JPH09180645A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the coating state of phosphors, prevent luminance irregularities, and improve color purity on the whole fluorescent screen surface of a glass panel by increasing the transmittance of a shadow mask toward both ends in the horizontal direction from the minor axis of the shadow mask. SOLUTION: Multiple slot holes 13 are formed at the prescribed pitch on a shadow mask 9. The width of the openings of the slot holes 13 is changed so that the transmittance of the slot holes 13 is made higher by substantially 4-10% toward both ends in the horizontal direction from the minor axis of the shadow mask 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube.

[0002]

2. Description of the Related Art A shadow mask for a color cathode ray tube is manufactured by forming a plurality of holes at a predetermined pitch by using a photoetching method. The electron beam passes through the holes in the shadow mask and illuminates the phosphor on the phosphor screen surface of the glass panel. At this time, since the electron beam passing through the hole of the shadow mask has a large deflection angle especially around the shadow mask, it may be cut by the opening wall of the hole and the phosphor may not be sufficiently irradiated. Therefore, the holes of the shadow mask are generally formed such that the panel side opening is wider than the electron gun side opening (Japanese Patent Laid-Open No. 63-308849).

FIG. 5 is an enlarged sectional view of a shadow mask used in a color cathode ray tube in the prior art.
(A), (b) is sectional drawing of the center of a shadow mask, and both ends of a horizontal direction, respectively. As shown in FIG. 5, the shadow mask 15 has a plurality of slot holes 16 at a predetermined pitch.
Are formed. Each slot hole 16 is formed so that the panel side opening 17 is larger than the electron gun side opening 18. The width of the electron gun side opening 18 is set to be substantially constant over the entire surface of the shadow mask 15. In addition, the width of the panel side opening 17 is equal to that of the shadow mask 1.
It is set so that the periphery of the center of 5 becomes larger. Particularly, in the peripheral portion of the shadow mask 15, the width of the opening is widened as the panel side openings 17 of the adjacent slot holes 16 are connected (FIG. 5B). By adopting such a configuration, the electron beam is not cut by the opening wall, and the shadow mask 15
In the above, the ratio of the area of the slot hole to the area of the region surrounded by one pitch in each of the horizontal and vertical directions (hereinafter referred to as “hole transmittance”) is substantially constant over the entire surface of the shadow mask 15.

[0004]

Recently, development of an ultra-high-definition color cathode ray tube in which a face screen surface of a glass panel is flat and a thin plate / fine pitch shadow mask is stretched and supported on a frame in a flat state is in progress. Has been. This shadow mask is about 1/5 of the conventional shadow mask
Since the plate thickness is extremely thin, the tip of the tapered portion of the slot hole formed by the etching method has a remarkable acute angle in the above-described conventional configuration, and the rigidity is insufficient, so that the tip is easily damaged, and sufficient hole accuracy is ensured. I can't. In addition, since the shadow mask is stretched on the frame under tension, if the openings of the shadow mask are connected, stress concentrates when the shadow mask is stretched and plastic deformation occurs. The mask may be torn. Further, even if the opening can be formed wider as the adjacent openings on the panel side are connected to each other without damaging the tapered end of the slot hole, in the case of a shadow mask for an ultra-high-definition color cathode ray tube, As the pitch of the slot holes becomes finer, the width of the phosphor applied to the phosphor screen surface of the glass panel becomes narrower, which makes it difficult to apply the phosphor. In addition to this,
In the case of a glass panel whose face screen surface is almost flat, the distance at which the exposure light reaches the fluorescent screen surface is longer near both ends of the fluorescent screen surface in the horizontal direction. Such a phenomenon occurs that the width of the phosphor becomes extremely narrow, or the coating state of the phosphor becomes incomplete and the phosphor peels off. This means that even if the hole transmittance of the shadow mask is almost constant over the entire surface as in the conventional case, the phosphor on the surface of the phosphor screen cannot be applied so that the brightness becomes constant.

The present invention has been made in order to solve the above-mentioned problems in the prior art, and in the entire fluorescent screen surface of the glass panel, the phosphor coating condition is good, there is no uneven brightness, and the color purity is excellent. It is an object of the present invention to provide a color cathode ray tube.

[0006]

In order to achieve the above object, a first structure of a color cathode ray tube according to the present invention is a color cathode ray tube having a shadow mask having a plurality of slot holes arranged at a predetermined pitch. The pipe is characterized in that the hole transmittance of the shadow mask increases at a predetermined rate from the minor axis of the shadow mask toward both ends in the horizontal direction.

The second aspect of the color cathode ray tube according to the present invention is
The structure is a color cathode-ray tube provided with a shadow mask having a plurality of slot holes arranged at a predetermined pitch, the hole transmittance of the shadow mask is between the minor axis of the shadow mask and the horizontal ends. It is characterized in that the height increases at a predetermined rate from approximately the middle to both ends in the horizontal direction.

Further, in the first or second structure of the present invention, the slots are so arranged that the hole transmittance of the shadow mask is approximately 4 to 10% higher at both ends in the horizontal direction with respect to the minor axis of the shadow mask. It is preferable to change the width of the opening of the hole at a predetermined rate.

Further, in the first or second structure of the present invention, it is preferable that the plurality of slot holes are arranged at a constant pitch in the horizontal direction. Further, in the first or second configuration of the present invention, the plurality of slot holes are arranged in a horizontal direction from the minor axis of the shadow mask toward both ends in the horizontal direction at a pitch increasing at a predetermined ratio. preferable.

Further, in the first or second aspect of the present invention, it is preferable that the bridge width of the shadow mask is set to be wider in the vicinity of both ends in the horizontal direction of the shadow mask than in the center of the shadow mask.

In the first or second aspect of the present invention, it is preferable that the face screen surface of the panel is substantially flat, and the shadow mask is stretched and supported by the frame in a substantially flat state. .

According to the first aspect of the present invention, there is provided a color cathode ray tube including a shadow mask having a plurality of slot holes arranged at a predetermined pitch, wherein the hole transmittance of the shadow mask is the shadow. It is characterized in that it increases in a predetermined ratio from the short axis of the mask to both ends in the horizontal direction, so that the phosphor coating on the phosphor screen surface and the electron beam phosphor irradiation can be performed sufficiently evenly over the entire phosphor screen surface. It can be carried out.

According to the second configuration of the present invention,
A color cathode ray tube having a shadow mask having a plurality of slot holes arranged at a predetermined pitch, wherein the hole transmittance of the shadow mask is horizontal from approximately the middle of the minor axis of the shadow mask and both ends in the horizontal direction. It is characterized in that it becomes higher at a predetermined rate toward both ends in the direction, so that the phosphor coating on the phosphor screen surface and the phosphor irradiation of the electron beam can be sufficiently performed around the screen.

In the first or second structure of the present invention, slot holes are formed so that the hole transmittance of the shadow mask is approximately 4 to 10% higher at both ends in the horizontal direction with respect to the minor axis of the shadow mask. According to a preferable example in which the width of the opening is changed at a predetermined ratio, the applied state of the phosphor becomes good in the vicinity of both ends in the horizontal direction of the phosphor screen surface. Further, since the slot holes do not become too large with respect to the pitch of the slot holes, the landing margin can be secured.

According to a preferred embodiment of the first or second structure of the present invention, the bridge width of the shadow mask is set to be wider in the vicinity of both ends in the horizontal direction of the shadow mask than in the center of the shadow mask. , The strength of the shadow mask near the both ends in the horizontal direction is reduced by forming the width of the slot hole of the shadow mask to be wide at both ends in the horizontal direction, that is, the shadow mask has a high hole transmittance near the both ends in the horizontal direction. It is possible to suppress the strength deterioration and prevent the shadow mask from breaking.

In the first or second configuration of the present invention, a preferred example is that the face screen surface of the panel is substantially flat, and the shadow mask is stretched and supported by the frame in a substantially flat state. According to this, distortion of the screen image, reflection of external light, and thermal expansion of the shadow mask during operation of the color cathode ray tube can be reduced.

As described above, according to the structure of the color cathode ray tube of the present invention, the phosphor is applied well on the entire fluorescent screen surface of the glass panel, and there is no uneven brightness.
A color cathode ray tube having excellent color purity can be realized.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples. <First Embodiment> FIG. 1 is a sectional view showing a first embodiment of a color cathode ray tube according to the present invention. As shown in FIG.
The color cathode ray tube 1 includes a funnel 6 having an electron gun (not shown) and a glass panel 2 connected to the funnel 6 and having a flat face screen surface 3. A frame 7 is detachably attached to the glass panel 2. Here, the frame 7 is supported in a positioned state by the panel pin 5 inside the glass panel 2 and the spring 8 welded to the outside of the frame 7. Shadow mask 9 on frame 7
Are stretch-welded, and a plurality of slot holes 13 are arranged in the shadow mask 9 at a predetermined pitch. On the inside of the face screen surface 3 of the glass panel 2, a phosphor is applied to form a fluorescent screen surface 4. An electron beam 10 emitted from an electron gun in the funnel 6.
Passes through the slot holes 13 of the shadow mask 9 and illuminates the fluorescent screen surface 4 of the glass panel 2.

FIG. 2 shows a first color cathode ray tube according to the present invention.
FIG. 3A is an enlarged cross-sectional view showing a shadow mask used in the embodiment of FIGS. 3A and 3B, and FIGS. 3A and 3B are cross-sectional views of the center and both ends in the horizontal direction of the shadow mask, respectively. As shown in FIG.
In the shadow mask 9, a plurality of slot holes 13 are horizontal,
They are arranged at a substantially constant pitch in the vertical direction. Regarding each slot hole 13, the panel side opening 11 is the electron gun side opening 1
It is formed to be wider than 2. The widths of the panel-side opening 11 and the electron gun-side opening 12 increase at a predetermined ratio from the minor axis of the shadow mask 9 toward both ends in the horizontal direction. Therefore, the hole transmittance of the shadow mask 9 increases at a predetermined rate from the minor axis of the shadow mask 9 toward both ends in the horizontal direction. Here, the minor axis of the shadow mask is the axis connecting the midpoints of the two long sides of the shadow mask. Further, the horizontal direction is a direction parallel to the long side of the shadow mask, and the vertical direction is a direction parallel to the short axis of the shadow mask. To give a specific value regarding the shadow mask 9, in the case of a color cathode ray tube having a diagonal length of 41 cm, the minor axis length is about 240 mm, the long side length is about 320 mm, and the horizontal pitch of the slot holes 13 is about 0. 24 mm, vertical pitch of slot holes 13 is about 0.2
9 mm, panel side opening 1 of slot hole 13 in the center
The width of 1 is about 0.060 mm, the slot hole 1 in the center
The width of the electron gun side opening 12 of No. 3 is about 0.053 mm, the width of the panel side opening 11 of the slot hole 13 at both ends in the horizontal direction is about 0.070 mm, and the width of the electron gun side opening 12 of the slot hole 13 at both ends in the horizontal direction. Is about 0.056 mm.

FIG. 3 is a diagram showing the hole transmittance distribution on the entire surface of the shadow mask of FIG. As shown in FIG. 3, the hole transmittance of the shadow mask 9 increases at a predetermined rate from approximately the middle of the short axis of the shadow mask 9 and both ends in the horizontal direction, and its value is about the center of the shadow mask 9. 19%,
It is about 20% at both ends in the horizontal direction.

By adopting the above configuration,
Since the hole transmittance is high at both ends of the shadow mask 9 in the horizontal direction, the phosphor coating on the phosphor screen surface 4 and the phosphor irradiation of the electron beam can be sufficiently and uniformly performed over the entire phosphor screen surface 4. In particular, if the hole transmittance of the shadow mask 9 is increased at a predetermined ratio from approximately the midpoint between the short axis of the shadow mask 9 and both ends in the horizontal direction, the coating state of the phosphor in the vicinity of both ends in the horizontal direction of the phosphor screen surface 4 will be improved. It will be good.

In this embodiment, the horizontal pitch of the slot holes 13 of the shadow mask 9 is set to be substantially constant over the entire surface of the shadow mask 9, but the present invention is not necessarily limited to this structure, and the center of the shadow mask 9 is not limited to this. The same effect can be obtained by using a shadow mask in which the horizontal pitch increases from the edge to the periphery at a predetermined rate.

Further, in this embodiment, the hole transmittance of the shadow mask 9 is about 19 at the center of the shadow mask 9.
%, And about 20% at both ends in the horizontal direction, but it is not necessarily limited to this value. However, the shadow mask 9
When the ratio of increasing the values of the hole transmittances at both ends in the horizontal direction with respect to the hole transmittance on the short axis of is less than 4%, almost no effect is observed. If the ratio of increasing the hole transmittance values at both ends in the horizontal direction relative to the hole transmittance value on the minor axis of the shadow mask 9 is too large, the slot holes 13 are too large with respect to the pitch. , Landing margin cannot be secured. Therefore, the value of the hole transmittance at both ends in the horizontal direction is preferably about 4 to 10% higher than the value of the hole transmittance on the short axis, and the phosphor coating on the phosphor screen surface 4 and the fluorescence of the electron beam are performed. Body irradiation can be sufficiently performed around the screen.

<Second Embodiment> FIG. 4 is an enlarged front view showing a shadow mask used in a second embodiment of the color cathode ray tube according to the present invention. The difference from the first embodiment is that the width a of the bridge 14 of the shadow mask 9 is wider than the center of the shadow mask 9 near both ends in the horizontal direction of the shadow mask 9. Shadow mask 9 of this embodiment
Are formed by the slot holes 13, and the phosphor is applied to the phosphor screen surface 4 (see FIG. 1) in a stripe shape, so that it is not necessary to consider the beam landing deviation in the vertical direction. In this embodiment, the width a of the bridge 14 is 0.035 mm at the center of the shadow mask 9 and 0.04 mm at both ends in the horizontal direction.

By adopting the above configuration,
Strengthening the widths of the openings 11 and 12 of the slot holes 13 of the shadow mask 9 at both ends in the horizontal direction deteriorates the strength near the both ends in the horizontal direction of the shadow mask 9, that is, the hole transmittance of the shadow mask 9 near the both ends in the horizontal direction. It is possible to prevent the strength of the shadow mask from being deteriorated due to the high cost, and to prevent the shadow mask from breaking.

In this embodiment, the width a of the bridge 14 is 0.035 mm at the center of the shadow mask 9 and 0.04 mm at both ends in the horizontal direction, but the width a is not limited to this value. The width a of the bridge 14 is
Considering the etching limit of the shadow mask 9 and the improvement of the brightness of the color cathode ray tube, the thickness is preferably about 0.02 to 0.05 mm.

[0027]

As described above, according to the present invention,
It is possible to realize a color cathode ray tube in which the phosphor is applied well over the entire area of the fluorescent screen surface of the glass panel, has no uneven brightness, and has excellent color purity.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a color cathode ray tube according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a shadow mask used in the first embodiment of the color cathode ray tube according to the present invention.

FIG. 3 is a diagram showing a hole transmittance distribution on the entire surface of the shadow mask of FIG.

FIG. 4 is an enlarged front view showing a shadow mask used in a second embodiment of the color cathode ray tube according to the present invention.

FIG. 5 is an enlarged cross-sectional view showing a shadow mask in the related art.

[Explanation of symbols]

 1 Color Cathode Ray Tube 2 Glass Panel 3 Face Screen Surface 4 Fluorescent Screen Surface 5 Panel Pin 6 Funnel 7 Frame 8 Spring 9 Shadow Mask 10 Electron Beam 11 Panel Side Opening 12 Electron Gun Side Opening 13 Slot Hole 14 Bridge

Claims (7)

[Claims] 1. A color cathode ray tube comprising a shadow mask having a plurality of slot holes arranged at a predetermined pitch, wherein the hole transmittance of the shadow mask is directed from the minor axis of the shadow mask to both ends in the horizontal direction. The color cathode ray tube is characterized in that it increases at a predetermined rate. 2. A color cathode ray tube including a shadow mask having a plurality of slot holes arranged at a predetermined pitch, wherein the hole transmittance of the shadow mask is the same as the minor axis of the shadow mask and both ends in the horizontal direction. The color cathode ray tube is characterized in that the height of the color cathode ray tube increases from a substantially middle portion to both ends in the horizontal direction at a predetermined rate. 3. The hole transmittance of the shadow mask is approximately 4 to 10 at both ends in the horizontal direction with respect to the minor axis of the shadow mask.
3. The color cathode ray tube according to claim 1, wherein the width of the opening of the slot hole is changed at a predetermined rate so as to be higher. 4. The color cathode ray tube according to claim 1, wherein the plurality of slot holes are arranged horizontally at a constant pitch. 5. The color cathode ray tube according to claim 1, wherein the plurality of slot holes are arranged from the minor axis of the shadow mask in a horizontal direction at a pitch increasing toward both ends in the horizontal direction at a predetermined ratio. . 6. The color cathode ray tube according to claim 1, wherein a bridge width of the shadow mask is set wider near both ends of the shadow mask in the horizontal direction than in the center of the shadow mask. 7. The color cathode ray tube according to claim 1, wherein the face screen surface of the panel is substantially flat, and the shadow mask is stretched and supported by the frame in a substantially flat state.