JP3473156B2 - Color image display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image display device using an in-line type color picture tube, and more particularly to a convergence correction device therefor.

[0002]

2. Description of the Related Art A conventional color image display device will be described. A conventional color image display device using an in-line type color picture tube has R (red), G (green) and B emitted from in-line electron guns arranged in a line along a horizontal deflection axis.
A screen is formed by deflecting the three (blue) electron beams horizontally and vertically by a deflection yoke. Of course 3
The electron beam of the book must be concentrated on one point on the phosphor screen, but generally the distance from the deflection center is different in the center of the screen and other parts, so the concentration of the beam changes depending on the part of the screen and Deviation occurs.
A deflection yoke provided with self-convergence correction was proposed to improve this. This is realized by a deflection yoke in which the horizontal deflection magnetic field is a pincushion magnetic field and the vertical deflection magnetic field is a barrel magnetic field.

Further, in recent color image display devices, there is a great demand for higher resolution and higher density of the image, so that it becomes difficult to meet the demand only by the self-convergence correction, and the multipolar core is required. Deflection yokes have also been devised which are equipped with additional convergence correction devices, such as the sub-yoke according to US Pat. FIG. 7 shows an example thereof. In the figure, 15 is an in-line type color picture tube, 1
Reference numeral 6 is a neck portion of the in-line type color picture tube 15, and 9 is a deflection yoke attached to the in-line type color picture tube 15. Reference numeral 40 denotes a sub-yoke, which is provided with an 8-pole core 41 formed of, for example, a ferrite material, permalloy, or a silicon steel plate, and a correction current is passed through a coil 42 added to this core correction (especially VCR correction). Is to do.

The shape of the core of the sub-yoke is not limited to the octupole type, but may be a C-type or E-type core. Further, VCR correction means that since the vertical deflection coil forms a barrel magnetic field, the amount of vertical deflection of the G (green) electron beam with respect to the R (red) and B (blue) electron beams at the upper and lower edges of the screen. Is to correct the phenomenon that
Normally, a vertical deflection current is passed through the VCR correction coil 42 as shown in FIG. 8 to form a pin-shaped magnetic field 43 at the electron gun side end of the deflection yoke for correction.

By the way, the deflection yoke provided with such self-convergence correction requires the convergence axis deviation correction. The deviation of the convergence axis means that the deviation of the convergence occurs when vertical or horizontal unbalance is generated in the vertical or horizontal deflection magnetic field distribution with respect to the electron beam. When a convergence axis shift occurs, generally, the opening side of the deflection yoke is corrected by swinging the head vertically and horizontally along the horizontal deflection or vertical deflection axis. It is known that convergence changes and distortion also changes.

FIG. 9 is a diagram showing the left-right unbalance of the horizontal deflection magnetic field distribution and the resulting misalignment. The XH axis shift and the correction method therefor will be described with reference to FIG. As shown in FIG. 9A, in the figure, the XH axis shift is a shift that occurs when the horizontal deflection magnetic field 1 is left-right unbalanced with respect to the electron beam 2.
It means the deviation of the convergence of the left and right vertical lines of the red raster 3 and the blue raster 4 on the screen as shown in (b).
(It is assumed that the red raster 3 and the blue raster 4 before the left and right imbalances are matched.) Of course, when the left and right unbalance of the horizontal deflection magnetic field distribution opposite to that in FIG. The deviation is opposite to that in FIG. 9 (b). To correct this XH axis shift, the deflection yoke may be swung right and left along the horizontal deflection axis to remove the left-right unbalance of the horizontal deflection magnetic field distribution. For example, when a convergence axis deviation as shown in FIG. 9B occurs, it is obvious that the axis deviation can be removed by swinging the deflection yoke to the right.

The case where the deflection yoke 9 is swung right and left along the horizontal deflection axis will now be described. Figure 10
FIG. 6 is a diagram showing left and right unbalance of the vertical deflection magnetic field distribution due to left and right swing of the deflection yoke 9, and accompanying changes in convergence and raster distortion. When the opening of the deflection yoke 9 is swung to the left, the horizontal deflection magnetic field 1
And the vertical deflection magnetic field 5 is shown in FIG.
(A), left and right imbalance as shown in FIG. 10 (a) occurs, and at this time, the convergence change with respect to the swing neutral state is as shown in FIG. The spread and the change in strain with respect to the time of swing neutral (that is, the change in the green raster 6) are spread leftward as shown in FIG.

Of course, when the head is swung to the left, the changes are opposite to those shown in FIGS. 10 (b) and 10 (c). In such a change in convergence, in addition to the XH axis shift, there is a shift in the convergence of the horizontal lines of the upper and lower edges of the red raster 3 and blue raster 4 on the screen. YV that occurs in
It is misaligned. This is because when the deflection yoke is swung, the distribution of both the vertical deflection magnetic field and the horizontal deflection magnetic field is changed due to the structure of the deflection yoke. Further, since the magnetic field distribution is changed mainly on the deflection yoke opening side, the influence on the distortion is large. That is, if the deflection yoke is swung to the left or right to correct the XH axis shift, the YV axis shift and the distortion will change.

In order to solve this problem, there is a deflection yoke provided with a convergence device in which a magnetic piece is attached to the electron gun side end of the deflection yoke or the magnetic piece can be moved. FIG. 11 shows XH using such a magnetic piece.
FIG. 3 is a diagram showing a schematic configuration of an example of a correction device for correcting an axial deviation and a change in horizontal deflection magnetic field distribution when the correction device is used. FIG. 11A is a view of the deflection yoke 9 side of the in-line type color picture tube seen from the neck portion 16 side. In the figure, 7a and 7b are magnetic pieces, and 8 is a pair of magnetic pieces 7a arranged so as to sandwich the electron beam on the horizontal deflection axis.
And 7b are held, and the convergence correction device 11 is configured to move left and right along the horizontal deflection axis. The neck portion 16 is inserted into the device 11 to allow the convergence correction device 8 to move horizontally. It is an oval hole.

For example, as shown in FIG. 11B, when the pair of magnetic pieces 7a and 7b is displaced to the right when viewed from the neck side , it is as if the opening of the deflection yoke 9 is swung to the left. In addition, a horizontal imbalance of the horizontal deflection magnetic field 1 is created, and a change in convergence as shown in FIG. 9 (b) occurs as compared with the case where the pair of magnetic pieces 7a and 7b are symmetrical with respect to the tube axis. Let Naturally, the magnetic piece pair 7a,
The change in convergence when 7b is moved in the direction opposite to that in FIG. 11 (b) is opposite to that in FIG. 9 (b). However, when a pair of magnetic pieces is used, unlike the case where the deflection yoke is swung, there is almost no left-right imbalance in the vertical deflection magnetic field distribution, so there is almost no effect on the YV axis shift, and the electrons of the deflection yoke are not affected. There is almost no effect on distortion because it is applied at the gun side end.

Here, for example, VC is added to the above-mentioned 8-pole core 41.
Sub-yoke 4 for VCR correction around which R correction coil 42 is wound
It is quite natural to think of a combination of 0 and the convergence correction device 8 holding the pair of magnetic pieces 7a and 7b for correcting the XH axis deviation, but as a result of making a trial product and conducting an experiment,
The following problems were found to occur. The VCR correction coil 42 used in this prototype is wound around a ferrite 8-pole core 41 with a diameter of 90 mm and a thickness of 5 mm provided at the end of the deflection yoke 9 on the electron gun side as shown in FIG. I used the one. Further, two ferrite thin plates (30 × 5 mm, thickness 1 mm) were prepared and used for the magnetic piece pair 7a, 7b for correcting the XH axis shift provided in the convergence correction device 8. However, the magnetic piece pair 7 for XH axis deviation correction
In order to prevent the effect of the a and 7b from being shielded by the 8-pole core 41, a magnetic piece interval is set between the horizontal deflection coil of the deflection yoke 9 and the 8-pole core 41 at a position 3 mm away from the 8-pole core 41. (Magnetic piece movable range is fixed at 5 mm)
Placed as.

Under the above conditions, in order to correct the XH axis shift, for example, as in FIG.
When b is moved to the right when viewed from the neck side, a phenomenon occurs in which the YV axis shift is changed as shown in FIG. Of course, when the pair of magnetic pieces 7a and 7b is moved to the left, the change in the deviation of the convergence is opposite to that shown in FIG. This is because the VCR correction magnetic field distribution 43 is obtained by changing the positions of the XH axis shift correction magnetic piece pairs 7a and 7b.
This is because the left and right unbalances occur and the balance of the deflection amounts of the R (red) and B (blue) beams is lost. This phenomenon was measured only under the above conditions (that is, the VCR correction coil wound around the 8-pole core according to the above specifications).
It is considered that the same phenomenon occurs in VCR correction including the VCR correction coil wound around the E-type or C-type core.

14 and 15 show the results of measuring the amount of change in the XH-axis deviation and the YV-axis deviation under the above-mentioned conditions with the distance a between the XH-axis deviation correcting magnetic piece pairs 7a and 7b as a parameter. . It can be seen from FIGS. 14 and 15 that the XH axis deviation correction amount and the YV axis deviation change amount increase as the distance a between the pair of magnetic pieces decreases. The XH axis deviation correction amount is required to be about 0.8 mm or more, and for that purpose, the magnetic piece pair interval must be 45 mm or less. At this time, the change in the YV axis deviation is about 0.1 to 0.3 mm or more. The amount of change in the YV axis shift is not a value that can be ignored in practice, and results in disturbing the convergence quality of the color image display device.

[0014]

As described above, for example, the VCR correction sub-yoke 40 in which the VCR correction coil 42 is wound around the aforementioned 8-pole core 41 and the XH axis shift correction magnetic piece pair 7a, 7b are provided. Convergence correction device 8 held
In a conventional color image display device that simply combines the above, it is difficult to suppress the change amount of the YV axis deviation due to the correction of the XH axis deviation within an appropriate range, and it is difficult to perform the VCR correction and the convergence axis deviation correction. There was a problem that neither of these could be performed well. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a color image display device capable of performing both VCR correction and convergence axis shift correction with a simple structure.

[0015]

In the color image display device according to the first aspect of the present invention, three electron beams are generated along a horizontal deflection axis toward a phosphor screen coated with phosphors of three colors. A color picture tube having an in-line type electron gun, a deflection yoke having a horizontal deflection coil and a vertical deflection coil for deflecting an electron beam, which is mounted on the color picture tube between the fluorescent screen and the electron gun. It is placed on the electron gun side of the yoke,
In a color image display device having a sub-yoke composed of a multi-pole core around which a VCR correction coil is wound, a color image display device is arranged at predetermined intervals with an electron beam on the horizontal deflection axis.
From a first magnetic piece set consisting of one magnetic piece and four magnetic pieces arranged in a rectangular shape at predetermined intervals in the vertical deflection axis direction and the horizontal deflection axis direction so as to sandwich the electron beam diagonally. The second magnetic piece set is formed and a convergence correction device that is movable in the horizontal axis direction is provided near the sub-yoke.

In the color image display device according to the second aspect of the present invention, the convergence correction device is provided with a handle portion.

In the color image display device according to the third aspect of the present invention, a ferrite magnetic piece is used for the two magnetic pieces of the first magnetic piece set.

In the color image display device according to the fourth aspect of the present invention, the silicon steel sheet magnetic pieces are used as the four magnetic pieces of the second magnetic piece set.

In the color image display device according to the fifth aspect of the present invention, the two magnetic pieces of the first magnetic piece set are arranged so that the longitudinal direction thereof is along the horizontal deflection magnetic field direction.

In the color image display device according to the sixth aspect of the present invention, the four magnetic pieces of the second magnetic piece set are arranged so that their longitudinal directions are along the vertical deflection magnetic field direction.

[0021]

According to the first aspect of the present invention, the electron beam is diagonally aligned with the first magnetic piece set composed of two magnetic pieces arranged at a predetermined interval with the electron beam interposed on the horizontal deflection axis. A second magnetic flux composed of four magnetic pieces arranged in a rectangular shape at predetermined intervals in the vertical and horizontal deflection axis directions so as to be sandwiched between
Since the convergence correction device that holds the magnetic piece set of No. 1 and is movable in the horizontal axis direction is provided in the vicinity of the sub-yoke composed of a multi-pole core that performs VCR correction, the first magnetic piece set is used for convergence XH. When trying to correct the axis deviation, the second magnetic piece set cancels the occurrence of YV-axis convergence deviation induced by the change in the VCR correction magnetic field distribution due to the position change of the first magnetic piece set. Even in a color image display device including a sub-yoke formed of a multi-pole core around which a use coil is wound, good convergence axis deviation correction is possible.

According to the second aspect of the present invention, since the convergence correction device is provided with the handle portion, the adjustment work for correction can be facilitated.

According to the third aspect of the present invention, since the ferrite material having a good frequency characteristic is used for the magnetic pieces of the first magnetic piece set, a good convergence correction can be performed in response to a horizontal deflection magnetic field having a high frequency. It is possible.

According to the fourth aspect of the present invention, since the silicon steel plate material is used for the magnetic pieces of the second magnetic piece set which are not required to have high frequency characteristics, the convergence correction device can be realized at low cost.

In the fifth or sixth aspect of the present invention, since the longitudinal direction of the magnetic piece is arranged along the direction of the magnetic force line, a larger correction / cancellation effect can be obtained.

[0026]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In the figure, the same reference numerals as those in the conventional example indicate the same or corresponding ones as the conventional one. FIG. 1 is a view showing an embodiment of the present invention, and FIG. 1 (a) is a schematic configuration view of an in-line type color picture tube seen from the neck portion 16 side. In addition, FIG. 1B is a side view of the first embodiment shown in FIG. Before carrying out the embodiment 1 shown in FIG. 1, as a preliminary study for solving the above-mentioned conventional problems, as shown in FIG. 2A, the convergence for the purpose of the conventional XH axis misalignment correction is performed. It was examined what would happen if only the pair of magnetic pieces 10a and 10b for correcting the YV axis deviation were provided in the correction device 8.

Since the YV axis shift is caused by the left-right unbalance of the vertical deflection magnetic field distribution, in order to perform the YV axis shift correction with the magnetic pair as in the XH axis shift correction, FIG.
As shown in (a), the convergence correction device 8 is provided with a deflection correction yoke 8 capable of moving a pair of magnetic piece pairs 10a and 10b arranged so as to sandwich the electron gun on the vertical deflection axis to the left and right along the horizontal deflection axis. This is performed by arranging it at the end of 9 of the electron gun. For example, as shown in FIG. 2B, the magnetic piece pairs 10a, 1
When 0b is moved to the right when viewed from the tube surface, left and right imbalances occur in the vertical deflection magnetic field distribution 5, and the magnetic piece pair 10
A YV axis shift as shown in FIG. 2C occurs when a and 10b are located symmetrically with respect to the vertical deflection axis. Actually, using the magnetic piece pair 10a, 10b made of a silicon steel plate having a thickness of 30 × 3 mm and a thickness of 0.5 mm, the same conditions (specification of the 8-pole core 41, positional relationship, and As a result of measuring the YV axis shift correction effect at one insertion position), a change as shown in FIG. 2C was observed.
Although not shown, the XH axis shift is slightly changed.

By the way, the change of the YV axis deviation in the XH axis deviation correction and the moving direction of the pair of magnetic pieces 7a and 7b, and
Change of YV axis deviation and magnetic piece 10 in YV axis deviation correction
When the moving directions of a and 10b are compared, that is, when FIG. 13 and FIG. 2C are compared, the magnetic piece pairs 7a and 7b are compared.
When the moving directions of the pair of magnetic pieces 10a and 10b are the same, the change in the YV axis shift is in the same direction. Therefore, it is understood that the YV axis shift is in a direction to be further increased and it is inappropriate as a means for canceling. By the way, the movement of the magnetic piece pair 10a, 10b in the YV axis deviation correction shown in FIG. 2A is caused by the convergence correction device 8 which is a holding plate holding the magnetic piece pair 10a, 10b from a symmetrical position (center of the tube axis). When the magnetic piece is moved, the magnetic piece moves away from the center of symmetry, but when the magnetic piece holding plate (that is, the convergence correction device 8) is displaced from the symmetrical position, the magnetic piece approaches the center of symmetry. If so, it is considered that the change in the YV axis shift shows a movement opposite to the YV axis shift correction.

In order to realize such a deviation movement of the convergence axis deviation correction, as shown in FIG. 3, four magnetic pieces are symmetrically sandwiched between the vertical deflection axis and the horizontal deflection axis so that the electron beam is sandwiched diagonally. 20a to 20d may be arranged. Here, the YV axis deviation correction effect using the four magnetic pieces according to the configuration of FIG. 3 was measured under the same conditions as those for the XH axis deviation correction effect measurement (specification of the 8-pole core 41, positional relationship, and magnetic piece insertion position ). The four YV axis deviation correction magnetic pieces 20a to 20d are made of silicon steel plate (15 × 3 mm,
0.5mm thickness is used, the movable range of the magnetic piece is ± 2.5mm
The vertical and horizontal intervals of the magnetic pieces were set as parameters.

By the way, Y measured under the above conditions
When the magnetic piece is moved to the right when viewed from the tube surface as in FIG. 2B, the change in the V-axis shift is as shown in FIG. 4, and comparing FIG. 13 and FIG. Pair 7a,
It was found that when the four magnetic pieces 20a to 20d arranged in a rectangular shape sandwiching the electron beam 7b and the electron beam on the diagonal line move in the same direction, the change in the YV axis shift is opposite. Therefore, as a means for canceling the change in the YV axis shift, it has been found that it is effective to arrange four correction magnetic pieces in a rectangular shape with the electron beam sandwiched diagonally as shown in FIG. Was done. As is clear from FIG. 4, the XH axis deviation also changes, and the direction is in the direction of decreasing the XH axis deviation correction amount. However, as shown below, the XH axis deviation correction amount is set to a large value. It doesn't matter if you leave it.

FIG. 5 (a) shows the measurement conditions in which this phenomenon was measured using the vertical spacing a and the horizontal spacing b of the four magnetic pieces 20a to 20d for YV axis shift correction as parameters, and the measurement results are shown in FIG. 5 (b). ). From FIG. 5 (b), the spacing a of the magnetic pieces,
It can be seen that the smaller the value of b, the more the YV axis deviation correction amount tends to increase. As is clear from FIGS. 14 and 15, the YV axis deviation cancellation amount in the required XH axis deviation correction amount is about 0.1 mm or more, and all of the conditions under the above measured conditions satisfy this. On the other hand, it can be seen from FIG. 5 that the change in XH axis deviation that occurs at that time is about 0.1 mm or less. This does not cause a problem if the XH axis shift correction amount is set to be larger by the reduction amount. Therefore, the YV axis shift canceling method as shown in FIG. 3 is effective.

From the above, in the deflection yoke having a sub-yoke composed of a multi-pole core for VCR correction at the rear portion, the YV axis shift caused by the XH axis shift correction using the magnetic piece pairs 7a and 7b is corrected. The change is that four magnetic pieces 20a to 20d are arranged symmetrically with respect to the vertical deflection axis and the horizontal deflection axis so as to sandwich the electron gun diagonally, and the size or tube size of the magnetic pieces 20a to 20d. It was confirmed that the change in the YV axis shift can be effectively canceled by appropriately selecting the distance from the axis.

An embodiment of the present invention will be described here with reference to FIG. FIG. 1A is a view of the convergence correction device and the deflection yoke as viewed from the rear of the color picture tube. In the figure, 7a and 7b are magnetic piece pairs for XH axis deviation correction arranged so as to sandwich the electron beam on the horizontal deflection axis, and 20a to 20d are vertical deflection axis direction and horizontal so as to sandwich the electron beam on the diagonal line. Four magnetic pieces 30 for canceling the change in the YV axis deviation, which are arranged in a rectangular shape at predetermined intervals in the deflection axis direction, are magnetic pieces 7a, 7b and 20a to 20.
Reference numeral 9 denotes a deflection yoke which holds d and is movable in the horizontal deflection axis direction by an elliptic hole 11 into which the neck portion 16 of the color picture tube is inserted. Further, FIG. 1B is a diagram showing a state in which the deflection yoke 9, the convergence correction device 30, and the sub-yoke 40 formed of a multi-pole core for performing VCR correction in the present embodiment are arranged in the tube axis direction.

In the convergence correction device 30 as shown in FIG. 1, the XH axis deviation correctable amount is set to 1.0 mm, and if the magnetic piece movable range is too small, it becomes difficult to make delicate adjustments, and if it is too large, it takes up space. ± 2.5 from that
mm. In order to satisfy such a condition, the above-mentioned FIG.
Judging from the measurement results shown in, the XH axis misalignment correction magnetic pieces 7a and 7b have ferrite plates with a size of 30 × 5 mm and a thickness of 1 mm at an interval of 42 mm, and four YV axis misalignment canceling pieces. The magnetic pieces 20a to 20d are made of silicon steel plate having a size of 15 × 3 mm and a thickness of 0.5 mm, and a space of 40 mm in length and 37 in width
They were arranged at mm intervals. Further, a method of fixing the magnetic pieces 7a, 7b and 20a to 20d to the convergence correction device 30 will not be specifically described, but it is assumed that they are firmly fixed.

The sub-yoke 40 consisting of an 8-pole core is shown in FIG.
As shown in (b), it is arranged on the electron gun side of the convergence correction device 30, and its positional relationship is the same as the above-mentioned measurement conditions. In addition, the convergence correction device 3
0 is not limited to the space between the sub-yoke 40 and the deflection yoke 9. Of course, no problem occurs even if the sub-yoke 40 is arranged at the electron gun side end of the sub-yoke 40, and the same effect can be obtained. Further, the size, position and moving range of the magnetic pieces 7a, 7b and 20a to 20d are not particularly limited, and XH
It may be appropriately determined according to the amount of axial deviation correction and the amount of cancellation of the YV axial deviation change. Basically, first, the sizes, positions, and moving ranges of the magnetic pieces 7a and 7b for XH axis shift correction are determined so that the XH axis shift correction amount desired by the designer is obtained, and thereafter, according to the YV axis shift change cancel amount. The sizes and positions of the YV axis shift change canceling magnetic pieces 20a to 20d may be determined.

Regarding the magnetic pieces 7a, 7b and 20a to 20d, the convergence correction device 3 holding them.
In order to suppress the increase in the dimension of 0 in the tube axis direction as much as possible, a plate-like member is used and arranged so that the thickness direction is parallel to the tube axis. Further, the magnetic pieces 7a and 7b for XH axis deviation correction
Has the purpose of inducing left-right imbalance of a horizontal deflection magnetic field with a high frequency, so using a ferrite material that is long in the direction along the horizontal deflection magnetic field and has good frequency characteristics will produce a higher effect. In addition, it can be applied to multi-scan type products with a high horizontal deflection frequency, which have been developed in recent years. Also, Y
Four magnetic pieces 20a to 20 for canceling V-axis deviation change
As for d, the purpose is to induce left-right unbalance of the vertical deflection magnetic field of low frequency, so use an inexpensive silicon steel plate material that is not so good in frequency characteristics but is long in the direction along the vertical deflection magnetic field. As a result, it is possible to cancel the YV axis shift change inexpensively and effectively.

By the way, the magnetic pieces 7a, 7b and 20a
Convergence correction device 30 holding ~ 20d,
As shown in FIG. 1A, the neck portion 16 of the color picture tube is inserted so that the neck portion 16 can be moved left and right along the horizontal deflection axis (a length about the moving range of the magnetic piece). The hole 11 is formed so that it can be moved in the horizontal deflection axis direction without being affected by the electron gun portion (that is, the neck portion 16). Further, the convergence correction device 30 is attached to the deflection yoke 9 so that it can move left and right in the horizontal axis direction without tilting or rotating around the tube axis. (A structure for that purpose is not shown here.) Further, as shown in FIG. 1A, if the convergence correction device 30 is provided with the handle parts 12a and 12b, the convergence correction device 30 is moved in the horizontal direction. It is possible to improve workability when correcting the axis deviation. The size, shape and position of the handles 12a and 12b,
The number and the like are not particularly limited and may be determined as necessary.

Here, when the XH axis shift correction is performed using the convergence correction device 30 having the configuration shown in FIG. 1, the XH axis shift correctable amount, the YV axis shift change amount (others, corner portion, shaft end portion, R → B <B movement amount relative to R> and R / B → G <G movement amount relative to the midpoint between R and B> Misconvergence variation amount) and distortion (up / down / left / right pin and trapezoidal distortion) ) The change was measured. The results are shown in Fig. 6. The XH axis deviation can be corrected up to 1.15 mm, and the YV axis deviation change is 0.05 mm or less (almost 0
mm). Further, it was confirmed that the strain was within 0.1% of change in the vertical and horizontal pins and trapezoidal strain. The strain amount shown in FIG. 6 (b) is measured according to the Japan Electronic Machinery Manufacturers Association (EIAJ) standard [ED-2101J]. This result is practically sufficiently satisfactory.

[0039]

According to the first aspect of the present invention, when it is attempted to correct the XH axis shift of the convergence by the first magnetic piece set, V due to the position change of the first magnetic piece set.
Since the second magnetic piece set cancels the occurrence of YV axis convergence misalignment induced by the CR correction magnetic field distribution change, a color image display provided with a sub-yoke composed of a multi-pole core around which a VCR correction coil is wound. Even in the apparatus, there is an effect that it is possible to perform good convergence axis deviation correction.

According to the second aspect of the present invention, since the handle is provided in the convergence correction device, there is an effect that the adjustment work for correction is facilitated.

According to the third aspect of the present invention, since the ferrite material having good frequency characteristics is used for the magnetic pieces of the first magnetic piece set, it is possible to perform good convergence correction corresponding to the horizontal deflection magnetic field of high frequency. It has the effect of

According to the fourth aspect of the present invention, since an inexpensive silicon steel plate material is used for the magnetic pieces of the second magnetic piece set which are not required to have high frequency characteristics, there is an effect that the cost of the apparatus can be reduced.

According to the fifth or sixth aspect of the present invention, since the longitudinal direction of the magnetic piece is arranged along the direction of the magnetic force line, a larger correction / cancellation effect can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration and a state of arrangement of a convergence correction device of a color image display device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration in the case where only a magnetic piece pair for YV axis deviation correction is provided in a conventional convergence correction device for XH axis deviation correction, and a state of convergence change due to a change in the position of the magnetic piece pair. FIG.

FIG. 3 is a diagram showing a case where four magnetic pieces are arranged in a convergence correction device so as to sandwich an electron beam on a diagonal line.

FIG. 4 is a diagram showing a change state of a YV axis shift when the convergence correction device shown in FIG. 3 is arranged in the vicinity of a sub-yoke that performs VCR correction.

FIG. 5 is a diagram showing measurement conditions and measurement results for specifically measuring the state of change shown in FIG.

FIG. 6 is a diagram showing measurement results of the amount of change in convergence and strain when Example 1 of the present invention is carried out.

FIG. 7 is a schematic view of a deflection yoke peripheral portion of a conventional color image display device.

FIG. 8 is a diagram showing a general concept of a VCR correction method.

FIG. 9 is a diagram for explaining an XH axis shift.

FIG. 10 is a diagram for explaining a YV axis shift.

FIG. 11 is a schematic configuration diagram of a conventional convergence correction device for performing XH axis shift correction.

FIG. 12 is a diagram showing a configuration of a sub-yoke composed of a wound multi-pole core of a VCR correction coil.

FIG. 13 is a diagram showing a state of convergence change when correction is performed using a conventional convergence correction device in which a pair of magnetic pieces for XH axis correction are arranged near a sub-yoke for VCR correction.

14 is a diagram showing the measurement conditions and the measurement results when the convergence change is specifically measured by the convergence correction device of FIG.

FIG. 15 is a graph of the measurement results shown in FIG.

[Explanation of symbols]

1 Horizontal deflection magnetic field 2 Electron beam
5 Vertical Deflection Magnetic Fields 7a, 7b XH Axis Misalignment Correcting Magnetic Piece (First Magnetic Piece Set) 20a to 20d YV Axis Misalignment Change Canceling Magnetic Piece (Second Magnetic Piece Set) 9 Deflection Yoke 30 Convergence Corrector 40 Sub-yoke 41 Multi-pole core 4
2 VCR correction coil

Claims (6)

(57) [Claims] 1. A color picture tube having an in-line type electron gun for generating three electron beams along a horizontal deflection axis toward a phosphor screen coated with phosphors of three colors, and the phosphor screen. A deflection yoke mounted on the color picture tube between the electron guns and having a horizontal deflection coil and a vertical deflection coil for deflecting the electron beam, and a VCR correction unit arranged on the electron gun side of the deflection yoke. In a color image display device including a sub-yoke formed of a multi-pole core around which an application coil is wound, the color image display device is composed of two magnetic pieces arranged at a predetermined interval with the electron beam sandwiched between them on a horizontal deflection axis. The first set of magnetic pieces and the electron beam are arranged in a rectangular shape at predetermined intervals in the vertical deflection axis direction and the horizontal deflection axis direction so as to sandwich the electron beam diagonally.
Holding a second set of magnetic pieces consisting of one piece of magnetic piece, and
A color image display device comprising a convergence correction device movable in the horizontal deflection axis direction in the vicinity of the sub-yoke. 2. The color image display device according to claim 1, wherein the convergence correction device has a handle portion. 3. A color image display device according to claim 1, wherein a ferrite material magnetic piece is used for the two magnetic pieces of the first magnetic piece set. 4. The color image display device according to claim 1, wherein a silicon steel plate magnetic piece is used for the four magnetic pieces of the second magnetic piece set. 5. The color image display device according to claim 1, wherein the two magnetic pieces of the first magnetic piece set have their longitudinal directions along the horizontal deflection magnetic field direction. . 6. The color image display device according to claim 1, wherein the four magnetic pieces of the second magnetic piece set are arranged such that their longitudinal directions are along the vertical deflection magnetic field direction. .