KR20010068566A - Convergence device for a color picture tube - Google Patents

Abstract

PURPOSE: A convergence divide of a color CRT is provided to compensate a heating drift without decreasing convergence characteristics by applying a preferred construction for easily performing an adjustment. CONSTITUTION: The convergence divide of a color CRT includes the first and the second heat pulse magnetic substance(P4a,P4f) which are sequentially arranged in front and afterward of a holder, respectively. The first heat pulse magnetic substance(P4a) is alnico material which temperature variation coefficient is 0.012 %/°C, while the second heat pulse magnetic substance(P4f) is a conventional ferrite material which temperature variation coefficient is 0.2 %/°C. Also, the magnetic poles of the first and the second heat pulse magnetic substance(P4a,P4f) are contrary arranged each other to inversely perform a focus and a diffusion operation.

Description

Convergence device for a color picture tube}

The present invention relates to a convergence device of a color CRT.

The color CRT, which realizes a color image, has an aperture type that alternately emits R, G, and B phosphors in a single beam, a trio type in which three independent electron guns are arranged in a trio form, and The three electron guns can be distinguished in an in-line arrangement in which they are laterally arranged.

Among them, trio type and upper type are mainly used for industrial color brown tube such as monitor, and inline type is mainly used for consumer use such as color TV.

In-line color CRT forms an electron gun assembly 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 gun 10 is in a raster state. Through a shadow mask 30 it must be converged to a point on the fluorescent surface 40 (actually a position on the corresponding phosphor in one pixel, i.e. three fluorescent points in one pixel).

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

Accordingly, the color-brown tube is provided with static and dynamic convergence means, and the static convergence means are referred to as three pairs of two poles, four poles and six poles (P2, P4, 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 consists of two magnet rings forming two types of poles, N and S.

First, the bipolar pair P2 shown in FIG. 2 (A) is called a purity magnet, and as shown in FIG. 2A, 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.

On the other hand, the four-pole pair P4 shown in FIG. 2 (B) moves the two R and B beams in opposite directions to each other, and the six-pole pair P6 of FIG. 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. 2 (B) and (C) are particularly shown by the present invention of the present inventors who made the 4-pole pair P4 and the 6-pole pair P6 asymmetrical magnetic fields to facilitate the adjustment of the electron beam.

In this case, the convergence device adjusts the R, G, and B three electron beams to be not aligned correctly due to an error in the manufacturing process of the color CRT, and adjusts the landing to exactly one point on the screen. The reason why P2, P4, P6) is composed of a pair of magnet rings is to adjust the convergence by adjusting the beam shifting amount for different manufacturing errors for each CRT by adjusting the relative angle therebetween.

However, since the electron beam in the electron gun is formed by focusing and accelerating hot electrons generated by heating of the heater, high heat is generated during operation of the electron gun, and thus, the electrodes constituting the electron gun have to be thermally deformed. Referring to FIG. 11, the electron beam B1 is focused and accelerated by the electrodes and is landed on the screen S as a beam Bc adjusted by the convergence device in a state where no thermal deformation occurs. When the electrode is heated by heating of the heater, the electron beam Bf diffuses and lands on the outside of the screen, and the difference in the landing position at this time becomes the thermal drift displacement amount f. In particular, this thermal drift displacement changes over time from the beginning of the operation of components such as electrodes to sufficient heating, thus impeding the acquisition of stable and clear images.

On the other hand, in the past, the material constituting the electrode has been mainly composed of a material with a small thermal deformation as much as possible, but this effect was not sufficient even though it requires enormous expenses in the development of the material, and conversely, the processability of the material This lowered the yield of the electron gun and caused a problem of raising the manufacturing cost.

One method proposed as an effective alternative to thermal drift is a method of using a so-called thermal stimulating magnetic material using a phenomenon that the magnetic force is lowered with the rise of temperature, which will be described with reference to FIG. 12.

In the left half of Fig. 12, for example, a thermal stimulus magnetic body P4f having a magnetic force of 10 is attached to the outer periphery of the electron beam path, that is, the convergence device, to enlarge the OCV which is the horizontal distance between the three electron beams R, G, and B. have. In the right half of Fig. 12, when the electron gun is heated, the electrode indicated by the dotted line region is thermally deformed, and the thermal magnetic pole body P4f is also heated. At this time, the magnetic force of the thermal magnetic stimulus (P4f) is reduced from 10 to 8, for example, the amount of expansion of the OCV is relatively reduced, thereby reducing the amount of thermal drift displacement.

Here, the thermally stimulating magnetic material P4f may be made of a ferrite-based material having a large change in magnetic force according to a change in temperature, but it has various problems as follows.

First, since the compensation of the thermal drift depends only on the physical properties of the thermal stimulating magnetic material P4f, the amount of compensation is not large. For example, the amount of thermal drift displacement f generated in a typical inline CRT is about 0.3 mm, but the drift that the ferrite thermal magnetic material P4f can improve is only 0.1 mm.

In addition, since the thermal drift compensation structure diffuses the OCV in advance and decreases the diffusion amount according to the temperature change, the premise of the expansion of the OCV makes the design and configuration of the convergence device very difficult. That is, in the current state of the art, when the horizontal distance between the three electron beams (R, G, B), OCV is in the range of 1.5 to 2 mm, the configuration and adjustment of the convergence device can be easily performed. However, according to the conventional thermal drift compensation structure, the OCV becomes larger by about 1 to 2 mm by the use of the thermal stimulus magnetic body P4f, which inevitably increases the magnetic force of the magnetic poles constituting the convergence device. It causes problems.

For example, when the pure OCV of the electron gun is 2 mm and the OCV of the beam rotation magnet of the deflecting device is 2 mm, if the OCV of the thermal stimulating magnetic body P4f is 2 mm, the overall OCV is 6 mm. In order to adjust the 6 mm OCV, the required adjustment amount of the OCV of the magnet ring that will constitute the convergence device is 6 mm or more, and considering the deviation ± 1 mm in the manufacturing process of the part, a required adjustment amount of 8 mm or more is required. Have.

When the required adjustment amount is 8 mm or more, which is much larger than the ideal adjustment amount of 1.5 to 2 mm, the magnet ring having a large magnetic force is forced to use, so that the influence of the magnetic force is applied to other beams as well as to the beam to be adjusted, thereby increasing the number of convergence adjustments. However, it is very difficult to obtain satisfactory adjustment results.

The magnet rings P2, P4, and P6 are configured as a pair as described with reference to FIG. 2, which will be described in detail with reference to FIGS. In Fig. 18A, for example, the four-pole pair P4 consists of a pair of magnet rings R1 and R2 each with a handle H, initially coinciding with each other as shown in Fig. 18B. This is assembled to the convergence device in the magnetic field. The adjusting operator adjusts the convergence by rotating the handle H to adjust the relative angles between the magnetic poles N and S on the two magnet rings R1 and R2. 19 is an example in which the OCV is adjusted by a magnetic force corresponding to a relative angle of 30 degrees, for example, and FIG. 20 shows a relative angle of 90 degrees that exhibits the maximum magnetic force.

In the above drawings, each magnetic pole (N, S) is ideally shown to affect only the outer electron beam (R or B) adjacent to it, but when the magnetic force increases, not only one outer beam (R or B) but also the central beam (G) Magnetic force is also applied to the other beam B or R to change its path, making adjustment of convergence very difficult. In addition, even with a slight adjustment of the handle H due to a large magnetic force, the convergence is greatly changed, so that fine adjustment of, for example, 0.05 mm or less is impossible.

Accordingly, the conventional technique using the ferrite thermal stimulus magnetic body (P4f) not only has a limitation in the compensation of thermal delift, but also makes it difficult to adjust the convergence and degrades the convergence state, thereby providing a satisfactory technical alternative to thermal drift. I can't.

In view of the above-described conventional problems, an object of the present invention is to provide a convergence device capable of compensating for thermal drift without degrading the convergence characteristic.

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

2 (A) to (C) are schematic diagrams showing the function of each pair of convergence devices;

3 and 4 are schematic views showing the structure of the convergence device of the present invention,

5 and 6 is an assembled plan view and side view of the present invention,

7 and 8 are a plan view and a side view showing the configuration of the holder of Figs.

9 (A) to (B) are plan views showing a preferred configuration of the first thermal stimulus magnetic body of the present invention,

10 is a plan view showing a preferred configuration of the second thermal stimulation magnetic body of the present invention,

11 is an electron beam path diagram showing a principle of occurrence of thermal drift;

12 is an electron beam path diagram illustrating a principle of operation of a conventional thermal drift compensation means.

13 to 15 are electron beam path diagrams explaining the principle of operation of the thermal drift compensation means according to the present invention;

FIG. 16 is an electron beam path diagram briefly explaining an operation principle of a conventional thermal drift compensation means for comparison with FIG. 17;

17 is an electron beam path diagram for explaining the operation principle of another configuration of the thermal drift compensation means according to the present invention;

18 to 20 are plan views illustrating a principle of adjusting the convergence of the magnet ring.

<Description of the symbols for the main parts of the drawings>

P4a: first thermally stimulating magnetic material

P4f: second heat stimulating magnetic material

D: holder

P2, P4, P6: (adjustable) magnet ring

Convergence device according to the present invention to achieve the above object,

A first thermal stimulus magnetic body consisting of a magnetic material having a relatively small temperature change coefficient and a second thermal stimulation magnetic body having a relatively large temperature change coefficient are sequentially arranged on the path of the electron beam.

Preferably, the first and second heat stimulating magnetic bodies interact with each other in diffusion and focusing, the first heat stimulating magnetic material is made of Al-Ni-CO, and the second heat stimulating magnetic material is made of ferrite. .

According to this configuration, since the deterioration of the magnetic force of the two thermal stimulation magnetic material occurs at the same time when heating the thermal stimulation magnetic material, at the same time the amount of diffusion of one thermal stimulation magnetic body and at the same time reducing the amount of focus of different thermal stimulation magnetic body and Since the compensation of the geometric path is made, it is possible to keep the path of the electron beam almost constant despite the change in temperature.

As a result, the present invention provides a convergence device that is easy to adjust and that the configuration of the convergence device is very easy.

Example

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.

3 and 4 respectively show a preferred embodiment of the convergence device of the present invention, each of the pair of magnet rings (P2 to P4 in FIG. 2) for the convergence adjustment around the neck (N) of the CRT. However, for convenience, instructions are omitted) and holders (D) are installed. The first thermally stimulating magnetic body P4a and the second thermally stimulating magnetic body P4f according to the present invention are sequentially arranged before and after the holder D, i.e., before and after the path of the electron beam. This convergence device may be attached to the deflection device according to the configuration, and even if the convergence device is attached to the neck N, the following configuration of the present invention is independently attached to the deflection device as needed as in the case of components of other convergence devices. May be

Here, the first thermal magnetic stimulus P4a and the second thermal magnetic stimulus P4f are preferably made of materials having different temperature change coefficients. For example, the first thermal magnetic stimulus P4a positioned forward in the electron beam path. ) Is composed of, for example, an alnico material having a temperature change coefficient of 0.012% / ° C., and the second thermal stimulating magnetic material P4f is formed of a conventional ferrite material having a temperature change coefficient of 0.2% / ° C., for example. More preferably, the first thermal stimulating magnetic body P4a and the second thermal stimulating magnetic body P4f are arranged with opposite magnetic poles so that focusing and diffusion are opposite to each other, and the first thermal stimulating magnetic body having a small temperature change coefficient will be described later. It is preferable that the second thermal magnetic stimulus P4f having a high focusing coefficient and a temperature change coefficient (P4a) have a diffusion effect.

The principle of such a configuration and operation will be described with reference to FIG. 13. In the left half of FIG. 13, the first thermal magnetic stimulus P4a and the second thermal magnetic stimulus P4f before the heating are formed to have the same magnetic force 10, and have the opposite effect of focusing and diffusion. Accordingly, the OCV of the electron beam landing on the screen S has almost the same OCV as the original OCV, but actually has a slightly larger OCV.

Next, when the electrode is heated in the right half of FIG. 13, the electron beam is diffused outward along the path of B1 due to thermal deformation thereof, and then inwardly deflected inward by the path of B2 by the first thermal stimulating magnetic body P4a ( Viii) The electron beam of B2 is then diffused by the second thermal stimulus magnetic material P4f and landed on the screen S in the path of Bc to compensate for the thermal drift.

Here, since the first thermal magnetic stimulus P4a and the second thermal magnetic stimulus P4f are essentially the same magnetic force, if there is no decrease in magnetic force due to heating, the amount of drift displacement will be generated along the path of Bf indicated by the dotted line. Since the magnetic force of the second thermal stimulus magnetic body P4f having a relatively large temperature change coefficient becomes 8, for example, the diffusion amount is reduced and landing is performed in the path of Bc which is in a substantially converged state.

On the other hand, the magnetic force of the first thermal magnetic stimulus (P4a) is still displayed as 10 after heating, which means that the temperature change coefficient is smaller than the second thermal stimulus (P4a). Here, the reason why the first thermal magnetic stimulus (P4a) is relatively small, but the magnetic force should be changed according to the temperature so that the OCV of the electron beam is not excessively reduced by the large decrease in the diffusion amount of the second thermal stimulation magnetic substance (P4a) during heating. This is because it is necessary to adjust the connection amount by alleviating the inner inflection of the path.

5 and below show embodiments that actually configure such a convergence apparatus of the present invention. On the holder D shown in Figs. 5 and 6, the pairs P2, P4 and P6 of the magnet rings and the first and second thermal stimulating magnetic bodies P4a and P4f according to the present invention are mounted. Preferably, the second thermal stimulus magnetic body P4f is configured as a 4-pole C-shaped ring as shown in FIG. 10 and is connected to the holder D by a coupling jaw Hb as shown in FIGS. 7 and 8. Supported.

On the other hand, as shown in Figs. 9A and 9B, the first thermal magnetic pole body P4a is preferably formed of four poles in an O-ring shape. It can be composed of multiple poles. On the other hand, in the case of four-pole configuration as shown in FIG. 9 (A), the OCV can be adjusted, but since the vertical distance between the electron beams, CCV, is increased, so that the relative magnitude of the magnetic force between the magnetic poles (N, S) is preferably asymmetric. It is preferable to use the configuration of shift magnetization as shown in Fig. 9B.

The operation principle of the present invention as described above will be described with reference to FIGS. FIG. 13 is a case where the magnetic forces of the first and second thermal magnetic pole bodies P4a and P4f are the same, and FIG. 14 is a case where the magnetic force of the first thermal magnetic pole body P4a is greater than that of the second thermal magnetic pole magnet P4f. 15 illustrates a case in which the magnetic force of the first thermal stimulation magnetic body P4a is smaller than the magnetic force of the second thermal stimulation magnetic body P4f. On the other hand, the magnetic force of the second thermal stimulation magnetic body (P4f) has a large difference before and after heating, but the change of the magnetic force of the first thermal stimulation magnetic body (P4a) having a relatively large temperature change coefficient is considered to be little before and after heating for convenience. .

First, in the left half of FIG. 13, since the first thermal magnetic stimulus P4a and the second thermal magnetic stimulus P4f before heating have the same magnetic force, the electron beam maintains its original path by focusing and diffusion, and thus the degree of change of OCV. Few. On the other hand, when the electrode is expanded by heating, the electron beam is diffused in the path of B1 and then bent into the path of B2 by the focusing of the first thermal stimulus magnetic material P4a. In this state, if the magnetic force of the second thermal stimulus magnetic body P4f is maintained, it will be landed in the path of Bf indicated by the dotted line and the displacement amount will be generated as f. However, the magnetic force of the second thermal stimulation magnetic body P4f is reduced to 8 by heating. In this case, the thermal drift is compensated by landing on the screen S with the path of Bc which is approximately convergent.

Such an operation may be performed when the magnetic force of the first thermal stimulus magnetic body P4a is greater than the magnetic force of the second thermal stimulus magnetic body P4f as shown in FIG. 14, or the magnetic force of the first thermal stimulus magnetic body P4a is as shown in FIG. 15. The same principle applies to the case where the magnetic force of the thermal stimulus magnetic body P4f is smaller than the magnetic force. That is, since the physical properties of the first thermal magnetic stimulation (P4a) and the second thermal magnetic stimulation (P4f) is determined at the time of selection of the material, the relative strength of the magnetic force of the two thermal stimulation magnetic materials (P4a, P4f), not by the difference of these properties It is possible to relatively determine the amount of compensation for thermal drift.

On the other hand, Figs. 16 and 17 show the operation of the case where the first thermal magnetic stimulus P4a of the present invention is used alone. First, in FIG. 16, the conventional constitution is a four-pole or six-pole thermal stimulus P4f. ), The OCV is diffused in advance, and then the degree of diffusion is reduced by lowering the magnetic force during heating.

In contrast, in FIG. 17, the first thermal stimulus magnetic material P4a reduces OCV in advance, thereby compensating for diffusion of OCV due to expansion of the electrode during heating. At this time, since the temperature change coefficient of the first thermal stimulus magnetic body P4a is relatively small, the problem of deterioration or adjustment of the convergence characteristic due to the adoption thereof is hardly generated. In addition, since the compensation is not merely dependent on the physical properties of the first thermal magnetic stimulus (P4a), it is a geometric compensation considering the thermal expansion of the electrode in advance, so that appropriate compensation can be expected.

As described above, in the present invention, the thermal drift is compensated by the physical and geometric interactions of the two other thermal magnetic materials instead of relying on the physical properties of the thermal magnetic materials, so that excessive initial OCV is not required as in the conventional configuration. A sufficient amount of thermal drift can be compensated for without. While the conventional configuration requires an OCV adjustment amount of 8 mm, the compensation amount of the thermal drift is only 0.1 mm, while the present invention has a required adjustment amount within 5 mm while compensating all of the thermal drifts of 0.3 mm. As a result, the required magnetic force of the magnet is also not large, and the present invention enables fine adjustment within 0.05 mm and OCV adjustment in the range of 0.05 mm to 5 mm.

As a result, the present invention provides a convergence device that completely compensates for thermal drift but does not deteriorate the convergence characteristic and makes adjustment of the convergence very easy.

Claims (7)

In the convergence device of the inline type CRT, A first thermal stimulus magnetic body composed of a magnetic material having a relatively small temperature change coefficient, and a second thermal stimulus magnetic body having a relatively large temperature change coefficient are sequentially arranged on the path of the electron beam. The method of claim 1, And the first thermal stimulus magnetic body and the second thermal stimulus magnetic body reverse the focusing and diverging action with respect to the electron beam. The method of claim 1, And the first thermal magnetic pole body is positioned in front of the path of the electron beam than the second thermal magnetic pole body. The method according to any one of claims 1 to 3, And the first thermal stimulating magnetic body focuses the electron beam and the second thermal stimulating magnetic body diffuses the electron beam. The method of claim 1, Convergence apparatus of a color CRT tube, characterized in that the first thermal stimulation magnetic material is made of alnico material. The method of claim 1, Convergence apparatus of a color brown tube, characterized in that the second thermal stimulation magnetic material is made of a ferrite material. The method of claim 1, The first thermal magnetic pole body is composed of an O-type or C-type magnet ring having a plurality of magnetic poles, And a shift magnetization of the plurality of magnetic poles so as to be asymmetrical.