JPH07220657A - Deflection yoke and cathode-ray tube using this - Google Patents

Abstract

PURPOSE:To provide an inexpensive deflection yoke whose external shape is not large by correcting raster angle of an image caused by an angular error or the earth magnetism at assembling time in an in-line system color CRT display device. CONSTITUTION:A horizontal deflection coil 3 is fixed inside an insulating support frame 2, and a vertical deflection coil 4 is fixed outside, respectively, and a ferrite core 5 is installed outside the vertical deflection coil 4. In this deflection yoke 1, a correcting coil 6 is wound inside the ferrite core 5 so as to surround an electron beam passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke of a CRT display device used for televisions, computer displays and the like.

[0002]

2. Description of the Related Art In a CRT display device, an electron beam is generated by an electron gun provided inside a neck portion of a glass bulb, and this electron beam is provided outside a connecting portion between a funnel portion and the neck portion. To deflect in the horizontal and vertical directions. The deflected electron beam reaches a predetermined position on the fluorescent screen provided inside the panel portion of the glass bulb. The electron beam that reaches the fluorescent screen causes the fluorescent substance to emit light, whereby an image is displayed on the screen. The deflection yoke includes a horizontal deflection coil and a vertical deflection coil. These two deflection coils are fixed inside and outside the hollow insulating support frame, respectively. A deflection yoke is fixed to the outside of the neck portion of the glass bulb so that the neck portion of the glass bulb penetrates the hollow portion of the insulating support frame.

When a horizontal deflection coil is fixed inside the insulating support frame and a vertical deflection deflection coil is fixed outside the insulation support frame, the relative error between the positions of these two deflection coils with respect to the tube axis of the CRT display device ( Rotation error) may occur. Also, when the assembled deflection yoke is mounted on the outside of the neck portion of the glass bulb, a rotation error with respect to the tube axis of the deflection yoke may occur. Further, when the electron gun is enclosed inside the neck portion of the glass bulb, a rotation error with respect to the tube axis of the electron gun may occur. That is, generally, in the assembled CRT display device, the electron gun, the horizontal deflection coil, the vertical deflection coil and the like have a rotation error with respect to the tube axis.

When an image is actually displayed on the screen of the CRT display device, in addition to the influence of the rotation error at the time of assembly, the influence of the geomagnetism in the tube axis direction at the place where the CRT display device is installed causes The entire projected image rotates on the screen. As a CRT display device in which such image rotation (raster rotation) is corrected, for example, the one disclosed in Japanese Utility Model Laid-Open No. 60-24052 is known (well known, not shown). That is, in the conventional CRT display device,
A support frame projecting like an arm is provided at the screen-side end of the deflection yoke, and the correction coil wound around this support frame is fixed. Then, apply a direct current to this correction coil,
A magnetic field is generated in the tube axis direction of the CRT display device. By controlling the direct current flowing through the correction coil, the direction and strength of the magnetic field by the correction coil are adjusted, the effects of assembly error and geomagnetism are canceled, and the rotation of the image is corrected.

[0005]

However, in the conventional CRT display device in which the raster rotation of the image is corrected, an arm-shaped projecting support frame is further provided at the end of the deflection yoke having a large outer diameter on the screen side. Since the correction coil is fixed to this support frame, the outer shape of the entire deflection yoke including the correction coil becomes large. In particular, recent CRT display devices tend to increase the deflection angle in order to reduce the depth. Therefore, the funnel portion of the glass bulb becomes steeply inclined, and the outer diameter of the deflection yoke on the screen side also increases accordingly. Therefore, when the CRT display device having a large deflection angle is provided with the correction coil having the same configuration as the conventional one, there is a problem that the outer shape of the deflection yoke is inevitably further increased. On the other hand, in recent CRT display devices, it is required to make the housing small, so that the space (vacant space) around the CRT incorporated in the housing is reduced. Therefore, increasing the size of the entire deflection yoke is not preferable in designing the CRT display device. Further, in the system in which the correction coil is provided at the end of the deflection yoke on the screen side, the distance between the deflection coil and the electron beam increases as the deflection angle increases, and the correction efficiency decreases.
Therefore, there are problems that the number of turns of the correction coil must be increased and the direct current supplied to the correction coil must be increased.

The present invention has been made in order to solve the above problems, and has a high correction efficiency of raster rotation of an image, a small outer shape, and a large deflection angle C.
An object is to provide a deflection yoke suitable for an RT display device.

[0007]

To achieve the above object, the deflection yoke of the present invention comprises a first end portion located on the screen side of the cathode ray tube and the first end portion located on the neck portion side of the cathode ray tube. Hollow insulating support frame having a second end portion having an outer diameter smaller than the end portion, a horizontal deflection coil provided inside the insulating support frame, and a vertical deflection provided outside the insulating support frame. A coil, a ferrite core provided outside the vertical deflection coil, and a correction coil provided inside the ferrite core for generating a magnetic field in the tube axis direction of the cathode ray tube. ing. In the above structure, the correction coil is preferably provided between the vertical deflection coil and the ferrite core. Alternatively, in the above structure, the correction coil is preferably provided between the vertical deflection coil and the insulating support frame. Alternatively, in the above configuration, the correction coil is preferably provided between the horizontal deflection coil and the insulating support frame. Alternatively, in the above structure, the correction coil is preferably spirally wound inside the ferrite core. Alternatively, in the above configuration, it is preferable that the correction coil is annularly wound inside the ferrite core and near the first end portion or the second end portion of the insulating support frame.
Alternatively, in the above configuration, the correction coil is divided into two, and is wound in an annular shape inside the ferrite core and near the first end and the second end of the insulating support frame. preferable. Further, in the above configuration, the correction coil provided near the first end of the insulating support frame and the correction coil provided near the second end of the insulating support frame may have different directions of the generated magnetic fields. It is preferable to configure Further, in each of the above-mentioned configurations, it is preferable to include a quadrupole magnetic field generation unit that is provided near the second end of the insulating support frame and that generates a quadrupole magnetic field in a plane perpendicular to the cathode ray tube field axis. Further, in the above structure, it is preferable that the quadrupole magnetic field generating means is at least one set of coils provided symmetrically with respect to the tube axis of the cathode ray tube. Further, it is preferable to use the deflection yoke having each of the above-mentioned configurations in the cathode ray tube.

[0008]

In each of the above constructions, the correction coil is not provided because it is provided further inside the ferrite core having an outer diameter smaller than the screen side end of the cathode ray tube (CRT) of the deflection yoke. When compared with the deflection yoke, the outer shape is almost the same. Further, when compared with the conventional deflection yoke having the correction coil on the end portion on the screen side, a special shape for holding the correction coil, for example, an arm-shaped protruding support frame is unnecessary, and its outer shape is considerably reduced. . Further, since the correction coil is located at a position quite close to the tube axis of the cathode ray tube, the distance between the correction coil and the electron beam is not so large, and the effect of correcting the image raster rotation is high. Therefore, the current applied to the correction coil is reduced, and the number of turns of the correction coil is reduced. Further, by providing a correction coil between the vertical deflection coil and the ferrite core, between the vertical deflection coil and the insulating support frame, or between the horizontal deflection coil and the insulating support frame, the outer shape of the deflection yoke is corrected. It is possible to maintain the size substantially the same as that without. Further, by spirally winding the correction coil inside the ferrite core, the conventional ferrite core can be used as it is without any special processing. In addition, depending on the thickness and number of turns of the correction coil, it may not be necessary to provide the correction coil on the entire inner surface of the ferrite core, and the correction coil may be provided near the first end portion or the second end portion of the insulating support frame. Even if it is wound in an annular shape, it is possible to generate a correction magnetic field in the tube axis direction. In addition, the correction coil is divided into two, inside the ferrite core, in the vicinity of the first end of the insulating support frame and in the second end.
It is possible to generate a correction magnetic field in the tube axis direction in the same manner even if each coil is wound in the vicinity of the end of the tube. Further, it is applied to a correction coil (first correction coil) provided near the first end of the insulating support frame and a correction coil (second correction coil) provided near the second end. By changing the direction and magnitude of the direct current to be generated so that the directions of the generated magnetic fields are different from each other, the raster rotation of the image is corrected by the first correction coil and generated by the second correction coil. The magnetic field makes it possible to correct the disturbance of concentration of three beams on the screen, which is additionally called the convergence disturbance, which is additionally generated by the tube axis magnetic field generated by the first correction coil. Further, a quadrupole magnetic field generating means is provided in the vicinity of the second end of the insulating support frame, and a quadrupole magnetic field is generated in a plane perpendicular to the tube axis of the cathode ray tube. It is possible to correct the misconvergence which is generated and which is additionally generated by the magnetic field in the axial direction of the tube for correcting the raster rotation of the image and in which the horizontal line of the cross hatch opens up and down. Further, by constructing the quadrupole magnetic field generating means by at least one set of coils provided symmetrically with respect to the tube axis of the cathode ray tube, the structure is simple and the efficiency of magnetic field generation can be increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIG. 5 shows the general construction of a general CRT display device. In FIG. 5, the glass bulb 1
Reference numeral 1 includes a neck portion 12, a funnel portion 13 and a face panel portion 14. Inside the neck 12,
Three electron beams 18 arranged inline horizontally
An electron gun 15 for generating (shown by one in the figure) is provided. On the inner surface of the face panel portion 14, a fluorescent screen 16 in which red, blue, and green fluorescent materials are separately arranged is provided. A shadow mask 17 having a large number of beam passage openings is arranged near the fluorescent screen 16. The deflection yoke 1 is fixed to the outside of the portion connecting the funnel portion 13 to the neck portion 12.

(First Embodiment) The construction of a preferred first embodiment of the deflection yoke of the present invention is shown in FIG. 1, which is a partially cutaway side view. In FIG. 1, the insulating support frame 2 is a substantially trumpet-shaped hollow body in which the outer diameter of the screen side end portion 2a is larger than the outer diameter of the neck side end portion 2b, and is mainly made of resin or the like. A horizontal deflection coil 3 is fixed inside the insulating support frame 2, and a vertical deflection coil 4 is fixed outside. A ferrite core 5 is mounted outside the center of the vertical deflection coil 4. A correction coil 6 for correcting the raster rotation of the image is spirally and evenly wound around the entire surface of the inside of the ferrite core 5. For example, in the case of a 17-inch CRT display device, the wire diameter of the correction coil 6 is 0.2 to 0.3 mm,
The number of turns is 150 turns. Further, the DC current applied to the correction coil 6 has a voltage of 3 to 5 V and a current of 70 to 120 mA.
The range is appropriate. If an attempt is made to generate a magnetic field of the same strength with the conventional configuration, the wire diameter and the number of turns of the correction coil will be 170 turns, and the applied DC current will be about 15
Since 0 mA is required, it can be seen that the present invention exhibits excellent effects.

The deflection yoke 1 having the above structure is mounted on the CRT display device shown in FIG.
When an image is displayed on 6 and raster rotation of the image occurs, if a DC current is applied to the correction coil 6,
A magnetic field is generated in the tube axis direction of the CRT display device.
By adjusting the magnitude and direction of the direct current applied to the correction coil 6, the strength and direction of the generated magnetic field can be adjusted. Therefore, although the raster rotation of the image generated by the rotation error of each component at the time of assembling the individual CRT display device or the influence of the geomagnetism at the installation location is different depending on the individual CRT display device, the extent of the raster of the image is different. Even rotation is almost completely corrected.

In the first embodiment shown in FIG. 1, the correction coil 6 is uniformly spirally wound over the entire inner surface of the ferrite core 5, but the line thickness of the correction coil 6 and Depending on the number of turns, it may be wound on only a part inside the ferrite core 5, or may be partially wound in multiple layers. If these correction coils 6 are not evenly wound, the substantial inner diameter of the correction coil 6 becomes larger when the deflection coil 1 is mainly wound on the screen side end 2a side, and the tube axis generated by the correction coil 6 becomes larger. The correction magnetic field in the direction becomes more uniform.

(Second Embodiment) FIG. 2 shows a second embodiment of the deflection yoke of the present invention. Note that members given the same numbers as those in FIG. 1 are substantially the same, and the description thereof will be omitted. In FIG. 2, the correction coil 6 is divided into two, a first correction coil 6a and a second correction coil 6b. The first correction coil 6a is wound around the front end of the ferrite core 5, that is, near the screen-side end 2a of the insulating support frame 2. The second correction coil 6b is wound around the rear end of the ferrite core 5, that is, near the end 2b on the neck side of the insulating support frame 2.

When the correction coil 6 is divided into two in this way, one of the correction coils, for example, the first correction coil 6a provided on the front end side of the ferrite core 5 is used to correct the raster rotation of the image. It is possible to pass a current, and to apply a reverse direct current to the other correction coil, for example, the second correction coil 6b provided on the rear end side of the ferrite core 5. That is, the magnetic field generated by the second correction coil 6b corrects the disturbance of concentration of three beams on the screen, which is so-called convergence disturbance, which is additionally generated by the tube magnetic field generated by the first correction coil 6a. To do.

On the other hand, when simply correcting the raster rotation of the image, the first correction coil 6a or the second correction coil 6b is used.
You may comprise so that only any one may be provided. Alternatively, the first correction coil 6a and the second correction coil 6b may be connected in series, and the magnetic field generated by both the coils 6a and 6b may be used to correct the raster rotation of the image. If the number of correction coils is one, the first
In the same manner as in the first embodiment, the first inner diameter of the ferrite core 5 on the front end side can be increased because the substantial inner diameter of the correction coil can be increased.
The correction magnetic field becomes more uniform when the correction coil 6a is provided.

Further, in FIG. 2, a recess is provided inside the ferrite core 5 in order to accommodate the correction coils 6a and 6b. The degree of this recess depends on the thickness of the correction coils 6a and 6b and the number of windings. It should be designed accordingly, and in some cases the coil can be accommodated without providing the recess.

In the first and second embodiments, the correction coils 6, 6a and 6b are provided inside the ferrite core 5 and outside the vertical deflection coil 4.
The present invention is not particularly limited to this, and even if it is provided between the insulating support frame 2 and the vertical deflection coil 4 or between the insulating support frame 2 and the horizontal deflection coil 3, the gist thereof is changed. Not a thing. However, in consideration of the manufacturing process of the deflection yoke, by providing the correction coil 6 between the ferrite core 5 and the vertical deflection coil 4 as shown in the above embodiments, the conventional manufacturing process of the deflection yoke is performed. Can be applied without much change. As a result, the manufacturing efficiency is high, and the characteristics of the deflection yoke can be sufficiently maintained.

(Third Embodiment) As a third embodiment of the deflection yoke of the present invention, FIG. 3 shows the deflection yoke of the first or second embodiment to which a quadrupole magnetic field generating function is added. .
FIG. 3 is a view of the deflection yoke of the third embodiment mounted on, for example, the CRT display device shown in FIG. 5 and viewed from the neck portion 12 side of the CRT display device. In FIG. 3, further two magnetic field generating coils 21 and 22 are arranged in the horizontal direction in the drawing behind the end portion 2b on the neck side of the insulating support frame 2 of the deflection yoke 1 of the first or second embodiment. There is. That is, the magnetic field generating coils 21 and 22 are
The electron guns 15 arranged in the neck portion 12 of the display device are arranged in the same direction as the electron beam arrangement direction. The magnetic field generating coils 21 and 22 are configured by winding coils around the “I” -shaped core so as to generate opposite magnetic fields, and as a result, a quadrupole magnetic field shown by a broken line 23 in the drawing is generated. Occur. This quadrupole magnetic field is the first
And a horizontal line of the crosshatch generated by the correction coils 6, 6a and 6b provided in the deflection yoke 1 in the second embodiment and additionally generated by the tube axial magnetic field for correcting the raster rotation of the image. Corrects misconvergence that opens up and down.

(Fourth Embodiment) As a means for generating a quadrupole magnetic field for correcting such lateral line misconvergence, the magnetic field generating coils 25 and 26 are provided as in the fourth embodiment shown in FIG. You may arrange | position in the direction perpendicular | vertical with respect to the arrangement direction of an electron beam. Alternatively, the magnetic field generating coils may be arranged at four positions (four positions above and below and to the left and right with respect to the electron gun) in the same direction as the electron beam arrangement direction and in the direction perpendicular thereto. Further, the shape of each core of the magnetic field generating coils 21, 22, 24, 25 is not limited to the “I” shape, and the same effect can be obtained even if the cores are “U”, “E”, and “O” shapes.

[0020]

As described above, according to the present invention, since the correction coil for generating the magnetic field for correcting the raster rotation of the image is provided inside the ferrite core, a special coil for fixing the correction coil is provided. No such means, for example, a support frame protruding like an arm is unnecessary, and the outer shape of the deflection yoke is not increased. Further, since the distance between the correction coil and the electron beam is short, the efficiency of the correction coil is increased, and the number of turns of the coil and the direct current flowing through the coil can be reduced. Therefore, the cost is reduced, and when assembling as a CRT display device, no special consideration is required in the design of the housing. Also, since the correction coil is provided between the vertical deflection coil and the ferrite core, between the vertical deflection coil and the insulating support frame, or between the horizontal deflection coil and the insulating support frame, the outer shape of the deflection yoke is adjusted to the correction coil. Can be maintained at substantially the same size as those without. Further, by spirally winding the correction coil inside the ferrite core, the conventional ferrite core can be used as it is without any special processing.
In addition, depending on the thickness and number of turns of the correction coil, it may not be necessary to provide the correction coil on the entire inner surface of the ferrite core, and the correction coil may be provided near the first end portion or the second end portion of the insulating support frame. Even if it is wound in an annular shape, a correction magnetic field in the tube axis direction can be similarly generated. Also, even if the correction coil is divided into two and wound in an annular shape inside the ferrite core and near the first end and the second end of the insulating support frame, the correction in the tube axis direction is similarly performed. A magnetic field can be generated.
Further, it is applied to a correction coil (first correction coil) provided near the first end of the insulating support frame and a correction coil (second correction coil) provided near the second end. By changing the direction and magnitude of the direct current to be generated so that the directions of the generated magnetic fields are different from each other, the raster rotation of the image is corrected by the first correction coil and generated by the second correction coil. By the magnetic field, it is possible to correct the disturbance of the concentration of the three beams on the screen, so-called convergence disturbance, which is additionally generated by the tube axis magnetic field generated by the first correction coil. Further, a quadrupole magnetic field generating means is provided in the vicinity of the second end of the insulating support frame, and a quadrupole magnetic field is generated in a plane perpendicular to the tube axis of the cathode ray tube. It is possible to correct the misconvergence which is generated and which is additionally generated by the magnetic field in the tube axis direction for correcting the raster rotation of the image and in which the horizontal line of the crosshatch opens up and down. Further, by constructing the quadrupole magnetic field generating means by at least one set of coils provided symmetrically with respect to the tube axis of the cathode ray tube, the structure is simple and the efficiency of magnetic field generation can be increased.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a configuration of a first embodiment of a deflection yoke according to the present invention.

FIG. 2 is a partially cutaway side view showing a configuration of a second embodiment of a deflection yoke according to the present invention.

FIG. 3 is a rear view showing the configuration of a third embodiment of the deflection yoke according to the present invention.

FIG. 4 is a rear view showing the configuration of a fourth embodiment of the deflection yoke according to the present invention.

FIG. 5 is a partially cutaway plan view showing the configuration of a general CRT display device.

[Explanation of symbols]

 1: Deflection yoke 2: Insulation support frame 3: Horizontal deflection coil 4: Vertical deflection coil 5: Ferrite core 6: Correction coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanobu Honda, No. 1 Sachimachi, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd. (72) Asato Aoki, No. 1 Sachimachi, Takatsuki City, Osaka Matsushita Electronic Industry Co., Ltd.

Claims (11)

[Claims] 1. A first device located on the screen side of a cathode ray tube.
A hollow insulating support frame having an end portion and a second end portion having a smaller outer diameter than the first end portion located on the neck portion side of the cathode ray tube, and provided inside the insulating support frame. A horizontal deflection coil, a vertical deflection coil provided outside the insulating support frame, a ferrite core provided outside the vertical deflection coil, and a tube axis direction of the cathode ray tube provided inside the ferrite core. A deflection yoke having a correction coil for generating a magnetic field in the. 2. The deflection yoke according to claim 1, wherein the correction coil is provided between the vertical deflection coil and the ferrite core. 3. The deflection yoke according to claim 1, wherein the correction coil is provided between the vertical deflection coil and the insulating support frame. 4. The deflection yoke according to claim 1, wherein the correction coil is provided between the horizontal deflection coil and the insulating support frame. 5. The deflection yoke according to claim 1, wherein the correction coil is spirally wound inside the ferrite core. 6. The correction coil is inside the ferrite core,
3. The deflection yoke according to claim 1, further comprising an insulating support frame wound around the first end portion or the second end portion in an annular shape. 7. The correction coil is divided into two and is wound in an annular shape inside the ferrite core and near the first end and the second end of the insulating support frame. Alternatively, the deflection yoke according to item 2. 8. A correction coil provided near the first end of the insulating support frame and a correction coil provided near the second end of the insulating support frame have different directions of generated magnetic fields from each other. Deflection yoke according to 7. 9. A quadrupole magnetic field generating means for generating a quadrupole magnetic field in a plane perpendicular to the tube axis of the cathode ray tube, the quadrupole magnetic field generating means being provided in the vicinity of the second end of the insulating support frame. The deflection yoke according to any one of the above. 10. The deflection yoke according to claim 9, wherein the quadrupole magnetic field generating means is at least one set of coils provided symmetrically with respect to the tube axis of the cathode ray tube. 11. A cathode ray tube using the deflection yoke according to any one of claims 1 to 10.