JP2001023540A - Color image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct misconvergence caused by a rotation displacement of an arrangement axis of an electron beam. SOLUTION: A B-BOW correction device 30 is arranged close to an end on a CRT neck part side end on a deflection yoke 8. A flat plate member 32 of the B-BOW correction device 30 has a main surface 32S in a rectangle shape, and a through hole 33 is formed near the center of the rectangle. The CRT neck part is inserted into and fitted in the through hole 33 to install the B-BOW correction device. Two magnetic pieces 31 are arranged symmetrically about the through hole 33 (that is a tube axis Z of CRT) on the main surface 32S of the flat plate member 32. Rotating the flat plate member 32 about the tube axis Z (or the neck part) while the flat plate is orthogonal to the tube axis Z controls a distribution of a horizontally deflected magnetic field close to the neck part side end on the deflection yoke 8 to correct deflection states of various electron beams caused by a rotation displacement.

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, and more particularly to a color image display device for correcting and adjusting convergence of a color CRT (Cathode Ray Tube) having an in-line type electron gun (in-line type color CRT). About technology.

[0002]

2. Description of the Related Art In an in-line type CRT or a color image display having the same, each electron beam emitted from each of three electron guns arranged in a row is deflected horizontally and vertically by a deflection yoke. . The phosphor on the phosphor screen is scanned by the deflection of the electron beam to form a display image or image.

[0003] At this time, three electron beams are irradiated on the phosphor screen by one.
Although it is necessary to concentrate (convergence) at a point, the degree of concentration of the electron beam depends on a part in the screen, because the distance from the center of deflection is different between the central part of the screen and other parts. Such a difference in the degree of concentration of the electron beam can be removed by self-convergence correction, and such correction is realized by a deflection yoke using a horizontal deflection magnetic field as a pincushion magnetic field and a vertical deflection magnetic field as a barrel magnetic field.

However, at present, it is inevitable that misconvergence occurs due to variations between individual deflection yokes or mismatches between deflection yokes due to variations between individual CRTs. It is common to provide a circuit. As the misconvergence correction circuit, (a) misconvergence correction by misalignment between the deflection yoke and the electron beam (correction of misconvergence of Yv-axis shift, Yh-axis shift, and Xv-axis shift); Misconvergence correction (B-BOW, Yv misconvergence correction) due to rotational deviation from the electron beam (around the CRT tube axis) is widely used. A misconvergence pattern that cannot be corrected even by a misconvergence correction circuit mounted on the deflection yoke is generally corrected using a ferrite sheet. The correction by the ferrite sheet is basically applied to the misconvergence at the corner of the screen. Usually, the above-described misconvergence correction circuit and ferrite sheet are fixed after being optimized in the misconvergence correction operation.

[0005] Here, misconvergence due to rotational displacement between the deflection yoke and the electron beam will be described.

First, the B-BOW misconvergence will be described. B-BOW misconvergence refers to, for example, a color CRT having an in-line type electron gun that emits a green (G) electron beam and red (R) and blue (B) electron beams sandwiching the electron beam. As shown in FIG. 12 and FIG. 13, a horizontal line convergence shift at the left and right ends of the red raster 1R and the blue raster 1B (shown by broken lines) on the screen is referred to. ). For example, the misconvergence pattern shown in FIG. 12 includes a horizontal deflection axis 3X of a pincushion-type horizontal deflection magnetic field 3 and three electron beams R, G, and B for red, green, and blue, as shown in FIG. This occurs when the arrangement direction of B or the arrangement axis 5 is out of rotation. Note that FIGS. 14 and drawings corresponding to FIG. 14 to be described later show components such as a magnetic field distribution and an electron beam when viewed from a display screen or a tube surface side. In this case, as shown in FIG. 14, each of the electron beams R, G, and B is deflected below the red electron beam R by the horizontal deflection magnetic field 3, which is a pincushion magnetic field, on the left and right sides of the screen. (Each deflection direction is indicated by the direction of a thick arrow, but the directions are slightly emphasized), so that the misconvergence pattern shown in FIG. 12 occurs. As shown in FIG. 15, when the horizontal deflection axis 3X and the array axis 5 of the electron beams are rotationally displaced in a direction opposite to that in FIG.
The misconvergence pattern shown in FIG. 13 occurs.

Next, the Yv misconvergence due to the rotational displacement will be described. The Yv misconvergence is different from the above-described B-BOW, and is a misconvergence in which the entire red raster 1R shifts upward and the entire blue raster 1B shifts downward as shown in FIG. 16, for example. Y in FIG.
As shown in FIG. 17, the v-misconvergence indicates that when the rotational deviation occurs between the vertical deflection axis 6Y of the barrel-shaped vertical deflection magnetic field 6 and the array axis 5 of the electron beams, each of the electron beams R, G, B This is caused by the difference in the amount of deflection (indicated by the length of the thick arrow in FIG. 17) due to the difference in the magnitude of the magnetic flux of the barrel magnetic field that is received. In the case where a rotational displacement occurs in the direction opposite to the case of FIG. 17, the positions of the rasters 1R and 1B in FIG. 16 are reversed.

FIG. 1 shows an example of a method for correcting the B-BOW misconvergence and the Yv misconvergence described above.
The method using the four-pole magnet 19 shown in the side view of the color image display device 50 of FIG. As shown in FIG. 18, the color image display device 50 includes an in-line type electron gun 2.
0, the color CRT 10, the deflection yoke 8, and the CR
CP-ASSY9 arranged at neck 10N of T10
And a quadrupole magnet 19 disposed at the end 8N of the deflection yoke 8 on the neck 10N side. Note that C
The P-ASSY 9 is a component in which various correction magnets such as two poles, four poles, and six poles are combined. In such a configuration, the arrangement axis 5 of the electron beam is rotated about the tube axis Z or the green electron beam G by using the quadrupole magnet 19 and the quadrupole magnet for adjusting the static convergence in the CP-ASSY 9. By the B-BOW
Alternatively, the Yv misconvergence is corrected.

[0009]

In the above-described correction method, the four-pole magnet for adjusting the static convergence included in the CP-ASSY 9 acts more than the case where only the static convergence is adjusted. , B enters the deflection yoke 8 to rotate the arrangement axis 5 of the electron beams to correct the rotational deviation, and then corrects the static convergence by the quadrupole magnet 19.

However, when the static convergence adjusting quadrupole magnet included in the CP-ASSY 9 is adjusted to such a large value, the positional relationship between the electron beam and the electron lens (not shown) of the electron gun 20 is broken. (The electron beam deviates from the lens system), which causes a problem of inducing a decrease in focus. For this reason, in practice, the amount of correction of B-BOW or Yv misconvergence must be limited in order to suppress a decrease in focus.
It is difficult to remove BOW or Yv misconvergence.

Further, in the above-described correction method, the arrangement axis 5 of the electron beam is rotated before the light beam enters the deflection yoke 8, so that B
There is a problem that correction of BOW and Yv misconvergence can only be performed simultaneously. That is,
The above-described correction method uses the B-BOW misconvergence and Y
There is a problem that the method cannot be applied to a case where only one of the v-miss convergence and the correction amount and the direction of the B-BOW mis-convergence are different from those of the Yv mis-convergence.

In particular, in order to further increase the size and definition of a CRT, it is strongly desired to surely correct misconvergence without lowering the focus of an electron beam.

The present invention has been made in view of the above points, and provides a color image display device capable of correcting B-BOW misconvergence and / or Yv misconvergence without causing a decrease in focus of an electron beam. This is the first object.

It is a second object of the present invention to provide a color image display device capable of independently correcting both B-BOW misconvergence and Yv misconvergence.

Further, a third object of the present invention is to provide a color image display device having a higher screen quality than the conventional color image display device by realizing the first or second object. .

[0016]

According to a first aspect of the present invention, there is provided a color image display apparatus including: a color CRT having an in-line type electron gun at a neck portion thereof; and a deflection C mounted on the color CRT. The yoke and the yoke are arranged symmetrically with respect to the tube axis on a plane perpendicular to the tube axis of the color CRT and close to the end of the deflection yoke on the neck side side, while maintaining the symmetric relationship. At least one pair of magnetic pieces arranged so as to be rotatable about the tube axis in the plane is provided.

(2) The color image display device according to the second aspect of the invention is the color image display device according to the first aspect, wherein the color CRT is inserted into the neck portion of the color CRT and has a main surface thereof. Is characterized by further comprising a flat plate member forming the flat surface, wherein the pair of magnetic pieces is fixed to the flat plate member.

(3) A color image display device according to a third aspect of the present invention is the color image display device according to the first or second aspect, further comprising two pairs of the magnetic pieces, and The magnetic pieces are arranged so that the rotation can be performed independently of each other.

[0019]

<First Embodiment> FIG. 1 is a schematic side view of a color image display device 51 according to a first embodiment. As shown in FIG.
(A) Color C having an in-line type electron gun 20
An RT (in-line type color CRT) 10, (b) a deflection yoke 8 mounted on the color CRT 10, (c) a CP-ASSY 9 disposed on (a portion of the neck 10N of the color CRT 10 where the electron gun 20 is disposed). (D) B-characteristic of the color image display device 51, which is disposed close to the end 8N of the deflection yoke 8 on the neck 10N side.
BOW misconvergence correction device (hereinafter referred to as “B-BO
W correction device) 30). In addition, CRT
Since a well-known in-line type color CRT and an electron gun can be applied as the electron gun 10 and the electron gun 20, respectively, FIG. 1 illustrates various components such as a reinforcing band of the CRT 10 and a detailed structure of the electron gun 20. Is omitted. In addition, since a well-known self-convergence correction type deflection yoke can be applied as the deflection yoke 8, FIG.
In FIG. 1, the deflection yoke 8 is schematically illustrated without illustration of components such as coils. The same applies to the following drawings equivalent to FIG. Also, CP-ASSY9
Are magnets (2 pole, 4 pole, 6 pole) for various corrections such as static convergence and color purification (purity).
Extreme. For example, a two-pole magnet is used as a color-purifying magnet).

Here, in addition to FIG. 1, the B-BOW will be described with reference to FIG. 2 which is a drawing (rear view) when the color image display device 51 is viewed from the neck portion 10N side of the CRT 10.
The correction device 30 will be described. 2, illustration of the CRT 10 is omitted.

As shown in FIGS. 1 and 2, the B-BOW correction device 30 includes (d-1) a flat plate member 32 having a through hole 33 formed in its thickness direction, and (d-2) a flat plate member. 32
And two (one pair) magnetic pieces (made of a soft magnetic material) 31 symmetrically arranged on the main surface 32S of the through hole 33 with respect to (the center axis of) the through hole 33; Handle 35 provided in the section (however, in order to avoid complication of the drawing, FIG.
(Illustration thereof is omitted). And B
As shown in FIG. 1, the −BOW correction device 30 is disposed near the neck-side end 8 </ b> N of the deflection yoke 8.
Hereinafter, the configuration of the B-BOW correction device 30 will be described in detail.

First, the flat plate member 32 has, for example, a rectangular main surface 32S (here, the main surface on the side of the neck portion 10N), and a through hole 33 is formed near the center of the rectangle. In particular, the through hole 33 is formed in the neck 10 of the CRT 10.
N and has a shape and dimensions that allow it to rotate around the neck 10N (or the tube axis Z of the CRT 10). Then, the main surface 32S is rotatable in a state perpendicular to the neck portion 10 or the tube axis Z (for this reason, the arrangement of the flat plate member 32 shown in FIG. 2 is merely an example), and The shapes and dimensions of the flat plate member 32 and the through hole 33 are defined so that the center of rotation does not deviate from the tube axis Z.

Then, 2 is placed on the main surface 32S of the flat plate member 32.
The magnetic pieces 31 are arranged symmetrically with respect to the tube axis Z with the through hole 33 (accordingly, the tube axis Z) interposed therebetween. At this time, the magnetic piece 31 is firmly fixed to the flat plate member 32, for example, by being held by a claw (not shown) provided on the flat plate member 32 or by an adhesive or the like. in this way,
Since the two magnetic pieces 31 are arranged on the main surface 32S of the flat plate member 32, the two magnetic pieces 31 are kept in the tube axis Z while maintaining the positional relationship of the two pieces 31 with respect to the tube axis Z. The rotation about the tube axis Z in a plane perpendicular to the plane (here, the main surface 32S corresponds to this) can be easily performed.

The size, shape, arrangement position (for example, distance from the tube axis Z), rotatable range, and the like of the magnetic piece 31 are appropriately set in accordance with a correction amount in a B-BOW correction method described later.

In particular, the pair of magnetic pieces 31 is a plane perpendicular to the tube axis Z and has the neck-side end 8 N of the deflection yoke 8.
Are arranged symmetrically with respect to the pipe axis Z on a plane close to the pipe, and as long as the rotation about the pipe axis Z is possible in the plane while maintaining the symmetric relationship, B-BO
Various forms can be applied as the W correction device. For example, the magnetic piece 31 may be arranged on the main surface opposite to the main surface 32, that is, on the main surface of the flat plate member 32 on the deflection yoke 8 side. Of course, the main surface 32S of the flat plate member 32 may have a shape other than a rectangle. Further, the through hole 33 whose opening shape is illustrated as a circle in FIG. 2 may be, for example, a square shape or a polygonal shape, or may be formed at a position shifted from the vicinity of the center of the main surface 32S. Also, as shown in FIG. 3 corresponding to FIG. 2, the end 8N of the deflection yoke 8 on the neck side is extended more than in the case of FIG.
2 may be inserted into the extended end 8T to enable the above-described rotation.

The handle 35 is made of, for example, the flat plate member 3.
A rectangular flat plate member 3
2 are provided at both ends in the longitudinal direction. The handle 35 itself is not an essential component of the B-BOW correction device, but the handle 35 can improve the workability of a B-BOW correction operation described later. The workability is further improved by appropriately setting the size, shape, mounting position, number, and the like of the handles 35 according to the size of the CRT 10 and the work environment at the time of B-BOW correction described later. be able to.

Next, the B-BOW correction device 30
The principle or method of the BOW misconvergence correction will be described with reference to FIGS. 4 and 5
Is the horizontal deflection magnetic field 3N in the vicinity of the end 8N of the deflection yoke 8 near the neck of the deflection yoke 8 and the red (R), green (G), and blue (B) electrons generated by the magnetic field 3N. FIG. 14 is a schematic diagram for explaining the relationship between the deflection directions of the beams R, G, and B (indicated by the direction of the bold arrows), as in the case of FIG. FIG. Here, as described above, the horizontal deflection magnetic field 3N in FIGS. 4 and 5 shows the magnetic field distribution near the neck side end 8N of the deflection yoke 8, whereas the horizontal deflection magnetic field 3N in FIG. The horizontal deflection magnetic field 3 indicates the same magnetic field on an arbitrary plane perpendicular to the tube axis Z in the arrangement range of the deflection yoke 8 (of the conventional color image device 50). In particular, the horizontal deflection magnetic field in the color image display device 51 is
In the vicinity of the neck-side end 8N, for example, the state shown in FIG. 4 or FIG. 5 is shown. On the other hand, the distribution continues as the horizontal deflection magnetic field 3 in FIG. Change. For convenience of explanation, in FIGS. 4 and 5, the direction of the magnetic field on the left side toward the paper surface (accordingly, toward the tube surface 10S) deflects the electron beams R, G, and B to the left toward the tube surface 10S. While the figure shows the case where the direction of the magnetic field on the right side is deflected to the right, the electron beams R, G and B are shown.

First, while the arrangement direction of the electron beams or the arrangement axis 5 has a rotational misalignment as shown in FIG. 14, two magnetic pieces 31 are formed as shown in FIG. When placed horizontally (of the CRT 10), FIGS.
4, the horizontal deflection magnetic field 3N at the neck side end 8N and the deflection directions of the electron beams R, G, B are hardly affected by the presence of the magnetic piece 31.

Then, from the state shown in FIG.
Is rotated about the tube axis Z (for example, clockwise as viewed from the tube surface 10S side) (as shown in FIG. 5), the horizontal deflection magnetic field 3N of the neck-side end 8N changes. As a result, the deflection directions of the electron beams R, G, and B (refer to the directions of the thick arrows in FIG. 5) can be made substantially the same. At this time, each electron beam R,
G and B are deflected by the above-described changed horizontal deflection magnetic field 3N (see FIG. 5) in the vicinity of the neck side end 8N, and as the electron beam advances toward the tube face side end 8S (horizontal deflection shown in FIG. 14). It is deflected by a horizontal deflection magnetic field which is not affected by the magnetic piece 31 (corresponding to the magnetic field 3). Therefore, the trajectory of the electron beam is corrected (moved) at the neck end 8N of the deflection yoke 8 so that all the electron beams R, G, and B are directed in the same direction. It can be deflected by the horizontal deflection magnetic field on the side of the tube-side end 8S which has not been received. As a result, the B-BOW misconvergence can be corrected by arranging and fixing the magnetic piece 31 at an appropriate position.

At this time, for example, when the (main surface of) the magnetic piece 31 is made rectangular as shown in FIG. 4 and the like, in other words, the longitudinal direction of the rectangle is aligned with the direction of the magnetic field at the center of the horizontal deflection magnetic field. For example, by arranging the magnetic pieces 31 so that the longitudinal direction is substantially perpendicular to the horizontal deflection axis (the direction of deflection of the central electron beam by the horizontal deflection magnetic field among the three), the horizontal yoke 8 formed by the deflection yoke 8 is formed. The rotation can be performed while the deflection magnetic field 3 is substantially maintained.

In particular, as shown in FIG.
B-BOW misconvergence can be corrected by arranging the two magnetic pieces 31 so that X and the arrangement axis 5 of the electron beam overlap. The horizontal deflection axis 3
Forming a state in which the NX and the array axis 5 of the electron beam overlap each other is a setting necessary for correcting B-BOW misconvergence, and as shown in FIG.
It is not always necessary that X and the axis connecting the two magnetic pieces 31 overlap (for example, a case where the horizontal deflection magnetic field 3N does not follow the rotation of the magnetic piece 31).

By using a magnetic material having good frequency characteristics, for example, a ferrite material as the magnetic piece 31,
B responds well to high frequency horizontal deflection magnetic fields
-A magnetic field distribution capable of correcting BOW misconvergence can be formed.

Further, according to the misconvergence correction by the B-BOW correction device 30, the electron beam and the electron gun (electron gun 2) are used as in the conventional B-BOW misconvergence correction method.
Since the positional relationship with the electronic lens is not lost, the focus does not decrease.

Second Embodiment Next, a color image display device 52 according to a second embodiment will be described with reference to FIGS. 6 and 7 correspond to the above-described side view of FIG. 1 and the rear view of FIG. 2, respectively. In addition, the same reference numerals are given to the same components as those described above, and the description is referred to.

As can be seen by comparing FIGS. 6 and 7 with the above-described FIGS. 1 and 2, the color image display device 52 is replaced with the B-BOW correction device 30 of the device 51, and is replaced with a Yv misconvergence device. A correction device (hereinafter, also referred to as “Yv correction device”) 40 is provided. This Yv correction device 40 is a B-BO
It has the same configuration as the W correction device 30. That is, Yv
The correction device 40 includes a flat plate member 42 having a through hole 43 corresponding to the through hole 33, and two (one pair) magnetic pieces 41 arranged on the main surface 42S of the flat plate member 42 in the same manner as the magnetic piece 31.
And a handle 45 corresponding to the handle 35. Note that, similarly to the case of the B-BOW correction device 30, the magnetic piece 4
The size, shape, arrangement position, rotation range, and the like of 1 are appropriately set according to the Yv misconvergence correction amount.

As shown in FIG. 6, the Yv correction device 40 is inserted into the neck 10N near the neck side end 8N of the deflection yoke 8. Note that, contrary to the illustration in FIG. 6, the Yv correction device 40 may be arranged with the magnetic piece 41 facing the tube face 10S. Further, the flat plate member 4
2 may be provided with an extended end 8T (see FIG. 3) at the neck end 8N of the deflection yoke 8 and inserted into it.

Next, a method of Yv misconvergence correction by the Yv correction device 40 will be described with reference to FIGS. 8 and 9 show the arrangement position of the magnetic piece 41 and
The vertical deflection magnetic field 6N near the neck end 8N of the deflection yoke 8 and the deflection directions (indicated by bold arrows) and deflection amounts (in the length of bold arrows) of the electron beams R, G, B by the magnetic field 6N. FIG. The vertical deflection magnetic field in the color image display device 52 is
In the vicinity of the neck side end 8N, for example, the state shown in FIG. 8 or FIG. 9 is shown, while the distribution continuously becomes similar to the vertical deflection magnetic field 6 in FIG. Change. For convenience of explanation, the directions of the magnetic field in the vertical direction toward the paper surface (accordingly toward the tube surface 10S) in FIGS. 8 and 9 are illustrated differently as in FIGS. 4 and 5.

The Yv misconvergence correction method by the Yv correction device 40 is basically the same as that of the B-BOW correction device 30 described above. That is, as shown in FIG.
When two magnetic pieces 41 are arranged in the vertical direction (of the CRT) with respect to a state in which the arrangement axis 5 of the electron beam has a rotational shift, the neck side end (as viewed from the tube surface 10S side) 8N
The distribution of the nearby vertical deflection magnetic field 6N is hardly affected by the magnetic piece 41. From this state, when the flat plate member 42 (for example, clockwise as viewed from the tube surface 10S side) is rotated around the tube axis Z (as shown in FIG. 9), the presence of the magnetic piece 41 causes a vertical deflection magnetic field. 6N, thereby making it possible to make the deflection amounts (vertical components thereof) of the electron beams R, G, B substantially equal. In addition, the deflection can be performed with a vertical deflection magnetic field (corresponding to the vertical deflection magnetic field 6 shown in FIG. 17) on the tube side end 8S side which is not affected by the magnetic piece 41. Therefore, similarly to the B-BOW correction device 30, the Yv misconvergence can be corrected by optimizing the arrangement position of the magnetic pieces 41.

At this time, for example, when the (main surface of) the magnetic piece 41 is made rectangular as shown in FIG. 8 or the like, in other words, the longitudinal direction of the rectangle is aligned with the direction of the magnetic field at the center of the vertical deflection magnetic field. For example, by arranging the magnetic pieces 41 such that the longitudinal direction is substantially perpendicular to the vertical deflection axis (the direction of deflection of the central electron beam by the vertical deflection magnetic field among the three), the vertical yoke 8 formed by the deflection yoke 8 is formed. The rotation can be performed while the deflection magnetic field 6 is substantially maintained.

In particular, as shown in FIG.
By arranging the two magnetic pieces 41 so that Y and the arrangement axis 5 of the electron beams are orthogonal to each other, the Yv misconvergence can be corrected. The vertical deflection axis 6NY
Is a setting necessary to correct the Yv misconvergence, and the axis connecting the vertical deflection axis 6NY and the two magnetic pieces 41 as shown in FIG. Does not necessarily need to be orthogonal.

At this time, in consideration of the fact that the frequency of the vertical deflection magnetic field is generally lower than that of the horizontal deflection magnetic field, for example, a silicon steel plate material can be sufficiently used as the magnetic piece 41. Therefore, by using an inexpensive magnetic material such as a silicon steel plate, the Yv correction device 40 and the color image display device 52 can be provided at low cost and low cost.

Further, according to the misconvergence correction by the Yv correction device 40, the electron beam (provided in the electron gun 20) is provided as in the conventional Yv misconvergence correction method.
Since the positional relationship with the electron lens is not lost, the focus does not decrease.

<Embodiment 3> Next, FIG. 10 and FIG.
And the color image display device 53 according to the third embodiment.
Will be described. 10 and 11 correspond to the above-described side view of FIG. 1 and the rear view of FIG. 2, respectively. As shown in FIGS. 10 and 11, the color image display device 53 includes both the B-BOW correction device 30 and the Yv correction device 40 described above. 10 and 11 show a state in which the B-BOW correction device 30 is disposed on the deflection yoke 8 side, but the positions of the correction devices 30 and 40 are interchanged, and Yv
The correction circuit 40 may be arranged on the deflection yoke 8 side.

B-BO in the color image display device 53
The method of correcting the W misconvergence and the Yv misconvergence is the same as that in each of the color image display devices 51 and 52 described above, and therefore the description thereof will be referred to.

At this time, when the arrangement positions of the correction devices 30 and 40 are optimized and arranged as shown in FIGS. 5 and 9 (the state after the adjustment), the magnetic piece 31 moves from the deflection axis 6NY of the vertical deflection magnetic field 6N. Since the magnetic piece 31 exists at a distant position, the influence of the magnetic piece 31 on the magnetic field near the vertical deflection axis 6NY of the vertical deflection magnetic field 6N is very small. Similarly, the influence of the horizontal deflection magnetic field 3N by the magnetic piece 41 on the magnetic field near the horizontal deflection axis 3NX is negligibly small. Therefore, the color image display device 53
According to the above, each distribution of the horizontal deflection magnetic field 3N and the vertical deflection magnetic field 6N can be controlled independently. That is, unlike the conventional color image display device 50, B-BOW misconvergence and Yv misconvergence can be independently corrected. Of course, according to the image display device 53, the focus of the electron beam does not decrease.

The color image display devices 51 to 51 described above
According to 53, B-BOW or Yv misconvergence is reliably corrected, and an image or a video with higher screen quality than the conventional image display device 50 can be displayed. Needless to say, the correction devices 30 and 40 can also exert the above-described effects even in a recent color CRT or color image display device in which the size and definition are increasing.

[0047]

According to the first aspect of the present invention, 1
By rotating the pair of magnetic pieces about the tube axis, the magnetic field distribution near the neck-side end of the deflection yoke in the color image display device can be controlled. That is,
By appropriately controlling and setting such a magnetic field distribution, B-
BOW misconvergence or Yv misconvergence can be corrected. At this time, unlike the conventional color image display device, the focus of the electron beam emitted from the electron gun does not decrease. Therefore, according to the color image display device, by arranging the magnetic pieces at appropriate positions, it is possible to display an image or a video with improved screen quality as compared with the conventional color image display device.

(2) According to the second aspect of the present invention, since the pair of magnetic pieces is fixed to the flat plate member, the flat plate member is rotated about the tube axis to thereby form the pair of magnetic pieces. The same rotation of the pieces can be easily performed without breaking the positional relationship (symmetrical relationship) between the two magnetic pieces.

(3) According to the third aspect of the invention, the distribution of the horizontal deflection magnetic field and the distribution of the vertical deflection magnetic field can be controlled independently of each other. That is, B-BOW misconvergence and Yv misconvergence can be corrected independently.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a color image display device according to a first embodiment.

FIG. 2 is a schematic rear view of the color image display device according to the first embodiment.

FIG. 3 is a schematic rear view for explaining another configuration of the color image display device according to the first embodiment.

FIG. 4 is a schematic diagram for explaining a method of correcting B-BOW misconvergence in the color image display device according to the first embodiment.

FIG. 5 is a schematic diagram for explaining a correction method of B-BOW misconvergence in the color image display device according to the first embodiment.

FIG. 6 is a schematic side view of a color image display device according to a second embodiment.

FIG. 7 is a schematic rear view of the color image display device according to the second embodiment.

FIG. 8 is a schematic diagram for explaining a Yv misconvergence correction method in the color image display device according to the second embodiment.

FIG. 9 is a schematic diagram for explaining a Yv misconvergence correction method in the color image display device according to the second embodiment.

FIG. 10 is a schematic side view of a color image display device according to a third embodiment.

FIG. 11 is a schematic rear view of the color image display device according to the third embodiment.

FIG. 12 is a schematic diagram for explaining B-BOW misconvergence.

FIG. 13 is a schematic diagram for explaining another mode of B-BOW misconvergence.

14 is a schematic magnetic field distribution diagram for explaining the B-BOW misconvergence shown in FIG.

FIG. 15 is a schematic magnetic field distribution diagram for explaining the B-BOW misconvergence shown in FIG.

FIG. 16 is a schematic diagram for explaining Yv misconvergence.

17 is a schematic magnetic field distribution diagram for explaining Yv misconvergence shown in FIG.

FIG. 18 is a schematic side view of a conventional color image display device.

[Explanation of symbols]

3,3N horizontal deflection magnetic field, 3X, 3NX horizontal deflection axis,
5 Alignment axis of electron beam, 6, 6N vertical deflection magnetic field, 6
Y, 6NY vertical deflection axis, 8 deflection yoke, 8N neck side end, 8S tube side end, 8T extended end, 9
CP-ASSY, 10 CRT, 10N neck, 1
0S tube surface, 20 in-line type electron gun, 30 BB
OW misconvergence corrector, 31, 41 Magnetic piece, 32, 42 Plate member, 32S, 42S Main surface, 3
3, 43 through hole, 35, 35 handle, 40 Yv misconvergence corrector, 51 to 53 color image display, R, G, B electron beam, Z tube axis.

Claims (3)

[Claims] 1. A color CRT having an in-line type electron gun at its neck, a deflection yoke mounted on the color CRT, and an end of the deflection yoke on the neck side perpendicular to a tube axis of the color CRT. At least one is disposed symmetrically with respect to the tube axis on a plane close to the portion, and is arranged to be rotatable about the tube axis in the plane while maintaining the symmetric relationship. A color image display device comprising: a pair of magnetic pieces. 2. The color image display device according to claim 1, further comprising a flat plate member inserted into the neck portion of the color CRT and having a main surface forming the flat surface. A color image display device, wherein a pair of magnetic pieces is fixed. 3. The color image display device according to claim 1, comprising two pairs of said magnetic pieces, wherein said two pairs of magnetic pieces are arranged so as to be capable of performing said rotation independently of each other. A color image display device.