Zenith Electronics Corporation

Zenith Radio Corporation

Charles J Prazak

Robert J Adler

Paul Strauss

James R Fendley

Howard G Lange

Johann Steiner

Lawrence W Dougherty

Kazimir Palac

Wayne R Chiodi

Philomena C Libman

Yong S Park

Johan Steiner

Method and apparatus are disclosed for tensioning uniform foil shadow masks by clamping the edges of a mask and moving the clamps through a preselected fixed displacement, thereby obviating the need for extensive controls on the tensioning process.

Mechanically indexed mask stretching apparatus

Process and apparatus are disclosed for use in the manufacture of a color cathode ray tube having a shadow mask with a central pattern of apertures mounted in tension on a transparent flat front panel. The mask aperture pattern is registered with a cathodoluminescent screen pattern of corresponding geometry and position on an inner surface of the panel. The shadow masks and front panels are respectively interchangeable. In a preferred arrangement, signals are developed which are indicative of the positions of a mechanically stretched mask aperture pattern and an associated front panel screen pattern relative to a reference or to each other. Responsive to such signals, there is effected a relative positioning of the mask and screen until registration between the patterns is achieved.

Method and apparatus for making flat tension mask color cathode ray tubes

A method is disclosed for use in the manufacture of a color cathode ray tube having a foil tension mask with a central pattern of apertures. A transparent flat front panel has a cathodoluminescent screen pattern on its inner surface. A plurality of mask support means, located on opposed sides of the screen pattern, have respective mask-receiving surfaces for receiving a shadow mask in tension. Q-height error data is developed according to the invention, and the aperture pattern of the mask in expanded and positioned in response to the error data to compensate for errors in Q-height to bring the mask apertures into registry with the screen pattern. Apparatus for measuring Q-height is also disclosed.

Process and apparatus are disclosed for use in the manufacture of a color cathode ray tube having a shadow mask with a central pattern of apertures mounted in tension on a transparent flat front panel. The mask aperture pattern is registered with a catholdoluminescent screen pattern of corresponding geometry and position on an inner surface of the panel. The shadow masks and front panels are respectively interchangeable. Signals are developed which are indicative of the positions of a mechanically stretched mask aperture pattern and an associated front panel screen pattern relative to a reference or to each other. Responsive to such signals, there is effected a relative positioning of the mask and screen until registration between the patterns is achieved.

This disclosure describes method and apparatus useful in the manufacture of shadow mask color cathode ray tubes of the flat tension mask type, wherein the shadow masks and associated glass front panels are respectively interchangeable during mask-panel assembly.

Methods and apparatus for making flat tension mask color cathode ray

An improved cataphoretic process is disclosed for use in the manufacture of a color cathode ray tube. The process provides for depositing in sequence on the tube screening surface at least two separate patterns of phosphor elements, with each pattern of elements capable of emitting light of a different color when excited. The process according to the invention comprises first depositing an electrically conductive coating over the screening surface for use as an electrode during each deposition operation. Second, an electrically insulative barrier is deposited over the conductive coating. Portions of the barrier are removed selectively and sequentially for controlling patterned, sequenced cataphoretic access to the electrically conductive coating.

Cataphoretic process for screening color cathode ray tubes

A front assembly is disclosed for a tension mask color cathode ray tube. The assembly comprises a faceplate having a tensed foil shadow mask supported by mask support means, and means for shielding the faceplate from a high-energy beam used to trim waste material from the mask following its attachment to the mask support means.

Front assembly for a tension mask color cathode ray tube having a

Inner specular reflection is suppressed in a flat faceplate for use in a color cathode ray tube (CRT) by forming a flat glass faceplate to have an aft, or inner surface characterized by an undefined roughness. By allowing for an aft surface of undefined roughness, a subsequent lapping process is utilized to produce a predetermined roughness of the aft surface that will substantially eliminate specular reflection from that surface.

Inner surface specular reflection suppression in flat CRT faceplate

A planar tension mask is disclosed for use in a color cathode ray tube having a substantially flat faceplate. The shadow mask according to the invention has an aperture pattern characterized by the vertical pitch of the apertures being constant, but with the horizontal pitch of the apetures increasing outwardly from the mask center according to a function which is parabolic with horizontal displacement, and parabolic with vertical displacement. The horizontal pitch increase is isotropic in the sense that the increase in pitch is the sum of the horizontal displacement increase and the vertical displacement increase. A color cathode ray tube front assembly having such a shadow mask is also disclosed.

Flat tension mask color CRT front assembly with improved mask for

A shadow mask blank is disclosed for use in the manufacture of an ultra-high resolution color cathode tube. The mask blank is adapted to be expanded and secured under tension in spaced adjacency to the screen of the tube. The blank comprises a central field of electron-beam-passing apertures, an outer band adapted to be gripped during the expanding, and at least one field of selectively weakened metal between the central field and the outer band. The selectively weakened metal is effective to equalize stress and prevent wrinkling of the blank under electron beam heating when the blank is expanded and secured under tension. An inner band peripheral to the central field may be provided for mounting the blank on a support structure and securing it thereto. Means may also be provided for linking the inner band with the outer band to selectively strengthen weakened areas.

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

An assembly-in-process consisting of three components-in-process is disclosed. The components-in-process comprise, respectively, a faceplate with a sealing area circumscribing a target area including of plurality of first registration-affording V-grooves; secondly, a shadow mask support assembly having a frame ultimately constituting a part of the tube envelope, and a sealing area having a like plurality of registration-affording V-grooves in alignment with the first V-grooves; and third, a like plurality of balls disposed between the mated first and second V-grooves for establishing precise registration between the faceplate and the frame in the process of screening a pattern of phosphor deposits on the target area and later in the final assembly of the tube. The assembly-in-process is characterized by the use of temporary cementing means for attaching the balls to either the first or second ones of the V-grooves, whereby the components-in-process can be reproducibly registered and re-registered in precise relationship during screening and later in final assembly of the tube. A method for use in manufacture is also disclosed.

Process of manufacturing for a high-resolution color cathode ray tube

A glass faceplate for use in a color cathode ray tube has a target area with a pattern of phosphor deposits circumscribed by a sealing area, and a frame supporting a shadow mask with a sealing area geometrically matching the sealing area of the faceplate. Three indexing means are spaced apart along the sealing areas for indexing the faceplate in relation to the frame, providing a gap of predetermined width, and leaving at least one corner of the faceplate unsupported. Shims means having shimming dimension equivalent to or slightly less than the predetermined gap width is located in the gap at the unsupported corner, whereby the unsupported corner is supported by the shim means such that the predetermined gap width is maintained during tube fabrication even at the unsupported corner. A method for assembling a color cathode ray tube which utilizes the shimming means according to the invention is also disclosed.

Registration-enhancing means and method for color cathode ray tubes

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.

This disclosure depicts method and apparatus for screening slot-mask, stripe screen type color cathode ray tubes particularly method and apparatus for improving screen stripe uniformity and edge definition. The method involves supporting a curved, approximately rectangular faceplate which has on its concave inner surface a photosensitive coating and which has supported adjacent its inner surface an exposure mask defining an array of columns of spaced slots oriented parallel to the minor axis of the faceplate. A line source of radiation actinic to said coating is supported on or near a central axis of the faceplate. The disclosed method includes producing a virtual image of the line source which appears, when viewed from off-axis points on the faceplate, to be rotated in a direction effective to decrease an unwanted rotational displacement of the mask slot images induced by the relative geometry of the line source, the mask slots and the faceplate inner surface. Stripe width uniformity and edge definition is thus improved. Preferred apparatus for implementing the disclosed method includes a negative meniscus lens.

Method and apparatus for screening slot-mask, stripe screen color

This disclosure depicts a non-settling process for forming on an inner viewing surface of a color cathode ray tube faceplate, a coating of an aqueous slurry composed of an organic binder and a suspension of particulate phosphor material of distributed particle size, which coating exhibits an extraordinarily suppressed radial streaking, a high degree of coating weight uniformity, and a predictable particle size distribution. The process comprises supporting the faceplate such that the central axis of the faceplate has a substantial horizontal component and slowly rotating the faceplate about the central axis thereof while dispensing a stream of phosphor slurry having a predetermined phosphor particle size distribution onto the central region of the faceplate inner surface, preferably substantially at the axis of rotation, such that due to gravitational forces and the slow rotation of the faceplate through the descending slurry stream, the slurry is suffused to the perimeter of the faceplate inner surface without any significant settling out of the phosphor particles onto the faceplate. The coating is then levigated by rotating the coated faceplate at a moderate angular velocity for a brief time interval, the joint effect of which moderate angular velocity and brief time interval being to level the coating down to a predetermined thickness while suppressing the formation of radial streaks in the coating radially outward of irregularities in or on the faceplate inner surface.

Growing community of inventors

Elmhurst, IL, United States of America

Charles J Prazak