-potential static charges and high-potential charge retention. The tube is characterized by a resistive coating deposited on at least one of the normally uncoated outer areas of the tube and in contact with the conductive coating to disperse any static charges by means of a flow of electrons through the resistive coating. The 'rush' of electrons which may cause an annoying crackling sound upon tube turn-on and turn-off is attenuated thereby to suppress the sound, and any residual high-potential charges remaining after turn-off are discharged to ground.

High potential static discharge means for television cathode ray tubes

A color cathode-ray tube having a phosphor screen including a pattern of red-emitting, blue-emitting and green-emitting phosphor deposits. Electron gun means generates first, second and third angularly spaced electron beams for exciting the phosphor elements. A parallax mask is disposed adjacent the screen and has a pattern of openings for causing the first, second and third electron beams to impinge exclusively on the red-emitting, blue-emitting and green-emitting phosphor deposits, respectively. The openings in the mask and the phosphor deposits are dimensioned relative to each other such that the beam spots formed through the mask openings and the respectively associated phosphor deposits have a relative dimensional difference which varies between the central portion and the peripheral portions of the screen from a condition in which the beam spots have a greater dimension than the associated phosphor deposits to a condition in which the beam spots have a dimension smaller than the associated phosphor deposits. The screen has light absorptive material between the phosphor deposits in at least those portions of the screen wherein the said beam spot dimension is larger than the associated phosphor deposit dimension.

Black-surround color picture tube

An image screen structure for a monochrome or a color cathode-ray tube, in which the phosphor screen is interposed between a composite mesh and the conventional reflective metal backing layer. The composite mesh comprises a reflective grille and a non-reflective grille in registration with the reflective grille. The reflective grille faces the phosphor screen so that light generated by phosphor excitation behind the non-reflective grille finds egress by multiple reflections between the reflective grille and the metal backing layer. In a color cathode-ray tube such as a tri-color shadow-mask television picture tube, the non-reflective and reflective grilles may be non-coherent with the mosaic phosphor screen, thus avoiding the necessity of complicated and costly processing which has been employed in the manufacture of black-surround color picture tubes. A substantial improvement in brightness/contrast performance is obtained as compared with the best prior art monochrome and color cathode-ray tubes.

Growing community of inventors

Skokie, IL, United States of America

Leonard Dietch