Abstract: A deflection yoke includes a first core portion and a core extension portion. The core extension portion is located in the rear of the yoke closer to the beam entrance region. To adjust the yoke for the particular cathode ray tube on which it is mounted, the position of the yoke is adjusted for obtaining acceptable image geometry. Then, the core extension is moved with respect to the first core portion in a direction perpendicular to the longitudinal axis of the tube to obtain convergence symmetry while the position of the first core portion remains the same. In this way, convergence symmetry adjustment is accomplished separately from image geometry adjustment.

Abstract: In a deflection yoke mounted on a cathode ray tube, a pair of silicon steel field harmonic enhancers are placed over rear portions of a horizontal deflection coil of a saddle coil type near an electron beam entrance region of the coils such that portions of the saddle coils are interposed between the field harmonic enhancers and a neck portion of the cathode ray tube. The field harmonic enhancers reduce horizontal coma error by making the horizontal deflection field in the rear portion of the saddle coils more pincushion shaped.

Abstract: This invention relates to a deflection arrangement for a video display of color pictures. The arrangement comprises a deflection yoke including a pair of vertical deflection coils toroidally wound on a magnetic core, using a multi-layer terminal technique. An R-C network is coupled between an intermediate terminal of the firstly wound layer of one of the coils and between an intermediate terminal of the firstly wound layer of the other one of the coils. The R-C network suppresses ringing in the coils that are produced by a horizontal deflection coil during horizontal retrace.

Abstract: The invention relates to a method for manufacturing a phosphor screen on an inner surface of a CRT panel, having a faceplate, a blend radius, and a sidewall. The method includes the steps of depositing at least one phosphor layer (R, G, B), containing a binder, on the inner surface of the faceplate, and then coating the phosphor layer, the blend radius, and at least a portion of the sidewall with a filming material. The coating of the filming material is dried to form a film. The film, or at least that portion thereof overlying the blend radius and the side wall, is contacted with an adhesion-promoting, blister-reducing solution which contains operable quantities of silica particles, a low vapor pressure alcohol and deionized water. A metal layer is deposited on the film, and the film and the binder contained in the phosphor layer are volatilized.

Abstract: A deflection yoke liner for mounting deflection coils on a cathode ray tube; the liner has at least two interconnectable sections with interengaging snap fasteners in the form of a tab and block that position and fix together the liner sections. The tab has a stop or hook adjacent a distal end for clasping over the block. The block has an inlet groove for guiding the tab and thereby positioning the liner sections relative to one another. One of the groove and tab tapers inwardly and the other is complementary and tapers outwardly. Preferably the tapering sections of the groove and tab engage near a point of full abutment of the liner sections, by way of tapered shoulders at the proximal end of the tab and a narrowing inlet taper on the block. The liner sections are positively positioned as the tab is advanced in the groove until the hook snaps over the abutment upon bringing together the liner sections. The block can be discrete or formed by a continuous ridge.

Abstract: The present invention relates to a method for making a viewing screen structure for a cathode-ray tube. The method includes the steps of coating a support surface with a film of a polymeric material, a suitable dichromate and a sensitizer therefor which is a chromium ion migration enhancer having a reduced sensitivity to thermal and dark hardening; exposing the film to an image in the form of radiant energy until the solubility of the irradiated regions thereof is selectively altered, thereby producing in the film regions of greater solubility and regions of lesser solubility; removing those regions of the film with greater solubility to bare portions of the underlying support surface while retaining those regions of the film with lesser solubility. The bare portions of the support surface and the retained film regions are overcoated with a composition of light-absorbing material which is adherent to the support surface.

Abstract: A device for the internal graphitization of the surface of the neck in the cone of cathode ray tubes.A device of this type comprises a frame bearing two arms, such as, capable of rotating around an axis, such as, each bearing a collar, for example, each adapted to a given type of cone. This collar has two functions: that of providing for centering along an axis (xx) of the neck of the cone and that of defining a reference line (L.sub.r).With these arms there cooperate, firstly, a supporting table on which the cone is laid and centered in a horizontal plane and, secondly, a graphitization system such that the brush in its top position reaches a determine upper limit (Lg) and, finally, a combination of means providing for the upward translational motion of the supporting table and of the graphitization system, the regulated descent of the latter, the supporting table remaining still during this stage of descent of the brush.

Abstract: The disclosure concerns the manufacture of mask type color television tubes. A diaphragm is used, for which the profile or aperture is modified during the operation for the uniform illumination of the vertical stripes of the screen during the different stages for the deposition of luminophors. The modification of the profile is obtained by the shifting of strips parallel to the vertical stripes.

Abstract: A method for the metallizing of a luminescent screen comprises the following steps:the depositing of at least one luminophor coat, comprising at least one binder, on the inner face of the screen;the depositing of a sub-layer, consisting of at least one aqueous emulsion of a water-insoluble film-forming resin;the drying of the sub-layer and the heating of this screen to a temperature greater than the minimum temperature for the formation of the film;the depositing of a finishing layer;the drying of the finishing layer;the depositing of a metallic coating on the finishing layer, and,the volatilizing of the binders of the luminiphor screen, the sub-layer and the finishing layer, wherein the sub-layer and the finishing layer are made from the same aqueous emulsions of water-insoluble film-forming resins, said emulsions having a film-forming temperature of below 45.degree. C. and giving a continuous, thin, resistant, reflective and hydrophobic film.

Abstract: Disclosed are a method for the fabrication of a color television tube as well as a front panel for trichromatic television tubes. The disclosure can be applied to the reception of high-definition television transmissions. According to the disclosure, the front panels designed for a high-definition television tube screen are elements of the group of surfaces defined byZ=.SIGMA.(C(i).multidot.x.sup.j(i) .multidot.y.sup.k(i)Z(i)=Co(i).multidot.F.sup.-(j(i)+k(i)-1)100.multidot.ABS(Zn-Z)<5.multidot.Zdwhere Z is the dimension of a surface of the group, Zn the dimension of a test surface and Zd the dimension of the maximum value of the dimension of the surface. Co corresponds to a reference surface of the group.

Abstract: The grip disclosed has a rotationally driven, threaded rod, with one part having a left-hand pitch while the other part has a right-hand pitch. The rod driving, by means of nuts and connection rods, has gripping arms that apply balanced forces to the object to be grasped. The arms and the threaded rod are floating with respect to the casing of the clamp, but can be locked as soon as the part is grasped.

Abstract: A method for the metallization of a luminescent screen comprises the following steps:the depositing, in a known way, of a layer of at least one luminophor containing, among others, a binder on a transparent face panel;the depositing, on said layer, of a sub-layer consisting of an aqueous emulsion of a water-insoluble resin, the emulsion being neutral or alkaline and being capable of forming a hydrophobic film;the drying of the sub-layer;the depositing, on said sub-layer, of a coating consisting of an aqueous emulsion of a water-insoluble film-forming resin, said emulsion containing 0.1% to 4.0% by weight of hydrogen peroxide, 0.25% to 2.5% by weight of a water-soluble polymer and 0.1% to 1.0% by weight of colloidal silica,the drying of the coating;the depositing of a metallic layer, andthe volatilizing of the binder, the sub-layer and the coating.

Abstract: To improve the trichromatic cathode tube shielding effect given by the frame-mask set and by a shielding material made with material of low magnetic permeability, the external conductors of a de-magnetization coil with two loops are made to pass in front of the fastening lugs and not behind the frit plane as was the case before, and the position of the internal conductors is set to obtain the best compromise.

Abstract: For the automatic determining of the characteristics of the corrections to be made in trichromatic cathode tube deflectors, measurements are made of the coordinates of the midpoints of the bars R and B of a crossed bar test pattern at "strategic" places. With the deflector in the "mean" position on the tube, the values obtained are standardized by computation to re-establish virtually the ideal position of the deflector, the convergence errors due to this deflector are computed and the pinpoint or overall corrections to be made to it are deduced therefrom.

Abstract: Disclosed is a device for holding a substantially parallelepiped-shaped part in position. This device has, fixed on a base, a supporting device on which the part rests and two supporting elements which clamp the part on two opposite sides. The two supporting elements are fixed to a deformable, quadrillateral element so that there is a continuously variable distance between the two supporting elements.

Abstract: Disclosed is a machine for the implanting of a cathode in an eyelet of a cathode-ray tube gun. This machine has a gun-supporting device which is movable along the axis of the gun, a cathode-supporting device positioning the cathode along the axis of the gun and a sensor with retractile rod which works together with a first detector, giving the position of the cathode when the rod rests on the grid G1, said sensor being capable of being shifted in a direction perpendicular to the axis of the gun. It further has a gauge rod, with a calibrated length, which rests on the grid G2 and ends at the side opposite to the eyelet, with a second detector recording the position of the gauge rod and a control device determining the shift of the gun-supporting device on the basis of the measurements made by the two detectors.

Abstract: A method is disclosed for the setting of the static convergence and/or purity of a color television tube using permanent magnets. Magnetizable elements are fixed around the color television tube. These elements are evenly distributed around the axis of the tube. To correct the static convergence and/or purity errors, each element is magnetized by means of a corresponding coil, the position and dimensions of which are such that the element is subjected solely to the field within the turns of the coil.

Abstract: A method for the mounting of a shadow mask in a trichromatic cathode tube pertains especially to the mounting of the mask on a frame. The shadow mask has a perforated, plane active surface which must be held under sufficient mechanical tension, so that it preserves its planarity during the functioning of the tube. The method consists in increasing the dimensions of the active surface, either by heating it to expand it or by stretching it mechanically to give it the desired mechanical tension, and then in soldering the mask to a sufficiently rigid frame to maintain the active surface in its state of mechanical tension.

Abstract: The cathode-inserting machine of the invention has a gun carriage, movable between two stops under the effect of a jack, a retractable sensor and a cathode support. The overall length of the sensor is equal to the travel of the carriage. It is thus enough to measure the distance between the sensor and the cathode when the carriage is at the rear stop and then to move it forward to the front stop in order to position the cathode exactly in its eyelet.

Abstract: A method of manufacturing stems for vacuum tubes is disclosed. The method makes it possible, in particular, to improve the quality of the seal between the metallic bushings and the glass of the stem. The method consists in loading a bottom mold with a first glass piece and a second glass piece and metallic conductors, and then in heating the glass pieces before pressing them against each other between the bottom mold and the top mold. According to one characteristic of the invention, the first piece, which constitutes an external piece partially fixed in the bottom mold, is directly heated only on an upper part which is not fixed, and the two glass pieces are pressed against each other as soon as the upper part has reached a so-called working temperature in order to prevent prolonged contact between the upper part and a limited surface of the conductors.