JP3110085B2 - Cathode ray tube - Google Patents

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 a cathode ray tube which scans a phosphor screen formed on a flat face plate by dividing the phosphor screen into a plurality of regions.

[0002]

2. Description of the Related Art In recent years, various studies have been made on a high-definition picture tube having a high-definition broadcast or a large screen associated therewith. Generally, in order to achieve high resolution of a picture tube, the spot diameter of an electron beam on a phosphor screen must be reduced. On the other hand, conventionally, the electrode structure of the electron gun has been improved or the electron gun itself has been increased in diameter and lengthened, but no satisfactory results have yet been obtained. This is mainly because the distance from the electron gun to the phosphor screen becomes longer as the tube becomes larger, and the magnification of the electron lens becomes too large. Therefore, in order to realize high resolution, it is important to shorten the distance (depth) from the electron gun to the phosphor screen. In this case, wide-angle deflection increases the magnification difference between the center and the periphery of the screen. For this reason, wide-angle deflection is not advantageous for achieving high resolution.

For this reason, conventionally, a method of arranging a plurality of independent small picture tubes to provide a large screen with high resolution has been disclosed in JP-A-48-90428, JP-A-49-21019, and Jpn. It is disclosed in, for example, Japanese Patent Publication No. 117130. This type of method is effective for a huge screen display with a large number of divisions arranged outdoors or the like. However, in the case of a medium-sized large screen display with a screen size of about 40 inches, the screen connection portion between the regions is used. Is noticeable and reproduces an unsightly image. Therefore, when used as a home television receiver or as a terminal for graphic display in computer-aided design (CAD), the connection portion of the screen becomes a fatal defect.

On the other hand, US Pat. No. 3,071,7
No. 06, JP-B-39-25641, JP-B-42-4928, JP-B-50-17167, etc. disclose a structure in which a plurality of independent picture tube cleans are integrated. Have been. As shown in FIG. 9, a picture tube having a phosphor screen of this integrated structure includes a face plate 2 on which a phosphor screen 1 is formed, a rear plate 3 opposed to the face plate 2, and a rear plate 3 And a plurality of necks 5 provided on each of the funnels 4 constitute a vacuum envelope. The face plate 2 is made of glass, and the rear plate 3 is made of glass or metal.

However, in such a structure, when the screen surface becomes large, the thickness of the face plate 2 and the re-plate 3 must be increased so as to withstand the atmospheric pressure (external pressure), and the tube shaft is required. It is also necessary to have a large curvature in the direction. As a result, the weight of the envelope becomes very heavy, and if the envelope has a large curvature in the tube axis direction, the screen becomes difficult to see. Furthermore, phosphor screen 1
The distance between the lens and the electron gun 6 sealed in the neck 5 increases, and the electron lens becomes unfavorable in magnification.

Therefore, in order to solve the above problems, it is necessary to make the face plate have a relatively flat and large area. In this case, it is necessary to provide a support means for supporting the atmospheric pressure applied to the face plate. Required.

The provision of such a supporting means is known in connection with a solar heat collector for evacuating the inside of an envelope.
106353, JP-A-62-272432, JP-A-62-285335, JP-A-63-1
28532, JP-A-48-90183, JP-A-64-10553, JP-A-1-117251
No., for example.

FIG. 10 shows an example. In this example, as the support means for supporting the atmospheric pressure applied to the evacuated flat envelope 8, the support means 9 comprising an elongated plate-shaped support is used.
Is arranged. Others have a needle-like support arranged.

The support means 9 made of a long and thin plate-shaped support supports the flat face plate 2 (screen surface) with a wide contact area, thereby preventing the load due to the atmospheric pressure from being concentrated at one point. However, the inventor has found from the various experiments that the supporting means 9 comprising the elongated plate-shaped support has the following problems.

First, the processing accuracy of the support becomes a problem.
That is, as shown in FIG. 11, a black stripe of a phosphor screen (consisting of a stripe-shaped three-color phosphor layer and a black stripe) on the inner surface of the face plate 2 is used.
The end 12 that abuts along 11 must be shaped like a knife edge, and the height of the support must exactly match the distance between the face plate and the rear plate.
For example, when the length of the knife-edge-shaped end portion 12 is about 50 mm or less, such a support can be processed practically and can be mass-produced. Special finishing is required, leading to higher manufacturing costs.

Second, there is a problem in strength due to the support being plate-shaped. Generally, the strength of a plate-like member is strong against a load in the direction along the plate surface, but easily deformed against a load in a direction inclined to the plate surface, and excessive load is applied to the adjacent support. Will be added.

Third, there is a method of attaching the support. That is, since the elongated plate-shaped support is difficult to stand on its own, it is difficult to attach it to the rear plate. A fixing jig for vertically supporting the fixing member is required.

Fourth, there is a problem of warpage. In general, plate-like members are resistant to in-plane deformation, but are easily deformed in directions other than in-plane.
It is easily deformed as shown by 9a in FIG.

Fifth, there is a problem of contact with the face plate. Normally, flat sheet glass is manufactured by a float method, but it is difficult to make the thickness of a sheet glass used for a large face plate or the like uniform over the entire surface by the float method. In general, the thickness distribution of sheet glass is not so different in a relatively narrow range of, for example, about 50 mm unless there is an extreme change in the sheet thickness. ~ 0.1mm
It may be. Therefore, even if the support 9 is accurately processed, the support 9 cannot always be brought into contact with the face plate over the entire length of the end of the support.

Further, it has been found that the needle-shaped support has the following problems.

First, there is the problem of the number required to support atmospheric pressure. That is, the plate-shaped support can have a relatively large contact area with the face plate, but the needle-shaped support is extremely narrow. Therefore, in order to reduce the load on each support, it is necessary to arrange a large number of supports. Specifically, although it depends on the thickness and size of the face plate, it is necessary to arrange needle-like supports at an arrangement pitch of 10 mm or less, and to form a phosphor screen having a diagonal dimension of 20 inches. In order to support the atmospheric pressure applied to the face plate, more than 1000 supports are required.

Second, there is a problem of processing accuracy. That is, the needle-like support needs to have a needle-like tip.
In general, the needle-like processing of a wire can be relatively easily performed by cylindrical polishing or the like, but in this case, it is difficult to accurately align the needle-like tip with the center axis of the wire, and the needle-like tip is usually biased. Formed with heart.

Third, there is a problem in strength due to the needle shape of the support. That is, like the case of the plate-shaped support, the needle-shaped support is strong against the axial load of the wire, but easily deforms against the load in the direction inclined with respect to the axis, Excessive loads will be applied to adjacent supports.

Fourth, there is a method of attaching a support. That is, as in the case of the plate-shaped support, it is difficult for the thin needle-shaped support to stand on its own. When joining to a member or a rear plate, a fixing jig for vertically supporting the member is required.

In short, the support means composed of a plate-like or needle-like support has many problems in terms of structure, processing, assembly, cost, etc., and is not practically preferable.

Further, as shown in FIG. 10 (b), many of the known flat cathode ray tubes have a plurality of linear cathodes 14, a control electrode 15, an acceleration electrode 16, a deflection electrode 16 in an envelope 8, as shown in FIG. Since the electrodes 17 and the like are arranged, the structure becomes very complicated,
There are many problems in mass production. Also, as the screen becomes larger,
Manufacturing becomes difficult. Further, as the number of electrodes and supporting means increases, the amount of gas released from these members increases, which causes problems such as deterioration of the life characteristics of the cathode ray tube.

In order to solve the problems of the plate-like and needle-like supports described above, the present inventor has made the end shape on the face plate side into a wedge shape 19 as shown in FIG. It has been found that even when the end interval L of the shape 19 is set to 2 to 30 mm and the number of the support means 9 is reduced, the load applied to the face plate by the atmospheric pressure can be effectively supported. However, it has been found that the following problem still exists even when the supporting means is configured in this manner.

That is, when the face plate is supported by the support means 9 having a wedge-shaped end interval L of 15 mm, for example, as shown in FIG. Both ends are larger than the center and the change is steep, and the load is not applied uniformly over the entire length between the wedge-shaped ends.

As a result of various experiments and computer simulations to investigate the cause of the non-uniformity of the load, the non-uniform stress distribution 20 is caused by the deformation of the face plate at the portion where the support is not arranged. It became clear that it was the effect of. In this case, the deformation amount in question is as small as about 0.5 mm, but the supporting means having the knife-edge-shaped tip, that is, the wedge-shaped end interval L
In the case of a supporting means having a large value, the influence becomes extremely large.

Referring to FIG. 15, the influence of the atmospheric pressure acts uniformly on the entire surface of the face plate 2 as indicated by an arrow 21, but the amount of deformation of the face plate 2 due to the atmospheric pressure comes into contact with the support means 9. Part is almost zero,
It is maximum between the support means 9 and the adjacent support means. More specifically, the amount of deformation of the portion that comes into contact with the support means 9 is not constant over the entire length between the ends of the wedge shape 19 of the support means 9 and is zero at both ends. May rise from. As a result, the support means 9 supports the load applied to the face plate 2 by the atmospheric pressure at both ends of the wedge shape 19, and the stress generated in the face plate 2 concentrates on the portions corresponding to the both ends of the wedge shape 19. And
In the middle part between the both ends, the stress distribution is smaller than that, and the stress distribution at the both ends is sharp.

The stress distribution of the face plate shown in FIG. 14 varies depending on the magnitude of the load applied to the support means and the size of the wedge-shaped end interval L of the end of the support means on the face plate side. The middle of both ends of the wedge does not float,
The face plate may be in close contact with the entire length between both ends and the stress distribution may be concentrated at both ends, or the ends may be deformed so as to bite into the face plate.
However, in either case, when the face plate contacts over a certain length, stress concentrates on the portion that contacts both ends.

Therefore, even if the support means having the end on the face plate 2 side in the form of a wedge 19 is used, the load applied to the face plate 2 due to the atmospheric pressure cannot be effectively supported, and the end gap of the wedge shape cannot be used. By making L longer,
Even if the load applied to the portion in contact with the both ends can be reduced, concentration of the load on the both ends is unavoidable and poses a practical problem.

[0028]

As described above, a cathode ray tube having a high resolution, a short depth, an easy-to-view screen, a simple structure, practicality, and high industrial value has a flat face plate. There are various problems when trying to obtain a cathode ray tube of a type in which the phosphor screen formed on the inner surface is divided into a plurality of regions and scanned, and it is difficult to solve the problem with the conventional technology. Therefore, in order to effectively support the load applied to this flat face plate by the atmospheric pressure, the inventor has made the end of the support means on the face plate side into a wedge shape, and has set the end interval of the wedge shape. 2-3
A 0 mm cathode ray tube was developed. However, if a support means having a wedge-shaped end on the face plate side is used,
It has been found that the load applied to the face plate by the atmospheric pressure is supported by the wedge-shaped ends, and the load is not applied uniformly over the entire length between the wedge-shaped ends, so that the stress distribution generated on the face plate cannot be made uniform.

The present invention has been made to solve the above problems, and has a flat face plate.
An object of the present invention is to provide a cathode ray tube of a type in which a phosphor screen formed on an inner surface thereof is divided into a plurality of regions for scanning, and has a structure for effectively supporting a load applied to a face plate by atmospheric pressure.

[0030]

SUMMARY OF THE INVENTION A substantially rectangular flat first member is provided.
A vacuum, comprising a plate, a side wall extending substantially perpendicularly from the periphery of the first plate, and a substantially rectangular flat second plate disposed parallel to and opposed to the first plate via the side wall. An enclosure, supporting means disposed between the first and second plates, a phosphor screen adhered to an inner surface of the first plate, and a plurality of phosphor screens disposed on the second plate side. And a beam emitting means for emitting an electron beam for scanning by dividing into regions. In a cathode ray tube, an end of the supporting means disposed between the first and second plates on the first plate side has a wedge shape. The length of the support means at the center of the wedge is longer than the length at both ends.

[0031]

As described above, the end of the support means disposed between the first and second plates on the first plate side has a wedge shape, and the length at the center of the wedge shape of the support means is set at the both ends. If the length is longer than the length, the load applied to the first plate by the atmospheric pressure is supported by the entire length between the ends of the wedge shape, and the concentration of the stress at the both ends of the wedge shape generated by the atmospheric pressure on the first plate is dispersed, and the uniformity is obtained. Can be

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments.

FIG. 1 is a perspective view of a color cathode ray tube according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views taken along lines AA and BB, respectively. FIG. 4 shows a supporting means as a main part configuration, FIG. 5 shows an exploded perspective view, and FIG. 6 shows a plan view.

The cathode ray tube is joined to a substantially rectangular flat glass face plate 30 (first plate) and a peripheral portion of the face plate 30 to form a face plate.
A side wall 31 extending substantially perpendicular to 30 and this side wall
It comprises a substantially rectangular flat glass rear plate 32 (second plate) opposed to and in parallel with the face plate 30 via 31 and a plurality of funnels 33 joined to the rear plate 32. It has a vacuum envelope 34. As shown in FIG. 4, a plurality of openings 35 are formed in the rear plate 32, and the plurality of funnels 33 are respectively joined to the openings.

Further, on the inner surface of the face plate 30,
A striped three-color phosphor layer that emits blue, green, and red light;
A phosphor screen 36 comprising black stripes provided between the three color phosphor layers is formed, and a shadow mask 37 having a large number of electron beam passage holes formed inside thereof is opposed to the phosphor screen 36. Are located.
In each of the necks 38 provided in the plurality of funnels 33, an electron gun 39 is provided. Further, between the face plate 30 and the rear plate 32, a support means 40 including a plurality of columnar supports is provided through a support through-hole formed in the shadow mask 37.

In the cathode ray tube, each electron beam emitted from the plurality of electron guns 39 is deflected horizontally and vertically by a deflection yoke (not shown) mounted outside each funnel 33. As a result, the phosphor screen 36 is divided into a plurality of small areas through a shadow mask 37.
R1, R2, R3,. The raster drawn on the phosphor screen 36 by the divided scanning is connected by a signal applied to the electron gun 39 and the deflection yoke, and has a structure in which one large raster is drawn on the entire surface of the phosphor screen 36. .

The support means 40 is for supporting a load applied to the face plate 30 and the rear plate 32 of the vacuum envelope 34 by the atmospheric pressure, and is made of a metal round bar.
As shown in FIG. 4, the end 41 on the face plate side
Has a slightly wedge-shaped distal end as shown by the height difference H. And this support means 40
The length direction of the wedge shape abuts against the black stripe of the phosphor screen 36, and along the length direction, the small regions R1, R2, R3 divided and scanned by the electron beam.
…, Located at each intersection of R20.

Specifically, the size of the phosphor screen 36 formed on the inner surface of the face plate 30 is 406.4.
mm × 304.8 mm, the distance between the face plate 30 and the rear plate 32 is 20 mm, the support means 40 has a round bar portion having a diameter of 10 mm, a length on its central axis of 20 mm, and a width W of a wedge-shaped portion. Is 0.5 mm, and the length L of the wedge-shaped portion is 10 mm, which is the same as the diameter of the round bar portion. Then, the length direction of the wedge shape abuts against the black stripe of the phosphor screen 36, and the length of the wedge shape portion matches the longitudinal direction of the black stripe, and the small regions R1 and R2 divided and scanned by the electron beam. , R3 ..., R20 at each intersection.

By arranging the support means 40 having the above-described shape between the face plate 30 and the rear plate 32, the following operation and effect can be obtained.

That is, the stress generated on the face plate due to the atmospheric pressure generally depends on the number and spacing of the support means disposed therebetween, but the stress on the face plate side end of the support means which directly contacts the face plate. When the area is small, the contact area of each support means with the face plate and the shape of the contact portion are more dominant than the number and arrangement intervals of the support means.

FIG. 7A shows the result of computer simulation of the stress distribution 42a generated on the face plate when the support means 40 is arranged between the face plate and the rear plate. FIG. 7 (a)
Is the case where the length on the central axis of the support means 40 is 10 mm, the tip of the wedge shape on the face plate side is curved, and the length at both ends of the wedge is shortened by 0.1 mm (H =
0.1 mm). The stress distribution 42b shown in FIG. 13B is a comparative example in which the length of the supporting means is set to 10 mm and the wedge-shaped tip is flattened.

As is clear from the comparison between FIGS. 7A and 7B, when the wedge shape at the end on the face plate side is curved as in the support means of this example, both ends of the wedge shape are bent. Of the wedge-shaped tip becomes uniform over the entire length of the wedge-shaped tip.

Therefore, by using the support means 40 of this embodiment, it is possible to effectively support the face plate 30 and reduce the number of the support means 40 and to reduce the number of the end portions on the face plate side. It is possible to shorten the length of the wedge. Further, by shortening the length of the wedge shape, it becomes easy to align the front end portion along the black stripe of the phosphor screen 36 when assembling the cathode ray tube. Further, ripple effects such as simplification of processing of the support and reduction of the manufacturing cost can be obtained.

In the above embodiment, the support means is formed of a metal round bar and the cross section on the rear plate side is circular. However, as shown in FIGS. 8 (a) and 8 (b), This support means 40 may have a narrow or wide rectangular cross section on the rear plate side. Further, as shown in (c) and (d), the tip of the end on the face plate side has a shape in which both ends are linearly dropped from the flat center, or the center and both ends. May be flattened to form a step 44 formed therebetween.

In the above embodiment, a plurality of independent support means are arranged between the face plate and the rear plate. However, a part or all of the support means can be integrated.

Further, in the above embodiment, the support means is formed of metal, but the support means may be made of other materials such as glass and ceramics.

In the above embodiment, the cathode ray tube in which the electron gun is disposed inside the neck of the funnel joined to the rear plate has been described. However, the present invention relates to a cathode ray tube which combines a line cathode and electrostatic deflection. Applicable to pipes.

Although the above embodiment has been described with reference to a color cathode ray tube, the present invention can be applied to a cathode ray tube other than a color cathode ray tube.

[0049]

According to the present invention, the support means disposed between the substantially rectangular flat first plate and the substantially rectangular flat second plate arranged in parallel to the first plate is provided by the first means. If the end on the plate side is formed in a wedge shape, and the length of the support means at the center of the wedge shape is made longer than the length at both ends of the wedge shape, the wedge shape generated on the first plate due to the atmospheric pressure is reduced. By dispersing the concentration of stress at both ends, it is possible to support the load due to the atmospheric pressure over the entire length between the wedge-shaped ends. Therefore, the number of support means for supporting the load applied to the first plate by the atmospheric pressure can be reduced. In addition, the length of the wedge shape of the end of the support means on the first plate side can be shortened, so that the arrangement of the support means with respect to the phosphor screen formed on the inner surface of the first plate becomes easy and the processing of the support body itself is simplified. Thus, effects such as reduction of manufacturing cost can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA.

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4A is a perspective view of a supporting means as a main part configuration, and FIG. 4B is a view showing a shape of an end on a face plate side thereof.

FIG. 5 is an exploded perspective view for explaining a configuration of the color cathode ray tube.

FIG. 6 is a front view of the color cathode ray tube.

7 (a) is a diagram showing a stress distribution generated on the face plate due to atmospheric pressure, and FIG. 7 (b) is a graph showing a stress distribution generated on the face plate of the previously developed cathode ray tube shown for comparison. FIG.

8 (a) to 8 (d) are diagrams showing different shapes of the support means.

FIG. 9 is a diagram showing a configuration of a conventional cathode ray tube.

FIG. 10 (a) is a perspective view showing a configuration of a conventional color cathode ray tube in which a supporting means is arranged, and FIG. 10 (b) is a cross-sectional view showing an enlarged main part configuration.

FIG. 11 is a view showing an arrangement of support means for a phosphor screen of the conventional color cathode ray tube.

FIG. 12 is a view for explaining a problem of a conventional supporting means.

FIG. 13 is a view showing the shape of the support means developed earlier.

FIG. 14 is a diagram showing a stress distribution generated on the face plate by the atmospheric pressure developed earlier.

FIG. 15 is a diagram for explaining the occurrence of stress distribution on the face plate due to the atmospheric pressure of the previously developed cathode ray tube.

[Explanation of symbols]

 30 ... face plate 31 ... side wall 32 ... rear plate 33 ... funnel 34 ... envelope 36 ... phosphor screen 38 ... neck 39 ... electron gun 40 ... support means R1-R20 ... small area

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-65041 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29/87 H01J 31/00

Claims (1)

(57) [Claims] 1. A first plate having a substantially rectangular flat shape, a side wall extending substantially perpendicularly from a peripheral portion of the first plate, and disposed parallel to the first plate via the side wall. A vacuum envelope having a substantially rectangular flat second plate; and a vacuum envelope disposed between the first and second plates, the end of the first plate being formed in a wedge shape. A supporting means whose length at the portion is longer than the length at both ends; a phosphor screen adhered to the inner surface of the first plate; and a plurality of regions arranged on the second plate side, and And a beam emitting means for emitting an electron beam which is divided and scanned.