Zenith Electronics Corporation

Zenith Radio Corporation

Kazimir Palac

Raymond M Stachniak

Sae D Lee

Paul Strauss

Lawrence W Dougherty

Charles J Prazak

Siegfried M Greiner

Leonard Dietch

A novel color selection electrode assembly is utilized in screening a pattern of phosphor areas upon the faceplate of a color cathode ray tube. The faceplate, which is formed of a material having a predetermined temperature coefficient of expansion, has registration affording means. The aforesaid assembly comprises an auxiliary mount formed of a material having a temperature coefficient of expansion greater than that of the faceplate and has a central opening of such span as to enable the mount to surround the periphery of the faceplate. Index bosses, cooperable with the faceplate registration affording means, are detachably secured to the mount. A planar metal foil having a predetermined pattern of apertures and formed of a material having a temperature coefficient of expansion not greater than that of the mount is secured to the mount. The index bosses cooperate with the registration affording means on the envelope to permit repeated precise registrations between the foil and the faceplate to facilitate screening of the phosphor pattern as well as to facilitate mating of the electrode assembly to the faceplate. Finally, the invention contemplates a method of utilizing the electrode assembly for screening a phosphor pattern as well as methods of making a color cathode ray tube having such an electrode assembly.

Method of mounting tensed CRT mask

A front assembly for a tension mask color cathode ray tube comprises a faceplate having an inner surface thereon for receiving a pattern of luminescent phosphor elements. A foil mask is supported in tension by the faceplate and has a pattern of apertures registered with the pattern of phosphor elements. The assembly is characterized by the faceplate having registration affording means disposed on the external periphery of the faceplate outside the tube vacuum enclosure constructed and arranged to permit repeatable precise registration between said foil mask and said faceplate to facilitate screening the pattern of phosphor elements upon the faceplate inner surface. By having the registration affording means located externally of the tube enclosure, the viewable area of the inner surface is maximized and the faceplate size for a given screen area is reduced.

Tension mask color cathode ray tube component with external

Components-in process and assemblies-in-process are disclosed for use in the manufacture of a high-resolution color cathode ray tube having a tensed foil shadow mask. A first component-in-process comprises a faceplate with a target area for receiving at least one pattern of phosphor deposits. The faceplate has attached at preselected, widely spaced locations on the sides thereof a plurality of discrete, detachable first indexing elements. A second component-in-process comprises a shadow mask support assembly having a frame ultimately constituting a part of the tube envelope; the frame supports the shadow mask in precise adjacency to the target area. The frame has attached on the sides thereof a like plurality of discrete, detachable second indexing elements which are in facing adjacency to the first indexing elements on the faceplate when the faceplate and frame are mated. Temporary attachment of the indexing elements is by means of a thermally degradable cement. The faceplate and frame can be inter-registered in precise relationship by the temporary use of the first and second indexing elements in the process of screening the pattern of phosphor deposits on the target area and later in the final assembly of the tube. Also disclosed is a method of manufacture of a high-resolution cathode ray tube by the detachable indexing elements according to the invention.

Means and method for manufacture for a high-resolution color cathode ray

Removable screening mount for a tensed mask cathode ray tube

Tensed mask cathode ray tube

In-process articles of manufacture are disclosed for the manufacture of a high-resolution color cathode ray tube having a tensed foil shadow mask. A first article-in-process comprises a faceplate with a target area for receiving at least one pattern of phosphor deposits. The faceplate has attached at preselected, widely spaced locations on the sides thereof a plurality of discrete, detachable first indexing elements. An article-in-process comprises a shadow mask support assembly having a frame ultimately constituting a part of the tube envelope; the frame supports the shadow mask in precise adjacency to the target area. The frame has attached on the sides thereof a like plurality of discrete, detachable second indexing elements which are in facing adjacency to the first indexing elements on the faceplate when the faceplate and frame are mated. Temporary attachment of the indexing elements is by means of a thermally degradable cement. The faceplate and frame can be inter-registered in precise relationship by the temporary use of the first and second indexing elements in the process of screening the pattern of phosphor deposits on the target area and later in the final assembly of the tube. Also disclosed is a method of manufacture of a high-resolution cathode ray tube by the detachable indexing elements according to the invention.

Means and method for manufacture of a high-resolution color cathode ray

A front assembly is disclosed for use in a color cathode ray tube. The assembly according to the invention comprises a glass faceplate having a target area with a pattern of phosphor deposits covered with an electron-pervious electrically conductive metallic film. A shadow mask support assembly includes a glass frame sealed to and constituting an integral part of the tube envelope for supporting a shadow mask in precise spaced adjacency to the target area. The frame has an electrically conductive frame coating on at least a portion thereof. An electrically conductive foil shadow mask adapted to be charged with a high voltage is mounted in tension on the frame in electrical contact with a conductive frame coating. Conductive means which may comprise spring means is in contact with the mask or the conductive frame coating and the metallic film or a conductive extension thereof for conducting high voltage on the mask to the metallic film. A funnel has an anode button therethrough for receiving a high voltage, and anode spring means attached to the anode button and having a distal end in contact with the conductive frame coating for conducting the high voltage to the shadow mask. As a result, the high voltage applied to the anode button is conducted to the frame, the foil mask and the metallic film.

Color CRT tension mask support assembly with a glass frame

A flat panel tensed foil shadow mask registration system includes three radially disposed grooves on the panel and three oppositely disposed grooves on the frame that supports the tensed mask. Three spherical balls serve to align the panel and the frame in a precise relationship. The balls are permitted to roll in the grooves and one of the grooves in each pair is shorter than the other to restrict the range of positions of the ball in the other groove of each pair when the panel and frame are in the precise relationship.

Groove and ball registration system for a CRT flat panel

A method of screening a tensed mask CRT faceplate to correct for color purity errors resulting from screening of the tube through a tension mask whose supporting frame is distorted by the tensile forces exerted by the mask on the frame. The method includes heating the tensed mask during photoscreening of the tube to a temperature sufficient to substantially reduce the strain imparted to the support frame.

Method of screening a flat mask cathode ray tube

A novel color selection electrode assembly is utilized in screening a pattern of phosphor areas upon the faceplate of a color cathode ray tube. The faceplate, which is formed of a material having a predetermined temperature coefficient of expansion, has registration affording means. The aforesaid assembly comprises an auxiliary mount formed of a material having a temperature coefficient of expansion greater than that of the faceplate and has a central opening of such span as to enable the mount to surround the periphery of the faceplate. Index bosses, cooperable with the faceplate registration affording means, are detachably secured to the mount. A planar metal foil having a predetermined pattern of apertures and formed of a material having a temperature coefficient of expansion not greater than that of the mount is secured to the mount. The index bosses cooperate with the registration affording means on the envelope to permit repeated precise registrations between the foil and the faceplate to facilitate mating of the electrode assembly of the faceplate. Finally, the invention contemplates a method of utilizing the electrode assembly for screening a phosphor pattern as well as methods of making a color cathode ray tube having such an electrode assembly.

A color cathode ray tube comprises an envelope including a faceplate portion having on an inner surface a pattern of cathodoluminescent phosphors deposited thereon. The envelope includes a continuous peripheral support surface within the envelope spaced approximately a predetermined distance from the inner surface of the faceplate. The tube has a tensed foil aperture mask cemented to the support surface by cement means. The mask blank has a first field of apertures in coordinate relationship to the pattern of cathodoluminescent phosphors for color selection. A second field of apertures peripheral to the first field, and coordinate with the support surface, provides for receiving cementing means during assembly of the blank into a cathode ray tube. The apertures have the form of a band of substantially uniform width at least along the sides of the blank, and are small in diameter relative to the width of the band. Tabs extending from the sides of the blank are used for tensing the blank, and are separable from the blank at parting lines. Tear perforations located on the parting lines provide for tearing the tabs from the mask blank upon installation.

Color cathode ray tube and tensible shadow mask blank for use therein

An improvement in a tension mask type color cathode ray tube comprising an envelope funnel that includes a bell portion, one extremity of which has a sealing land. The tube further comprises a flat face panel formed of a material having a predetermined temperature coefficient of expansion. The panel has a target area adapted to receive a pattern of luminescent color phosphor deposits. A sealing surface circumscribes the target areas. The improvement concerns a constituent structure which is disposed between the funnel sealing land and the panel sealing surface and which is frit sealed therebetween. The structure defines a central opening which is dimensioned to enclose the panel target area and it is formed of a material having a temperature coefficient of expansion approximating that of the face panel. The structure itself comprises means which define a support surface that confronts the target, which surface is adapted to fixedly receive a tensed color selection mask. Additionally, the structure includes means that serve to establish the tensed mask at a predetermined Q distance from the target area.

Tension mask mounting structure

A color cathode ray tube comprises a faceplate having a predetermined pattern of phosphor deposits upon a target surface thereof. A color selection electrode assembly includes a frame which supports in tension a foil having an array of apertures related to the predetermined pattern of phosphor deposits on the faceplate. Means are disclosed for sealing the assembly between the faceplate and the rear envelope section of the tube to incorporate the color selection electrode assembly as an integral part of the cathode ray tube. Indexing means on the assembly and faceplate provide for repeated interregistered matings of the color selection electrode assembly with the faceplate. A method of utilizing the electrode assembly for screening the pattern of phosphor deposits on the faceplate is also disclosed.

Tension mask cathode ray tube

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 method of making a color cathode ray tube is disclosed that utilizes a tensed color selection electrode assembly as a stencil for screening a pattern of luminescent phosphor deposits upon a faceplate. The faceplate has a target area and a peripheral sealing area and a plurality of registration-affording means at selected locations about its periphery. The faceplate is utilizable as a constituent of a color cathode ray tube. Electrode assembly comprises frame means to which is bonded a planar tensed foil. Means are provided for bonding the faceplate and the frame means such that the frame becomes an integral part of the vacuum envelope for the tube during final assembly of the tube. Indexing means mechanically associated with the frame and cooperable with the faceplate registration-affording means to facilitate multiple registered matings of the frame and the faceplate during the screening. The method according to the invention comprises applying a photosensitive coating to the target area; registering the frame with a faceplate to enable the foil to serve as a screen stencil; causing the coating to be exposed to radiation actinic thereto such that the latent image of the pattern formed in the photosensitive coating corresponds to the patterns of electron beam landings on the target area when the tube is finally assembled and operating; removing the frame means and processing the exposed coating. The method steps are repeated for each method of elemental phosphor deposits desired to be established. The faceplate screening area is then sealed to the frame sealing area with a registration-affording means and indexing means in mating registration, whereby the frame becomes an integral constituent of the cathode ray tube envelope.

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Carpentersville, IL, United States of America

Kazimir Palac