JPH04359841A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide a color cathode-ray tube of flat panel type despite adoption of an easy-to-fabricate mask frame and shadow mask, wherein generation of chromatic misconvergence is completely null in practical application even though vibration is given externally. CONSTITUTION:Longitudinal stripes are laid in line transversely on the inner surface of a flat panel in such a way as closely confronting a fluorescent surface 6, wherein longitudinal slits of three primary color fluorescent substances are laid in line transversely. and thus a thin shadow mask 15 is constructed. This shadow mask 15 is stretched in the form of a plane and held by a mask frame 14 made through single-piece shaping by processing with a press, and each thin wire is stretched over while a certain tension is given in crosswise direction so that it intersects the slits approx. perpendicularly being in tight contact with the surface of the shadow mask 15. One or more of such thin wires are arranged on both sides of the shadow mask 15 alternately on the front and rear.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention has a flat panel,
The present invention relates to a color cathode ray tube in which even if vibrations are received from the outside, vibrations of a shadow mask caused by the vibrations are rapidly attenuated so that an adverse effect on image display is hardly caused.

0002

2. Description of the Related Art FIG. 4 shows an example of a conventional color cathode ray tube. As shown in this figure, after forming a fluorescent surface 6 on the inner surface of the face plate portion 5 of the panel 3, the funnel 2 having the neck portion 1 and the panel 3 are lowered. A tube body is constructed by welding with melting point frit glass. A shadow mask holding structure 7 is disposed opposite to the fluorescent surface 6 formed on the inner surface of the face plate portion 5 of the panel 3 and determines the position where the electron beam reaches the fluorescent surface (beam landing spot). The three electron beams 9 emitted from the electron gun 8 dedicated to each primary color arranged at It hits a phosphor stripe of a specific primary color and emits light. Therefore, if the relative positions of the specific stripes of each color phosphor and the corresponding specific slits of the shadow mask are not maintained accurately, problems such as color shift will occur.

FIG. 5 shows an example of a conventional shadow mask structure, in which the mask frame is formed by a pair of horizontal frame sides 10a and 10b and vertical arms 10c and 10d that hold them facing each other. 10 and a shadow mask 11 stretched thereon. The shadow mask 11 has a plate thickness of 0.0
It is formed by arranging a large number of longitudinal slits of a predetermined shape at predetermined intervals on a low carbon steel plate of 2 to 0.3 mm by photolithography. The shadow mask 11 has two opposing horizontal sides aligned with the horizontal frame sides 10 of the mask frame 10.
A and 10b are fixed by welding or the like, but tension must not be applied to the shadow mask 11 so that it does not bend even when the shadow mask expands due to heat generated by electron beam impact during operation of the cathode ray tube. It won't happen. Therefore, when fixing the shadow mask to the mask frame, the shadow mask 11 is fixed to the frame sides by seam welding or the like while applying pressure so that the frame sides 10a and 10b approach each other, and then the pressure is stopped. ,
Tension is applied to the shadow mask by the restoring force of the mask frame. However, the shadow mask holding structure 7 has frame sides 10a, 10b and arm parts 10c, 10.
d separately and then welded and integrated, mainly arm part 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, and it is difficult to maintain the desired dimensional accuracy on the frame sides 10a and 10b after forming the mask frame. However, there were other problems such as increased weight. In order to deal with such problems, for example, Japanese Patent Application Laid-Open No. 55-139743 discloses a mask frame that is integrally molded into a rectangular frame by press working, and has notches on its short sides to give it elasticity. It has been disclosed to use

In the past, including the above-mentioned conventional example, the face plate of a glass panel was made into a curved surface that protruded outward to easily withstand implosion. In recent years, flat panel color cathode ray tubes have come into practical use, as a result of technology accumulated over many years in valve manufacturing that has made it possible to produce panels that are flat but resistant to implosion. However, when the above press-molded mask frame is used in a flat panel color cathode ray tube, a problem arises in that the shadow mask vibrates when subjected to external vibrations, causing problems such as color shift.

[0005]

[Problems to be Solved by the Invention] The present invention solves the above-mentioned conventional problems, and uses a press-molded mask frame that is flat panel type, has a simple manufacturing process, and is inexpensive. It is an object of the present invention to provide a color cathode ray tube in which electron beams dedicated to each primary color are suppressed from mislanding on phosphor stripes other than the corresponding specific primary color, thereby preventing color shift. .

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, groups of vertical stripes of three primary color phosphors emitting light in different primary colors are sequentially and repeatedly arranged in the horizontal direction on the inner surface of a flat panel. and a shadow mask holding structure in which a mask frame holds a flat shadow mask in which a group of longitudinal slits are horizontally arranged in close opposition to the fluorescent surface. In a cathode ray tube, one or more fine wires are placed in close contact with the surface of the shadow mask and stretched with a predetermined tension in the lateral direction so as to be almost perpendicular to the slits, and are arranged alternately on both sides of the shadow mask. We decided to use a shadow mask holding structure.

[0007]

[Operation] If the above-mentioned method is taken, thin wires for suppressing vibration of the shadow mask, that is, damper wires, are stretched in close contact with both the front and back sides of the shadow mask under tension.
Even if this cathode ray tube is subjected to external vibrations and the shadow mask tries to vibrate, it is actually difficult to vibrate, and even if it does vibrate, the vibration energy is wasted due to friction at the many contact points between the damper wire and the shadow mask. However, the vibration of the shadow mask is damped in a short period of time, and a situation in which color shift occurs due to a change in the relative position between the fluorescent surface and the shadow mask does not occur in practice.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below with reference to the drawings. First, FIG. 3 shows a mask frame 14 used in 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 a 13% chromium stainless steel plate. 3(a) is a top view thereof, FIG. 3(b) is a lateral sectional view thereof, and FIG. 3(c) is a longitudinal sectional view thereof. Frame sides 14b and 14c as shown
has a flat portion, to which two lateral sides of the periphery of the shadow mask can be fixed by welding. As can be seen from Figure (c), the vertical frame side 14a of this mask frame has a wide notch in the vertical direction on the side closer to the shadow mask. Figure 2
is a diagram to explain how to install the damper wire, etc. (
As can be seen by looking at a), (b), (c), and (d) in order, a support rod 16 for the damper wire is welded vertically above the above-mentioned notch on the vertical peripheral edge of this mask frame. and install it. Since the force applied to this support rod is not so large, ordinary steel wire can be used as the material. However, make sure to remove any curls in the wire and keep it straight. Since the damper wire 13 needs to be thin and strong so as not to interfere with image display, a tungsten wire with a diameter of 15 to 25 μm is used. These damper wires 13 have one end welded and fixed to the vertical frame side 14a of the mask frame, and the other end of the leaf spring 12 is fixed with a predetermined tension applied.
Insert it between the U-shaped bracket and weld it in place. Since the shadow mask 15 is stretched over the mask frame 14, self-shape retention is not required, so it is manufactured from a mild steel plate with a thickness of 0.025 mm, and a large number of vertical slits arranged in parallel in the horizontal direction are formed using photolithography technology. Ta. When the shadow mask is thin as described above, the slit manufacturing operation using photolithography can be easily and accurately performed within a short time, and the welding operation to the flat portion of the horizontal frame side of the mask frame is also extremely easy. The work of fixing the shadow mask 15 to the mask frame 14 under tension is performed by applying pressure from the outside to predetermined application points on the horizontal frame sides 14b and 14c of the mask frame so that they approach each other. 20 to shadow mask at the same time
This is done by bringing the shadow mask into contact with a heater heated to 0° C. to cause thermal expansion, and then welding the shadow mask at the lateral peripheral portion where it overlaps the mask frame. After welding and fixing the shadow mask to the horizontal frame sides 14b and 14c of the mask frame, if the pressure and the heater are removed, tension will be applied to the shadow mask due to the restoring force of the mask frame and the shrinkage of the shadow mask as the temperature drops. is applied. After the shadow mask was welded to the mask frame and stretched, a tension of 80 g was applied to two damper wires 13 made of tungsten wire with a diameter of 20 μm on each of the front and back surfaces of the shadow mask 15, as shown in FIG. 2. The leaf spring 1 was fixed in advance by welding to the vertical frame side 14a of the mask frame in the state
A U-shaped metal fitting was inserted into the end of 2 and welded to secure it. According to the experimental results, the tension of the damper wire is 50~
150g was appropriate.

FIG. 1(a) 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. 1(b) is a cross-sectional view taken along the line AA' shown in FIG. 1(a). . Figure 1 (a
) An enlarged plan view of the shadow mask 15 is shown within the circle at the center of the figure. The structure of the shadow mask holding structure will be clear in FIG. 1 and FIG. 2 above. Even if vibrations are applied to this cathode ray tube from the outside, the shadow mask will hardly vibrate unless the vibration is too severe, and even if vibrations with large amplitude occur due to a large impact, the vibrations will be immediately damped by the damper wire. In practical use, there was no noticeable color shift.

0010

[Effects of the Invention] As explained above, in the flat panel shadow mask type color cathode ray tube in which the present invention is implemented,
Using an easy-to-manufacture mask frame and shadow mask, the electron beam reliably landed on the predetermined phosphor stripes, and no color shift occurred in practical use.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a shadow mask holding structure of a color cathode ray tube according to an embodiment of the present invention, in which (a) is a top view thereof, and (b) is a cross section taken along the line AA' (vertical direction) shown in (a). It is a diagram.

[Figure 2] Figure 2 is a diagram for explaining how to attach the damper wire, etc. If you look at Figures (a), (b), (c), and (d) in order, you can see that the damper wire is in close contact with the shadow mask and its front and back surfaces. It is a diagram that allows you to understand how to tension the damper wire by applying tension and the relationship between the damper wire and the shadow mask.

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

FIG. 4 is a schematic cross-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 shadow mask holding structure of a conventional color cathode ray tube.

[Explanation of symbols]

1...Neck part, 2...Funnel, 3...Panel,
4...Pipe body, 5...Face plate part, 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.

Claims (2)

[Claims] Claim 1: A fluorescent surface in which a group of vertical stripes of three primary color phosphors emitting light in different primary colors are repeatedly arranged horizontally on the inner surface of a flat panel; In a color cathode ray tube equipped with a shadow mask holding structure in which a shadow mask in which a group of vertical slits are arranged in parallel in the horizontal direction is held in a plane by a mask frame, the slits are arranged in close contact with the surface of the shadow mask and perpendicular to the slits. A color cathode ray tube characterized in that a shadow mask holding structure is used, in which one or more thin wires stretched with a predetermined tension in the lateral direction are arranged alternately on both sides of the shadow mask. 2. A color cathode ray tube according to claim 1, wherein the thin wires are tungsten wires having a diameter of 15 to 25 μm and are closely spaced on each of the front and back surfaces of the shadow mask.