KR950007951B1 - Front assembly for a cathode ray tube - Google Patents

Abstract

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Description

Front Assembly for Cathode Ray Tube

1 is a cutaway perspective view of a cabinet accommodating a cathode ray tube having a novel front assembly according to the present invention as a main part of the present invention.

FIG. 2 is a side view of the color cathode ray tube of FIG. 1 showing the other parts of FIG. 1 together with a cross section showing a novel front assembly of the present invention, in which a tensile foil-type shadow mask is welded and comprising a separate faceplate mounting metal frame. Perspective view.

3 is an elevational view of a funnel divided by an interval of 120 degrees in azimuth with an adjacent face plate, detailing a separate face plate mounting metal frame in which a tensile foil type shadow mask is welded according to the present invention.

4 is a perspective view showing a cross section of the front assembly and its structure according to the present invention, showing a slurry flowing through another example of a separate faceplate-mounted metal frame according to the present invention during a screening process filled with radial flow. .

FIG. 4A is a top view of the portion shown in FIG. 4 showing the slurry passage structure in detail. FIG.

5a and 5b are perspective views showing a variation of the slurry passage structure according to the present invention to facilitate the screening process filled with radial flow.

6 is a cross-sectional perspective view of another embodiment of a separate face plate mounting metal frame according to the present invention as a shadow mask according to the present invention is welded and fixed to a face plate.

7 and 7a and 7b are cross-sectional views of various embodiments of a metal frame of a face plate according to the invention.

Figure 8 is a cross-sectional view showing in detail another embodiment of the face plate mounting metal frame according to the present invention.

9 is a cross-sectional view of a funnel of a front assembly and a cathode ray tube associated therewith, illustrating an optional embodiment of a shadow mask support structure in accordance with the invention, similar to FIG.

Figure 9a schematically illustrates the tensile and compressive forces inherent in the embodiment of Figure 9;

10 and 11 are cross-sectional views of another embodiment of a shadow mask support structure improved by the present invention.

12 is a front view of another embodiment of the present invention.

FIG. 12A is a front view of a modified example in which the form of FIG. 12 is changed. FIG.

FIG. 13 is a view similar to FIG. 6, showing another embodiment of the present invention.

14 is a perspective view, partly in cross section, of a stable shadow mask support structure having at least one foot according to another variation of the present invention in which the shadow mask is mounted;

15 to 18 are cross-sectional views showing yet another variation of the present invention.

19 is a perspective view of a shadow mask support structure, showing another variation of the shape of the foot of the structure of the present invention.

20 is a perspective view in the form of a foot of another shadow mask support structure according to the present invention.

21 to 23 are plan views of yet another variation of the shape of the foot of the shadow mask support structure according to the present invention.

24 is a perspective view of the front assembly according to the present invention schematically showing the flow of the process coating agent during the manufacturing process.

FIG. 25 is a perspective view of the mask support part of FIG. 24 showing the flow of the positive coating to the part. FIG.

FIG. 26 is a view similar to FIG. 25 showing the final attachment of the process encapsulant to electrically connect the components of the front assembly according to the present invention.

FIG. 27 is a cathode ray tube similar to that of FIG. 27, with a part cut away to show another example of the change of the mask support structure and the relationship between the face plate and the shadow mask of the cathode ray tube, and a greatly enlarged mask hole. Partially cutaway plan view of the front assembly.

FIG. 28 is a partial cutaway perspective view of the front assembly of a cathode ray tube, detailing the position and orientation of a portion of another shadow mask support structure provided within the cathode ray tube; FIG.

FIG. 29 is a perspective view of an edge portion of an embodiment of the shadow mask support structure shown in FIGS. 27 and 28 with the shadow mask fixed.

30 is a perspective view of a single shadow mask support structure according to the present invention.

30A is an enlarged view showing the shadow mask support structure of FIG. 30 in more detail.

31 to 34 are cross-sectional views showing yet another variation of the present invention.

35 is a perspective view of a corner portion of the embodiment of the shadow mask support structure of FIG. 34;

* Explanation of symbols for main parts of the drawings

12: color cathode wire and 15: front assembly

16: face plate 17: inside

20: screen 21: sealing area

34: metal frame 35: shadow mask

53: slurry passage structure 154: cement

134,168: Shadow Mask Support Structure

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to color cathodic correlators, and more particularly, to a novel color water vessel front assembly having a tensile foil shadow mask. The present invention is useful in many types of color receivers, including those used in home television receivers and designed for color monitors and used in tubes of medium resolution and high resolution.

The use of tensile foil masks and flat faceplates has many advantages and benefits over conventional domed shadow masks. An important advantage is the very large power regulation capability, which can increase brightness by three times. Conventional curved shadow masks which are not tensioned tend to be dome shaped in the high brightness image area where the intensity of the electron impact is greatest. Color impurity occurs when the mask approaches the faceplate. If the tensile force is high, the tensile foil-type mask does not become domed or move with respect to the face plate and thus has greater brightness potential while maintaining color purity.

The tension foil shadow mask is part of the front assembly of the cathode ray tube and lies in contact with the faceplate. The front assembly includes a face plate to which phosphorescent phosphorus is attached, a shadow mask, and support means for a mask. As used herein, the term "shadow mask" refers to a perforated metal foil that may have a thickness of, for example, about 0.025 mm (1 mil) or less. The mask should be held under high tension at a predetermined distance known as the "Q spacing" on the inner surface of the faceplate of the cathode ray tube. The high tensile strength will fall in the range of 1.38 × 10 ⁵ to 2.75 × 10 ⁵ KPa (20 to 40 KPsi). As is known in the art, the shadow mask acts as a color selection electrode or parallax closure which ensures that the three beams only touch the assigned phosphorus, respectively.

The requirements for supporting means for shadow masks are strict. As is well known, the shadow mask must be mounted under high tension. The mask support means must have a high strength so that the mask remains floating. It is important that the guard band may be exhausted even when considering the inward movement of the mask as small as 0.0025 mm (0.1 mil). In addition, the shadow mask support means must have a shape and material composition that is compatible with (ie, comparable to) the means to which it is attached. For example, for the support means to be attached to glass, such as the inner surface of the faceplate, the support means must have the same coefficient of thermal expansion as the glass. The support means shall provide a surface suitable for mounting the mask. The support means should also be such a composition that the mask can be welded to the support means by electrical resistance welding or laser welding. The support surface preferably has such a flatness that no voids can exist between the metal of the mask and the support structure in order to maintain the intimate intermetallic contact required for proper welding.

Matching and support systems for tensile masks are known from EP-A-143,939. The frame sized to encircle the screen has spaced first and second surfaces. The tension foil shaped shadow mask has a perimeter coupled to the second surface of the frame. The frame is mated to the face plate by ball-groove indexing means. The shadow mask is inserted between the frame and the reinforcing member. When assembling the system, the frame lies between the sealing area of the faceplate and the funnel, and the reinforcing member projects from the frame into the funnel. While such a system provides an efficient means of keeping the mask in a plane parallel to the rigidly flat faceplate under high tension, the cathode ray tube is weighted due to the presence of a separate rigid member, and further processing is performed at the time of manufacture. It is necessary.

Color water tubes using tensile shadow masks are currently available on the market. The mask will be installed under high tension by simple mechanical means. In particular, very heavy mask support frames compress before and during attachment to the mask. When releasing the frame, the return force in the frame places the mask under high residual tension. During normal tube operation, electron beam shocks heat the mask and reduce the tensile force of the mask. There is an upper limit to the intensity of the electron beam that can be used to impact the screen to the extent that it does not completely relax the mask and does not lose color selection capability. Such an upper limit would be below the upper limit necessary to produce a color image of the same brightness as that made in a tube with an untensioned shadow mask. See US Pat. No. 3,683,063 for an example of this type of coffin.

The color cathode ray tube has three electron guns arranged in delta or series. Each electron gun projects an electron beam through the aperture of the mask to its respective assigned target located on the inner surface of the faceplate. The bull's-eye is in the form of phosphor deposits, typically arranged in triads of multiple points or lines. Each triad is composed of layers of red, green and blue lighters. In order to increase the apparent brightness of the display and to minimize the generation of color impurities that can result from falling into the unallocated layer of the beam, the target area is called a "grille" of black color. It includes a layer of light absorber, which surrounds and separates each point or line and serves as a "guard band" when the beam is not aligned.

The phosphorus layer is usually formed according to a ignition process. Also, a grill called "black surround" is initially applied. The target is then applied with a photosensitive slurry consisting of phosphor particles of one of the three phosphorus described. The shadow mask mounted on the rigid frame is temporarily installed to maintain an accurate relationship with the faceplate, and the coating chemically reacts on the phosphor layer projected through the aperture of the mask from a light source positioned at a position corresponding to the beam emission point of the electron tube of the finished tube. Are exposed to light to cause them. The faceplate is then separated from the shadow mask, and the coating is "developed". The end result is in the form of dots or lines that emit red, green or blue light in the excited state of the beam. The printing step is repeated for each remaining color to attach the phosphorus of the triad at the bull's eye as a coordinate relationship with each hole of the mask.

In the faceplate shielding, phosphorus for each color is commonly incorporated into process screening fluids, commonly referred to as slurries. The slurry is typically applied to the faceplate by a process known as "radial flow suffusion." The screening fluid is poured onto the faceplate while the faceplate is rotating. As the faceplate rotates, the screening fluid spreads to the edges of the silver panel, and excess liquid is scattered by centrifugal force. If there is any obstacle to the free flow of the slurry during the screening process, the radially dispersed slurry will be pushed back to corrugate the coating, which will later harden if the slurry is dried by air and heat. The effect of this nonuniformity on phosphorus density can accumulate as the faceplate is gradually screened. There are three harmful effects of the waveform. First, a thick film will be shown to the observer as a dark area on the screen. Second, transverse contamination of the collar may occur. Third, underexposure in a thick area during the ignition process may be washed away without phosphorus adhesion. Peel it off.

U. S. Patent No. 3,894, 321 to Mr. Moore relates to a method of treating a color cathode ray tube with a thin foil-type mask sealed under tensile force directly to a bulb. The patent describes sealing the foil mask between the skirt of the face plate and the junction of the funnel. The mask has two or more registration holes that engage with the face plate's fittings near the edges of the mask. The naples pass through the mating holes and fit into the concave surface of the funnel. In another Moore's embodiment, the front panel has continuous protrusions around the inner surface of the faceplate. The top surface of the protrusion is spaced Q apart from the face plate to accommodate the foil-shaped mask such that the mask is sealed into the shell of the tube. In yet another embodiment, two projections are disposed on the side of the face plate parallel to the vertical axis of the face plate containing the shadow mask. Also shown is an almost flat embodiment without a skirt on the faceplate.

It is described in a journal article written by Mr. Robinder of Tektronix Incorporated for aero-electromechanical color cathode ray tubes with ceramic components. The shadow mask is mounted to a ceramic ring-faceplate assembly where the mask is suspended by four springs in the direction of the E axis. Ceramics are also used to form two member X-ray diluents. Flat high voltage faceplates are used with glass neck flares.

A color water pipe having an untensioned shadow mask correlated with a conventional curved face plate is described in Japanese Patent No. 56-141148 to Mitsuru Matsushita. The purpose of the cited reference is to "rationalize the structure and assembly of the tube by constructing the shell with the funnel, the ceramic shadow mask mounting frame and the panel, and by forming the excess electron beam shield integrally with the shadow mask working frame."

It is a general object of the present invention to enhance the performance of the cathode ray tube by providing an improved front assembly for the shadow mask in high resolution cathode ray tubes and domestic color cathode ray tubes using a tensile foil type shadow mask. Therefore, the present invention provides a substantially flat face plate having an in-screen centrally located on the inner surface enclosed by a peripheral sealing area which is to be coupled with a funnel, and a weldable tension foil shadow provided at a distance from the inner surface of the face plate. A separate faceplate mounting frame means fixed to an inner surface between the target portion supporting the mask and the sealing area and comprising weldable metal, the mask having a central hole portion and a peripheral portion welded to the frame means, the frame A front assembly for cathode ray tubes is provided in which the bond between the faceplate and the faceplate have an area and strength sufficient to withstand all tensile forces exerted by the foil-type mask.

With reference to the accompanying drawings with the above features and advantages will be described in detail the present invention according to a preferred embodiment.

1 shows an image monitor 10 incorporating a color cathode ray tube 12 having a novel front assembly according to the present invention. The cathode ray tube 12 is notable for the planar image portion 14 that can display the image without twisting. In addition, the image portion 14 has a relatively rectangular corner as compared with the more rounded corners of the conventional cathode ray tube, so that the screen area can be used more efficiently. An anterior assembly according to the present invention consists of the components described below.

2 and 3 and 4, there is shown a high resolution front assembly 15 for a color cathode ray tube. The front assembly 15 comprises a flat or nearly flat glass faceplate 16 which is optionally finite of horizontal and vertical radius. In the embodiment of the present invention, the planar piece 16 shown as planar and flangeless has a phosphor target 18 disposed centrally at the inner surface 17, on which the electrically conductive film 19 is produced. It contains an electron beam target called screen 20 which serves to receive a uniform coating of insular. In the final step, the conductive film 19 deposited on such phosphor deposits is made of a very thin, electron-transmissive aluminum film at light reflection points.

The screen 20 is surrounded by a peripheral seal 21 which is intended to engage a funnel 22. The sealing portion 21 is shown as having first indexing grooves 26A, 26B, 26C of three V-shaped grooves which are oriented almost radially. The indexing grooves are preferably arranged around the center of the face plate 16 at equal angular intervals, ie at 120 degree intervals. As such, indexing elements 26A, 26B disposed 120 degrees apart are shown in FIG. The third indexing element is not shown, but is equally spaced from the above indexing elements 26A and 26B and disposed at the peripheral sealing portion 21. V-shaped indexing grooves are provided for indexing when face plate 16 is engaged with a suitable sheath member.

The funnel 22 is shown facing a first indexing element 26A, 26B in FIG. 3 and has a funnel sealing portion 28 having second indexing elements 30A, 30B in the same direction. Ball means 32A, 32B providing auxiliary round indexing means join the indexing elements 26A, 26B, 30A, 30B to register face plate 16 and funnel 22. The first indexing element may also be used as the indexing means during photo-screening the phosphor layer on the face plate together with the ball means.

The front assembly 15 according to the present invention is a metal frame (34) fixed to the inner surface of the face plate 16 between the screen 20 and the peripheral sealing portion 21 of the face plate 16 while enclosing the gyeongsae 18 It comprises a separate faceplate mounting frame means in the form of a). A separate faceplate mounting metal frame 34 according to the present invention is provided to support the weldable tension foil shadow mask 35 at a distance of a predetermined “Q spacing” from the inner surface of the faceplate 16. Masks shown to be planar are shown elongated, ie tensioned, in all directions in the plane of the mask. The weld indicated by the corresponding weld 33 may be spot welding. The predetermined distance may be the "Q interval" 41 as shown by the arrow in FIG. The metal frame 34 of the faceplate according to the present invention may be attached to the inner surface of the faceplate by, for example, an opaque glass material known in the art, or by a cooling coagulation cement such as a sauerreisen cement. Can be.

The neck 36 extending from the funnel 22 is shown to contain an electron gun 38 which emits three electron beams 40, 42, 44, which are covered by a conductive film 19. Selectively, the target 18 containing the phosphorescent layer for luminescence is activated. The electron beams 40, 42, 44 selectively activate the shape of the phosphorus after passing through the parallax formed by the shadow mask 35.

The funnel 22 has an internal conductive funnel coating 37 which is intended to receive a high potential. The potential is shown to be exerted through a positive button 45 attached to a conductor 47 that transmits a high potential to the positive button 45 through the wall of the funnel 22. The potential comes from a high voltage source (not shown). The potential may be in the range of 18 to 26 kilovolts, for example for the monitor shown. The means for providing an electrical connection between the electrically conducting metal plate frame 34 and the funnel coating 37 may comprise spring means 46 (FIG. 2).

The magnetically permeable internal magnetic shield 48 is attached to the faceplate mounting metal frame 34. The shield 48 does not interfere with the paths of the electron beams 40, 42, 44, but extends into the funnel 22 by a predetermined distance 49 calculated to be at full turn.

The yoke 50 surrounds the color cathode ray tube 12 at the junction between the funnel 22 and the neck 36. Yoke 50 is provided for electronically scanning electron beams 40, 42, 44 across screen 20. The central axis 52 of the color cathode ray tube 12 is shown by the dashed line.

Although the separate faceplate mounting metal frame according to the present invention may be continuous (without disconnection), in some types of screening devices, in order to facilitate slurry screening, the slurry passage structure is in contact with the inner surface of the faceplate 16 by the present invention. It is also possible to pass all excess slurry outward in the radial direction during the photodeposition process. The form of such a slurry passage structure is shown in detail in FIGS. 4 and 4a and 5a and 5b. In FIG. 4, a portion of the metal face plate frame 34 is shown to have a slurry passage structure 53 in contact with the inner surface 17 of the face plate 16. As shown in FIGS. 4 and 4A, the slurry passage structure 53 includes a column attached to the inner surface 17 of the face plate 16 and has holes 58 therebetween. In the preferred embodiment shown, the column has an effective cross section to catalyze the radial flow of slurry 54 with minimal cleaning.

Another form of slurry passage structure according to the present invention is shown in FIGS. 5A and 5B. In FIG. 5A, the slurry through hole 59 is shown as a series of ellipses that contact but not open the inner surface 17 of the face plate 16 lying below, with arrows indicating the flow of the slurry. In FIG. 5B the slurry through hole 61 comprises a series of tunnels in contact with the inner surface 17 of the face plate 16, where arrows indicate the flow of slurry. Other types of slurry through holes that can be inferred will be apparent to those skilled in the art, and all such changes will fall within the spirit and scope of the present invention.

The separate faceplate mounting metal frame carrying the weldable tension foil shadow mask according to the invention may comprise a continuous metal ring such as faceplate frame 34 in FIG. The faceplate mounting metal frame according to the present invention may be discontinuous (“broken”) or segmented like the metal faceplate frame 64 shown in FIG. Frame 64 is only discontinuous in terms of segments, and such a series of segments is continuous along the side of the mask. The frame 64 is attached to the face plate 62 with cement 66, and the attachment means may comprise, for example, a cooling coagulation cement such as sour raisen cement or an opaque glass raw material. The discontinuous metal face plate frame 64 has a gap 68 that acts as a slurry through hole. Another advantage of providing a discontinuous faceplate mounting metal frame is that if the faceplate and the frame do not have nearly the same coefficient of thermal expansion, there will be problems in fixing a separate faceplate mounting metal frame (faceplate frame according to the invention) on the glass faceplate. It is in the fact that it may be. Even if the difference in expansion coefficient is small, cracks may be formed or broken into pieces in the glass substrate if the faceplate-mounted metal frame is not imitated by the present invention. A discontinuous or segmented faceplate mounting metal frame is shown in FIG. 6, wherein the problem is eliminated by providing a segmented metal faceplate frame 64. FIG. The discontinuous faceplate mounting metal frame 64 has a tensile foil-type shadow mask 70 welded to each segment as shown by the corresponding weld reference 72.

The shape of the faceplate frame 34, which is rectangular in metal, is shown schematically in FIG. 3 according to the present invention, according to another embodiment of the present invention shown in cross-section in FIGS. 7, 7a, 7b and 8; It may also have a slurry through hole. As shown in FIG. 7, the faceplate frame 74 according to the present invention may have an inverted V shape. The face plate frame 74 is fixed to the inner surface 76 of the face plate 78 by a fillet 80 of cement composed of an opaque glass raw material. As described above, the faceplate mounting metal frame 74 supports the tension foil type shadow mask 82 at a distance of a predetermined Q interval 85 from the inner surface 76 of the faceplate 78. The shadow mask 82 is welded to the faceplate mounting metal frame 74.

The faceplate mounting metal frame according to the present invention may have the form shown in FIG. 7a, wherein the metal frame is shown in cross section as being a rod of solid metal fixed to the inner surface of the faceplate of cement. In the embodiment shown in FIG. 7B, the faceplate mounting metal frame 86 is shown in a pyramidal cross section with sides pyramid-tipped toward the shadow mask 88.

Another form of the metal frame 34 mounted with the rectangular face plate shown in FIG. 3 is shown in FIG. 8, where the rectangular face plate mounting metal frame 90 according to the present invention is a shadow mask 94. FIG. Has a shadow mask receiving surface 92 which maintains an angle of?

A preferred method of mounting the mask is to tension the shadow mask blank pre-drilled across the metal faceplate frame according to the invention with an appropriate tensioning means (not shown). The tensioned mask extends across the faceplate metal frame and is fixed by welding to the frame. Welding process can be done by electric resistance welding or laser welding. For example, in a 35.56 cm (14 inch) tube, 1000 welds are welded at intervals of about 1.0 mm (0.040 inch) around the circumferential direction of the frame to secure it to the mask. Also, as noted, the contact area of the mask support frame is preferably flat in order to secure engagement of all welds between the mask and the support structure. The flat surface can be made by wrapping, ie, rubbing the surface of the faceplate mounting metal frame (when mounted on the faceplate) on a flat surface with abrasive.

As for the ball means which form the intermediate part of the indexing element when paired, it is preferred that the ball is formed from a component having a coefficient of thermal expansion that matches the glass of the shell of the cathode ray tube. This is necessary when the final seal is final at a relatively high temperature between the funnels. The ball should have a diameter that will provide an accurate Q-gap between the shadow mask and the target area. The ball preferably has a spherical geometrical tolerance of ± 0.00125 mm (± 0.000050 inches). The balls are formed of a ceramic such as forsterite, and are preferably polished and finished by means known in the art. The grooves are formed by ultrasonic tools that have the necessary cavitation and are ultrasonically vibrated in the presence of abrasive slurry.

Regarding the composition of the other metal face frame, Alloy No. 27 supplied by Pennsylvania, Carpente Technology Incorporated of Leading Material is preferred. The coefficient of thermal expansion of this alloy will match the glass of the faceplate.

Means other than internal ball-groove elements may be used to index the faceplate and mask tension structure and funnel. For example, such indexing means may be externally attached.

FIG. 9 shows another embodiment of the present invention, which is similar to the front assembly 15 of FIG. 3 but includes a front assembly 115 that employs a support structure 134 of another tension foil shadow mask.

As shown in FIG. 9, the support structure 134 of the shadow mask according to the present invention is a face plate 16 made of cement 154 of an opaque glass material such as sold as CV-130 in Owens-Illinois. It is fixed to the inner surface 17 of. Alternatively, the cement 154 may comprise a cooling coagulation cement of the type sold by Sourreisen Siemens Co., Pittsburgh, Pennsylvania.

Such support structure 134, made of thin film metal, has a peak 156 with a first surface 158 to receive the foil-shaped shadow mask 35 under tension. The preferred composition of the support structure is a metal, such as Carpenter Alloy No. 27, manufactured by Leading Carpenter Technology Incorporated, Pennsylvania. Refers to the ridges of the structure). The first surface 158 preferably has a flat surface 159 to receive and secure the foil-like shadow mask under tension. The thickness of alloy 27 is, for example, in the range of 0.25 to 0.50 mm (10 to 20 mils).

In general, the method of mounting a mask on such support structure 134 is similar to the method described above in connection with FIGS. In addition, the peak 156 has a flat surface 159 to securely maintain all the welding contacts between the mask 35 and the support structure 134. The flat surface can be made by wrapping, ie, rubbing the surface of the support structure (when mounted on the faceplate) on a flat surface with abrasive. The width of the flat surface 159 may be in the range of 0.125 to 2.5 mm 5 to 100 mils by the present invention for securing the foil-type shadow mask under tension. After the mask is tensioned and secured to the support frame 134, excess mask material is trimmed as shown by trim lines 161.

Referring to FIG. 9A, the essence of the support structure 134 in the embodiment of FIG. 9 is the compression member 163, which defines the distance of the mask to the screen, and the large restoring force (the direction of this force is indicated by the arrow 162). It is a tension member 165 to withstand). The shape of compression and tension is shown by arrows 163A and 165A, respectively.

Another preferred embodiment of the present invention is shown in FIG. 10, where the face plate 166 has a foil-shaped shadow mask support structure 168 composed of a thin plate fixed to an inner surface 170 of the face plate. The support structure 168 has a substantially inverted V-shaped cross section in accordance with this aspect of the invention. Peak 172 of support structure 168 provides a first surface 174 for receiving a foil-shaped shadow mask 176 under tension. The second surface 178 extends radially outward and slopes down at the peak 172. It should be noted that the second surface 178 is closer to the inner surface 168 of the faceplate than the first surface 174 so that the peak 172 accurately defines the Q spacing 180 of the given mask to screen. The shadow mask 176 is fixed to the peak 172 of the support structure 168 as indicated by the weld symbol. In this embodiment of the invention the support structure 168 of sheet metal can be produced, for example, by rolling or extrusion.

Another shape of the present invention is shown in FIG. 10, where the shadow mask support structure 168 is hollow. Such support structure 168 has a hardening cement 186 therein by the present invention. The hardening cement 186 hardens to attach the shadow mask support structure 168 to the inner surface 170 of the face plate 166. The advantages of such cements are to strengthen the support structure 168 to resist distortion caused by the high tension of the shadow mask 176 and to support the support structure 168 on the inner surface 170 of the faceplate 166. It's about fixing it firmly. Sealing the cement inside the support structure has another advantage that the fixing means for the support structure does not break into the peripheral sealing portion 171 or the inner surface 170 of the face plate. What is important at the time of encapsulation of such cement 186 is that there are no voids in such cement 186, otherwise the screening fluid may enter the voids and later leak out as contaminants in the production process.

Another embodiment of a shadow mask support structure is shown in FIG. 11, where the shadow mask support structure is in the form of a hollow tube in cross section. The support structure 184 is fixed to the inner surface of the face plate 188 at the opposite surface of the screen 189. The support structure 184 has a peak 190 for receiving and securing the shadow mask 192 under tension. Peak 190 may have a flat surface 194 similar to the flat surface 159 described in connection with the embodiment of the present invention shown in FIGS. 9 and 9A. The support structure 184 is secured to the inner surface 196 of the face plate 188 by a fillet 196A, 196B of cement, which may be an opaque glass material, for example.

While describing particular embodiments of the present invention, those skilled in the art can make modifications and variations as well as other embodiments of the shadow mask support structure without departing from the scope of the present invention. For example, the shadow mask support structure according to the present invention may include the embodiments shown in FIGS. 12 and 12a and 13. The shadow mask support structure 200 in FIG. 12 is fixed to the inner surface 202 of the face plate 204 so as to support the shadow mask 206 at the mask receiving surface 208. Such support structure 200 is attached to the inner surface 202 by a fillet of cement 210 comprising an opaque glass material or cold coagulation cement as described above. The hollow interior 209 of the shadow mask support structure 200 may be preferably completely filled with cement, like the mask support structure 168 shown in FIG.

FIG. 12 shows yet another form of embodiment in FIG. 12A, in which the mask receiving surface 208A of such a support structure 200A lies at an angle of? With respect to the plane of the mask. The mask support structure 210 of another embodiment shown in FIG. 13 has a tooth form.

Various forms of the shadow mask support structure according to the present invention can be formed by various means. For example, the support structure can be fabricated by rolling, a continuous mass production method for shaping a metal strip by means of an advanced rolling mill with excellent molding accuracy and low production cost. Another viable manufacturing technique is cold extrusion, which provides accurate tolerances and excellent surface treatment, known as impact extrusion or cold forging. Casting and powder metallurgy are also viable manufacturing techniques.

The shadow mask support structure must be able to maintain the shadow mask under high tension while being subjected to high electron beams in an exact match with the face plate. This condition requires a shadow mask support structure that is stable and supports the maximum resistance to axial displacement due to the high tension of the mask applied to the support structure. Therefore, another feature of the present invention is to provide a special means for the mask support structure in order to ensure a support structure that can be stably supported. Another variation of the invention shown in FIGS. 14 to 26 relates to such a feature.

The mask support structure 334 shown in FIG. 14 is an example of a change of the support structure modified to have greater stability and resistance to the high tensile force of the mask described above. Such mask support structure 334 has a surface 354 that includes a peak that receives and holds the foil-type shadow mask 335 under inward high tension, ie, a tensile force toward the center of the face plate. Mask support structure 334 according to a variation of the invention is characterized in that it has at least one foot. This embodiment has two feet 356 and 358 disposed on the inner surface 17 of the face plate 16. The purpose of each foot is to reinforce and stabilize the shadow mask support structure 334 without being disturbed by the high tension of the mask 335. Such two feet 356,358 are rotated inward without being disturbed by the high tension of the mask 335 (where the direction in which the foot rotates is relative to the support structure itself). Also, the illustrated foot 358 has a fairly large heel 359.

An embodiment of a support structure having only one foot is shown in FIG. The support structure 360 has a first surface 362 comprising peaks for receiving and securing the foil-type shadow mask 364 under inward high tension. The support structure 360 has a second surface 366 extending radially inward. The first surface 362 accurately defines the Q spacing 372, which is the distance of the predetermined mask to screen. The support structure 360 has a foot 374 in which an end of the second surface 366 is fixed to the inner surface 368, which foot is supported against inward bending by the high tension of the mask 364. Rotate outwards to reinforce and stabilize the structure 334.

Another form of this variation is shown in FIG. 16, wherein the face plate 390 is reinforced to stabilize the support structure 378 so as not to bend inward due to the high tension of the shadow mask 392 composed of a thin plate. A support structure 378 is shown having two legs 380 and 382 having respective feet 384 and 386 disposed on an inner surface 388 of the inward rotation.

Another form of such variation is shown in FIG. 17, where the shadow mask support structure 384 has two feet 396 and 398 that rotate outwardly to support the shadow mask 400 under high tension. . Alternatively, as shown in FIG. 18, the shadowmask support structure 404 according to the present invention has two feet 406 and 408, one foot 406 rotates inward, and The other foot 408 rotates outward.

The shadow mask support structure shown in FIG. 14 is fixed to the inner surface of the face plate 16 by a fillet of cement 410, which may for example comprise an opaque glass material. Still other embodiments of the invention shown in FIGS. 15-18 can be fixed in the same manner.

Another form of such variation is shown in FIG. 19, where the shadowmask support structure 412 is similar to the support structure 366 of FIG. 15 in that it has a single foot 414. The shadow mask support structure 412 is cemented to the inner surface 416 of the face plate 418. The foot 414 has a plurality of life preservers 420 inside it. The hole 420 facilitates the cement 422 through the foot 414 by providing an edge that can engage the cement to enhance the fixation of the support structure 412 to the inner surface 416 of the face plate 418. Allow to pass In this embodiment the open end hole 520 comprises a series of opposite notches in the shape of a rectangle. The edge of the notch may be rounded.

Another embodiment of the present invention is shown in FIG. 20, wherein the shadow mask support structure 424 has two opposing feet 426, 428 disposed on the inner surface 430 of the face plate 432. FIG. It features. The feet 426 and 428 are in the form of notches that facilitate the passage of cement and also impart an edge that can engage the cement to enhance securing the support structure 424 to the inner surface 430 of the faceplate 432. Each open end has a plurality of holes 426A, 428A (the flow of cement as shown by cement 422 in FIG. Applicable to foot).

Open end holes 426A, 428A in each foot 426, 428 are in the form of a series of opposing notches in FIG. As shown in FIG. 21, the openings in the open ends of the feet 426 and 428 of the support structure 424 according to the present invention are preferably constituted by notches or holes 430 and 437 that are slung against one another. . Alternatively, as shown in FIG. 22, the hole in the foot 439 of the support structure is preferably composed of a closed hole consisting of a series of gaps 440. As shown in FIG. The form shown in FIG. 22 is unique in that some of the gaps 442 include open holes. This aspect is good in that the open gap 442 acts as a “tweezer” to capture the cement used to secure the foot according to the invention with respect to the inner surface of the faceplate.

Another form of the preferred embodiment is shown in FIG. 23, wherein the opening in the open end of the foot 444 of the support structure consists of a narrow slit 446. As shown in FIG.

There are two advantages to having holes in the shadowmask support structure, firstly, an open or closed hole facilitates the conformation of the foot to the inner surface of the faceplate to which the foot is attached, i. If not, the foot can be adapted to fit the incomplete shape. Secondly, the fixing of the shadow mask support structure to the inner surface of the face plate is greatly strengthened, since the edges that can be combined with cement are given to the inner surface of the face plate for the cement used to fix the structure.

According to the present invention, various forms of the shadow mask support structure shown in FIGS. 14 to 23 can be produced by the rolling described above. With regard to rolling, notches or gaps in the foot can be cut or drilled into dice in a flat blank before rolling.

The mask support structure is preferably hollow and formed into a thin plate. In some cases, such a structure may consist of a solid metal. As for the composition of the other supporting structure, which is the mask supporting structure 334 described above, Alloy No. 27 supplied by Carpenter Technology Inc. of Reading, Pennsylvania, is preferred because the coefficient of thermal expansion and Because it matches. Cement for attaching the foot of the supporting structure is preferably an opaque glass material known in the art. Alternatively, as noted, cold coagulation cements, such as cement sold by Sourreisen Siemens Co., Pittsburgh, may be used.

As described above, coatings such as grill coating and phosphorus for each color are typically applied in the form of a slurry that is applied in a conventional manner by pouring the slurry onto the faceplate as it rotates. The liquid spreads to the edge of the panel under the influence of centrifugal force, and the excess liquid is scattered around the face plate. If there is any obstacle to the free flow of the slurry during the rotary application process, the slurry that is scattered outwards is returned from the obstruction, thus creating a thick waveform in the coating and allowing it to adhere as it is in the drying process. However, the waveform accumulates as the process coating is applied continuously, resulting in non-uniform density and thickness of phosphorus. Therefore, it is disadvantageous if such a waveform exists.

Another feature of the present invention is the use of the shadowmask support structure of the present invention to help avoid the problems caused by unnecessarily thick waveforms in the faceplate.

Another alternatively modified front assembly for a color cathode ray tube is shown in FIG. Such front assembly 454 includes a face plate 456 having an inner surface of a screen portion 458 disposed centrally composed of an uncoated glass surface containing a process coating during the spin coating process. The coating agent is applied by pouring a base into the center of the screen portion 458 by the cup. Rotation of the front assembly for the spin coating process is shown by arrows 459, and outward flow of the emulsification process material due to centrifugal force is shown by arrows 461 at the center. The rotation speed may be in the range of 300 to 600 rpm. The shadow mask support structure 460 is fixed to the inner surface of the face plate on the opposite surface of the screen portion 458.

Mask support structure 460 is shown in detail in FIG. The mask support structure 460 has a first surface 462 for receiving and securing a foil-type shadow mask under tension. According to this feature, the mask support structure 460 has a second surface 464 inclined from the first surface 462 to the screen portion 458. According to another feature of the invention, the inclination of the second surface 464 is effective to remove from the screen portion 457 excess coating agent applied during the spin coating process. This form of removal is shown by arrow 466. As a result, there is no fear of discontinuity in the form of guiding guns, and the non-attachment of phosphorus to be washed or peeled off.

The mask support structure 460 is preferably hollow in this preferred embodiment of the present invention and is composed of a thin plate. The mask support structure 460 is fixed to the screen portion 458 by, for example, a fillet of cement 468 constituting the opaque glass material. The second surface 464, inclined from the first surface 462 to the screen portion 452, is disposed at an obtuse angle within the range of 91 degrees to 135 degrees with respect to the plane of the screen portion 458, preferably by the present invention. It is arranged about 120 degrees, such as the angle 470 shown.

Another feature of the front assembly according to the present invention is shown in FIG. 26, which schematically shows the final attachment of the process material. The centrally located screen portion 458 has a layer of conductive grill dag 472 that separates the triads of the electron beam-excited phosphorus layer 474, the color code being R (red) and G (green). ) And B (blue). The shadow mask support structure is made of a conductive composition, which in this embodiment is a solid metal and is shown by reference numeral 460A. The support structure 460A receives high voltage charge through the spring means 446 described above, which is in contact with the conductive coating 443 inside the funnel 422 of the tube 412. The support structure 460A has a conductive grill dag layer extending thereon and is electrically connected to the grill dag 472 at the screen portion 458. In the embodiment of FIG. 25, a layer of grill dag 472A is attached to a second surface 464 that slopes from first surface 462 to screen portion 458. The advantage of this form is that the screen portion 458 covered by the aluminum film is charged by contact with the grill dag 472A, which requires no auxiliary coating or electrical connection means and has the same potential as the electrically charged shadow mask support structure. do. Enumerating the complete electrical circuit from the high voltage source to the screen in turn, the conductor 449, the positive electrode button 445, the inner conductive funnel film 443, the spring means 446 and the magnetic shield 448 therein And a shadow mask support structure 434, a grill dag 472, and an aluminum film 420. As a result, the whole inside of the tube has a high potential in common except for the electron gun area.

Regarding the composition of the mask support structure 434, Alloy No. 27 provided by Carpenter Technology, Inc., a leading material, is preferred because the coefficient of thermal expansion coincides with the glass of the faceplate.

The first surface 462 is preferably flat to ensure all contact between the shadow mask and the support structure for weld integrity and preservation of proper Q spacing. The plane can be formed by lapping, ie grinding the surface of the support structure (when fixed to the face plate) against a flat surface with abrasive. The size of the plane by this baling ranges from 0.075 to 3.0 mm (3 to 120 mils). Another advantage of lapping is that all grill dags and contaminants that interfere with proper welding are removed from the first surface.

As is well known, the shadow mask support structure must be high enough to keep the mask floating, which is important within the protective frequency at which the inward motion of the mask, as small as 0.025 mm (0.1 mil), expands. It is also preferred that the shadow mask support means have such a shape and material composition that can match the means to which it is attached. For example, if the support means is attached to glass, such as glass on the inner surface of the face plate, the support means must have the same coefficient of thermal expansion as the glass and must be able to bond with the glass in its composition. In addition, the support means must have such a composition and structure that the mask can be secured to the support means by a productive technique such as electrical resistance welding or laser welding. It is also essential that the support means provide a surface suitable for mounting and securing the mask. The composition must be suitable for machining or other forms of shaping so that it can be formed in a nearly complete plane such that no voids can exist between the metal of the mask and the support structure to maintain perfect contact necessary for proper masking.

In Figures 27-29, another preferred embodiment of the present invention includes a separate shadow mask support structure 548 that is preferably constructed of ceramic material. It has a separate cap 580 made of a separate metal strip to secure the shadow mask 550. Cap 580 preferably includes a weldable material that secures shadowmask 550 by a weld. The metal strip may be attached to the surface 582 of the ceramic material by suitable cement.

The cap according to the present invention may comprise a layer of weldable metal that may be applied by electroplating the metal on the ceramic material or by attaching the metal to the ceramic material by techniques such as flame spraying or plasma arc spraying. Frited pastes and resinates may be used as the weld base, but regardless of the composition, it is essential that the weld face have a sufficient thickness to accept the melt without sacrificing a perfect weld.

The shadow mask support structure 548 according to this embodiment is shown in FIG. 27 as having four separation rails 548A to 584D, with two rails 548A and 548B shown in FIG. . The inner surface of the face plate 524 disposed between the screen 528 and the sealing portion 534 that receives and supports the rail under the tension of the foil type shadow mask 550 at a predetermined distance from the screen. 526 is fixed. The assembly includes means for connecting four rails 548A to 548D to form a generally rectangular single shadow mask support structure (a four rail structure is shown in FIG. 27). Preferred means for connecting the four rails include a continuous or discontinuous weldable metal strip fixed on top of each rail to secure the shadow mask 450 by welding. The metal strip may be attached to the surface 482 of the ceramic material by suitable cement (which is described later in nature). In the embodiment shown in FIG. 29, metal strip 580 connects two rails 548A, 548B at the joint surface of the rail.

In the embodiment shown in FIG. 30, the shadow mask support structure has a single frame 588 made of ceramic. As in the embodiment shown in FIGS. 27-29, a single frame 588 is secured to the inner surface of the faceplate and surrounds a screen that receives and supports a foil-shaped shadow mask under tension at a distance from the screen. The single frame may also have a separate cap of weldable metal in the form of a continuous or discontinuous metal strip, similar to the cap 580 of FIG. 29 to secure the shadow mask by welding. The illustrated cap 580 is shown in FIG. 30A with a cross section of a continuous or discontinuous metal strip 589 where the discontinuous cross section is shown as a separate island of metal attached to a single frame 588. In addition, the metal strip is discontinuous in that it does not require the market of the strip at the edge when the mask is tensioned by pulling the same on four sides rather than at the edge.

Another form of a metal cap according to the present invention is shown in FIGS. 31-33. FIG. 31 is made of ceramic material and shows the metal cap 580 of FIG. 29 secured to the rail 548B shown schematically. The metal cap 580 is fixed to the rail by the beads 590 of cement. The rail 548B is fixed to the inner surface 526 of the face plate 524 by beads of cement 583. The support structure shown in FIGS. 22 to 35 is fixed in a similar manner to the face plate by beads of cement. Since ceramic is a very efficient electrical insulator, an electrical passage must be provided from cap 580 to screen 528. As shown in FIG. 29 and in more detail in FIG. 31, a passage is provided by applying ceramic to the electroconductive dag 592 and the screen 528. Although not shown in the respective figures, this dag layer is also well applied to another form of shadow mask support means according to the present invention.

As shown in FIG. 32, the metal rail has a creek 594 overlapping the side of the mask support structure and fixed with cement 592. As shown in FIG. As shown in FIG. 33, the crown 596 preferably fits into the mask support structure. Such tenonable crowns are preferably free of voids or edges where contaminants, such as residues of the screening fluid, will remain that may interfere with the operation of the finished tube. The crown may be secured to the mask support structure by suitable cement.

Referring back to FIG. 29, the electrical path from the high voltage source to the screen 528 and the film of aluminum 530 thereof is similar to that described with respect to FIG. 1 and comes into contact with the conductive film 560 therein. A contact spring 578 similar to the spring means 46 of FIG. An electrical passage from contact spring 578 to shadow mask 550 is shown in FIG. 29, where contact spring 578 is welded to an already fixed shadow mask 550 as indicated by the respective weld symbols. . Electrical contact with the metal cap 580 is welded and made. The electrical path from the shadow mask to the screen 528 is provided by the coating of the electroconductive dag 592 shown in FIGS. 29 and 31.

Another form of a preferred embodiment of the present invention is shown in FIGS. 34 and 35, wherein a separate metal hoop 598 is provided with a separate hoop support means fixed to the inner surface 601 of the face plate 602. 600). As a result, the hoop 598 obtains at least most of its rigidity from the face plate 602. The separate hoop support means 600 according to the invention, so-called "buffer strips", is preferably composed of a ceramic material (in the present invention, the "hoop" is a continuous series of metal shaped into squares to match the aspect ratio of the faceplate of the tube). Band or loop). The ceramic material according to the present invention is characterized by having a coefficient of expansion equal to the coefficient of thermal expansion of the glass of the face plate 602. The ceramic may have a coefficient that is halfway between the coefficient of the glass and the metal hoop to efficiently absorb the stresses generated by the different expansion and contraction coefficients of the glass and the metal hoop. The metal hoop 598 is secured to the ceramic material, which is secured to the face plate by suitable cement shown by fillets of cement 604 and 606. In all cases, in addition to including the fillet of cement, cement is applied between the parts attached for further fixing, ie between the hoop 598 and the ceramic material and between the ceramic flames and the glass of the faceplate.

For example, the coefficient of thermal expansion of the component can be as follows.

Separate metal hoop (598): 100 × 10 ^-7 / ℃

Separate ceramic hoop support means (600): 105 × 10 ^-7 / ℃

Glass of face plate 602: 106 × 10 ⁻⁷ / ° C.

Note: The quoted coefficients are in the temperature range of 25 ° C (outside temperature) to 430 ° C (the temperature at which the glass material becomes opaque in the fritting cycle).

As the composition of the hoop 598, Alloy No. 27 manufactured by Pennsylvania, which is a metal provided with a counting table, Carpenter Technology of Reading Material, and Incorporated, is preferred. In this embodiment, the ceramic hoop support means 600 has a coefficient of thermal expansion very similar to the glass of the faceplate according to the invention. Alternatively, the hoop support means 600 according to the present invention may have a coefficient of thermal expansion, ie 107 × 10 ⁻⁷ / ° C., between the coefficients of the glass and metal hoop 598.

With a separate ceramic hoop support means according to the invention it is possible to use inexpensive rail metal instead of expensive alloys. For example, cheaper steels can be used better than fully suitable alloys, because ceramic buffers can interpolate the coefficients of thermal expansion and large imbalances of the metal and glass of the faceplate. An example of such a metal is 430 stainless steel, which has a coefficient of thermal expansion of 111 × 10 ⁻⁷ / ° C. in the range of 25 to 430 ° C.

In FIG. 35, the shadow mask 608 is fixed to a separate metal hoop 598 by welding. In this embodiment, the hoop 598 itself has a strength that can withstand the return force of the tension foil-type shadow mask. However, an additional resistance to inward high tensile strength is provided by the ceramic hoop support means 600, which is fixed integrally to the glass of the faceplate and thus takes its strength almost intact.

The ceramic material may consist of a product known as "postterite", commonly called magnesium silicate. The ceramic is a refractory material which can be formed into a rail according to the invention by dry pressing, or preferably by extrusion. It is essential that the precision and linearity of the dry press-molded or extruded form be maintained after combustion and the torsion to be minimized. In addition, the composition of the ceramic must be chemically consistent with the glass of the faceplate and the composition of the weldable metal cap or scrip. In addition, the ceramic must be such a composition that the interior environment of the tube is not contaminated by the divergence or dispersion of the solidified material.

The ceramic composition or the oxide composition is as follows.

Component weight%

Aluminum Oxide 9.49

Silicon Dioxide 30.69

Magnesium oxide 43.38

Potassium Oxide 2.38

Calcium Oxide 1.89

Zinc Oxide 12.17

The extrusion group comprises a ceramic composition, an organic binder-clean system and 15 to 35% water, depending on the required extrusion conditions.

Because of the exothermic reaction due to the hydrolysis of magnesium oxide, the components are mixed in advance and then mixed with an appropriate amount of water to hydrolyse the magnesium. The components are combined with sufficient water to break up the components to form a slurry.

The components are finely mixed thoroughly using ball grinding or other suitable technique to provide very high densities. When carefully mixed, they are homogeneous in the order of micrometers. Extrusion is used to form shadow mask supports, and one or more baking agents are added to the dry ingredients to facilitate smooth extrusion at minimum pressure. For example, 3% by weight of the predetermined agent Methocel A4M (relative to the ceramic composition) may be added to the components described above. In addition, 1% by weight of glycerin and 2% by weight of polyvinyl alcohol are added to the aqueous solution to promote mass flow and preburn the mask support structure.

Methocel A4M is a cellulose ether available from Dow Chemical Company, Midland, Mich., And polyvinyl alcohol is available from Air Products & Chemical Company, Inc. of Kentucky, Calvert, Glycerin and other chemicals are available from Fisher Scientific Co., Pittsburgh, Pennsylvania. Although specific suppliers and names are cited, equivalent materials of equivalent nature may be used.

When dry press molding is used to form the mask support structure, only 2-1 / 2% polyvinyl alcohol and 1/2% glycerin are needed. The combustion temperature is typically 2550 ° C. with a holding time of about 2 hours. Ceramic compositions having a coefficient of thermal expansion in the range of 105 × 10 ⁻⁷ / ° C. to 107 × 10 ⁻⁷ / ° C. can be mixed and used in the production area to meet the requirements of varying products.

The cement used to secure the shadow mask support structure to the face plate (i.e. the beads of cement 583 in FIG. 31) and the cement used to fix the metal strip and cap to the structure (i.e. in FIG. Beads of cement 590 may be provided with an opaque glass raw material sold under the name CV / 685 in Owens-Illinois, Toledo, Ohio. Alternatively, the cement may be an intercoagulant cement of the type sold by Sourreisen Cement Company, Pittsburgh, Pennsylvania. Opaque glass materials can be used to integrally bond the ceramics of the mask support structure to the glass of the faceplate, and the two components are ceramics according to the classification, thus "welding", i.e., by finely curing the two ceramic components, You can join. By integrally adhering to the glass, the ceramic mask support structure according to the present invention is supported in the glass, and the structure can withstand the restoring force due to the high tension of the foil-type shadow mask. Fixing the shadow mask metal to the metal is carried out by electric spot welding, preferably by laser welding.

As for the size (quoted in the example), the width of the weldable metal to accommodate and fix the shadow mask (i.e. cap 580 of FIG. In fact, having a width that falls within the wide range, the metal crown 594 in FIG. 32 is an embodiment of such a size. The thickness of the metal should be about 1.25 mm (0.05 inch) and should be suitable for welding without sacrificing weld integrity. Ceramic rails for use with a 51 cm (20 in) rectangular water pipe are 8.9 mm (0.350 in) high and 6.25 mm (0.250 in) wide. The cross-sectional shape may be square or inclined slightly inward in the vicinity of the mask mounting surface. Opposing pairs of four rails may each have a length of about 31 cm (12 inches) and 40 cm (15.9 inches). The Q spacing is about 10 mm (0.399 inches) in a 20 inch square tube, and this height includes the thickness of the metal cap. The typical size of the shadow mask support structure for a 36 cm (14 inch) square tube is 7.0 mm (0.275 inch) in Q spacing and 5.7 mm (0.225 inch) in width. Opposite pairs of four rails have a length of about 21 cm (8.2 inches) and 28 cm (10.9 inches).

A preferred method of mounting the mask is to tension the blank of the shadowmask perforated across the tensionable mask support structure with the tensioning means described in connection with FIGS. In addition, it is necessary that the weldable metal cap or strip has a flat surface to secure all fine contacts between the mask and the cap or strip. Flat surfaces may be made by surface grinding or lapping, ie, rubbing the surface of the support structure (when mounted on the faceplate) on a flat surface with abrasives.

Claims (7)

Nearly flat faceplate with a centrally disposed phosphor screen on the inner surface 17 surrounded by a peripheral sealing area (21) intended to align with a funnel (22: a funnel) (16: substantially flat faceplate) and a foil shadow mask (35) under tension at a predetermined distance from the inner surface 17 of the face plate 16 under tension. And frame means 34 attached to the inner surface 17 between the sealing portion 21 and the screen 20 for maintenance. The shadow mask 35 has a perforated center. In a front assembly (15) for a cathode ray tube (12) configured to have a central apertured area and a peripheral portion attached to said frame means (34), said frame means (34) at least partially welded Made of a metal so that the shadow mask 35 can be welded against it, and the frame means 34 is also provided with the screen 20 of the shadow mask 35 in the cathode ray tube 12. A front assembly for a cathode ray tube, characterized in that configured to be arranged on the side. 2. A frame according to claim 1 wherein the frame means 34 comprises a discontinuous or segmented metal frame 64 attached to the inner surface 17 of the face plate 16. A front assembly for a cathode ray tube, characterized in that. 3. Frame means (74) according to claim 1 or 2, wherein the frame means is frame means (84) having a solid round cross-section or frame means (74) having a triangular cross-section. A front assembly for a cathode ray tube, characterized in that. 3. The frame means according to claim 1 or 2, wherein the frame means is frame means 90 having a substantially rectangular cross-section or frame means 86 having a trapezoidal cross-section. A front assembly for a cathode ray tube, characterized in that. A faceplate with a centrally disposed screen area 458 internally for receiving process coating materials in the spin-application process. And a front assembly for a color cathode ray tube having a shadow mask support structure, wherein the shadow mask support structure 460 is foil-shaped. A first surface 462 for receiving and fixing a foil shadow mask and the first surface to guide the excess amount of the coating material applied during the spin coating process from the screen portion. By having a second surface 464 inclined from 462 towards the screen portion 458, discontinuities in phosphor application that are visible to the viewer are created. Prevention, and further, it washed exit (wash-off) or peel off the exit color cathode-ray tubes characterized in that the front assembly is configured to prevent (flake-off) according to the phosphorus mibuchak. A faceplate and frame means 548 having a peripheral sealing area intended to mate with a funnel and a centrally disposed phosphor screen on the inner surface In a front assembly for a color cathode ray tube, the frame means 548 is a foil-shaped shadow at a predetermined distance from the screen. Four separate rails 546A of ceramic attached to the inner surface on both sides of the screen 528 between the seal and the screen to receive and support a foil shadow mask under tension; 548D: four discrete rails and the separated rails together to form a generally rectangular unitary shadow mask support structure. Interconnecting means 580, the connecting means 580 being continuous or discontinuous and superimposed on each of the rails to receive and secure the shadow mask 550 by welding. A front assembly for a color cathode ray tube, characterized in that it comprises a weldable metal cap (580: a continuous or discontinuous weldable metal cap). A color cathode ray tube comprising a peripheral sealing area intended to be matched with a funnel and a faceplate having a centrally disposed phosphor screen on the inner surface In a front assembly for a color cathode ray tube, a foil shadow mask 608 is tensioned at a predetermined distance from the inner surface of the face plate 602. And a separate metal frame 598 disposed between the sealing portion 21 and the screen 20 to support the metal frame 598, wherein the metal frame 598 has a separate flame support means ( 600, which is integrally attached to a separate frame support means and such frame support means 600 is attached to the inner surface 601 of the face plate 602 so that the metal frame 598 is attached thereto. Prize most of the stiffness A front assembly for a color cathode ray tube, which is configured to be obtained from a base plate (602).

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