JP2005285751A - Cathode ray tube device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To emphasize magnetic field of a velocity modulation coil without disturbing magnetic field of a magnet ring of a CPU. <P>SOLUTION: A plurality of magnet rings 13A, 13B, 14, 15 for compensating convergence are arranged in the direction of pipe axis interposing spacers 16, 17, 18 on an outer peripheral face of a neck part 3. The velocity modulation coil 19 for modulating scanning speed in the horizontal direction of electron beam is arranged to overlap the magnet ring and a position in the direction of pipe axis. At least one of the spacers is composed of a magnetic body or at least one of the spacers is composed of a magnetic body and an outermost surface in the radial direction of the spacer composed of the magnetic body is covered with a non-metallic material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cathode ray tube apparatus.

  In recent years, with the increase in size of television receivers and the like, higher image quality has been demanded. As one technique for this purpose, a cathode ray tube device equipped with a velocity modulation coil has been devised in order to emphasize the contour of an image and sharpen the image quality. The velocity modulation coil forms a magnetic field in the vertical scanning direction of the electron beam and changes the scanning speed of the electron beam in the horizontal scanning direction to enhance the contour of the image (see, for example, Patent Document 1).

Further, Patent Document 2 describes that a pair of ferromagnetic materials are disposed on the outer peripheral surface of the neck portion of the funnel so as to be paired with a pair of loop coils of the velocity modulation coil. According to this, since the magnetic field generated by the speed modulation coil can be strengthened by the ferromagnetic material and concentrated on the electron beam, the speed modulation effect can be improved.
Japanese Utility Model Publication No.57-45650 JP 2003-1116019 A

  On the other hand, a typical color cathode ray tube apparatus generally includes a deflection yoke and a CPU (Convergence and Purity Unit). The CPU is provided with 2-pole, 4-pole, and 6-pole magnet rings that apply a magnetic field to the electron beam, and is mounted on the outer peripheral surface of the neck portion of the funnel in which the electron gun is built.

  When a speed modulation coil, a ferromagnetic material that strengthens and concentrates this magnetic field, and a CPU are mounted on the outer peripheral surface of the neck portion of the funnel, a ferromagnetic material is conventionally arranged in the opening of the loop coil of the speed modulation coil. However, a CPU magnet ring is arranged so as to cover them. Therefore, when viewed from the direction orthogonal to the tube axis, the ferromagnetic material and the CPU magnet ring overlap each other. As a result, the magnetic field generated by the magnet ring of the CPU becomes non-uniform due to the influence of the ferromagnetic material arranged on the inside thereof, and there is a problem that the convergence correction effect by the CPU cannot be obtained sufficiently.

  The present invention solves the above-mentioned problems in the conventional cathode ray tube device, and can emphasize the magnetic field of the speed modulation coil without disturbing the magnetic field of the magnet ring of the CPU, and as a result, the cathode ray capable of displaying good image quality. An object is to provide a pipe device.

  A cathode ray tube device according to the present invention includes a face portion having a phosphor screen formed on an inner surface, a funnel portion joined to the face portion, an electron gun housed in a neck portion of the funnel portion, and a funnel portion A deflection yoke that is provided on the outer peripheral surface and deflects the electron beam emitted from the electron gun in the horizontal direction and the vertical direction, and for correcting the convergence disposed on the outer peripheral surface of the neck portion in the tube axis direction. A plurality of magnet rings, at least one or more spacers disposed between the magnet rings disposed in the tube axis direction, and the magnet rings and the positions in the tube axis direction overlapping with each other, and the electron beam And a velocity modulation coil for modulating the horizontal scanning velocity.

  The first cathode ray tube device is characterized in that, in the above, at least one of the spacers is made of only a magnetic material.

  In the second cathode ray tube apparatus, in the above, at least one of the spacers is made of a magnetic material, and the outermost surface in the radial direction of the spacer made of the magnetic material is covered with a nonmetallic material. Features.

  According to the first and second cathode ray tube apparatuses of the present invention, since the magnetic spacer is disposed between the CPU magnet ring and the magnet ring, the magnetic field of the CPU magnet ring is not disturbed. In addition, the magnetic flux density of the speed modulation coil can be increased and the speed modulation sensitivity can be improved without increasing the number of parts. Therefore, the image quality can be remarkably improved. Further, since the spacer made of a magnetic material does not affect the convergence correction work performed by adjusting the rotation phase of the magnet ring, good convergence can be easily obtained using the magnet ring.

  Further, in the first cathode ray tube apparatus, since at least one of the spacers is made of only a magnetic material, the spacer can be produced at a low cost.

  Further, in the second cathode ray tube apparatus, since the outermost surface in the radial direction of the spacer made of a magnetic material is covered with a non-metallic material, the spacer can be prevented from cracking, and even if it is cracked, its shape is changed. You can keep holding.

  In the first and second cathode ray tube apparatuses of the present invention, the spacer made of a magnetic material is preferably annular. As a result, the spacer can be mounted without considering the phase around the tube axis, and the effect of improving the magnetic flux density of the speed modulation coil can always be obtained stably regardless of the phase around the tube axis.

  The magnetic body is preferably a sintered body of Mg—Zn ferrite. Thereby, magnetic flux density can be improved efficiently.

  It is preferable to have three or more sets of the magnet rings and a plurality of the spacers made of a magnetic material. As the number of magnetic spacers increases, the effect of improving the magnetic flux density of the speed modulation coil increases, and the image quality can be improved.

  The position of the spacer made of a magnetic material in the tube axis direction coincides with the position in the tube axis direction of the gap between two electrodes arranged apart from each other in the tube axis direction, which forms the main lens in the electron gun. Preferably it is. Thereby, the loss of the magnetic field of the speed modulation coil can be reduced.

  The spacer made of a magnetic material preferably has a thickness of 2 mm to 5 mm. If the thickness is less than 2 mm, the effect of improving the magnetic flux density of the speed modulation coil is reduced. On the other hand, if the thickness exceeds 5 mm, the CPU axial dimension increases.

  Hereinafter, the present invention will be described with reference to embodiments.

  FIG. 1 is a half sectional view showing a schematic configuration of a cathode ray tube apparatus according to an embodiment of the present invention. As shown in FIG. 1, the cathode ray tube device of the present embodiment is the face part 1 having a phosphor screen 1 </ b> A formed on the inner surface, the funnel part 2 joined to the face part 1, and the finest details of the funnel part 2. A cathode ray tube having a neck portion 3, a deflection yoke 4 for deflecting an electron beam provided on an outer peripheral surface of a portion from the funnel portion 2 to the neck portion 3, and a tip side of the neck portion 3 thereby. The CPU 5 corrects the convergence. An electron gun 6 is provided in the neck portion 3.

  The deflection yoke 4 deflects the three electron beams emitted from the electron gun 6 vertically and horizontally, and scans the phosphor screen 1A. The deflection yoke 4 includes a horizontal deflection coil 41, a vertical deflection coil 42, and a ferrite core 43. A resin insulating frame 44 is provided between the horizontal deflection coil 41 and the vertical deflection coil 42. The insulating frame 44 maintains an electrical insulation state between the horizontal deflection coil 41 and the vertical deflection coil 42 and plays a role of supporting both the deflection coils 41 and 42.

  FIG. 2 is an enlarged cross-sectional view near the neck portion 3. The electron gun 6 mainly includes three cathodes 7, a control electrode 8, acceleration electrodes 9A and 9B, focusing electrodes 10A, 10B, and 10C, and an anode 11. Reference numeral 22 denotes a shield cup joined to the anode 11. By applying a predetermined voltage to each electrode, the main lens 12 is formed in the vicinity between the focusing electrode 10C and the anode 11, and a good focus can be obtained in the phosphor screen 1A.

  The CPU 5 includes a two-pole magnet ring 13A for adjusting purity, a two-pole magnet ring 13B for adjusting raster distortion, a four-pole magnet ring 14 and a six-pole magnet ring 15 for adjusting convergence, And annular spacers 16, 17, 18. The spacers 16, 17, and 18 secure a distance between adjacent magnet rings, in other words, fill a gap between adjacent magnet rings. The magnet rings 13 </ b> A, 13 </ b> B, 14, 15 and the spacers 16, 17, 18 are externally inserted and held in a substantially cylindrical resin frame 20 fixed on the outer peripheral surface of the neck portion 3. Each of the magnet rings 13A, 13B, 14, and 15 is made of a pair of annular magnetic bodies, and as shown in the drawing, the two-pole magnet ring for purity adjustment from the deflection yoke 4 side toward the end portion side of the neck portion 3. 13A, raster distortion adjusting two-pole magnet ring 13B, convergence adjusting four-pole magnet ring 14, and convergence adjusting six-pole magnet ring 15 are arranged in this order. A spacer 16 is provided between the 2-pole magnet ring 13A and the 2-pole magnet ring 13B, and a spacer 17 is provided between the 2-pole magnet ring 13B and the 4-pole magnet ring 14, and the 4-pole magnet ring 14 and the 6-pole magnet ring 15 are provided. The spacers 18 are arranged in close contact with the magnet rings so as to fill the space between the magnet rings.

  Reference numeral 19 denotes a velocity modulation coil 19 for performing image edge enhancement. The speed modulation coil 19 includes a pair of loop coils 19A and 19B, and is held by the resin frame 20 so as to face each other in the vertical direction.

  3A is a perspective view showing a schematic configuration of the speed modulation coil 19, and FIG. 3B is a front view of the speed modulation coil 19 as seen from the arrow 3B along the tube axis shown in FIG. 3A. FIG. 3C is a development view in which loop coils 19A and 19B constituting the speed modulation coil 19 are developed on a plane.

  An embodiment of the velocity modulation coil 19 is shown. The coils 19A and 19B are formed by winding a copper wire having a strand diameter of 0.4 mm, which is covered with polyurethane, into a substantially square shape, and as shown in FIG. It is curved so as to follow the outer peripheral shape, and is arranged facing the vertical direction. The dimensions of the substantially rectangular coils 19A and 19B are as follows. The length L1 of the side arranged substantially parallel to the tube axis direction is 25 mm and the width W1 is 35 mm, as shown in FIG. 3C. It is. As shown in FIG. 3B, the sides having the width W1 are curved and deformed along the virtual cylindrical surface having a diameter D1 = 33 mm, and the coils 19A and 19B are mounted on the resin frame 20. At this time, the width W2 of the coils 19A and 19B in the horizontal direction orthogonal to the tube axis shown in FIG. 3B is 30 mm. D2 is the outer diameter of the neck portion 3, and D1> D2. A current corresponding to the speed modulation signal obtained by differentiating the video signal is applied to the speed modulation coil 19.

  As shown in FIG. 2, the velocity modulation coil 19 and the magnet rings 13 </ b> A, 13 </ b> B, 14, 15 constituting the CPU 5 are arranged so that their positions in the tube axis direction overlap each other. The dipole magnet ring 13A is disposed at substantially the same position as the main lens 12 in the tube axis direction in order to suppress focus deterioration due to purity correction. In order to effectively apply the magnetic field generated from the velocity modulation coil 19 to the electron beam, the magnetic field generated from the velocity modulation coil 19 is concentrated in the gap between the focusing electrode 10C forming the main lens 12 and the anode 11. It is preferable. Therefore, among the spacers 16, 17, and 18, the spacer 16 disposed between the two sets of two-pole magnet rings 13A and 13B and disposed closest to the two-pole magnet ring 13A is made of a magnetic material. In one embodiment, a sintered body of Mg—Zn ferrite, which is a magnetic material, can be used as the spacer 16. The other spacers 17 and 18 are made of resin. The inner diameter of the spacer 16 is 33 mm, the same as the inner diameter of the dipole magnet ring 13A, the outer diameter is 44 mm, and the thickness (dimension in the tube axis direction) is 3 mm.

  In order to effectively apply the magnetic field generated from the velocity modulation coil 19 to the electron beam, the smaller the inner diameter, the larger the outer diameter, and the thicker the spacer 16 made of a magnetic material is better. However, in general, the dimensions are often determined due to location restrictions. If the spacer 16 made of a magnetic material is too thin, the magnetic material is easily broken, and the speed modulation sensitivity is deteriorated. Therefore, the thickness is preferably 2 mm or more. However, since the dimension of the CPU 5 in the tube axis direction becomes large if it is too thick, it is generally preferably 5 mm or less.

  By using the magnetic spacer 16, the density of magnetic flux acting on the electron beam in the neck portion 3 can be increased. This will be described with reference to the drawings. 4A shows the magnetic flux when all the spacers are made of resin, and FIG. 4B shows the magnetic flux when the magnetic spacer 16 is provided. 4 (A) and 4 (B) both schematically show the magnetic flux in a plane perpendicular to the tube axis that intersects the velocity modulation coil 19. As can be seen from FIGS. 4A and 4B, when the magnetic spacer 16 is used, a magnetic flux is generated in the inner region of the magnetic spacer 16 (the electron beam passage region in the neck portion 3) due to the cored effect. Since it concentrates, the density of the magnetic flux which acts on an electron beam becomes high. In addition, since the spacer 16 is provided in substantially the same position as the gap between the focusing electrode 10C forming the main lens 12 and the anode 11 in the electron gun 6 in the tube axis direction, the influence of eddy current loss on the electrode is exerted. Can be avoided as much as possible, and the magnetic field region can be widened. Therefore, the sensitivity of speed modulation can be improved effectively.

  The magnetic flux density distribution from the vicinity of the focusing electrode 10B to the vicinity of the shield cup 22 along the tube axis at the center of the neck portion 3 will be described with reference to FIG. 5A is a cross-sectional view of the neck portion 3 along the tube axis, and FIG. 5B is a result of measuring the magnetic flux density change along the tube axis (Z axis) when all spacers are made of resin. FIG. 5C is a diagram showing the result of measuring the change in magnetic flux density along the tube axis (Z axis) when the spacer 16 made of a magnetic material is used. From FIG. 5B and FIG. 5C, it can be seen that the magnetic flux density in the vicinity of the main lens is approximately doubled by using the magnetic spacer 16.

  Next, experimental results confirming the effects of the present invention will be described. A cathode ray tube device (product of the present invention) according to the present invention was actually manufactured and the velocity modulation sensitivity was confirmed. For comparison, the speed modulation sensitivity of the same cathode ray tube apparatus (conventional product) as that of the present invention was confirmed except that the spacers of the CPU 5 were all made of resin. FIG. 6 is a graph showing experimental results of velocity modulation sensitivity. In FIG. 6, the horizontal axis indicates the frequency of the speed modulation signal applied to the speed modulation coil 19. The modulation effect index on the vertical axis is the 5% luminance diameter in the central portion of the phosphor screen (an electron beam obtained by removing a portion of 5% or less from the minimum luminance when the luminance peak of the electron beam spot is 100%) The displacement in the horizontal direction of the electron beam spot having a (spot diameter of 2) is relatively expressed with the measured value of the conventional product when the velocity modulation frequency is 1 MHz as 100%. Larger values indicate better speed modulation sensitivity and improved image quality. In the experiment, the energization amount to the speed modulation coil 19 was constant at 0.8A. As shown in FIG. 6, the speed modulation sensitivity of the product of the present invention is approximately 1.5 times that of the conventional product regardless of the speed modulation frequency. Actually, the present invention product and the conventional cathode ray tube device were incorporated into the TV set, and the practical image quality was compared. The TV set using the cathode ray tube device of the present invention used the conventional cathode ray tube device. The image quality was significantly improved compared to the TV set.

  In addition, a cathode ray tube device described in the above-mentioned Patent Document 2 in which a pair of ferromagnets are arranged opposite to each other in the vertical direction with an electron beam sandwiched between outer surfaces of a neck portion of the cathode ray tube is manufactured. The workability of the convergence correction by the inventive cathode ray tube apparatus and the CPU was compared. In the cathode ray tube device described in Patent Document 2, the CPU magnet ring and the ferromagnetic material overlap each other when viewed from the direction orthogonal to the tube axis, so that the magnetic field from the quadrupole and hexapole magnet rings is generated. There was a case where the convergence correction was not possible. In contrast, in the cathode ray tube device of the present invention, the CPU magnet ring and the magnetic spacer 16 do not overlap when viewed in a direction perpendicular to the tube axis. It was distributed evenly and the convergence correction was easy. On average, the convergence adjustment time required for one cathode ray tube device was about half that of the cathode ray tube device described in Patent Document 2 in the cathode ray tube device of the present invention.

  Further, in the cathode ray tube device described in Patent Document 2, since it is necessary to add a pair of ferromagnetic materials to the neck portion, the number of parts and the number of assembling steps are increased and the cost is increased. Compared to this, the cathode ray tube device of the present invention uses only magnetic spacers instead of resin spacers. Therefore, compared with the cathode ray tube device described in Patent Document 2, a pair of strong tubes is used. It is possible to reduce the number of two parts corresponding to the magnetic body, and there is a merit in terms of cost.

  In the above embodiment, the resin frame 20 holding the CPU 5 and the deflection yoke 4 are separated. However, the present invention is not limited to this, and the insulating frame of the resin frame 20 and the deflection yoke 4 is shown. 44 may be integrated.

  In the above embodiment, of the three spacers 16, 17, and 18 of the CPU 5, only the spacer 16 is made of a magnetic material. However, the present invention is not limited to this, and the spacer 17 and / or the spacer 18 is made of a magnetic material. It may be. As the number of spacers made of a magnetic material increases, the magnetic flux density of the speed modulation coil 19 can be further increased, and the speed modulation sensitivity is further improved. The spacer 16 may be made of resin, and at least one or more other spacers may be made of a magnetic material.

  Further, by using a magnetic spacer, it is possible to prevent the magnetic field of the deflection yoke 4 from leaking to the electron gun 6 side. Accordingly, since the electron beam is not preliminarily deflected by the leakage magnetic field from the deflection yoke 4 before passing through the main lens 20, the focus around the face portion 1 is improved.

  In the above embodiment, the sintered body of Mg—Zn ferrite is exemplified as a specific example of the magnetic body used for the spacer made of the magnetic body. However, the present invention is not limited to this. For example, the sintered body of Mn—Zn ferrite is used. A sintered body of Ni-Zn ferrite can also be used.

  In the above-described embodiment, an example in which the spacer 16 is made of only a magnetic material, that is, an example in which the magnetic material is exposed on all outer surfaces of the spacer has been described, but the present invention is not limited to this. For example, as shown in FIG. 7, the outer surface of the spacer 16 made of a magnetic material intersecting the surface perpendicular to the tube axis (the surface facing away from the tube axis, that is, the outermost surface of the spacer 16 in the radial direction). The surface) may be covered with a nonmetallic material 25. Thereby, the spacer 16 becomes difficult to break. Further, even if the spacer 16 made of a magnetic material is broken after the CPU 5 is mounted on the cathode ray tube, since the entire surface of the magnetic material is in contact with any member, the shape does not collapse. The desired effect of increasing the density and improving the speed modulation sensitivity can be obtained. Examples of the non-metallic material 25 include a non-metallic tape wound around and adhered to the outer surface of the spacer 16, a resin formed by integral molding with the spacer 16 so as to cover the outer surface of the spacer 16, and the CPU 5 as a cathode ray. An example is a flame retardant adhesive applied so as to cover the outer surface of the spacer 16 after being attached to the tube.

  The field of application of the cathode ray tube device of the present invention is not particularly limited, and can be used widely as a color picture tube device such as a television or a computer display.

1 is a half sectional view showing a schematic configuration of a cathode ray tube apparatus according to an embodiment of the present invention. It is an expanded sectional view near a neck part of a cathode ray tube device concerning one embodiment of the present invention. 3A is a perspective view showing a schematic configuration of the speed modulation coil, FIG. 3B is a front view of the speed modulation coil viewed from an arrow 3B along the tube axis shown in FIG. 3A, and FIG. (C) is a plane development view of the loop coil constituting the velocity modulation coil. FIG. 4A is a diagram showing the state of magnetic flux around the velocity modulation coil of a conventional cathode ray tube device in which all spacers are made of resin. FIG. 4B is a diagram showing a state of magnetic flux around the velocity modulation coil of the cathode ray tube apparatus according to one embodiment of the present invention. FIG. 5A is a cross-sectional view of the neck portion along the tube axis, and FIG. 5B shows the result of measuring the change in magnetic flux density along the tube axis (Z-axis) when all spacers are made of resin. FIG. 5C is a diagram showing a result of measuring a change in magnetic flux density along the tube axis (Z axis) when a spacer made of a magnetic material is used. It is the figure which showed the result of having measured the velocity modulation sensitivity of this invention and the conventional cathode ray tube apparatus. It is the perspective view which showed another example of the spacer which consists of a magnetic body used for the cathode ray tube apparatus which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Face part 1A ... Phosphor screen 2 ... Funnel part 3 ... Neck part 4 ... Deflection yoke 5 ... CPU
6 ... Electron gun 7 ... Cathode 8 ... Control electrodes 9A, 9B ... Accelerating electrodes 10A, 10B, 10C ... Focusing electrode 11 ... Anode 12 ... Main lens 13A ... Purity correction dipole magnet ring 13B ... Raster distortion correction dipole magnet Ring 14 ... 4 pole magnet ring 15 ... 6 pole magnet ring 16 ... Magnetic spacer 17 ... Resin spacer 18 between 2 pole magnet ring and 4 pole magnet ring ... Resin between 4 pole magnet ring and 6 pole magnet ring Spacer 19 ... Speed modulation coil 20 ... Spring 22 ... Shield cup 25 ... Non-metallic material

Claims (7)

A face part having a phosphor screen formed on the inner surface;
A funnel portion joined to the face portion;
An electron gun housed in the neck portion of the funnel portion;
A deflection yoke provided on the outer peripheral surface of the funnel portion and deflecting an electron beam emitted from the electron gun in a horizontal direction and a vertical direction;
A plurality of magnet rings arranged on the outer peripheral surface of the neck portion in the tube axis direction for correcting convergence;
At least one or more spacers disposed between the magnet rings disposed in the tube axis direction;
A cathode ray tube device comprising: a magnetism ring and a velocity modulation coil provided so as to overlap a position in a tube axis direction, and modulating a scanning velocity in a horizontal direction of the electron beam;
At least one of the spacers is made only of a magnetic material. A face part having a phosphor screen formed on the inner surface;
A funnel portion joined to the face portion;
An electron gun housed in the neck portion of the funnel portion;
A deflection yoke provided on the outer peripheral surface of the funnel portion and deflecting an electron beam emitted from the electron gun in a horizontal direction and a vertical direction;
A plurality of magnet rings arranged on the outer peripheral surface of the neck portion in the tube axis direction for correcting convergence;
At least one or more spacers disposed between the magnet rings disposed in the tube axis direction;
A cathode ray tube device comprising: a magnetism ring and a velocity modulation coil provided so as to overlap a position in a tube axis direction, and modulating a scanning velocity in a horizontal direction of the electron beam;
At least one of the spacers is made of a magnetic material, and a radially outermost surface of the spacer made of the magnetic material is covered with a nonmetallic material.   3. The cathode ray tube device according to claim 1, wherein the spacer made of a magnetic material is annular.   The cathode ray tube device according to claim 1 or 2, wherein the magnetic body is a sintered body of Mg-Zn ferrite.   The cathode ray tube apparatus according to claim 1 or 2, wherein the cathode ring tube device has three or more sets of the magnet rings and a plurality of the spacers made of a magnetic material.   The position of the spacer made of a magnetic material in the tube axis direction coincides with the position in the tube axis direction of the gap between two electrodes arranged apart from each other in the tube axis direction, which forms the main lens in the electron gun. The cathode ray tube device according to claim 1 or 2. The cathode ray tube device according to claim 1 or 2, wherein the spacer made of a magnetic material has a thickness of 2 mm to 5 mm.

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