JPH05290754A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide a color cathode-ray tube of high quality by preventing the deformation due to the tension of a shadow mask. CONSTITUTION:A slit 73 is formed in each corner for connecting a long edge 71 and a short edge 72 of a mask frame 7. Displacement of the long edge of the mask frame 7 is thereby not coupled with the short edge, and the conversion of electron beam passing holes of a shadow mask near the short edge due to the displacement of the mask frame is avoided to facilitate the correction of landing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask structure having a structure for avoiding the deformation of the shadow mask due to the displacement of the mask frame holding the shadow mask which determines the arrival position of the electron beam on the phosphor screen. The present invention relates to a color cathode ray tube.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube includes an outer peripheral connecting a panel, a funnel and a neck, a fluorescent screen formed on the inner surface of the panel, and an electron gun for emitting a plurality of electron beams for exciting and emitting light. A shadow mask that is arranged in close proximity to the phosphor screen and has a number of slots that are electron beam passage holes arranged therein;
The shadow mask structure comprises a mask frame for welding and fixing the shadow mask.

Recent color cathode ray tubes tend to flatten their panels, which necessitates flattening of the shadow mask. FIG. 7 is a cross-sectional view for explaining a schematic structure of this type of shadow mask type color cathode ray tube, in which 1 is a panel, 2 is a funnel, 3 is a neck, 4 is an electron gun, 5 is a deflection yoke, and 6 is a fluorescence. A body screen, 7 is a mask frame, and 8 is a shadow mask.

In FIG. 1, a mask frame 7 and a shadow mask 8 welded and fixed to the mask frame 7 are opposed to the phosphor screen 6 formed on the inner surface of the panel 1.
A shadow mask structure consisting of and is arranged. Neck 3
An electron beam R emitted from an electron gun 4 arranged inside,
G and B are designed to land on the phosphors of the corresponding color of the phosphor screen 6 by this shadow mask 8.

In the flattening of the shadow mask accompanying the flattening of the panel (hereinafter, also referred to as flattening), there is a problem in that the flatness of the shadow mask must be ensured. In order to ensure the planar uniformity of the shadow mask, a flat shadow mask is applied with a unidirectional tension to be fixed by welding to the mask frame.

As a method of applying tension to the shadow mask, for example, as disclosed in Japanese Patent Laid-Open No. 62-249339, the shadow mask is heated and thermally expanded, and in this state, it is welded to the mask frame. The tension is generally applied by utilizing the contraction of the shadow mask accompanying the temperature decrease.

[0007]

However, when a non-rigid frame such as a so-called press frame made by pressing a plate material is used as the mask frame, the mask frame is deformed by the tension applied to the mask. In a shadow mask with slot-type electron beam passage holes, the tension on the long side is so strong that when the long side of the mask frame is displaced inward, the short side is displaced outward, opposite to the displacement of the long side. .. For this reason, when the electron beam hits the mask and the tension is weakened by heating, the mask frame deforms, and in the type of color CRT in which the stripes of the phosphor are formed in parallel with the short axis, there is a color shift at the center of the short side. It is easy to happen. Since this movement moves oppositely on the long side and the short side, there is a problem that it is difficult to correct with a spring such as a lever.

FIG. 8 is a diagram for explaining this movement. 7 is a mask frame, 71 is a long side, 711 is a long side deformed by receiving tension, and 712 is a length in a state where the tension is weakened by heating. A side, 72 is a short side, 721 is a short side deformed by receiving tension, 722 is a short side in a state where the tension is weakened by heating, and 8 is a shadow mask. In the figure, when fixing the shadow mask 8 to the mask frame 7, the shadow mask 8 is heated, or the mask frame 7 is deformed so that a larger tension is applied between the long sides than between the short sides. , The shadow mask 8 to the long side 7 of the mask frame 7.
1 and the short side 72 are welded.

The present invention solves the above problems and provides a color cathode ray tube having a shadow mask structure using a mask frame having a structure in which movement on the long side and movement on the short side do not work together or are difficult to work together. The purpose is to provide.

[0010]

In order to achieve the above object, the present invention is directed to whether the movement of the long side and the movement of the short side are interlocked with the corner portion of the mask frame constituting the shadow mask structure. Alternatively, it is characterized by having a structure that is difficult to interlock. That is, according to the present invention, an outer peripheral that connects the panel 1, the funnel 2 and the neck 3, a phosphor screen 6 formed on the inner surface of the panel 1, and a plurality of electrons that excite the phosphor screen 6 to emit light. Beam R,
Electron gun 4 for emitting G and B, and the fluorescent screen 6
A shadow mask structure which is arranged close to and facing the fluorescent screen 6 and has a shadow mask 8 for projecting the plurality of electron beams onto a predetermined position of the phosphor screen 6 and a mask frame 7 holding the shadow mask 8. In the provided color cathode ray tube, a slit 73 cut in a cross-sectional direction from the shadow mask joining surface of the mask frame 7 at a connecting portion between the short side 72 and the long side 71 of the mask frame 7 forming the shadow mask structure. Is provided to prevent transmission of deformation of the long side with respect to the short side.

Further, according to the present invention, along the longitudinal direction of the long side 71 of the mask frame 7 which constitutes the shadow mask structure, a plurality of slits 74 cut in the inner circumferential direction from the outer circumferential side of the long side 71 are formed. It is provided to prevent the deformation of the long side from being transmitted to the short side. Furthermore, the present invention provides a pair of substantially rectangular frame bodies 710, 7 in which the shadow mask structure is joined at the contact portions of the parallel sides.
20. Each of the frame bodies 710 and 720 has a structure in which the front and back sides of the frame bodies 710 and 720 are interchanged at the corner portions (connection portions of the long side and the short side). It is characterized by being joined with a shadow mask.

The present invention can also be used by combining the slits 73 and 74 described above, and is particularly effective when applied to a so-called press frame which is press-molded as a mask frame.

[0013]

When the slit is provided at the connecting portion of the long side 71 and the short side 72 of the mask frame 7, the deformation of the long side 71 is not transmitted to the short side 72 side at the slit portion (or this transmission is small. However, even if the long side 71 is deformed by the tension applied to the shadow mask 8, the deformation of the short side 72 is extremely small.

Further, in the case where a plurality of slits 74 are provided in the longitudinal direction of the long side 71, the deformation of the long side 71 due to the tension applied to the shadow mask 8 is absorbed by the slits of the long side itself. The short side 72 is not deformed. Then, a pair of substantially rectangular frame bodies 710 and 720 in which the mask frames are joined at the contact portions of the respective parallel sides are used, and each of the frame bodies 710 and 720 has its corner portion (the connecting portion of the long side and the short side). ), The frame 7 is formed by the tension applied to the shadow mask.
Since the deformation of 10 is independent of the frame 720, the displacement of the electron beam passage hole near the short side of the shadow mask welded and fixed to the frame 720 does not occur.

As described above, according to the present invention, the long side and the short side of the mask frame are separated so that mutual deformations are not transmitted at the corners, so that the short side is interlocked with the movement of the long side. Or the electron beam passage hole near the short side is not displaced due to the tension of the shadow mask applied between the long sides, and a color cathode ray tube with good color reproducibility can be obtained.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1A and 1B are explanatory views of a first embodiment of a mask frame constituting a shadow mask structure used in a color cathode ray tube according to the present invention. FIG. 1A is a plan view, FIG. 1B is a sectional view in the long side direction, and FIG. It is a short side direction sectional view.

The mask frame 7 is a so-called press frame and has a large diameter on the side of the phosphor screen, and the long side 71 and the short side 72 on the side of the large diameter which face the side of the phosphor screen (shadow). The shadow mask structure is constructed by welding and fixing a shadow mask to the mask joint surface). In this embodiment, a slit cut in the cross-sectional direction from the shadow mask joining surface of the mask frame is provided at a corner portion that is a connecting portion between the long side 71 and the short side 72,
Transmission of deformation of the long side with respect to the short side is prevented.

FIG. 2 is an enlarged plan view of an essential part of a corner portion of the mask frame shown in FIG. 1, and FIG. 3 is a sectional view taken along line AA of FIG. As shown in FIG. 2, a slit 73 is provided at a corner portion of the mask frame 7, the slit 73 being cut from the outer peripheral side of the mask frame in the inner peripheral direction. As can be seen from FIG. 3, the slit 73 functions so that the movement of the long side 71 for welding the shadow mask 8 is separated from the short side 72. Therefore, the tension of the shadow mask 8 causes the long side 71 to move as shown in FIG. Even if it deforms as shown, the short side 72 does not deform.

As the plate material used for the mask frame 7,
For example, the thickness of stainless steel material with a low coefficient of thermal expansion is 2.3 m.
Use m. The major axis L, which is the dimension in the long side direction, is 40.
4 mm, the minor axis S, which is the dimension in the short side direction, is 306 mm, and the height H, which is the dimension in the tube axis direction, is 36 mm. In this mask frame 7, as described with reference to FIG.
When 1 is displaced toward the center, the short side 72 moves outward. If the long side 71 and the short side 72 move in opposite directions, the so-called Q dimension control of the shadow mask structure is adversely affected.

The slit 73 has a width of 1 m, for example.
A shadow mask made of an iron plate having a plate thickness of 0.025 mm is welded and fixed on the long side and the short side, or only the long side, on the mask frame 7 having a depth of m and a depth of 12 mm. As a result, even if the slot type shadow mask 8 is welded and fixed to the long side 71 and the short side 72 of the mask frame 7, it is possible to avoid displacement of the slot near the short side, which causes color misregistration, which is excellent. Color reproduction is possible.

To correct the displacement of the mask frame with respect to the panel, a cantilever spring support mechanism is used to correct the color misregistration. FIG. 4 is an explanatory view of a second embodiment of a mask frame constituting a shadow mask structure used for a color cathode ray tube according to the present invention. In this embodiment, a plurality of slits 74 are formed in a long side 71 in a longitudinal direction thereof. is doing.

FIG. 5 is an enlarged plan view of an essential part of a corner portion of the mask frame shown in FIG. In this embodiment, the slit 74 is the slit 73 of the first embodiment.
However, the width, depth, or mutual interval of the shadow mask may be appropriately selected so that deformation of the shadow mask due to tension is not locally biased.

According to this structure, the deformation of the long side due to the tension of the shadow mask is absorbed by the existence of the plurality of slits 74 and is not transmitted to the short side 72 side. In addition, a slit 73 similar to that of the first embodiment may be provided at a corner portion where the long side 71 and the short side 72 are connected. FIG. 6 is a perspective view of an essential part for explaining a third embodiment of a mask frame constituting a shadow mask structure used in a color cathode ray tube according to the present invention.

In the present embodiment, the mask frame 70 has a double frame structure in which two frame bodies made of pipe frames are welded at their contact portions, and the long side 710 side and the short side 720 to which the shadow mask is welded. The frame is separate from the side. That is, the mask frame 70 is composed of a pair of substantially rectangular frame bodies joined at the contact portions of the respective parallel sides, and the long side 710 of one frame body and the short side 72 of the other frame body.
0 has a structure in which the front and back are interchanged at the corner portion (the connecting portion of the long side and the short side), and the shadow mask is joined to the long side 710 of one frame body and the short side 720 of the other frame body. The shadow mask may be welded only on the long side.

In this structure, when the long side 710 of the shadow mask which is welded is displaced by the tension of the shadow mask, the non-welded side of the mask on the short side of the frame forming the long side 710 is displaced. In the case of the entire circumference welding of the shadow mask and the mask frame, the frame body to which the shadow mask on the short side 720 side is welded is interlocked with the displacement on the long side 710 side of the frame body to which the shadow mask on the long side is welded. Does not displace. In the case where the shadow mask is welded only to the long side 710, the portion where the spring mechanism for supporting the mask frame to the panel is welded is a frame body different from the frame body to which the shadow mask is welded and fixed. The displacement of the long side 710 does not interlock. Therefore, the displacement does not affect the operation of the spring mechanism.

Therefore, according to this embodiment, a highly accurate shadow mask structure can be constructed with a lightweight pipe frame, and the displacement of the electron beam passage hole due to the tension of the shadow mask can be avoided and the color reproducibility is improved. A colored cathode ray tube can be obtained. In this embodiment, the mask frame has a double frame structure composed of two pipe frames. However, for example, a step is provided on the short side portion of a normal mask frame, and another member is fixed to the mask frame. It has been confirmed that the same effect can be obtained by welding a shadow mask to.

In the above embodiments, the electron beam passage hole of the shadow mask is described as a slot type, but the present invention is not limited to this, for example, a shadow mask having a circular type electron beam passage hole or a flat type. It can also be applied to the shadow mask of.

[0028]

As described above, according to the present invention, the movements of the long side and the short side of the mask frame for welding and fixing the shadow mask are not linked or difficult to be linked, so that the electrons associated with the thermal deformation of the shadow mask It is possible to provide a color cathode ray tube in which the drift of the beam is easily corrected and the color shift is unlikely to occur.

[Brief description of drawings]

1A and 1B are explanatory views of a first embodiment of a mask frame which constitutes a shadow mask structure used in a color cathode ray tube according to the present invention, in which FIG. 1A is a plan view and FIG.
(C) is a sectional view in the short side direction.

FIG. 2 is a plan view of an essential part showing an enlarged corner portion of the mask frame shown in FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an explanatory view of a second embodiment of a mask frame constituting a shadow mask structure used in a color cathode ray tube according to the present invention.

5 is a plan view of a principal part showing an enlarged corner portion of the mask frame in FIG. 1. FIG.

FIG. 6 is a perspective view of a principal part for explaining a third embodiment of a mask frame constituting a shadow mask structure used in a color cathode ray tube according to the present invention.

FIG. 7 is a sectional view illustrating a schematic structure of a shadow mask type color cathode ray tube.

FIG. 8 is a schematic diagram illustrating deformation of the long side and the short side of the mask frame.

[Explanation of symbols]

 1 Panel 2 Funnel 3 Neck 4 Electron Gun 5 Deflection Yoke 6 Fluorescent Screen 7,70 Mask Frame 8 Shadow Mask 71,710 Long Side 72,720 Short Side 73,74 Slit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kawasaki 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd.

Claims (2)

[Claims] 1. A peripheral device connecting a panel, a funnel and a neck, a phosphor screen formed on the inner surface of the panel, and an electron gun for emitting a plurality of electron beams for exciting and emitting the phosphor screen. A shadow mask, which is arranged close to and facing the phosphor screen, and is configured to project a plurality of electron beams at a predetermined position on the phosphor screen, and a mask frame holding the shadow mask. In a color cathode ray tube having a structure, a slit cut in a cross-sectional direction from the shadow mask joining surface of the mask frame is provided at a connecting portion between a short side and a long side of the mask frame forming the shadow mask structure. Is a color cathode ray tube. 2. An outer peripheral connecting a panel, a funnel and a neck, a phosphor screen formed on the inner surface of the panel, and an electron gun for emitting a plurality of electron beams for exciting and emitting the phosphor screen. A shadow mask, which is arranged close to and facing the phosphor screen, and is configured to project a plurality of electron beams at a predetermined position on the phosphor screen, and a mask frame holding the shadow mask. In a color cathode ray tube having a structure, the shadow mask structure is composed of a pair of substantially rectangular frame bodies joined at contact portions of parallel sides, and each frame body is replaced by a long side and a short side. A color cathode ray tube, wherein the shadow mask is joined to the long side of one frame body and the short side of the other frame body.