JP2001266774A - Glass funnel for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid color dislocation and shade in a cathode-ray tube, using a glass funnel having plural yoke portions and neck glasses, resulting from the inclination of the center axes of the neck glasses with the deformation of a body during evacuation into a high vacuum state. SOLUTION: Two neck glasses 3, located symmetrically at both sides of a tube axis A are welded to the yoke portions in the state of being inclined beforehand, so that the center axis Z of each neck glass is parallel to the tube axis, when they are held at a high vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass funnel for a cathode ray tube mainly used for receiving television broadcasts.

[0002]

2. Description of the Related Art In recent years, various studies have been made to reduce the length of the depth as a display device of a cathode ray tube and to meet a demand for high resolution accompanying an increase in size of a screen, in comparison with a display device other than a cathode ray tube. I have. In order to increase the resolution of the cathode ray tube, it is necessary to reduce the electron beam spot diameter on the screen surface, but as the size increases, the distance between the electron gun and the screen surface increases, so the magnification of the electron lens increases. It becomes too large, and the electron beam spot diameter cannot be reduced. If the distance between the electron gun and the screen can be shortened, this will directly lead to higher resolution, so shortening the depth of the cathode ray tube has a simple external meaning,
This is an important development issue from the viewpoint of high resolution.

As a method of shortening the depth, a method using a plurality of electron guns and a deflection mechanism as shown in FIG. 5 has been proposed (for example, Japanese Patent Laid-Open No. 63-164149). In this method, one screen is divided into a plurality of areas, and a depth is reduced by using a pair of electron guns and a deflection mechanism for each of the reduced areas. That is, the glass funnel 1 is provided with a pair of yoke portions 4 on the body portion 5.
And a neck glass 3, that is, two yoke portions 4 and two neck glasses 3 (hereinafter, abbreviated as two yoke portions and a neck glass, the same applies hereinafter), and a tube axis A passing through the center of the screen and perpendicular to the screen. Are provided symmetrically on both sides, and one image is displayed on a screen using two electron guns mounted on each neck glass 3.

Accordingly, in the glass funnel 1, the central axis Z of each neck glass 3 does not coincide with the tube axis A, and has a certain amount of deviation from the tube axis A. When the cathode ray tube is manufactured by combining the glass funnel 1 with the panel section 2, the inside becomes a high vacuum state, so that the glass funnel 1 is deformed by a load having a pressure difference of 1 atm between the inside and the outside.
This deformation is particularly large in the body of the glass funnel 1.

Due to the deformation of the body portion 5, the neck glass 3 is deformed from a thick solid line indicating an open state to the atmosphere to a virtual line indicating that the inside is in a high vacuum state. For this reason, before the operation of maintaining the inside of the cathode ray tube at a high vacuum, that is, in the state of being opened to the atmosphere, the neck glass 3
Is welded to the yoke part 4 so that the central axis Z of the neck glass 3 and the tube axis A are parallel to each other, but the central axis Z of each neck glass 3 changes to L after the subsequent evacuation process. Then, an inclination occurs with respect to the tube axis A. Θ in the figure indicates the inclination angle at this time.

[0006] Such a relative change with respect to the tube axis A between the open-to-atmosphere state and the high-vacuum state occurs not only at the center axis Z of the neck glass but also at the center of the yoke although not shown. are doing. However, the deviation of the electron beam irradiation position from the electron gun on the screen is considered to be most affected by the inclination of the central axis of the neck glass, and thus the inclination of the central axis of the neck glass is particularly problematic. .

Incidentally, in a so-called single yoke glass funnel comprising one yoke portion and a neck glass, the center axis of the neck glass coincides with the tube axis and is substantially the same. Since it occurs symmetrically with respect to the central axis and the central axis of the neck glass does not substantially tilt before and after the load, there is no problem because it does not appear. Therefore, even with a glass funnel having a plurality of yoke portions and a neck glass, the neck glass welded to the yoke portion located on the tube axis is hardly affected. Are those other than the neck glass located on the tube axis.

[0008]

The glass funnel for a cathode ray tube having a plurality of yoke portions and a neck glass is a unique problem that is not present in a normal single yoke glass funnel. Then, the central axis of each neck glass changes and tilts with respect to the tube axis of the cathode ray tube before and after the operation of evacuating the inside to a high vacuum state. The inclination of the center axis of the neck glass causes the electron gun to shift the original position where the electron beam should be irradiated toward the screen, so that the positional relationship between the irradiation centers of the individual electron beams with respect to the phosphor screen is inconsistent. This causes problems such as color misregistration and color unevenness, and thus is a major problem.

An object of the present invention is to provide a glass funnel for a cathode ray tube having a plurality of yoke portions and a neck glass for solving such a phenomenon as color shift and color unevenness.

[0010]

According to the present invention, there is provided a body having a substantially rectangular opening end, a plurality of yokes for mounting a deflection coil, and an electron gun which is welded to the yoke to store an electron gun. A glass funnel for a cathode ray tube, wherein the body portion forms a space between the opening end and the yoke portion, and the central axis Z of each neck glass is
The neck glass positioned on both sides of the tube axis A so as to be parallel to the tube axis A extending perpendicularly to the screen from the center of the screen due to high vacuum at the time of manufacturing a cathode ray tube using the glass funnel. Are welded to the yoke portion in a state of being inclined outwardly in advance with respect to the tube axis A in a state of being opened to the atmosphere, thereby providing a glass funnel for a cathode ray tube.

[0011]

Next, a glass funnel according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. 1 is a front view of the glass funnel, FIG. 2 is a plan view thereof, and FIG. 3 is an enlarged sectional view of the left half of FIG. The glass funnel 1 is formed on a body 5 as shown in FIG.
It has two yoke portions 4, and a neck glass 3 is welded to each end of the yoke portions. When welding the neck glass 3 to the yoke portion, the center of the yoke portion 4 and the center axis Z of the neck glass 3 are made to coincide with each other.
Reference numeral 7 in FIG. 3 denotes this welded portion.

The body portion 5 has a substantially rectangular opening end portion 6 for sealing with the panel portion 2 at one end, and is a hollow body formed between the yoke portion and the opening end portion. is there.
The shape can be determined as appropriate based on the design specifications of the glass funnel, but usually has a funnel shape.

The yoke part 4 is usually formed symmetrically on both sides of the tube axis A when the body part 5 is formed. Here, the tube axis A is a virtual axis extending perpendicularly to the screen from the center of the screen of the cathode ray tube when the cathode ray tube is manufactured using the above-mentioned glass funnel 1 and the panel section 2, and the design of the cathode ray tube and the glass Functions as a reference axis for various dimensional specifications of the funnel or panel. In an ideal glass funnel, the tube axis A passes through the intersection of the short axis Y and the long axis X of the rectangular opening end 6 as shown in FIG. Therefore,
The two yoke portions 4 are formed on both sides of the tube axis A on the long axis X at predetermined distances from the tube axis A, respectively, and are symmetric with respect to the short axis Y.

According to the present invention, when the neck glass 3 is welded to the yoke portion 4, the center axis Z of the neck glass 3 is not parallel to the tube axis A as in the past, but is inclined by a predetermined angle. It is characterized by. Next, this will be specifically described with reference to FIGS.

The neck glass 3 is welded to the yoke portion with the center of the yoke portion 4 and the center axis Z ₁ of the neck glass 3 substantially aligned as described above. At this time, the glass funnel 1 of the present invention is obtained by inclining the center axis Z ₁ with respect to the tube axis A by θ in a direction in which the tip portion moves away from the tube axis A. The neck glass 3 shown by a solid line in FIG.
It is obtained by welding by inclining a central axis Z ₁ employment. On the other hand, a virtual line indicates a high vacuum state when a cathode ray tube is formed using this glass funnel. It can be seen that, due to the deformation of the body part 5 due to the decompression, the neck glass 3 changes so that the inclination is corrected. L ₁ is the central axis of the neck glass 3 after this deformation, which is aimed to be parallel to the tube axis A. Therefore, if L ₁ is as desired and parallel to the tube axis A, then θ will be the desired angle of inclination of center axis Z ₁ with respect to L ₁ .

In the actual glass funnel 1, θ is determined depending on the amount of deformation of the body portion 5 in a high vacuum state. Since the amount of this deformation varies depending on the shape and thickness of the glass funnel, θ cannot be specified, but it is usually 0.02 to 0.02.
Select in the range of 0.2 degrees. As an effective method for determining θ, the amount of deformation of the body portion can be approximately obtained by structural analysis using a computer, for example. further,
The glass funnel in which the central axis Z is welded in parallel with the tube axis A is actually placed in the same high vacuum state as the cathode ray tube, and it can be obtained by back calculation from the inclination angle of the central axis Z generated at that time. In FIG. 1, the pair of neck glasses 3 are completely symmetrical and have the same form, so that the inclination angles θ of both neck glasses 3 may be the same.

As shown in FIG. 1, the two neck glasses 3 welded in this manner have a front end part which is open outward from the welded part and has a widening. This is used for each neck glass 3
The following description will be made based on the center axes Z ₁ and Z ₂ . That is, assuming that the distance between the central axes Z ₁ and Z _{2 at} the tip of the neck glass is D ₁ , and the distance at or near the welded portion 7 (see FIG. 3) of each neck glass 3 is D ₂ , D ₁ > D ₂ It has become. And the central axis Z ₁ ,
Since Z ₂ passes through the center of each neck glass 3, these D ₁ and D ₂ correspond to the distances between the centers of the tips of both neck glasses 3 and the welded portions. Therefore, it can be easily obtained industrially.

FIG. 4 shows another embodiment of the present invention. In this example, three yoke portions 4 and a neck glass 3 are attached to a body portion 5.
The glass funnel provided, three single yoke portion and the neck glass 3 ₀ of the is located in the tube axis A, on both sides the other two yoke portions and the neck glass 3 _1, 3 ₂ similarly to FIG. 1 Is provided. The neck glass 3 on the tube axis A
_{If the value} is ₀ , even if the body 5 is deformed in a high vacuum state as described above, the center axis thereof is not substantially changed, so that it does not affect the color shift or color unevenness of the cathode ray tube. Therefore, it is sufficient to incline only the neck glasses 3 ₁ and 3 ₂ located on both sides of the tube axis A with respect to the tube axis A in the state of being opened to the atmosphere in advance.

The yoke portion 4 is usually formed integrally with the body portion, but may be provided on the body portion by post-processing by means of, for example, bonding. The number of the yoke and the neck glass is usually 2
Or 3, most commonly the two shown in FIG. However, the present invention is also applicable to a glass funnel provided with a plurality of yoke portions and a neck glass. For example, in the case of four, two are provided side by side on the both sides of the tube axis A (both sides of the short axis Y in FIG. 2), and are applied respectively to two neck glasses located symmetrically or almost symmetrically with respect to the tube axis A. I just need.

In the present invention, the face of the panel portion may be either flat or curved, but on the screen surface flattened with a large radius of curvature, the pipe axis A and the center of the plurality of neck glasses are evacuated after evacuation. Since the parallelism with the axis Z is more strongly required, it is particularly effective for a glass funnel used in combination with a panel having a flat face surface.

[0021]

Although the conventional single-yoke cathode ray tube did not become apparent, in a cathode ray tube comprising a plurality of yoke portions and a neck glass, before and after an operation of evacuating the inside to a high vacuum state, the individual neck glass was not removed. Since the relative axis inclination between the central axis and the tube axis of the cathode ray tube changes, problems such as color shift and color unevenness on the phosphor screen have been caused.

In the present invention, since the center axis of the neck glass is inclined with respect to the tube axis in advance in the open state to the atmosphere, when such a glass funnel is used to manufacture a cathode ray tube, the inclination is reduced to a high vacuum. And the central axis of the neck glass can be made parallel to each other. As a result, problems such as color shift and color unevenness on the screen can be eliminated or reduced.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The glass funnel of this embodiment has two yoke portions and a neck glass as shown in FIG. Also,
The panel portion to be joined to the glass funnel is a 36-inch flat face CRT glass panel having an effective screen with a screen aspect ratio of 16: 9 and a diagonal diameter of 86 cm. Before welding and sealing the neck glass to the yoke part of the glass funnel, a structural analysis was performed using a computer in advance, and the displacement of each part under a load of 1 atm between the internal and external pressures was obtained, and the central axis of the neck glass fell. The amount was calculated.

Next, a substantially rectangular opening end which is polished and flattened is taken as a reference plane, and a neck glass is placed in a yoke portion with respect to a normal line thereof by about 0.0.
The seal was welded at an angle of 5 degrees in the direction defined in FIG.
At this time, since the above-mentioned reference plane is perpendicular to the tube axis, the central axis of each neck glass is sealed by being inclined by the same angle with respect to the tube axis. As a result, when the glass funnel and the panel glass are joined to form a vacuum envelope, and the inside of the vacuum funnel is kept in a high vacuum state, the central axes of the two neck glasses are respectively set with respect to the tube axes. It was confirmed that they were kept parallel.

[0025]

According to the present invention, in a glass funnel for a cathode ray tube having a plurality of yokes and a neck glass, when welding the neck glasses, the center axis of each neck glass is provided on the panel glass when the atmosphere is open to the atmosphere. When the glass bulb is evacuated to a high vacuum, the tube axis and each of the neck glass are evacuated to the tube axis perpendicular to the screen passing through the center of the phosphor screen. Can be kept parallel to each other. This eliminates the displacement of the center position of the electron beam irradiation on the phosphor screen, and can solve the problems of color displacement and color unevenness of the phosphor.

[Brief description of the drawings]

FIG. 1 is a front view of a glass funnel according to a preferred embodiment of the present invention.

FIG. 2 is a plan view of the glass funnel of FIG. 1;

FIG. 3 is an enlarged sectional view of a left half of the glass funnel of FIG. 1;

FIG. 4 is a front view of a glass funnel according to another embodiment of the present invention.

FIG. 5 is a front view of a conventional glass funnel.

[Explanation of symbols]

 1: Glass part 2: Glass funnel 3: Neck glass 4: Yoke part 5: Body part 6: Open end 7: Welded part

Claims (2)

[Claims] A body portion having a substantially rectangular opening end, a plurality of yoke portions for mounting a deflection coil, and a neck glass welded to the yoke portion for storing an electron gun; A glass funnel for a cathode ray tube having a body portion formed between an opening end and a yoke portion, wherein a central axis Z of each neck glass is set to a high vacuum when a cathode ray tube is manufactured using the glass funnel. Therefore, the neck glasses located on both sides of the tube axis A are provided in the yoke portion so as to be parallel to the tube axis A extending perpendicularly to the screen from the center of the screen. A glass funnel for a cathode ray tube, which is welded so as to be inclined outward. A body portion having a substantially rectangular opening end, a plurality of yoke portions for mounting a deflection coil, and a neck glass welded to the yoke portion for storing an electron gun; A cathode ray tube glass funnel having a body portion formed between an open end and a yoke portion, and a pair of yoke portions located on both sides of a tube axis A of a cathode ray tube manufactured using the glass funnel. When the distance between the axes at the tip of the neck glass at the center axis Z of the neck glass is D ₁ and the distance between the axes at the welded portion to the yoke portion is D ₂ , D ₁ > glass funnel for a cathode-ray tube, characterized in that a D _2.