Rca Inc.

Thomson Consumer Electronics Inc.

Rca Licensing Corporation

Ralph J D'Amato

Richard H Godfrey

Frank R Ragland, Jr

Albert M Morrell

Robert P Stone

Rein R Mutso

Richard A Nolan

The magnetic performance of a color CRT is optimized by firing ferromagnetic components thereof in an exothermic atmosphere to anneal the components and form a stable black iron oxide layer on a surface thereof. The components are introduced into a furnace having such an atmosphere and the components are heated to a temperature sufficient to initiate pre-oxidation of the surface thereof. The temperature is then increased to optimize the magnetic characteristics of the components and at least partially relieve stress therein. The components are next cooled to a temperature at which the thickness of the stable black oxide layer on the surface of the components is optimized. A CRT is manufactured according to the process described above.

Method of manufacturing a color CRT to optimize the magnetic performance

An internal magnetic shield for a color picture tube has lower reluctance in the sides of the shield than the top and bottom of the shield.

Color picture tube having an improved internal magnetic shield

The present invention provides an improvement in the appearance of a cathode-ray tube including a rectangular faceplate with an exterior surface having curvature along both the minor and major axes. The faceplate also includes a cathodoluminescent screen on an interior surface thereof. At least in the center portion of the faceplate, the curvature along the minor axis is at least 10 percent greater than the curvature along the major axis. Points on the exterior surface near the ends of the major axis, at the edges of the screen, lie in a first plane which is perpendicular to the central longitudinal axis of the tube; points on the exterior surface near the ends of the minor axis, at the edges of the screen, lie in a second plane which is spaced from and parallel to the first plane; and points on the exterior surface near the ends of the diagonals of the rectangular faceplate, at the edges of the screen, lie in a third plane which is spaced from and parallel to the first plane. The three planes are spaced from the center portion of the faceplate in the order of second plane, first plane and third plane.

Cathode-ray tube having faceplate panel with essentially planar screen

An improved color picture tube according to the invention includes a faceplate panel having a cathodoluminescent screen thereon. A low expansion color-selection electrode is mounted in the faceplate panel by a support structure including a bimetal element. The support structure is responsive to changes in temperature of the faceplate panel and moves the color selection electrode relative to the screen.

Support means for use with a low expansion color-selection electrode

A shadow mask type cathode-ray tube includes a rectangular faceplate having curvature along its minor axis but no curvature along its major axis. The shadow mask of the tube also has curvature along its minor axis and no curvature along its major axis. The mask is of a type of steel having a linear coefficient of thermal expansion of less than 3.times.10.sup.-6 .DELTA.l/l/.degree.C.

Cathode-ray tube having cylindrical faceplate and shadow mask with minor

An improved cathode-ray tube includes an envelope comprising a faceplate panel, a funnel and a neck. The faceplate panel includes a transparent rectangular faceplate having a cathodoluminescent screen on an interior surface thereof. The faceplate has a vertical minor axis and a horizontal major axis. The improvement comprises the thickness of the faceplate being less near the ends of at least one of the major or minor axes than at its center, whereby the viewing angle in at least one direction is increased. In a preferred embodiment, the thickness of the faceplate increases from center-to-edge along its minor axis and decreases from center-to-edge along its major axis.

Cathode-ray tube having a faceplate with decreasing center-to-edge

The present invention is an improvement in a method and apparatus for screening a line screen slit mask color picture tube. Such method includes coating a faceplate panel of the tube with a photosensitive material, inserting a slit shadow mask into the panel, and exposing the photosensitive material by passing light from a line light source through the slits of the mask. The improvement comprises positioning, between the light source and the shadow mask, means for varying the effective length of the line light source when viewed from different locations on the faceplate panel. In a preferred embodiment, the means for varying the effective length of the line light source are curved louvers placed adjacent the light source which, when viewed from the center of the panel, shadow the ends of the light source, but which, when viewed from the ends of the minor axis of the panel, expose an effectively longer light source. In another preferred embodiment, striped patterns on a glass plate are used to effect a similar result.

Method and apparatus for screening line screen slit mask color picture

An electron gun having at least one arc-suppression resistor located in a zero electric field gradient area of the electron gun is described. In the electron gun, at least one cathode is provided for generating an electron beam. A plurality of electrodes are also provided for directing the beam along the beam path. The electrodes include at least one accelerating and focusing electrode which is a split member having two spaced apart sections. The electron gun also includes at least one arc-suppression resistor which interconnects the spaced apart sections of the split electrode and is located in a zero electric field gradient area of the split member.

Arc suppression structure for an electron gun

An electron gun comprises a cathode for generating at least one electron beam along a beam path and a plurality of electrodes spaced along the beam path from the cathode. The electrode adjacent to the cathode comprises an electrically conductive base member of a first material having an aperture extending therethrough. The base member has two opposing surfaces that have overlying layers of a second electrically conductive material disposed thereon. The overlying layers overhang the aperture in the base member. At least one of the overlying layers has a plurality of apertures therethrough.

Electrode for an electron gun

A method of making a grid for a cathode-ray tube includes the process of etching an electrically conductive base member of a first material from two sides through related openings in electrically conductive layers of a second material which overlays the two sides of the base material. Etching continues until an aperture of sufficient size is formed that the overlying layers overhang the aperture in the base member.

Method of making a grid for a cathode-ray tube electron gun

The present invention provides an improvement in a corrugated apertured mask type color picture tube. The mask corrugations are substantially parallel and the mask has slit shaped apertures aligned in columns which are parallel to the mask corrugations and perpendicular to a major axis of the mask. The slits in each column are separated by web portions of the mask. The distance between the centers of two consecutive webs is defined as the web repeat distance. The slits form an aperture array wherein the lengthwise dimension of the slit columns vary with location on the mask. The tube also includes an electron gun for generating a plurality of electron beams and means for scanning the beams in lines across the mask. The improvement comprises making the web repeat distance within a slit column proportional to the distance from the major axis of the mask to the mask intercept of any particular scan line.

Color picture tube having improved corrugated apertured mask

A projection kinescope comprises an evacuated envelope having a faceplate, a phosphor screen on the inner surface of the faceplate, and an electron gun. The electron gun generates a plurality of electron beams in a substantially vertical plane. The beams are directed to strike the screen at vertically-separated positions. A delay line is associated with an electron beam that is directed to strike the screen above another electron beam. The delay time of the delay line is sufficient to repeat the video information imparted by the electron beam first striking the same portion of the screen.

Projection kinescope and method of operation

An improvement is provided in an apertured mask type color picture tube having a substantially flat faceplate, a cathodoluminescent screen on the faceplate, a corrugated apertured mask adjacent the screen and electron gun means for producing and directing a plurality of electron beams through the mask to impinge upon the screen. The mask corrugations are substantially parallel and extend in a first direction with the varying corrugated waveform extending in a second direction. The mask includes an aperture width and/or an aperture-to-aperture spacing variation in the second direction which is a function of mask-to-screen spacing. The improvement comprises a further variation in aperture width and/or aperture-to-aperture spacing which is a function of (a) deflection angle of the electron beams, (b) the angle in a horizontal plane between tangents to the mask surface and a central contour through the mask, and (c) the angle in a horizontal plane between a tangent to the mask central contour and a plane perpendicular to the tube central longitudinal axis. In an additional improvement, aperture width also is varied because of the effective mask thickness or aperture step height.

Color picture tube having improved corrugated mask

The present invention provides an improvement in an apertured mask type color picture tube having a faceplate, a cathodoluminescent screen on the faceplate, a corrugated apertured mask adjacent the screen and an electron gun means for producing and directing a plurality of electron beams through the mask to impinge upon the screen. The mask is constructed by first forming the apertures therein and thereafter forming the mask in a corrugated shape. Aperture width in the apertured but unformed mask is adjusted to compensate for stretching and compression of the mask occurring during formation of the mask into a corrugated shape. Therefore, the corrugated mask is substantially free of aperture width variation from that desired caused by forming the mask in a corrugated shape.

Color picture tube having improved corrugated apertured mask and method

The process includes exposing a photosensitive coating on a surface of the faceplate panel of a tube with actinic radiation passed through a patterned screen master, developing the panel coating and then mounting a formed imperforate member to the panel. A photosensitive coating on the imperforate member is exposed with actinic radiation passed through a patterned color selection electrode master while the imperforate member is mounted to the panel. The imperforate member coating is then developed and the imperforate member is etched to form an apertured color selection electrode.

Growing community of inventors

Lancaster, PA, United States of America

Ralph J D'Amato