KR20040085766A - Electromagnetic wave shielding film of plasma display panel - Google Patents

Abstract

PURPOSE: An electromagnetic interference shielding film is provided to achieve improved transmissivitty and minimize moire phenomenon by arranging a conductive mesh having polygonal holes having internal angles larger than a square. CONSTITUTION: An electromagnetic interference shielding film(84) comprises a mesh pattern(82) having a conductivity; polygonal holes formed by the mesh pattern, and which have internal angles larger than a square; a frame(80) formed along the periphery of the mesh pattern so as to support the mesh pattern; a transparent substrate for supporting the mesh pattern; and a transparent conductive film for supporting the mesh pattern, and which has a conductivity.

Description

Electromagnetic shielding film of plasma display panel {ELECTROMAGNETIC WAVE SHIELDING FILM OF PLASMA DISPLAY PANEL}

The present invention relates to an electromagnetic wave shielding film, and more particularly, to an electromagnetic wave shielding film of a plasma display panel having a structure capable of minimizing a moiré phenomenon while securing transmittance.

In general, an electromagnetic shielding film for shielding electromagnetic radiation emitted to the outside is provided on the front surface of the display device for displaying an image. The electromagnetic shielding film has a conductive pattern in the form of a mesh in order to shield electromagnetic waves and to secure visible light transmittance required by a display device. However, the conventional conductive pattern in the form of a mesh has a problem of lowering the visible light transmittance and causing a moare phenomenon to deteriorate the image quality. Hereinafter, a plasma display panel (hereinafter referred to as PDP) for displaying an image using gas discharge will be described in detail with respect to the problem of the conventional electromagnetic shielding film.

The PDP displays an image by adjusting the gas discharge period of each of the pixels according to the digital video data. As such a PDP, an AC type PDP having three electrodes and driven by an AC voltage is typical.

1 is a perspective view of a structure of an AC (AC) type PDP, in particular, showing a structure of a discharge cell corresponding to one sub-pixel.

The discharge cell shown in FIG. 1 includes an upper plate 15 having sustain electrode pairs 12A and 12B, an upper dielectric layer 14, and a protective layer 16 sequentially formed on the upper substrate 10, and the lower substrate 18. A lower plate 25 having a data electrode 20, a lower dielectric layer 22, a partition wall 24, and a phosphor layer 26 sequentially formed thereon is provided.

The upper substrate 10 and the lower substrate 18 are spaced apart in parallel by the partition wall 24. Each of the sustain electrode pairs 12A and 12B has a relatively wide width and is composed of a transparent electrode for transmitting visible light, and a relatively narrow width and metal electrode for compensating for the resistance component of the transparent electrode. The sustain electrode pairs 12A and 12B are constituted by the scan electrode 12A and the sustain electrode 12B. The scan electrode 12A mainly supplies a scan signal for determining the data supply time and a sustain signal for sustaining discharge, and the sustain electrode 12B mainly supplies a sustain signal for sustaining the discharge. Charges generated during gas discharge are accumulated in the upper dielectric layer 14 and the lower dielectric layer 22. The protective layer 16 prevents damage to the upper dielectric layer 14 due to the sputtering of the plasma, thereby increasing the lifetime of the PDP and increasing the emission efficiency of the secondary electrons. As the protective film 16, magnesium oxide (MgO) is usually used. The dielectric layers 14 and 22 and the protective layer 16 may lower the discharge voltage applied from the outside. The data electrode 20 is formed to cross the storage electrode pairs 12A and 12B. This data electrode 20 supplies a data signal for selecting the cells to be displayed. The partition wall 24 forms a discharge space together with the upper and lower substrates 10 and 18, and is formed in parallel with the data electrode 20 to prevent the ultraviolet rays generated by the gas discharge from leaking into adjacent cells. The phosphor layer 26 is applied to the surfaces of the lower dielectric layer 22 and the partition wall 24 to generate visible light of any one of red, green, and blue. The discharge space is filled with an inert gas such as He, Ne, Ar, Xe, Kr for gas discharge, a discharge gas having a combination thereof, or an excimer gas capable of generating ultraviolet rays by discharge.

The discharge cell of this structure is selected by the counter discharge between the data electrode 20 and the scan electrode 12A, and then holds the discharge by the surface discharge between the sustain electrode pairs 12A and 12B. As a result, in the discharge cell, the fluorescent material 26 emits light by ultraviolet rays generated during sustain discharge, so that visible light is emitted outside the cell. In this case, the discharge cell implements a gray scale by adjusting the discharge sustain period of the cell, that is, the number of sustain discharges, according to the video data.

FIG. 2 is an exploded perspective view schematically showing a PDP set including the PDP 30 shown in FIG. 1.

The PDP set illustrated in FIG. 2 includes a case 60, a printed circuit board (hereinafter referred to as a PCB) 50, a PDP 30, and a glass type front filter 40 housed in the case 60. And a cover 70 which is fastened to the case 60 while surrounding the front outer portion of the glass type front filter 40.

The PDP 30 is formed by joining the upper plate 15 and the lower plate 25 as shown in FIG. 1.

The PCB 50 located on the rear side of the PDP 30 includes a plurality of driving and control circuits for driving the sustain electrode pairs 12A and 12B and the address electrode 20 formed in the PDP 30. A heat sink (not shown) for dissipating heat emitted from the PDP 30 and the PCB 50 is installed between the PCB 50 and the PDP 30.

The glass type front filter 40 has functions such as electromagnetic shielding, external light reflection prevention, near infrared shielding, and color correction generated from the PDP 30 to the front side. To this end, the glass type front filter 40 has a first anti-reflection film 44 attached to the front surface of the glass substrate 42 and electromagnetic waves sequentially attached to the rear surface of the glass substrate 42 as shown in FIG. 3. A shielding film 46, a near infrared shielding film 48, a color correction film 52, and a second antireflection film 54 are provided.

The glass substrate 42 supports the glass type front filter 40 by using tempered glass, and protects the front filter 40 and the PDP 30 from being damaged by an external impact. The first and second antireflection films 44 and 54 improve contrast by preventing light incident from the outside from being reflected back to the outside. The electromagnetic shielding film 46 absorbs electromagnetic waves generated from the PDP 30 to shield the electromagnetic waves from being emitted to the outside. The near-infrared shielding film 48 absorbs near-infrared rays of about 800-1000 nm wavelength band generated by the PDP 30 to shield them from being radiated to the outside. Allows normal input to the infrared receiver provided in the PDP set without interference. The color correction layer 52 includes a color control dye (Color Dye) to increase the color purity by adjusting the color tone. These multiple films 44, 46, 48, 52, 54 are attached to the glass substrate 42 via adhesive or adhesive.

The case 60 protects the PDP 30 accommodated together with the PCB 50 and the glass-type front filter 40 from external shocks and shields electromagnetic waves emitted to the side and the back of the PDP 30. In addition, the case 60 includes an electromagnetic shielding film 46 of the glass front filter 40 through a support member (not shown) that supports the glass front filter 40 on the rear side thereof to be spaced apart from the PDP 30. Electrically connected. Accordingly, the case 60 is grounded together with the electromagnetic shielding film 46 of the glass-type front filter 40 to absorb and discharge electromagnetic waves emitted from the PDP 30 to shield the electromagnetic waves from being emitted to the outside. do.

The cover 70 is fastened to the case 60 while surrounding the front outer portion of the glass type front filter 40.

As such, the conventional PDP set uses a glass type front filter 40 for shielding electromagnetic waves and correcting optical characteristics. However, the glass type front filter 40 includes a relatively thick glass substrate, i.e., tempered glass 42, which is not only a major cause of increasing the thickness and weight of the PDP set, but also has a disadvantage of high manufacturing cost.

Accordingly, a film type front filter in which the glass substrate is removed as shown in FIG. 4 has been proposed. The film type front filter 60 illustrated in FIG. 4 includes a color correction film 68, a near infrared shielding film 66, an electromagnetic wave shielding film 64, and an antireflection film that are sequentially attached to the upper plate 15 of the PDP 30. 62).

The anti-reflection film 62 prevents light incident from the outside from being reflected back to the outside. The electromagnetic wave shielding film 64 absorbs and discharges electromagnetic waves generated from the PDP 30 to shield the electromagnetic waves from being emitted to the outside. The near-infrared shielding film 66 absorbs the near-infrared generated from the PDP 30 and shields it from being radiated to the outside. The color correction film 68 includes a color control dye to increase color purity by adjusting the color tone. Such a plurality of thin films 62, 64, 66, 68 are attached to the top plate 15 of the PDP 30 through an adhesive or an adhesive.

Thus, the glass type front filter 40 and the film type front filter 60 shown in FIG. 3 are equipped with the electromagnetic wave shielding film 46 and 64 for shielding the electromagnetic wave which generate | occur | produced from the PDP 30. As shown in FIG. The electromagnetic shielding films 46 and 64 include a conductive mesh 72 and a frame 70 supporting the conductive mesh 72 as shown in FIG. 5 to secure transmittance. The conductive mesh 72 is formed by patterning a metal layer using silver (Ag), copper (Cu), or the like by a photolithography process. In this case, the conductive mesh 72 having the cross structure is provided with holes having a rectangular shape inclined to transmit visible light. However, there is a problem in that the diffraction phenomenon of the visible light emitted from the PDP 30 is prominent at the corners of the conductive mesh 72 providing the rectangular holes, that is, the intersections of the conductive patterns. Accordingly, the conventional electromagnetic wave shielding films 46 and 64 inevitably cause a problem of deterioration in image quality such as moiré.

Accordingly, an object of the present invention is to provide an electromagnetic wave shielding film of a PDP having a structure capable of minimizing the moiré phenomenon while ensuring transmittance.

1 is a perspective view showing the structure of a conventional three-electrode AC surface discharge type plasma display panel.

FIG. 2 is an exploded perspective view of a plasma display panel set including the plasma display panel shown in FIG. 1.

3 is a cross-sectional view illustrating a vertical structure of the glass front filter and the plasma display panel shown in FIG.

4 is a cross-sectional view showing a vertical structure of a plasma display panel to which a conventional film type front filter is attached.

5 is a plan view illustrating a specific structure of the electromagnetic shielding film illustrated in FIGS. 3 and 4.

6 is a plan view showing the structure of the electromagnetic shielding film according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

10: upper substrate 12A: scanning electrode

12B: sustain electrode 14, upper dielectric layer

15: top plate 16: protective film

18: lower substrate 20: data electrode

22: lower dielectric layer 24: partition wall

26 phosphor 25: lower plate

30: PDP 40: glass type front filter

50: PCB 60: Case

70: cover 42: glass substrate

44, 48, 54: antireflection film 46, 64, 84: electromagnetic shielding film

48, 66: near-infrared shielding film 52: color correction film

60: film type front filter 70, 80: frame

72, 82: mesh pattern

In order to achieve the above object, the electromagnetic shielding film of the PDP according to the present invention is a mesh pattern having conductivity; It characterized in that it comprises a polygonal holes provided by the mesh pattern having a larger angle than the square.

The polygonal holes are characterized by having any one of a pentagonal shape, hexagonal shape, and octagonal shape.

And, the electromagnetic shielding film of the present invention is characterized in that it further comprises a frame formed along the outside of the mesh pattern to support the mesh pattern.

In addition, the electromagnetic shielding film of the present invention is characterized by further comprising a transparent substrate for supporting the mesh pattern.

Furthermore, the electromagnetic wave shielding film of the present invention is characterized by further comprising a transparent conductive film supporting the mesh pattern and having conductivity.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIG. 6.

6 shows an electromagnetic shielding film 84 according to an embodiment of the present invention.

The electromagnetic wave shielding film 84 shown in FIG. 6 includes a conductive mesh 82 and a frame 80 supporting the conductive mesh 82.

The conductive mesh 82 is formed in the effective screen area, and the frame 80 is formed in the outer portion of the effective screen area, that is, the invalid screen area.

The conductive mesh 82 is formed by patterning a metal layer using silver (Ag), copper (Cu), or the like by a photolithography process. In this case, in order to secure the visible light transmittance from the display device, for example, the PDP, located at the rear portion of the electromagnetic shielding film 84, the conductive mesh 82 is provided with holes having a polygonal structure.

In particular, the conductive mesh 82 allows polygonal holes having a larger internal angle than conventional rectangular holes in order to minimize visible light diffraction at the corners. For example, the conductive mesh 82 is formed in a honeycomb form as shown in FIG. 6 to form hexagonal holes. In addition, the conductive mesh 82 may be provided with polygonal holes such as pentagons, octagons, etc. having a larger angle than the rectangular holes.

Accordingly, the visible light diffraction phenomenon from the PDP at each corner of the conductive mesh 82 is minimized, thereby minimizing the moiré phenomenon that degrades the image quality.

In addition, the electromagnetic shielding film may further include a transparent substrate supporting the conductive mesh 82 for forming polygonal holes having a larger angle than a quadrangle, or may include indium tin oxide (ITO), indium tin oxide (IZO), or the like. The same transparent conductive film may be further provided.

As described above, the electromagnetic shielding film of the PDP according to the present invention includes a conductive mesh for forming a polygonal hole having an inner angle larger than a square, thereby ensuring a transmittance while minimizing visible light diffraction due to the conductive mesh, thereby minimizing the moiré phenomenon. To be able.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A mesh pattern having conductivity; And a plurality of polygonal holes provided by the mesh pattern and having an inner angle greater than a square. The method of claim 1, The polygonal hole has a form of any one of a pentagonal, hexagonal, octagonal electromagnetic shielding film of the plasma display panel. The method of claim 1, And a frame formed along an outer edge of the mesh pattern to support the mesh pattern. The method of claim 1, The electromagnetic shielding film of the plasma display panel further comprises a transparent substrate for supporting the mesh pattern. The method of claim 1, The electromagnetic wave shielding film of the plasma display panel further comprising the transparent conductive film which supports the said mesh pattern and has electroconductivity.