Abstract: A shadow mask includes an aperture area having a plurality of apertures through which electron beams pass; a non-aperture area extending a from a circumference of the aperture area; and a skirt formed extending from an outer circumference of the non-aperture area at a predetermined angle, wherein the front surface of the aperture area is formed satisfying the following conditions, 100%<RMV?/RMV<110% 120%<RMS/RMV?<150% where RMV is a vertical radius of curvature of the front surface of the aperture area with respect to a vertical direction passing through a center of the aperture area, RMS is a vertical radius of curvature with respect to a short side of the aperture area, and RMV? is a vertical radius of curvature of the front surface of the aperture area with respect to the vertical direction at a location on a horizontal axis passing through the center of the aperture area.

Abstract: The invention relates to an inner shield for color cathode ray tube. The inner shield has two long side parts and two short side parts. Each of two long sides has an opening part which comprises an inclined part and an U-shape recessed edge. Otherwise, the opening part may comprise an vertical part and an U-shape recessed edge. Each of two short sides has a V-shaped opening. The inner shield of the invention is capable of surely shielding unintended external magnetic field.

Abstract: A mask-frame assembly for a color cathode-ray tube comprising a first and second support members spaced out a predetermined distance; first and second resilient support members installed between the first and second support members supporting the first and second support members, each at the first and second resilient support members comprising supports fixed to the first and second support members and a connecting portion connecting the supports; a mask installed at the first and second support members such that tension is applied thereto, the mask comprising a plurality of electron beam through holes; and a compensating unit connected between the first and second support members or the supports of the resilient support members between each connecting portion and the mask, the compensating unit being formed of a material having a lower thermal expansion coefficient than the first and second resilient support members.

Abstract: Color cathode-ray tube comprising a color selection mask tensioned in at least one direction, the mask having, on its peripheral area, mask-vibration damper means in the form of a coupled oscillator of the type comprising a metal strip whose ends are welded to the surface of the mask and whose central region comes into contact with the surface of the mask by a spring effect.

Abstract: A color picture tube includes: a glass panel having a substantially rectangular-frame skirt; a rectangular frame holding a shadow mask; and a support spring elastically supporting the frame inside the skirt and fixed to a first position at inside surface of a long side of the skirt and to a second position at the facing outside surface of the frame. The first and second positions are away in horizontal axis direction perpendicular to tube axis and substantially parallel to the long side. The second position is more away from vertical axis perpendicular to tube axis and horizontal axis than the first position. Materials for the support spring and frame are selected so that, in horizontal axis direction, thermal expansion amount of the support spring between the first and second positions is substantially same as that of the frame between the second position and vertical axis when the tube is operated.

Abstract: A cathode ray tube comprises a panel; a funnel engaged to the panel for forming a vacuous space; and a shadow mask supported in the cathode ray tube by being fixed to a mask frame and including an effective surface having a plurality of electron beam passing holes at a center thereof, an ineffective surface formed at a periphery of the effective surface and not having the electron beam passing holes and a skirt portion extended from the ineffective surface towards a vertical direction thereof and welded to the mask frame. In the cathode ray tube, a slot of a predetermined size is formed between welding points by which the skirt portion is welded to the mask frame, and a height of the slot from an end of the skirt portion is higher than a height of the welding points, thereby reducing a doming effect of the shadow mask, reducing a mis-landing which the electron beam does not land to a precise landing point, and thus preventing a color purity of a screen from being deteriorated.

Abstract: An apparatus and method for retaining a damper wire used in a cathode ray tube to reduce vibration in the grill type mask assembly of a cathode ray tube. The damper wire is retained across a grill type mask by a bimetal damper spring having a first end and an opposing second end. The second end is coupled to the frame of the grill type mask assembly. A tab located proximate the first end of the damper spring is adapted to accept the damper wire that traverses the mask.

Abstract: A structure of a slot feature for a shadow mask in which, on the assumption that the width at the point of ½ in a vertical direction in the feature of slots of the shadow mask is ‘Sw’, horizontal distances from a virtual vertical line passing an apex of a concave portion of a slot at a marginal portion to a protrusion portion formed at both upper and lower sides on the basis of the width Sw line are ‘M’ and ‘N’, and angles inclined in the direction of the protrusion portion from the virtual straight line passing the apex of the curved protrusion portion formed at the opposite side of the concave portion are ‘P’ and ‘Q’, there are at least one and more mask slot satisfying a formula of M>0, N>0, P>0°, Q>0°. The shape of electron beams by positions on the screen are identical to each other, and the shape of electron beam at the left and right sides of marginal portion can be maintained in a straight line in the vertical direction.

Abstract: A color cathode ray tube comprising a panel having a substantially flat outer surface, a funnel mounted on a rear side of the panel, a shadow mask including a plurality of electron beam through holes, and a mask frame for supporting the shadow mask, said mask frame satisfying the following condition: d/v?0.9, d/h?0.9 wherein d is a height of a center of a diagonal portion of the mask frame, h is a height of a center of a short side portion of the mask frame, and v is a height of a center of a long side portion of the mask frame.

Abstract: The present invention provides an improved support blade structure for use on a tension mask frame assembly. The support blade structure is formed of a material having a first coefficient of thermal expansion and includes fastening portions and an insert member connected at a generally central location to the support blade structure. The insert member is formed of a material having a second coefficient of thermal expansion and has a plurality of apertures extending in a row along its length. The aperatures are dimensioned to be larger than the fastening portions passing therethrough to loosely connect the insert member to the support blade structure. This allows the insert member to be connected at the center while it's end are free to slide relative to the support blade structure during thermal cycling.

Abstract: A cathode ray tube having a panel with a fluorescent film made of a fluorescent material coated at the inner surface thereof; a cathode mounted in the panel and generating an electron beam; an electron beam controller for controlling and deflecting the electron beam in order to hit the fluorescent film; and a back glass attached to the panel and sealed in a state that the cathode and the electron beam controller are mounted therein, in which a ratio of a minimum thickness of a panel glass to a minimum thickness of a skirt portion of the panel is below 1.0. The full depth of the cathode ray tube is reduced and the weight of the cathode ray tube is minimized by controlling the thickness of the panel glass, the skirt portion of the panel glass and the back glass. In addition, the atmospheric pressure applied to the panel glass and the back glass is uniformly distributed to the panel glass, the back glass and the skirt portion, thereby performing a deformation.

Abstract: The cathode-ray tube according to the present invention has on the inner surface of the funnel section of the body thereof a laminated layer comprising a first layer of black material, a metal backing layer and a second layer of black material. According to the configuration of the cathode-ray tube of the present invention, stray light reflected within the body of the cathode-ray tube is absorbed by the first layer of black material on the inner surface of the funnel, while stray light reflected off the inner surface of the funnel is absorbed by the second layer of black material. This makes it possible to reduce the amount of stray light incident upon the effective screen area of the panel section.

Abstract: A mask frame assembly in a cathode ray tube is capable of minimizing a howling phenomenon and preventing local wrinkles of a shadow mask by optimizing positioning of compression of the mask frame assembly. A mask frame assembly for applying optimal tension in a cathode ray tube includes a shadow mask for selecting color and a frame assembly having a main frame for applying tension to the shadow mask and a sub-frame for supporting the main frame, wherein each of compression points of the main frame is set to satisfy the following expressions, (L/2)×0.38?X1?(L/2)×0.52, and (L/2)×0.80?X2×(L/2)×0.98, where L is a length of a long side of the main frame, X1 and X2 are distances from the center of the main frame to each of compression points P1 and P2 in both sides.

Abstract: Positions of paired perforations that are provided in a shadow mask and through which a vibration suppressor is to be inserted with play are deviated from each other in a horizontal direction and in a vertical direction. Since the positions of the paired perforations are deviated from each other not only in the vertical direction but also in the horizontal direction, upon vibrations of the shadow mask, the vibration suppressor surely comes into contact with, rubs against, and separates from the periphery of both of the paired perforations. Consequently, a vibration attenuating effect by the vibration suppressor is exhibited stably, and a vibration decay time can be reduced.

Abstract: A cathode ray tube comprising a panel of which an outer surface is substantially flat and an inner surface has a certain curvature, and a shadow mask arranged with a certain interval from an inner surface of the panel and having a plurality of apertures through which electron beams pass, wherein the shadow mask satisfied a condition of 0.9≦ZmD/(ZmX+ZmY)≦1.1, in which an arbitrary point on a diagonal axis of the shadow mask is supposed to be Dr, points on a long axis and a short axis meeting with perpendiculars drawn to the long axis and the short axis from the point Dr are respectively supposed to be Xr and Yr, and intervals between the respective points Xr, Yr, and Dr and the shadow mask in a tube axis direction are respectively supposed to be ZmX, ZmY, and ZmD. In the cathode ray tube, a structural strength of the shadow mask is enhanced thus to increase an impact resistance of the shadow mask.

Abstract: A cathode ray tube comprises a panel having a fluorescent formed on an inner surface thereof; a funnel connected to the panel; an electron gun housed in the funnel emitting electron beams; a deflection yoke for deflecting the electron beams in horizontal and vertical directions; a shadow mask for selecting colors of the electron beams; and a mask frame for supporting the shadow mask, in which an outer surface of the panel is substantially flat and an inner surface has a designated curvature, and a radius of curvature from a center of the shadow mask in a major-axis, minor-axis and diagonal-axis direction is substantially same.

Abstract: A cathode ray tube including a tube realized through a face panel, a funnel, and a neck; a color selection apparatus including a shadow mask having a an effective area with apertures and a mask frame supporting the shadow mask; an electron gun mounted in the neck and emitting electron beams; a deflection apparatus generating a magnetic field to deflect the electron beams; and a moire compensation circuit performing moire compensation, wherein the color selection apparatus satisfies the following condition, 0.76 ≥ Ke Ko ≥ 0.

Abstract: A shadow mask for a color cathode-ray tube including a first portion on which a plurality of electron beam through holes are formed; and a second portion on which no electron beam through holes are formed, the second portion surrounding the first surface portion, wherein each of the plurality of electron beam through holes includes an electron beam exit hole, each of the electron beam exit holes of electron beam through holes formed at a periphery of the fist portion near the second portion having a first length Dh in a direction facing away from the center of the shadow mask that is greater than a second length Dv perpendicular to the direction facing away from the center of the shadow mask. Therefore, a vibration generated on the shadow mask is attenuated within an elastic range of shadow mask, and thereby the shadow mask is able to endure an external shock and a permanent distortion to the shadow mask can be prevented to ensure color purity of the color cathode-ray tube.

Abstract: A shadow mask is composed of a main mask and a sub-mask lapped on each other. Each smaller hole that opens in the main mask has a diameter gradually reduced toward each larger hole, and each smaller hole that opens in the sub-mask has a substantially fixed diameter or a diameter gradually increased toward each larger hole. In this configuration, no part of the smaller-hole-side surface of the sub-mask is hit by an electron beam, so that the electron beam is reflected by a sidewall surface of the main mask only. Thus, a satisfactory screen can be obtained without causing undesired distinctions in brightness or belt-shaped boundaries to appear on the display screen.

Abstract: A cathode ray tube is provided which includes a panel having a fluorescent surface formed on an inside surface thereof, a tension type shadow mask fitted to the panel with a gap formed therebetween, and a frame. The frame includes two main frames fixed to the tension type shadow mask under tension, and two subframes fixed respectively to ends of the two main frames. A distance between the two main frames between a center part or portion of the main frame and an edge part or portion. To assemble the frame assembly and the shadow mask, the main frames are compressed, the tension type shadow mask is welded thereto, and the compression applied to the main frames is then released. The invention improves a howling characteristic by reducing a vibratory length of the shadow mask and increasing a natural frequency of the center part or portion of the shadow mask.

Abstract: A cathode ray tube including a shadow mask which is composed of a effective portion having a plurality of holes through which an electron beam passes and a skirt portion extended approximately in a perpendicular direction to the effective portion, wherein a guiding notch is formed in the skirt portion, the guiding notch includes an end portion which is formed to be opened to the end of the skirt portion and a fixing portion to which a guiding means is fixed, and a width of the end portion is wider than the diameter of the fixing portion. Therefore, the doming effect of the shadow mask is reduced and performance of press processing of the shadow mask can be improved.

Abstract: A color cathode ray tube including a generally rectangular shadow mask having a curved aperture portion having a multiplicity of electron-transmissive apertures, a curved imperforate portion surrounding and integral with said apertured portion and a skirt portion being bent back from a periphery of said curved imperforate portion; said skirt portion being provided with a plurality of embossments and a plurality of: (a) tilted slits or (b) a plurality of tilted slits with bridge.

Abstract: A cathode ray tube comprising a panel having an outer surface which is substantially flat and an inner surface which has a radius of curvature, and a shadow mask having a plurality of apertures through which electron beams pass, wherein a ratio Sh/Sv of a horizontal dimension Sh of the aperture to a vertical dimension Sv of the aperture satisfies a condition of Sh/Sv<1 at a central portion of the shadow mask, and thereby improving strength of the shadow mask. Thusly, deformation of the shadow mask caused by an external impact or the like can be minimized, and a grade of color purity of a screen can be maintained optimally.

Abstract: The invention relates to a magnetostriction control alloy sheet advantageously used as a high resolution shadow mask having a low coefficient of thermal expansion, superior magnetic properties and a high Young's modulus after a blackening process, a manufacturing process for the same, and a part for a color Braun tube such as a shadow mask. The magnetostriction control alloy sheet comprises C at 0.01 wt. % or less, Ni at 30 to 36 wt. %, Co at 1 to 5.0 wt. %, and Cr at 0.1 to 2 wt. %, the remainder Fe and unavoidable impurities, and having a magnetostriction &lgr; after the softening and annealing of (−15×10−6) to (25×10−6).

Abstract: A color cathode-ray tube includes a shadow mask (20) stretched and held with tension applied thereto in one direction. The shadow mask is made of an Invar material. A stress generated in the shadow mask by the tension is 32 MPa or more in a range of ±20 mm with respect to a center position of the shadow mask in a direction orthogonal to a direction in which the tension is applied, and is 26 MPa or more outside the range. By stretching the shadow mask under this stress condition, magnetic shield characteristics are enhanced, and mislanding of an electron beam can be reduced. As a result, a satisfactory color image display can be obtained.

Abstract: A color selection apparatus for a cathode ray tube. A mask is formed having a long axis and a short axis. A frame supports the mask in one of a long axis direction and a short axis direction. The mask has a plurality of strips separated by a predetermined distance. A plurality of first beam apertures are formed as single long slits between the strips in a center portion of the mask. A plurality of second beam apertures are formed on outer portions of the mask to both sides of the center portion of the mask. The second beam apertures are divided into a plurality of individual units within a single column by real bridges and at least one dummy bridge for each individual second beam aperture unit. The at least on dummy bridge extends inwardly from the strips but does not cross completely through the individual second beam aperture unit.

Abstract: A tension mask cathode ray tube has a vacuum tube and an inner shield mounted within the vacuum tube to shield the vacuum tube from geomagnetism. A value Br/Hc of the inner shield where Br indicates a residual magnetic flux density and Hc indicates a coercive force is established to be 1.0-2.0 times more than a value Br/Hc of the mask frame. In this structure, the route of electron beams is established to be more precise. Consequently, the purity characteristic and the convergence characteristic are improved while forming a precise raster. In this way, the display screen quality can be enhanced.

Abstract: Disclosed is a CRT(Cathode Ray Tube), in which lengths of vertical axes(Y-axes) of outermost row slots of a long side of a shadow mask, slots adjacent to the outermost row slots in a central direction of the shadow mask and slots adjacent to the adjacent slots in a central direction of the shadow mask are maintained in the range of 70%˜110% of a length of a vertical axis (Y-axis) of a perfect slot, thereby providing a visually stable screen.

Abstract: A display arrangement includes a cathode ray tube, inside which tube a mask with at least one curved outer edge is located. The mask is at least partly attached by at least part of the curved edge to the tube by means of at least a diaphragm arrangement. The diaphragm arrangement includes at least one diaphragm part in the form of an elongated folded sheet including a straight fold, said sheet extending from the straight fold to a curved fold and from the curved fold to a curved part of the sheet for attaching to the curved mask edge. Preferably, the straight fold has a varying folding angle and the curved fold follows a curve which enables the transition from the straight fold to the curved fold to provide a folded sheet which is free from inherent mechanical stress.

Abstract: In a mask assembly for a color cathode ray tube, the color selection mask has the form of a thin metal plate with relatively long vertical slits alternating with vertical columns of relatively short slots, at least in the central screen area. The metal strips bounding a column of slots are joined by real bridges, which define the slots. Dummy bridges project from the metal strips into the slits, to reduce the electron beam flux transmitted through the slits to approximately the same level as the electron beam flux transmitted through the columns of slots, thereby preventing brightness irregularities on the screen. The alternate arrangement of slits and columns of slots also reduces vibration and prevents doming.

Abstract: A mask structure for use in a color CRT includes a color-separating mask made of a thin metal plate having a row of slits formed therein with a predetermined pitch, and a mask frame holding the color-separating mask while applying tension perpendicular to a direction in which the slits are arranged to the color-separating mask. The color-separating mask has a first hole-bearing area including all of the slits of the row except two outermost slits of the row, and two second hole-bearing areas each of which includes one of the outermost slits. The thin metal plate has projections formed therein for each of the outermost slits, the projections protruding to an opening of corresponding one of the outermost slits. The opening area of the outermost slits of the second hole bearing areas is smaller than the opening area of the slits of the first hole bearing area.

Abstract: The disclosed device is directed towards a shadow mask for ion beams comprising a silicon wafer with a hole pattern arranged therein, wherein the silicon wafer is provided at a side confronting the incident ion beams with a metallic coating which stops the ion beams and dissipates heat, wherein an apertured region of the silicon wafer has a thickness from about 20 &mgr;m to about 200 &mgr;m and apertures in the shadow mask have lateral dimensions from about 0.5 &mgr;m to about 3 &mgr;m.

Abstract: In the structure of the present invention, there can be provided a cathode ray tube in which deviation in the trajectory of the electron beams by the leakage magnetic field from the mask frame (1) is decreased by using a polygonal mask frame (1) in which the relative magnetic permeability of longer side members (31) out of two side members adjacent to each other at the joint portion of the mask frame (1) is the same as or larger than the relative magnetic permeability of the other side members (21). Thus, the significance of the present invention in industrial terms is large.

Abstract: A shadow mask frame assembly of a flat cathode ray tube (CRT) includes a shadow mask including a plurality of strips formed at a main body in a vertical direction by being separated a predetermined distance by slits and a plurality of bridges forming slots by connecting neighboring strips and sectioning the slits, in which the slots include a first slot group including slots having a wide interval between the bridges and a second slot group including slots having a narrow interval between the bridges, first and second support members secured at a long side portion of the shadow mask, and a frame including first and second elastic members, either end portion of each of which is secured to each of the first and second support members, for applying a tension force to the shadow mask.

Abstract: A cathode ray tube includes an evacuated envelope having a substantially rectangular faceplate panel with two diagonal axes that extend between the opposing corners of the panel. The panel includes a mask-frame assembly having a frame with two opposing long sides and two opposing short sides forming a continuous mask support frame. The frame is mounted within the tube by brackets located near the corners of the frame. Each bracket is adjustably secured along the short sides of the frame and includes a flat surface section extending normal to the diagonal axes of the panel. A spring clip assembly is secured to the flat surface section of the bracket for engaging a stud affixed to the panel.

Abstract: A mask assembly is formed to have a tension mask with a screen part for transmitting electron beams. The mask assembly is intended for use with a cathode ray tube. The screen part includes real slots, dummy slots, real bridges, dummy bridges, and strip parts. The screen part has a first portion and a second portion. The first portion has real bridges, dummy bridges, and dummy slots. The second portion has real bridges and real slots, but no dummy bridges and no dummy slots. The second portion of the screen part can be said to be associated with a center region that traditionally has degraded images due to undesired black lines. The second portion of the screen part is formed to have real bridges, real slots, no dummy bridges, and no dummy slots in order to provide improved clarity. The mask assembly has a tension mask which extends in either a longitudinal or transverse direction, and a mask frame for reinforcing the structural strength while maintaining an extended state of the tension mask.

Abstract: A cathode ray tube includes a panel having a front screen portion on which a phosphor screen is formed and a panel flange integrally formed on an edge of the front screen portion, a funnel connected to the panel flange, a deflection yoke disposed around the funnel, a neck connected to the funnel, an electron gun disposed in the neck, a color selection apparatus for selecting electron beams emitted from the electron gun and allowing the selected electron beams to land on corresponding phosphors, and an inner shield for shielding geomagnetism, the inner shield mounted on the color selection apparatus. The color selection apparatus includes a mask having a plurality of electron beam-passing apertures, the mask being rectangular and having a longitudinal axis and a lateral axis, a frame for supporting the mask in a tensioned state, and a pair of side shield members mounted on lateral sides of the frame to shield the geomagnetism.

Abstract: This invention provides a mask frame for a color CRT made from a steel composition consisting essentially of, in mass %, C: 0.03-0.30%, Si: at most 0.30%, Mn: 0.05-1.5%, P: at most 0.05%, S: at most 0.02%, Mo: 0.02-0.50%, V: 0.02-0.20%, Al: at most 0.10%, N: 0.0040-0.0200%, Cu: at most 1.0%, Ni: at most 1.0%, Cr: at most 2.0%, W: at most 1.0%, B: at most 0.003%, Ti: at most 0.030%, and Nb: at most 0.030%, and a balance of iron and unavoidable impurities, with Al≦(7.0)N, and having a metal structure in which the ferrite grain size is at most 15 micrometers and the ferrite volume ratio is at most 90%.

Abstract: Shadow mask in a color cathode ray tube, including a plurality of slots for passing electron beams, and an open type bridge having a portion removed therefrom and dividing into slots in a vertical direction, wherein a difference ‘Ti’ of horizontal distances of an electron beam inlet edge and an electron beam outlet edge of the open type bridge formed near to vertical center line ‘l’ of the shadow mask is equal to, or greater than a difference ‘To’ of horizontal distances of an electron beam inlet edge and an electron beam outlet edge of the open type bridge formed far from a vertical center line ‘l’ of the shadow mask, thereby enhancing a luminance while open type bridges having an advantage over doming are maintained, and quality deterioration caused by view of bridge shadows coming from lengthened slots with a reduced number of bridges can be overcome.

Abstract: In a mask frame for a cathode ray tube in accordance with the present invention, by satisfying 0.80≦a/(Xd/4)+b/(Yd/4)+c/(Dd/4)≦1.25, herein, Xd is a long side length of the mask frame, Yd is a short side length thereof, Dd is a diagonal length thereof, a is a height of the center of the long side thereof, b is a height of the center of the short side thereof, and c is a height of the corner portion, assembly can be facilitated, howling and drop characteristics can be improved, a width of a panel can be reduced, and accordingly the cathode ray tube can be slimed down and light-weighted.

Abstract: A color cathode ray tube has stress-absorbing hole patterns in skirt portions of its color selection electrode. Each of the stress-absorbing hole patterns is composed of a plurality of columns of rectangular through holes, and the columns are arranged in a lengthwise direction of the skirt portions. Each of the plurality of columns of rectangular through holes is composed of rectangular through holes arranged in a widthwise direction of the skirt portions. The relationships in shape of the rectangular through holes among outermost columns, columns next to the outermost columns, and remaining columns is optimized in the stress-absorbing hole patterns.

Abstract: The present invention relates to a colour picture tube and to a manufacturing method for a colour picture tube. The colour picture tube includes a shadow mask which is secured to a mask frame. In order to improve the shielding effect, a shielding plate, which shields external magnetic fields, is secured to at least one longitudinal bar of the mask frame. By means of such a shielding plate, the picture quality of a colour picture tube can be improved and the manufacturing efforts can be simplified in comparison with conventional colour picture tubes.

Abstract: A shadow mask includes a shadow mask body opposed to a phosphor screen, and its peripheral portion is fixed to a mask frame. The shadow mask body includes a rectangular effective portion that is formed having a large number of electron beam passage apertures. The effective portion has a major axis and a minor axis that pass through its center and extends at right angles to each other. The shadow mask comprises an auxiliary mask fixed to a region that contains the minor axis of the effective portion of the shadow mask body. The auxiliary mask is in the form of a strip that extends long in the direction of the minor axis and has a large number of electron beam passage apertures that communicate individually with the electron beam passage apertures of the effective portion.

Abstract: A mask assembly for a color cathode ray tube, has an amount of tension applied to a shadow mask thereof reduced by preventing a main frame for applying tension in the shadow mask from deformation due to creeping during a high temperature process, by regulating the ratios of thickness, width, and height of the main frame to the thickness of the shadow mask. The color cathode ray tube comprises a frame composed of a main frame welded to the shadow mask for supporting the shadow mask toward the panel and a sub-frame supporting said main frame, wherein relations T/t≧45, W/t≧270, and H/t≧270 are satisfied, where t is a thickness of the shadow mask, T is the thickness of part where a main frame is welded to a shadow mask, W is a width of part attached to a sub-frame of a frame, and H is a length of main frame from said shadow mask to the sub-frame.

Abstract: A shadow mask with a slot having a substantially rectangular shape and a curved slot. The rectangular slot is composed of a back side opening formed on an electron beam incident side, a front side opening having a large area to allow the electron beam to pass, and a side wall sections inclining between the back side opening and the front side opening. The curved slot is composed of a back side opening (11) formed on the electron beam incident side and curved such that both longitudinal end portions are apart from an axis of ordinate passing a central portion of the shadow mask, a front side opening (2) formed having a large area to allow the electron beam to pass and side wall section (3 - - - 6) inclining between the back side opening and the front side opening.

Abstract: A material for shadow mask having the following composition of components: C≦0.0008 wt %, Si≦0.03 wt %, Mn:0.1 to 0.5 wt %, P≦0.02 wt %, S≦0.02 wt %, Al:0.01 to 0.07 wt %, N≦0.0030 wt %, B: an amount satisfying the formula: 5 ppm≦B-11/14×N≦30 ppm, balance: Fe and inevitable impurities; a method for producing the material; a shadow mask using the material (cold rolled steel sheet); and an image receiving tube equipped with the shadow mask. The material has excellent etching characteristics, which are uniform within the same coil, and excellent press formability.

Abstract: A mask for a color cathode ray tube (CRT) and a manufacturing method thereof are provided. This mask includes a plurality of strips isolated from each other at predetermined intervals in parallel, and a plurality of bridges for forming slots through which electron beams pass by connecting adjacent strips to each other. In this mask, each of the bridges between adjacent strips has a first curved portion formed on the side from which electron beams come out, and a second curved portion formed on the side upon which electron beams are incident. The first curved portion has a first width in the direction perpendicular to the length direction of the strips, and extends in the length direction of the strips. The second curved portion has a second width that is smaller than the first width in the length direction of the adjacent strips.

Abstract: In a shadow mask (7) for a color cathode ray tube, there are a region (23) having only dummy bridges (21), and a mixed region (24) having the dummy bridges (21) and real bridges (22). A dummy bridge size in the region (23) having only the dummy bridges (21) is greater than a dummy bridge size in the mixed region (24) having the dummy bridges (21) and the real bridges (22). The vertical size of the region (23) having only the dummy bridges (21) is greater than 50 percent of the vertical size of the shadow mask.

Abstract: A strip-type mask assembly includes a strip-type mask having slits and strips. The strip-type mask further has perforations aligned with at least one of the slits and is disposed in at least one of regions between the extreme ends of the slits and the weld lines. The distance between the perforation and the extreme end of the slit is less than or equal to 2 mm. The dimensions and the positions of the perforations, and the number of the perforations aligned with one slit are determined so as to reduce the difference among the widths of the slits resulting from the local variation of the distribution of the tension on the slits or the difference among the lengths of the slits.

Abstract: A shadow mask has a main mask and an auxiliary mask overlapped on the main mask. Electron beam passage apertures formed in the main mask and the auxiliary mask are arranged at given pitches in the direction of a major axis. Each electron beam passage aperture of the auxiliary mask is a communicating hole, which is formed of a smaller hole in that surface of the auxiliary mask which is in contact with the main mask and a larger hole opening in the opposite surface of the auxiliary mask. The smaller and larger holes of each electron beam passage aperture of the auxiliary mask have their respective central axes extending coaxially with each other and substantially at right angles to the surface of the auxiliary mask in the direction of the major axis.