North American Philips Consumer Electronics Corp.

Gte Sylvania Incorporated

Gte Products Corporation

Anthony V Gallaro

G Norman Williams

Gordon T Foreman

Robert A Hedler

Mahlon B Fisher

George N Williams

Martin Fischman

Charles H Rehkopf

William E Buescher

Charles A Davis

Ralph E Neuber

Robert L Bergamo

Joseph E Lane

Frederick A Hovey

Judy A Nagel

Mark A Josephs

William J Sember

Steven A Baum

Cathode ray tubes with optical windows in the sidewall or funnel portion thereof are provided with transparent conductive films of metal oxide on the inner surface of the funnel in the window area. Such films provide electrical continuity with the internal conductive coating of the tube, while permitting optical viewing. The films are produced by in-situ pyrolysis of films of metal resiantes in organic solvents.

CRT with optical window and method

A color cathode ray tube having feedback features including a phosphor pattern on the mask and a window in the tube wall to allow external detection of the phosphor emissions, also incorporates arc limiting features including a high resistance coating in the neck region of the tube and a lower resistance coating underneath the arc limiting coating in the region of electrical contact between the arc limiting coating and the electron gun. The composite coating is effective to reduce erosion of the arc limiting coating in the area of snubber contact during high voltage conditioning of the tube. Such a tube is useful, for example, for high resolution color displays having an automatic convergence feature.

Color CRT with composite arc suppression structure

A color cathode ray tube having a phosphor pattern on the mask and a window in the tube wall to allow external detection of the phosphor emissions, also incorporates arc limiting features including a high resistance coating in the neck region of the tube and a getter designed and placed to direct getter flash away from the neck, window and mask areas. Such a tube is useful, for example, for high resolution color displays having an automatic convergence feature.

Color CRT with arc suppression structure

The invention provides efficient means for dissipating deleterious charge build-up in the glass neck portion of a color cathode ray tube employing an in-line plural beam electron gun assembly. In one embodiment, the invention is comprised of two longitudinal stripes of electrical conductive material oppositely applied on the neck substantially over both narrow sides of the gun assembly. Connective conductors join the stripes to the grounded funnel coating to provide for dissipation of the charge. In another embodiment, the longitudinal stripes are joined by two band-like layers encompassing inter-electrode spacings of the gun assembly.

External neck charge dissipation means for an in-line color cathode ray

CRT with optical window

Phosphor characters to supply feedback information for an automatic convergence system are applied to the gun side of the shadow mask of a color cathode ray tube by a method of applying layers of a positive-working photoresist and phosphor, exposing the layers through a positive photomask, back exposing to clear the shadow mask apertures, developing to remove the exposed areas, and baking to remove the photoresist.

Photographic process for applying phosphor pattern to color CRT shadow

Fine particle size phosphors are adhered to the back of the aperture mask of a cathode ray tube by spraying a dispersion of such particles in a coating vehicle containing a temporary binder, and baking to remove the binder. The adhered phosphor is useful in providing information about the location of the scanning electron beams during tube operation.

Process for applying phosphor to the aperture mask of a cathode ray tube

The invention provides an advantageous blend of green and orange-emitting phosphors to constitute an improved substantially yellow-emitting screen component in a data display CRT. The blended component evidences medium-long persistence and thereby provides substantially flicker-free imagery when the tube is expeditiously employed in conjunction with field refresh rates of 20 to 40 Hz.

Data display CRT having a yellow-emitting screen

The invention provides an advantageous blend of green, orange and blue-emitting phosphors to constitute an improved white-emitting screen component in a data display CRT. The improved white-emitter evidences medium-long persistence and thereby provides flicker-free imagery when the tube is expeditiously employed in conjunction with field refresh rates of 20 to 40 Hz.

Data display CRT having a white-emitting screen

A cathode ray tube includes an evacuated envelope having an inner surface supporting an arc limiting coating which includes insulator oxide particles, graphite particles and a silicate binder and is characterized by the improvement of insulator oxide particles having an exothermic heat of formation greater than the exothermic heat of formation of iron oxide.

Cathode ray tube arc limiting coating

Arc suppressor coating structures with enhanced limiting characteristics for color cathode ray tubes are achieved by employment of a high electrical resistance coating (30) having, in a specific area, an extremely high resistance (i.e., insulator) coating (46) thereon which provides a seating area for an antenna getter mounted upon the electron gun. The insulator coating is preferably comprised of about 71.2% Fe.sub.2 O.sub.3 and 28.2% K.sub.2 SiO.sub.3. Insulating the antenna getter from, the high resistance coating reduces electrical shorts and keeps arc currents within the range of less than 40 amps. Such results were not previously achievable with antenna getter usage.

Cathode ray tube arc suppressor coating

A color cathode ray tube screen structure, having means for enhancing the absorption of ambient light and providing improvement in the contrast of the image display, is comprised of three superimposed substantially continuous window-defining layers of optical filter materials. The primary, secondary and tertiary filter layers have discretely disposed window areas formed therein to expose a pattern of filter areas representing the respective filter materials. The filter windows are of a shaping similar to that of the apertures in a spatially related pattern mask member. Each window exhibits a uniform periphery free of indentations, being so defined by a uniform opaque interstitial encompassment homogeneously made up of the three distinct layers of filter materials. Disposed over the filter windows is a patterned screen of cathodoluminescent phosphor elements, which upon electron excitation produces color-emissions that are colormetrically related to the respective filter windows therebeneath.

Color cathode ray tube screen structure providing improved contrast

A high resistive electrical conductive coating of discrete composition is provided for band-like deposition in a defined area of the interior surface of substantially the funnel member of a cathode ray tube envelope between the region of the high potential transversal therethrough and the electron generating means oriented in the contiguous neck portion. The coating is an amorphous deposition of a homogeneous mixture of a vitreous substantially insulative frit material admixed with at least one particulate material selected from the group consisting essentially of cadmium oxide, indium oxide and copper oxide wherein the individual particles of the respective oxide ingredients are uniformly dispersed and encapsulated to provide a discretely defined resistive structural means for effecting arc suppression in the region of the electron generating assembly.

Resistive electrical conductive coating for use in a cathode ray tube

A method is provided for disposing a tripartite electrical connective-resistive system of related coating areas upon interior portions of a cathode ray tube envelope to effect arc suppression in the region of the electron generating assembly. The tripartite means is comprised of a first low resistive electrical conductive coating disposed on the forward portion of the envelope. A durable high resistive electrical conductive coating is disposed contiguous to and rearward of the first coating extending therefrom to the neck of the envelope. This resistive coating is an amorphous deposition of a homogeneous composition of an insulative vitreous frit material admixed with at least one particulate material selected from the group consisting essentially of cadmium oxide, indium oxide and copper oxide. The third component of the system is a second low resistive electrical conductive coating exhibiting a scratch-resistant surface disposed as a circumferential band in the forward portion of the neck member, being contiguous with the rear boundary of the high resistive coating.

Method of depositing tripartite coating system for a cathode ray tube

An improvement combination is provided in cathode ray tube construction for expediting improved tube processing and subsequent tube operation. The combination is incorporated in the funnel portion of the tube wherein a first low resistive electrical conductive coating is interiorly disposed in a substantially circumferential manner on the forward portion of the funnel nearest the screen. A high resistive electrical conductive coating is substantially circumferentially interiorly disposed on substantially the intermediate portion of the funnel being contiguous with the first coating, and making contact with a second low resistive electrical conductive coating interiorly disposed on substantially the rear portion of the funnel. This second coating extends into the forward region of the integral neck portion to facilitate electrical connection with the electron gun assembly positioned therein. A first button connector is oriented to traverse the wall of the forward region of the funnel and make connection with the first low resistive coating. Rearward from the first button, a second button connector traverses the wall of the funnel to provide a separate electrical connection for the second low resistive coating. During tube processing, utilization of this second button facilitates high voltage conditioning of the electron gun assembly by by-passing the high resistance coating; while in subsequent tube operation only the first button connector is utilized thereby effecting beneficial arc protection by incorporating the high resistive coating into the circuit.

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Auburn, NY, United States of America

Anthony V Gallaro