JPH0877936A - Color cathode ray tube - Google Patents

Abstract

(57) [Summary] [Object] To provide a color cathode ray tube provided with a slot-type shadow mask in which surface vibration is suppressed. [Structure] A mask frame structure 12 including two parallel bars 13 and a pair of arms 14 for holding the two bars in parallel, and a slot type in which tension is applied between the two bars 13. The shadow mask 1 and a vibration attenuator 61 having one end in contact with the end side of the slot type shadow mask 1
Was set up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask type color cathode ray tube, and more particularly to a color cathode ray tube having a slot type shadow mask having a vibration damping function.

[0002]

2. Description of the Related Art A color cathode ray tube which is widely used at present is a so-called shadow mask type color cathode ray tube. The function of the shadow mask provided in the color cathode ray tube is that the three electron beams emitted from the electron gun are separately applied to the inner surface of the panel constituting the vacuum envelope, and the three colors of red, green, and blue fluorescent light are applied. The purpose is to selectively control the path of each electron beam so that each body is divided into and collides with each other.

This kind of shadow mask generally has a thin plate of iron or an iron-nickel alloy having a small coefficient of thermal expansion and has a round hole, a rectangular shape, or a comb-shaped electron beam passage hole. Phosphors of three colors are formed as described above in a shape corresponding to the shape of the electron beam passage hole of the shadow mask. Then, the shadow mask having a round hole electron beam passage hole is a dot type shadow mask, the shadow mask having a rectangular electron beam passage hole is a slot type shadow mask, and the one having a blind electron beam passage hole is a grill type shadow mask. I will call it.

Usually, the dot-type shadow mask and the slot-type shadow mask are often pressed into a spherical shape, and the grill-type shadow mask is held in a cylindrical shape by applying vertical tension. The shadow mask has a problem in that the temperature of the shadow mask rises due to the collision of the electron beam during the operation of the cathode ray tube so that the shadow mask is thermally expanded, and the electron beam passage hole is displaced to cause the landing position shift of the electron beam.

In recent years, the demand for high-definition display is increasing for color cathode ray tubes, and as the precision of image display increases, the electron beam passage hole is displaced on the fluorescent screen due to the thermal expansion of the shadow mask. The need to highly suppress the deviation of the landing position of the electron beam has become stronger and stronger. In order to reduce the above thermal expansion, expensive iron with a small thermal expansion coefficient as a constituent material of the shadow mask
A nickel alloy is used, or a shadow mask is stretched and held by applying tension to the mask frame.

In the above-mentioned shadow mask which is stretched and held by tension, the grill type shadow mask is stretched in a cylindrical shape (a part of the cylindrical surface) by applying tension in the vertical direction of the image display surface. When doing so, there is a problem in that the grilles that make up the shadow mask are entangled with each other, which makes handling difficult. In order to solve the above problems,
For example, as disclosed in U.S. Pat. No. 4,973,283, it has been attempted to apply a tension to a dot type shadow mask or a slot type shadow mask to hold it in the mask frame.

[0007]

As described above, an iron / nickel alloy having a small coefficient of thermal expansion may be used as a constituent material of a dot type shadow mask or a slot type shadow mask to be press-molded. It is extremely expensive, and it is difficult to reduce the thickness of the shadow mask, and it is difficult to achieve higher resolution.

Further, in the case of a grill type shadow mask, the grill is entangled with each other, making it difficult to handle, and it is very difficult to reduce the thickness of the shadow mask to a certain extent from the viewpoint of mechanical strength. I have no choice but to inevitably increase the weight.
On the other hand, in the slot type shadow mask, an attempt has been made to apply tension to the shadow mask and fix it to the mask frame.

In this case, even if the shadow mask is thinned, the bridge does not cause the problem that the grills are entangled with each other, and the rigidity of the mask frame does not need to be so high. Therefore, the shadow mask structure is light as a whole. There is an advantage that you can. However, in the slot type shadow mask, if the plate thickness of the shadow mask is thinned, in the method of welding and fixing the slot type shadow mask by applying tension only in the vertical direction of the display image surface, the slot type shadow mask is applied to the slot type shadow mask by external force. There is a problem that vibration occurs and the image quality is deteriorated.

Since the slot type shadow mask has a structure in which bridges are present between the grills, each grill does not vibrate individually like a string unlike the grill type shadow mask. , The shadow mask causes the surface to vibrate. When this vibration occurs, the position of the slot is changed, the landing position of the electron beam with respect to the phosphor is changed, and the color purity is lowered.

The vibration can be reduced by increasing the mask plate thickness and the bridge width. However, in both cases, there arise problems such as an increase in weight of the mask frame and deterioration of display image quality. The purpose of the present invention is to
It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a color cathode ray tube equipped with an inexpensive, lightweight, high-quality slot type shadow mask.

[0012]

In order to achieve the above object, the present invention comprises a panel having a phosphor screen formed on the inner surface thereof, a neck for accommodating an electron gun, and a funnel for connecting the panel and the neck. In a color cathode ray tube having a vacuum envelope and at least a shadow mask structure having a slot type shadow mask suspended in the panel,
The shadow mask structure is composed of a mask frame and a shadow mask stretched over the mask frame, and a vibration damping body is brought into contact with non-hole portions at both ends of the shadow mask.

That is, the first invention according to claim 1 is a mask frame structure composed of two parallel bars and a pair of arms for holding the two parallel bars in parallel.
In a color cathode ray tube having a shadow mask structure having a slot type shadow mask fixed by applying tension between the two parallel bars, a vibration damping body is brought into contact with an edge of the slot type shadow mask. It is characterized by

A second aspect of the present invention is characterized in that the vibration damping body is brought into contact with a non-hole portion at an edge of the slot type shadow mask. further,
According to a third aspect of the present invention, one end of the vibration damping body has a leg portion fixed to the arm, and the other end has a substantially T-shape that includes a head portion that abuts on an edge of the slot shadow mask. It is characterized by being a plate body.

The fourth invention according to claim 4 is
The slot type shadow mask stretched over the mask frame structure is a part of a cylindrical surface having a curvature in the extending direction of the bar. The vibration attenuator is not limited to the T-shape whose one end is fixed to the arm constituting the mask frame structure, but the one end is brought into contact with at least one position of the end portion of the slot type shadow mask. Any shape may be used as long as it has an effect of suppressing the surface vibration of the shadow mask.

The present invention is not limited to the slot type shadow mask, but can be applied to the dot type shadow mask.

[0017]

With the above structure, tension is applied only to the top and bottom of the display image surface of the slot type shadow mask, and even if the welded shadow mask structure starts to vibrate, vibration is generated in the mask non-hole portion through the bridge. It is suppressed by propagating and contacting the vibration damping body to be damped.

That is, in the structure of the first aspect of the invention, the pair of arms of the mask frame structure including the two parallel bars and the pair of arms for holding the two parallel bars in parallel and the slot type. The vibration attenuator installed between the shadow mask and the edge of the shadow mask suppresses the vibration of the slot type shadow mask, which is surface-vibrated by the application of an external force, at the edge thereof and quickly suppresses the vibration.

Further, in the structure of the second aspect of the invention, the abutting force can be secured by abutting the vibration attenuator on the non-hole portions at both edges of the slot type shadow mask. Further, in the configuration of the third aspect of the invention, since the vibration damping body is a substantially T-shaped plate body, the contact area between the head and the slot shadow mask can be increased, and vibration can be further reduced. It can be suppressed in a short time.

Then, in the configuration of the above-mentioned fourth invention,
Since the slot shadow mask is a part of the cylindrical surface having a curvature in the extending direction of the two bars, the surface vibration direction is mainly the extending direction of the bar, and the vibration damping installed on the arm side. Attenuation suppression by the body can be sufficiently achieved.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a schematic sectional view for explaining a first embodiment of a color cathode ray tube according to the present invention, in which 1 is a slot type shadow mask, 12 is a mask frame structure, and 1 is a mask frame structure.
3 is a bar, 14 is an arm, 21 is a panel, 22 is a funnel, 23 is a neck, 24 is a fluorescent screen, 26 is an internal magnetic shield, 27 is a deflection yoke, 28 is a reinforcing band, 30 is a pin, 31 is an electron gun, Reference numeral 61 is a vibration damping body, and 72 is a suspension spring.

In the figure, the panel 21 and the funnel 2 are shown.
A vacuum envelope is formed by 2 and the neck 23, and the three electron beams R, G, B emitted from the electron gun 31 housed in the neck 23 are deflected by the deflection yoke 27 in two directions, horizontal and vertical. , Undergoing color selection in the slot which is the electron beam passage hole provided in the slot type shadow mask 1,
It impinges on a predetermined phosphor that constitutes the phosphor screen 24.

Each electron beam R, G, B is driven by a drive signal given to a control electrode forming the electron gun 31, and 3
A predetermined color image is expressed with a predetermined current ratio of the electron beam of the book. The slot type shadow mask 1 is stretched and fixed to the mask frame structure 12 with tension, and the panel 21
It is suspended and supported by a suspension spring 72 on the pin 30 embedded in the side wall. This suspension spring is installed on at least three sides of the mask frame,
Other springs are not shown in the figure.

FIG. 2 is a perspective view for explaining the structure of the slot type shadow mask structure mounted on the color cathode ray tube according to the first embodiment of the present invention shown in FIG.
The same reference numerals correspond to the same parts, 2 is a grill, 3 is a bridge, 4 is a slot, 5 is a non-perforated portion, 71 and 72 are suspension springs, and 81 is a base plate. The slot type shadow mask 1 has a vertical (vertical side: short side) size of 300 mm, a horizontal (horizontal side: long side) size of 400 mm, and a 0.025 mm thick iron plate with a width of 0.075 mm. Rectangular holes (slots) each having a length of 0.9 mm are arranged in a plane with a vertical pitch of 1.0 mm, a horizontal pitch of 0.3 mm, and a length of about 280 mm and a width of about 380 mm.

In other words, the grill 2 having a width of 0.225 mm and a length of 280 mm is connected by the bridge 3 having a width of 0.1 mm and a pitch of 1.0 mm. As shown in the drawing, the positions of the bridges 3 are deviated by half a pitch between the adjacent grills, and the bridges 3 are at the same position in the horizontal direction for every other grill.

The mask frame structure 12 is made of chromium-based stainless steel and has a cross section of 5 mm in thickness and 1
2 parallel to each other with an L-shape with a side length of 10 mm
A bar 13 of a book is supported by two opposing arms 14 of the same material having a square shape of 10 mm square. One end of a suspension spring 71 is fixed to a predetermined portion of the arm 14 by welding or the like, and a hole formed at the other end is engaged with a pin erected on the inner surface of the side wall of the panel.

Further, one end of the vibration damping body 61 having a substantially T shape, that is, the T-shaped leg portion is fixed to the arm 14 by welding or the like, and the T-shaped head portion is provided with a slot type shadow mask. It is installed so as to abut on one end side. Further, a base plate 81 is fixed to a predetermined portion of the bar 13, one end of a suspension spring 72 is welded to the base plate 81, and a hole formed at the other end is engaged with a pin erected on the inner surface of the panel. It is designed to let you.

The suspension spring is attached to the mask frame structure, and the vibration damping body is also attached to each arm. In this embodiment, the vibration damping body 61 is made of chrome-based stainless steel and has a thickness of 1.0 mm.
The slotless shadow mask 1 is in contact with the non-hole portion 5 formed on the end side with a width of about 150 mm.

In general, when a color cathode ray tube having a slot type shadow mask structure to which tension is applied is subjected to a strong impact or an electron beam hits the mask and is heated and expanded to reduce the tension, the slot type shadow mask 1 vibrates. In particular, the type in which the short side is not constrained is less likely to dampen vibration. In order to damp the vibration, the amplitude may be reduced by contact or the like.

The slot type shadow mask 1 is a bridge 3
Because of the existence of the vibration, the vibration of the grill 2 propagates like a wave and reaches the non-hole portion 5 around the shadow mask (edge). In this embodiment, the vibration damping body 61 is brought into contact with the non-masked portion 5 for about 150 mm to damp the above-mentioned vibration.
The larger the area where the vibration attenuator 61 is in contact with the non-masked portion 5 of the mask, the greater the effect, and the greater the effect of contacting the center of the non-masked portion 5 of the mask.

In this embodiment, one end of the vibration damping body 61 is welded to the arm 14 of the frame structure 12 and the other end is brought into contact with the non-masked portion 5. The vibration damping effect of the vibration damping body, as shown in the present embodiment, the desired effect can be obtained by contacting one end with the slot type shadow mask, but instead of contacting, fixing, Alternatively, it may be in elastic contact.

Further, the contact direction does not have to be the back side of the slot type shadow mask as in the present embodiment, and the contact is made from the side surface, or the shape of the slot type shadow mask side or the shape of the vibration attenuator side is appropriately selected. The structure may be such that the slot type shadow mask is brought into contact with or fixed from the front side by applying bending or the like. Another embodiment of the present invention will be described below.

FIG. 3 shows a second embodiment of the color cathode ray tube according to the present invention.
FIG. 2 is a side view of a main part of a slotted shadow mask structure for explaining an embodiment, in which 2 is a slotted shadow mask, and 14
Is an arm, and 61a is a vibration damping body. In this embodiment, a rectangular plate is used as the vibration damper 61a. One of the long sides of the plate is welded to the arm 14 and the other is brought into contact with the slot shadow mask 2. is there.

According to this embodiment, the vibration damping body can be easily manufactured. FIG. 4 shows a third embodiment of the color cathode ray tube according to the present invention.
FIG. 4 is a side view of a main part of a slotted shadow mask structure for explaining an embodiment, in which the same reference numerals as those in FIG. 3 correspond to the same parts,
61b is a vibration damping body. In this embodiment, the vibration damping body 61b is formed in a substantially U shape, both open ends thereof are welded to the arm 14, and the portions connecting the both ends of the U shape are brought into contact with the slot type shadow mask 2. .

According to this embodiment, the weight of the vibration attenuator is reduced and the weight of the color cathode ray tube as a whole can be expected to be reduced.
FIG. 5 is a side view of a main part of a slot type shadow mask structure for explaining a fourth embodiment of the color cathode ray tube according to the present invention. The same reference numerals as those in FIGS.
Is a vibration damping body.

In this embodiment, the vibration damping body 61c is formed in a substantially Y shape as shown in the drawing, its legs are welded to the arm 14, and both ends of the Y shape are brought into contact with the slot type shadow mask 2. It is a thing. Also in this embodiment, the weight of the vibration attenuator is reduced, and the weight reduction of the entire color cathode ray tube can be expected.

FIG. 6 shows a fifth embodiment of the color cathode ray tube according to the present invention.
FIG. 6 is a side view of a main part of a slotted shadow mask structure for explaining an embodiment, in which the same reference numerals as those in FIGS. 3, 4 and 5 correspond to the same parts, and 61d is a vibration damping body. In this embodiment, the vibration damping body 61c has an inverted triangular shape as shown in the figure,
The apex angle portion is welded to the arm 14, and the side connecting the other two corners is brought into contact with the slot type shadow mask 2.

According to this embodiment, the same effect as that shown in FIG. 2 can be obtained, moreover, the number of welding points can be reduced, and the work amount can be reduced. FIG. 7 shows a sixth embodiment of the color cathode ray tube according to the present invention.
FIG. 7 is a side view of a main part of a slotted shadow mask structure for explaining an embodiment, in which the same reference numerals as those in FIGS. 3, 4, 5 and 6 correspond to the same parts, and 61e _{1 and} 61e ₂ are vibration damping bodies. is there.

In the present embodiment, as shown in the figure, the vibration damping body has two ends 61e _{1 and} 61e ₂ each having one end connected to the arm 14.
Are welded to each other, and the other two ends are brought into contact with the slot-type shadow mask 2, respectively. According to this embodiment,
Since the components 61e _{1 and} 61e ₂ use strip-shaped plate bodies, there is an effect that the weight can be further reduced.

In each of the above embodiments, a plate or a pressed plate is basically used as the vibration damping body, but it is not necessarily a plate, and a bar-shaped body is used, for example. Alternatively, one of them may be fixed to the arm, and the other may be contacted with or elastically contacted with or fixed to the slot type shadow mask. Further, as shown in each of the above embodiments, without using a special component as a vibration damping body, for example, the mask frame side of the internal magnetic shield 26 shown in FIG. The same effect can be obtained even if the structure is brought into contact with the portion 5.

The present invention is not limited to the slot type shadow mask as in the above embodiment, but can be used as a means for attenuating the surface vibration of a shadow mask fixed in one direction.

[0042]

As described above, according to the present invention,
Even if the electron beam passage holes of the shadow mask to increase the definition of the displayed image are made small and the array density is increased to increase the electron beam current value, the shadow mask material is an expensive iron / nickel alloy with a small thermal expansion coefficient. Without using
A slot with an excellent function that can use an inexpensive iron plate and can solve the problems of the prior art that the grill is entangled in the manufacturing process of the shadow mask and the handling is difficult, and that a heavy mask frame must be used. It is possible to provide a high-quality color cathode-ray tube using a shadow mask structure.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a color cathode ray tube according to the present invention.

FIG. 2 shows a color cathode ray tube according to the present invention shown in FIG.
It is a perspective view for explaining the structure of the slot type shadow mask structure mounted in the embodiment.

FIG. 3 is a side view of a main part of a slot type shadow mask structure for explaining a second embodiment of the color cathode ray tube according to the present invention.

FIG. 4 is a side view of a main portion of a slot type shadow mask structure for explaining a third embodiment of the color cathode ray tube according to the present invention.

FIG. 5 is a side view of a main portion of a slotted shadow mask structure for explaining a fourth embodiment of the color cathode ray tube according to the present invention.

FIG. 6 is a side view of a main part of a slot type shadow mask structure for explaining a fifth embodiment of the color cathode ray tube according to the present invention.

FIG. 7 is a side view of a main part of a slot type shadow mask structure for explaining a sixth embodiment of the color cathode ray tube according to the present invention.

[Explanation of symbols]

 1 Slot Type Shadow Mask 2 Grill 3 Bridge 4 Slot 5 Mask No Hole 7 Suspension Spring 12 Mask Frame Structure 13 Bar 14 Arm 21 Panel 22 Funnel 23 Neck 24 Fluorescent Surface 26 Inner Magnetic Shield 27 Deflection Yoke 28 Reinforcing Band 30 Pin 31 Electronic Gun 61 Vibration damping body 71, 72 Spring 81 Base plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Tanabe 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Division (72) Inventor Kawa ▲ ▼ ▼ 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd. In the company

Claims (4)

[Claims] 1. A mask frame structure composed of two parallel bars and a pair of arms for holding the two parallel bars in parallel with each other, and a tension is applied between the two parallel bars to fix the mask frame structure. A color cathode ray tube having a shadow mask structure having the slot type shadow mask described above, wherein a vibration attenuator is in contact with an edge of the slot type shadow mask. 2. A color cathode ray tube according to claim 1, wherein the vibration damping body is in contact with a non-hole portion at an edge of the slot type shadow mask. 3. The substantially T-shaped structure according to claim 1, wherein one end of the vibration damping body is fixed to the arm, and the other end is a head that abuts against an edge of the slot shadow mask. A color cathode ray tube characterized by being a plate body forming 4. The color cathode ray tube according to claim 1, wherein the slot type shadow mask stretched over the mask frame structure is a part of a cylindrical surface having a curvature in the extending direction of the bar. tube.