KR20080037476A - Filter and plasma display panel employing the same - Google Patents

Abstract

A filter and a plasma display panel are provided to effectively shield an EMI(Electromagnetic Interference) and improve a contrast ratio by mixing a black bead and an EMI shielding material into an external beam shielding portion. A filter includes a transparent substrate(111), an anti-reflection layer(113), a near IR(InfraRed) ray shielding layer(115), and an optical film(120). The transparent substrate passes an inlet visual ray. The anti-reflection layer is formed on one surface of the transparent substrate and prevents a reflection of the external ray. The near IR ray shielding layer is formed on one side of the transparent substrate and blocks an inlet near IR ray. The optical film is formed on at least one surface of the transparent substrate and includes a focusing portion, an external ray shielding portion, plural black beads, and an EMI(ElectroMagnetic Interference) shielding material. The focusing portion focuses the inlet visual ray. The external ray shielding portion is made of a material with a refractive index lower than the focusing portion. The black beads and the EMI shielding material are mixed into the external ray shielding portion.

Description

Filter and plasma display panel employing the same {Filter and Plasma display panel employing the same}

1 is a schematic cross-sectional view showing a conventional plasma display panel (PDP).

Figure 2 is a schematic cross-sectional view showing a conventional filter for PDP.

3 is a schematic cross-sectional view showing a filter according to an embodiment of the present invention.

Figure 4 is a schematic cross-sectional view showing a filter according to another embodiment of the present invention.

5 is a schematic cross-sectional view showing a plasma display panel according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110 ... Filter 111 ... Transparent substrate

113 ... Anti-reflective layer 115 ... Near infrared shielding layer

120 Optical Film 121 Condenser

122 Optical guide 123 Microlenses

125, 126 ... light shield 127 ... black bead

129 Electromagnetic shielding 210 Panel assembly

220 Lower substrate 224 Discharge cell

230.Top board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter and a plasma display panel employing the same. More particularly, the present invention relates to a filter and a plasma display panel employing the same.

In general, a plasma display panel (hereinafter, referred to as a 'PDP') is an apparatus for forming an image by using an electrical discharge. In the PDP, gas discharge occurs between electrodes by an applied direct current or alternating voltage, and phosphors are excited by radiation of ultraviolet rays accompanying the gas discharge process to emit visible light.

The PDP is classified into a counter discharge type PDP and a surface discharge type PDP according to the arrangement of the electrodes. In the opposite discharge type PDP, two pairs of sustain electrodes are arranged on the front substrate and the rear substrate, respectively, and the discharge is formed in the vertical axis direction of the panel. The surface discharge PDP has a structure in which two pairs of sustain electrodes are arranged on the same substrate, and a discharge is formed on one plane of the substrate.

On the other hand, the counter-discharge type PDP has a high luminous efficiency but has a disadvantage in that the phosphor layer is easily deteriorated by plasma. In recent years, the surface-discharge type PDP has become mainstream.

Referring to FIG. 1, a general surface discharge type PDP includes a lower substrate 10 facing each other and an upper substrate 20 coupled thereto.

On the upper surface of the lower substrate 10, a plurality of address electrodes 11 are arranged in a stripe shape, and the address electrodes 11 are embedded by a white first dielectric layer 12. In addition, a plurality of barrier ribs 13 are formed on the top surface of the first dielectric layer 12 to prevent electrical and optical crosstalk between the discharge cells 14. Phosphor layers 15 of red (R), green (G), and blue (B) are respectively coated on the inner surfaces of the discharge cells 14 partitioned by the partitions 13. The discharge cells 14 are filled with a discharge gas in which neon (Ne) gas and a small amount of xenon (Xe) gas, which are generally used as gases for plasma discharge, are mixed.

On the lower surface of the upper substrate 20, stripe-shaped sustain electrodes 21a and 21b orthogonal to the address electrodes 11 are formed in pairs. In addition, bus electrodes 22a and 22b are formed on the bottom surface of each of the sustain electrodes 21a and 21b so as to have a smaller width than the sustain electrodes 21a and 21b. The sustain electrodes 21a and 21b and the bus electrodes 22a and 22b are filled with a transparent second dielectric layer 23, and a protective film 24 is formed on the bottom surface of the second dielectric layer 23.

On the other hand, a plurality of black stripes 30 are formed on the upper surface of the upper substrate 20 to prevent light from flowing into the panel from the outside.

The conventional driving of the PDP having such a configuration is largely divided into driving for address discharge and driving for sustain discharge. The address discharge occurs between the sustain electrode of one of the sustain electrodes 21a and 21b and the address electrode 11, whereby wall charges are formed. The sustain discharge is caused by the potential difference between the sustain electrodes 21a and 21b positioned in the discharge cell 14 in which the wall charges are formed. During the sustain discharge, the phosphor layer 15 of the corresponding discharge cell 14 is excited by ultraviolet rays generated from the discharge gas, and visible light is emitted, and the visible light is emitted through the upper substrate 20 to be recognized by the user. To form an image.

However, in the PDP having the above structure, in the bright condition, that is, the bright room condition, the external light is introduced into the discharge cells 14 of the panel and generated in the discharge cells 14. Light and light introduced from the outside overlap. As a result, the bright room contrast is lowered, resulting in poor display performance of the PDP.

Therefore, in view of the above-described problems of the PDP, conventionally, a filter having a structure as shown in FIG. 2 is employed on the upper substrate.

Referring to FIG. 2, the conventional PDP filter 40 includes a transparent substrate 43 made of transparent glass, a near-infrared shielding layer 45, and a neon light shielding layer sequentially formed on the transparent substrate 43. 47 and the anti-reflective coating on the outer surface and the anti-reflection layer 49 coated with the adhesive material on the inner surface. In addition, an electromagnetic shielding layer 41 is provided below the transparent substrate 43. The electromagnetic wave shielding layer 41 shields electromagnetic waves harmful to the human body, and a transparent conductive film or a conductive mesh having high transmittance and low reflectance characteristics with respect to visible light is mainly used as the material.

When the filter 40 configured as described above is provided on the upper substrate 30 of the PDP, electromagnetic wave shielding and external light may be blocked to improve the display capability of the PDP screen. On the other hand, in the configuration of the filter 40, when forming a five-layer structure is difficult to slim, the manufacturing process is complicated, there is a problem that the manufacturing cost increases.

Accordingly, the present invention has been made in view of the above-described problems, and the present invention provides a filter and a plasma display panel employing the same structure to improve the light condensing efficiency of incident visible light and to improve contrast and shield electromagnetic waves. The purpose is to provide.

In order to achieve the above object, the present invention provides a filter for collecting incident visible light and shielding external light and electromagnetic waves,

A transparent substrate for transmitting incident visible light;

An anti-reflection layer formed on one surface of the transparent substrate to prevent external light reflection;

A near infrared shielding layer formed on one side of the transparent substrate and blocking the incident near infrared rays; It is formed on at least one surface of the transparent substrate, and focuses the incident visible light, and the light collecting portion made of a transparent material having a predetermined refractive index, and disposed adjacent to the light collecting portion to shield external light than the refractive index of the light collecting portion An optical film having an external light shielding portion made of a relatively low refractive index material, a plurality of black beads mixed in the external light shielding portion to absorb external light, and an electromagnetic wave shielding agent mixed in the external light shielding portion to block electromagnetic waves; Characterized in that it comprises a.

In addition, in the plasma display panel according to the present invention, a plurality of discharges in which gas discharge occurs between electrodes by a voltage applied to the electrodes, and phosphors are excited by radiation of ultraviolet rays accompanying the gas discharge, independently emit visible light. A panel assembly comprising a cell; It is provided on the panel assembly, characterized in that it comprises a filter having the above structure.

Hereinafter, a filter according to a preferred embodiment of the present invention and a PDP employing the same will be described in detail with reference to the accompanying drawings.

3 is a schematic cross-sectional view showing a filter according to an embodiment of the present invention.

Referring to the drawings, the filter 110 according to the present invention is employed in a plasma display panel (PDP) or the like including a plurality of discharge cells to discharge independently, and collects the incident visible light and shields external light and electromagnetic waves.

The filter 110 includes a transparent substrate 111, an antireflection layer 113 formed on one surface of the transparent substrate 111 to prevent external light reflection, and an optical formed on at least one surface of the transparent substrate 111. The film 120 and the near-infrared shielding layer 115 to block incident near-infrared rays are included. In FIG. 3, a structure in which an extreme infrared ray shielding layer 115, an optical film 120, a transparent substrate 111, and an antireflection layer 113 are provided in order with respect to a direction in which light travels is illustrated. As a matter of fact, the arrangement order of the above components may be changed.

The transparent substrate 111 is a substrate that transmits incident visible light, and is made of a material such as transparent glass having a predetermined light transmittance.

The outer surface 113a of the anti-reflection layer 113 has a low reflection coating treatment, and an adhesive material is coated on the surface facing the transparent substrate 111. Here, a pigment for color correction may be added to one surface of the anti-reflection layer 113.

The optical film 120 is provided between the transparent substrate 111 and the near infrared shielding layer 115. The optical film 120 includes a light collecting part 121, an external light shielding part 125, a plurality of black beads 127, and an electromagnetic wave shielding agent 129. The condenser 121 condenses and emits incident visible light and is made of a transparent material having a predetermined refractive index. The external light shielding part 125 is disposed adjacent to the light collecting part 121 to shield external light, and is made of a material having a relatively low refractive index than the refractive index of the light collecting part 121. The material itself of the light collecting part 121 and the external light shielding part 125 is well known, and a detailed description thereof will be omitted.

The black bead 127 is mixed in the external light shield 125 to absorb external light. In addition, the electromagnetic shielding agent 129 is mixed in the external light shielding portion 125 to block electromagnetic waves.

The electromagnetic wave shield 129 is composed of a gold-silver (Au-Ag) alloy, a silver-palladium (Ag-Pd) alloy, a silver-platinum (Ag-Pt) alloy, or a carbon nano resin.

In the film according to the present embodiment, the light collecting part 121 preferably includes a plurality of light guides 122. The plurality of light guides 122 are disposed to be spaced apart from each other at predetermined intervals, each of which is provided through an incident surface 122a through which light is incident, an exit surface 122c through which light is emitted, and the incident surface 122a. It includes a guide surface (122b) for the total internal reflection of the incident light to proceed to the exit surface (122c). The area of the incident surface 122a is larger than that of the exit surface 122c. In this case, the external light shield 125 is formed between the plurality of light guides 122 to prevent the external light from flowing.

In the filter 110 according to the exemplary embodiment of the present invention configured as described above, the condensing part 121 includes the incident surface 122a having a different area from the guide surface 122b as shown in FIG. 3. ) And a plurality of light guides 122 having an exit surface 122c. In addition, by concentrating a refractive index between the light concentrator 121 and the external light shield 125, the light condensing efficiency may be improved by condensing incident light using the internal total reflection principle.

In addition, by mixing the black bead 127 and the electromagnetic wave shielding agent 129 in the external light shielding portion 125, there is an advantage that can absorb the external light to improve the clear room contrast and to effectively shield the electromagnetic waves.

4 is a schematic cross-sectional view showing a filter according to another embodiment of the present invention.

Referring to the drawings, the filter 110 according to another embodiment of the present invention is employed in a plasma display panel (PDP) or the like including a plurality of discharge cells 224 to independently discharge, and collects the incident visible light and the external light And shields electromagnetic waves.

The filter includes a transparent substrate 111, an antireflection layer 113 formed on one surface of the transparent substrate 111 to prevent external light reflection, and an optical film 120 formed on at least one surface of the transparent substrate 111. ) And a near infrared shielding layer 115 that blocks incident near infrared rays. Here, the transparent substrate 111, the anti-reflection layer 113 and the near-infrared shielding layer 115 is substantially the same as the configuration of the filter according to an embodiment, and a detailed description thereof will be omitted.

The optical film 120 is provided between the transparent substrate 111 and the near infrared shielding layer 115. The optical film 120 includes a light collecting part 121, an external light shielding part 126, a plurality of black beads 127, and an electromagnetic wave shielding agent 129. The black bead 127 is mixed in the external light shield 126 to absorb external light. In addition, the electromagnetic shielding agent 129 is mixed in the external light shielding portion 126 to block electromagnetic waves. The electromagnetic shielding agent is composed of a gold-silver (Au-Ag) alloy, a silver-palladium (Ag-Pd) alloy, or a silver-platinum (Ag-Pt) alloy, or a carbon nano resin.

In the film 110 according to the present exemplary embodiment, the light collecting part 121 includes a plurality of microlenses 123 for collecting light irradiated from each of the discharge cells, as shown in FIG. 4. Each of the microlenses 123 is provided to correspond to an upper portion of each of the plurality of discharge cells 224, and focuses incident light to improve condensing efficiency.

The external light shield 126 is formed between the plurality of micro lenses 123 to prevent external light from flowing into the discharge cell 224. Here, by mixing the black bead 127 and the electromagnetic wave shielding agent 129 in the external light shielding portion 126, it is possible to absorb external light to improve the clear room contrast and to effectively shield the electromagnetic waves.

Hereinafter, a plasma display panel (PDP) according to an embodiment of the present invention will be described with reference to FIG. 5.

Referring to FIG. 5, the PDP according to the embodiment of the present invention includes a panel assembly 210 and a filter 110 provided on the panel assembly 210.

The panel assembly 210 includes an upper substrate 230 and a lower substrate 220, and a plurality of address electrodes 221 buried by the first dielectric layer 222 is arranged on an upper surface of the lower substrate 220. It is. In addition, a plurality of barrier ribs 223 are formed on the top surface of the first dielectric layer 222 to prevent electrical and optical cross-talk between the discharge cells 224. The phosphor layers 225 of red (R), green (G), and blue (B) are respectively coated on the inner surfaces of the discharge cells 224 partitioned by the partitions 223. The discharge cells 224 are filled with a discharge gas for plasma discharge.

On the lower surface of the upper substrate 230, a sustain electrode 231 and a bus electrode 232 buried by the second dielectric layer 233 are formed. A protective film 234 is formed on the lower surface of the second dielectric layer 233. On the other hand, a plurality of black stripes 240 are formed on the upper surface of the upper substrate 230 in order to prevent light from flowing into the panel from the outside.

The panel assembly configured as described above implements an image through visible light independently emitted from the plurality of discharge cells 224 through driving for address discharge and driving for sustain discharge.

The filter 110 is formed on a surface on which the light of the panel assembly 210 is emitted. The filter 110 collects visible light incident from the panel assembly 210 and shields external light to improve contrast and improve electromagnetic wave. Shield. The filter 110 is formed on the transparent substrate 111, an antireflection layer 113 formed on one surface of the transparent substrate 111 to prevent external light reflection, and formed on at least one surface of the transparent substrate 111. The optical film 120 and the near-infrared shielding layer 115 to block incident near infrared rays are included.

Since the configuration of the filter 110 employed in the PDP according to the embodiment of the present invention is substantially the same as the configuration of the filter according to the embodiments of the present invention shown in FIGS. 3 and 4, a detailed description thereof will be omitted. do.

The PDP configured as described above has the advantage of preventing the external light from entering the discharge cell 224 through the optical film 120 constituting the filter and increasing the condensing efficiency, thereby improving the clear room contrast. In addition, compared with the conventional PDP, there is an advantage that the layer structure of the filter to be used can be simplified, so that the overall slimming is easy and the manufacturing process can be simplified.

The filter configured as described above condenses incident light using a total internal reflection principle or collects light by using a micromirror array with a difference in refractive index between the light collecting part and the external light shielding part in constructing the light collecting part of the optical film. The efficiency can be improved. In addition, by mixing the black bead and the electromagnetic wave shielding agent in the external light shielding portion, there is an advantage that can absorb the external light to improve the clear room contrast and to effectively shield the electromagnetic waves.

In addition, the PDP employing the filter has the advantage of preventing the external light from entering the discharge cell through the optical film constituting the filter and increasing the condensing efficiency, thereby improving the clear room contrast. In addition, compared with the conventional PDP, it is possible to simplify the layer structure of the filter to be used, there is an advantage that it is easy to slim overall, and simplify the manufacturing process.

The above embodiments are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the invention described in the claims below.

Claims (5)

A filter for collecting incident visible light and shielding external light and electromagnetic waves, A transparent substrate for transmitting incident visible light; An anti-reflection layer formed on one surface of the transparent substrate to prevent external light reflection; A near infrared shielding layer formed on one side of the transparent substrate and blocking the incident near infrared rays; It is formed on at least one surface of the transparent substrate, and focuses the incident visible light, and the light collecting portion made of a transparent material having a predetermined refractive index, and disposed adjacent to the light collecting portion to shield external light than the refractive index of the light collecting portion An optical film having an external light shielding portion made of a relatively low refractive index material, a plurality of black beads mixed in the external light shielding portion to absorb external light, and an electromagnetic wave shielding agent mixed in the external light shielding portion to block electromagnetic waves; Filter comprising a. The method of claim 1, The condenser is Spaced apart from each other by a predetermined interval, each of which includes an incident surface on which light is incident, an emitting surface on which light is emitted, and a guide surface for totally internally reflecting light incident through the incident surface to advance to the emitting surface. And a plurality of light guides having a structure in which the area of the incident surface is larger than the area of the emission surface, The external light shielding portion A filter, characterized in that formed between the plurality of light guides to prevent external light from flowing. The method of claim 1, The condenser is A plurality of microlenses for collecting incident light, The external light shielding portion The filter is formed between the plurality of microlenses to prevent external light from flowing. The method of claim 1, The electromagnetic wave shielding agent, A filter comprising a carbon nano resin or an alloy selected from a gold-silver alloy, a silver-palladium alloy, and a silver-platinum alloy. A panel assembly including a plurality of discharge cells in which gas discharge occurs between the electrodes by a voltage applied to the electrodes, and the phosphors are excited by radiation of ultraviolet rays accompanying the gas discharge to independently emit visible light; Visible light provided on the panel assembly, the filter having a structure according to any one of claims 1 to 4, provided at a position corresponding to each of the discharge cells, irradiated from each of the discharge cells Plasma display panel characterized in that it is possible to condense and shield external light and electromagnetic waves.

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