JPH05260496A - Degaussing coil - Google Patents

Abstract

PURPOSE:To provide a degaussing coil in which density of magnetic flux fed to a color selection means or the like being a degaussed member being a component of a cathode ray tube is comparatively large. CONSTITUTION:A curved part 34 of a degaussing coil 33 whose shape is made corresponding to a curved shape of a color selection means 11 is arranged along a wall face 8 of a panel section 6 of a cathode ray tube 1 in the direction of long side. Thus, since the curved part 34 of the degaussing coil 33 is much more closer to the color selection means 11, the magnetic flux with higher density by a prescribed degaussing current is fed to the color selection means 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degaussing coil suitable for application to a color cathode ray tube, particularly a color cathode ray tube having a three-beam single electron gun.

[0002]

2. Description of the Related Art Conventionally, in a color cathode ray tube,
A degaussing coil is provided to reduce the influence of an external magnetic field such as the earth's magnetism.

FIG. 4A shows a plan view structure of a conventional degaussing coil 3 mounted on a tube wall 2 of a cathode ray tube 1. FIG. 4B shows a side view configuration of the degaussing coil 3.

As shown in FIGS. 4A and 4B, the degaussing coil 3 has a linear portion 4 and a spectacle-shaped portion 5, of which,
The straight part 4 is on the tube wall 2 of the cathode ray tube 1 and in the panel part 6,
The spectacle-shaped portion 5 is arranged on the funnel portion 9 while being arranged along the long-side wall surface 8 of the tube surface 7. Thus, the degaussing coil 3 is arranged and fixed from the wall surface 8 of the panel portion 6 in the long side direction to the funnel portion 5. Arranging and fixing at such a position makes the color selection means (not shown) arranged in the panel portion 6 and the internal magnetic shield (not shown) arranged in the funnel portion 9 efficiently, that is, relatively. This is for degaussing with a small degaussing current. The degaussing coil 3 has a structure in which an insulating coated conductor is wound a plurality of times.

[0005]

By the way, in such a degaussing coil, the magnetic flux of higher density is supplied to the degaussed member such as the color selecting means with a smaller current at a constant number of turns. High degaussing efficiency is desired. This is to reduce power consumption and to reduce the thickness and weight of the degaussing coil.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a degaussing coil in which the density of magnetic flux supplied to a color selecting means, which is a member to be degaussed, is relatively large. To do.

[0007]

The degaussing coil of the present invention is, for example, as shown in FIG. 1, a degaussing coil for a cathode ray tube 1 provided with a color selecting means 11 having a shape curved in the direction of the long side of a tube surface 7. The coil has a curved portion 34 formed in a shape corresponding to the curved shape of the color selection means 11, and this curved portion 34 is included in the tube wall 2 of the cathode ray tube 1 and is the wall surface 8 in the long side direction.
It is arranged along.

[0008]

According to the degaussing coil of the present invention, the curving portion 34 of the degaussing coil 33 having the curving portion 34 formed in a shape corresponding to the curving shape of the color selecting means 11 is the cathode ray tube 1.
It is arranged along the wall surface 8 in the long side direction in the tube wall 2. Therefore, the curved portion 34 of the degaussing coil 33 comes closer to the color selecting means 11 or covers the color selecting means 11, so that a higher density magnetic flux is supplied to the color selecting means 11 with a constant degaussing current. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the degaussing coil of the present invention will be described below with reference to the drawings. In the drawings referred to below, those corresponding to those shown in FIGS. 4A and 4B above are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 shows the arrangement and configuration of the color selecting means 11 which is a member to be demagnetized in relation to the cathode ray tube 1.

The color selection means 11 has a frame 12. The frame 12 is composed of frame sides 13 and 14 formed by curving an L-shaped member in an arc shape, and arm portions 15 and 16 in which square members are formed in a channel shape. Frame edge 1
3 and 14 are respectively arranged vertically along the long side direction of the tube surface 7 of the cathode ray tube 1, and the arm portions 15 and 16 are respectively left and right along the short side direction of the tube surface 7 of the cathode ray tube 1. It is distributed.

A grid member 17 is fixed by welding between the front end faces of the frame sides 13 and 14. The lattice member 17 is called an aperture grill,
A large number of slits 18 extending in the vertical direction (short side direction) of the tube surface 7 are formed.

3 corresponding to red, blue, and green emitted from the electron gun 20 arranged in the neck portion 19 of the cathode ray tube 1.
The electron beams of the book are incident on the slits 18 of the color selection means 11 at different angles, and pass through the slits 18 to land on the corresponding red, blue, and green phosphors of the color phosphor screen 21. It has become. The landing of the electron beam causes each of the phosphors to emit light, and a color reproduced image is obtained on the tube surface 7.

Here, the electron gun 20 has a so-called three-beam single electron gun configuration in which three cathodes for emitting electron beams are arranged inline in the single electron gun. In the electron gun 20 of this three-beam single electron gun, the electron beams emitted from the three cathodes are made to intersect at the center of one main lens, and then the beams scattered in three directions are electrostatically deflected. After being refracted by a plate (not shown),
The color phosphor screen 2 is passed through the slit 18 of the color selection means 11.
It is designed to converge on 1.

A cathode ray tube 1 having such an electron gun 20.
The tube surface 7 and the color selection means 11 are basically formed in a configuration curved into a cylindrical side surface. An electron lens (not shown) is provided between the electron gun 20 and the color selection means 11.
When inserted, the tube surface 7 and the color selection means 11 are formed to have a curved cross-section even though they are not exactly cylindrical side surfaces.

FIG. 1A shows a plan view configuration of the degaussing coil 33 according to this embodiment mounted on the tube wall 2 of the cathode ray tube 1 having the color selecting means 11 as shown in FIG.
FIG. 1B shows a side view configuration of the degaussing coil 33.

As shown in FIGS. 1A and 1B, the degaussing coil 33 according to this embodiment has a spectacle-shaped portion 5 and a curved portion 34 which replaces the straight portion 4 (see FIG. 4A).
The curved portion 34 is arranged on the tube wall 2 of the cathode ray tube 1, in the panel portion 6, and along the wall surface 8 in the long side direction of the tube surface 7.
On the other hand, the spectacle-shaped portion 5 is arranged on the funnel portion 9 as described in the section of the related art.

In this way, the degaussing coil 34 is arranged and fixed from the wall surface 8 in the long side direction of the panel portion 6 to the funnel portion 9. In this case, the bending portion 34 is
It is arranged along the grid member 17 that constitutes the color selection unit 11. In this case, the bending portion 34 of the degaussing coil 33 is
Compared with the conventional technique, it is closer to the frame sides 13 and 14 (see FIG. 2) forming the color selecting unit 11. In addition, when the curved portion 34 is arranged in front of the lattice member 17, that is, on the tube surface 7 side as shown in FIG. 1, the color selection unit 11 is substantially covered.

With this arrangement, the degaussing coil 33 can supply a higher density magnetic flux to the color selecting means 11 with a constant degaussing current (damping oscillating current).

FIG. 3 shows a method for measuring the amount of displacement of the bright spots 41 to 46 on the tube surface 7 due to the difference in the orientation of the cathode ray tube 1. In FIG. 3, an arrow H indicates the direction of a uniform magnetic field (which may be a magnetic field corresponding to the earth's magnetism or a magnetic field due to the earth's magnetism), and the cathode ray tube 1 is arranged so that the tube axis is orthogonal to the axis 47 orthogonal to this magnetic field H. (In this measurement example, a 34-inch cathode ray tube) is arranged. Therefore, first, after supplying a constant degaussing current to the degaussing coil 33, bright points 41 and 42 are displayed at the upper and lower ends of the center of the tube surface 7 of the cathode ray tube 1 in the long side direction, and the upper and lower ends of the short side direction are vertically moved. Bright points 43 to 46 are displayed at the edges.

In this state, the amount of displacement of each of the bright spots 41 to 46 when the cathode ray tube 1 is rotated once in the direction of arrow P (horizontal direction) with the shaft 47 as the central axis of rotation is measured. The measurement results are shown in Table 1. In addition, Table 1 also shows the amount of displacement of the cathode ray tube 1 in which the degaussing coil 3 according to the related art, which is similarly measured, is mounted.

[0022]

[Table 1]

In Table 1, the unit of displacement is [μ
m _pp ]. The displacement amount in the “four corners” column is the average displacement amount of the four bright points 43 to 46, and the displacement amount in the “center” column is the average displacement amount of the two bright points 41, 42.

As can be seen from Table 1, in the "four corners", the amount of displacement by the degaussing coil 33 according to the present embodiment is reduced by 12 μm _pp compared with the degaussing coil 3 of the conventional example, which is improved by about 14%. There is. Also, in the "center" part,
Similarly, the displacement amount is reduced by 4 μm _pp , which is improved by about 4%. By improving the displacement in this way,
The electron beam landing described above becomes more accurate,
Color purity is improved.

As described above, in the above-described embodiment, the demagnetizing coil 33 is provided with the curved portion 34 having a shape corresponding to the curved shape of the color selecting means 11, and the curved portion 34 is formed.
On the tube wall 2 of the cathode ray tube 1, in the panel portion 6, and along the wall surface 8 in the long side direction. Therefore, the curved portion 34 of the degaussing coil 33 comes closer to the color selecting means 11,
Alternatively, since the color selecting means 11 is covered, a higher density magnetic flux can be supplied to the color selecting means 11 with a constant degaussing current. Therefore, the so-called demagnetization efficiency becomes relatively high. Therefore, when compared with the same degaussing current, it is possible to reduce power consumption and thin and lighten the degaussing coil.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0027]

As described above, according to the degaussing coil of the present invention, the curving portion of the degaussing coil having the curving portion formed in a shape corresponding to the curving shape of the color selecting means,
It is arranged along the wall surface in the long side direction in the tube wall of the cathode ray tube. Therefore, since the curved portion of the degaussing coil is closer to the color selecting means or covers the color selecting means, it is possible to supply a higher density magnetic flux to the color selecting means with a constant degaussing current. The effect is obtained.

Therefore, it is possible to obtain an effect that the amount of displacement of the bright spot due to the geomagnetism of the cathode ray tube demagnetized by the degaussing coil of the present invention is relatively small. .

[Brief description of drawings]

FIG. 1A is a plan view showing a configuration of a cathode ray tube equipped with an embodiment of a degaussing coil of the present invention. B is a side view of FIG. 1A.

FIG. 2 is a perspective view showing a configuration of a color selecting unit arranged in a cathode ray tube.

FIG. 3 is a diagram for explaining a method for measuring a displacement amount of a bright spot according to an effect of an example of the degaussing coil according to the present invention.

FIG. 4A is a plan view showing the structure of a cathode ray tube having a conventional degaussing coil attached thereto. 4B is a side view of FIG. 4A.

[Explanation of symbols]

 1 Cathode Ray Tube 6 Panel Section 7 Tube Surface 8 Wall Surface 11 Color Selection Means 33 Degaussing Coil 34 Curved Section

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[Procedure amendment]

[Submission date] October 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a color cathode ray tube, especially
The present invention relates to a degaussing coil suitable for being applied to a color cathode ray tube having an aperture grill .

Claims (1)

[Claims] 1. A degaussing coil for a cathode ray tube comprising a color selection means having a shape curved along the long side of the tube surface, the degaussing coil having a curved portion formed in a shape corresponding to the curved shape of the color selection means. The degaussing coil is characterized in that the curved portion is arranged along the long side wall surface in the tube wall of the cathode ray tube.