JP2001195996A - Magnetic shield for cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To install easily a magnetic shield for cathode ray tube to a dichroic device without bringing about deterioration of the cathode ray tube. SOLUTION: This magnetic shield 1 is installed to a frame for supporting a dichroic mask of a cathode ray tube of it's using, and comprises contacting pieces 3 being contacted to the frame when being installed to the frame, rectangle panels 4 being disposed at right angles to the contacting pieces, bending pieces 11 being flexibly mounted to the rectangle panels 4. The bending pieces 11 and the contacting pieces 3 support the frame therebetween by the bending of the bending pieces 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic shield for a cathode ray tube used by being mounted in a cathode ray tube.

[0002]

2. Description of the Related Art In general, a cathode ray tube has an inner magnetic shield (Inner Magnetic Shield) to prevent the occurrence of a so-called mislanding, in which the trajectory of an electron beam is deviated from an original trajectory by being bent by an external magnetic field such as geomagnetism. S
hield; hereinafter referred to as “IMS”). The IMS is formed by molding a thin steel plate into a predetermined shape (generally, a trapezoidal pyramid), and is used by being attached to a frame supporting a color selection mask. The color selection mask is a thin plate having electron beam transmitting holes (small holes or slit holes) arranged in a pattern in order to selectively transmit an electron beam to emit a phosphor. A color selection mechanism is constituted by the selection mask and the frame supporting the selection mask.

[0003] Conventionally, the attachment of the IMS to the frame of the color selection mechanism has been performed using welding or clips. When welding is used, as shown in FIG.
The contact point between the frame 31 and the frame 32 of the color selection mechanism is fixed by spot welding 33. On the other hand, when clips are used, as shown in FIGS.
A rectangular hole-shaped clip hole 43 is previously provided in both the frame 41 and the frame 42 of the color selection mechanism.
The IMS 41 is fixed to the frame 42 of the color selection mechanism as shown in FIG. 7 by fitting the mounting clip 44 having a spring property into the clip hole 43 with the.

[0004]

However, since the conventional IMSs 31, 41 are attached to the frames 32, 42 of the color selection mechanism by welding or clips, there are the following drawbacks.

In the IMS 31 fixed by welding, welding spatter is generated at the time of welding. If the welding spatter hits the color selection mask, the color selection mask may be deformed or cut. Also, if this welding spatter falls off inside the cathode ray tube due to vibration or the like and becomes metallic dust, it adheres to the high voltage part and causes a breakdown voltage failure due to discharge, or adheres to the color selection mask or phosphor to block the electron beam. As a result, the quality of the cathode ray tube may be deteriorated. Furthermore, in order to perform high-quality welding, it is necessary to set up advanced and complicated conditions due to differences in the plate thickness, material, and the like of the IMS 31 and the frame 32. Will be.

Also, an IMS 4 fixed by a clip
1, the clip hole 43 is also provided in the frame 42 of the color selection mechanism.
It is necessary to process the color, and the processing may cause a decrease in the strength of the color selection mechanism and deterioration of the vibration resistance characteristics. For example, there is a possibility that the color selection mask is shaken by vibration from the outside and the color reproducibility is deteriorated. There is. Furthermore, clip hole 4
Since 3 is formed by sheet metal processing, burrs and burrs are generated at the time of processing. However, when the burrs and burrs are rubbed with the mounting clip 44 due to vibration or the like and fall off inside the cathode ray tube and become metal dust, the above-described case occurs. As in the case of welding spatter, it is conceivable that the quality of the cathode ray tube is reduced. In addition, since the mounting clip 44 is required, the cost of the apparatus increases due to an increase in the number of components.

Accordingly, the present invention does not cause deterioration in the quality of the cathode ray tube due to welding spatter, metal dust, or the like, or a decrease in the strength of the color selection mechanism, and can be extremely easily attached to the frame of the color selection mechanism. An object of the present invention is to provide a magnetic shield for a cathode ray tube.

[0008]

SUMMARY OF THE INVENTION The present invention is a magnetic shield for a cathode ray tube devised to achieve the above object, which is used by being attached to a frame supporting a color selection mask of the cathode ray tube, An abutting plate that abuts against the frame by being attached to the frame, an orthogonal plate disposed so as to be substantially orthogonal to the abutting plate, and a foldable bending piece provided on the orthogonal plate; At least a part of the bent piece and the contact plate are configured to sandwich the frame by bending the piece.

According to the magnetic shield for a cathode ray tube having the above-described structure, if the bent piece is bent in a state where the contact plate abuts against the frame, the frame is sandwiched between at least a part of the bent piece and the contact plate. . That is, if a very simple operation of bending the bent piece is performed, the cathode ray tube magnetic shield and the frame are fixed to each other.
Moreover, since the fixing is performed by the sandwiching, welding spatter and the like are not scattered, and the strength of the frame is not reduced due to the fixing because drilling or the like on the frame is unnecessary.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetic shield (IMS) for a cathode ray tube according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of an embodiment of an IMS according to the present invention.

As shown in FIG. 1A, the I of this embodiment
The MS 1 is formed by molding a thin steel plate, and has a shield portion 2 having a substantially trapezoidal pyramid shape along the emission direction (A direction in the figure) of the electron beam and a contact plate 3 substantially orthogonal to the emission direction.
And an orthogonal plate 4 arranged substantially orthogonal to the contact plate 3
It is composed of

Among these, the orthogonal plates 4 are arranged at four corners of the IMS 1 and each have a corner 4a bent at a substantially right angle. That is, the corners 4 of each orthogonal plate 4
a constitutes the four corners of the IMS 1. These four corners are formed in accordance with the shape and size of the frame of the color selection mechanism to which the IMS 1 is attached, as will be described in detail later.

An IMS fixing part 10 for fixing the IMS 1 to the frame of the color selection mechanism is provided on each orthogonal plate 4.
One by one. That is, the IMS fixing unit 10
Are arranged at a total of four locations facing each other. However, the installation location and the number of installations of the IMS fixing unit 10 may be appropriately determined according to the size of the IMS 1, the structure of the color selection mechanism, and the like. Therefore, the installation locations and the number of installations are not limited to the four locations described above. However, in consideration of the fixation of the IMS 1, the installation locations and at least two or more locations are arranged to face each other. Is preferred.

Here, the IMS fixing unit 10 will be described in detail. The IMS fixing part 10 includes a bent piece 11 and two return preventing pieces 12, as shown in FIG. 1B. Note that these are all formed in accordance with the shape and size of the frame of the color selection mechanism to which the IMS 1 is attached, as described in detail later.

As will be described later in detail, the bent piece 11 is for holding the frame of the color selection mechanism between the bent piece 11 and the contact plate 3 by bending the bent piece 11. Therefore, the bent piece 11
Is formed by pressing one side (hereinafter, this side is referred to as a "bending line") 11a except for the punched hole 11b, and can be bent from the bending line 11a. I have. The other side excluding the bending line 11a is formed in a substantially hook shape, and a side for holding a frame of the color selection mechanism located at the tip thereof (hereinafter, this side is referred to as a “frame holding side”). ) 11c are disposed substantially parallel to the contact plate 3. On the other hand, the bending line 11a is arranged substantially perpendicularly to the contact plate 3 so as to be along the emission direction of the electron beam. In addition, it is preferable to provide a hole 11d on the bending line 11a in order to facilitate bending of the bending piece 11.

As will be described in detail later, the return preventing piece 12 is for locking the bent piece 11 already bent by the bending thereof. Therefore, like the bent piece 11, the return prevention piece 12 is formed to be bendable from the bent line 12b by pressing the punched holes 11b and 12a. However, the return prevention piece 12 is disposed at a position where the two return prevention pieces 12 sandwich the bending line 11a. Each of them is formed such that its length (dimension B in the drawing) is larger than its width (dimension C in the drawing).

Next, the attachment of the IMS 1 configured as described above to the color selection mechanism will be described. FIG. 2 is a perspective view showing a specific example of an attached state of the IMS according to the present invention, and FIGS. 3 and 4 are explanatory views showing the main parts thereof in detail.

Here, first, the color selection mechanism to which the IMS 1 of the present embodiment is attached will be briefly described. FIG.
As shown in FIG. 5, a color selection mechanism 20 includes a thin plate-shaped color selection mask 21 having electron beam transmitting holes arranged in a pattern.
A frame 22 on which the color selection mask 21 is stretched;
A spring holder 23 and a spring 24 for mounting these in a cathode ray tube are provided. The frame 22 includes two A members 22a made of a metal rod formed in an L-shaped cross section, and these A members 22a.
And a B-member 22b made of a solid or hollow square member spanned over both ends of the member 22a. That is, the frame 22 is formed by joining the A member 22a and the B member 22b in a rectangular frame shape. In addition,
Each of the A member 22a and the B member 22b is made of stainless steel or the like, and each is joined by arc welding or the like.

When attaching the IMS 1 to the color selection mechanism 20, the opposite side of the color selection mask 21,
That is, four corners formed by the orthogonal plate 4 of the IMS 1 are fitted to the B member 22b from the side where the B member 22b of the frame 22 projects. At this time, the four corners are formed according to the shape and size of the frame 22 of the color selection mechanism 20. Therefore, the IMS
1 is positioned in a direction substantially perpendicular to the emission direction of the electron beam (the direction D and the direction E in the figure) by fitting to the B member 22b.

When the contact plate 3 constituting the IMS 1 is set in a state of abutting against the B member 22 b of the color selection mechanism 20, the IMS 1 is fixed to the color selection mechanism 20 by the IMS fixing unit 10. The fixing by the IMS fixing unit 10 is performed as follows.

When the contact plate 3 of the IMS 1 is
As shown in FIG. 3A, first, the bent piece 11 of the IMS fixing part 10 is substantially 90
° bend (see arrow F in the figure). This bending is performed manually or automatically by an operator or an assembling apparatus for manufacturing a cathode ray tube. And the bent piece 11
Is folded, the B member 22 of the color selection mechanism 20
As shown in FIG. 3 (b), b is held between the frame holding side 11 c of the bent piece 11 and the contact plate 3. That is, the IMS 1 is fixed to the frame 22 of the color selection mechanism 20 by sandwiching the B member 22 b between the bent piece 11 and the contact plate 3.

Thereafter, in the IMS fixing part 10, the two return preventing pieces 12 are bent. That is, as shown in FIG.
It is bent approximately 90 ° along the member 22b (see arrow H in the figure). This bending is also performed manually or automatically by an operator or assembling apparatus for manufacturing a cathode ray tube. As a result, the two return prevention pieces 1
4, as shown in FIG. 4 (b), the bent piece 11 is engaged with the bent piece 11 so as to sandwich the frame holding side 11 c of the bent piece 11, and the bent piece 1 already bent.
1 is prevented from being deformed and coming off the B member 22b.

By performing such a bending process on all of the IMS fixing portions 10 provided on each of the orthogonal plates 4 of the IMS 1, the IMS 1 is mounted on the frame 22 of the color selection mechanism 20.
It will be attached to.

As described above, the IMS 1 according to the present embodiment
According to the first aspect of the present invention, if the bent piece 11 is bent in a state where the contact plate 3 abuts against the B member 22b, the frame holding side 11c of the bent piece 11 and the contact plate 3 Since the B member 22b is configured to be clamped, the frame 2 of the color selection mechanism 20 can be formed by an extremely simple operation of bending the bending piece 11.
2 can be mounted. Therefore, this IMS
According to 1, the cathode ray tube can be attached to the frame 22 of the color selection mechanism 20 very easily without causing deterioration of the quality of the cathode ray tube due to welding spatter, metal dust, or the like, or reduction in the strength of the color selection mechanism 20.

That is, in the IMS 1 according to the present embodiment, unlike the case of attaching and mounting by, for example, welding, the deformation of the color selection mask 21 and the deterioration of the quality of the cathode ray tube due to welding spatter do not occur. . Furthermore, I
Even if the thickness and material of the MS1 and the frame 22 are different,
Since it is only necessary to bend the bent piece 11,
As in the case of welding, it is not necessary to set complicated and advanced conditions, and quick work can be easily realized. Further, unlike the case of attaching and mounting with a clip, for example, there is no need to process a separate component such as a clip or a clip hole, so that the number of components can be reduced, and the cost of the apparatus can be easily reduced. Furthermore, in addition to the fact that the strength of the color selection mechanism 20 is not reduced, burrs and burrs generated when processing the clip holes do not become metal dust.
There is no fear that the quality of the cathode ray tube will be reduced. In addition, it is possible to prevent the color selection mechanism 20 from being damaged due to dropping of the clip during operation.

Further, if the IMS 1 of the present embodiment is used, the color selection mechanism 20 can be mounted on a device having substantially the same configuration as that in the case of mounting by welding, for example. That is, since the color selection mechanism 20 does not require any change from the conventional structure, its introduction (application to a cathode ray tube manufacturing process) is very easy.

In the IMS 1 according to the present embodiment, as in the second aspect of the present invention, the bending line 11a for bending the bending piece 11 is arranged in a direction substantially perpendicular to the contact plate 3. I have. Therefore, sufficient strength can be ensured in the direction in which the bent member 11 clamps the B member 22b. That is, when the IMS 1 is mounted and mounted on the frame 22 of the color selection mechanism 20, the mounting can be reliably and firmly performed.

In the IMS 1 according to the present embodiment, if the return preventing piece 12 is bent after the bending piece 11 is bent, the return preventing piece 12 is bent.
Is configured to be locked with the bent piece 11 after bending, it is possible to prevent the bent piece 11 from being deformed and coming off the B member 22b. That is, the provision of the return preventing piece 12 enables the color selection mechanism 20 to be more securely and firmly attached to the frame 22.

The bent piece 11 and the return prevention piece 1
2 is not limited to the shape described in the present embodiment. That is, the bent piece 11 and the return prevention piece 1
As long as at least a part of the pinch 2 clamps the frame 22 or locks the bent piece 11 and satisfies a sufficient strength for the pinching or locking, the shape does not need to be particularly defined, and the shape is arbitrary. It can be formed.

[0030]

As described above, the magnetic shield for a cathode ray tube according to the present invention is constructed such that the frame of the color selection mechanism is sandwiched between the bent piece and the contact plate, so that the bent piece is bent. With this very simple operation, the color selection mechanism can be fixed to the frame. Moreover,
Since the fixing is performed by the sandwiching, welding spatter and the like are not scattered, and the strength of the frame is not reduced because the fixing is not required because drilling or the like is not required. Therefore, according to the magnetic shield for a cathode ray tube, the quality of the cathode ray tube is not degraded due to welding spatter, metal dust, or the like, or the strength of the color selection mechanism is reduced. it can.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a magnetic shield for a cathode ray tube according to the present invention, wherein (a) is a perspective view showing the whole thereof, and (b) is an enlarged view showing a main part thereof.

FIG. 2 is a perspective view showing a specific example of a state where the magnetic shield for a cathode ray tube of FIG. 1 is attached to a color selection mechanism.

FIGS. 3A and 3B are explanatory views (part 1) showing in detail a main part of a state where the magnetic shield for a cathode ray tube of FIG. 1 is attached to a color selection mechanism, (a) is a perspective view thereof, and (b) is a G arrow thereof. FIG.

FIGS. 4A and 4B are explanatory views (part 2) showing in detail a main part of a state where the magnetic shield for a cathode ray tube of FIG. 1 is attached to a color selection mechanism, (a) is a perspective view thereof, and (b) is an arrow I thereof. FIG.

FIG. 5 is a perspective view showing an example of a conventional magnetic shield for a cathode ray tube attached to a color selection mechanism.

FIG. 6 is an explanatory view showing a configuration for attaching another example of a conventional magnetic shield for a cathode ray tube to a color selection mechanism;
(A) is a diagram showing a clip hole provided in the frame of the color selection mechanism, (b) is a diagram showing a mounting clip, (c)
FIG. 4 is a view showing a main part of a state where the magnetic shield for a cathode ray tube and a frame of a color selection mechanism using the mounting clips are mounted on the frame.

FIG. 7 is a perspective view showing the whole of a state where the magnetic shield for a cathode ray tube of FIG. 6 is attached to a color selection mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... IMS (Internal magnetic shield), 3 ... Contact plate, 4 ... Orthogonal plate, 10 ... IMS fixing part, 11 ... Bending piece, 12 ...
Return prevention piece

Claims (3)

[Claims] 1. A magnetic shield for a cathode ray tube used by being attached to a frame that supports a color selection mask of a cathode ray tube, wherein the contact plate abuts against the frame when attached to the frame, An orthogonal plate arranged so as to be orthogonal, and a foldable bent piece provided on the orthogonal plate, wherein at least a part of the bent piece and the abutting plate form the frame by bending the bent piece. A magnetic shield for a cathode ray tube, wherein the magnetic shield is configured to be sandwiched. 2. The magnetic shield for a cathode ray tube according to claim 1, wherein a bending axis at the time of bending the bent piece is disposed substantially perpendicular to the contact plate. 3. The orthogonal plate further includes a return-preventing piece provided so as to be foldable separately from the bent piece, and the bent piece after at least a part of the return-preventing piece is bent by bending the return-preventive piece. 3. The magnetic shield for a cathode ray tube according to claim 2, wherein the magnetic shield is configured to be locked.