KR100303852B1 - Convergence device for color braun tube of inline shape - Google Patents

Abstract

PURPOSE: A convergence device of an inline shape color braun tube is provided to conveniently control static convergence within a permit range. CONSTITUTION: A 4 polar pair(P4) contains a first magnet ring. The 4 polar pair moves beams toward a reverse direction of each other. An electronic beam(20) is converged to a point of a phosphor face(40) through a shadow mask(30) in a raster state. The electronic beam scans the position of the phosphor face through a horizontal and vertical deflection unit(50). The magnet ring is composed of different polar. The pair controls the relative angle of the magnet ring to control the convergence through controlling movement of the beam. Thereby, a convergence device of the inline shape color braun tube conveniently controls the static convergence within a permitted range. Moreover, the convergence device of the inline shape color braun minimizes movement of the beam.

Description

Convergence device of in-line color brown tube

The present invention relates to an in-line type CRT, and more particularly to a convergence device thereof.

In-line color CRT forms three electron guns in which the electron gun assembly is arranged side by side. As shown in FIG. 1, the electron beam 20 emitted from the three electron guns 10 is in a raster state. It should be converged to a point on the fluorescent surface 40 through a shadow mask 30.

In this case, the electron beam 20 scans each position on the fluorescent surface 40 by horizontal and vertical deflection means 50. In this scanning, three electron beams 20 should be converged at one point at each position.

Accordingly, the color-brown tube is provided with static and dynamic convergence means, which are referred to collectively as P, P2, P4 and P6; It is generally composed of a convergence device called CPM (Convergence Purity Magnet).

Here, each pair P2, P4, P6 of the convergence device is partially magnetized and is composed of two magnet rings forming two kinds of poles, N and S.

First, the bipolar pair P2 shown in FIG. 2A is called a purity magnet. As shown in FIG. 2A, the three R, G and B beams are generated by the magnetic flux between the N pole and the S pole. Will move in one direction.

Meanwhile, the 4-pole pair P4 shown in FIG. 2B moves two R and B beams in opposite directions to each other. The two beams are moved in the same direction, and the 4-pole pair P4 and the 6-pole pair P6 are called convergence magnets together.

The convergence device is used to adjust the three R, G, B electron beams are not aligned correctly due to errors in the manufacturing process of the color CRT, each pair (P2, P4, P6) is composed of a pair of magnet ring The reason for this is to adjust the convergence by adjusting the beam shift amount for different manufacturing errors for each CRT by adjusting the relative angle therebetween.

That is, as shown in FIG. 3, a pair of pairs P of electrons entered by positioning the N pole and the S pole of the two rings R1 and R2 to correspond to each other through a spacer A is provided. By deflecting 20 twice, the landing position on the fluorescent surface 40 is adjusted.

However, since the CRT to be adjusted by the convergence device has a deviation amount of various sizes within the allowable tolerance, there are some unnecessary adjustments of the convergence depending on the CRT. In this case, the presence of the convergence device rather impairs the alignment of the CRT. As the precision of CRT production is improved, the characteristics of the convergence device become more important than the maximum beam displacement. Accordingly, the development of the conventional convergence device has mainly focused on minimizing the minimum beam shift amount.

3 is disclosed in US Pat. No. 4,570,140. The magnetic flux density of the first ring R1 on the electron gun side is larger than the second ring R2 on the fluorescent surface side so as to reduce the minimum beam shift amount.

That is, as shown in Fig. 4A, the magnetic flux density of the first ring R1 is magnetized so as to be larger than the magnetic flux density of the second ring R2, and as shown in Fig. 4B, a positive pair ratio is obtained. (HL) / L × 100%. In this case, the minimum beam shift amount is a beam shift amount at an outer end of a predetermined use error range.

Meanwhile, Korean Patent Publication No. 96-11769 has been disclosed as a technique for further reducing the minimum beam shift amount, which is shown in FIG. 5 (A), and the magnetic flux density of the second ring R2 is determined by the magnetic flux of the first ring R1. It is composed of inverse pairs by magnetizing higher than density, and each pole of the second ring (R2) is composed of a combination of a main magnetizer and a harmonic-shaped sub-magnet of the main magnetizer. The minimum beam shift amount is set to zero by forming a plurality of fine N and S poles during the minimum adjustment.

However, as shown in FIG. 5 (B), the width of the pole of the second ring R2 is narrowed to increase the slope of the beam shift amount graph, so that the beam moves largely even with a slight rotation, thereby making it very difficult to adjust the convergence. In addition, the minimum beam shift amount at the outer end of the use error range is rather increased than in the case of FIG. 4.

On the other hand, in consideration of the difference in the effective magnetic flux density according to the thickness difference between the two rings constituting a pair, Japanese Patent Publication No. 55-30659 has a magnetic flux density of which the N pole is larger than the S pole as shown in Figs. 6 (A) and (B). When the two rings R1 and R2 are magnetized to each other, the two rings R1 and R2 overlap each other by 90 °, so that R, G and B do not affect the electron beam as shown in FIG. A technique for zeroing the minimum beam shift amount has been disclosed.

However, the configuration of FIG. 6 is merely a theory without considering the actual magnetic flux distribution, and it is difficult to expect a practical effect.

However, the pairs P of each type of FIGS. 3 to 6 have a common point of axial symmetry in spite of the difference in the methods. These axisymmetric pairs P cause the following common problems in convergence adjustment.

First, look at the geometric definition of the three R, G, B electron beam to be adjusted through FIG. First, the distance between the electron beams R and B at the outer end is indicated by OCV, and the distance between the center of the distance between the electron beams R and B at the outer end and the central electron beam G is indicated by CCV. Here OCV is adjusted by 4 pole pairs and CCV is adjusted by 6 pole pairs.

Then, when the distance (OCV) between the outer electron beams R and B is within a predetermined range and the distance between the centers (CCV) is 0, theoretically, the three beams are completely matched. In practice, the tolerance of the distance between R and B (OCV) is 0.2mm, for example, and the tolerance of the center distance (CCV) is set to 0.05mm. When three beams are matched within this range, full convergence adjustment is made. Becomes

However, the axisymmetric pairs of FIGS. 3 to 6 cause problems as shown in FIG. 8.

First, a process of adjusting a CRT having a matching characteristic as shown in FIG. 7 to a 4-pole pair () as shown in FIG. 8 (A) will be described.

Theoretically, according to the four-pole pair P4, the two outer beams R and B should move in a solid line with respect to the center beam G by the N-S magnetic flux, so that the distance (OCV) between the R and B should be reduced.

However, since each pair P2 is composed of a combination of two rings R1 and R2, in order to adjust the magnitude of the magnetic flux density, the two rings R1 and R2 must be rotated relatively, so the direction of the magnetic flux is N'-S from NS. ', So that the outer beams R, B move in a dashed-line direction, that is, in an oblique line direction, rather than a solid line.

That is, since the R beam moves to the upper right and the B beam moves to the lower left, the R and B beams must be moved again in the up and down directions in order to place the R, G and B on the horizontal line.

This problem also applies to the six-pole pair P6 of FIG. 8B, and the two outer beams R and B, once adjusted by the four-pole pair P4 of FIG. 8A, are rotated in the magnetic flux direction. Since it moves to the lower left, it must be moved upward again as a whole.

Accordingly, the conventional axisymmetric pairs P4 and P6 excluding the two-pole pair P2 cause a shift in which adjustment is necessary for each adjustment, so that the multiple repetitions of the adjustment in FIGS. 8A to 8B are repeated. This makes it very difficult to adjust convergence.

In addition, as shown in FIG. 9, the minimum adjustment OCV between the two outer beams R and B is the sum of the respective minimum beam shift amounts. For example, if the minimum beam shift amount of the pairs of FIGS. 3 and 4 is 0.15 mm, the minimum adjustment OCV is performed. The OCV is twice that of 0.3 mm, which is larger than the allowable OCV 0.2 mm necessary for the function of the CRT, which causes a problem of deterioration of image quality such as color purity of the finished CRT. This problem also occurs in the adjustment of CCV by 6-pole pairs.

An object of the present invention is to provide a convergence device for an in-line color brown tube that can easily adjust and achieve a minimum adjustment state within an acceptable range.

1 is a schematic cross-sectional view showing the configuration of an inline color brown tube,

2a to 2c are schematic views showing the function of each pair of convergence devices,

3 is a beam path diagram showing the action of a conventional pair,

4a is a magnetization state diagram of the pair of FIG. 3, FIG. 4b is a graph of the beam shift amount,

5a and 5b are a graph of the magnetization state and the beam shift amount of another conventional pair,

6a to 6c is a schematic view showing the configuration and operation of another conventional pair,

7 is a graph showing the geometric definition of three beams to be adjusted by the convergence device,

FIG. 8 is a view showing adjustment problems with a conventional large pair. FIG. 8A is a 4-pole pair, FIG. 8B is a 6-pole pair.

9 is a view showing a minimum beam shift amount by a conventional pair,

FIG. 10 is a diagram illustrating a four-pole pair according to the present invention. FIGS. 10a and 10b are views of two rings forming a pair, and FIG. 10c is a magnetization state of one ring.

FIG. 11 is a diagram illustrating a six-pole pair according to the present invention. FIGS. 11a and 11b are views of two rings forming a pair, and FIG. 10c is a magnetization state of one ring.

12 is a graph of a minimum beam shift amount according to the present invention,

13 and 14 are views for explaining the operation of the four-pole pair and six-pole pair of the present invention,

15 is a view showing the adjustment characteristics according to the present invention, Figure 15a is a fourth pole pair, Figure 15b is a view for the six-pole pair,

16 is a view showing a minimum beam shift amount according to the present invention,

17A and 17B show another pair according to the present invention.

* Explanation of symbols for main parts of the drawings

P2: 2 pole pair

P4: 4-pole pair

P6: 6 pole pair

R1, R2: (magnet) ring (of each pair)

(Classified as 1st and 2nd ring)

N, S: N and S poles

In the convergence device of the present invention for achieving the above object, when at least one ring of each pair is divided into two about its central axis, at least one pole of one half is magnetized with a lower magnetic flux density than the opposite pole of the other half. It is characterized in that the asymmetrical configuration.

According to a preferred feature of the invention, the other ring of each pair is also configured asymmetrically, magnetizing in opposite polarity with this ring.

According to this configuration, when the 4-pole and 6-pole pairs are configured, the amount of movement of the R and B beams at the outer ends is asymmetric, that is, one side is large and the other side is small.

This allows for quick and easy convergence adjustment and achieves a minimum adjustment within the acceptable range.

Such specific features and advantages of the present invention will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

10 and 11 illustrate a 4-pole pair P4 and a 6-pole pair P6 according to the present invention. First, the 4-pole pair P4 of FIG. 10 will be described.

In the four-pole pair P4, the first ring R1 of FIG. 10 (A) has two S and N poles on the right half more than two opposite N and S poles on the left half when divided into two along the upper and lower center axes. The second ring R2 of FIG. 10 (B) is magnetized to a low magnetic flux density and the left half is magnetized to the S and N poles, and the right half is magnetized to the N and S poles of low magnetic flux density. Magnetized in the opposite polarity to the ring (R1).

Accordingly, the overall magnetization state becomes H-H-L-L as shown in FIG. 10 (C).

On the other hand, the six-pole pair P6 shown in FIG. 11 has a magnetic flux density lower than that of the upper left NSN pole than the upper left SNS pole, similar to FIG. 10, and the first ring R1 of FIG. It consists of the 2nd ring R2 of FIG. 11 (B) magnetized by the opposite polarity, and has the magnetization state of HHHLLL like FIG. 11 (C).

As described above, the pairs P4 and P6 according to the present invention exhibit a beam shift characteristic as shown in FIG. 12 because the poles in each ring R1 and R2 have an asymmetric difference in magnetic flux density.

In FIG. 12, the beam shift amount graph is shown as double, unlike FIGS. 4 to 5, that is, a graph of a large inward slope between the poles of relatively high magnetic flux density, and a graph of a small slope of the outside between the poles of the relatively low magnetic flux density. Appears. That is, two large and small beam shifts can be displayed in the same pair P4 and P6. When both rings R1 and R2 of the pair P2 and P4 are configured with magnetic flux densities corresponding to each other, the pair ratio Becomes 0, and as will be described later, the pair of the present invention achieves zero OCV and zero CCV, so the final error range becomes ± tolerance range.

To clarify this, let's look at the behavior of 4-pole and 6-pole pairs and the achievement of zero OCV and CCV.

First, FIG. 13 shows the configuration of the four-pole pair P4. As shown in (A), since the S and N poles of the right half portion have lower magnetic flux densities than the N and S poles of the left half portion, The speed right half is smaller than the left half, so that the right beam shift amount becomes smaller than the left beam shift amount as shown in (B).

Meanwhile, in the six-pole pair P6 of FIG. 14, the right-beam shift amount is smaller than the left-beam shift amount in the same manner as in the four-pole pair P4.

13 and 14, since the poles of the small magnetic flux density are arranged in the right half, the right beam shift amount becomes smaller than the left beam shift amount, but the opposite is also true, and the two rings R1 and R2 of each pair P4 and P6 are arranged. ) Are magnetized in opposite polarities so that the amount of movement of either the left beam or the right beam can be set small according to the need of adjustment.

Such a process of adjusting convergence by the asymmetric pair of the present invention will be described with reference to FIG. 15.

FIG. 15 (A) is a diagram of a four-pole pair P4 for adjusting OCV by moving two outer beams R and B in opposite directions. In the conventional symmetric pair, a change in magnetic flux direction during adjustment by relative rotation of the ring is shown. As a result, the R and B beams are moved in the opposite directions by the same size to the R1 and B2 positions.

However, in the asymmetric pair of the present invention, the B beam caused by the magnetic flux of the right half of the magnetic flux density is moved only by a relatively small distance to the B1 position.

Also in the six-pole pair P6 of Fig. 15B, the B beam on the right half side having a small magnetic flux density also moves only by a distance relatively smaller than that of the R beam.

This result shows that in the actual adjustment, when the R beam is shifted further from the G beam than the B beam, the magnetic flux density of the pairs P4 and P6 is placed on the R beam side and adjusted with the focus on the R beam. Since the amount of movement of the B beam is small, the overall convergence can be easily adjusted. On the other hand, if the B beam has a larger shift, the overall convergence can be achieved by rotating the pairs P4 and P6 in reverse and focusing on the B beam.

Here, the magnetic flux density of the poles of one half is lower than the magnetic flux density of the poles of the other half, the magnetic flux density of the other half has a general magnetic flux density of the conventional pairs of FIGS. 3 to 5 and the magnetic flux density of one half is lower than this. Is meant.

For example, when the magnetic flux density of the other half is set to 100G, which is a general size, and the magnetic flux density of one half is 50G, which is half of that, the amount of beam movement by the one half is 1/2 of the other half, and the minimum beam shift is 1 as well. / 2.

Accordingly, as shown in FIG. 16, the minimum adjusted OCV is the sum of the minimum movement amount of the left beam and the minimum movement amount of the right beam. In the example of FIG. 9, the minimum adjustment OCV is 0.225 mm, which is the sum of 0.15 mm and the half of 0.075 mm. It can be seen that it is slightly larger than the allowable OCV of 0.2mm.

In this case, it can be seen that when the magnetic flux density of the left half is higher than 100G or the magnetic flux density of the right half is lower than 50G, a minimum adjusted OCV of 0.2 mm or less, which is an allowable OCV, can be achieved.

This effect can be similarly applied to the adjustment of the CCV. In the end, unlike the prior arts in which the present invention has attempted to improve the characteristics of the pair itself to reduce the minimum beam shift, the poles in the pair have an asymmetrical magnetic flux density. The minimum beam shift is limited within the allowable range, i.e., zero OCV and zero CCV are achieved.

In the above description, each pair is divided into two to illustrate configurations in which the poles of one half are lower in magnetic flux density than the poles of the other half. However, these two splits are not essential to the features of the present invention, and are easy to manufacture or adjust. Rather, it is more practically preferable to configure only one or two poles to have a magnetic flux density that is larger or smaller than other poles including the opposite poles.

For example, in FIG. 17, the two rings R1 and R2 of (A) and (B) constituting the 6-pole pair P6 have the upper and lower N poles and the S poles larger than the other poles (or vice versa). ) It is magnetized with magnetic flux density.

Table 1 below shows the measurement result of the minimum beam shift amount on the fluorescent surface when the small magnetic flux density pole is positioned at the position adjacent to the B beam among the outer beams. The result of Table 2 is a convergence device according to Hitachi's U.S. patent shown in FIGS. 3 and 4.

<Table 1>

<Table 2>

As can be seen from the above, it can be seen that according to the present invention, it is possible to shift the asymmetry of the two outer beams so that zero OCV and CCV can be easily achieved as described above.

At this time, the asymmetrical movement is caused by the difference in magnetic flux density between the pole having the low magnetic flux density and the pole of the opposite side, and when expressed as a ratio, the magnetic flux density difference is preferably 5% to 95% of the opposite pole. Here, the lower limit of 5% is a limit of an error that a change of magnetic flux density may occur when magnetizing and using, and the upper magnetic flux distribution may be excessively distorted at an upper limit of 90%, making adjustment difficult. In this case, the magnetic flux density is generally measured at a position 5.5 mm away from the inner ends or the centers of the rings R1 and R2.

Meanwhile, the present invention has been described mainly through the 4-pole pair (P4) and the 6-pole pair (P6), but the present invention is similarly applied to the 2-pole pair (P2) to achieve the effect of asymmetrical adjustment, but the 2-pole In the pair P2, the problem of symmetrical movement during adjustment as in the 4-pole and 6-pole pairs P4 and P6 does not occur, so there will be no great advantage in the application thereof. However, according to the experiment of the present invention, the magnetic flux density of the two poles in the divided position with respect to the center of the ring constituting the 4-pole pair P4 is 30 to 65% based on one pole. Preferably, the magnetic flux density of the two poles in the bisected position based on the center of the two rings constituting the 6 pair (P6) is 20 to 50% based on the pole of one side there was.

As described above, the convergence device of the in-line color CRT according to the present invention has a difference in magnetic flux density of the poles positioned at both sides with respect to the center of each of the two rings constituting the 2, 4, 6 pole pairs. Since the minimum electron beam displacement that is shifted by the relative rotation of can be converged to 0, the adjustment of the static convergence is very easy and there is a great effect of achieving the convergence within the allowable range.

The magnet assembly for adjusting the movement path of the electron beam of the cathode ray tube of the present invention is not limited to the above-described embodiment and can be modified by those skilled in the art within the technical scope of the present invention.

Claims (7)

In the convergence device of the in-line color brown tube having at least one pair each consisting of a pair of magnet rings, When the at least one magnet ring of each pair is divided into two centers around its central axis, the magnetic flux density of at least one pole of one half is lower than the magnetic flux density of the pole of the opposite side of the other half so that it is asymmetrically configured. Convergence device of inline type CRT. The method of claim 1, And the other magnet ring of each pair is configured to have an asymmetrical polarity opposite to that of the magnet ring. The method of claim 1, And said low magnetic flux density pole has a magnetic flux density difference of 5 to 90% with respect to the magnetic flux density of the opposite pole. The method of claim 1, The magnetic flux densities of the poles at the positions divided by the center of the magnet rings are different from each other, and the two poles on the mutually opposite sides of each magnet ring are identical to each other in a state where the pair of magnet rings are not rotated with each other. An in-line type CRT converging device, characterized in that it is magnetized to have a magnetic flux density. The method of claim 1, And said magnet rings are magnetized into 4 or 6 poles. The method of claim 5, Convection of inline type CRT tube, characterized in that the difference in magnetic flux density of the two poles in the bisected position on the basis of the center of the magnet ring magnetized into each of the four poles is 30 to 65% based on one pole Device. The method of claim 5, Convection of inline type CRT tube, characterized in that the difference in the magnetic flux density of the two poles in the bisected position based on the center of the magnet ring magnetized into each of the six poles is 20 to 50% based on the one pole Device.