JP2004029266A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display device wherein noise sounds in an audible area are not emitted in a cover consisting essentially of an inexpensive iron material. <P>SOLUTION: A noise filter circuit which is connected to an AC power source and has a noise filter 253 is arranged at the rear side of a plasma display panel, and a cover 28 made of a metallic material having magnetism is arranged at the rear side of the plasma display panel so as to cover the noise filter, and the noise filter 253 is covered with a magnetic shield member 29 to reduce the quantity of magnetic flux leakage to the cover 28, and as a result, noise sounds in the audible area are not emitted in the cover 28. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma display device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a plasma display device has been attracting attention as a display panel (thin display device) having excellent visibility, and higher definition and a larger screen are being promoted.
[0003]
This plasma display device is roughly classified into an AC type and a DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type. However, high definition, large screen, power consumption and At present, an AC type surface discharge type plasma display device has become the mainstream due to the simplicity of manufacturing.
[0004]
First, the structure of the plasma display panel in the plasma display device will be described with reference to FIG. As shown in FIG. 5, on a transparent front substrate 1 such as a glass substrate, a plurality of rows of stripe-shaped display electrodes 2 forming pairs of scan electrodes and sustain electrodes are formed, and cover the electrode group. A dielectric layer 3 is formed as described above, and a protective film 4 is formed on the dielectric layer 3.
[0005]
A plurality of rows of stripes covered with an overcoat layer 6 are provided on a rear substrate 5 opposed to the front substrate 1 so as to intersect with the display electrodes 2 of scan electrodes and sustain electrodes. Address electrodes 7 are formed. A plurality of partitions 8 are arranged on the overcoat layer 6 between the address electrodes 7 in parallel with the address electrodes 7, and the phosphor layers 9 are provided on the side surfaces between the partitions 8 and on the surface of the overcoat layer 6. I have.
[0006]
The substrate 1 and the substrate 5 are opposed to each other with a minute discharge space therebetween so that the display electrode 2 of the scan electrode and the sustain electrode and the address electrode 7 are substantially orthogonal to each other, and the periphery thereof is sealed. In the discharge space, one or a mixed gas of helium, neon, argon, and xenon is sealed as a discharge gas. The discharge space is partitioned into a plurality of partitions by partition walls 8, so that a plurality of discharge cells are provided at intersections between the display electrodes 2 and the address electrodes 7, and each of the discharge cells has a red, green, and blue color. The phosphor layers 9 are sequentially arranged for each color such that
[0007]
FIG. 6 shows an electrode arrangement of this plasma display panel. As shown in FIG. 6, the scan electrodes, the sustain electrodes, and the address electrodes have a matrix structure of M rows × N columns, and have M rows in the row direction. Scan electrodes SCN1 to SCNM and sustain electrodes SUS1 to SUSM are arranged, and N columns of address electrodes D1 to DN are arranged in the column direction.
[0008]
In the plasma display panel having such an electrode configuration, an address discharge is performed between the address electrode and the scan electrode by applying a write pulse between the address electrode and the scan electrode, and after selecting a discharge cell, the scan electrode A sustain discharge is performed between the scan electrode and the sustain electrode by applying a periodic sustain pulse that is alternately inverted between the scan electrode and the sustain electrode, thereby performing a predetermined display.
[0009]
FIG. 7 shows an example of the overall configuration of a plasma display device incorporating the panel having the structure described above. In the figure, a housing for accommodating a panel 10 is composed of a front frame 11 and a metal cover 12, and an opening of the front frame 11 is made of a front cover made of glass or the like which also protects the optical filter and the panel 10. 13 are arranged. The front cover 13 is coated with, for example, silver to suppress unnecessary radiation of electromagnetic waves. Further, the cover 12 is provided with a plurality of ventilation holes 12a for releasing heat generated in the panel 10 and the like to the outside.
[0010]
The panel 10 is held by bonding a front surface of a chassis member 14 made of aluminum or the like through a heat conductive sheet 15, and a plurality of circuits for driving the display of the panel 10 are provided on the rear side of the chassis member 14. A block 16 is attached. The heat conductive sheet 15 is for efficiently transmitting the heat generated in the panel 10 to the chassis member 14 and radiating the heat. Further, the circuit block 16 includes an electric circuit for performing display driving of the panel 10 and controlling the same, and the electrode drawing portion drawn to the edge portion of the panel 10 extends beyond the four edge portions of the chassis member 14. It is electrically connected by a plurality of extending flexible wiring boards (not shown).
[0011]
A boss 14a for attaching the circuit block 16 and fixing the cover 12 is provided on the rear surface of the chassis member 14 by integral molding using die casting or the like. The chassis member 14 may be configured by fixing a fixing pin to an aluminum flat plate.
[0012]
[Problems to be solved by the invention]
However, in such a plasma display device, when the material of the cover is changed from aluminum to an inexpensive iron material, noise in the audible range is generated in AC100V and AC120V which are AC power supply ranges in Japan and the United States where the power supply voltage is low. There was a problem that it would occur. In particular, in a plasma display device using an AC-DC rectifier circuit of a capacitor input type as a power supply circuit, there is a problem that an audible noise is generated.
[0013]
The present invention solves such a problem and provides a plasma display device free of noise sound in an audible range.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a plasma display device according to the present invention has a noise filter circuit, which is connected to an AC power supply and has a noise filter, disposed on a chassis member provided on the rear side of the plasma display panel. The plasma display panel is constituted by disposing a cover made of a magnetic metal material on the back side of the plasma display panel so as to cover the circuit, and the noise filter is covered with a magnetic shield member.
[0015]
According to the present invention, since the magnetic field lines in the core of the magnetic material constituting the noise filter are cut off by the magnetic shield member, the amount of leakage magnetic flux generated between the different windings of the AC line to the cover can be reduced. Since it is possible to reduce the noise, it is possible to provide a plasma display device in which noise noise in the audible range is less generated.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
That is, according to the invention of claim 1 of the present invention, a noise filter circuit connected to an AC power supply and having a noise filter is disposed on a chassis member disposed on the back side of the plasma display panel, and the noise filter circuit is provided. A cover made of a metal material having magnetism is disposed on the back side of the plasma display panel so as to cover the noise filter, and the noise filter is covered with a magnetic shield member, and the amount of magnetic flux leakage to the cover is reduced. As a result, an audible noise sound is not generated on the cover.
[0017]
According to a second aspect of the present invention, a driving circuit for driving a plasma display panel, a power supply circuit for supplying power to the driving circuit, and an AC power supply are provided on a chassis member disposed on the back side of the plasma display panel. A noise filter circuit having a noise filter connected thereto is disposed, and a cover made of a magnetic metal material is disposed on the back side of the plasma display panel so as to cover the drive circuit, the power supply circuit, and the noise filter circuit. The noise filter is covered with a magnetic shield member, and a flame-retardant insulating resin is filled between the noise filter and the magnetic shield member. Filled with insulating resin to create magnetic shield parts with both insulating and flame retardant properties It is possible to reduce the magnetic flux leakage amount to cover, and has an effect of noise sound is not generated in the audible range in a result cover.
[0018]
Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to FIGS.
[0019]
1 and 2 show a main configuration of a plasma display device according to an embodiment of the present invention.
[0020]
As shown in the drawing, the plasma display device has a plasma display panel 21 in which a heat dissipating aluminum base 212 as a chassis member is disposed on the back side of a panel main body 211 having the configuration shown in FIG. A driving circuit 22 including a data driving circuit 221 for supplying data for discharging predetermined discharge cells and a discharge driving circuit 222 for discharging and emitting light from the discharge cells, and a driving signal for supplying a signal for driving the plasma display panel 21 to the driving circuit 22 It comprises a processing circuit 23, a power supply circuit 24 for supplying power to the drive circuit 22 and the drive signal processing circuit 23, and a noise filter circuit 25 connected to an AC power supply. The flat display cable 26 is connected between the plasma display panel 21 and the driving circuit 22, the data driving circuit 221 and the driving signal processing circuit 23. Although not shown, a signal and a power supply line are connected between each circuit by a conductor. Further, in order to protect the plasma display panel 21, the plasma display device includes a front cover 27 made up of a front glass 271, a holding plate 272, and an escutcheon 273, and a back side made of a magnetic metal material mainly composed of iron or the like. Cover 28 is provided.
[0021]
As shown in FIG. 3, a noise filter circuit 25 connected to an AC power supply is a printed circuit board that constitutes the noise filter circuit 25 on a metal fitting 251 attached to an aluminum base 212 disposed on the back side of the plasma display panel 21. 252 is fixed, and a common mode noise filter 253, a film capacitor for removing noise (not shown), a surge absorbing element, a fuse and the like are mounted on the printed board 252. In FIG. 3, A indicates the direction of the leakage magnetic flux.
[0022]
A cover 28 made of a magnetic metal material is disposed on the back side of the plasma display panel 21 so as to cover the noise filter circuit 25. The noise filter 253 of the noise filter circuit 25 is made of aluminum. It is configured to be covered with a magnetic shield member 29 made of a plate and filled with a flame-retardant insulating resin 30 between the noise filter 253 and the magnetic shield member 29. The magnetic shield member 29 is fixed to the printed board 252.
[0023]
FIG. 4 shows a state where a noise filter 253 is mounted in a conventional plasma display device. That is, in the related art, the noise filter 253 is mounted in a direction in which the direction of the magnetic force line of the noise filter 253 is orthogonal to the in-plane direction of the surface close to the cover 28. The cover 28 was affected by the influence, and vibration was generated in the cover 28 by the strength of the leakage magnetic flux, thereby generating noise.
[0024]
On the other hand, according to the configuration of the present invention, the leakage magnetic flux generated in the noise filter 253 is blocked by the magnetic shield member 29, and the amount of the leakage magnetic flux passing through the cover 28 can be reduced. As a result, it is possible to reduce the noise sound generated by the repetition of the attraction between the noise filter 253 and the cover 28 due to the strength of the leakage magnetic flux due to the AC current linked to the AC power supply frequency.
[0025]
In the above description, an example in which the cover 28 also serves as an exterior housing has been described. However, separately from the cover 28 made of a metal material, a case made of an exterior synthetic resin may be placed over the cover 28. The same operation and effect can be obtained in the case of providing the same.
[0026]
【The invention's effect】
As is clear from the above description, according to the plasma display device of the present invention, the noise filter circuit connected to the AC power supply and having the noise filter is disposed on the chassis member disposed on the back side of the plasma display panel. And a cover made of a magnetic metal material is disposed on the back side of the plasma display panel so as to cover the noise filter circuit, and the noise filter is covered with a magnetic shield member, and the magnetic flux to the cover is Since the amount of leakage can be reduced, the effect of reducing noise in the audible range in the cover is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an internal configuration of a plasma display device according to an embodiment of the present invention; FIG. 2 is a schematic plan view of the plasma display device with a cover removed; FIG. FIG. 4 is a front view showing a main part configuration of a conventional plasma display device. FIG. 5 is a perspective view showing a schematic configuration of a panel of the plasma display device. FIG. FIG. 7 is an exploded perspective view showing an internal arrangement structure of the plasma display device.
Reference Signs List 21 Plasma display panel 22 Drive circuit 23 Drive signal processing circuit 24 Power supply circuit 25 Noise filter circuit 28 Cover 29 Magnetic shield member 30 Flame retardant insulating resin 253 Noise filter

Claims (2)

A noise filter circuit connected to an AC power supply and having a noise filter is disposed on a chassis member disposed on the rear side of the plasma display panel, and has a magnetism on the rear side of the plasma display panel so as to cover the noise filter circuit. A plasma display device comprising a cover made of a metal material, wherein the noise filter is covered with a magnetic shield member. A driving circuit for driving the plasma display panel, a power supply circuit for supplying power to the driving circuit, a noise filter circuit connected to an AC power supply and having a noise filter, on a chassis member disposed on the back side of the plasma display panel; And a cover made of a magnetic metal material is arranged on the back side of the plasma display panel so as to cover the drive circuit, the power supply circuit and the noise filter circuit, and the noise filter is made of a magnetic material. A plasma display device comprising a shield member and a flame-retardant insulating resin filled between a noise filter and a magnetic shield member.

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