JPH0624101B2 - Picture tube device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a picture tube (hereinafter referred to as CRT) used in a television receiver, a computer terminal, or the like.
It relates to the device.

[Conventional technology]

Regarding CRT reinforcement technology, for example, National Repor
“Voluntary tube reinforcement technology” by Haruki Nakamichi in “Vol.8, No.2 Apr, 1979, pp. 77-284”.

The CRT conventionally used has a rectangular screen, and its schematic structure is as shown in FIG. 3 (A). FIG. 3 (A) is a side view which is generally used as a shade mask type color CRT and is shown with a part cut away.

In FIG. 3 (A), the CRT 1 comprises a panel screen portion 2A, a panel 2 forming a panel side surface portion 2B, a funnel-shaped funnel 4 connected to the panel 2, and a neck portion 5 including an electron gun (not shown). It is a vacuum glass container.

A fluorescent screen 3 is provided on the inner surface of the panel screen portion 2A, and a shadow mask 6 having an innumerable number of holes is arranged facing the fluorescent screen 3. Since the fluorescent screen 3 is composed of a plurality of fluorescent bodies and the screen 3 needs to be configured, the shed mask 6 needs to be attached and detached from the panel 2 multiple times, and accordingly, the panel 2 and the fan panel 4 are required.
Are separated, and the panel 2 and the funnel 4 are sealed with a fritted glass which is a glass solder. This part is the frit seal portion 7.

In the CRT 1 as such a glass vacuum container, scratches or the like attached to the glass may expand and lead to destruction called "implosion". In order to prevent this, the paper tape 8 is usually wrapped around the panel side surface portion 2B, and the metal band 10 is placed over the paper tape 8.
Is wound and tightened, and an explosion-proof treatment is performed to prevent cracks generated on the panel screen portion 2A side from extending to the frit seal portion 7 side.

Also, a mounting ear 9 for mounting the CRT 1 on the receiver
Are clamped and fixed at the same time when the metal band 10 is wound.

FIG. 3 (B) is a front view of the CRT 1, and the square fluorescent screen 3 is shown as X, Y, and
Define the Z and P axes. Z is a tube axis, which coincides with the center of the screen 3.

By the way, in such a CRT 1, in a usual design, the panel screen portion 2A is deformed by drawing a vacuum so as to draw contour lines having substantially the same shape (square shape) as the square screen 3. The broken line in FIG. 4 shows the contour line of the displacement.

This means that the main stress in the vicinity of the center of the rectangular side (the direction along the X and Y axes in the panel screen portion 2A) becomes larger than the diagonal direction P of the screen 3,
The shaded area in the figure indicates the location where the principal stress is large.

FIG. 5 shows the CRT 1 in only 1/4 of the first quadrant,
The line that includes the center and runs along the Y-axis of the CRT tube wall is
A. And similarly define each line along the X-axis diagonal
It is defined as LA and DA.

As can be seen from FIG. 5, the end portion of the panel screen portion 2A, that is, the edge portion 2C, the panel side surface portion 2B, the vicinity of the frit seal portion 7 and the like are problematic points in terms of the strength of the CRT.

FIG. 5 shows the stress of a vacuum CRT without the metal band 10. Further, FIG. 6 shows a type called a band reinforced type with a rim which is generally performed in a large CRT, which has a rim bent portion 11A and a rim side portion 11B on a panel side surface portion 2B.
(Not shown in FIG. 6) is provided, an adhesive 12 such as an epoxy resin is interposed between the metal rim 10 and the panel side surface portion 2B, and the metal band 10 is wound thereon as a tension band. While being turned and tightened, the metal band 10 is tightened via the reinforcing plate 13 and the mounting ear 9.

This explosion-proof type is more expensive than the explosion-proof structure shown in Fig. 3 (A), and is mainly used for large-scale. The metal band 10 is different from the type shown in FIG. 3 (A).
The bottom part is the rim bending part 11A, and the rim side part is wound around the entire side surface of the panel (actually,
The lower part is a two-division type) and the lower part, that is, the panel side surface part 2B, is provided with an adhesive 12 made of an adhesive resin.
The main point is that they are bonded together.

When actually hitting, the adhesive 1
2 is applied beforehand, and the rim bending portion 11A is provided on the CRT 1,
Attach the rim side surface portion 11B, and then from above, the metal band 10
Tighten and complete the explosion-proof structure.

In the band-reinforced type described above, the explosion-proof effect is that statically, when the CRT is in a vacuum, part of the panel side surface 2B to the funnel 4 swells to the outside, but the swelling is just below the metal band 10. In, there is an effect of suppressing. That is, the stress under the metal band 10 of the CRT moves to the lower side. In other words, the high stress portion of the panel side surface portion 2B in FIG. 5 is slightly lowered.

However, in reality, when the metal band 10 is tightened, the tension is applied only to the corner portion of the CRT 1, so that the D.D. A. In addition, the panel side surface portion 2B in the direction of 1 is significantly effective, but as shown in FIG. 5, it is ineffective in the direction of the essential SA and LA cross sections. For this reason, the shaded area in FIG. 5 is still the point of caution.

By the way, the standards of each country as a means of measuring the degree of band reinforcement for the explosion-proof effect are to purposely scratch the panel screen portion 2A and give a shock with a metal ball, etc. The final step is to determine how much glass fragments will fly to the front.

In contrast to such dynamic characteristics, the rim bending portion 11A and the rim side surface portion 11B serve to increase the rigidity of the panel side surface portion 2B finally.

Furthermore, the rim has a bent portion 11A on the screen side, but this effect has the effects of (a) further improving the rigidity of the rim and (b) suppressing the glass from jumping to the front side when the glass breaks. is there.

By intentionally imploding the rim-reinforced CRT as described above and observing it in detail, the central portion of the panel screen portion 2A constituting the face screen and its peripheral portion are It is sucked inward, and the screen end portion including the panel side surface portion 2B and the corner portion is not sucked inward and finally pops out toward the viewer (front). The rim bent portion is particularly effective in suppressing the glass from popping out at this portion.

FIG. 7 is a view for explaining a part of the damage state after the CRT is implosed, and the panel part is projected to the back side and the front side, and almost no glass remains. For example, the panel side surface portion 2B is bonded to the rim side surface portion 11A (11B
Indicates a rim bent portion), and only a part of the adhesive is left. On the other hand, the funnel 4 is slightly left to form a shape.

Next, the effect of tightening the metal band 10 will be further described. Statically, by tightening the panel side surface portion 2B with the metal band 10, it is possible to suppress the panel side surface portion 2B from swelling due to vacuum.
(DA)}>} Deform by the size of the center direction of the side (SA and LA)}, and by extension, reduce the deformation of the entire CRT. Therefore, (i) since the vacuum strain is reduced, the breakage that occurs when stress is applied to the glass for a long time is prevented, and the reliability is improved.

(ii) Further, it is very effective in maintaining the shape of the glass bulb by reinforcing the rigidity of the metal band 10 in the process of dynamically breaking the glass bulb in the standard test.

(iii) Further, since the high stress area in the hatched diagram of FIG. 5 is lowered as much as possible, it is useful for suppressing the extension of the glass crack from the panel screen portion 2A side to the frit seal portion 7.

Based on the above-mentioned background, it is considered that the explosion-proof structure passes the standard test and the price is the most important design item.As a result, as a countermeasure, for example, the shape of the rim is only examined. It was

Regarding the glass bulb, for example, even if the thickness distribution is studied to improve the stress distribution shown in FIG. 5, the effect is not sufficient unless the thickness is considerably deviated, or the yield in the manufacturing process deteriorates. It was less practical because it became extreme.

In any case, in the explosion-proof structure, whether the panel side surface portion 2B is fastened with the metal band 10 or the shrink fitting method which has come to be widely used recently, is not limited to fastening the panel side surface portion 2B. Absent. That is, currently C
It is more efficient to tighten the side part of the RT even if the price is included as the explosion-proof structure.

In this way, the shape of the panel 2 has not changed since the initial development of the CRT, despite the importance of tightening the panel side surface portion 2B. That is, the shape of the panel side surface portion 2B having a direct relationship with the explosion-proof structure described above will be described.

FIG. 8 shows the shape of the surface of the mold match line showing the maximum shape portion in the Z-axis cross section of the panel side surface portion 2B, which is usually the portion tightened with the metal band 10. The figure shows the first quadrant (C
Only the upper right portion of the fluorescent screen 3 of the RT panel is shown.

As shown in FIG. 8, the upper and lower parts have a radius of curvature RL,
The right and left side surfaces are composed of a radius of curvature RS, and the corners are smoothly connected to each other with a radius of curvature r smaller than RL and RS, and the center of the radius of curvature is (X0, y0).

FIG. 9 shows only the corner portion in an enlarged manner. The contact point between the radii of curvature RS and r is D1, the contact point between the radii of curvature RL and r is D2, and the center of the radius of curvature r of the corner (x0, y0) is x. , Y
The angles formed with the axial direction are θ1 and θ2, respectively.

Further, the maximum positions of the panel side surface portion 2B in the x and y axis directions are set to xM and yM in FIG.

FIG. 10 illustrates the surface pressure received by the glass side surface portion 2B when the panel side surface portion 2B is tightened with the metal band 10. Since the surface pressure is applied vertically to the side surface, the panel side surface portion 2B is shown in FIG. The magnitude P of the surface pressure is shown in the vertical direction.

Further, the surface pressure PL is constant between yM and D2, D1 to D2 are surface pressure PD, and D1 to xM are constant pressure PS. That is, the metal band 10 is used to fasten a fixed portion with a radius of curvature RL between yM and D2, and the same reason is applied to other portions.

If a concrete example is shown below for a 37-inch CRT, xM =
(391.8.0), yM = (0.309,0), (x0, y0) =
(350.4,262,80), RL = 5521.9mm, RS = 5433.8mm,
r = 35.0 mm, θ2≈5.1 °, θ1≈3.6 °, RL = 5.060
× 10 ^-3 kgf / mm ² , PD = 7.983 × 10 ^-1 kgf / mm ² , PS = 5.1
It is about 42 × 10 ^-3 kgf / mm ² .

What should be noted here is that (i) RL, RS >> r, so that the metal band 10 is mostly predominantly at the corner portion, (ii) θ2> θ1, and (iii) ( The angle between the x-axis and the line connecting the (x0, y0) to the screen center is 36 ° 51'12 ".

Regarding these three points, although there are some numerical differences,
Such a structure is formed up to a size larger than the small size of the CRT.

Here, the direction of the approximate surface pressure load in the case of FIG. 9 will be described with reference to FIG. As mentioned above,
Since the diagonal surface pressure is dominant, the approximate combined load of the surface pressure at the corners is applied in the direction of the angle of the x axis and α as shown in FIG. In the above example, α = θ1 + 1/2 (90- (θ1 + θ2)) = 44.25 °, which is a different direction from 36 ° 52'12 ″. Therefore, this direction intersects the x-axis. Is x more than the center
Crosses in the + direction.

[Problems to be solved by the invention]

By the way, within the standards of each country that need to be satisfied as a CRT device, 15 of UL (Underwriters Laboratory) in the United States
In the impact test with the foot pond energy, as shown in FIG. 12, after inserting the scratch 30 near the screen end in the y-axis (SA-axis) direction, a steel rod with a hemispherical tip called a "missile" is attached to the panel screen part. It hits 2A and judges the scattering condition of glass as explosion-proof performance.

Therefore, as the CRT device, the explosion-proof performance was evaluated in the condition of the bare CRT shown in FIG. 5, the shape of the rim, the condition of the completed CRT device equipped with the adhesive 12 and the metal band 10 and the condition of the scratch 30. I need to put it.

In this test, destruction of the panel screen portion 2A always starts at the scratch 30. Moreover, the broken glass pieces tend to cause cracks in the scratch 30.

Against this background, considering the shape of the panel corners in FIG. 11, θ2 = 5.1 ° and θ1 = 3.6 °, which means that (load from x direction)> (load from y direction). ) Is meant.

That is, when considering the vicinity of the scratch 30, it means that the shape of the corner portion of the conventional panel 2 has many components in the direction of opening the scratch of the scratch 30 due to the metal band 10 and the like. This is because the scratch 30 extends in the x direction.

As is clear from the above, in the conventional CRT, the panel skirt portion is wrapped with paper tape to prevent explosion, and the metal band is wrapped around it and tightened. At this time, the panel screen portion is rectangular. The tightening surface of the metal band becomes maximum at the corner portion, and the surface pressure distribution is determined by the shape of the corner portion. Explosion-proof performance depends on this surface pressure distribution.

The present invention has been made in view of the above points, and an object thereof is to obtain a picture tube device capable of improving explosion-proof performance.

[Means for solving problems]

The image receiving apparatus according to the present invention has a substantially rectangular screen and has a contact point D between the long sides of the panel or the funnel screen and the respective radii of curvature RL and r of the corners.
_The angle θ2 between the line connecting ₂ and the center of the radius of curvature r and the y-axis direction, the line connecting the contact point D ₁ between the radius of curvature RS and r of the short side with respect to the screen and the center of the radius of curvature r, and the x-axis. The angle θ1 with the direction is θ1> ≧ θ2 + 1 °, and the load is applied from the outside to the corner portion and the side.

[Work]

According to the present invention, the load on the panel is θ1θ2 + 1 ° when the load is applied from the outside and the explosion-proof treatment is performed, so that the load is not at least in the direction in which the scratch easily extends.

〔Example〕

An embodiment of the picture tube device of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment thereof,
The maximum shape is shown in the Z-axis cross section of the side surface of the panel of the CRT, and the shape of the surface of the mold match line is the portion that is usually fastened with a metal band, and only the first quadrant is shown.
Further, FIG. 2 is an enlarged view of the corner portion in FIG. In FIGS. 1 and 2, the same parts as those in FIGS. 8 and 9 are designated by the same reference numerals.

FIG. 1 and FIG. 2 are obtained by modifying the conventional 37-inch case (FIG. 8) to the panel of the present invention, where RL = 7000, RS = 4000, r = 35, x ₀ = 350.4. , Y ₀ = 265.0, yM = 308.82, xM = 394.26, where θ1 = 4.07 ° and θ2 = 2.88 °.

In actual manufacturing, not θ1 = θ2, but the radius of curvature r of the long side corresponding to the panel or funnel screen.
, The contact point D ₂ with the radius of curvature r of the corner portion, the angle θ 2 formed by the line connecting the center of this radius of curvature r and the y-axis direction, the radius of curvature RS and the radius of curvature r of the short side corresponding to the screen. When the contact point D ₁ with and the center of this radius of curvature r are connected, the angle θ 1 formed with the x-axis direction is θ 1> θ 2 + 1 °,
It is better to make a difference of about _{1 °} . This is because, for example, the screen 3 has a rectangular shape such as 4: 3, and is determined as the minimum angle for making a difference from the x direction and the y direction. The external weight is applied to the corner and the side.

In this embodiment, as in the conventional CRT, the sides and the corners have a constant radius of curvature.
The gist of the present invention is effective even if the curvature is not constant and is displayed by a mathematical expression.

〔The invention's effect〕

As described above, the present invention has a panel side surface shape in which a tightening surface pressure is applied in a direction to prevent the development of scratches. Therefore, a load is applied to the side surface of the panel or the funnel to provide an explosion-proof effect. The shape of the panel corner can be made in consideration of the scratch direction in the test, and the explosion-proof performance can be improved.

[Brief description of drawings]

FIG. 1 is a view showing the shape of the side surface of the panel of the band B in the first quadrant of the panel screen of an embodiment of the picture tube device of the present invention. FIG. 2 is an enlarged view of the corner portion of FIG. Figure (A)
Is a side view showing the general structure of a conventional CRT partially broken away, FIG. 3 (B) is a view for explaining the screen and coordinate system of the CRT of FIG. 3 (A), and FIG. 4 is a conventional CRT panel. FIG. 5 is a diagram for explaining deformation of the screen portion due to vacuum, FIG. 5 is a diagram for explaining a high stress caused by vacuum in a conventional CRT, and FIG. 6 is a band-reinforced explosion-proof structure used in a conventional large CRT or the like. FIG. 7 is a diagram for explaining the conventional CRT.
8 is a view for explaining the damage situation of the panel part when the implosion of FIG. 8 is performed, FIG. 8 is a view showing the shape of the first quadrant of the side surface part of the conventional CRT panel, and FIG. 9 is shown in FIG. FIG. 10 is a view for explaining the details of the corner portion, FIG. 10 is a view for explaining the distribution when a load is applied from the outside as a conventional CRT explosion-proof structure, and FIG. 11 is for forming the corner portion of FIG. FIG. 12 is a diagram for explaining the relationship between the radius of curvature that is formed and the radius of curvature that forms the side, and FIG. 12 is a diagram that illustrates the position of the scratch in the standard test of the conventional CRT. 1 …… CRT, 2A …… Panel screen, 2B ……
Panel side, 3 ... Screen, 4 ... Funnel,
10, 10A, 10B ... metal band, 11 ... rim,
11A: rim bent portion, 11B: rim side surface portion, 1
2 ... Adhesive, RL ... Radius of curvature on the long side of panel side surface, RS ... Radius of curvature on the short side of panel side surface, r ...
Curvature radius of the corners on the side of the panel, RL, PS, PD ...
…load. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A line connecting a radius of curvature RL of a long side corresponding to a screen of a panel or a funnel and a contact point D _{2 of a} radius of curvature r of a corner portion and a center of the radius of curvature r. The angle θ2 with the y-axis direction, the contact point D ₁ between the curvature radius RS of the short side corresponding to the screen and the curvature radius r of the corner, and the line connecting the center of this curvature radius r and the x-axis direction. The angle θ1 is θ1θ2 + 1 °, and the picture tube device is characterized in that a load is applied from the outside to the corner portion and the side. 2. A picture tube device according to claim 1, wherein the radii of curvature have a relationship of RL> RS.