JP2002289120A - Deflection yoke and cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke device which is capable of correcting an unsymmetrical raster distortion at top and bottom with simple mechanism certainly by permanent magnets fixed to a deflection yoke, and also provide a cathode-ray tube having excellent picture quality. SOLUTION: In this deflecting yoke, permanent magnet holding portions 35 are fixed in diametrical opposed positions at top and bottom on the larger diameter portion 27 in a cone-like separator 29, and also respective permanent magnets are held elastically in the permanent magnet holding portions 35, thence a raster distortion is corrected by adjusting respective positions of the permanent magnets 36 with respective bolts 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke device and a cathode ray tube which can be used for a display device such as a color television receiver and a color terminal display and which can correct raster distortion.

[0002]

2. Description of the Related Art Color cathode ray tubes are still widely used in display devices such as color television receivers and color terminal display devices because of their simplicity of size, high definition, and price. I have. Moreover, in these cathode ray tubes,
Recently, flat faces with flattened face surfaces of cathode ray tubes
A cathode ray tube of a rectangular shape has been adopted. Further, these display devices are required to have higher quality and higher definition, and in particular, performance such as color shift (convergence) performance and raster distortion of a screen which is found on a cathode ray tube screen. Is gaining importance. However, flat face
In a cathode ray tube, since color shift and raster distortion appear more remarkably than in a conventional cathode ray tube, improvement is particularly demanded.

In order to correct the color misregistration, the winding distribution of the horizontal deflection coil and the vertical deflection coil in the deflection yoke device, that is, the magnetic field distribution of the horizontal deflection coil is designed so that a pincushion magnetic field is generated. The magnetic field distribution of the vertical deflection coil is designed to be a barrel magnetic field, thereby improving the color shift. on the other hand,
Among the vertical and horizontal raster distortions, the left and right pincushion distortions are electrically corrected by providing a left and right pincushion distortion correction circuit, and the upper and lower pincushion distortions are corrected as much as possible by the magnetic field of the deflection yoke. Improvements are made by designing the distribution to be optimal.

However, there is a limit in correcting the upper and lower pincushion distortion only by the magnetic field distribution. Therefore, in addition to the magnetic field distribution of the deflection coil itself, a permanent magnet is added to the deflection coil to change the magnetic field distribution. By that, the upper and lower raster
The distortion is corrected.

FIG. 6 shows the structure of a conventional color cathode ray tube. This color cathode ray tube has a substantially rectangular face panel 51 and an envelope formed of a funnel-shaped funnel 52 joined to the face panel 51. Inside the face panel 51, the effective face panel 51 is provided. A shadow mask 55 in which a large number of electron beam passage holes 54 are formed is disposed to face a phosphor screen 53 formed of a three-color phosphor layer and a black non-light-emitting layer formed on the inner surface of the portion. The shadow mask 55 is welded to a mask frame 56. Further, a magnetic shield 57 is fixed to the mask frame 56 and an elastic support (not shown).
Through a stud pin (not shown) formed on the inner surface of the skirt portion of the face panel 51.

In the neck 58 of the funnel 52, an in-line type electron gun 60 for emitting three electron beams 59B, 59G and 59R is provided. The three electron beams 59B, 59G and 59 emitted from the electron gun 60 are provided. 59R is deflected by a magnetic field generated by a deflection yoke device 61 mounted on the outside of the funnel 52, and the phosphor screen 53 is horizontally and vertically scanned to reproduce and display a color image.

FIG. 7 shows the structure of a deflection yoke device 61 used in this color cathode ray tube. That is, the face panel 51 of the cathode ray tube is made of synthetic resin such as polypropylene.
Funnel-shaped separator 64 having a large-diameter portion 62 located on the side and a small-diameter portion 63 located on the electron gun 60 side of the cathode ray tube.
Are formed. Inside the separator 64, a pair of horizontal deflection coils 65 formed in a saddle shape are disposed vertically facing each other, and outside the separator 64, a pair of vertical deflection coils 66 similarly formed in a saddle shape are provided. They are arranged to face left and right. Further, a conical cylindrical core 67 made of ferrite or the like is mounted so as to cover the outer periphery of the middle part of the vertical deflection coil 66, and a terminal plate 68 is mounted near the small diameter portion 63 of the separator 64. I have.

On the other hand, a box-shaped permanent magnet holding portion 70 having an outwardly projecting opening 69 disposed on the face panel 51 side or the neck 58 side is provided above and below the periphery of the large diameter portion 62 of the separator 64. The horizontal deflection coil 65 is formed integrally with the separator 64 in a direction orthogonal to the axial direction.
For example, the upper permanent magnet holding portion 70 is magnetized so that the S pole is located on the left side and the N pole is located on the right side when viewed from the large diameter portion 62 side of the separator 64. The permanent magnet 71 is mounted on the lower permanent magnet holding portion 70 so that the north pole is on the left side in the opposite direction to the upper permanent magnet 71 and the south pole is on the right side. Magnet 7
The deflection yoke device 61 is configured by mounting the respective components 1.

The deflection yoke device 61 thus configured
According to this, the electron beams 59B, 59G, 59R of the cathode ray tube are deflected in the left-right direction by a pair of horizontal deflection coils 65, and the electron beams 59 are deflected by a pair of vertical deflection coils 66.
B, 59G and 59R are vertically deflected to display a predetermined raster on the cathode ray tube screen. When pincushion distortion occurs in the vertical direction of the raster, the permanent magnet 7
The correction is performed by using one magnetic field. This permanent magnet 71
, Magnetic lines of force are generated from the N pole to the S pole of the permanent magnet 71, and the magnetic force acts so that the lower part of the central portion of the permanent magnet 71 acts most strongly. Therefore, the electron beam of the cathode ray tube
For example, if pincushion distortion occurs at the top and bottom of the screen by applying a magnetic force necessary for correcting raster distortion to the beams 59B, 59G, and 59R, the electron beams 59B, 59R.
The upper and lower pincushion distortions are corrected by applying the magnetic force of the permanent magnet 71 in the direction in which the G and 59R are pulled.

A deflection yoke device in which permanent magnets are arranged above and below is also disclosed, for example, in Japanese Patent Application Laid-Open No. 11-260288.

[0011]

As described above, if a relatively simple pincushion distortion is vertically symmetrical and the center portion is shrunk,
By simply disposing the permanent magnets 71 above and below as described above, pincushion distortion can be corrected relatively easily. However, depending on the assembling accuracy of the electron gun 60 and the mounting accuracy of the electron gun 60 in the neck 58, the tube axis of the cathode ray tube from the electron gun 60 to the phosphor screen 53 may be shifted from the mechanical center axis. In such a case, even if the horizontal deflection coil 65, the vertical deflection coil 66, the permanent magnet 71, and the like are arranged symmetrically, on the screen of the cathode ray tube,
Unbalanced distortions having different raster distortion directions as shown in FIGS. 8 and 9 occur. Further, as shown in FIG.
Distortions of different magnitudes may occur on the same side, and imbalance of higher-order raster distortions (seagull distortions) in which the generation positions differ at the top and bottom may also occur. In the case of a raster distortion of such a complicated shape that is asymmetric in the upper and lower sides and a distortion is also generated in an intermediate portion of the left and right halves of the same side, the permanent magnets 71 are simply arranged on the upper and lower sides. It is difficult to make corrections. In such a case, it is necessary to perform additional correction work such as separately attaching a permanent magnet for additional correction in accordance with the form of occurrence of the raster distortion. Since it is necessary to cope with the problem, not only is it necessary to prepare a number of permanent magnets 71, but also the correction work becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a relatively simple structure, and is capable of more easily and reliably improving raster distortion in a vertical direction. It is an object to provide a yoke device and a cathode ray tube.

[0013]

According to the present invention, there is provided a pair of saddle type horizontal deflection coils disposed inside a cylindrical core, and a pair of vertical deflection coils separately disposed via the horizontal deflection coil and a separator. In a deflection yoke device having a deflecting coil, permanent magnet holding portions provided at upper and lower portions of a large-diameter side opening of a separator, and a prismatic permanent magnet provided in the permanent magnet holding portion, a permanent magnet holding device is provided. A variable mechanism is provided in the section, and the permanent mechanism is configured to be movable and adjustable in the permanent magnet holding section by the variable mechanism.

A substantially rectangular face panel, a funnel-shaped funnel connected to the face panel, an electron gun disposed in the neck of the funnel to emit an electron beam, and the face facing the electron gun. A phosphor screen formed on the inner surface of the panel, a pair of saddle-type horizontal deflection coils disposed inside a cylindrical core disposed on the outer peripheral surface of the funnel, and separated from the horizontal deflection coil via a separator. A pair of arranged vertical deflection coils,
In a cathode ray tube having a permanent magnet holding portion provided on the upper and lower portions of the separator on the face panel side, and a deflection yoke device including a prismatic permanent magnet provided on the permanent magnet holding portion, a permanent magnet holding portion is provided. With a variable mechanism,
With this movable mechanism, the permanent magnet is configured to be movable and adjustable within the permanent magnet holding portion.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A deflection yoke device and a cathode ray tube according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a color cathode ray tube according to the present invention. The color cathode ray tube has a substantially rectangular face panel 11 and a skirt portion 1 of the face panel 11.
2 and a funnel-shaped funnel 13 joined to the face panel 11. Inside the face panel 11, a three-color phosphor layer and a black non-light-emitting layer formed on an inner surface of an effective portion of the face panel 11 are provided. Facing the phosphor screen 14
Shadow mask 1 in which many electron beam passage holes are formed
5 are arranged. The shadow mask 15 is fixed by welding to a mask frame 16, and the mask frame 16 is further fixed to the face panel 1 via an elastic support 17.
The first skirt portion 12 is engaged with a stud pin 18 formed on the inner surface. An in-line type electron gun 21 for emitting three electron beams 20B, 20G, and 20R is provided in the neck 19 of the funnel 13, and the three electron beams 20B, 20G, and 20R emitted from the electron gun 21 are supplied to the funnel 13. It is configured to be deflected by a magnetic field generated by a deflection yoke device 22 mounted on the outside of the device and horizontally and vertically scan the phosphor screen 14 to reproduce and display a color image. 23 is a purity convergence magnet, 24 is a magnetic shield, 25 is a lug piece for mounting, and 26 is a band for explosion proof.

As shown in FIG. 2, a deflection yoke device 22 used in this color cathode ray tube is made of synthetic resin such as polypropylene, and has a large diameter portion 27 located on the face panel 11 side of the cathode ray tube, and a cathode ray tube. A funnel-shaped separator 2 having a small diameter portion 28 located on the electron gun 21 side of the tube.
9 are formed. Inside the separator 29,
A pair of horizontal deflection coils 30 formed in a saddle shape are disposed vertically opposite to each other, and a pair of vertical deflection coils 31 similarly formed in a saddle shape are disposed outside the separator 29 so as to face left and right. I have. Further, a conical cylindrical core 32 made of ferrite or the like is mounted so as to cover the outer periphery of the middle part of the vertical deflection coil 31.
A terminal plate 33 is mounted in the vicinity of the small diameter portion 28 of FIG.

On the other hand, as shown in detail in FIG. 3, an outwardly projecting opening 34 is arranged on the face panel 11 side or the neck 19 side in the vertical direction of the periphery of the large diameter portion 27 of the separator 29. A box-shaped permanent magnet holding unit 35 is formed integrally with the separator 29 in a direction orthogonal to the axial direction of the horizontal deflection coil 30. This permanent magnet holder 35
For example, the upper permanent magnet holding portion 35 has an S pole on the left side and an N pole on the right side as viewed from the large-diameter portion 27 side of the separator 29.
Prismatic permanent magnet 3 magnetized and shaped so that poles are located
6 is mounted on the lower permanent magnet holding portion 35, and is formed into a prismatic permanent magnet 36 magnetized so that the N pole is on the left side in the opposite direction to the upper permanent magnet 36 and the S pole is on the right side. Are attached, and the lines of magnetic force generated by the permanent magnet 36 generate a magnetic force in a direction to attract the electron beams 20B, 20G, and 20R.

The separator 29 of the permanent magnet holding portion 35
A pair of elastic tongues 37 that generate elasticity in the opposite direction to the separator 29 are provided on the inner side surface. A pair of threaded through holes 38 is formed, and a bolt 39 is screwed into the through hole 38 from outside. The bolt 39 is made of a non-magnetic material such as a synthetic resin, and is designed not to affect the magnetic force of the permanent magnet 36. The movable mechanism 40 is constituted by the bolt 39 and the elastic tongue 37, and the permanent magnet 36 is moved by the movable mechanism 40 to the permanent magnet holder 3.
5, the movement can be adjusted. That is, the permanent magnet 36 is inserted from the opening 34 side of the permanent magnet holding portion 35 and positioned between the elastic tongue 37 and the inner wall of the permanent magnet holding portion 35. Thereafter, the bolts 39 are screwed into the through holes 38, and the tightening force of each of the bolts 39 is adjusted.
6 can be adjusted. For example, when the raster distortion as shown in FIG. 4 is corrected, the permanent magnet 36 may be moved in the permanent magnet holding portion 35 in parallel. Magnet 36
Can be translated in the tube axis direction, and the electron beam 20B, 20G, 20R receives the raster distortion indicated by the broken line in FIG. Beam 20B, 2
By attracting 0G and 20R, it is possible to correct to a correct raster indicated by a solid line in the figure.

When unbalanced raster distortion occurs on the same side as shown by the broken line in FIG. 5, a rotational force is applied in the direction of tightening the S pole side bolt 39, and N By applying a rotational force in a direction to loosen the pole-side bolt 39, the permanent magnet 36 can be rotated as shown in the drawing. As a result, by adjusting the permanent magnet closer to the side where the larger raster distortion is generated and by moving the permanent magnet away from the side where the smaller raster distortion is generated, these raster distortions are indicated by solid lines in the figure. Can be corrected as follows.

In such an adjustment, when it is desired to make the magnetic force of the permanent magnet 36 act strongly on the electron beams 20B, 20G, and 20R as a whole, a stronger magnetic force can be obtained by applying a rotational force in a direction in which both bolts 39 are tightened. In the case where it is desired to obtain a weak magnetic force as a whole, by applying a rotational force in a direction in which both bolts 39 are loosened, the permanent magnets 36 cause the electron beams 20B, 20G, 20R.
, The force exerted by the lines of magnetic force generated from the permanent magnets 36 can be reduced. In the raster distortion shown in FIGS. 8 to 10, the upper and lower sides are distorted in opposite directions. In this case, the upper and lower permanent magnets 36 are moved in opposite directions so that the upper and lower permanent magnets 36 move in opposite directions. The magnet 36 may be adjusted.

With this configuration, since the shape of the generated raster distortion is not invariable and uniform, the permanent magnet 36 is optimally adjusted by the bolt 39 in accordance with the form of the raster distortion. It can be moved to the correction position and the rotation can be adjusted if necessary. If it is desired to fix the adjusted position as it is, the bolt 39 or the permanent magnet 36 is fixed with an adhesive or the like after the adjustment. What is necessary is just to make it fix to the holding part 35. Of course, if there is no need for adjustment, the bolt 39 can be removed. The number of the bolts 39 and the shape of the elastic tongues 37 may be set according to the design or the state of the distortion. Further, since the bolt 39 can be adjusted from the outer circumferential direction, for example, even after the deflection yoke device 22 is mounted on the cathode ray tube, the movement of the permanent magnet 36 can be adjusted by adjusting the bolt 39, so that the adjustment of the permanent magnet 36 is easy. Can be done.

The present invention is not limited to the above-described embodiment. For example, the elastic tongue 37 is formed as a separate piece, and this is mounted together with the permanent magnet 36 in the permanent magnet holder 35. The permanent magnet 36 can be inserted into the permanent magnet holder 35 from the side by providing the opening 34 of the permanent magnet holder 35 horizontally. If it is sufficient to correct only one of the permanent magnets 36 and the bolt 39 in one of the vertical directions, the permanent magnet 36 and the bolt 39 can be omitted.
If it is not necessary to make the strength of the magnetic force in the upper and lower parts equal to each other, the length and size of the permanent magnet 36 can be changed. Further, the case where the vertical deflection coil 31 is constituted by the saddle type deflection coil has been described.
It can also be configured with a toroidal vertical deflection coil with a coil wound around it, and it can be applied to not only color cathode ray tubes but also black and white cathode ray tubes, and various other applications and modifications are possible. is there.

[0024]

As described above, according to the present invention, in spite of the relatively simple structure, not only the raster distortion can be easily and reliably corrected, but also the adjustment work is simple. It is possible to obtain a deflection yoke device that can be performed and a cathode ray tube having good screen characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a color cathode ray tube according to the present invention.

FIG. 2 is a perspective view showing a deflection yoke device according to the present invention.

FIG. 3 is a cross-sectional view showing a permanent magnet holding unit included in the deflection yoke device according to the present invention.

FIG. 4 shows a raster using a deflection yoke device according to the present invention.
FIG. 4 is an explanatory diagram showing a state of correction of distortion.

FIG. 5 is an explanatory diagram showing another raster distortion correction state.

FIG. 6 is a sectional view showing a conventional color cathode ray tube.

FIG. 7 is a perspective view showing a conventional deflection yoke device.

FIG. 8 is an explanatory diagram showing a conventional raster distortion.

FIG. 9 is an explanatory diagram showing another raster distortion.

FIG. 10 is an explanatory diagram showing another raster distortion.

[Explanation of symbols]

 11: Face panel 13: Funnel 14: Phosphor screen 19: Neck 20B, 20G, 20R: Electron beam 21: Electron gun 22: Deflection yoke device 27: Large diameter part 28: Small diameter part 29: Separator 30: Horizontal deflection coil 31: Vertical deflection coil 32: Core 35: Permanent magnet holder 36: Permanent magnet 37: Elastic tongue 39: Bolt 40: Adjusting mechanism

Claims (6)

[Claims] 1. A pair of saddle-type horizontal deflection coils disposed inside a cylindrical core, a pair of vertical deflection coils separately disposed via the horizontal deflection coil and a separator, and a diameter of the separator. In a deflection yoke device having a permanent magnet holding portion provided at the upper and lower portions of a large opening, and a prismatic permanent magnet provided at the permanent magnet holding portion, a variable mechanism is provided at the permanent magnet holding portion. A deflection yoke device wherein the permanent magnet is movably adjustable within the permanent magnet holding portion by the variable mechanism. 2. The deflection yoke according to claim 1, wherein the movable mechanism includes a plurality of bolts screwed to the permanent magnet holding portion, and adjusts the bolts to move the permanent magnet. apparatus. 3. The deflection yoke device according to claim 2, wherein the movable mechanism includes an elastic tongue in the permanent magnet holding portion so as to face the bolt. 4. A substantially rectangular face panel, a funnel-shaped funnel connected to the face panel, an electron gun arranged in a neck of the funnel to emit an electron beam, and the face facing the electron gun. In a cathode ray tube having a phosphor screen formed on an inner surface of a panel and a deflection yoke arranged on an outer peripheral surface of the funnel, the deflection yoke is a pair of saddle-type horizontal deflection arranged inside a cylindrical core. A coil, a pair of vertical deflection coils separated from the horizontal deflection coil and a separator, a permanent magnet holding portion provided on upper and lower portions of the separator on the face panel side, and a permanent magnet holding portion. A variable mechanism is provided in the permanent magnet holding section, and the permanent mechanism is provided by the variable mechanism. A cathode ray tube wherein a magnet is formed so as to be movable and adjustable within the permanent magnet holding portion. 5. The cathode ray tube according to claim 4, wherein the movable mechanism includes a plurality of bolts screwed to the permanent magnet holding portion, and adjusts the bolts to move the permanent magnet. . 6. The cathode ray tube according to claim 5, wherein the movable mechanism includes an elastic tongue in the permanent magnet holding portion so as to face the bolt.