JP2685797B2 - Color picture tube device - Google Patents

Description

The present invention relates to a color picture tube apparatus, and more particularly to a color picture tube apparatus having good concentration characteristics of three electron beams on a screen. It is a thing.

(Prior Art) As for shadow mask type color picture tubes, those which are equipped with an in-line type electron gun and a slot type shadow mask are mainly used at present. This will be described with reference to FIG.

Such a so-called shadow mask, an in-line type color picture tube, as shown in FIG. 2, has a phosphor layer which emits R, G, B colors by an electron beam bombarding the inner surface regularly in a dot shape or a band shape. A face plate (1) on which the fluorescent screens (2) arranged in the above are formed, and a plurality of panel pins (5) planted on the inner wall of the side wall (1-1) of the face plate (1). A shadow mask (3) having a large number of openings (12) that are opposed to the fluorescent screen (2) at a predetermined interval via a spring (6) and a mask frame (4), and if necessary. An inner shield (14), a color picture tube body connected to a neck (9) that houses an electron gun (10) through a funnel (7) on a side wall (1-1), and a neck. The support portion (8-
The deflection device (8) fixed by 1) and attached via a wedge (8-2) between the funnel (7) and the outer wall, and the adjusting magnet (1) mounted on the neck (9) outer wall
In such a color picture tube composed of (1) and (3), the electron beam (13) emitted from the electron gun (10) passes through the opening (13) and causes a predetermined fluorescent layer on the fluorescent screen (2) to pass through. Make it glow.

The electron gun (10) forms R, G, and B electron beams that cause the phosphor layer that emits R, G, and B light to emit light, respectively. In these color image tubes, which are generally called three-beam shadow mask tubes, an electron gun in which three electron guns, which are called in-line electron guns, are lined up in a line in the horizontal direction, is predominant at present. In a color picture tube using such an in-line electron gun, each electron beam emitted by the R, G, B color phosphor layers emits a focusing electrode of the electron gun (10) when the deflection yoke (8) is not operated and no deflection is performed. It is designed to concentrate on one point on the fluorescent screen due to size and other factors.

In the in-line electron gun, the deflection yoke (8)
By appropriately designing the magnetic field of (3), the R, G, and B3 beams can simultaneously pass through one point of the shadow mask (3) at the time of deflection.

Such a magnetic field is well known as shown in JP-A-57-1857 and is generally employed. That is, the horizontal deflection magnetic field is a pincushion type magnetic field as shown in FIG. 3 (a), and the vertical deflection magnetic field is a barrel type magnetic field as shown in FIG. 3 (b). Even if it is not necessary, a good concentration characteristic of three electron beams (hereinafter referred to as a congence characteristic) can be obtained over the entire screen. However, when the deflection angle of the color picture tube becomes large, such as 100 ° and 110 °, the following convergence error becomes conspicuous. This cannot be corrected even if the characteristics of the pincushion of the horizontal and vertical magnetic fields and the barrel magnetic field, which are generally called cross characteristics of horizontal lines, are changed. This is described in the document "SST deflection yoke for inline high definition color tubes" (Technical Report ED619 of Iwasaki et al. Television Society). That is, in a saddle-toroidal deflection yoke that is usually used in large numbers, a positive cross pattern (positive anisotropic astigmatism), a saddle-
A negative cross pattern (negative anisotropic astigmatism) occurs in the saddle deflection yoke. This phenomenon is mainly due to the difference in the positions of the deflection centers of the horizontal deflection coil and the vertical deflection coil. Generally, in the saddle toroidal deflection yoke, the position of the saddle coil used for horizontal deflection is changed from the toroidal coil position to the deflection yoke axial direction. It is shifted and considered optimal. This will be described with reference to FIG. When the deflection center of the toroidal coil that generates the vertical magnetic field and the deflection center of the saddle coil that generates the horizontal magnetic field are set to be substantially the same, a convergence error generally called a positive cross pattern is generated as shown in FIG. Occurs. By shifting the deflection center of the horizontal deflection saddle coil to the electron gun side in order to correct such a positive cross pattern, the cross pattern is corrected as shown in FIG. 4 (c). Further, when the horizontal deflection saddle coil is shifted to the electron gun side, a negative cross pattern appears as shown in FIG. 4 (b). Therefore, generally, the cross pattern can be corrected by appropriately assembling the relative positions of the horizontal deflection coil and the vertical deflection coil.

However, such a method can correct the cross pattern only at one point on the diagonal, for example, and at the other points, the fifth pattern can be corrected.
A cross pattern as shown in the figure occurs. Such inversion of the cross pattern between the intermediate portion and the diagonal outermost portion becomes conspicuous especially as the deflection angle and the screen size increase. Therefore, conventionally, a method of reducing the outermost cross pattern by attaching a magnetic plate or the like to the deflection yoke has been adopted, but insufficient characteristics have been obtained.

The inventors previously applied for a system in which the deflection centers of the two sets of deflection coils are displaced from each other, and the horizontal deflection signal and the vertical deflection signal are deflected by different deflection currents that are synchronized with each other. The method of the above-mentioned application is effective, but if the deflection centers of the two deflection coils are displaced to attempt to remove sufficient cross-misconvergence, the displacement of the deflection centers becomes large, and the deflection yoke is limited due to mechanical size constraints. Was found to be difficult to manufacture.

(Problem to be Solved by the Invention) The problem with the above technique is that the deflection center difference between the two deflection coils is particularly large.

An object of the present invention is to solve the above-mentioned problems, and to correct the cross pattern of convergence depending on the deflection amount, one of the sets is dynamically changed to a pincushion or barrel magnetic field. The deflection coils are pincushion magnetic fields, the other sets of deflection coils are barrel magnetic fields, and they are driven by different deflection currents in synchronization with the deflection signals.

[Configuration of the invention]

(Means for Solving the Problems) The present invention relates to a vacuum envelope, a fluorescent screen arranged in the vacuum envelope, and an in-line type electron gun for irradiating three electron beams toward the fluorescent screen. And a horizontal picture deflector for deflecting the electron beam in the horizontal direction and a vertical deflector for deflecting the electron beam in the vertical direction so that the electron beam impinges on a predetermined area of the phosphor screen. At least one of the device and the vertical deflection device is composed of a deflection coil that forms a barrel-shaped magnetic field and a deflection coil that forms a pincushion-shaped magnetic field, and these deflection coils are driven by different deflection currents. By displacing the deflection centers of the magnetic fields formed with each other and changing the magnetic field distribution, the concentration of the three electron beams on the entire phosphor screen can be improved. A color picture tube apparatus according to claim.

(Operation) According to the present invention, it is possible to easily improve the cross pattern by shifting the deflection center of the color picture tube.

 Hereinafter, the operation of the present invention will be described.

First, suppose that the vertical toroidal coil is an A coil,
Two types of horizontal saddle coils, a B coil and a C coil, are used. Assuming that the convergence characteristic of the deflection device in which the A coil and the B coil are combined is shown in FIG. 4A, the relationship between the deflection center of the horizontal deflection coil and the deflection center of the vertical deflection coil is as shown in FIG. 6A. . In such a case, it is preferable that the combination of the above-mentioned three sets of deflection coils has the cross-convergence characteristic shown in FIG.
At this time, for example, when deflecting to P ₁ in FIG. 5, the deflection current of the C coil is made larger than the deflection current of the B coil, and P _{3 in} FIG.
When deflecting to a point, if the deflection current of the B coil is made larger than the deflection current of the C coil, good cross-convergence characteristics can be obtained over the entire surface of the color picture tube as shown in FIG. At this time, if the C coil is formed by the barrel and the B coil is formed by the pincushion magnetic field, the correction effect of the positive cross-miss convergence at the point P ₁ and the negative cross-misconvergence at the point P ₃ becomes large, and the modulation applied to the deflection current is small. Good. In order to obtain such a characteristic, it suffices to supply a current to the horizontal deflection B coil and the C coil at a current ratio according to the deflection amount. That is, a current as shown in FIG. 8 may be supplied. Such a deflection current may be obtained by modulating the output current of the deflection circuit with a vertical deflection current as shown in FIG. Further, the deflection coil used in the present invention can be easily manufactured by using a configuration as shown in FIG. 9 in the case where the vertical deflection coil is a toroidal coil and the horizontal deflection coil is a saddle coil.

In FIG. 9, the deflection device is constituted by a vertical deflection toroidal coil (15) wound around a ferrite core (18) and two sets of horizontal deflection saddle coils (16, 17).

(Example) The example of this invention is demonstrated based on drawing.

FIG. 1 is a diagram showing a preferred embodiment of the present invention. An electron gun (10) is enclosed in a neck portion (9) of the vacuum envelope, and an electron beam (not shown) is emitted toward a fluorescent screen (not shown) in the vacuum envelope.

In the case of the present embodiment, the deflection device is constituted by a saddle-toroidal shape, the vertical deflection coil (15) is preferably constituted by a toroidal coil wound around a ferrite core (18), and the horizontal deflection coil is arranged inside the toroidal coil. It is composed of two sets of wound saddle coils (16, 17) each having a different magnetic field distribution in the axial direction of the tube. The two saddle type coils (16, 17) of the horizontal deflection coil are composed of the first saddle type coil (16) and the second saddle type coil (17), and the first saddle type coil (16) is vertical. When combined with a deflecting toroidal coil (15), it has a positive cross-convergence characteristic, and the first saddle coil is configured to form a pincushion type magnetic field, as shown in FIG. 4 (a). A cross-convergence characteristic is obtained. When the second saddle type coil (17) and the vertical deflection toroidal type coil (15) are combined, it has a negative cross-convergence characteristic and the second saddle type coil forms a barrel type magnetic field. Therefore, the cross-convergence characteristic shown in FIG. 4 (b) is obtained. When three sets of deflection coils, that is, a vertical deflection toroidal coil (15), a horizontal deflection first saddle type coil and a second saddle type coil are combined, a first saddle type coil and a second saddle type coil are combined. When the same deflection current is applied to the die coil, the cross-convergence characteristic shown in FIG. 5 is obtained. Obtaining such cross convergence characteristics is relatively easy. In the case of such a deflection yoke, it is preferable that the first and second saddle-type deflection coils have a characteristic that the pin cushion type magnetic field and the barrel magnetic field are combined so that there is no convergence deviation as a characteristic on the horizontal axis. is there. When operating such a deflecting device, if the current I _C shown in FIG. 8 is applied to the first saddle coil and the current I _B is applied to the second saddle coil,
Good convergence characteristics can be obtained over the entire surface of the color picture tube.

In the present invention, the horizontal deflection magnetic field formed by the first horizontal deflection coil is pincushion type, and the horizontal deflection magnetic field formed by the second horizontal deflection coil is barrel type, so that the horizontal deflection magnetic field flows in each horizontal deflection coil. Since the modulation of the horizontal deflection current in the vertical deflection cycle can be reduced, the modulation can be easily performed. Also,
Since the difference between the deflection centers of the two sets of horizontal deflection coils can be small, it is easy to manufacture the deflection yoke due to the opportunity size limitation.

FIG. 13 shows an example of a deflection circuit using a saturable reactor. In this embodiment, a saturable reactor that is modulated by a vertical deflection current is provided in the middle of two horizontal deflection coils connected in parallel, and the horizontal deflection coil 1 and the horizontal deflection coil 1 are respectively provided according to the vertical deflection amount of the color picture tube. It is configured so that the current characteristics of the horizontal deflection coil 2 can be changed. Further, each saturable reactor is configured to be biased by a permanent magnet, and the cross-convergence characteristic over the entire surface of the color picture tube can be adjusted.

In this embodiment, the saturable reactor is modulated by the vertical deflection current. However, the saturable reactor can be modulated by the leakage magnetic flux of the vertical deflection coil. Various circuits other than this example can be used for the circuit using the saturable reactor.

The two types of currents may be applied from two series of outputs from the deflection circuit, or a saturable reactor or the like may be used to modulate the reactance.

In the present embodiment, the first saddle type coil and the second saddle type coil are over substantially the entire surface of the first saddle type coil in the tube axis direction of the color picture tube, but as shown in FIG. The one saddle-shaped coil or the second saddle-shaped coil may form the deflection magnetic field almost only in one part. Also,
The vertical deflection coil may be a saddle type coil instead of a toroidal type coil.

A second preferred embodiment will be described with reference to FIG. In this embodiment, the horizontal deflection coil and the vertical deflection coil are 3
All of them are saddle type coils. In this embodiment, the vertical deflection coil is composed of two sets of a first saddle type coil (20) and a second saddle type coil (21). First
The saddle-shaped coil (20) and the second saddle-shaped coil have different deflection centers. Here, when the first vertical deflection saddle type (20) coil and the horizontal deflection coil (19) are combined, preferably, the positive cross-convergence characteristic shown in FIG. When the deflection saddle coil (21) and the horizontal deflection coil (19) are combined, the negative convergence characteristic shown in FIG. 4 (b) is exhibited.

Further, although the deflection magnetic field of the present invention changes the deflection center and the magnetic field distribution, the deflection center of the deflection magnetic field is accurately based on the beam trajectory of the color picture tube, but may be defined by the position of the center of gravity of the coil. The position of the maximum value of the deflection magnetic field may be defined, and when the values are different, the deflection center is also different. Therefore, these positions can be substituted in the normal case.

When combined, it is preferable to configure so as to have a negative cross convergence characteristic shown in FIG. 4 (b). When the same deflection current is applied to the first and second vertical deflection saddle coils by combining the first and second vertical deflection saddle coils and the horizontal deflection coil (19), the cross convergence characteristic shown in FIG. It is preferable to have a configuration having

In the case of the present embodiment, it is preferable that the first vertical deflection coil has a barrel type magnetic field and the second vertical deflection coil has a pincushion type magnetic field.

In the case of the present embodiment, it is preferable to apply the deflection current shown in FIG. That is, it is a positive cross pattern,
When the case where the vertical deflection amount is small current I _B to be applied to the first vertical deflection saddle coil (20) is larger than the current I _A applied to the second vertical deflection saddle coil (21), a positive cross Correct the pattern. The result is a negative cross pattern. When the amount of vertical deflection is large, the second vertical deflection saddle coil (21)
The current I _A applied to the first vertical deflection saddle coil (20)
Large next than the current I _B to be applied to, to correct the negative cross pattern. Therefore, good congency characteristics can be obtained over the entire screen.

FIG. 14 shows an example of a deflection circuit used in the present invention, which uses a diode. This embodiment is good for obtaining current characteristics as shown in FIG. In the present embodiment configured to apply a desired current to each of the vertical deflection coil using a non-linear current-voltage characteristic of the diode, the current value of each vertical deflection coil is _{R 1, R 2, R 3} , R _It can be easily deflected by adjusting the value of ₄ .

In the above embodiments, only two sets of coils in which the deflection center difference is changed in the magnetic field distribution are shown, but the effect is reduced even if only the magnetic field distribution is changed, but it can be sufficiently used as a cross-misconvergence correction effect.

〔The invention's effect〕

According to the present invention, an image having a good convergence property can be obtained over the entire screen of a color picture tube, and its industrial utility value is great.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention, FIG. 2 is a sectional view for explaining a conventional color picture tube device, and FIG.
FIG. 4 is a diagram for explaining a deflection magnetic field used in a conventional color picture tube device, FIGS. 4 and 5 are diagrams for explaining cross-convergence characteristics of a conventional color picture tube, and FIG. 6 is FIG. 7 is a diagram showing the deflection magnetic field distribution of the present invention, FIG. 7 is a diagram showing the convergence according to the present invention, FIG. 8 is an explanatory diagram of the current flowing in the embodiment, and FIGS. 9 and 10 are schematic diagrams of the deflection device of the present invention. Sectional view, FIG. 11 shows an embodiment of the present invention,
FIG. 12 is a diagram for explaining the deflection current in the embodiment of FIG.
13 and 14 are deflection circuit diagrams. 1 ... Face plate, 2 ... Phosphor screen 3 ... Shadow mask, 4 ... Mask frame 5 ... Panel pin, 6 ... Spring 7 ... Funnel, 8 ... Deflection yoke 9 ... Neck, 10 ... Electron gun 11 …… Adjustment magnet, 12 …… Aperture 13 …… Electron beam, 14 …… Inner shield 15 …… Toroidal coil 16 …… First horizontal deflection saddle coil 17 …… Second horizontal deflection saddle coil 18 …… …Ferrite core

Claims (1)

(57) [Claims] 1. A vacuum envelope, a fluorescent screen disposed in the vacuum envelope, an in-line electron gun for irradiating three electron beams toward the fluorescent screen, and the electron beam. In a color picture tube device equipped with a horizontal deflecting device for horizontally deflecting an electron beam so as to impinge on a predetermined region of a phosphor screen and a vertical deflecting device for deflecting the electron beam in a vertical direction, at least the horizontal deflecting device or the vertical deflecting device. One is composed of a deflection coil that forms a barrel type magnetic field and a deflection coil that forms a pincushion type magnetic field. By driving these deflection coils with different deflection currents, the deflection center of the magnetic field formed by each coil A color picture tube characterized in that the three electron beams are concentrated on the entire surface of the phosphor screen by shifting the magnetic fields with respect to each other and changing the magnetic field distribution. Location.