JPH05314919A - Internal magnetic shield with electron beam reflecting shield for color cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide an internal magnetic shield with an electron beam reflecting shield which can prevent halation (frame reflection) without increase of the number of parts, and is capable of mounting multiple internal magnetic shields. CONSTITUTION:In respective upper and lower corner metal plates 13a, 13b of an internal magnetic shield attached to a color selection mechanism of a color cathode-ray tube, respective right and left symmetric parts are bent in the nearly vertical direction so as to oppose to each other at respective upper and lower parts, thus providing bent parts 20a, 20b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a color cathode ray tube (CR
T) The present invention relates to an internal magnetic shield with an electron beam reflection shield, and more particularly to an internal magnetic shield integrated with a shield for suppressing scanning electron beam reflection in a Trinitron color CRT color selection mechanism (aperture grill: AG) frame. ..

[0002]

2. Description of the Related Art FIG. 5 shows a general trinitron color CR.
The components of T are shown.

FIG. 5 (a) shows a glass panel 1, FIG. 5 (b) shows a metal aperture grill (AG) 2 as a color selection mask, and FIG. 5 (c) shows an upper corner metal plate 3a. A metal inner magnetic shield (IMS) 3 having a lower corner metal plate 3b is shown, FIG.
The glass funnel 4 joined with the panel 1 in which S3 is set is shown. The AG2 is provided with a spring 19 for attaching the AG to the panel 1, and the funnel 4
An electron gun (gun) 6 for injecting electrons is provided at the end of the details.

[0004]

PROBLEM TO BE SOLVED BY THE INVENTION Trinitron Color C
The AG, which is a color selection mechanism of the RT, is made of metal as described above, and frame reflection called halation occurs due to overscanning of the scanning electron beam.

As shown in FIG. 6, the AG 2 has a frame A member 7 attached to its upper and lower ends (not shown), an end of the frame A member 7 at the upper end of the AG mask, and an AG lower end frame A member. A frame B member 8 for joining the ends of the frame B is provided. However, as shown in FIG. 7, the scanning electron beam 9 of the CRT that hits the end surface of the frame A member 7 is reflected there and enters the AG surface.

In order to prevent such frame reflection,
In the conventional consumer tube, the frame A member 7a is used to prevent the electron beam 9 from hitting the frame as shown in FIG.
The taper portion 10 is provided on the above to suppress the reflection thereof.

However, even if the tapered portion 10 is provided on the frame member 7a, it is not sufficient to prevent the frame reflection,
In the high definition tube, as shown in FIG. 9, a thin metal plate part called an upper beam shield (UBS) 15 is welded to the frame A member 7 to prevent frame reflection. As shown in FIG. 9B in particular, the electron beam 9 is emitted from the UBS 15
This prevents reflection on the frame A member.

In the method shown in FIG. 9, since the UBS 15 is attached to the R portion of the frame A member 7, the attachment accuracy is strict and the number of steps and the number of parts are increased.

Moreover, the conventional method has a problem that only a few sheets of IMS 3 can be loaded because they are closely attached to each other as shown in FIG.

Therefore, the present invention provides an internal magnetic shield with an electron beam reflection shield, which enables halation (frame reflection) due to overscanning of a scanning electron beam without increasing the number of parts, and moreover, enables loading of a large number of internal magnetic shields. The purpose is to provide.

[0011]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned problems are solved by the upper and lower portions of the respective left and right target portions of the upper and lower corner metal plates of the inner magnetic shield attached to the color selection mechanism of the color cathode ray tube. This is solved by an internal magnetic shield with an electron beam reflection shield of a color cathode ray tube, which is provided with bent portions formed by bending in a substantially vertical direction so as to face each other.

[0012]

According to the present invention, the upper and lower corner metal plates 3 of the conventional internal magnetic shield (IMS) shown in FIG.
a and 3b, as shown in FIG.
0a, 20b are bent vertically (upper part is facing downward, lower part is facing upward) to form a bent part, and therefore, when mounted on the aperture grille (AG) 12, as shown in FIG. 2, the bent parts 20a, 20b are bent. Can function as a reflection shield for electron beams.

By providing the bent portions 20a and 20b integrally, the IMS 13 of the present invention can be efficiently loaded as shown in FIG.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a main part of an embodiment of an internal magnetic shield (IMS) with an electron beam reflection shield according to the present invention.

In FIG. 1, the internal magnetic shield 1 of the present invention is shown.
3 is the upper and lower corner metal plates 1 of the conventional internal magnetic shield
3a and 13b are bent substantially vertically so as to face each other in the vertical direction, and bent portions 20a (upper side) and 20b (lower side) are provided, and the bent portions 20a and 20b are provided in the conventional UBS so-called electron shown in FIG. Combines the function of the beam reflection shield.

FIG. 2 is a perspective view of a main part in which the internal magnetic shield 13 of this embodiment shown in FIG. 1 is attached to the AG 12. A frame A member 17 and a frame B member 18 are provided in the AG 12 as in the conventional case.

FIG. 3 is a schematic diagram showing reflection of an electron beam using the embodiment of FIG.

According to FIG. 3, the bending portion 20 of the IMS 13 is longer than the frame A member 17, and
You can see that it fulfills the function of. Reference numeral 18 is a frame B member, and 12 is an AG.

FIG. 4 is a schematic view showing a state in which the IMS according to the present invention is loaded.

As shown in FIG. 4, the IMS 13 of the present invention does not perform a close stacking overlapping with the conventional one, and the bending portion 2
When the number of sheets is 0, the sheets are loaded while supporting each other at intervals, so that it is possible to load several tens of sheets.

[0022]

As described above, according to the present invention, halation due to overscan of a scanning electron beam in a cathode ray tube (CRT) can be prevented without complicated steps and increasing the number of parts. ..

Furthermore, the internal magnetic shield (I
MS) is also advantageous in terms of loading efficiency because it can load several tens of sheets.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an internal magnetic shield (IMS) of the present invention.

FIG. 2 is a view showing the IMS of the present invention as an aperture grill (AG).
It is a perspective view attached to a mask (color selection mechanism).

FIG. 3 is a schematic diagram showing reflection of an electron beam using the IMS of the present invention.

FIG. 4 is a schematic diagram showing a state in which the IMS of the present invention is loaded.

FIG. 5 is a schematic perspective view showing components of a general Trinitron color CRT.

FIG. 6 is a partial perspective view showing a frame member of AG.

FIG. 7 is a diagram showing frame reflection.

FIG. 8 is a diagram showing frame reflection in a frame provided with a tapered portion.

FIG. 9: Upper beam shield for high definition tubes (UB
It is a figure which shows S).

FIG. 10 is a conventional internal magnetic shield stacking diagram.

[Explanation of symbols]

 1 panel 2,12 aperture grille (AG) 3,13 internal magnetic shield (IMS) 4 funnel 6 electron gun (gun) 7,7a, 17 frame A member 8,18 frame B member 9 electron beam 10 taper part 15 upper beam Shield (UBS) 19 Spring 20 Bend (UBS)

Claims (1)

[Claims] 1. A bent portion formed by bending substantially right and left symmetrical portions of upper and lower corner metal plates of an inner magnetic shield attached to a color selection mechanism of a color cathode ray tube so as to face each other at upper and lower portions. An internal magnetic shield with an electron beam reflection shield for a color cathode ray tube characterized by being provided with.