JP4144150B2 - Cathode ray tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cathode ray tube used for a television or a personal computer monitor.
[0002]
[Prior art]
FIG. 8 shows a conventional cathode ray tube such as a television or a personal computer monitor. An electron beam 22 emitted from an electron gun 21 is deflected vertically and horizontally by a deflection yoke 23 and scanned over the entire screen to reproduce an image. . At this time, as shown in FIGS. 9 and 10, an electron shield 26 is provided on the internal magnetic shield 25 in order to prevent the electron beam 22 from being reflected on the mask frame 24 and the like to generate halation, The beam 22 was shielded to take measures against halation. The arrows in FIGS. 9 and 10 indicate the direction of the magnetic field blown from the tip of the electron shield 26 or the mask frame 24.
[0003]
[Problems to be solved by the invention]
When an electron shield is provided on the internal magnetic shield as described above or an electron beam is shielded by a mask frame, a magnetic field is blown out from the tip of the electron shield or the mask frame by an external magnetic field such as geomagnetism, and the magnetic field is converted into an electron beam. Was distorted and had an adverse effect on landing. In particular, mislanding was significantly worse at the top and bottom of the screen. In particular, cathode ray tubes requiring high definition need to improve mislanding at the end of the tube surface.
[0004]
The present invention has been made in order to solve the above-mentioned problems, and provides a cathode ray tube that reduces distortion of an electron beam due to a magnetic field blown from an electron shield or a mask frame, reduces mislanding, and prevents color misregistration and color unevenness. The purpose is to provide.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the cathode ray tube of the present invention has the following characteristics.
(1) An envelope composed of at least a panel portion and a funnel portion, a shadow mask disposed opposite to a phosphor screen formed on the inner surface of the panel portion, a mask frame supporting the shadow mask, and a tube axis coaxially A cathode ray tube comprising an internal magnetic shield disposed in the funnel portion, wherein the internal magnetic shield includes an electron shield projecting inside the mask frame to shield the electron beam, and the longitudinal direction of the electron shield The cathode ray tube tube is characterized in that it has a partition portion on which a magnetic metal material is welded .
[0006]
(2) An envelope composed of at least a panel portion and a funnel portion, a shadow mask disposed opposite to a phosphor screen formed on the inner surface of the panel portion, a mask frame supporting the shadow mask, and a tube axis coaxially A cathode ray tube comprising an internal magnetic shield attached to the funnel portion and having a screen portion that is provided by welding a magnetic metal material to the mask frame.
[0007]
According to the present invention, it is possible to provide a cathode ray tube that reduces distortion of an electron beam due to a magnetic field blown from an electron shield or a mask frame, reduces mislanding, and prevents color misregistration and color unevenness.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention supports an envelope composed of at least a panel portion and a funnel portion, a shadow mask disposed opposite to a phosphor screen formed on the inner surface of the panel portion, and the shadow mask. A cathode ray tube comprising an internal magnetic shield mounted coaxially with a mask frame and a tube axis and disposed in the funnel portion, wherein the internal magnetic shield includes an electron shield that projects inside the mask frame and shields an electron beam. And a cathode ray tube characterized by having a screen portion welded and disposed in the longitudinal direction of the electron shield, and the distortion of the electron beam due to the magnetic field blown from the electron shield is reduced. To provide a cathode ray tube that reduces landing and prevents color misregistration and color unevenness It can be.
[0009]
The invention according to claim 3 of the present invention supports an envelope composed of at least a panel portion and a funnel portion, a shadow mask arranged to face a phosphor screen formed on the inner surface of the panel portion, and the shadow mask. A cathode ray tube comprising an internal magnetic shield mounted on the same axis as the mask frame and the tube axis and disposed in the funnel portion, wherein the mask frame has a partitioning portion disposed by welding a magnetic metal material. Therefore, it is possible to provide a cathode ray tube that reduces distortion of an electron beam due to a magnetic field blown from a mask frame, reduces mislanding, and prevents color misregistration and color unevenness.
[0010]
Hereinafter, a cathode ray tube according to an embodiment of the present invention will be described with reference to FIGS.
[0011]
(Embodiment 1)
FIG. 1 is a schematic diagram of a cathode ray tube according to Embodiment 1 of the present invention. This cathode ray tube includes an envelope composed of at least a panel portion 1 and a funnel portion 2, a shadow mask 4 disposed opposite to a phosphor screen 3 formed on the inner surface of the panel portion 1, and a mask frame 5 that supports the shadow mask 4. And an inner magnetic shield 6 mounted coaxially with the tube axis and disposed in the funnel portion 2, and the inner magnetic shield 6 is provided with an electron shield 8 for shielding the electron beam 7. 2 and 3 are cross-sectional views in the vicinity of the shadow mask 4 in FIG. 4 is a cross-sectional perspective view of FIG.
[0012]
The electron shield 8 is notched in the longitudinal direction of the electron shield 8 in FIG. 2 and forms a bent screen portion 9 which is bent substantially parallel to the tube axis direction. In FIG. 3, a magnetic metal is formed in the longitudinal direction of the electron shield 8. The welding screen part 10 is formed by welding the materials. As shown in FIG. 4, the longitudinal direction of the electron shield 8 here is an arrow direction in the figure, and is a direction along the side of the electron shield 8. 2 and 3 indicate the directions of the magnetic field blown out from the electron shield 8, the folding partition 9, and the welding partition 10 when an external magnetic field such as geomagnetism is applied.
[0013]
FIG. 5 shows a conventional electron shield (hereinafter referred to as ES1), a notch in the longitudinal direction of the electron shield 8 with respect to a tube axis magnetic field and a horizontal magnetic field for a 25-inch cathode ray tube, and a bend that is bent substantially parallel to the tube axis direction. When an electron shield (hereinafter referred to as ES2) provided with a screen part 9 and an electron shield (hereinafter referred to as ES3) formed by welding Fe material, which is a magnetic metal material of the same material as the electron shield, is formed. Shows the amount of mislanding at the corner of the screen.
[0014]
It can be seen that the amount of mislanding is reduced when ES2 and ES3 are used compared to ES1 with respect to the tube axis magnetic field and the horizontal magnetic field. As shown in FIG. 2 and FIG. 3, the place where the magnetic field flowing from the internal magnetic shield 6 and the mask frame 5 blows out is the folding screen portion 9 or the welding screen portion 10 of the electron shield 8 and the electron shield tip portion. 11, and the direction in which the magnetic field blows out from the bending partition 9 or the welding partition 10 of the electron shield 8 in a direction to cancel the force received from the geomagnetism of the electron beam 7.
[0015]
As a result, the amount of magnetic field blown out from the electron shield tip 11 is reduced as compared with the prior art, and the force due to the magnetic field applied to the electron beam 7 near the electron shield 8 is reduced. As a result, the amount of mislanding due to distortion of the electron beam 7 Decreased.
[0016]
It goes without saying that the same effect can be obtained even if the sizes of the internal magnetic shield and the mask change with different types of cathode ray tubes.
[0017]
(Embodiment 2)
FIG. 6 is a sectional view of the vicinity of the shadow mask of the cathode ray tube according to the second embodiment. A magnetic metal material is welded to the mask frame 12 in the longitudinal direction (the direction along the side of the mask frame) to form a welding screen portion 13. The arrow direction in FIG. 6 indicates the direction of the magnetic field blown out from the mask frame 12 when an external magnetic field such as geomagnetism is applied.
[0018]
In FIG. 7, a conventional mask frame (hereinafter referred to as MF1) and a magnetic metal material, Fe, are welded in the longitudinal direction of the mask frame 12 with respect to the tube axis magnetic field and horizontal magnetic field for the 25-inch cathode ray tube to form a welding screen portion 13. The mislanding amount at the screen corner when the mask frame (hereinafter referred to as MF2) is used is shown.
[0019]
It can be seen that the mislanding amount is reduced by using MF2 compared to MF1 for the tube axis magnetic field and the horizontal magnetic field. As shown in FIG. 6, the place where the magnetic field that flows from the internal magnetic shield 6 and the mask frame 12 blows out is distributed to the welding screen portion 13 of the mask frame 12 and the mask frame front end portion 14. The direction in which the magnetic field blows out also from the welding screen portion 13 of the mask frame 12 in a direction that cancels out the force received from the geomagnetism of the electron beam 7. As a result, the amount of magnetic field blown from the mask frame tip 14 is reduced compared to the conventional case, and the force due to the magnetic field applied to the electron beam 7 near the mask frame 12 is reduced. As a result, the amount of mislanding due to distortion of the electron beam 7 Decreased.
[0020]
It goes without saying that the same effect can be obtained even if the sizes of the internal magnetic shield and the mask change with different types of cathode ray tubes.
[0021]
【The invention's effect】
As described above, according to the first embodiment of the present invention, the electron shield is provided with a bent partition portion that is notched and bent or a welded partition portion that is welded with a magnetic metal material. The location where the magnetic field is blown out is distributed between the electron shield folding screen or welding screen and the electron shield tip, and the direction of the magnetic field is also emitted from the electron shield folding screen or welding screen. It blows out in the direction to cancel the force received from the geomagnetism of the beam. As a result, the amount of magnetic field blown out from the tip of the electron shield is reduced compared to the conventional case, so that a cathode ray tube that reduces electron beam distortion due to the magnetic field blown out, reduces mislanding, and prevents color misregistration and color unevenness is provided. can do.
[0022]
Further, according to the second aspect of the present invention, by providing a welding screen part in which a magnetic metal material is welded to the mask frame, the location where the magnetic field flowing from the internal magnetic shield or the mask frame blows out is welded to the mask frame. The magnetic field is blown out in the direction in which the force received from the geomagnetism of the electron beam is canceled out from the welding screen of the mask frame. As a result, the amount of magnetic field blown out from the tip of the mask frame is reduced compared to the conventional case, so that a cathode ray tube that reduces electron beam distortion due to the blown-out magnetic field, reduces mislanding, and prevents color misregistration and color unevenness is provided. can do.
[Brief description of the drawings]
FIG. 1 is a schematic view of a cathode ray tube according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the vicinity of a shadow mask of the cathode ray tube according to Embodiment 1 of the present invention. FIG. 4 is a cross-sectional perspective view of the vicinity of the shadow mask of the cathode ray tube according to the first embodiment of the present invention. FIG. 5 is an electron shield shape and mislanding amount according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view of the vicinity of the shadow mask of the cathode ray tube in the second embodiment of the present invention. FIG. 7 shows the relationship between the mask frame shape and the mislanding amount in the second embodiment of the present invention. FIG. 8 is a schematic view of a cathode ray tube of a conventional television or personal computer monitor. FIG. 9 is a cross-sectional view of the vicinity of a shadow mask in a conventional cathode ray tube. Sectional view of the vicinity shadow mask in the line pipe [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Panel part 2 Funnel part 3 Phosphor screen 4 Shadow mask 5, 12 Mask frame 6 Internal magnetic shield 7 Electron beam 8 Electron shield 9 Bending screen part 10, 13 Welding screen part 11 Electron shield tip part 14 Mask frame tip part

Claims (4)

An envelope composed of at least a panel portion and a funnel portion, a shadow mask disposed opposite to a phosphor screen formed on the inner surface of the panel portion, a mask frame supporting the shadow mask, and a tube axis are attached coaxially. In the cathode ray tube comprising an inner magnetic shield disposed in the funnel portion, the inner magnetic shield includes an electron shield that projects inside the mask frame and shields the electron beam, and a magnetic metal is disposed in the longitudinal direction of the electron shield. A cathode ray tube comprising a screen part for welding and arranging a material . Cathode ray tube according to claim 1, characterized in that said partition portion is oriented tube axis and flat row direction. An envelope composed of at least a panel portion and a funnel portion, a shadow mask disposed opposite to a phosphor screen formed on the inner surface of the panel portion, a mask frame supporting the shadow mask, and a tube axis are attached coaxially. A cathode ray tube comprising an internal magnetic shield disposed in the funnel portion, wherein the cathode frame has a screen portion for welding a magnetic metal material to the mask frame. Cathode ray tube according to claim 3, characterized in that said partition portion is oriented tube axis and flat row direction.

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