JP3112033B2 - Color cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a flat panel,
The present invention relates to a color cathode ray tube in which the vibration of a shadow mask caused by external vibration is rapidly attenuated, so that an adverse effect on image display does not easily appear.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional color cathode ray tube. After the funnel 2 having the neck portion 1 and the panel 3 are formed on the inner surface of the face plate portion 5 of the panel 3 as shown in FIG. 3, the peripheral edge of the panel skirt and the peripheral edge of the funnel opening end are lowered. The tube is formed by fusing with melting point frit glass. A shadow mask holding structure 7 for determining a position at which the electron beam reaches the fluorescent surface (beam landing spot) is disposed opposite to the fluorescent surface 6 formed on the inner surface of the face plate portion 5 of the panel 3. The three electron beams 9 emitted from the electron guns 8 dedicated to the respective primary colors arranged on the same side pass through specific slits of the shadow mask 11 and then split, and correspond to the specific slits of the fluorescent screen 6, respectively. Light is emitted by striking the phosphor stripe of the specified primary color. Therefore, if the relative position between the specific stripe of each color phosphor and the specific slit of the corresponding shadow mask is not accurately maintained, problems such as color misregistration occur.

FIG. 5 shows an example of a conventional shadow mask structure. A mask frame formed by a pair of horizontal frame sides 10a and 10b and vertical arm portions 10c and 10d for holding the frames in opposition to each other. 10 is formed by stretching a shadow mask 11. The shadow mask 11 has a thickness of 0.0
A large number of longitudinal slits having a predetermined shape are arranged at predetermined intervals on a low carbon steel plate of 2 to 0.3 mm by photolithography technology. The shadow mask 11 has its two opposite lateral sides set to the horizontal frame sides 10 of the mask frame 10.
a and 10b are fixed to each other by welding or the like. Even when the shadow mask expands due to heat generated by electron beam impact during operation of the cathode ray tube, if no tension acts on the shadow mask 11 so as not to bend, etc. No. Therefore, when fixing the shadow mask to the mask frame, the shadow mask 11 is fixed to the frame side by seam welding or the like while pressing so that the frame sides 10a and 10b approach each other, and then the pressure is stopped. ,
The tension is applied to the shadow mask by the restoring force of the mask frame. However, the above-mentioned shadow mask holding structure 7 has frame sides 10a and 10b and arm portions 10c and 10c.
d is manufactured separately, then welded and integrated, and the arm 1
Since the required tension is applied to the shadow mask 11 by the elasticity of 0c and 10d, the structure is complicated and the cost is high. It is difficult to maintain the desired dimensional accuracy on the frame sides 10a and 10b after forming the mask frame. However, there is a problem that the weight is further increased. In order to deal with such a problem, for example, Japanese Patent Application Laid-Open No. 55-139743 discloses a mask frame in which the whole is integrally formed into a rectangular frame by press working, and a cut is made in a short side thereof to give elasticity. Is disclosed.

Conventionally, the face plate of a glass panel, including the above-mentioned conventional example, is formed to have a curved surface protruding outward so as to easily withstand implosion. In recent years, flat panel type color cathode ray tubes have come into practical use due to the fact that the technology accumulated over many years of valve manufacturing has made it possible to produce panels that are difficult to implode even when flat. However, when the press-molded mask frame is used for a flat panel color cathode ray tube, the shadow mask vibrates when subjected to vibration from the outside, and a problem such as color misregistration occurs.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and uses a flat-panel-type press-formed mask frame which is simple and inexpensive to produce, while reducing the vibration of the shadow mask in a short time. An object of the present invention is to provide a color cathode ray tube in which an electron beam dedicated to each primary color is prevented from mislanding on a phosphor stripe other than the corresponding specific primary color to cause a color shift or the like. .

[0006]

In order to achieve the above object, according to the present invention, a vertical stripe group of three primary color phosphors which emit light of different primary colors is sequentially and horizontally repeated on the inner surface of a flat panel. And a shadow mask holding structure in which a shadow mask in which longitudinal slit groups are arranged side by side in a lateral direction and is opposed to the fluorescent surface and stretched and held on a mask frame in a plane. In the cathode ray tube, one or more thin wires are provided alternately on both sides of the shadow mask, and are stretched by applying a predetermined tension in the horizontal direction so as to be in close contact with the surface of the shadow mask and substantially perpendicular to the slit. We decided to use the shadow mask holding structure that was used.

[0007]

According to the above-mentioned means, a fine wire for damping the vibration of the shadow mask, that is, a damper wire is tightly attached to both the front and back surfaces of the shadow mask.
Even if the cathode ray tube receives external vibration and the shadow mask tries to vibrate, it is difficult to actually vibrate, and even if it vibrates, the vibration energy is consumed at a number of contact points between the damper wire and the shadow mask due to friction. Occurs, the vibration of the shadow mask is dumped in a short time, and a situation that is troubled by a color shift due to a change in the relative position between the phosphor screen and the shadow mask does not actually occur.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. First, FIG. 3 shows a mask frame 14 used for the shadow mask holding structure according to the present invention. This mask frame was integrally formed into a rectangular frame shape by stamping and press-forming from a 13% chromium stainless steel plate. FIG. 3 (a)
Is a top view thereof, (b) is a lateral sectional view thereof, and (c) is a longitudinal sectional view thereof. As shown, the frame sides 14b and 14
c has a flat portion on which two lateral sides of the periphery of the shadow mask can be fixed by welding. As can be seen from FIG. 3C, the vertical frame side 14a of the mask frame has a wide cut in the vertical direction on the side close to the shadow mask. FIG. 2 is a diagram for explaining how to attach a damper wire, and the like.
As can be seen by looking at (a), (b), (c), and (d) in this order, the support rod 16 for the damper wire is vertically disposed above the cut in the longitudinal periphery of the mask frame. Weld and install. Since the force on the support rod is not so large, the material may be a normal steel wire. However, the curl and the like of the wire are sufficiently removed and straightened. Since it is necessary to use a thin and durable damper wire 13 so as not to disturb the image display, a tungsten wire having a diameter of 15 to 25 μm is used. These damper wires 13 are sandwiched between a U-shaped fitting with a predetermined tension applied to the other end of the leaf spring 12 having one end welded and fixed to the vertical frame side 14a of the mask frame. Further, it is fixed by welding. Since the shadow mask 15 is stretched on the mask frame 14 and does not need to have a self-shape maintaining property, the thickness of the
It was made of a mild steel plate having a thickness of 2 mm, and a number of vertical slits were formed in the horizontal direction by photolithography.
When the shadow mask is thin as described above, the slit manufacturing operation by the photolithography technique can be performed easily and accurately in a short time, and the welding operation to the flat portion of the horizontal side of the mask frame is extremely easy. The operation of fixing the shadow mask 15 to the mask frame 14 under tension is performed by applying pressure from the outside to a predetermined action point on the lateral frame sides 14b and 14c of the mask frame in advance so that they approach each other. At the same time, 20
The shadow mask is welded at a lateral peripheral portion overlapping the mask frame in a state in which the heater heated to 0 ° C. is brought into contact and thermally expanded. After the shadow mask is welded and fixed to the lateral frame sides 14b and 14c of the mask frame, if the pressing force and the heater are removed, the tension of the shadow mask is reduced due to the restoring force of the mask frame and shrinkage due to the temperature drop of the shadow mask. Is applied. After welding and stretching the shadow mask to the mask frame, two damper wires 13 each using a tungsten wire having a diameter of 20 μm were applied to the front and back surfaces of the shadow mask 15 with a tension of 80 g as shown in FIG. In this state, a U-shaped bracket was used to clamp and weld to the end of the leaf spring 12, which had been previously fixed to the vertical frame side 14a of the mask frame by welding. According to the results of the experiment, the tension of the damper wire was 50
~ 150 g was adequate.

FIG. 1A is a top view of a shadow mask holding structure of a color cathode ray tube according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along line AA 'in FIG. 1A. . FIG.
An enlarged plan view of the shadow mask 15 is shown in the center circle of FIG. The structure of the shadow mask holding structure will be apparent from FIG. 1 and FIG. 2 above. Even if the cathode ray tube is vibrated from the outside, the shadow mask hardly vibrates unless it is violently vibrated, and even if large amplitude vibration occurs due to a large shock, the vibration is immediately attenuated by the damper wire. There was no noticeable color shift in a practical state.

[0010]

As described above, in a flat panel shadow mask type color cathode ray tube embodying the present invention,
The electron beam reliably landed on a predetermined phosphor stripe while using a mask frame and a shadow mask which are easy to manufacture, and there was no color shift in a practical state.

[Brief description of the drawings]

1A and 1B are diagrams showing a shadow mask holding structure of a color cathode ray tube according to an embodiment of the present invention, wherein FIG. 1A is a top view thereof, and FIG. 1B is a cross-sectional view taken along line AA ′ shown in FIG. FIG.

FIG. 2 is a diagram for explaining how to attach a damper wire, and FIG. 2 (a), FIG. 2 (b), FIG. 2 (c), and FIG. FIG. 4 is a diagram showing how to attach a damper wire to be tensioned by applying tension and a relationship between the damper wire and a shadow mask.

FIG. 3 is a diagram showing an example of a press-formed mask frame used in the present invention.

FIG. 4 is a schematic sectional view showing an example of a shadow mask type color cathode ray tube.

FIG. 5 is a perspective view showing an example of a conventional shadow mask holding structure of a color cathode ray tube.

[Explanation of symbols]

1 ... neck, 2 ... funnel, 3 ... panel, 4
... tube, 5 ... face plate, 6 ... fluorescent surface,
7: shadow mask holding structure, 8: electron gun, 9: electron beam, 12: leaf spring, 13: damper wire, 14
... Mask frame, 15 ... Shadow mask, 16 ...
Support rod.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-139743 (JP, A) JP-A-62-188133 (JP, A) JP-A-60-127639 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01J 29/07

Claims (2)

(57) [Claims] 1. A phosphor screen in which longitudinal stripes of three primary color phosphors emitting light of different primary colors are sequentially and juxtaposed in the horizontal direction on an inner surface of a panel , and three phosphors are directed toward the phosphor screen. Electronic
An electron gun that emits a beam, and placed close to and facing the phosphor screen
In a color cathode ray tube having the a longitudinal slit group planar obtained by parallel laterally sheet <br/> shadow mask holding structure that was stretched held to the mask frame Yadoumasuku,
The fine line stretched in the transverse direction so as to cross the slits in contact with the surface of the shadow mask, respectively one alternately facing surface was opposed faces an electron gun to the fluorescent screen of the planar shadow mask A color cathode ray tube characterized by being arranged as described above. 2. The fine line corresponds to the fluorescent surface of the shadow mask .
One not a two on each and direction to the surface and the surface facing the electron gun
Contact to a color cathode ray tube according to claim 1, wherein the tungsten wire with a diameter of 15 to 25 [mu] m.