JP2001185053A - Color cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome problems such as generations of withstand voltage lowering, leak current, in consequence deterioration of convergence and convergence drift, as getter particles and positive ions of residual gas in a tube, in power save type of color cathode ray tube including a small diameter neck having a deflection yoke disposed at periphery, and a large diameter neck within which electron gun is housed. SOLUTION: A distance between an end of the large diameter neck 102 and an end of the small diameter neck 101 of final acceleration electrode 107 is not more than 2.5 mm, and the neck 102 positions at an inclined boundary between the small diameter neck 101 and the large diameter neck 102. Further, when using the neck 102 positioned at an inclined boundary between the small diameter neck 101 and the larger diameter neck 102 as reference, there is not less than 8 mm a protruded amount to a small diameter neck 101 of a shield cap 108. Also a clearance between the small diameter neck 101 and the shield cap 108 is not more than 1.3 mm, at one side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube and, more particularly, to the outer diameter of a neck at a position where a deflection yoke is arranged.
The present invention relates to a color CRT electron gun having a diameter smaller than the outer diameter of a neck for accommodating the electron gun.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view of a general color cathode ray tube (first conventional example) 400. As shown in FIG. Color CRT 4
00 is a panel 402 constituting the front part of the valve 401.
A fluorescent film 403 formed on the inner surface of the
4 are sequentially arranged, an electron beam 407 from an electron gun 406 of a neck 405 is deflected by a deflection yoke 408, and the fluorescent film 403 is scanned via a shadow mask 404 to display an image. . In addition,
The neck 405 has the same outer diameter from near the welded portion to the funnel 409 to the electron gun 406 side.

As shown in FIG. 5, an electron gun 406 comprises a cylindrical electrode such as a cathode (not shown), a control electrode 501, an accelerating electrode 502, a converging electrode 503, and a final accelerating electrode 504. Are stacked with high precision by an assembling jig, and are fixed to a pair of insulating supports 505 by implanting respective ends thereof. A plurality of bulb spacers 507 are fixed on the side of the fluorescent film 403 of the shield cup 506 attached to the final acceleration electrode 504, and the leading end thereof is a graphite film 508 electrically connected to an anode electrode (not shown). Is in contact with

[0004] The valve spacer 507 is provided with an electron gun 4.
The axis of the axis 06 and the axis of the neck 405 are combined with each other, and the anode voltage is supplied to the final acceleration electrode 504. The role of the graphite film 50 is that the portion of each bulb spacer 507 bulging outward is formed on the inner wall of the neck 405.
8 is achieved.

[0005] In recent years, in particular, color CRTs for displays have been required to have higher market requirements in terms of function and quality, such as larger size, thinner, higher brightness, and higher resolution. These market demands are accompanied by difficulties, particularly because they are improvements with reduced power consumption. This power consumption is
It is mainly determined by the deflection power, and power saving can be realized by suppressing the deflection power.

The deflection power is mainly governed by the horizontal deflection power. To reduce the horizontal deflection power, one of the horizontal deflection frequency, the inner diameter of the envelope of the deflection coil, the acceleration voltage, and the horizontal deflection angle is reduced, or the horizontal deflection power is reduced. It is necessary to increase the axial dimension of the deflection coil.

The applicant has already invented a color cathode ray tube in which the deflection power is reduced by improving the deflection sensitivity,
It was disclosed in Japanese Patent Application Laid-Open No. 11-111200 (second conventional example). FIG. 6 is a cross-sectional view of the power-saving color CRT 600 disclosed in the above publication. The feature is that the neck 601 of the color cathode ray tube 600 is composed of a small diameter neck 601A around which a deflection yoke 602 is disposed and a large diameter neck 601B for accommodating an electron gun therein.
(2) Energy saving by reducing the inner diameter of the envelope surface.
With this configuration, power saving of 30 to 50% is achieved as compared with the general color cathode ray tube 400 of the first conventional example.

FIG. 7 is a partial sectional view of a neck 601 of a color CRT 600 according to a second conventional example. In FIG. 7, 7
01 is a small diameter neck, 702 is a large diameter neck, 703 is an insulating support, 704 is a control electrode, 705 is an acceleration electrode, 706
Is a focusing electrode, 707 is a final acceleration electrode, 708 is a shield cup, 709 is a valve spacer, and 710 is a graphite film. As shown in FIG. 7, the distance between the end on the large diameter neck 702 side of the boundary inclined portion between the small diameter neck 701 and the large diameter neck 702 and the end on the small diameter neck 701 side of the final acceleration electrode 707 is 2.8 mm. Further, the amount of protrusion of the shield cup 708 toward the small-diameter neck 701 with respect to the end of the large-diameter neck 702 at the boundary inclined portion between the small-diameter neck 701 and the large-diameter neck 702 is 7.2 mm. In addition, small diameter neck 7
01 and the shield cup 708 are on one side.
35 mm.

[0009]

As shown in FIG. 7, in the color CRT 600 of the second conventional example, the diameter of the shield cup 708 is proportionally adjusted by adjusting the diameter of the conventional electron gun 406 to the small diameter neck 701 as shown in FIG. Because of the small structure, the gap between the small diameter neck 701 and the shield cup 708 is large, and the small diameter neck 701 and the final acceleration electrode 70
7 are apart from each other, causing the following problem.

First, in the manufacturing process of the color cathode ray tube 600, a barium getter is vapor-deposited on the inner surface of the glass bulb. The getter particles pass through the gap between the small diameter neck 701 and the shield cup 708 and reach the electron gun. It easily adheres to the support 703. As a result, the insulation resistance between the electrodes is reduced, the withstand voltage is reduced, and a leak current is generated. As a result, the convergence may be deteriorated.

Second, during operation of the color CRT 600, when a high voltage is applied to the electron gun, cations of residual gas in the tube generated by collision with the electron beam are scattered from the panel side to the electron gun side. But this is the shield cup 70
8 and scattered on the inner wall of the electron gun and the large-diameter neck 702, affecting the electric field of the electron lens formed between the electrodes of the electron gun, causing a deviation in the traveling direction of the electron beam, This could cause a so-called charge convergence drift.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a power saving color CRT having a small diameter neck around which a deflection yoke is disposed and a large diameter neck for accommodating an electron gun therein. The purpose is to clarify the appropriate dimensional relationship of the accelerating electrode.

[0013] This solves the problems of convergence deterioration and convergence drift, which have been problems of the power-saving color CRT.
An epoch-making power-saving color cathode ray tube capable of saving power by 30 to 50% has been put to practical use.

[0014]

In order to achieve the above object, a color cathode ray tube according to the present invention has a small diameter neck around which a deflection yoke is disposed and a large diameter neck inside which accommodates an electron gun. The neck, the shield cup and the final accelerating electrode have the following dimensional relationship.

That is, according to the first aspect of the present invention, there is provided a small-diameter neck having a deflection yoke disposed therearound and a large-diameter neck accommodating therein at least an electrode portion of an electron gun having a shield cup and a final accelerating electrode. In a color cathode ray tube having the following, a distance between an end of the small-diameter neck and the large-diameter neck on the large-diameter neck side of a boundary inclined portion and an end of the final acceleration electrode of the electron gun on the small-diameter neck side is 2.5.
mm or less.

According to a second aspect of the present invention, there is provided a small-diameter neck having a deflection yoke disposed therearound and a large-diameter neck accommodating therein at least an electrode portion of an electron gun having a shield cup and a final accelerating electrode. In the color cathode ray tube having the following, the protrusion amount of the shield cup toward the small diameter neck side is 8 m with reference to the large diameter neck side end of the boundary inclined portion between the small diameter neck and the large diameter neck.
m or more.

According to a third aspect of the present invention, there is provided a small-diameter neck around which a deflection yoke is disposed, and a large-diameter neck for accommodating therein an electrode portion of an electron gun having at least a shield cup and a final accelerating electrode. Wherein the clearance between the small diameter neck and the shield cup is 1.3 mm or less on one side.

[0018]

FIG. 1 is a sectional view showing a neck portion of a color cathode ray tube according to a first embodiment of the present invention. FIG.
, 101 is a small diameter neck, 102 is a large diameter neck,
103 is an insulating support, 104 is a control electrode, 105 is an accelerating electrode, 106 is a focusing electrode, 107 is a final accelerating electrode, 10
8 is a shield cup, 109 is a valve spacer, 11
0 is a graphite film.

As shown in FIG. 1, the distance between the end on the large diameter neck 102 side of the inclined portion of the boundary between the small diameter neck 101 and the large diameter neck 102 and the end of the final acceleration electrode 107 on the small diameter neck 101 side is 0.7 mm. It is. (Conventionally, it was 2.8 mm as shown in FIG. 7.) Thus, the end on the large-diameter neck 102 side of the inclined portion between the small-diameter neck 101 and the large-diameter neck 102 and the small-diameter neck 101 of the final acceleration electrode 107. By reducing the distance from the side end, getter particles and residual gas cations are less likely to pass therethrough and less likely to reach each electrode. As a result, the occurrence of convergence deterioration and convergence drift is suppressed. In order to obtain this effect, the distance between the end on the large diameter neck 102 side of the boundary inclined portion between the small diameter neck 101 and the large diameter neck 102 and the end of the final acceleration electrode 107 on the small diameter neck 101 side is 2.5 mm or less. It is necessary to be.

FIG. 2 is a sectional view showing a neck portion of a color CRT according to a second embodiment of the present invention. In FIG. 2, 201 is a small diameter neck, 202 is a large diameter neck, 203
Is an insulating support, 204 is a control electrode, 205 is an accelerating electrode,
206 is a focusing electrode, 207 is a final acceleration electrode, 208 is a shield cup, 209 is a valve spacer, and 210 is a graphite film.

As shown in FIG. 2, the small-diameter neck 20 of the shield cup 208 is referenced to the large-diameter neck 202 side end of the boundary slope between the small-diameter neck 201 and the large-diameter neck 202.
The protrusion amount to one side is 14.3 mm. (Conventionally, it was 7.2 mm as shown in FIG. 7.) By thus increasing the amount of protrusion of the shield cup 208 toward the small-diameter neck 201 side, getter particles and residual gas cations were removed from the shield cup 208 by the shield cup 208. It becomes difficult to pass through the gap between the small diameter necks 201 and it is difficult to reach each electrode. As a result, the occurrence of convergence deterioration and convergence drift is suppressed. In order to obtain this effect, the amount of protrusion of the shield cup 208 toward the small-diameter neck 201 needs to be 8 mm or more.

FIG. 3 is a sectional view showing a neck portion of a color CRT according to a third embodiment of the present invention. In FIG. 3, reference numeral 301 denotes a small-diameter neck, 302 denotes a large-diameter neck, 303
Is an insulating support, 304 is a control electrode, 305 is an acceleration electrode,
306 is a focusing electrode, 307 is a final accelerating electrode, 308 is a shield cup, 309 is a valve spacer, and 310 is a graphite film.

As shown in FIG. 3, the clearance between the small diameter neck 301 and the shield cup 308 is 1 mm on one side. (Conventionally, it was 1.35 mm as shown in FIG. 7.) Thus, the small diameter neck 301 and the shield cup 3
By making the clearance of 08 small, getter particles and residual gas cations are less likely to pass therethrough and less likely to reach each electrode. As a result, the occurrence of convergence deterioration and convergence drift is suppressed.
In order to obtain this effect, the clearance between the small diameter neck 301 and the shield cup 308 needs to be 1.3 mm or less.

In the first to third embodiments, the distance between the large-diameter neck end of the boundary inclined portion between the small-diameter neck and the large-diameter neck and the small-diameter neck end of the final accelerating electrode of the electron gun is determined. The effects of shrinking, increasing the amount of the shield cup protruding toward the small-diameter neck, and reducing the clearance between the small-diameter neck and the shield cup have been implemented independently, but higher effects can be obtained by combining two or more of these. Of course it is possible.

[0025]

As described above, the color cathode ray tube of the present invention comprises a neck and a shield of a power saving type color cathode ray tube having a small diameter neck around which a deflection yoke is disposed and a large diameter neck for accommodating an electron gun inside. By properly setting the dimensional relationship between the cup and the final accelerating electrode,
Leakage current generation, convergence deterioration, convergence drift, etc. are solved, and 30-50
% Of revolutionary power-saving color cathode-ray tubes have been put to practical use.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a neck of a color CRT according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a neck of a color CRT according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a neck of a color CRT according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of a first conventional color cathode ray tube.

FIG. 5 is a partial cross-sectional view of a neck of a color CRT according to a first conventional example.

FIG. 6 is a cross-sectional view of a color CRT of a second conventional example.

FIG. 7 is a partial cross-sectional view of a neck of a color CRT according to a second conventional example.

[Explanation of symbols]

101, 201, 301, 601A, 701 Small diameter neck 102, 202, 302, 601B, 702 Large diameter neck 103, 203, 303, 505, 703 Insulating support 104, 204, 304, 501, 704 Control electrode 105, 205, 305, 502, 705 Accelerating electrodes 106, 206, 306, 503, 706 Focusing electrodes 107, 207, 307, 504, 707 Final accelerating electrodes 108, 208, 308, 506, 708 Shield cups 109, 209, 309, 507, 709 Valve spacer 110, 210, 310, 508, 710 Graphite film 400, 600 Color cathode ray tube 401 Valve 402 Panel 403 Fluorescent film 404 Shadow mask 405, 601 Neck 406 Electron gun 407 Electron beam 408, 602 Deflected yaw K 409 Funnel

Claims (3)

[Claims] 1. A color cathode ray tube having a small-diameter neck around which a deflection yoke is disposed and a large-diameter neck accommodating therein an electrode portion of an electron gun having at least a shield cup and a final accelerating electrode. A distance between the end of the large-diameter neck of the boundary inclined portion of the large-diameter neck and the end of the final acceleration electrode of the electron gun on the small-diameter neck is 2.5 mm or less. . 2. A color cathode-ray tube having a small-diameter neck around which a deflection yoke is disposed and a large-diameter neck accommodating therein at least an electrode portion of an electron gun having a shield cup and a final accelerating electrode. A color cathode-ray tube, wherein an amount of protrusion of the shield cup toward the small-diameter neck side is 8 mm or more with reference to an end of the large-diameter neck on the large-diameter neck side. 3. A color cathode-ray tube having a small-diameter neck around which a deflection yoke is arranged and a large-diameter neck containing therein at least an electrode portion of an electron gun having a shield cup and a final accelerating electrode. And a clearance between the shield cup and the one side is 1.3 mm or less on one side.