TW463198B - Cathode-ray tube with internal magnetic shield - Google Patents

Abstract

A CRT with an internal magnetic shield is provided, which corrects the pincushion- or barrel- shaped raster distortion effectively. The CRT is comprised of a vacuum envelope and an internal magnetic shield. The envelope has a face panel, an electron gun, and an electron beam path through which an electron beam emitted from the gun penetrates. The shield, which is located in the envelope between the panel and the gun, includes a hollow body having a shape like a frustum of a quadrangular pyramid, and a pair of flanges. The body has a first opening located on a side of the gun and a second opening located on a side of the panel. The body is located to surround the path so that the electron beam penetrates through the first opening, an inside of the body, and the second opening toward the panel. The pair of flanges are fixed to the body near the first opening and protrude inwardly to be opposite to each other through the path. A deflected magnetic field generated in the envelope is attracted toward the pair of flanges.

Description

4 63 < few

V. Description of the Invention (1) Technical Field The present invention relates to a cathode ray tube (CRT). In particular, it has an internal magnetic shield that can correct pincushion or barrei-shaped raster distortion on the screen ^ , CRT. i Know-how description. Often, color CRTs have an internal magnetic shield to magnetically shield the electron beam. Second, to avoid unwanted external magnetic fields such as geomagnetism and magnetic% shields generated by peripheral circuits, they are formed of metal plates. The hollow part has a slightly quadrangular pyramid shape &. The shield has a lower opening on the panel side and an upper opening on the electron gun side. Deflection magnetic vehicle (defl). To avoid the impact, partly by the deflection magnetic department, in order to correct the pin pad loss, it was published in the 1994 issue, published in 1995 and 1996. However, The problem of the internal magnetic screen-like grating distortion of the known technology is disclosed, and the shield opening exposed on the grabbing side is a magnetic field generated by the magnetic deflection at a proper position of the magnetic field generated by the shield so as not to block the yoke). However, in recent years, the magnetic field generated by light is used to penetrate the true or barrel grating distortion in the mask. This technique is disclosed in, for example, Japanese Laid-Open Patent Publication No. 6 "3 1 0 04 7", Japanese Laid-Open Patent Publication No. 7-1 05 868 63, and Japanese Laid-Open Patent Publication No. 8-1 71 86 866. Nos. 6- 3 1 00 47 and 7- 1 0 5 8 6 863 'has no way to fully correct pin cushion distortion or barrels. Known techniques in Bulletin 8- 1 7 1 8 686 6 Inside

4 63 V. Description of the invention (2) --- * --------- Internal magnetic shield, inner wall. Because of 1, the opening on the electronic grabbing side will have the height of the flange protruding toward the funnel-shaped portion c. 2 'The probability that the flange will contact the inner wall of the funnel-shaped portion increases as the length of the flange spreads over the stroke. If the flange is in contact with the inner wall, the graphite layer coated on the inner wall may peel or peel off. -4 # ί, the height of the flange is limited, and as a result, the problem of pin cushion distortion or barrel optics cannot be completely corrected. Therefore, the object of the present invention is to provide a CRT with sufficient correction of S-pin distortion or barrel grating distortion. Another object of the present invention is to provide a CRT with an internal magnetic shield which can effectively correct pin pad distortion or barrel grating distortion. Another object of the present invention is to provide a CRT with an internal magnetic shield that can correct pin chirp distortion or barrel grating distortion and have a convergence effect or correct a convergence error. The above unspecified purpose will make it clearer to those skilled in the art by the following description. -The CRT according to the invention has: (a) a vacuum tube; a vacuum tube having a panel and an electron grab inside; the vacuum tube having an electron beam path through which an electron beam emitted by an electron gun passes; and (b) an internal magnetic shield in the vacuum tube It is located between the panel and the electronic grab;

Page 7 463198 V. Description of the invention (3) The shield has a hollow body 1 with a slightly quadrangular truncated cone shape and a pair of flanges. The hollow body has a first opening V on the electronic grabbing side and a first opening V on the panel side. An open α y hollow body surrounds the path so the electron beam will pass through the interior of the first open 5 hollow body and the first opening to the panel; the pair of flanges is fixed at the position where the hollow body is close to the first opening, and the pair of flanges pass through The paths protrude inward towards each other * »where the deflection magnetic field generated in the vacuum tube is attracted towards the pair of flanges. According to the CRT of the present invention, the internal magnetic shield has the pair of flanges fixed to the hollow body near the first opening. The pair of flanges project inwardly toward each other through the path in the vacuum tube. The deflection magnetic field generated in the vacuum tube is attracted toward the pair of flanges β. Therefore, the deflection magnetic field in the vacuum tube is extended along the longitudinal axis of the vacuum tube due to the attraction of the magnetic field. The expansion of the magnetic field reduces the component of the deflection magnetic field that causes pin cushion distortion or barrel grating distortion, and thereby corrects pin cushion distortion or barrel grating distortion. Moreover, because the pair of flanges protrude inwardly toward each other through the electron beam path in the vacuum tube, the effect of expanding the deflection magnetic field becomes stronger. Therefore, the sensitivity of the pincushion distortion or barrel grating distortion is positive. In addition, since it is impossible for the pair of flanges to contact the inner wall of the vacuum tube, the length or protruding height of the pair of flanges is reached. As described above, according to the coffee of the present invention, it is possible to sufficiently correct the pin loss.

V. Explanation of the invention (4) True or barrel-shaped grating distortion Therefore, the effect of weakening the deflection magnetic field component becomes stronger and at the same time, the protruding height or the length of the pair of flanges can be set as large as possible. This means that the shape of the pair of flanges can be freely designed. As a result, by appropriately designing the shape of the pair of flanges, it is possible to correct the pinch distortion or barrel grating distortion and have a convergence effect or correct a convergence error. According to the CRT of the preferred embodiment, the pair of flanges extend along the vertical axis of the vacuum tube and are perpendicular to the vertical axis. The deflection magnetic field attracted to the pair of flanges is mainly a vertical deflection magnetic field. In this embodiment, there is another advantage in that pin cushion distortion or barrel grating distortion in the upper and lower end regions of the CRT screen can be effectively corrected. In another preferred embodiment according to the present invention, the projecting degree of the pair of flanges changes along the extending direction of the pair of flanges. In this embodiment, one advantage is that the effect of attracting the deflection magnetic field can be controlled locally, and the correction level of pinch distortion or barrel grating distortion can be finely adjusted. Flat disc tuning According to another preferred embodiment of the present invention, the shape of the pair of flanges can be selected from square, trapezoidal, circular segments, or triangles. In this embodiment, another advantage is that the effect of the suction bow and the deflection group ^ can be easily simulated by a computer because the shape of the magnetic field of the pair of flanges is simple, so the time required for the design and trial production of the shield can be reduced. The deformation is formed integrally with the hollow body according to another preferred embodiment of the present invention. In this embodiment, only a part of the hollow body is bent, which can be easily manufactured, and the cost can be reduced. For example, the pair of flanges and shields has another advantage because the shields only report to the pair of flanges.

Page 9 4 63 1- 'V. Description of the invention ¢ 5) According to another preferred embodiment of the present invention, the pair of flanges may be formed separately from the hollow body of the shield and then fixed to the hollow body. In this embodiment, there are further advantages described below. First, by adjusting the fixed positions of the pair of flanges and hollow bodies, it is required to finely adjust the effect of attracting the deflection magnetic field and the pincushion distortion or barrel grating distortion correction level. Secondly, because the pair of flanges can be manufactured separately from the hollow body of the shield, the shape of the pair of flanges can be more complicated. Therefore, it is easier to control the effect of the attracting deflection magnetic field, and it is more effective to correct pin cushion distortion or barrel grating distortion. .Best Embodiment B 彳 The preferred embodiment of the present invention will be explained below with reference to the drawings. First Embodiment As shown in Fig. 1 ', the color CR τ 80 according to the first embodiment of the present invention has a vacuum tube 90 made of glass. The inside of the vacuum tube 90 is maintained in a specific high vacuum state. The vacuum tube 90 is formed by a panel 81 ', a skirt portion 82, and a funnel-shaped portion 83. The panel 81 is approximately a flat square. The Fei curtain is formed on the panel 81. As shown in FIG. 1, the vertical axis 81 of the CRT 80 is a vertical panel 81. Here, the vertical axis is defined as the Z axis. The X-axis is defined as the direction in which the vertical z-axis extends laterally. The γ-axis is defined as the direction in which the Z-axis extends vertically. The panel 81 is located on the X-Y plane formed by the X-axis and the γ-axis in FIG. 1. shape

4 6 3η V. Description of the invention (6) ----- The upper and lower ends 81a and 8113 of the panel 81 are away from the ζ in the vertical direction along the Υ axis. 2 axes. The skirt part 82 is formed integrally with the panel 81. The open end of the skirt portion 82 opposite to the panel 81 is connected to the corresponding open end of the funnel-shaped portion 83. The funnel-shaped portion 83 is approximately conical and has a tubular neck on the other end of the opposite panel 81. A fluorescent screen 84 is formed on the inner surface of the panel 81. The red, green, and blue fluorescent materials are regularly arranged on the entire screen 84. In the vacuum tube 90, a color selection electrode 87 is located near the panel and is opposite to the screen 84. The color selection electrode 87 has a plurality of openings so that the electron beam 86 can selectively penetrate the screen 84. An internal magnet The shield 10 is located in the funnel-shaped portion 83 to shield the unnecessary external magnetic field. The shield 10 has an upper opening 3f and a lower opening ^, which allows the electron beam 86 to penetrate to the fluorescent screen 84, the upper opening 13f and the lower The openings i3e are arranged along the z-axis. The shield 10 is separated from the inner wall of the funnel-shaped portion 83. The shield " 10 and the color selection electrode 87 are fixed together on an approximately square frame 89. The frame 89 is fixed to the support member by The inner wall of the skirt 82. In the neck 83a, there is an electron grab 85 that can emit three electron beams γ to green (G), blue (B), and red (R). A deflection yoke 88 is on the neck A portion of the funnel-shaped portion 83 surrounding the outside of 83a. The electron beam 86 emitted by the electron grab 85 passes through the magnetic field level and vertical deflection generated by the deflection yoke 88 to scan the entire screen 84. The scanned electron beam 86 passes through The openings of the color selection electrode M are then selectively Click on the 6 'β or [Ying Guangmu 84? Color phosphor material and inspire them to generate an image according to the input signal in the firefly

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V. Description of the invention σ) on the light curtain 84 and seen by the viewer via the panel 81. FIG. 2 is a detailed structure of the internal magnetic shield 10. As shown in the figure, the upper part of 〇 is on the electron gun side 85 and the lower part of the shield 10 is on the panel! . The vertical axis of the shield 10 is coaxial with the z-axis direction. As shown in Fig. 2, the shield 10 has a hollow body 13 having a substantially quadrangular truncated cone shape. The hollow body 13 is composed of side plates i3a, 13b, 13c, and 13d formed of four magnetic materials. The side plates i3a * 13c have a stepped surface of the same shape. The side plates 13b and 13d have trapezoidal faces of approximately the same shape. The side plates 13b and 13d have V-shaped grooves 12 at the upper ends. The lower sides 13aa, 13ba, 13ca, and 13da of the four side plates 13 &, 13b, 13c, and 13d form a lower opening 13e that is approximately square. The upper sides 13ab, 13bb, 13cb, and 13db of the four side plates 13a, 13b, 13c, and 13d form an upper opening I 3 f that is approximately square. The lower opening 1 3 e is larger than the upper opening 1 3 f. The grooves 12 of the side plates 13b and 13d are to prevent the electron beam 86 from being misaligned due to the known geomagnetism. In the vacuum tube 90, the shield 10 is fixed in the following manner. In particular, as shown in Fig. 1, the side plates 13a and 13c are located in the up and down positions, respectively. The side plates 3b and 1 3 d are located at the left and right positions, respectively. The upper opening 1 3 f is located on the electronic grabbing side 8 5 and the lower opening 1 3e is located on the panel side 81. The side plates 1 3a and 1 3c extend horizontally along the X axis. The side plates 13b and 13d extend straight along the γ axis. The side plates 13a and 13c are used to shield a vertical magnetic field along the γ axis. The side plates 13b and 1d are used to shield the horizontal magnetic field along the X axis. A pair of square flat plate-shaped flanges u protrude from the upper sides 13ab and 13cb of the side plates 3a and 13c, respectively. The flange ^ does not extend across the entire i3ab and 13cb,

Page 12 4 6 ^ 1 9L V. Description of the invention (8) In other words, the flange 11 is only at 1 3 a b and 1 3 c b without extending to the end position. The flange 11 covers the upper opening i3f protruding toward the longitudinal axis of the hollow body 13, in other words, the flange 11 is convex inward from the edges of 13ab and 13cb. In the vacuum tube 90, the flanges 11 are approximately staggered to Z_ and are aligned with each other along the Y axis, as shown in FIG. A pair of square flat plate-shaped flanges 14a and 14b protrude from the V-shaped upper side 13bb of the side plate 13b. The flanges 14a and 14b do not extend over the entire 13 ^, in other words, only at the edge 1 3 bb without extending to the middle and end positions. The flanges 14a and 14b cover the upper opening protruding to the longitudinal axis of the hollow body 13. In other words, the flanges 14a and 14b are convex inward from the edges of 13bb. A pair of square flat plate-shaped flanges 14a 'and 14b' protrude from the V-shaped upper side 13db of the side plate 13d. The flanges 14a 'and 14b' do not extend over the entire i3db, in other words, 'only at the edge 1 3db without extending to the middle and end positions. The flanges 14a 'and 14b' cover the upper opening 13f protruding toward the longitudinal axis of the hollow body 13, in other words, the flanges 14a 'and 14b' are convex inwardly from the edges of 13db. The 'flange 1 4 a and 1 4 a' in the vacuum tube 90 are approximately perpendicular to the z-axis and along (the axes are opposed to each other. Similarly, the flanges 14 b and 14 b are approximately perpendicular to the z-axis and A are opposed to each other along the X-axis. "Here, the flanges 11, 14a, 14b, 14a, and 14b are formed with the hollow body 13 by a bending process. Therefore, the flanges n, Ua, Hb, and 14b are the same as the hollow body M. Made of the same magnetic metal. 乂 The color CRT80 according to the first embodiment of the present invention according to Figs. 1 and 2, as described above, near the S 'air shield] 0 has-a pair of magnetic flanges 11 fixed to the hollow body 13 90 hollow 4 ports 13aM〇13cb above. The pair of flanges 11 protrude inward toward each other in the vacuum tube through the electron beam path. The pair of flanges are along the γ axis

Page 13 V. Description of the invention (9) The flange 11 produced by the vertical protrusion and yoke 88. Extend horizontally along the X axis. Therefore, the deflection magnetic field used to scan the electron beam 86 by the deflection magnet in the vacuum tube 90 will be attracted to this. Therefore, the magnetic field attracts the deflection magnetic field to expand along the longitudinal axis (Z axis) of the vacuum tube 90. The expansion of the magnetic field reduces the component of the deflection magnetic field that causes pin cushion distortion or barrel grating distortion, and thereby corrects pin cushion distortion or barrel grating distortion in the upper and lower areas of the screen. Moreover, because the pair of flanges 11 project inwardly toward each other across the electron beam path in the vacuum tube 90, the effect of expanding the deflection magnetic field becomes stronger. As a result, sensitivity to correct pincushion distortion or barrel grating distortion is enhanced. Moreover, since the pair of flanges 11 cannot contact the inner wall of the vacuum tube 90, the length or protruding height of the pair of flanges can reach a satisfactory value. As described above, according to the color of the first embodiment of Figs. 1 and 2, it is possible to effectively correct pin cushion distortion or barrel raster distortion. Therefore, the effect of weakening the deflection magnetic field component becomes stronger while at the same time, the protruding height or the length of the pair of flanges 11 can be made as large as possible. This means that the shape of the pair of flanges 11 can be freely designed, in other words, the height Η and the length L (Fig. 2) of the flanges i? Can be freely set. As a result, by appropriately designing the shape and size of the pair of flanges 11, it is possible to effectively correct the pin cushion distortion or the barrel grating distortion and the convergence error. In addition, the 'CRT80 according to the first embodiment further has flange pairs u, 14a, 14b, 14a', and 14b 'fixed to the upper side of the opening 13f of the hollow body 13, and 13db. 14b and 14b 'protrude inwardly toward each other through the electron beam path in the vacuum tube 90. The flanges 14a, 14b, 14a, and 14b protrude horizontally along the X axis and along the

Page 14 463198 V. Description of the Invention (ίο) The Y-axis extends straight. Therefore, the deflection magnetic field generated in the vacuum tube 90 is attracted toward the flanges 14a, 14b, I4a ', and 14b, a. Therefore, the deflection magnetic field of the vacuum tube 90 expands along the axis (Z axis) because of the magnetic field attraction. The expansion of the magnetic field weakens the component of the deflection magnetic field that causes pin cushion distortion or makeup raster distortion ’and thereby corrects pin cushion distortion or barrel grating distortion on the left side of the curtain. End zone Second Embodiment Fig. 3 is a color CRT internal magnetic shield of a second embodiment of the present invention. The shield 20 corresponds to the case where the flanges 14a, Ub, 14a, * 14b, b of the shield of the CRT 80 in the first embodiment of Figs. 1 and 2 are removed. The crt of the second embodiment has the same structure as that of FIG. I crt 80 except that the shield 10 is replaced by the shield 20. Here, the explanation of the same structure is omitted for simplicity, and FIG. 3 is indicated by the same reference numerals. The same parts as the first embodiment. As shown in FIG. 3, the internal magnetic shield 20 has a pair of rectangular flat plate-shaped flanges respectively protruding from the upper sides 13 "and 13 of the side plates 13a and 13c ^ convex ^ to the upper opening of the U longitudinal axis of the hollow body ^") In other words, the edge 21 is convex inward from the edges of 13ab and 13cb. In the vacuum tube 90, the ship is straight to the z-cypress and faces each other along the γ axis, as shown in Figure 丨. The flange 21 is approximately integrally formed with the hollow body 13 by a bending process. Therefore, the edge 21 and the hollow body 1 3 are made of the same magnetic metal. Unlike the flange 11 of the first embodiment, the flange 21 extends over the entire 13ab and Ucd edges, respectively. Because the second embodiment omits the flange. 5. Description of the Invention (11) 1 3cd edge. Fig. 3 uses an internal magnetic shield 20 according to a second embodiment. The shield 20 has a pair of magnetic flanges 21 and 13c fixed to the hollow body 13 and the opening 13f. The pair of flanges 11 are in a vacuum tube 90. The " electron beam path protrudes inward toward each other. The pair of flanges 2 丨 protrudes vertically along the γ axis and extends flatly °. Therefore, the deflection magnetic field generated by the deflection 4 and 88 in the vacuum tube 90 to scan the electron beam 86 Will be attracted towards the pair of flanges 21. Therefore, the magnetic field expands along the longitudinal axis (z-axis) of the vacuum tube 90. As a result, the pin pad distortion or barrel grating distortion in the upper and lower areas of the screen in the same manner as the shield of the first embodiment can be effectively corrected without causing the pair of flanges 21 to contact the inner wall of the vacuum tube 90. . In addition, because the height Η and length L of the flange 21 can be set freely, the pin cushion distortion or barrel grating distortion and convergence error can be effectively corrected by appropriately designing the height Η and length L of the flange 21. In order to confirm the advantages of the present invention, the inventors performed the following tests on a color CRT. The test results are as follows. The height η of the flange 21 of the shield 20 is set to 5 mm and 10 mm. The height of the control group is set to 0 mm, which means that the flange 21 is omitted. In this case, compared with the control group, the grating distortion at the upper and lower end regions of the screen is deflected toward the pincushion shape by 0.6mm and 0.8mm in the two cases of H = 5mni and i〇mm, respectively. At the same time, the vertical convergence of the lead in the upper and lower areas of the screen will also change. In particular, the convergence of the red vertical line is biased toward the right side of the screen relative to the blue vertical line, respectively. 〇 8 nrn and 0 · 13mm 〇 Therefore, using the CRT of the internal shield 2 of the second embodiment, it is possible to improve

Page 16 V. Description of the invention (12)-Correction level of pin-up or barrel-shaped thumb distortion and correction of convergence error. Third Embodiment of the Cover FIG. 4 shows a color CRT internal magnetic shield 30 according to a third embodiment of the present invention. The mask 30 is equivalent to the case where the mask 20 changes the shape of the flange 21 in the second embodiment of FIG. The CRT of the third embodiment has the same structure as the CRT 80 except that the masker 30 is replaced by the masker 30. Therefore, for the sake of simplicity, the explanation of the same structure is omitted in Fig. 4 and the same reference numerals are used to denote the same parts as the first embodiment. As shown in Fig. 4, the internal magnetic shield 30 has a pair of flat flanges 3, which protrude from the upper sides 13ab and 13cb of the side plates 13a and 13c, respectively. The flange 31 covers the upper opening 1 3f (Z-axis) protruding toward the longitudinal axis of the hollow body 13, in other words, the flange 31 is convex inward from the edges of 13ab and 13cb. In the vacuum tube 90, the flanges 31 are approximately perpendicular to the Z axis and opposed to each other along the Y axis, as shown in FIG. The flange 31 is integrally formed with the hollow body 3 by a bending process. Therefore, the flange 31 and the hollow body 1 3 are also made of the same magnetic metal. Like the flange 21 of the second embodiment, the flange 31 extends the entire edges of 3ab and 1cd, respectively. This is because the third embodiment omits the flanges 14a, 14b, 14a ', and 14b'b, so the flange 31 can easily extend over the entire edges of 3ab and 1cd. As shown in FIG. 4 ', the shape of the flange 31 is an approximately circular segment. Therefore, the protruding height Η of the flange 31 is maximum in the middle and gradually decreases to zero toward both ends. The color CRT of the internal magnetic shield 30 of the third embodiment of FIG. 4 is used, as in the second embodiment of FIG.

Page 17 463198 V. Description of the invention (13) The grating distortion can be effectively corrected without causing the pair of flanges 31 to contact the inner wall of the vacuum tube 90. Moreover, convergence errors can also be corrected. According to the test by the inventors on a 17-inch color CRT using the internal magnetic shield 30 of FIG. 4. The test results are as follows. 7mm。 When the maximum height of the flange 31 of the shield 30 is set to 5mm, compared with the control group of H = Omni, the grating distortion in the upper and lower end regions of the screen is biased to a pin cushion shape 0.7mm. At the same time, the vertical line of sight in the upper and lower areas of the screen will change. In particular, the convergence of the blue plumb line is biased to the right of the screen by 0.15min relative to the red plumb line. Since the internal magnetic shield 30 has a flange 31 in the shape of a circular portion, it has an effect different from that of the shield 20 of the second embodiment. D The above test results are compared with the test results of the second embodiment H = 5mm. The deviation value of the pad distortion or the barrel-shaped thumb distortion is 0.7 nm ', which is equivalent to 0.6 nm in the second embodiment]. Relatively, the "convergence deviation value" is 0.5 mm, which is significantly different from 0.08 mm in the second embodiment. Therefore, the following factors can be found. H The shield 30 of the third embodiment can adjust the height of the flange 31 to increase the bias of convergence when the pin pad distortion or barrel grating distortion is controlled to change. In other words, distortion or barrel raster distortion is used when correcting the convergence error.

Circle 5 is a case where the shutter 40 of the fourth embodiment of the present invention corresponds to the second embodiment of FIG. The inner magnetic shield 40 of the fourth embodiment is divided by the color CRT. The shield 2 in the screen changed the shape of the flange 2 1 The shield 10 was replaced by the shield 40

463 ΐ 98 V. Description of the invention (14)

Others have the same structure as the CRT 80. Therefore, the explanation of FIG. 5 with the same structure is omitted, and the same reference numerals are used to save the same parts of the embodiment for the sake of simplicity. & Representation and First As shown in Fig. 5, the internal magnetic shield 40 has a pair of flat plates protruding from the upper sides 13a and 13a of the side plates 13a and 13c. The convex flanges 41 are respectively the upper openings 13 "2 of the longitudinal axis of the hollow body 13", in other words, 2 [= 2 to the edges of 13ab and 13cb are convex inward. In the vacuum tube 90, 'due to the Z axis and along the The γ axes are opposite to each other, as shown in Figure 1. ', 41 are approximately vertical like the flange 21 of the second embodiment, and the flange 41 extends the entire edge of Η and 13cd, respectively. The flange 41 and the hollow body 13 are formed by a bending process — therefore, The flange 41 and the hollow body 13 are made of the same magnetic metal. As shown in FIG. 5, the shape of the flange 41 is approximately a square with a v-shaped groove in the middle. The degree of closeness to the end point uses the color CRT of the internal magnetic shield 40 of the fourth embodiment of FIG. 5, as in the second embodiment of FIG. Ground correction without causing the pair of flanges 4 to contact the inner wall of the vacuum tube 90. Moreover, the convergence error can also be corrected. According to the inventor's test on 17 color CRTs using the internal magnetic shield 40 of FIG. The test results are as follows. Because the shape of the flange 41 and the different heights η 1 and H2 are on the screen Pin cushion distortion or end region of the barrel while the barrel deflecting raster distortion, convergence of the blue vertical line to this mode change with respect to the red vertical line toward the right edge of the screen 0

Page 19 46319ft V. Description of the invention (15) This is because of the following reasons because the deflection magnetic field attracted by the pair of flanges 41 is biased toward the pair of flanges 41 in the same manner as in the first embodiment. The sensitivity of the electron beam 86 is reduced. At the same time, the distortion of the deflection magnetic grating is reduced. At the end of the vertical axis at the center of the screen, it is true that the convergence of the pin cushion is biased compared to the omission of the flange 41. Its blue plumb line is relative to red. On the other hand, the height H2 on the diagonal of the screen is greater than the height H1 in the middle It will be larger than the wrong straight axis distortion near the center of the screen or the barrel raster distortion will be biased towards the barrel. The red lead straight line at the end of the screen's central sleeve will be biased to the right of the screen. As described above, with the fourth embodiment or the barrel grating distortion will be biased toward the third figure. In other words, the grating distortion is extremely different from the receiver. The deflection magnetic field produced by the deflection yoke 88 in the empty tube 90 in the vicinity of the flange 41 expands in the Z axis (the deflection level of the panel 82, that is, the component of the deflection field causes pin cushion distortion or barrel near 'pincushion distortion Or the barrel grating is distorted. At the same time, change the color error straight line to the right of the screen in this way. Near the end point, at the end point of the flange 41. Therefore, the deflection sensitivity is reduced near the near end point. Therefore, the entire pincushion shape. In this way, change the blue lead straight line relative to the CRT of the shield 40, the pin pad distortion is the opposite direction of the embodiment 1. In other words, the extremely poor convergence is the same as the fifth embodiment of the second embodiment.

463198 V. Description of the invention (16) The shield 50 is equivalent to the case where the shield 20 changes the shape of the flange 21 in the second embodiment of FIG. The CRT of the fifth embodiment has the same structure as the CRT 80 except that the masker 5 is used instead of the masker 0. Therefore, for the sake of simplicity, the explanation of the same structure is omitted in Fig. 6 and the same reference numerals are used to denote the same parts as the first embodiment. As shown in Fig. 6, the inner magnetic shield 50 has a pair of flat plate-shaped flanges 51 protruding from the upper sides 13ab and 13cb of the side plates 13a and 13c, respectively. The flange covers the upper opening i3f (Z axis) of the longitudinal axis of the convex hollow body 13, in other words, the & edge 51 is convex inward by the edges of 13ab and l3cb. In the vacuum tube 90, the flanges 51 are approximately perpendicular to the Z axis and face each other along the Y axis, as shown in FIG. The flanges 21 'of the second embodiment of the stripe 2 respectively extend the entire 13 so that, like the edge 51 and the hollow body 13, the shape of the edge 51 is approximately trapezoidal. Therefore, the interval H1 of the flange 51 in the middle and the heights H2, H1 near the end points are larger. Using the internal magnetic shield 5 of the fifth embodiment of FIG. 6 and the second embodiment of FIG. 2, the = CRT 'in the upper and lower end regions of the glory' can be effectively corrected without the grating distortion / 甬 'of the vacuum tube 90 Inner wall. Moreover, the convergence error also touches the area ηι '° η2 at the edge 51, and changes in the upper and lower ends of the screen. It is biased toward the edge and at this time. This is for the following reasons. The color straight line deviates to the right of the screen because the pair of flanges 51 are attracted by the deflection magnets in the vacuum tube 90.

Page 21

4 63 1 1B

The generated deflection magnetic field A is extended with the deflection magnetic field in the vicinity of the flange 5 丨 of the first embodiment, and the low-electron Γ′ΓΓΓΓΠζ axis is extended. The extension of the magnetic field is reduced. The tomb of You Xin is weakened by the amount of pin cushion distortion or barrel grating distortion. „Near the end point of the central vertical axis, because the deflection magnetic field component reduces the distortion of the thumb compared with the omission of the flange 51, the color lead line is biased to the right of the screen. On the other hand, near the end of the diagonal of the screen, the convex The edge H1 of the edge 5 1 is smaller than the height H1 in the middle. Therefore, the reduction level of the deflection sensitivity will be small = near the center of the vertical axis of the screen. As a result, the amount of deflection of the electron beam 8 6 will be greater than that of the center of the screen. Nearby β Therefore, the entire pincushion distortion or barrel grating distortion will be biased toward the pincushion shape. The convergence changed in this way will be the same as near the endpoint of the central axis of the screen, and its blue lead line will be biased to the right of the screen relative to the red lead line. For a CRT with a masker 50 of the fifth embodiment, pin cushion distortion or barrel grating distortion will be biased in the opposite direction of the fourth embodiment of Figure 5. In other words, the pole of the grating distortion is relative to the pole of the convergence error and the fourth Sixth Embodiment FIG. 7 is a color CRT internal magnetic shield 60 in a sixth embodiment of the present invention. The shield 60 is equivalent to the shield 20 in the second embodiment of FIG. 3 and the shape of the flange 21 is changed. In the CRT of the sixth embodiment, except that the masker is used instead of the masker 10

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V. Description of Invention Except (18), it has the same structure as CRT 80. Fig. 7 is explained with slightly the same structure and the same ^ is used, and the same parts of the embodiment are omitted for simplicity. The test symbol is used to indicate the first as shown in Figure 7. The internal magnetic shield 60 has a flat body flange 6 1 drawn from the upper side of the side plates 1 3a and 1 3c and the flat flange 6 1 respectively. = 3 =. Convex _ cover the convex _ and _ edge inward. In the true axis, the tube is wide: The flange 61 is due to Z # and faces each other along the Υ axis, such as m. +, The flange 61 is approximately vertical, and the 13cd 2 = 1 embodiment of the flange 21 ′ The flange 61 extends the entire 13ab, respectively. Therefore, the flange 61 and the center 13 are formed of a private body and a hollow body 13-. As shown in Fig. 7, several C-shaped bodies are made of the same magnetic metal. 6〗; SI: Yes, Figure 2: The first two real color = = 6 ° colored ⑽, like the inner wall of the vacuum tube 90. it ”: This pair of flanges 61 will not cause the pair of flanges 61 to contact Λ and 'convergence errors can be corrected. Or barrel-shaped I-Fifth embodiment' Acupuncture distortion in the lower area of the f-screen is converged and will be biased towards the pin cushion The 1-color lead line changed in this way is biased toward the right side of the screen relative to the red lead line. Sn know Rn The first to sixth embodiments, flange pair 10, 20 '30, 40, plate #bismuth hollow body 13 It is formed integrally. Therefore, it can be formed only by complimenting the flat plate I material of the hollow body 13, which can increase the yield and reduce the manufacturing cost. The 23rd stomach 463 1 9 '

Seventh Embodiment Fig. 8 shows a color cr r τ internal magnetic shield 70 according to a seventh embodiment of the present invention. The shield 70 is equivalent to the shield 丨 0 in the second embodiment of FIG. 3 except that the flange pair 2 is replaced by a pair or edge 71. The seventh embodiment. r τ has the same structure as the CRT 80 except that the shield 10 is replaced by the shield 60. Therefore, for the sake of simplicity, the explanation of the same structure is omitted in Fig. 8 and the same reference numerals are used to denote the same parts as the first embodiment. As shown in Fig. 8 ', the internal magnetic shield 70 has a pair of rectangular flat plate-shaped flanges Π protruding from the upper sides 13ab and 13cb of the side plates 13a and 13c, respectively. The flange 71 covers the upper opening 13f (z-axis) protruding toward the longitudinal axis of the hollow body 13, in other words, the flange 71 is convex inward from the edges of 13ab and 13cb. In the vacuum tube 90, the flanges 71 are approximately straight along the Z axis and face each other along the Y axis, as shown in FIG. Like the flange 21 of the second embodiment, the flange 71 extends the entire Uab and 13cd edges, respectively. The flange 71 is formed separately from the side plates 13a'13b, 13c, and 13d and then fixed to the inner walls of the side plates 1 3a and 1 3b, respectively. The flange 7 1 and the hollow body 1 3 are also made of the same magnetic metal. Using the color CRT of the internal magnetic shield 70 of the seventh embodiment of FIG. 8, as in the second embodiment of FIG. 2, pin cushion distortion or barrel grating distortion in the upper and lower end regions of the screen can be effectively corrected without causing the problem. The opposing flange 71 contacts the inner wall of the vacuum tube 90. Moreover, convergence errors can also be corrected. Unlike the second embodiment of FIG. 3, the flange 71 is formed separately from the side plates 丨 3a, 1 3b, 1 3c, and 1 3d and then fixed to the inner walls of the side plates 丨 仏 and 丨 ⑽, respectively. Therefore, there must be a step of fixing to the side plates 13a and 13b. However, the advantage is that the position of the flange 71 can be adjusted along the longitudinal axis of the CRT (2 axis

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d 63 1 9B V. Description of the invention (20)) ’, and can finely adjust the correction level or pin cushion distortion or barrel grating distortion. Although the flange 71 of the seventh embodiment is rectangular, it may be any other shape of the third to sixth embodiments. The shape of the flange 71 can be any complicated shape such as a curved strip. Therefore, the amount of correction level or pincushion distortion or barrel grating distortion can be corrected more effectively. +. Although the present invention is directed to the color CRTs of the first to seventh embodiments described above, 'it may be applied to a monochrome CRT. The flange of the internal magnetic shield can be any of the other figures 2 to 8. Patent: The present invention is clearly and completely disclosed for a specific embodiment, and the application 1 is not limited to the embodiment. Any person skilled in the art can easily achieve it. 1 Disaster

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A 63 1 9B Brief Description of Drawings Figure 1 is a schematic cross-sectional view of a color CRT structure according to the first embodiment of the present invention; Figure 2 is a schematic diagram of the detailed structure of the internal magnetic shield of the CRT according to the first embodiment of FIG. 1 3 is a schematic perspective view of the detailed structure of the internal magnetic shield of the color CRT according to the second embodiment of the present invention; FIG. 4 is a schematic perspective view of the detailed structure of the internal magnetic shield of the color CRT according to the third embodiment of the present invention; 5 is a schematic perspective view of a detailed structure of an internal magnetic shield of a color CRT according to a fourth embodiment of the present invention; FIG. 6 is a schematic perspective view of a detailed structure of an internal magnetic shield of a color CRT according to a fifth embodiment of the present invention; FIG. 8 is a schematic perspective view of the detailed structure of the internal magnetic shield of the color CRT according to the sixth embodiment of the present invention; FIG. 8 is a schematic perspective view of the detailed structure of the internal magnetic shield of the color CRT according to the seventh embodiment of the present invention.

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Claims (1)

d 63 1 98 6. Scope of patent application 1. A cathode ray tube having: (a) a vacuum tube housing; the housing has a panel and an electron gun inside; the housing has an electron passed through the electron beam emitted by the electron beam Beam path; and (b)-an internal magnetic shield located between the panel and the electron gun in the housing; the shield has a hollow body with a substantially quadrangular pyramid shape and a pair of flanges; the hollow body has a The first opening is located on the electronic grabbing side and a second opening is located on the panel side; the hollow body surrounds the path; the electron beam passes through the first opening, the inside of the hollow body, and the second opening to the panel; the pair of convex The edge is fixed at a position where the hollow body is close to the first opening; the pair of flanges protrude inwardly and face each other across the path; one of the deflection magnetic fields generated in the shell is attracted toward the pair of flanges. 2. The cathode ray tube of item 1 of the patent application scope, wherein the pair of flanges extend along the vertical axis of the housing and straighten the vertical axis; wherein the deflection magnetic field attracted toward the pair of flanges is mainly a vertical deflection Its magnetic field. 3. The cathode ray tube according to item 1 of the application, wherein the pair of flanges Page 27 4 63 1 Ή 6. The protruding height of the patent application scope changes along the extension direction of the pair of flanges. 4 · The cathode ray tube according to item 1 of the scope of the patent application, wherein the shape of the pair of flanges is selected from the group consisting of a square, a trapezoid, a circular segment], or a triangle. 5. The cathode ray tube according to item 1 of the application, wherein the pair of flanges are formed integrally with the hollow body of the shield. 6. The cathode ray tube according to item 1 of the application, wherein the pair of flanges are formed separately from the hollow body of the shield and then fixed to the hollow body. 7. An internal magnetic shield for a cathode ray tube, having: (a) a hollow body with a slightly quadrangular truncated cone shape; the hollow body having a first opening on the electron gun side and a second opening on the Panel side; the hollow body surrounds the path; the electron beam emitted by the electron gun will pass through the first opening, the interior of the hollow body, and the second opening to the panel; (b)-a pair of flanges, fixed at A position of the hollow body close to the first opening; the pair of flanges protruding inwardly facing each other across the path; wherein a deflection magnetic field in the housing is attracted toward the pair of flanges. Page 28