JP2002352746A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube which can suppress occurrence of G1-grid emission by suppressing the temperature rise of a first electrode arranged at a position very close to a cathode. SOLUTION: In a receiving tube having an electron gun 7, comprising a cathode K, a heater for heating the cathode, a plurality of electrodes G1 to G4 arranged in order in the electron beam advance direction, an electrode G1 arranged opposedly to the cathode K comprises a disk part 11, having an electron beam passage hole 13 formed on a required thickness plate, a support part 16 in which a cathode insertion through-holes 15 for inserting the cathode are formed in a thicker plate than the disk part 11 and the disk part 11 is fixed, so that the electron beam passage hole 13 is located almost at the center position of the cathode insertion hole 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color picture tube, and more particularly to an improvement in an electron gun.

[0002]

2. Description of the Related Art The electron gun structure of a color picture tube is supported by an insulating support 9 in a funnel neck 5 as shown in FIG.
Fixed. The electron gun assembly includes a cathode K, a heater (not shown) for heating the cathode K, and a first electrode G1 and a second electrode G which are sequentially arranged in the traveling direction of the electron beam.
2, a third electrode G3 and a fourth electrode G4. Among these electrodes, the first electrode G1 is held at the ground potential, the low acceleration voltage is applied to the second electrode G2, the focus voltage is applied to the third electrode G3, and the fourth electrode G4 is applied to the fourth electrode G4. An anode voltage is applied.

Among these electrodes, the first electrode directly related to the present invention is shown in FIG. 6 (a) in front view, (b) in side view, and (c) in cross section. As shown, the support portion 10 and the disk portion 11 welded to each other
It is composed of

The disk portion 11 is made of a thin plate having a thickness t1 of about 0.2 mm, and is provided on an insulating support 9 (refer to FIG. 5) called bead glass at both ends in the vertical and vertical directions. An uneven portion 12 for supporting and fixing is formed, and three electron beam passage holes 13 are formed in a row in a horizontal direction at a central portion in a vertical direction. By embossing the periphery of these electron beam passage holes 13, a bead 14 having an annular concave portion on the front surface and an annular convex portion on the back surface is formed, thereby increasing the rigidity of the disk portion 11 against bending. I have.

On the other hand, the support portion 10 has a thickness t2 of 0.3.
A thin plate having a thickness of about mm is formed as a material, and an uneven portion 12 for supporting and fixing the insulating support 9 is formed in the same manner as the disk portion 11. Further, a portion corresponding to the electron beam passage hole 13 has a cylindrical shape in the direction of the cathode K. A cylindrical projection 18 formed by drawing into a shape is formed, and the inside of the cylindrical projection 18 is a cathode insertion hole 15. Then, the flatness is maintained by welding the disk portion 11 to the front side of the support portion 10.

[0006]

Generally, in terms of quality of an electron gun, unwanted electron emission (G1) from the first electrode G1.
It is desirable that grid emission (referred to as G1GE) does not occur. It is considered that the G1 grid emission is mainly caused by projections caused by burrs, scratches, and the like on the periphery of the electron beam passage hole 13 formed in the disk portion 11. Therefore, as a countermeasure, burrs on the periphery of the electron beam passage hole 13 may be removed to prevent scratches.

On the other hand, the G1 grid emission
There is such a property that the higher the temperature of the electrode G1 is, the more easily it occurs. Therefore, if the temperature is kept low, it is possible to make it difficult to generate G1 grid emission.

However, during operation of the color picture tube, since the cathode is always heated by the heater, the temperature of the first electrode G1 partially surrounding the cathode tends to increase. Further, since the electron gun is disposed in the cylindrical neck of the funnel, the outer diameter of the electron gun is restricted by the diameter of the neck. Therefore, in a cathode ray tube in which the power consumption is reduced by reducing the neck diameter, the outer diameter of the electron gun is also reduced, and the heat capacity is also reduced, so that the temperature of the first electrode is easily increased, and the generation of G1 grid emission is suppressed. It was in a difficult situation.

The present invention has been made in view of the above circumstances, and a color picture tube capable of suppressing the occurrence of G1 grid emission by suppressing a temperature rise of a first electrode disposed opposite to a cathode. The purpose is to provide.

[0010]

It is known that the temperature of the first electrode during the operation of the color picture tube decreases as the heat capacity proportional to the volume increases. The present invention has been made by paying attention to this point.In order to increase the heat capacity by using a thick plate corresponding to the drawing dimension instead of the support portion which was conventionally formed by drawing a thin plate. It was done.

Therefore, the present invention relates to a color picture tube including a cathode, a heater for heating the cathode, and an electron gun including a plurality of electrodes sequentially arranged in a direction in which an electron beam travels. Electrodes to be arranged, a disk portion having an electron beam passage hole formed in a plate having a desired thickness, and a cathode insertion hole for inserting a cathode in a plate having a thickness greater than the disk portion are formed to penetrate, And a holding section to which the disk section is fixed so that the electron beam passage hole is located substantially at the center of the cathode insertion hole.

According to a second aspect of the present invention, in the color picture tube according to the first aspect, the thickness of the holding portion is about 10 times the thickness of the disk portion.

According to a third aspect of the present invention, in the color picture tube according to the first or second aspect, three electron beam passing holes of the disk portion and three cathode insertion holes of the holding portion are formed in a row in the horizontal direction. It is characterized by having been done.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view showing the overall configuration of a color picture tube according to the present invention. The color picture tube has an envelope composed of a panel 1 and a funnel 2 integrally joined to the panel 1. Among them, a stripe or dot emitting blue, green, and red light is provided on the inner surface of the panel 1. A phosphor screen layer (target) 3 made of a three-color phosphor layer is formed, and a shadow mask 4 having an aperture formed on one surface thereof is mounted opposite to the phosphor screen layer 3.

On the other hand, an electron gun 7 for emitting three electron beams 6B, 6G, 6R is provided in the neck 5 of the funnel 2. Then, 3 emitted from the electron gun 7
The electron beams 6B, 6G, and 6R are deflected by horizontal and vertical deflection magnetic fields generated by a deflection yoke 8 mounted on the outside of the funnel 2, and the phosphor screen layer 3 is horizontally shifted via a shadow mask 4. It is formed in a structure that displays a color image by scanning in the vertical direction.

In such a color picture tube, in particular, three electron beams 6B, 6G, 6R arranged in a line composed of a center beam 6G passing through the electron gun 7 on the same horizontal plane and a pair of side beams 6B, 6R on both sides thereof. An in-line type electron gun that emits light, the three electron beams are concentrated at the center of the screen by decentering the positions of the side beam passage holes of the low-voltage side and the high-voltage side electrodes of the main lens portion of the electron gun, and a deflection yoke. 8 is a pincushion type and the vertical deflection magnetic field is a barrel type, and the three electron beams 6B, 6G, 6R arranged in a line are self-concentrated over the entire screen, and a self-convergence type in-line is used. A type color picture tube is constituted.

In the above-described electron gun assembly, as shown in FIG. 2, half of the electrode is shown with the center line as a boundary, and each electrode is supported and fixed on an insulating support 9 called bead glass. The electron gun assembly includes a cathode, an unillustrated heater for heating the cathode, and an electron beam forming unit including a plurality of electrodes sequentially arranged in the electron beam traveling direction, and focuses the electron beam on the phosphor screen layer 3. Has a plurality of lenses including a main lens, and among these electrodes,
The first electrode G1 is held at the ground potential, a low potential, for example, an acceleration voltage of 500 to 800 V is applied to the second electrode G2, a focus voltage of about 5 kV to 10 kV is applied to the third electrode G3, An anode voltage of about 25 kV to 35 kV is applied to the four electrodes G4 and the convergence cup CV.

Of the above-mentioned electrodes, the second to fourth electrodes G2 to G4 and the convergence cup CV are not directly related to the present invention, so that detailed description thereof is omitted, and the first electrode G1 related to the present invention is omitted. Will be described in more detail. 3A and 3B show the configuration of the first electrode according to the present embodiment, in which FIG. 3A is a front view, FIG. 3B is a side view, and FIG. 3C is a cross-sectional view. Here, the first electrode G1
Is composed of a disk portion 11 and a support portion 16 welded to each other.

The disk portion 11 is made of a thin plate having a thickness t1 of about 0.2 mm and is provided on an insulating support 9 (refer to FIG. 2) called bead glass at both ends in the vertical and vertical directions. An uneven portion 12 for supporting and fixing is formed, and three electron beam passage holes 13 are formed in a row in a horizontal direction at a central portion in a vertical direction. By embossing the periphery of these electron beam passage holes 13, a bead 14 having an annular concave portion on the front surface and an annular convex portion on the back surface is formed, thereby increasing the rigidity of the disk portion 11 against bending.

The shape and diameter of the electron beam passage hole 13 formed in the disk portion 11 and the material thickness of the formed portion are important factors in the characteristics of the electron gun, and the thickness is about 0.2 mm. The material thickness of a portion where the electron beam passage hole 13 is formed from the material is secured, and the electron beam passage hole 1 is formed.
Form 3 The disk portion 11 has a material thickness of 0.2 m.
Since it is on the order of m, it is difficult to incorporate this into an electron gun without deformation.

On the other hand, the support portion 16 has a thickness t3 of 2.0
Using a thick plate of about mm as a material,
Irregular portions 17 for supporting and fixing the insulating support 9 at both ends in the vertical and vertical directions are formed, and the axes are substantially aligned with the positions corresponding to the electron beam passage holes 13 respectively. Three cathode insertion holes 15 whose inner diameters are substantially equal to the beads 14 are formed.

The disk portion 11 is welded to the rear end of the support portion 16 in the electron beam traveling direction, whereby the disk portion 11 is firmly fixed, and is incorporated into the electron gun as the first electrode G1 without causing deformation. .

As shown in FIG. 2, the first electrode G1 has the support portion 16 on the cathode K side and the disk portion 11
Is incorporated in the electron gun so as to be positioned on the second electrode G2 side. In this case, the electron beam passage hole 1 of the first electrode G1
The distance between the third electrode G2 and the electron beam passage hole formed in the second electrode G2 is an important requirement in the characteristics of the electron gun, and is several hundred μm
It is about. Further, the cathode K is inserted into the cathode insertion hole 15 of the support part 16 and is fixed so that the interval between the cathode K and the disk part 11 is several tens to several hundreds μm.

Here, when the conventional support portion 10 of the first electrode G1 is compared with the support portion 16 of the present embodiment, the conventional support portion 10 is formed by drawing a material having a thickness of about 0.3 mm. In contrast, the support portion 16 according to the present embodiment has the cathode insertion hole 15 formed in a thick plate having a thickness of about 2.0 mm, while the three cylindrical protrusions 18 are formed. The volume converted to the heat capacity can be greatly increased. Such an increase in heat capacity can keep the temperature of the first electrode low.

FIG. 4 is a diagram plotting the relationship between the heater voltage and the temperature of the first electrode G1 when an electron gun incorporating the conventional support unit 10 and the support unit 16 of this embodiment is operated. is there. Here, the horizontal axis is the heater voltage, the vertical axis is the temperature of the first electrode G1, and the temperature of the first electrode G1 of the present embodiment shown by a broken line compared to the conventional first electrode G1 shown by a solid line. Is clearly lower.

Thus, according to the above embodiment, the volume of the first electrode G1, that is, the heat capacity is increased, whereby the temperature of the first electrode G1 is kept low.
Generation of one grid emission can be suppressed.

In the above-described embodiment, a plate material having a thickness of about 0.2 mm is used as the disk portion 11 and the support portion 1
Although a plate material having a thickness of about 2.0 mm was used for 6, considering the practical neck diameter of the funnel 2, the length of the electron gun assembly, and the mutual interval heater structure of the electron beam passage holes 13, etc. Good results were obtained by setting the ratio of the material thickness of the disk portion 11 to the material thickness of the disk portion 11 in the range of, for example, 8 to 13: 1, and optimally about 10: 1.

[0028]

As is apparent from the above description, according to the present invention, the electrode opposed to the cathode is formed by a plate having a desired thickness and an electron beam passage hole formed in the plate, A cathode insertion hole for inserting a cathode into a plate having a thickness greater than the thickness of the portion is formed so as to penetrate, and a holding portion to which a disk portion is fixed at an end in the traveling direction of the electron beam is provided. In addition, it is possible to provide a color picture tube capable of suppressing the temperature rise and suppressing the generation of G1 grid emission.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an overall configuration of an embodiment of a color picture tube according to the present invention.

FIG. 2 is a cross-sectional view showing a half of a configuration of an electron gun assembly in the embodiment shown in FIG. 1 with a center line as a boundary.

3 is a front view, a side view, and a cross-sectional view showing a configuration of a first electrode constituting the electron gun assembly shown in FIG.

FIG. 4 is a diagram showing a relationship between a heater voltage and a temperature in order to compare the embodiment shown in FIG. 1 with a conventional device.

FIG. 5 is a cross-sectional view showing a half of a configuration of an electron gun assembly mounted on a conventional color picture tube with a center line as a boundary.

FIG. 6 is a front view, a side view, and a cross-sectional view showing a configuration of a first electrode constituting the electron gun assembly shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Panel 2 Funnel 3 Phosphor screen layer 4 Shadow mask 5 Neck 7 Electron gun 8 Deflection yoke 9 Insulating support 11 Disk part 12, 17 Uneven part 13 Electron beam passage hole 14 Bead 15 Cathode insertion hole 16 Support part G1-G4 1st to 4th electrodes

Claims (3)

[Claims] 1. A color picture tube including a cathode, a heater for heating the cathode, and an electron gun including a plurality of electrodes sequentially arranged in a direction in which an electron beam travels, wherein the electrode arranged to face the cathode comprises: A disk portion having an electron beam passage hole formed in a plate having a desired thickness, and a cathode insertion hole for inserting the cathode in a plate having a thickness greater than the disk portion is formed so as to penetrate therethrough; And a holding portion to which the disk portion is fixed at an end such that the electron beam passage hole is located substantially at the center of the color picture tube. 2. The color picture tube according to claim 1, wherein the thickness of said holding portion is about 10 times the thickness of said disk portion. 3. A color image receiving apparatus according to claim 1, wherein three electron beam passing holes of said disk portion and three cathode insertion holes of said holding portion are formed in rows in a horizontal direction. tube.