Abstract: A cathode ray tube is provided, in which the flatness of a tension mask constituting a color-selection mechanism is maintained by a suitable stretching force, while with the tension mask, the influence of external magnetic fields, such as the terrestrial magnetism is suppressed, and the shifting of the electron beam is reduced. A tension mask made of a magnetostrictive material is used, the tension mask is stretched by a stretching force in a range maintaining the flatness of the tension mask, and the direction and strength of the stretching force are set such that vertical magnetic permeability of the tension mask increases, due to a magnetoelastic effect caused by the stretching force in the magnetostrictive material of the tension mask.

Abstract: An apparatus for maintaining tension in a mask frame of a cathode ray tube. The apparatus includes affixing a shadow mask to a pair of triboxes disposed along opposite sides of a mask frame at a predetermined tension. The triboxes are coupled to the mask frame by braces having a different coefficient of thermal expansion than the triboxes so as to compensate for the expansion of the frame during thermal cycling of the cathode ray tube. Consequently, it is possible to maintain the tension force applied to the shadow mask by the mask frame.

Abstract: A tension mask frame assembly for a color cathode-ray tube, including a tension mask, a frame and a vibration prevention unit, is provided. In this tension mask frame assembly, the tension mask has a slotted portion in which a plurality of electron beam passing holes are formed and a non-slotted portion located on the edge of the slotted portion. The frame supports two facing sides of the tension mask to apply a tensile force to the tension mask. The vibration prevention unit includes a damper having first and second attenuation portions that are maintained at a predetermined angle to form an insertion portion into which the edges of the tension mask not supported by the frame are inserted, and a support member for suspending the damper from the edges of the tension mask by passing through the first and second attenuation portions and the edges of the tension mask inserted into the insertion portion formed by the first and second attenuation portions.

Abstract: A structure for preventing howling of a shadow mask in a cathode ray tube. The tube includes a panel having a fluorescent material screen on an inside surface, a shadow mask for selecting a color of electron beams emitted from an electron gun, and frames each fastened to a long side of the shadow mask to support the shadow mask on the panel through connecting members for applying a tension to the shadow mask in a vertical direction. The shadow mask includes an effective surface having holes for selecting the color of the electron beams, non-effective surfaces which form no screen, and howling prevention members bent along short side edges of the non-effective surfaces in a horizontal front-to-back direction. This provides a high quality picture because howling is improved even at edge portions of the shadow mask owing to the enhanced moment of inertia and higher natural frequency of the edge portions of the shadow mask.

Abstract: A color cathode ray tube comprises a panel which outside surface is flat and inside surface has curvature, and a pressed shadow mask having a curved surface opposed to the panel inside surface. The curved surface of the shadow mask is such that the radius of curvature decreases approximately linearly as the position moves from the center to the periphery. Radii of curvature on the major axis, minor axis, and diagonal axis at positions having the same distance from the shadow mask center do not have large differences. This configuration can increase the mechanical strength of the shadow mask.

Abstract: A color cathode ray tube having a striped phosphor screen is provided, in which color displacements due to the tube axis (Z-axis) component of the terrestrial magnetism can be decreased at low cost. A positive temperature coefficient thermistor and a degaussing coil are connected in series to an AC power source (AC 100V) via a switch. A rectifier/smoothing circuit is provided in parallel to the positive temperature coefficient thermistor. When the switch is turned on, an ordinary degaussing process due to the AC attenuating magnetic field interlinked to the degaussing coil is performed, and the DC magnetic field in the Y-axis direction interlinked to the degaussing coil decreases the influence of the terrestrial magnetism in the tube axis direction (Z-axis direction).

Abstract: A color CRT includes a panel having a fluorescent film formed on an inner surface, a tension mask frame assembly installed in the panel and including a frame including a pair of first and second support members separated a predetermined distance from each other, and first and second elastic members installed between the first and second support members to support the first and second support members and having support portions fixed at the first and second support members and a connection portion to connect the support portions, a mask having electron beam passing holes formed therein and installed such that a tension is applied to the first and second support members, and a correction unit installed at the first and second support members or support portions between the connection portion and the mask, to correct a mis-landing of an electron beam due to thermal expansion of the mask and the frame.

Abstract: A purpose of the present invention is to provide material of an aperture grille used for a color picture tube having excellent yield strength, excellent high temperature creep strength and excellent magnetic characteristic, material of an aperture grille used for a color picture tube for improving an occurrence of cracking during a hot rolling step, a method for producing these material, an aperture grille and a color picture tube with the aperture grille. After adding nickel of 0.01 to 1.75 wt % to low carbon alloy steel including copper of 0.05 to 2.5 wt % and phosphor of 0.001 to 0.4 wt %, material according to the present invention is cold rolled. Then, a precipitation treatment is processed at a temperature of 300 to 700° C. Alternatively, the material is cold rolled and secondary rolled after passing through an intermediate annealing at a temperature of 500 to 800° C. Then, the precipitation treatment is processed.

Abstract: In a flat type color cathode ray tube, in using of a tint or a dark tint panel capable of improving contrast characteristics of a screen and reducing production processes, namely, having the conventional coating process reduction advantage, by optimizing a horizontal pitch and a transmissivity of a shadow mask and a transmissivity of a screen in order to solve a brightness balance deterioration problem at the circumference portion of the screen due to a glass transmissivity difference, it is possible to maintain inner impact resistance and howling characteristics of the shadow mask, in addition, by improving a circumference portion transmissivity of the shadow mask and a screen transmissivity, it is possible to improve a brightness balance at the circumference portion and a quality of the screen.

Abstract: The present invention provides a focus mask and frame assembly for a cathode ray tube. The cathode ray tube includes an evacuated envelope enclosing a luminescent screen, a focus mask, and a support frame having at least two long sides for supporting the focus mask between the electron gun and the screen within the cathode ray tube. The focus mask has an active array area formed of a plurality of strands and cross wires separated by an insulating material and defining a plurality of focusing apertures within the array area. A border is attached to the strands opposite the insulating material along the upper and lower outer edges of the active array area. The borders extend into the active array area such that the cross wires overlie a portion of the borders and the borders form focusing apertures with the strands along the upper and lower edges of the array.

Abstract: Frame assembly of a shadow mask in a flat Braun tube, in which a stress on a shadow mask is reduced for minimizing creep during an elevated temperature process, and a low tension on the shadow mask is corrected effectively during operation of a flat Braun tube after the elevated temperature process, for preventing deterioration of a color purity caused by deterioration of howling and doming, including a main frame fitted to the shadow mask, sub-frames connected between both ends of the main frame, and a thermal compensating plate fitted to a bottom of the sub-frames, wherein, first, a ratio(h/t) of a height ‘h’ of the sub-frame to a thickness ‘t’ of the thermal compensating plate is within a range of 4˜8, second, a ratio(b/b′) of a width ‘b’ of the sub-frame to a width ‘b′’ of the thermal compensating plate is within a range of 0.8˜1.

Abstract: A cathode ray tube comprising a color selection mask made from a material in tension and having a relatively low coefficient of thermal expansion, supported by a frame made from a material having a higher coefficient of thermal expansion. Along at least two sides of the frame are disposed two metal inserts made from a material whose coefficient of thermal expansion is similar to that of the mask. The inserts are secured to the opposed sides of the frame at their middle, and the mask is welded to the inserts. The mechanical problems relating to the differences in expansion of the materials making up the mask and the frame, during the high-temperature tube manufacturing steps, are avoided.

Abstract: A color CRT having an inner shield being mounted at a frame inside a panel and a funnel to shield an earth magnetic field, in which the inner shield comprises: a vertical portion formed in parallel to the central axis of the CRT and mounted at the frame, a slope portion extended slanted against the central axis of the CRT at a rear side of the vertical portion and a notch with its central portion formed concave at the end portion of the slope portion, the opposite of the frame; and on the assumption that the entire height of the inner shield constructed with the vertical portion and the slope portion is ‘V’, a height (V1) of the vertical portion satisfies the relational expression of 0.18≦V1/V≦0.25, and on the assumption that the shortest height from a starting point of the vertical portion to the notch is V2, the height V1 of the vertical portion satisfies a relational expression of 0.40≦V1/V2≦0.54.

Abstract: A flat cathode ray tube is provided. The flat cathode ray tube includes a shadow mask having a plurality of electron beam holes, a shadow mask frame having multiple-layered support members continuously connected, for supporting the shadow mask, and an inner shield connected to the shadow mask frame. The support member for supporting a shadow mask is solidified by forming multiple-layer laminates. Also, mobility is provided to the longer sides of the shadow mask, thereby easily applying a tension to the shadow mask.

Abstract: A cathode ray tube capable of reducing the doming amount and suppressing the occurrence of moire stripes at the same time with improved effects to suppress the occurrence of moire stripes even more is provided. The protruding portions 28a, 28b are protruding from the ends of the horizontal direction of the aperture to the inside of the aperture 27. With regard to the horizontal cross sections of the protruding portions 28a, 28b, the portions facing each other left and right via the aperture are formed to be asymmetrical to the center line 29 in order to reduce or block the incident electron beam. By forming the protruding portions 28a, 28b, the doming amount can be reduced and the occurrence of moire stripes can be suppressed at the same time. Furthermore, by forming the portions facing each other left and right of the protruding portions asymmetrically, the effects to suppress the occurrence of moire stripes can be improved even more.

Abstract: In a shadow mask for a color cathode ray tube including a plurality of slots in which electron beams pass, a roughly rectangular-shaped effective surface having long sides and short sides and a skirt portion downwardly curved-extended from the outer surface of the effective surface, wherein a horizontal pitch at the central portion of a shadow mask satisfies a condition of W×0.08%≦Pho≦W×0.086% when a horizontal pitch at the central portion of a shadow mask slot is Pho, a screen effective surface long side length is W and the shadow mask central portion is placed on the center in which the shadow mask effective surface long side is divided into three equal parts. In addition, the shadow mask satisfies a condition of Pho×0.24≦Sw≦Pho×0.30 when a slot horizontal width at the shadow mask central portion is Sw.

Abstract: Structure for supporting a shadow mask in a color cathode ray tube including main frames each extended along a long side having the shadow mask welded thereto directly, subframes each extended along a short side connected to the main frames for supporting the main frame, plate type supporting members each fitted to a position of an outer surface of respective frames, and elastic members having one side coupled to a stud pin on an inside surface of the panel, and the other side fitted to the supporting member, wherein the supporting member of the subframe includes a first and a second flanges opposite to each other extended downward vertically, and a parallel part extended horizontally between the first and second flanges, thereby maintaining a uniformity of welding quality during cathode ray tube fabrication and preventing color distortion during operation of the cathode ray tube.

Abstract: A color cathode ray tube has a color selection electrode structure made by stretching and welding a color selection electrode having a plurality of apertures to a frame while applying tension in the minor axis direction. A non-perforated region gradually becomes wider from a center portion to both end portions in the minor axis direction. Thus, sufficient tension is applied in the peripheral portion of the perforated region in the major axis direction of the color selection electrode, so that vibrations do not occur easily and the color selection electrode does not warp. Therefore, a color cathode ray tube with excellent color purity can be obtained.

Abstract: Shadow mask in a flat cathode ray tube having a damping wire fastened across a no-hole region between adjacent lines of beam pass through holes formed on a vertical line in the shadow mask for damping vibration of the shadow mask, including means for limiting a position of the damping wire on the no-hole region of the shadow mask, thereby enhancing a damping effect to improve a picture quality, and permitting to simplify a fabrication process and cut down a production cost.

Abstract: The invention provides a tension mask support frame assembly having a pair of support blade members attached to a frame. The support blade members are attached to opposite sides of the frame at a central location whereby each support blade member has a pair of distal ends extending from the central attachment point. A damping scrubber is disposed in the space between the support blade member and the frame near a distal end of the support blade members. Vibrations in the tension mask are thereby reduced through the transfer of the vibrations to the frame through rubbing action of the damping scrubbers.

Abstract: A cathode ray tube including a pair of supports arranged in parallel facing each other and a shadow mask acting as a color selection electrode including a large number of apertures. The shadow mask is stretched and held by the supports in a state in which tension is applied by the supports. In the shadow mask before being stretched onto the supports, the shapes of the apertures are varied so that the width of the apertures in the middle portion in the direction in which tension is to be applied narrows gradually from the central portion towards the both end portions in the direction parallel to the longitudinal direction of the support. Thereby, the shapes of the apertures can be made to be uniform over the entire surface in a state in which the shadow mask is stretched. As a result, a cathode ray tube with less color unevenness can be provided.

Abstract: A cathode ray tube has a tensioned mask supported by a support frame. The tension mask being susceptible to vibration and adapted for mounting in tension within the cathode ray tube. The tension mask includes damper wire support springs attached to, and extending from, opposite sides of the tension mask support frame. The damper wire support springs having a compliance section supporting a damper wire in contact with and across the surface of the tension mask for damping vibrations in the mask.

Abstract: A cathode ray tube capable of reducing the doming amount and suppressing the occurrence of moire stripes at the same time, which also can prevent the so-called persimmon stone phenomenon from occurring, is provided. In the apertures, the protruding portions that are protruding from end faces in the horizontal direction of the apertures to the inside of the apertures are formed. The protruding portion in the aperture located on the right side of the phosphor surface from the vertical center line of the shadow mask is protruding in the direction toward the peripheral portion on the right side, while the protruding portion in the aperture located on the left side of the phosphor surface is protruding toward the peripheral portion on the left side.

Abstract: A method of making a steel sheet for a tension mask, including the steps of: hot rolling a steel consisting essentially of, by weight %, C: less than 0.1%, Si: 0.05% or less, Mn: 0.4 to 2%, P: 0.03% or less, S: 0.03% or less, sol.Al: 0.01% or less, N: 0.010% or more, and the balance of Fe; and annealing the cold rolled steel sheet, followed by a secondary cold rolling at a reduction rate of 35% or higher. The steel sheet produced by this method shows excellent creep resistance during blackening treatment and excellent magnetic shielding property with an anhysteretic permeability of 3400 or more at a DC bias magnetic field of 0.35 Oe, and therefore causes no color-deviation when applied to the tension mask.

Abstract: A cathode ray tube has a tensioned mask supported by a support frame. The tension mask being susceptible to vibration and adapted for mounting in tension within the cathode ray tube. The tension mask includes damper wire support springs attached to, and extending from, opposite sides of the tension mask support frame. The damper wire support springs having a compliance section supporting a damper wire in contact with and across the surface of the tension mask for damping vibrations in the mask.

Abstract: A shadow mask includes a mask body having a principal mask surface with electron beam passage apertures, a skirt portion, and long and short axes, and a mask frame attached to outside the skirt portion. The mask frame has a coefficient of thermal expansion higher than that of the mask body. The skirt portion includes first and second tongue portions situated on the short and long axes, respectively. Each of the first and second tongue portions is fixed to the mask frame. The mask body is formed to fulfill relations given by (Ca·Wb)<(Cb·Wa), and V<H, where Ca and Wa are the length and width of the first tongue portion, respectively, Cb and Wb are the length and width of the second tongue portion, respectively, H and V are the length of the principal mask surface in the directions of the long and short axes, respectively.

Abstract: The CRT has a tensioned shadow mask with between 160-180 or between 210 and 240 slits per row and display devices having such CRT's. The first embodiment is in particular suited for CRT''s having a screen size larger than 21″ and for TVT applications, giving a substantially Moire free image for an NTSC, PAL and VGA signal, the second embodiment is in particular suited for CRT's having a screen size of 23″ or smaller and for CMT applications, giving a substantially Moire free image for a SVGA and XGA signal.

Abstract: A flat-type cathode ray tube which improves the brightness and color purity of a picture by improving a curvature of an inner surface of a panel of the cathode ray tube thereby preventing the mislanding of the electron beam, doming, howling, errors due to the magnetic field of the earth magnetism, and the like. The flat-type cathode ray tube includes a panel for displaying a picture, the outer surface of the panel is planar with an inner surface having inner surface curvatures, respectively, along the vertical axis direction and the horizontal axis direction.

Abstract: A shadow mask is composed of an iron-based alloy plate containing 31.0-38.0 weight % of nickel and 1.0-6.5 weight % of cobalt. The iron-based alloy has a crystal grain size number of 10 or more and 12 or less, has a crystal grain size of 50 &mgr;m or less in a cross section in a direction parallel and normal to a rolling direction of the iron-based alloy plate, and has an average crystal grain size of 30 &mgr;m or less in a cross section in a direction parallel to the rolling direction of the iron-based alloy plate.

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: Color CRT having a rectangular panel with an outer surface with a radius of curvature greater than 30,000 mm, an inner surface with a fixed curvature, and a skirt extended substantially perpendicular to the inner and outer surfaces, and a funnel connected to a skirt seal edge part of the panel, to meet conditions of 0.18≦OAH/(USD/2)≦0.

Abstract: A color display tube (1) is disclosed with an improved suspension of the color selection electrode (12). In order to have a color display tube with good properties of, for instance, color purity, it is of eminent importance that the color selection electrode (12) has and excellent positional stability. Especially wide screen tubes seem to be more sensitive to external shocks by which the color selection electrode (12) may shift and cause discolorations. The positional stability of the color selection electrode (12) can be improved by decreasing the friction between the color selection electrode (12) and the supporting elements (17) in the display window (3) of the color display tube (1). This is achieved by applying a supporting element (17) with a free end portion (22) having a small diameter and by applying a low force between the suspension means (20) and the supporting elements (17).

Abstract: In a color cathode-ray tube with a shadow mask stretched and held by supporters while being provided with a tensile force, a member with a substantially L-shaped cross-section is used for each of the supporters, which is obtained by forming of a strip plate material having a middle part and thinner thickness-deviation portions on both sides of the middle part by rolling of a metal material; and then bending and deforming of the strip plate material in its width direction by roll forming to form a bent and deformed portion in the middle part. The supporter obtained by such a method can be reduced in weight while maintaining substantially the same strength as that of a conventional product, can be processed economically in relatively simple steps, and has less thickness variation. Therefore, an inexpensive color cathode-ray tube having stable qualities and causing less color unevenness can be provided.

Abstract: A skirt portion of a mask body includes cut portions. The width of the cut portions along the minor or major axis ranges from 0.10×L to 0.45×L, where L is the distance from an end of the minor or major axis to a diagonal end, and the height of the cut portions along the tube axis is equal to 5% to 40% of the height of the skirt portion along the tube axis in a region near the minor or major axis.

Abstract: A color cathode ray tube has a panel portion in which a black matrix layer and plural phosphor layers are formed on the inner surface of its faceplate. The black matrix layer is provided with first-color holes for a first phosphor layer and second-color holes for a second phosphor layer. The first-color holes and the second-color holes become gradually larger in diameter from the central portion toward the corner portions of the faceplate, and the rate of variation in the diameters of the first-color holes and the rate of variation in the diameters of the second-color holes are different from each other. According to the above-described construction, there is provided a cathode ray tube in which white uniformity is improved over the entire screen.

Abstract: A cathode ray tube capable of preventing incorrect hitting of color electron beams caused by the local doming phenomenon and the initial doming phenomenon from occurring and thus preventing displacement of colors, unevenness in colors, and deterioration of luminance from occurring is provided. The cathode ray tube includes a shadow mask made of a flat plate in which a number of apertures 2 are arranged in lines, and slits 5, 6 are formed in the line direction of the apertures 2. These slits 5, 6 have inclined faces 8, 9, 11 and 12 opposed via openings 10, 13. Due to this configuration, the displacement of apertures due to the local doming phenomenon or the initial doming phenomenon caused by the thermal expansion of the shadow mask can be suppressed. Thus, displacement of colors, unevenness in colors, and deterioration of luminance caused by incorrect hitting of electron beams can be prevented from occurring.

Abstract: There is disclosed a shadow mask for a color braun tube to reduce moire by improving a structure of a beam passage hole on a mask. According to a first embodiment, in a color braun tube including a mask having many beam passage holes over emitting paths of electron beams, a mask for the color braun tube has a vertical pitch of the beam passage holes that is 2.7 and more times as long as a vertical pitch of horizontal electron beam lines scanned on a screen. According to a second embodiment, in a color braun tube including a mask having many beam passage holes over emitting paths of electron beams, a mask for the color braun tube has a vertical pitch of the beam passage holes that is 3.4 and more times as long as a vertical pitch of horizontal electron beam lines scanned on a screen.

Abstract: A color cathode ray tube includes a shadow mask having an apertured portion, an imperforate portion and a skirt portion. The shadow mask of an iron-nickel alloy is suspended within a support frame, has a descending step portion around the imperforate portion, the skirt portion which is fitted in the support frame is integral with the descending step portion, is provided with plural beads parallel with a height of the skirt portion and protruding inward. The descending step portion satisfies one of conditions (a)-(c) of (a) its height is from 30% to 501 of H0, (b) its width is from 65% to 80% of W0, or (c) its height H and width W are from 30% to 50% of H0 and from 65% to 80% of W0, respectively, where H0 and W0 are its height and width at centerlines of long and short sides of the skirt portion, respectively.

Abstract: A color selection apparatus for a cathode ray tube includes an iron mask having a longitudinal axis and a short axis and a frame coupled with the mask and tensing the mask in one direction of the longitudinal and short axes.

Abstract: Panel/shadow mask assembly including a substantially flat panel having an effective surface with a coat of fluorescent material thereon, a rail fastener fitted to a periphery of the panel wherein a surface of the rail fastener on a side of the effective surface of the panel has a radius of curvature, and a shadow mask fixed to the rail fastener under pretension, thereby doubling a foreign matter washing efficiency and preventing a quality deterioration of the flat cathode ray tube.

Abstract: A large number of micropores are formed in a surface of a metal base body of a shadow mask provided to a color cathode ray tube and a surface film is formed such that the surface film impregnates these micropores and covers the metal base body. Due to such a constitution, it is possible to realize a color cathode ray tube having a press mask of a large radius of curvature which can reduce the thermal deformation such as doming.

Abstract: A color selection apparatus for a cathode ray tube (CRT) is disclosed. The color selection apparatus includes a frame having a pair of supporting members disposed in parallel and spaced away from each other and a pair of elastic members disposed between and coupled to the supporting members, and a mask coupled to the supporting members and provided with a plurality of beam-passing apertures. Each of the elastic members is formed in a continuously nonlinear-shape in its longitudinal direction.

Abstract: A tension mask for a color cathode-ray tube includes a plurality of strips separated by a predetermined distance and connected by real bridges. The strips define slots, through which an electron beam passes, together with the real bridges. The slots are formed such that the width of middle portions of the slots is narrower than the width of upper and lower portions of the slots in order to compensate for contraction of the strips arising when tension is applied to the strips.

Abstract: Dynamic vibration absorber in a CRT having a shadow mask fastened to an inside surface of a panel by main frames, including a base part to be fitted to a non-effective surface of the shadow mask, and a vibration absorbing part having one end connected to the base part and the other end designed to make no contact with the shadow mask and the main frame, thereby attenuating vibration of the shadow mask.

Abstract: The invention provides a tension mask support frame assembly having a pair of support blade members attached to a frame. The support blade members are attached to opposite sides of the frame at a central location whereby each support blade member has a pair of distal ends extending from the central attachment point. A damping scrubber is disposed in the space between the support blade member and the frame near a distal end of the support blade members. Vibrations in the tension mask are thereby reduced through the transfer of the vibrations to the frame through rubbing action of the damping scrubbers.

Abstract: Disclosed is a shadow mask for a flat cathode ray tube capable of achieving the decrement of the phenomena of moire and the improvement of luminance and controlling a bridge shadow thereof, with an optimal design value of the vertical pitch of the apertures of the shadow mask.

Abstract: A shadow mask support frame for a cathode-ray color display tube of generally rectangular shape in top plan view. The shadow mask support frame includes two end upstands, which are located opposite each other and which are intended to support a shadow mask, and two lateral upstands, which are intended to keep the end upstands apart or separated from each other. The end upstands and the lateral upstands are of generally tubular shape and constitute an almost continuous closed hollow body containing at least one plane closed line located entirely inside the hollow body and passing inside each of the end and lateral upstands. It may be produced by folding a single metal strip or by fitting two drawn shells together.

Abstract: A cathode ray tube includes a tension mask attached to a rectangular mask frame assembly that has two longs sides paralleling a central major axis thereof and two short sides paralleling a central minor axis thereof. A pair of support blade members are attached each to one of the long or short sides at a central location. Each support blade member includes an inner edge having of a plurality of first sides formed from a relatively low coefficient of thermal expansion material and an outer edge having a second side formed of a material having a relatively high coefficient of thermal expansion. Each edge having a centroid separated from each other along the minor axis.

Abstract: Damper wire for a shadow mask in a flat Braun tube including a shadow mask, a support for supporting the shadow mask under a tension, a damper wire fitted to the support in contact with a surface of the shadow mask, wherein, the damper wire satisfies a condition expressed in an equation, T<&pgr;&rgr;L2F2n-s/m, where T denotes a tension of damper wire, &rgr; denotes mass per unit length, L denotes a total length, and fn-s/m denotes a first natural frequency of the shadow mask, thereby preventing breakage of the damper wire, but still enhancing an attenuation efficiency.

Abstract: A technique is described for lightening a shadow of a damper line for preventing vibration of a color selecting member cast on a video screen and further preventing occurrence of the shadow. In a cathode ray tube in which electron beams emitted from neighboring electron guns cross each other before passing through a plurality of apertures of a color selecting member and has an area through which both of the electron beams pass. A damper line is provided in the area through which both of the electron beams pass. Since one of the electron beam falls on a shadow cast by the other electron beam, the shadow becomes lighter.