JPH09265918A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the mask failure of a shadow mask, and increase the fixing strength of a magnetic, shield body against a frame when the magnetic shield body is automatically incorporated into the frame. SOLUTION: A color picture tube is provided with a bulb which is formed by successively arranging a front panel portion inner face of which a fluorescent screen is made and a neck portion inside which an electron gun is equipped, and a shadow mask 7 which is confronting arranged to the fluorescent screen with a predetermined gap, and a rectangular cylindrical frame 9 to one end side of which the shadow mask 7 is fitted and on the other side of which an approximately truncated quadrangular pyramid-like magnetic shield body 8 is supported. Support bodies 12, 13 are provided on the frame 9 so that the magnetic shield body 8 is held between the frame 9 and the support bodies 12, 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube such as a television receiver and a display, and more particularly to a structure for attaching a magnetic shield to a shadow mask frame.

[0002]

2. Description of the Related Art A conventional color picture tube includes a bulb having a front panel portion having a fluorescent surface formed on the inner surface thereof in order to reduce the influence of an external magnetic field such as the earth's magnetism on the electron beam emitted from an electron gun. A shadow mask supported on the fluorescent surface of the front panel portion at a predetermined interval, a shadow mask on one end side, and a frame supporting the magnetic shield body on the other end side are provided.

As a method capable of automating the assembling work of the magnetic shield body and the frame, Japanese Patent Laid-Open No. 4-167 is known.
Japanese Unexamined Patent Publication (Kokai) No. 337 discloses that the magnetic shield body is provided with cut-and-raised portions at a plurality of locations around the large-diameter opening, and the cut-and-raised portions are bent through small holes provided in a frame having a shadow mask. Has been done.

[0004]

However, in the above method, the magnetic shield is cut and raised from the shadow mask side and fixed to the frame having the shadow mask. When the tool comes into contact with or drops on the shadow mask, mask defects such as mask scratches and mask dents occur, and the magnetic shield body has a thin plate thickness of about 0.1 to 0.2 mm. The fixing strength between the shield body and the frame is weak, and there is a problem that the magnetic shield body is displaced from a predetermined position due to vibration or the like after being fixed to shield the electron beam or generate vibration noise.

The present invention solves the above problems and prevents a defective mask of a shadow mask when automatically assembling a magnetic shield body to a frame, and improves the fixing strength of the magnetic shield body to the frame. Is provided.

[0006]

A color picture tube of the present invention comprises a front panel portion having a fluorescent surface formed on the inner surface thereof, and a bulb having a neck portion having an electron gun therein sequentially arranged, and a bulb on the fluorescent surface. A shadow mask disposed to face each other with a predetermined interval, and a rectangular cylindrical frame for attaching the shadow mask to one end side and supporting the substantially quadrangular pyramidal magnetic shield body on the other end side, A support is provided on the frame, and the magnetic shield is held between the frame and the support.

According to this structure, the magnetic shield body is inserted from the electron gun side between the frame surface and the support body,
Since the magnetic shield body can be held on the frame, the defective mask can be prevented without the assembly tool coming into contact with or dropping on the shadow mask. Further, the magnetic shield can be firmly fixed to the frame by adjusting the gap between the frame surface and the support.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

As shown in FIG. 2, the color picture tube according to the first embodiment of the present invention includes a front panel 2 having a red, green, and blue fluorescent screen 1 formed on the inner surface thereof, a funnel portion 3, and an internal portion. A bulb 6 formed by sequentially arranging neck portions 5 having electron guns 4 arranged in-line, a shadow mask 7 facing the phosphor screen 1 at a predetermined interval, and a shadow mask 7 on one end side. Attach the magnetic shield 8 to the other end
And a frame 9 for supporting the.

The shadow mask 7 has an electron beam transmitting hole and is made of iron or iron-nickel alloy having a thickness of about 0.25 mm.

The magnetic shield 8 is made of iron or a metal having a magnetic permeability equal to or higher than that of iron, for example, low carbon aluminum killed steel, and has a large opening 8a on the shadow mask 7 side and a small diameter on the electron gun 4 side. Each of which has a substantially quadrangular pyramid shape and has an opening 8b.
Has a projecting portion 10 on a surface orthogonal to the tube axis. The magnetic shield body 8 prevents the electron beam deflected by the deflection yoke (not shown) from being affected by an external magnetic field such as geomagnetism.

As shown in FIG. 1, the frame 9 is made of a metal plate such as iron and is formed in a rectangular tube shape having a frame surface 11 orthogonal to the tube axis of the neck portion 5 on the electron gun 4 side. Further, on the frame surface 11 of the electron gun 4 in the horizontal scanning line direction (frame surfaces 11a and 11b on the opposing long sides of the frame 9), the cross section is substantially Z-shaped and the long side of the frame 9 is formed. Parallel rail-shaped supports 12 and 13 are provided, and a support spring 14 is provided on the outer surface of the rectangular tubular shape of the frame 9. Then, one end portion 9a of the frame 9 on the side of the phosphor screen 1
The shadow mask 7 is welded to the frame surface 11a, 11b of the other end 9b of the frame 9 and the support surface 12a, 1
The projecting portion 10 of the magnetic shield body 8 is inserted between the magnetic shield body 3 and 3a to hold the magnetic shield body 8. Further, the support spring 14 of the frame 9 is engaged with the support pin 15 provided on the inner surface of the valve 6 shown in FIG. 2 so that the shadow mask 7 is held at a predetermined interval with respect to the fluorescent screen 1. There is. Further, the frame surfaces 11a and 11b and the support surface 1 are arranged so that the projecting portion 10 of the magnetic shield body 8 can be easily inserted.
The gap H ₁ between the insertion openings 16 and 17 with the 2a and 13a is made larger than the clearance H ₂ other than the insertion opening.

Next, the operation of the color picture tube will be described. The color picture tube of the first embodiment of the present invention is
Since the support bodies 12 and 13 having a substantially Z-shaped cross section are provided on the frame surfaces 11a and 11b on the long side of the frame 9, the magnetic shield body 8 is held on the frame 9 and then the magnetic shield body 8 is held.
It is possible to prevent the magnetic shield body 8 from dropping from the frame 9 due to gravity.

Further, the frame surfaces 11a and 11b and the support surface 12
The magnetic shield body 8 can be held by the frame 9 by slidingly inserting the projecting portion 10 of the magnetic shield body 8 from the side surface of the frame 9 on the electron gun 4 side in the direction of the arrow between the a and 13a. Of course, the assembly tool does not come into contact with the shadow mask 7 during assembly. As a result, mask defects such as mask scratches and mask dents on the shadow mask 7 can be prevented.

Further, the frame surfaces 11a and 11b and the support surface 1
The magnetic shield body 8 can be firmly fixed to the frame 9 by adjusting the gap H ₂ between the magnetic shield body 2a and 13a.
As a result, the vibration due to the magnetic shield body 8 can be prevented, and the shielding of the electron beam by the magnetic shield body 8 can be prevented.

FIG. 3 shows a second embodiment of the present invention.
This embodiment is different from the first embodiment in that the rail-shaped supports 12 and 13 have a frame surface 11 on the short side of the frame 9.
The difference is that a stopper 17 for positioning the magnetic shield body 8 is provided under the support bodies 12 and 13 provided on the c and 11d.

According to this embodiment, the frame surfaces 11c, 11
d and the support surface 12a, 13a, the protruding portion 10 of the magnetic shield 8 from the upper surface of the frame 9 on the electron gun 4 side.
Since the magnetic shield body 8 can be held in the frame 9 by slidably inserting it in the direction of the arrow, not only can automated assembly be performed, but the assembly tool does not come into contact with the shadow mask 7 during assembly. As a result, mask defects such as mask scratches and mask dents on the shadow mask 7 can be prevented. Further, the rail-shaped support bodies 12 and 13 are shorter in length than those in the first embodiment, and economical when the magnetic shield body 8 is automatically assembled, the moving distance of the magnetic shield body 8 is shortened. It has a great effect.

FIG. 4 shows a third embodiment of the present invention,
This embodiment is different from the above-described first and second embodiments in that at least one side of the frame 9 is provided with a protrusion 18 such as a semicircle or a triangle, and the projecting portion 10 of the magnetic shield body 8 is supported by the support body 12 (support body). The difference is that the magnetic shield body 8 is positioned by being sandwiched between the body 13) and the protrusion 18.

According to this embodiment, for example, in the first embodiment, when the semicircular protrusion 18 is provided on the frame surface 11a on the support body 12 side in FIG. 1, the projecting portion 10 of the magnetic shield body 8 is provided. Since the magnetic shield body 8 can be easily slid in the direction of the arrow and the distance L ₁₀ between the support body 12 and the protrusion 18 is short, the magnetic shield body 8 can be positioned in the vertical direction. The accuracy is improved, and the movement of the magnetic shield body 8 due to the vertical vibration can be prevented.

In the first and second embodiments described above, in order to easily attach the magnetic shield 8 to the frame 9 and firmly fix it to the frame 9, the supports 12, 1 are used.
The length L _{4 of} 3 is preferably 80% to 100% of the length of the side of the frame 9 to which the supports 12 and 13 are attached. Further, not limited to the above embodiment, a plurality of short rails may be arranged side by side to form the supports 12 and 13, and the supports 12 and 13 are provided on the outer surface of the frame 9 instead of the frame surface 11 of the frame 9. May be. Further, the above-mentioned embodiments may be combined together.

Next, a specific example of the present invention will be described. The 25-inch color picture tube of the embodiment of the present invention has the configuration shown in FIGS. 1 and 2, and the length L ₁ of the long side of the frame 9 is 481.
mm, the length L ₂ of the short side is 366 mm, the width L ₃ of the frame surface 11 is 50 mm, and the length L ₄ of the supports 12 and 13 is 476 m.
m, L ₅ of the protruding portion is 7 mm, the support 12 and the support 13
The distance L ₆ 360 mm, the frame surface 11a, 11b and 0.25mm clearance of H ₂ and the support 12, the gap H ₁ of the insertion opening and 0.5mm between the overhanging portion 10 of the magnetic shield 8 Long side length L ₇ is 476 mm, short side length L ₈
Is 355 mm, the length L ₉ of the overhanging portion 10 is 10 mm,
A plate having a plate thickness t of 0.25 mm was used.

Then, in 50 samples, after automatically assembling the magnetic shield body 8 on the bulb having the shadow mask 7 and the frame 9, the mask defect rate of the mask scratches and the mask dents was examined, and then the assembled magnetic field was examined. The unit of the shield body 8 is vibrated at an acceleration of about 5 G for 30 minutes, and the vibration sound before and after the vibration (initial state) and the magnetic shield body 8 are applied.
The position shift of was investigated.

The mask defect rate was 0/50, and the vibration noise and the positional deviation of the magnetic shield body 8 did not change with time from the initial state.
There was no problem with zero.

[0024]

As described above, according to the present invention, when a magnetic shield body is automatically assembled to a frame, a mask defect of a shadow mask is prevented and a fixing strength of the magnetic shield body to the frame is improved. You can get a tube.

[Brief description of drawings]

FIG. 1 is a perspective view showing a frame portion of a color picture tube which is a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of the same picture tube device.

FIG. 3 is a perspective view showing a frame portion of a color picture tube which is a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing a frame part of a color picture tube which is a third embodiment of the present invention.

[Explanation of symbols]

 1 Phosphor screen 2 Front panel 4 Electron gun 5 Neck 6 Valve 7 Shadow mask 8 Magnetic shield 9 Frame 12, 13 Support

Claims (4)

[Claims] 1. A shadow mask in which a front panel portion having a fluorescent surface formed on an inner surface thereof and a neck portion having an electron gun therein are sequentially arranged, and a shadow mask which is arranged to face the fluorescent surface at a predetermined interval. And a rectangular cylindrical frame for mounting the shadow mask on one end side and supporting the substantially quadrangular pyramid-shaped magnetic shield body on the other end side, providing a support body on the frame, and supporting the frame and the support. A color picture tube, characterized in that the magnetic shield body is held between the body and the body. 2. The color picture tube according to claim 1, wherein the support is provided on the opposite side of the frame. 3. The color picture tube according to claim 2, wherein the support is provided on the side of the electron gun in the horizontal scanning line direction. 4. The collar according to claim 1, wherein the length of the support is 80% to 100% of the length of the side of the frame to which the support is attached. Picture tube.