JP2006338931A - Color cathode-ray tube device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an electric discharge from a fixing band for fixing a deflection yoke to a vacuum container without having increase of cost. <P>SOLUTION: A conductive film 26 is applied on a part of inner face of the vacuum container 20. The deflection yoke 60 mounted on the outer peripheral face of the vacuum container 20 is fixed to the vacuum container 20 by using a fixing band 67 composed of a conductive material in the vicinity of the neck part 23 side edge of the deflection yoke 60. In the tube axial direction, the neck part 23 side edge 26r of the conductive film 26 is positioned on the panel part 21 side against the panel part 21 side edge 67f of the fixing band 67. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a color cathode ray tube apparatus.

  FIG. 4 is a diagram showing a schematic configuration of an example of a general color cathode ray tube apparatus 1. In FIG. 4, a sectional view is shown above the tube axis (hereinafter referred to as “Z-axis”), and an external view is shown below. The color cathode ray tube apparatus 1 shown in FIG. 4 includes a color cathode ray tube 2, a deflection yoke 60, a magnet unit 70, a scanning speed modulation coil 80, and the like.

  FIG. 5 is a cross-sectional view showing a configuration around the deflection yoke 60 and the electron gun 30 as an example of a conventional color cathode ray tube apparatus.

  A conventional color cathode ray tube apparatus will be described with reference to FIGS.

  The color cathode ray tube 2 includes a panel portion 21, a neck portion 23, and a funnel portion 22 having a substantially funnel shape disposed between the panel portion 21 and the neck portion 23. The funnel portion 22 has a large diameter side on the panel portion 21 side and a small diameter side on the neck portion 23 side. The vacuum vessel 20 is provided. On the inner surface of the panel portion 21, a screen 24 is formed by regularly applying red, green, and blue phosphors in a dot or stripe form. The shadow mask 25 is fixed to the inner wall surface of the panel portion 21 with a substantially constant interval from the screen 24. The shadow mask 25 is provided with a number of electron beam passage holes.

  An electron gun 30 that emits three electron beams 38 corresponding to three colors of red, green, and blue is built in the neck portion 23. The electron gun 30 includes three cathodes, a plurality of electrodes arranged in the Z-axis direction, and a shield cup 31 arranged at a position closest to the panel unit 21. A plurality of centering springs 32 are cantilevered on the shield cup 31.

  A conductive film 26 is formed on a part of the inner surface of the neck portion 23 and the funnel portion 22 by coating. The conductive film 26 electrically connects the anode button 28 provided in the funnel portion 22 and the centering spring 32 held by the shield cup 31 of the electron gun 30. Thereby, a high voltage (referred to as an anode voltage) is supplied to the electron gun 30 from outside the tube through the anode button 28, the conductive film 26, and the centering spring 32 in this order.

  A deflection yoke 60 is mounted on the outer peripheral surface of the vacuum vessel 20 in the vicinity of the joint portion 27 between the funnel portion 22 and the neck portion 23 in the Z-axis direction. The deflection yoke 60 includes a saddle type horizontal deflection coil 62 and a toroidal type vertical deflection coil 64 wound around a ferrite core 63. The three electron beams 38 emitted from the electron gun 30 are deflected in the horizontal direction and the vertical direction by the horizontal deflection magnetic field generated by the horizontal deflection coil 62 and the vertical deflection magnetic field generated by the vertical deflection coil 64, and are raster scanned on the screen 24. Scan by method. An insulating frame 65 made of a resin material is provided between the horizontal deflection coil 62 and the vertical deflection coil 64. The insulating frame 65 maintains the electrical insulation state between the horizontal deflection coil 62 and the vertical deflection coil 64 and plays a role of supporting both the deflection coils 62 and 64. The deflection yoke 60 is fixed to the vacuum vessel 20 by a fixing band 67 made of a conductive material (for example, a metal material) attached to the outer peripheral surface of the insulating frame 65 in the vicinity of the end of the insulating frame 65 on the neck portion 23 side. . The fixed band 67 is composed of, for example, a member in which a strip-shaped metal plate is formed in a substantially Ω shape, and bolts for fastening both ends thereof. An auxiliary coil 66 for assisting a vertical deflection magnetic field is attached to the insulating frame 65 at a position closer to the neck portion 23 than the horizontal deflection coil 62 in the Z-axis direction.

  The magnet unit 70 is provided on the outer peripheral surface of the neck portion 23 at a position overlapping with the electron gun 30 in the Z-axis direction, and performs static convergence adjustment of the electron beam 38. The magnet unit 70 includes at least a quadrupole magnet 71 composed of a pair of annular magnets that generate a quadrupole magnetic field, and a hexapole magnet 72 composed of a pair of annular magnets that generate a hexapole magnetic field. The 4-pole magnet 71 and the 6-pole magnet 72 are mounted on the outer peripheral surface of a cylindrical resin frame 75. The resin frame 75 is extrapolated on the neck portion 23 and is fixed to the neck portion 23 by a fixing band 77.

  The scanning speed modulation coil 80 is composed of a pair of loop coils wound around the outer peripheral surface of the resin frame 75 with a horizontal plane including the Z-axis interposed therebetween. The scanning speed modulation coil 80 enhances the contour of an image by generating a magnetic field in the vertical direction and modulating the horizontal scanning speed of the electron beam.

  In the above-described color cathode ray tube apparatus, the relative positional relationship in the Z-axis direction between the fixed band 67 of the deflection yoke 60 and the conductive film 26 in the vacuum vessel 20 will be described below. For convenience of explanation, in the Z-axis direction, the panel portion 21 side is referred to as “front side”, and the neck portion 23 side is referred to as “rear side”.

  Conventionally, the neck portion 23 side end (ie, the rear end) 26r of the conductive film 26 is closer to the neck portion 23 side (ie, the Z band direction than the panel portion 21 side end (ie, front end) 67f of the fixing band 67). , Rear side). That is, in the Z-axis direction, the conductive film 26 extends from the funnel portion 22 side to the rear side of the fixed band 67. This is due to the following reason. When the electron gun 30 and the deflection magnetic field generated by the deflection yoke 60 are close to each other in the Z-axis direction, the focus characteristic of the spot formed on the screen 24 by the electron beam 38 deteriorates. Therefore, the electron gun 30 needs to be arranged away from the deflection yoke 60. Therefore, the conductive film 26 that supplies the anode voltage to the electron gun 30 needs to be extended to the rear side of the fixed band 67.

  However, when an anode voltage, which is a high voltage, is applied to the conductive film 26, an electric charge is instantaneously induced in the fixed band 67 made of a conductive material surrounding the conductive film 26 when the anode voltage is applied. When the induced voltage generated in the fixed band 67 is high, a discharge is generated between the auxiliary coil 66 disposed in the vicinity thereof, and the deflection circuit connected thereto may be destroyed. Alternatively, discharge may occur between the scanning speed modulation coil 80 and the scanning speed modulation circuit connected thereto may be destroyed.

In order to prevent this discharge, conventionally, a lead wire is attached to the fixed band 67 and connected to the ground, or an induced voltage is suppressed by using an insulating material such as a resin as the material of the fixed band 67. Measures have been taken to cover the scanning speed modulation coil 80 with an insulator (see, for example, Patent Document 1).
JP-A-6-103925

  However, any of the above measures increases the cost, and has been a problem in dealing with the recent low price competition.

  An object of the present invention is to provide a color cathode ray tube apparatus in which discharge from the fixed band 67 is unlikely to occur without causing a significant increase in cost.

The color cathode ray tube apparatus according to the present invention is
A panel portion having a screen coated with a phosphor on the inner surface, a neck portion, and disposed between the panel portion and the neck portion, the panel portion side being a large diameter side and the neck portion side being a small diameter side A vacuum vessel consisting of a substantially funnel-shaped funnel part,
A conductive film applied to a part of the inner surface of the neck part and the funnel part,
An electron gun that is built in the neck and emits a plurality of electron beams;
In the tube axis direction, the electron beam is disposed near the junction between the funnel portion and the neck portion, mounted on the outer peripheral surface of the vacuum vessel, and the plurality of electron beams emitted from the electron gun are horizontally and vertically oriented. Deflection yoke,
A fixing band made of a conductive material for fixing the deflection yoke to the vacuum vessel in the vicinity of the neck side end of the deflection yoke; and
In the tube axis direction, at least a quadrupole magnetic field and a hexapole magnetic field are disposed on the neck portion side with respect to the deflection yoke, and are fixed on the outer peripheral surface of the neck portion by fixing means separate from the deflection yoke. A plurality of generated magnets are provided.

  In the tube axis direction, the neck portion side end of the conductive film is located on the panel portion side with respect to the panel portion side end of the fixed band.

  According to the present invention, since the voltage induced in the fixed band of the deflection yoke is reduced, the discharge from the fixed band can be suppressed at a low cost. Therefore, a safe and inexpensive color cathode ray tube apparatus can be provided.

  The configuration of the color cathode ray tube device of the present invention is such that a rear end (neck portion side end) 26r of the conductive film 26 formed on the inner surface of the vacuum vessel 20 and a fixing band 37 for fixing the deflection yoke 60 to the vacuum vessel 20 are used. There is no particular limitation except for the relative positional relationship in the tube axis direction with respect to the front end (panel portion side end) 67f, and for example, it may have the same configuration as in FIG. Therefore, the overlapping description is omitted and the characteristic configuration of the present invention will be described below.

  FIG. 1 is a cross-sectional view showing a configuration around a deflection yoke 60 and an electron gun 30 in a color cathode ray tube apparatus according to an embodiment of the present invention. The same components as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted.

  In the embodiment shown in FIG. 1, the neck portion 23 side end (that is, the rear end) 26r of the conductive film 26 is more in the Z-axis direction than the panel portion 21 side end (that is, the front end) 67f of the fixing band 67. It is different from FIG. 5 in that it is located on the panel unit 21 side (that is, the front side). As a result, in FIG. 1, compared with FIG. 5, the distance from the deflection yoke 60 to the electron gun 30 is reduced, and the electron gun 30 is moved substantially to the front side.

  The relationship between the relative positional relationship between the rear end 26r of the conductive film 26 and the front end 67f of the fixed band 67 in the Z-axis direction and the voltage induced in the fixed band 67 when the anode voltage is applied was obtained by experiments. The results are shown in FIG. In this experiment, the dimension of the fixed band 67 in the Z-axis direction was 8 mm. In FIG. 2, the horizontal axis indicates the position of the front end 67f of the fixed band 67 in the Z-axis direction, and the position of the rear end 26r of the conductive film 26 is the origin (Z = 0 mm). The rear side (neck portion 23 side) is the positive side of the Z axis.

  From FIG. 2, the voltage induced in the fixed band 67 is about 10 kV in the case of “fixed band position (b)” where the Z-axis direction positions of the fixed band 67 and the conductive film 26 overlap each other as in the prior art. On the other hand, in the case of the “fixed band position (a)” in which the Z-axis direction positions of the fixed band 67 and the conductive film 26 do not overlap each other as in the present invention, it is about 6 kV, which is reduced to about half. I understand that. In general, since the distance between the fixed band 67 and the auxiliary coil 66 or the scanning speed modulation coil 80 can be ensured to be about 7 mm or more, the occurrence of discharge can be avoided even if a voltage of about 6 kV or less is induced in the fixed band 67.

  Next, the relative positional relationship in the Z-axis direction between the rear end 26r of the conductive film 26 and the front end 67f of the fixed band 67, and the probability of occurrence of discharge between the fixed band 67 and the auxiliary coil 66 when the anode voltage is applied. The relationship was obtained through experiments. The results are shown in FIG. Similar to the case of FIG. 2, the dimension of the fixed band 67 in the Z-axis direction was 8 mm. 3, the horizontal axis indicates the position of the front end 67f of the fixed band 67 in the Z-axis direction and the position of the rear end 26r of the conductive film 26 as the origin (Z = 0 mm), as in FIG. The rear side (neck portion 23 side) is the positive side of the Z axis. The vertical axis indicates the ratio of the number of discharge occurrences between the fixed band 67 and the auxiliary coil 66 with respect to the number of times of anode voltage application ON by repeatedly performing the ON / OFF operation of the anode voltage application of 30 kV. The shortest distance between the fixed band 67 and the auxiliary coil 66 was 7.0 mm.

  From FIG. 3, the discharge probability between the fixed band 67 and the auxiliary coil 66 is the case of “fixed band position (b)” where the Z-axis direction positions of the fixed band 67 and the conductive film 26 overlap each other as in the prior art. However, in the case of the “fixed band position (a)” in which the Z-axis direction positions of the fixed band 67 and the conductive film 26 do not overlap each other as in the present invention, it is about 0%. It turns out that it falls. Therefore, according to the present invention, the occurrence of discharge from the fixed band 67 can be suppressed.

  In the present invention, since the electron gun 30 is closer to the deflection yoke 60 than in the prior art (see FIG. 5), there is a concern about deterioration of the focus characteristics. However, this problem can be solved by measures such as changing the dimension of the shield cup 31 in the Z-axis direction or adopting a magnetic material as an electrode constituting the electron gun 30. In addition, the cost required for this measure is small compared to the cost required for the conventional discharge prevention measure.

  The above embodiments and experimental results are examples, and the present invention is not limited to these. For example, the value of the induced voltage shown in FIG. 2 and the value of the discharge probability shown in FIG. 3 vary depending on the size of the cathode ray tube device, various specifications, experimental conditions, and the like. Moreover, although the Z-axis direction dimension of the fixed band 67 is 8 mm in the above experiment, it is not limited to this. Generally, it is 7-8 mm.

  The field of use of the present invention is not particularly limited, and can be widely used for television receivers, computer displays, and the like.

It is sectional drawing which showed the structure of the periphery of a deflection | deviation yoke and an electron gun of the color cathode ray tube apparatus which concerns on one Embodiment of this invention. The relationship between the relative position in the tube axis direction between the neck side end (rear end) of the conductive film and the panel side end (front end) of the fixed band for fixing the deflection yoke, and the induced voltage of the fixed band. It is the figure which showed the experimental result investigated. The relationship between the relative position in the tube axis direction between the neck side end (rear end) of the conductive film and the panel side end (front end) of the fixed band for fixing the deflection yoke, and the discharge probability from the fixed band It is the figure which showed the experimental result which investigated this. It is the half section side view showing the schematic structure of an example of a general color cathode ray tube device. It is sectional drawing which showed the structure of the periphery of a deflection | deviation yoke and an electron gun of an example of the conventional color cathode ray tube apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color cathode ray tube apparatus 2 Color cathode ray tube 20 Vacuum vessel 21 Panel part 22 Funnel part 23 Neck part 24 Screen 25 Shadow mask 26 Conductive film 27 Junction part 28 of a funnel part and a neck part Anode button 30 Electron gun 31 Shield cup 32 Centering Spring 38 Electron beam 60 Deflection yoke 62 Horizontal deflection coil 64 Vertical deflection coil 63 Ferrite core 65 Insulating frame 66 Auxiliary coil 67 Fixed band 70 Magnet unit 71 4-pole magnet 72 6-pole magnet 75 Resin frame 77 Fixed band 80 Scanning speed modulation coil

Claims (1)

A panel portion having a screen coated with a phosphor on the inner surface, a neck portion, and disposed between the panel portion and the neck portion, the panel portion side being a large diameter side and the neck portion side being a small diameter side A vacuum vessel consisting of a substantially funnel-shaped funnel part,
A conductive film applied to a part of the inner surface of the neck part and the funnel part,
An electron gun that is built in the neck and emits a plurality of electron beams;
In the tube axis direction, the electron beam is disposed near the junction between the funnel portion and the neck portion, mounted on the outer peripheral surface of the vacuum vessel, and the plurality of electron beams emitted from the electron gun are horizontally and vertically oriented. Deflection yoke,
A fixing band made of a conductive material for fixing the deflection yoke to the vacuum vessel in the vicinity of the neck side end of the deflection yoke; and
In the tube axis direction, at least a quadrupole magnetic field and a hexapole magnetic field are disposed on the neck portion side with respect to the deflection yoke, and are fixed on the outer peripheral surface of the neck portion by fixing means separate from the deflection yoke. A color cathode ray tube apparatus having a plurality of magnets each generated,
The color cathode ray tube apparatus according to claim 1, wherein the neck portion side end of the conductive film is located on the panel portion side with respect to the panel portion side end of the fixed band in the tube axis direction.

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