JP3401839B2 - Color picture tube equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high resolution color picture tube device comprising a color picture tube and a driving means thereof.

[0002]

2. Description of the Related Art The resolution of a picture tube device depends on the size and shape of a beam spot formed on the screen of a phosphor. In order to obtain high resolution, the beam spot should be as small as possible and close to a circle. Is required.
Further, in the color picture tube device, it is important for the three electron beams to concentrate at one point on the phosphor screen surface in terms of resolution and color reproducibility.

In a color picture tube device using an in-line color picture tube, the horizontal deflection magnetic field distribution is distorted in a pincushion shape as shown in FIG. 3, and the vertical deflection magnetic field is distorted in a barrel shape as shown in FIG. By doing 3
The electron beams 1, 2 and 3 are self-converged.

However, if such a self-focusing method is adopted, the cross-sectional shape of the three electron beams 1, 2, 3 is distorted into a non-circular shape as the deflection angle of the electron beam increases, and as shown in FIG. Distortion occurs in the beam spot 5 generated in the peripheral portion of the surface 4. That is, while the beam spot 6 generated in the central portion of the phosphor screen surface 4 is a perfect circle, the beam spot 5 generated in the peripheral portion is in the elliptical high-brightness core portion 5a that is long in the horizontal direction. The low-luminance haze portion 5b that is long in the vertical direction is distorted into a non-circular shape that accompanies it, and high resolution cannot be obtained particularly in the peripheral portion of the phosphor screen surface 4.

The cross-sectional shape distortion of such an electron beam is
This is because the deflection yoke in the self-focusing system gives an inhomogeneous magnetic field as shown by the curves in FIGS. 3 and 4 to the electron beam in the deflection magnetic field. The degree is weakened in the horizontal direction,
In the vertical direction, it is strengthened in reverse.

The decrease in resolution due to such deflection distortion is described in JP-A 61-99249 and JP-A 3-1.
This can be solved by the technique disclosed in Japanese Patent Publication No. 02743.

In FIG. 6 showing this structure, the three cathodes 7a, 7b and 7c arranged in line are the control electrodes 8
The acceleration electrode 9 and the acceleration electrode 9 form a triode, and the first focusing electrode 11 and the second focusing electrode 12 are sequentially arranged between the triode and the final acceleration electrode 10. While a constant DC voltage Vf is applied to the first focusing electrode 11, a DC voltage Vf and a dynamic voltage Vd superimposed on the DC voltage Vf are applied to the second focusing electrode 12. Since the dynamic voltage Vd rises as the deflection angle of the electron beam increases, a quadrupole lens electric field is generated between the first focusing electrode 11 and the second focusing electrode 12. By distorting the cross-sectional shape of the electron beam passing therethrough, the above-mentioned distortion in the deflection magnetic field can be canceled out as a result.

In order to generate the electric field of the quadrupole lens, three electron beam passage holes 11a, 11b, 1 are formed in the end surface of the first focusing electrode 11 on the second focusing electrode 12 side.
1c is formed to be vertically long with its long axis in the vertical direction, and the three electron beam passage holes 12a, 12b, 12c provided on the end surface of the second focusing electrode 12 on the first focusing electrode 11 side are extended horizontally. Form a horizontally long shaft. Va represents the final acceleration voltage (anode voltage).

[0009]

This technique has a remarkable effect and is therefore applied to many kinds of products. In particular, a wide-angle deflection, large-screen aspherical phosphor screen surface (aspect ratio 16: 9, etc.) is used. When applied to a color picture tube device having, the maximum value of the dynamic voltage required becomes very high. For this reason, not only discharge easily occurs in the socket of the color picture tube, but also a high withstand voltage is required for the electronic parts, wiring, etc. in the dynamic voltage generating circuit, which leads to high cost.

The maximum value of the dynamic voltage is such that an electrode structure as shown in Japanese Patent Laid-Open No. 63-893, that is, a non-circular opening is formed in the main lens generating electrode (corresponding to 10 and 12 in FIG. 6). It becomes higher in the ones that have been given. For example, for a color picture tube having a main lens diameter of 7.8 mm, the anode voltage Va is 32 KV and the focusing voltage V is
When f is set to 8.6 KV (focusing voltage ratio 27%),
The maximum value of the required dynamic voltage Vd is about 2 KV. In addition, when the anode voltage Va is set to 32 KV and the focusing voltage Vf is set to 8.6 KV (focusing voltage ratio 27%) for a large screen color picture tube having a main lens diameter of 10.5 mm, the required dynamic voltage is required. The maximum value of Vd is 4K
It reaches V.

Therefore, it is conceivable to reduce the focusing voltage ratio to the large-screen color picture tube to about 20% and suppress the amplitude of the dynamic voltage Vd. However, if the focusing voltage Vf is lowered, the potential difference from the acceleration voltage decreases, so It has a great influence on the electric field distribution of the focus lens. As measures against this, it is necessary to reduce the distance between the accelerating electrode 9 and the focusing electrode 11, reduce the plate thickness of the control electrode 8, or reduce the accelerating voltage. In this case, a foreign substance remains between the electrodes having a narrow gap, which may cause a spark, or the electrodes having a reduced plate thickness may be deformed.

[0012]

According to the present invention, in order to solve the above-mentioned problems, a plurality of focusing electrodes are sequentially arranged between a three-electrode portion including a cathode, a control electrode and an accelerating electrode and a final accelerating electrode. A constant DC voltage V1 is applied to the first focusing electrode adjacent to the three-pole part, and a constant DC voltage V2 and a dynamic voltage superimposed thereon are applied to the second focusing electrode adjacent to the final acceleration electrode. Applied directly to the final accelerating electrode
The dynamic voltage Va is applied, and the dynamic voltage gradually increases with an increase in the deflection angle to strengthen the quadrupole lens electric field generated between the second focusing electrode and the third focusing electrode adjacent thereto, Va A color picture tube device is provided, which is equipped with a bipotential type in- line type electron gun with > V1> V2 and a self-convergence type deflection yoke.

Here, a third focusing electrode to which a constant DC voltage V3 is applied can be arranged between the first focusing electrode and the second focusing electrode (V3 <V2). Also, the third focusing electrode can be connected to the accelerating electrode in the tube.

[0014]

In the present invention, the DC voltage V1 for the first focusing electrode adjacent to the triode is set higher than the DC voltage V2 for the second focusing electrode adjacent to the final accelerating electrode, that is, the prefocus lens. DC voltage V on the side
Since the DC voltage V2 alone can be reduced with almost no reduction of 1, the potential difference from the final acceleration voltage Va is increased, the sensitivity of the focusing action by the dynamic voltage Vd is relatively increased, and the amplitude of the required dynamic voltage is increased. Get smaller. Therefore, the resolution of the large-screen color picture tube device can be increased with almost no influence on the prefocus lens and without causing sparks or electrode deformation due to foreign matter.

[0015]

Embodiments of the present invention will now be described with reference to the drawings.

The in-line type color picture tube device shown in FIG. 1 has three cathodes 7a, 7b, 7 arranged in-line.
c, the control electrode 8 and the accelerating electrode 9 are provided in the three-pole part, and the first focusing electrode 11 adjacent to the accelerating electrode 9 and the second focusing electrode 12 adjacent to the final accelerating electrode 10 are included. As usual.

However, the first focusing electrode 11 and the second focusing electrode 1
A box-shaped third focusing electrode 13 is provided between the third focusing electrode 13 and the second focusing electrode 13, and a constant DC voltage V3 (V3 <V
2) is applied. In the illustrated example, the third focusing electrode 1
Since 3 is connected to the accelerating electrode 9 in the tube, the number of external lead terminals does not increase. In addition, V1 is applied to the first focusing electrode 11.
And a constant DC voltage is applied to the second focusing electrode 12,
A direct current voltage of V2 and a dynamic voltage of Vd superposed on the direct current voltage of V2 are applied to set the relationship of V1> V2. However, the dynamic voltage Vd is 0 V when the deflection angle of the electron beam is 0, and gradually increases as the deflection angle increases.

Third focusing electrode 13 and second focusing electrode 12
As shown in FIG. 2, the non-circular electron beam passage holes 13a, 13b, 13c, such as rectangles or ellipses, whose major axis is perpendicular to the opposite end faces, and rectangular or long axes whose major axis is horizontally oriented, are shown in FIG. Non-circular electron beam passage holes 12a, 12b, 12c such as a circle are arranged inline.

The illustrated control electrode 8 is cup-shaped,
It has three electron beam passage holes 8a, 8b, 8c arranged inline on its end face. The control electrode 8 may be plate-shaped. The accelerating electrode 9 is made of a thick plate-like body and has three electron beam passage holes 9a, 9b, 9c arranged in line. The first focusing electrode 11 is of a box type and has three electron beam passage holes 11a, 11b, 11c arranged in-line on the end surface on the accelerating electrode 9 side, and the end surface on the third focusing electrode 13 side is also in-line. It has three electron beam passage holes 11d, 11e, and 11f arranged. On the end face of the third focusing electrode 13 on the first focusing electrode 11 side, three electron beam passage holes 13d, 13e, 13f arranged inline are also arranged. The third focusing electrode 13 can be formed of a plate-shaped body.

The second focusing electrode 12 is of a box type and has one large oblong opening 12d having a major axis in the horizontal direction on the end surface on the side of the final accelerating electrode 10, and an electric field near the opening. The correction electrode plate 12e is incorporated. The final accelerating electrode 10 to which a constant anode voltage of Va is applied is also of a box type.
On the end face on the focusing electrode 12 side, there is one large-diameter oval opening 10d having a major axis in the horizontal direction, and an electric field correction electrode plate 10e is built in the vicinity of this opening 10d. 14a, 14
Reference numerals b and 14c represent a prefocus lens electric field, and 15 represents a main lens electric field.

A constant bias voltage of about 160 V and a modulation signal corresponding to image information are applied to the cathodes 7a, 7b, 7c. The control electrode 8 is kept at the ground potential, and a constant voltage of about 600 V is applied to the acceleration electrode 9 and the third focusing electrode 13. About 9 KV, which corresponds to about 28% of the voltage applied to the final acceleration electrode 10, is applied to the first focusing electrode 11.
Constant DC direct pressure V1 is applied. In addition, the anode voltage Va applied to the final acceleration electrode 10 is applied to the second focusing electrode 12.
Constant DC voltage V of about 6.5 KV corresponding to about 20% of
2 and the dynamic voltage Vf superimposed on this are applied. Then, an anode voltage of about 32 KV is applied to the final acceleration electrode 4.

With such a configuration, the second focusing electrode 1
Since the DC voltage V2 applied to 2 becomes 70 to 80% of the voltage Va applied to the final acceleration electrode 10, the sensitivity of the focusing action by the dynamic voltage Vd is relatively increased.
Therefore, the maximum value of the dynamic voltage Vd is, as an example, a 36-inch 110-degree deflection type color picture tube (glass tube neck diameter 32.5 mm, screen aspect ratio 1).
In 6: 9), it can be set to a practical value of about 2 KV.

Furthermore, since a DC voltage V1 of about 9 KV is applied to the first focusing electrode, it is necessary to narrow the mutual distance between the accelerating electrode 9 and the first focusing electrode 11 or reduce the plate thickness of the control electrode 8. Without prefocus lens electric field 14a, 14
b and 14c can be optimally maintained. Further, since sparks and electrode deformation do not occur, it is possible to provide a high-resolution color picture tube device without lowering reliability.

[0024]

As described above, according to the present invention, even for a color picture tube device having a large screen, it is possible to obtain a high resolution over the entire phosphor scoop surface with a relatively low dynamic voltage. It is possible to provide a highly reliable color picture tube device, which does not require such a circuit element and has no fear of electric discharge inside and outside the tube. Further, the performance can be further enhanced by adding the third focusing electrode, and by connecting the third focusing electrode to the accelerating electrode in the tube, it is not necessary to increase the extra-tube lead terminal.

[Brief description of drawings]

FIG. 1 is a sectional view mainly showing an electrode array of a color picture tube device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of a color picture tube device according to an embodiment of the present invention.

FIG. 3 Magnetic field distribution diagram of horizontal deflection magnetic field for self-focusing

FIG. 4 Magnetic field distribution diagram of vertical deflection magnetic field for self-focusing

FIG. 5 is a diagram schematically showing the shape of a beam spot generated on the phosphor screen surface.

FIG. 6 is a cross-sectional view mainly showing an electrode array of a conventional color picture tube device.

[Explanation of symbols]

7a, 7b, 7c cathode 8 control electrodes 9 Accelerating electrode 10 Final acceleration electrode 11 First focusing electrode 12 Second focusing electrode 13 Third Focusing Electrode

Continuation of the front page (56) References JP-A-4-245145 (JP, A) JP-A-63-181245 (JP, A) JP-A-4-66753 (JP, U) (58) Fields investigated (Int .Cl. ⁷ , DB name) H01J 29/48-29/50

Claims (3)

(57) [Claims] 1. A plurality of focusing electrodes are sequentially arranged between a three-electrode portion including a cathode, a control electrode and an accelerating electrode and a final accelerating electrode, and a constant direct current is applied to a first focusing electrode adjacent to the three-electrode portion. The voltage V1 is applied, a constant DC voltage V2 and a dynamic voltage superimposed on the constant DC voltage V2 are applied to the second focusing electrode adjacent to the final acceleration electrode, and the DC voltage V2 is applied to the final acceleration electrode.
a is applied, the dynamic voltage gradually increases with an increase in the deflection angle, and the second focusing electrode and the first focusing electrode adjacent to the second focusing electrode .
Strengthens the quadrupole lens electric field generated between the three focusing electrodes,
A color picture tube device comprising a bipotential type in -line type electron gun with Va> V1> V2 and a self-convergence deflection yoke. 2. An arrangement is provided between the first focusing electrode and the second focusing electrode.
A constant DC voltage V3 is applied to the third focusing electrode provided.
2. The color picture tube device according to claim 1, wherein V3 <V2. 3. The color picture tube device according to claim 2, wherein the third focusing electrode is connected to the accelerating electrode of the triode portion in the tube.