JP2002324498A - Cathode-ray tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube device which is safe against external shock by improving its mechanical strength. SOLUTION: A panel 22 has a face plate 20 which has substantially a flat external surface and a substantially spherical inner surface, a skirt portion 21 extending almost in the vertical direction from the periphery 20C of the face plate 20, and a curved junction portion 23 connecting the periphery of the inner surface of the face plate 20 with the skirt portion 21. An implosion proof band 38 is attached to the outer peripheral portion of the panel 22. Distance (a) refers to the distance between a center of curvature of the curved junction portion 23 and the inner surface of the face plate 20, measured in the direction of the cathode-ray tube axis, and distance (b) refers to the distance between the center of curvature of the curved junction portion 23 and one end of the implosion proof band extending to the funnel side, parallel to the cathode-ray tube axis. In terms of the distances (a) and (b), a parameter A is defined as follows. A=(a+b)/a This invention is characterized in that the value of A is 1 or more and less than 1.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube, and more particularly to an in-line type color cathode ray tube having an explosion-proof band.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, an in-line type color cathode ray tube device comprises a glass panel 1, a funnel 2, and an envelope evacuated from a neck 3 connected to the funnel 2 to a high vacuum. Have. In this envelope, after attaching a phosphor surface, a shadow mask, an electron gun structure, an inner shield for shielding an external magnetic field, and the like, the panel 1 and the funnel 2 are welded and joined with frit glass, and a high vacuum is applied. Manufactured by evacuation. At this time, a stress due to the outside air pressure is generated in the evacuated envelope. The outline of the generated stress varies as shown in FIG. 4, such as partial application of a compressive stress or application of a tensile stress.

When the in-line type color cathode ray tube apparatus is incorporated in a monitor set, a stress acting on a panel surface exposed to the outside is seen. In the vicinity of the part, a tensile stress acts. It is conceivable that an impact is applied to the exposed portion of the panel 1 due to some kind of accident, and it is important that the glass is not damaged in such a situation.

When a strong impact is applied to the panel 1 from the outside, the glass panel 1 may be damaged.

[0005] The strength test of a general envelope will be described.

That is, an iron ball attached in a pendulum shape to an envelope arranged at a predetermined position is dropped from a predetermined height to collide with the panel 1. When the iron ball collides with the panel surface, a compressive stress acts on the impacted portion. Due to this compressive stress, a tensile stress acts on its peripheral portion. When the tensile stress exceeds the allowable value of the glass, a crack is generated from the portion where the tensile stress is strong, and the panel is broken.

As shown in FIG. 4, a compressive stress is generated in the central portion of the panel 1, so that the tensile stress generated by the impact of an iron ball hardly exceeds the allowable value of glass. However, since the peripheral portion of the panel 1 has an area where a tensile stress is generated, when the tensile stress due to the impact of the iron ball is added, the allowable value of the glass easily exceeds the allowable value, and breakage occurs. I do.

For this reason, as shown in FIG. 3, an iron explosion-proof band 5 is attached around the panel 1 of the envelope. The explosion-proof band 5 compresses the panel surface by strongly tightening the side wall of the panel 1. As a result, the compressive stress acts on almost the entire surface of the panel 1, and the tensile stress generated in the peripheral portion of the panel 1 is canceled.
Panel 1 is prevented from being destroyed.

[0009]

Conventionally, an outer surface and an inner surface of a panel of an in-line type color cathode ray tube device have a predetermined radius of curvature. However, in recent years, an in-line type color cathode ray tube device having a flat panel has been put to practical use in order to improve the visibility of a displayed image.

One of the design methods of the in-line type color cathode ray tube device of the flat panel panel is that the outer surface of the panel is substantially flat (completely flat, or the radius of curvature of 50,000 mm or more) and the inner surface of the panel is substantially a single unit. There is a method using a spherical surface. As for the radius of curvature of the inner surface of the panel, it is necessary to select an appropriate radius of curvature according to the size of the in-line type color cathode ray tube device. For example, in a 17-inch diagonal in-line color cathode ray tube device, the radius of curvature of the inner surface of the panel is 1300 mm to 1800 mm.

In the panel thus manufactured, the thickness of the glass is different between the central portion and the peripheral portion, and the thickness of the glass becomes thicker at the peripheral portion. When looking at the display screen from the operator's perspective,
Since the viewing angle is different between the central portion and the peripheral portion of the display screen, the display image of the peripheral portion appears to be raised due to refraction of light. As a result, the image is visually recognized as a natural planar image.

The strength of an in-line type color cathode ray tube device having such a panel against external impact is different from that of a conventional cathode ray tube device in which the outer surface of the panel is not flat. When the panel has a radius of curvature on both the outer surface and the inner surface, the thickness of the panel is generally the same in both the central portion and the peripheral portion. For example, in a 17-inch diagonal in-line type color cathode ray tube device, the thickness of the panel is 11 at the center.
mm, and about 13 mm in the peripheral portion. The panel has a radius of curvature of about 1000 mm and has a dome-shaped cross section. When an impact is applied to the outer surface of such a conventional panel, a compressive stress acts on the impacted point as described above, and a tensile stress acts around the point. At the same time, the dome-shaped panel is slightly deformed and absorbs impact.

On the other hand, in the case of a panel having a flat outer surface and a predetermined radius of curvature on the inner surface (the outer surface has a radius of curvature of 100,000 m).
m, when the inner surface radius of curvature is 1600 mm), and the thickness of the panel is 11 mm at the center portion and 23 mm at the peripheral portion.
The peripheral portion is 10 mm thicker than a panel having a radius of curvature on both the inner and outer surfaces. As a result, when a similar impact is applied to the outer surface of the panel, the panel is not slightly deformed, and the effect of absorbing the impact is lost. for that reason,
A flat-type in-line color cathode ray tube device having such a panel is vulnerable to external mechanical impact, and may cause dangerous destruction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a cathode ray tube device which has improved mechanical strength and is safe against external impact. .

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, a cathode ray tube device according to claim 1 has a face having a substantially flat outer surface and a substantially spherical inner surface. A panel having a plate portion, a skirt portion extending substantially perpendicularly from a peripheral portion of the face plate portion, a connection curve portion connecting the peripheral portion of the inner surface of the face plate portion and the skirt portion, and a skirt of the panel In a cathode ray tube device comprising a funnel including a neck connected to the electron gun assembly, and a metal explosion-proof band attached to the outer peripheral portion of the panel, a center of curvature of the connection curve portion The distance parallel to the tube axis up to the inner surface of the face plate portion is a, and the tube axis of one end of the explosion-proof band extending toward the funnel and the center of curvature of the connection curve portion. When the parallel distance is b, the value of b is positive when the one end of the explosion-proof band is closer to the funnel than the center of curvature of the connection curve, and the one end of the explosion-proof band is connected to the connection curve. When the value of b at the outer surface side of the face plate with respect to the center of curvature is negative, the value of A in the expression represented by A = (a + b) / a is 1 or more and 1.5 or less. It is characterized by.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the cathode ray tube device of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the cathode ray tube device of the present invention, for example, an in-line type color cathode ray tube device, includes a vacuum envelope (glass bulb) 10 made of glass whose inside is evacuated to a high vacuum. . The vacuum envelope 10 has a panel 22, a funnel 24, and a neck 34. The panel 22 has a substantially rectangular face plate portion 2.
0, and a skirt portion 21 extending substantially perpendicularly from the peripheral edge of the face plate portion 20. The funnel 24 is connected to the skirt 21 of the panel 22. The neck 34 is formed in a cylindrical shape, and the funnel 24
Is connected to the small diameter portion.

The panel 22 has a phosphor screen 27 made of a striped or dot-shaped three-color phosphor layer that emits blue (B), green (G), and red (R) light, respectively. It has. Panel 22
Has an explosion-proof band 38 attached to the outer periphery thereof.

The neck 34 has an in-line type electron gun assembly 36 disposed therein. The electron gun assembly 36 has a center beam 35G (corresponding to green) passing on the same horizontal plane and a pair of side beams 35B on both sides thereof.
(Corresponding to blue), 35R (corresponding to red), three electron beams 35B, 35G, 3 arranged in a line in the horizontal axis X direction.
5R is emitted toward the phosphor layer of the phosphor screen 27 along the tube axis Z direction.

The in-line type electron gun assembly 36 has three electron beams at the center of the phosphor screen 14 by decentering the positions of the side beam passage holes of the low-voltage grid and the high-voltage grid constituting the main lens unit. Self-convergence.

The panel 22 is provided with a shadow mask 28 having a color selection function and mounted inside the panel 22 so as to face the phosphor screen 27. This shadow mask 28
Is formed in a substantially rectangular shape, and has a large number of apertures inside. The shadow mask 28 is supported by a substantially rectangular mask frame 30 formed of an iron material or the like. This shadow mask 28 is used for the electron gun 3
The electron beams 35R, 35G, and 35B emitted from 6 are shaped, and a beam spot is projected on a phosphor layer of a specific color on the phosphor screen 27.

Outside the funnel 24, the deflection yoke 3
7 is mounted. The deflection yoke 37 includes three electron beams 35B, 35G, and 3 emitted from the electron gun assembly 36.
A non-uniform deflection magnetic field for deflecting 5R in the horizontal axis X direction and the vertical axis Y direction is generated. This non-uniform deflection magnetic field is formed by a pincushion-type horizontal deflection magnetic field and a barrel-type vertical deflection magnetic field.

In the above-described vacuum envelope 10, the axis extending coaxially with the neck 34 and passing through the center of the phosphor screen 27 is defined as a tube axis Z, and the axis extending perpendicular to the tube axis is defined as a horizontal axis X.
And the axis extending perpendicular to the tube axis and the horizontal axis is referred to as the vertical axis Y.
And

In the color cathode ray tube apparatus having the above-described structure, the three electron beams 35 emitted from the electron gun assembly 36 are used.
B, 35G and 35R are self-converged toward the phosphor screen 27 while the shadow mask 2
Focused on the corresponding phosphor layer on the phosphor screen 27 via the aperture 8.

Then, the three electron beams 35B, 35
G and 35R are scanned in a horizontal axis X direction and a vertical axis Y direction of the phosphor screen 27 via a shadow mask 28 by an asymmetric deflection magnetic field. Phosphor screen 27
Three electron beams 35B, 35G, 35R focused on top
Strikes the phosphor layer, causing it to emit light,
A color image is displayed.

FIG. 2 is a cross-sectional view schematically showing a peripheral portion of a diagonal portion of the panel 22 in the cathode ray tube device shown in FIG. For example, in the case of a face plate 20 having a diagonal size of 17 inches, the outer surface 20A of the face plate 20 has a radius of curvature of about 100000 mm, which is substantially flat. The radius of curvature of the inner surface 20B of the face plate 20 is 1420 mm in the horizontal axis direction of the panel 22, 1380 mm in the vertical axis direction, and 1400 mm in the diagonal axis direction, and can be regarded as a spherical surface having a radius of curvature of 1400 mm. . The radius of curvature of the inner surface 20B of the face plate 20 is 17 inches and 1300 to 180.
In general, the radius of curvature is further increased as the diagonal size increases.

The panel 22 includes a face plate 20 for forming a display screen and an inner surface 2 of the face plate 20.
And a skirt portion 21 that stands substantially perpendicularly to the peripheral edge portion 20C of OB. The end of the skirt 21 is joined to the funnel 24. Skirt part 21
And the inner surface 20B of the face plate 20 are connected by a connection curve portion 23 having a radius of curvature of several millimeters in a smooth curve. In this embodiment, the radius of curvature of the connection curve portion 23 is 8 mm. Panel 22
Since it is manufactured by press molding with a mold, the outer periphery of the joining surface between the upper mold and the lower mold of the mold is generally the largest (in order to easily remove the molded product (in this case, the panel) from the mold). . The maximum outer shape of the panel 22 is referred to as a mold match line ML.

In this embodiment, the explosion-proof band 38 is
Face plate 2 across mold match line ML
0 from the outer surface 20A side to the skirt portion 21. The fastening force of the explosion-proof band 38 is effectively applied on the mold match line ML having the largest outer dimension. Since the tightening force of the explosion-proof band 38 is necessary to generate a strong compressive stress on the face plate 20, a method of more effectively generating a compressive stress on the face plate 20 using the same explosion-proof band 38 is desirable.

In order to effectively generate a compressive stress on the face plate 20, in a flat type in-line type color cathode ray tube device, as shown in FIG. 5, the position of the mold match line ML in the tube axis direction Z is, as shown in FIG. Face plate 2
0 is provided in a section having a curvature. That is, the mold match line ML is located between the central portion of the inner surface 20B of the face plate portion 20 and the peripheral portion 20C of the inner surface 20B of the face plate portion 20 in the tube axis direction.

In the in-line type color cathode ray tube device according to this embodiment, the explosion-proof band 38 is attached based on the following rules. That is, as shown in FIG. 2, the height of the panel 22 of the in-line type color cathode ray tube device according to this embodiment is 65 mm, and the mold match line ML is located on the outer surface 20A side of the face plate 20 in the tube axis direction. 15mm from (panel front side)
And the joining surface 24A with the funnel 24
It is at a position of 50 mm. The width of the explosion-proof band 38 is 2
One end of the explosion-proof band 38 is disposed so as to extend from the mold match line ML to a position 18 mm closer to the funnel 24, and the other end of the explosion-proof band 38 is connected to the outer surface 20A of the face plate 20 from the mold match line ML. It extends to a position of 10 mm on the side (panel front side). The position of one end of the explosion-proof band 38, that is, the end of the funnel 24 side, matches the center O of the curvature of the connection curve portion 23 on the inner surface 20 </ b> B of the face plate 20.

When the glass bulb is evacuated to a vacuum,
The stress inside the glass around the face plate 20 is:
As shown in FIG. 6, a tensile stress acts because the skirt portion 21 is sucked toward the inside of the vacuum.

Next, when the outer peripheral portion of the panel 22 is tightened by the explosion-proof band 38, it can be considered as follows.

That is, the position of one end (the end on the funnel 24 side) of the explosion-proof band 38 is such that the compressive stress is efficiently applied to the face plate 20 even if it is over the outer surface 20A of the face plate 20 or over the funnel 24 side. Cannot be generated. Considering that the position of the other end of the explosion-proof band 38 (the end on the outer surface 20A side of the face plate 20) is fixed, if the position of the one end is appropriate, as shown in FIG. Compressive stress can be applied. If the position of one end of the explosion-proof band 38 is too close to the outer surface 20 </ b> A of the face plate 20, the contact area between the explosion-proof band 38 that applies the tightening force to the face plate 20 and the outer peripheral portion of the panel 22 is insufficient, and the tightening force is insufficient. . On the other hand, when the position of one end of the explosion-proof band 38 is too close to the funnel 24 side, as shown in FIG.
In order for the explosion-proof band 38 to tighten the skirt portion 21,
A tensile stress is generated on the outer surface 20A of the face plate 20, and the compressive stress is offset.

Therefore, a destructive test was carried out using a prototype in-line type color cathode ray tube device by changing the mounting position of the explosion-proof band 38 and the conditions of the plate thickness. In this destructive test, an iron ball with a diameter of 51 mm was dropped in a pendulum shape from a height of 1.4 m,
The method was performed by a method of colliding with a face plate of an in-line type color cathode ray tube device.

Here, the mounting position of the other end of the explosion-proof band 38 (the end on the outer surface 20A side of the face plate 20) is fixed, and the mounting position of the one end of the explosion-proof band 38 (the end on the funnel side) is variously changed. To perform a destructive test.
The thickness of the explosion-proof band 38 is 0.8 mm and 1.0 m.
Similar destruction tests were performed on four types of m, 1.2 mm and 1.5 mm. Then, tests were performed under these conditions, and the crack occurrence rates of the glass bulb were recorded and compared. The superiority was determined by the crack occurrence rate of the glass bulb.

Here, the position of one end of the explosion-proof band 38 is represented as follows. In other words, as shown in FIG. 2, a straight line parallel to the pipe axis direction Z passing through this point O from the center of curvature O of the connection curve portion 23 and the inner surface 20 of the face plate 20.
Let a be the distance to the intersection with B, and let b be the distance parallel to the tube axis direction Z from the center of curvature O of the connection curve 23 to the end of the explosion-proof band 38 on the funnel side. The value of b is such that one end of the explosion-proof band 38
The case where the end of the explosion-proof band 38 is closer to the face plate 20 than the center of curvature O of the connection curve portion 23 is positive when the case 3 is closer to the funnel 24 than the center O of curvature.

When A = (a + b) / a, the value of A is an index indicating the position of the explosion-proof band on the funnel side.

FIG. 9 shows the explosion-proof band 38 when the position of the other end of the explosion-proof band 38 is fixed and the position of the one end is changed.
FIG. 4 is a diagram showing the relationship between the width of a circle and the value of A.

The example shown in FIG. 2 corresponds to the case where the value of A is 100%, in which one end of the explosion-proof band 38 extends to the center of curvature O of the connection curve 23. If the value of A exceeds 100%, it indicates that one end of the explosion-proof band 38 further extends to the funnel 24 side. Conversely, if the value of A is less than 100%, one end of the explosion-proof band 38 Does not reach the curvature center O of the connection curve 23.

FIG. 10 is a graph showing the relationship between the value of A under each condition and the crack occurrence rate of the glass bulb.

As shown in FIG. 10, the value of A is 100%
In the range of (1) or more and 150% (1.5) or less, the crack occurrence rate was remarkably reduced. A value is 100%
If less than, it is not possible to apply a strong compressive stress to the face plate, and if the value of A exceeds 150%,
It is presumed that the tightening force of the skirt portion increases, tensile stress is generated on the face plate, and the compressive stress originally required by the explosion-proof band is canceled out, so that the crack generation rate sharply increases.

As shown in FIG. 10, when the thickness of the explosion-proof band is 1 mm or more, the value of A is 100% or more and 150% or more.
In the following range, the crack generation rate can be suppressed to 30% or less, and a stronger compressive stress can be applied to the face plate.

As described above, according to the cathode ray tube device of the present invention, the metal explosion-proof band is attached to the outer peripheral portion of the panel, and the mounting position of the explosion-proof band is defined as described above, so that the high vacuum It is possible to generate an effective compressive stress on the face plate of the glass bulb arranged at the position. Thereby, the mechanical strength of the glass bulb of the in-line type color cathode ray tube device can be improved, and an in-line type color cathode ray tube device that is safe against external impact can be provided.

[0044]

As described above, according to the present invention, it is possible to provide a cathode ray tube device with improved mechanical strength and safe against external impact.

[Brief description of the drawings]

FIG. 1 is a partial horizontal sectional view schematically showing a structure of an in-line type color cathode ray tube device according to an embodiment of the cathode ray tube device of the present invention.

FIG. 2 is a cross-sectional view schematically showing a peripheral portion of a diagonal portion of the panel in the cathode ray tube device shown in FIG.

FIG. 3 is a diagram showing a structure of a conventional in-line type color cathode ray tube device.

FIG. 4 is a diagram for explaining stress generated in a panel in the conventional cathode ray tube device shown in FIG.

FIG. 5 is a diagram showing a relationship between a position of a mold match line in the cathode ray tube device shown in FIG. 1 and a mounting position of an explosion-proof band.

FIG. 6 is a diagram for explaining a stress generated in a peripheral portion of a face plate.

FIG. 7 is a diagram for explaining a stress generated in a peripheral portion of a face plate when an explosion-proof band is attached.

FIG. 8 is a diagram for explaining a stress generated in a peripheral portion of the face plate when an explosion-proof band extending too much to the funnel side is attached.

FIG. 9 is a diagram for explaining the value of A that defines the attachment position of one end of the explosion-proof band.

FIG. 10 is a diagram showing a relationship between a value of A and a crack occurrence rate of a glass bulb under each condition.

[Description of Signs] 10 ... Vacuum envelope 20 ... Face plate 21 ... Skirt 22 ... Panel 23 ... Connection curve 24 ... Funnel 27 ... Phosphor screen 28 ... Shadow mask 34 ... Neck 36 ... Electron gun assembly 38 ... Explosion proof band

Claims (3)

[Claims] 1. A face plate having a substantially flat outer surface and a substantially spherical inner surface, a skirt extending substantially perpendicularly from a periphery of the face plate, and a periphery of the inner surface of the face plate. A panel having a connection curve portion connecting the portion and the skirt portion; a funnel connected to the skirt portion of the panel and including a neck for inserting the electron gun assembly; and a peripheral portion of the panel. In a cathode ray tube device comprising: a metal explosion-proof band; and wherein a is a distance parallel to a tube axis from a center of curvature of the connection curve portion to an inner surface of the face plate portion, and extends toward the funnel side of the explosion-proof band. The distance parallel to the pipe axis between the one end and the center of curvature of the connection curve is defined as b, and the one end of the explosion-proof band is located before the center of curvature of the connection curve. The value of b when it is on the funnel side is positive, and the b when the one end of the explosion-proof band is closer to the outer surface of the face plate than the center of curvature of the connection curve portion.
Where the value of A is negative, the value of A in the formula represented by A = (a + b) / a is 1 or more and 1.5 or less. 2. The explosion-proof band according to claim 2, wherein a maximum outer shape portion of the panel is located in a tube axis direction from a central portion on an inner surface of the face plate portion to a peripheral portion on an inner surface of the face plate portion. The cathode ray tube device according to claim 1, wherein the portion extends to a maximum outer shape portion of the panel. 3. The cathode ray tube device according to claim 1, wherein the thickness of the explosion-proof band is 1 mm or more.