KR100709879B1 - Film filter of a plasma display panel - Google Patents

Abstract

The present invention relates to a film type front filter of a plasma display panel, and in particular, a grounding member suitable for a film type front filter is formed on the front filter to facilitate an electromagnetic shielding layer for blocking electromagnetic waves generated when the plasma display panel is driven. It relates to a film type front filter of a plasma display panel that can be grounded easily.

The film-type front filter according to the present invention is not only thinner and lighter than the glass-type front filter, but also includes a grounding member for grounding on the front surface, which is difficult to ground when the filter is attached to the front surface of the panel. The problem of the type filter has been improved to facilitate easy grounding. In addition, the process is simple and economical by forming a ground member made of a conductive material on the film without forming a separate ground electrode.

Plasma Display Panel, Ground Structure, Film Filter

Description

Film filter of plasma display panel

1 is a perspective view showing a discharge cell structure of a conventional plasma display panel;

2 is a schematic view showing the structure of a glass filter formed on the front surface of a conventional plasma display panel;

Figure 3a is a cross-sectional view schematically showing that the film filter according to the present invention is attached,

3B is a schematic cross-sectional view of FIG. 3A;

3C is an enlarged partial cross-sectional view of A of FIG. 3B;

4 is a flowchart showing a step of forming an electromagnetic shielding film;

5 is a cross-sectional view of a front filter according to an embodiment of the present invention, and

6 is an exploded view schematically illustrating a PDP set with a front filter according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: top plate 20: bottom plate

12Y, 12Z: transparent electrode 13Y, 13Z: bus electrode

14, 22: dielectric layer 16: protective film

24: partition 26: phosphor layer

30, 40, 130: front filter 32, 42: electromagnetic shielding film

36: grounding member

The present invention relates to a film type front filter of a plasma display panel, and in particular, a grounding member suitable for a film type front filter is formed on the front filter to facilitate an electromagnetic shielding layer for blocking electromagnetic waves generated when the plasma display panel is driven. It relates to a film type front filter of a plasma display panel that can be grounded easily.

In general, a plasma display panel (hereinafter referred to as a 'PDP') emits phosphors by 147 nm ultraviolet rays generated during discharge of an inert mixed gas such as He + Xe, Ne + Xe or He + Ne + Xe. The PDP is not only thin and large in size, but also greatly improved in image quality due to the recent development of technology. Since wall charges are accumulated and protect the electrodes from sputtering caused by the discharge, they have advantages of low voltage driving and long life.

1 is a perspective view illustrating a discharge cell structure of a conventional plasma display panel.

Referring to FIG. 1, a three-electrode AC surface discharge type PDP discharge cell includes a scan electrode Y formed on an upper substrate 15 and an address electrode X formed on a sustain electrode Z and a lower substrate 25. It is provided. Each of the scan electrode Y and the sustain electrode Z has a line width smaller than that of the transparent electrodes 12Y and 12Z and the transparent electrodes 12Y and 12Z, and the metal bus electrodes 13Y and 13Z formed at one edge of the transparent electrode. ).

The transparent electrodes 12Y and 12Z are usually formed on the upper substrate 15 by indium tin oxide (ITO). The metal bus electrodes 13Y and 13Z are usually formed of metals such as chromium (Cr) and formed on the transparent electrodes 12Y and 12Z to reduce the voltage drop caused by the transparent electrodes 12Y and 12Z having high resistance. The upper dielectric layer 14 and the passivation layer 16 are stacked on the upper substrate 15 having the scan electrode Y and the sustain electrode Z side by side. In the upper dielectric layer 14, wall charges generated during plasma discharge are accumulated. The protective layer 16 prevents damage to the upper dielectric layer 14 due to sputtering generated during plasma discharge and increases emission efficiency of secondary electrons. As the protective film 16, magnesium oxide (MgO) is usually used.

The lower dielectric layer 22 and the partition wall 24 are formed on the lower substrate 25 on which the address electrode X is formed, and the phosphor layer 26 is coated on the surfaces of the lower dielectric layer 22 and the partition wall 24. The address electrode X is formed in a direction crossing the scan electrode Y and the sustain electrode Z. The partition wall 24 is formed in a stripe or lattice shape to prevent the discharge cells adjacent to the ultraviolet rays and the visible light generated by the discharge from leaking. The phosphor layer 26 is excited by ultraviolet rays generated during plasma discharge to generate visible light of any one of red, green, and blue. An inert mixed gas is injected into the discharge space provided between the upper and lower substrates 15 and 25 and the partition wall 24.

Since the PDP having such a structure implements an image by applying a high voltage and a high frequency for plasma discharge, there is a problem that more electromagnetic waves are emitted to the front of the panel glass than the color cathode ray tube (CRT) or the liquid crystal display panel (LCD). In addition, the plasma display panel emits near infrared rays (NIR) derived from inert gases such as Ne and Xe. Such near infrared rays are very close to the wavelength of the remote controller of home appliances, causing malfunctions. As described above, there is a problem of glare of the user due to external light, and there are general problems such as contrast degradation, which is an image quality characteristic of other display devices.

For this reason, the above-mentioned problem is solved by installing a glass filter or a film filter having a predetermined function on the front surface of the PDP.

The glass filter is spaced apart from the PDP at regular intervals to prevent ultraviolet rays and reduce external reflected light (AR Film), near-infrared (NIR) blocking and color die film (Color-dye film, 220a) to control color, electromagnetic waves Electromagnetic shielding film (EMI Film) for blocking is formed by forming a unit film layer. More specifically, the glass filter is formed on at least one portion of each film having a function such as anti-reflection, color control, electromagnetic shielding, each film is polyethylene tefephthalate (PET) or triacetyl cellulose (TAC) It is attached to the base material (Base Film, 210b, 220b, 230b) of the material such as) to form a unit film layer, each unit film layer is bonded to each other by the adhesive (210c, 220c, 230c).

Looking at the electromagnetic wave shielding film in more detail in the above-described glass filter, the electromagnetic wave shielding film is generally formed by attaching to a substrate of PET or PAC in a mesh type or a conductive film type using a conductive material.

In more detail, as shown in FIG. 2, the electromagnetic wave shielding film layer of the glass filter 200 is connected to a bus bar, which is an Ag-based conductive material formed on the outside of the filter, and has a finger spring gasket 310. And grounded to the metal back cover 350 through the filter support 320 to shield the electromagnetic waves generated when the PDP 100 is driven.

On the other hand, the film filter is excluded from the glass used in the glass filter, the film having a predetermined function including the electromagnetic shielding function to form a filter through a thermal compression or laminating process. Such a film type front filter is lighter in weight and thinner than a front filter including glass. In this case, however, the panel and the filter unit are not formed to be spaced apart at predetermined intervals, and should be attached to the front of the panel, so that the entire panel may be formed without the filter support 320 as shown in FIG. 2. On the other hand, when the grounding electrode is formed on the back of the film type front filter, it is difficult to connect the EMI shielding film with the filter support.

The present invention relates to a film type front filter of a plasma display panel, and in particular, a grounding member suitable for a film type front filter is formed on the front filter to facilitate an electromagnetic shielding layer for blocking electromagnetic waves generated when the plasma display panel is driven. It is to provide a film type front filter of a plasma display panel that can be grounded easily.

In order to achieve the above object, the present invention

A film type front filter comprising an electromagnetic shielding film for shielding electromagnetic waves from a plasma display panel and at least one optical filter film formed on an upper surface of the electromagnetic shielding film.

The electromagnetic wave shielding film has a length in at least one direction greater than the optical filter film, and includes a film type front filter including at least one ground member on an upper surface thereof.

The ground member may be a conductive sponge tape, a conductive paste, a conductive adhesive, a conductive adhesive, or a metal bracket.

The ground member may be connected to the back cover through the filter support or directly.

The optical filter film may be at least one of an antireflection film and a near infrared shielding film.

The front filter may further include a black frame. The black frame is formed to sharpen the outline of the effective screen.

More specifically, the front filter may be formed of a dual structure of the lower layer film formed with the electromagnetic shielding film and the upper layer film formed with the anti-reflection film.

The upper film and the lower film may be made of polyethylene terephthalate (PET), triacetate cellulose (TAC), polycarbonate (PC), and PET.

It is preferable that the said film is a film whose transmittance | permeability is 30 to 90% and haze 1 to 20%.

It is preferable that the antireflection film of the upper layer film has a thickness of 2 to 7 µm and a pencil hardness of 2 to 3H.

The front filter may include an anti-reflection film that prevents light incident from the outside incident to the outside from being reflected back to the outside, an optical characteristic film that lowers the luminance of red and green and increases the luminance of blue among the light incident from the panel; The apparatus may further include a near-infrared shielding layer that prevents the near-infrared (NIR) above the reference from being emitted to the outside so as to shield the near-infrared (NIR) emitted from the panel so as to normally transmit a signal.

The front filter is attached to the display panel by an adhesive or an adhesive, and the adhesive may perform color correction or neon light blocking by adding a pigment / dye as necessary.

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

3A to 3C, the front filter 30 according to the present invention includes an electromagnetic shielding film 32 for shielding electromagnetic waves from a plasma display panel and at least one optical filter film formed on an upper surface of the electromagnetic shielding film 32. A film type front filter 30 including the 34, wherein the electromagnetic wave shielding film 32 is made larger than the optical filter film 34, so that at least one ground portion is exposed to the exposed portion of the electromagnetic wave shielding film 32. The member 36 is formed and directly connected to the back cover or through the filter support 35, thereby making it easier to ground than a conventional filter having a ground electrode formed on the rear surface. Therefore, by attaching the front filter to the front surface of the panel, it is possible to solve the problem of difficulty in grounding by the ground electrode formed on the rear surface of the film type front filter.

The electromagnetic shielding film 32 is made of a conductive mesh, and is generally formed by patterning a mesh metal layer using silver (Ag), copper (Cu), or the like by a photolithography process. In this case, the conductive mesh is provided with holes having a rectangular shape inclined at a bias angle θ for transmitting the light beam, where the bias angle θ depends on the resolution of the PDP.

Referring to FIG. 4, such an electromagnetic shielding film is conventionally provided with a base film wound on a rotating roll (S11 step). The base film wound on the rotary roll is cut to a desired size (step S12). After the mesh metal is deposited on each of the base films cut to a predetermined size, the mesh metal is patterned by a photolithography process and an etching process including an exposure and development process using a photomask (step S 13). In this case, the alignment of the transmissive part and the blocking part of the photomask varies according to the resolution of the PDP. By the patterning process, a mesh film having a conductive mesh formed on the base film is completed (step S 14).

The electromagnetic shielding film 32 may be plated with an oxidation resistant metal to prevent the exposed portion of the electromagnetic shielding film 32 from being oxidized. Specifically, a resist layer is formed on the base film, the conductive metal is plated on the entire surface of the resist, and the oxidation resistant metal is plated on the entire surface of the plated conductive metal layer. Thereafter, a photoresist is applied to the entire surface of the oxidizing metal, and the mesh layer is patterned by photolithography and etching including an image development process by irradiating ultraviolet rays to the film to which the photosensitive resin is applied, thereby forming an upper portion of the mesh layer. In particular, the oxidation-resistant metal coating on the copper mesh layer.

The optical filter film may be at least one of an antireflection film and a near infrared shielding film. That is, referring to FIG. 5, the front filter 40 according to the exemplary embodiment of the present invention includes an anti-reflection film 44, an electromagnetic wave shielding film 42, a near-infrared shielding film 48, and a ground member 46. Here, an adhesive layer (not shown) is formed between the respective films of the film type front filter 40 to bond the films.

The anti-reflection film 44 is formed on the surface of the film type front filter 40 to prevent the light incident from the outside from being reflected back to the outside. In this case, the reflection formed on the surface of the film type front filter 40 The prevention film 44 is formed smaller than the electromagnetic shielding film 42 to provide a space in which the ground member 46 is to be formed. A ground member 46 is formed in the space thus formed (electromagnetic shielding film exposed portion), and is connected to the back cover or directly through the filter support 45 to ground the front film 40. Therefore, even if the film type front filter 40 is attached to a panel (not shown), the electromagnetic shielding film 42 can be easily grounded. The ground member 42 may be a conductive sponge tape, a conductive paste, a conductive adhesive, a conductive adhesive, or a metal bracket. Therefore, the front filter according to the present invention can easily be grounded by forming a ground member made of a conductive material on the film without forming a separate ground electrode, so that the process is simple and economical.

The near infrared shielding film 48 shields the NIR incident from a panel (not shown). That is, the near-infrared shielding film 48 absorbs near-infrared rays of about 700 to 1200 nm wavelength band generated from the PDP to block the radiation to the outside. Accordingly, the near-infrared shielding film 48 allows the control infrared rays (about 947 nm) generated by the remote control or the like to be normally input to the infrared receiver provided in the PDP set without disturbing the near infrared rays. In addition, the near-infrared shielding film 48 includes a color adjusting dye (Color Dye) for increasing color purity together with the near-infrared absorber to increase color purity. The NIR shielding film may be located on the upper or lower surface of the electromagnetic shielding film. When the NIR shielding film is located on the upper surface of the electromagnetic shielding film, the NIR shielding film may be formed smaller than the size of the electromagnetic shielding film in order to form a ground member for grounding the electromagnetic shielding film.

The optical filter film such as the anti-reflection film or the NIR shielding film is preferably formed larger than the effective screen of the PDP.

Many of these thin films are formed on the base film and attached to the top plate of the PDP through an adhesive or an adhesive.

The base film is a thermoplastic resin such as polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), triacetate cellulose (TAC), polyethersulfone (PES), and the like For example, the thickness is preferably in the range of 25 to 150 µm, and the light transmittance is 80% or more, more preferably 90% or more.

Hereinafter, the film type front filter according to the present invention and the PDP in which the filter is used will be described in more detail.

Referring to FIG. 6, the PDP set includes a case 360, a PDP 340 having a printed circuit board 350 (hereinafter referred to as a PCB) and a front filter 330 accommodated in the case 360. And a cover 370 fastened to the case 360 while surrounding the front outer portion of the PDP in which the front filter 330 is formed.

The case 370 protects the PDP 340 accommodated together with the PCB 350 from external shock and blocks electromagnetic waves emitted to the side and the back of the PDP 340. In addition, the case 360 is electrically connected to the film type front filter 330 formed on the front surface of the PDP 340. Specifically, the case 370 is electrically connected to an electromagnetic shielding film (not shown) constituting the film type front filter 330. Accordingly, the case 370 is grounded together with the electromagnetic shielding film (not shown) of the front filter 330 to absorb and discharge electromagnetic waves emitted from the PDP 350 to block the electromagnetic waves from being emitted to the outside.

The above embodiment is an example of the front filter according to the present invention, and those skilled in the art to which the present invention pertains, various modifications are possible using the front filter according to the present invention.

The film-type front filter according to the present invention is not only thinner and lighter than the glass-type front filter, but also includes a grounding member for grounding on the front surface, which is difficult to ground when the filter is attached to the front surface of the panel. The problem of the type filter has been improved to facilitate easy grounding. In addition, the process is simple and economical by forming a ground member made of a conductive material on the film without forming a separate ground electrode.

Claims (9)

An electromagnetic wave shielding film for shielding electromagnetic waves generated from the plasma display panel and at least one optical filter film, wherein the optical filter film is an upper film formed of an anti-reflection film and the electromagnetic shielding film is formed of a double structure of a lower film bonded to the upper film. In the film type front filter, The electromagnetic shielding film has a length in at least one direction greater than the optical filter film, and includes at least one ground member on an upper surface thereof. The front film or the bottom film is a film type front filter, characterized in that the polyethylene terephthalate, triace cellulose or polycarbonate. The method of claim 1, And said ground member is a conductive sponge tape, a conductive paste, a conductive adhesive, a conductive adhesive or a metal bracket. The method according to claim 1 or 2,  And the ground member is connected to the bag cover directly or through a filter support. The method of claim 1, The optical filter film is a film-type front filter, characterized in that further comprises a near-infrared shielding film attached to the upper or lower portion of the electromagnetic shielding film. The method of claim 1, And the front filter further comprises a black frame. delete delete The method of claim 1, The film is a front filter, characterized in that the film is 30 to 90% transmittance, 1 to 20% haze. The method of claim 1, The anti-reflection film is a film-type front filter, characterized in that the thickness 2 ~ 7㎛, pencil hardness 2 ~ 3H.

Images