KR20090014735A - Filter and display device thereof - Google Patents

Abstract

A filter and a display apparatus using the same are provided to decrease moire phenomenon which can be generated by being reflected in the filter arranged on a front surface of a panel, after externally incident light is reflected at the panel. A filter(310) for a display apparatus includes an anti glare layer(330). The haze of the anti glare layer is 4 to 60 % and visible light transmission rate is 70 % or more. The anti glare layer is configured to be arranged at an outermost portion of the plurality of layers.

Description

Filter and display device using the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display filter, and more particularly, to a filter for reducing a moire phenomenon caused by interference of light and a display device in which the filter is disposed in front of a panel.

In general, a plasma display panel generates a discharge by applying a predetermined voltage to electrodes provided in a discharge space, and plasma generated during gas discharge excites a phosphor, thereby displaying an image including a character or a graphic. It is advantageous in that it is easy to thin a plane, provides a wide viewing angle up and down, left and right, and realizes full color and high brightness.

In the case of a display device such as the plasma display device, there is a problem in that a moiré phenomenon occurs due to interference of light or overlapping of a regular pattern, thereby degrading the image quality of a display image.

The present invention has been made to solve the above-described problems of the prior art, a filter that reduces the moiré phenomenon that may occur as the light incident from the outside is reflected by the panel and then reflected back in the filter disposed in front of the panel And a display device using the same.

The filter according to the present invention for solving the above technical problem is composed of a plurality of layers are laminated, and comprises an anti glare layer having a haze of 4% to 60% and a visible light transmittance of 70% or more. The antiglare layer is positioned at the outermost of the plurality of layers.

The display device according to the present invention for solving the above technical problem is characterized in that the filter as described above is disposed on the front of the display panel.

According to the filter and the display device using the same according to the present invention configured as described above, by preventing the reflection of the external light reflected by the display panel in the filter disposed on the front, the moiré that can be generated by the interference of the reflected external light ( By reducing the moire phenomenon, the image quality of the display image and the reliability of the display device can be improved.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 13. 1 illustrates a perspective view of an embodiment of a plasma display panel.

As shown in FIG. 1, the plasma display panel includes a scan electrode 11, a sustain electrode 12, a sustain electrode pair formed on the upper substrate 10, and an address electrode 22 formed on the lower substrate 20. It includes.

The sustain electrode pairs 11 and 12 generally include transparent electrodes 11a and 12a and bus electrodes 11b and 12b formed of indium tin oxide (Indi μm-Tin-Oxide; ITO), and the bus electrodes 11b. , 12b) may be formed of a metal such as silver (Ag) or chromium (Cr) or a stack of chromium / copper / chromium (Cr / Cu / Cr) or a stack of chromium / aluminum / chromium (Cr / Al / Cr). have. The bus electrodes 11b and 12b are formed on the transparent electrodes 11a and 12a to serve to reduce voltage drop caused by the transparent electrodes 11a and 12a having high resistance.

Meanwhile, according to the exemplary embodiment of the present invention, the sustain electrode pairs 11 and 12 may not only have a structure in which the transparent electrodes 11a 12a and the bus electrodes 11b and 12b are stacked, but also the buses without the transparent electrodes 11a and 12a. Only the electrodes 11b and 12b may be configured. This structure does not use the transparent electrodes (11a, 12a), there is an advantage that can lower the cost of manufacturing the panel. The bus electrodes 11b and 12b used in this structure may be various materials such as photosensitive materials in addition to the materials listed above.

Between the transparent electrodes 11a and 12a of the scan electrode 11 and the sustain electrode 12 and the bus electrodes 11b and 12b, external light generated outside the upper substrate 10 is absorbed to reduce reflection. A black matrix (BM) may be arranged that functions to block light and to improve the purity and contrast of the upper substrate 10.

The black matrix according to the exemplary embodiment of the present invention is formed on the upper substrate 10, and the first black matrix 15, the transparent electrodes 11a and 12a and the bus electrode are formed at positions overlapping the partition wall 21. The second black matrices 11c and 12c formed between the 11b and 12b may be formed. Here, the first black matrix 15 and the second black matrices 11c and 12c, also referred to as black layers or black electrode layers, may be simultaneously formed and physically connected in the formation process, or may not be simultaneously formed and thus not physically connected. .

In addition, when physically connected and formed, the first black matrix 15 and the second black matrix 11c and 12c may be formed of the same material, but may be formed of different materials when they are formed separately.

Since the bus electrodes 11b and 12b or the partition wall 21 have a dark color, the light blocking function absorbs external light generated from the outside and reduces reflection, such as the black matrix, thereby improving contrast. have. Alternatively, a specific member formed on the upper substrate 10, for example, the dielectric layer 13 and the specific member formed on the lower substrate 20, for example, the partition wall 21, have a complementary color relationship with each other, so that they overlap when viewed from the front of the panel. It can also function as the black matrix by making the portion appear closer to black.

The upper dielectric layer 13 and the passivation layer 14 are stacked on the upper substrate 10 having the scan electrode 11 and the sustain electrode 12 side by side. Charged particles generated by the discharge are accumulated in the upper dielectric layer 13, and the protective electrode pairs 11 and 12 may be protected. The protective film 14 protects the upper dielectric layer 13 from sputtering of charged particles generated during gas discharge, and increases emission efficiency of secondary electrons.

In addition, the address electrode 22 is formed in a direction crossing the scan electrode 11 and the sustain electrode 12. In addition, a lower dielectric layer 24 and a partition wall 21 are formed on the lower substrate 20 on which the address electrode 22 is formed.

In addition, the phosphor layer 23 is formed on the surfaces of the lower dielectric layer 24 and the partition wall 21. The partition wall 21 has a vertical partition wall 21a and a horizontal partition wall 21b formed in a closed shape, and physically distinguishes the discharge cells, and prevents ultraviolet rays and visible light generated by the discharge from leaking into adjacent discharge cells. have.

Referring to FIG. 1, it is preferable that a filter 100 is formed on a front surface of the plasma display panel according to the present invention, and the filter 100 includes a bright contrast ratio improving sheet, an external light blocking sheet, and an anti-reflection (AR) filter. ), A NIR (Near Infrared) shielding sheet, an Electromagnetic Interference (EMI) shielding sheet, a diffusion sheet, an optical sheet, an anti glare layer, and the like.

In an embodiment of the present invention, not only the structure of the partition wall 21 illustrated in FIG. 1, but also the structure of the partition wall 21 having various shapes may be possible. For example, a channel in which a channel usable as an exhaust passage is formed in at least one of the differential partition structure, the vertical partition 21a, or the horizontal partition 21b having different heights of the vertical partition 21a and the horizontal partition 21b. A grooved partition structure having a groove formed in at least one of the type partition wall structure, the vertical partition wall 21a, or the horizontal partition wall 21b may be possible.

Here, in the case of the differential partition wall structure, the height of the horizontal partition wall 21b is more preferable, and in the case of the channel partition wall structure or the groove partition wall structure, it is preferable that a channel is formed or the groove is formed in the horizontal partition wall 21b. something to do.

Meanwhile, in one embodiment of the present invention, although the R, G and B discharge cells are shown and described as being arranged on the same line, it may be arranged in other shapes. For example, a Delta type arrangement in which R, G, and B discharge cells are arranged in a triangular shape may be possible. In addition, the shape of the discharge cell may be not only rectangular, but also various polygonal shapes such as a pentagon and a hexagon.

In addition, the phosphor layer 23 emits light by ultraviolet rays generated during gas discharge to generate visible light of any one of red (R), green (G), and blue (B). Here, an inert mixed gas such as He + Xe, Ne + Xe and He + Ne + Xe for discharging is injected into the discharge space provided between the upper / lower substrates 10 and 20 and the partition wall 21.

2 is a cross-sectional view illustrating a structure of a filter disposed on a front surface of a display panel, and the filter may include an AR / NIR sheet 210, an optical characteristic sheet 220, and an EMI shield sheet 230.

Referring to FIG. 2, the AR / NIR sheet 210 has a function of reducing glare by preventing reflection of light incident from the outside on the front surface of the base sheet 212 made of a transparent plastic material. A reflection layer 211 is attached, and a NIR (Near Infrared) shield sheet 213 is attached to the rear to shield the near infrared rays emitted from the panel so that signals transmitted using infrared rays such as a remote controller can be normally transmitted. do.

The optical sheet 220 improves the color temperature and luminance characteristics of the light incident from the panel, and the optical layer 221 formed of a predetermined dye and an adhesive is laminated on the front or rear of the base sheet 222 made of a transparent plastic material. do.

EMI shielding sheet 230 is a shielding sheet 230 is attached to the front of the base sheet 232 made of a transparent plastic material to shield the electromagnetic interference (EMI) to prevent the EMI radiated from the panel to be emitted to the outside. In this case, the shielding sheet 231 is generally formed of a mesh structure using a conductive material, and an invalid display of the shielding sheet 231 in which an image is not displayed in order to make the ground smooth. The region is coated with a conductive material as a whole.

The adhesive 240 forms a layer between the AR / NIR sheet 210, the optical characteristic sheet 220, and the EMI shielding sheet 230 as described above, so that the sheets 210, 220, 230, and the filters are respectively formed. Should be firmly attached to the front of the panel. In addition, it is preferable that the material of the base sheet included between the sheets 210, 220, and 230 be substantially the same material in consideration of the ease of making the filter.

On the other hand, in Figure 2 is laminated in the order of 210, 220, 230, the stacking order of each sheet may be laminated differently by those skilled in the art. In addition, at least one of the illustrated sheets 210, 220, 230 may be omitted.

In addition, at least one basesheet of the basesheets shown in FIG. 2 may be omitted, and any one of the basesheets may be made of hard glass, not plastic, to improve the function of protecting the panel. Can be. The glass is preferably formed spaced apart from the panel at a predetermined interval.

The filter may further include a diffusion sheet (not shown) that serves to diffuse the incident light so that the light maintains uniform brightness. Accordingly, the diffusion sheet (not shown) can spread the light emitted from the panel uniformly to widen the vertical viewing angle of the display screen, and conceal the pattern formed on the EMI shielding sheet 230 or the like. In addition, the diffusion sheet (not shown) can collect light in a direction corresponding to the vertical viewing angle, make the front luminance uniform, and improve the antistatic property.

As the diffusion sheet (not shown), a transmissive or reflective diffusion film or the like may be used. In general, the diffusion sheet may have a form in which small glass beads are mixed in a base sheet of a polymer material. In addition, high purity acrylic resin (PMMA) may be used as a base sheet of the diffusion sheet (not shown), and when the high purity acrylic resin (PMMA) is used, the sheet is thick but has good heat resistance and is used for a large display device having high heat generation. Can be.

3 is a schematic cross-sectional view of a structure of a display panel and a filter disposed in front of the panel.

Referring to FIG. 3, light incident from the outside (indicated by a solid line) may pass through a filter 310 in which a plurality of functional layers are stacked, and the external light passing through the filter 310 may pass through the display panel 300. Can be reflected.

A portion of the external light reflected by the display panel 300 may be reflected back from any one layer 320 of the plurality of layers of the filter 310. For example, a part of the external light reflected by the display panel 300 may be reflected by a base sheet made of a glass layer included in the filter 310 or a polyethylene terephthalate (PET).

As described above, the external lights A, B, and C, which are reflected and emitted to the user side, may interfere with each other, thereby causing a moiré phenomenon. The moiré phenomenon generated by the interference of the reflected external light as described above may occur even while power is not applied to the display device.

Figure 4 shows in schematic cross section a structure of a filter comprising an anti glare layer according to the invention.

Referring to FIG. 4, the filter according to the present invention preferably includes an antiglare layer 330 which prevents external light reflected from the panel from being reflected back from the filter 310.

The anti-glare layer 330 may scatter or diffuse the external light reflected from the panel or generate a destructive interference between the reflected external light, thereby preventing the external light reflected from the panel from being reflected back by the filter 310. .

As shown in FIG. 4, the anti-glare layer 330 is preferably formed at the bottom of the filter, that is, the side of the filter adjacent to the panel 300 on both sides of the filter. It may be formed between the layers.

In order to prevent the external light reflected from the panel from being reflected back by the filter 310 to reduce the occurrence of moiré phenomena, the haze of the anti-glare layer 330 is preferably 4% or more in consideration of the light reflectance of the panel. Do. By forming irregularities on the surface of the antiglare layer 330, the haze of the antiglare layer 330 can be made 4% or more.

However, when the haze of the anti-glare layer 330 becomes too high, the visible light transmittance of the anti-glare layer 330 decreases, thereby lowering the brightness of the display image. In order to reduce the moiré phenomena caused by interference of reflected external light without significantly reducing the brightness of the display image, the visible light transmittance of the antiglare layer 330 is preferably 70% or more, and in order to display a high quality image, the antiglare layer As for the visible light transmittance of (330), it is more preferable that it is 90% or more.

Table 1 below shows the results of measuring the visible light transmittance according to the haze value of the anti-glare layer 330, and FIG. 5 shows the measurement results in a graph.

Referring to Table 1 and FIG. 5, it can be seen that the visible light transmittance of the antiglare layer 330 decreases as the haze value of the antiglare layer 330 increases, and the haze of the antiglare layer 330 is reduced. It can be seen that when the haze exceeds 60%, the visible light transmittance rapidly decreases to 70% or less.

Therefore, in order to maintain the visible light transmittance of the anti-glare layer 330 at 70% or more to simultaneously improve the brightness and moiré of the display image, the haze of the anti-glare layer 330 is preferably 4% to 60%. Do.

Table 2 below shows the results of measuring the visible light transmittance according to the haze value of the anti-glare layer 330 formed on the glass, and FIG. 5 illustrates the measurement result in a graph.

Referring to Table 2 and FIG. 6, when the haze of the anti-glare layer 330 formed on the glass exceeds 30%, the visible light transmittance rapidly decreases to 70% or less.

Therefore, when the anti-glare layer 330 is formed on the glass, the haze of the anti-glare layer 330 is preferably 4% to 30%.

7 and 8 illustrate embodiments of the structure of the anti-glare layer according to the present invention in cross-sectional view, wherein the anti-glare layer may have a structure in which the first layer 331 and the second layer 332 are stacked. have.

Referring to FIG. 7, the first layer 331 is a layer having transparency to visible light, and a resin of a transparent material such as polyethylene terephtalate (PET), polymethly methacrylate (PMMA), or tri-acetyl-cellulose (TAC) is used. Alternatively, a compound or glass of the transparent resins may be used.

In order that the external light F reflected by the first layer 331 and the external light reflected by the second layer 332 do not cancel each other and cause re-reflection in the panel, the second layer 332 is formed of the first layer 331. It is desirable to have a refractive index smaller than).

Equation 1 below shows a condition for causing external interferences D and F reflected from the first and second layers 331 and 332 to cause destructive interference.

In Equation 1, n ₁ is a refractive index of a layer positioned between the second layer 332 and the panel 300, n ₂ is a refractive index of the second layer 332, and n ₃ is a first layer 331. Index of refraction). In addition, d is the thickness of the second layer 332, and λ means the wavelength of the external light. Assuming that the layer located between the second layer 332 and the panel 300 is an air layer, n ₁ may be 1.

As described above, when the first layer 331 is a transparent layer made of PET, PMMA, TAC, glass, or the like, the refractive index n ₃ of the first layer 331 may be about 1.2 to 1.8.

According to the above-described range of n ₁ , n ₃ and Equation 1, when the refractive index n ₂ of the second layer 332 is 1.1 to 1.35, external light F reflected by the first layer 331 is reflected. ) And the external light reflected from the second layer 332 may cause mutual interference and may not be reflected back from the panel, thereby reducing the moiré phenomenon caused by the interference of the external light.

Accordingly, in order for external light reflected from the first and second layers 331 and 332 to cause destructive interference, the refractive index difference between the first and second layers 331 and 332 may be 0.1 to 0.7, and the second layer 332 The refractive index of may be 0.74 times to 0.91 times the refractive index of the first layer 331.

In addition, considering that the wavelength of the visible light is 380 nm to 770 nm, when the thickness d of the second layer 332 is 78 nm to 158 nm, the external light F reflected by the first layer 331 and External light reflected from the second layer 332 may cause destructive interference with each other and may not be reflected back from the panel.

As illustrated in FIG. 7, the second layer 332 having a small refractive index may be formed on a lower surface of the first layer 331, that is, on a surface of both surfaces of the first layer 331 adjacent to the panel 300.

Referring to FIG. 8, the second layer 333 having a small refractive index may be formed on an upper side of the first layer 331, that is, a surface far from the panel 300 among both surfaces of the first layer 331.

9 is a cross-sectional view of a first embodiment of the structure of a filter including an antiglare layer according to the present invention.

Referring to FIG. 9, the filter according to the present invention may include an AR / NIR sheet 210, an optical characteristic sheet 220, an EMI shielding sheet 230, and an antiglare layer 330. The anti-glare layer 330 may be formed at the lowermost layer of the filter.

10 shows in cross section a second embodiment of the structure of a filter comprising an antiglare layer according to the invention.

Referring to FIG. 10, in order to effectively block external light so that the black image of the display panel may be darker, the display filter further includes an external light blocking sheet 250 including a plurality of pattern portions that absorb external light. can do.

As shown in FIG. 10, the anti-glare layer 330 according to the present invention may be formed between the external light blocking sheet 250 and the panel to prevent re-reflection of external light reflected from the panel.

11 is a cross-sectional view of an embodiment of a structure of an external light blocking sheet, and the external light blocking sheet includes a base part 251 and a plurality of pattern parts 252.

Referring to FIG. 11, the base part 251 is preferably made of a transparent plastic material, for example, a resin-based material formed by UV curing, so as to transmit light smoothly. In order to increase the protection effect, a rigid glass material may be used.

The pattern portion 252 may have a triangular shape, or may have other shapes. The pattern part 252 is formed of a material of darker color than the base part 251, and is preferably made of a black material. For example, the pattern unit 252 may include carbon-based light absorbing particles or may apply a black dye to maximize the effect of absorbing external light. Hereinafter, the wider of the upper and lower ends of the pattern unit 252 is defined as the lower end of the pattern unit 252.

The lower end of the pattern portion 252 may be disposed on the panel side, and the upper end of the pattern portion 252 may be disposed on the observer side where external light is incident. In addition, in contrast to the above arrangement, the lower end of the pattern portion 252 may be disposed toward the observer side, and the upper end of the pattern portion 252 may be disposed on the panel side.

Since the external light source is generally located above the panel, external light (indicated by a solid line) is incident on the panel at an angle from the upper side to be absorbed by the pattern portion 252.

In order to absorb and block external light and totally reflect the visible light emitted from the panel to increase the reflectance of the panel light, the refractive index of the pattern portion 252, at least the portion of the pattern portion 252 in contact with the base portion 251. Can be made smaller than the refractive index of the base portion 251.

By Snell's law, external light (indicated by a solid line) incident at an angle is refracted and absorbed into the pattern portion 252 having a refractive index smaller than that of the base portion 251. External light refracted into the pattern portion 252 may be absorbed by the light absorbing particles. In addition, the light emitted from the panel may be totally reflected on the inclined surface of the pattern portion 252 and reflected to the outside that is the observer side. As a result, the clear room contrast of the display image may be improved.

In order to maximize absorption of external light and total reflection of panel light in consideration of the incident angle of external light, the refractive index of the pattern portion 252 is preferably 0.3 times or more and less than 1 times the refractive index of the base portion 251. In order to maximize the total reflection of the light emitted from the panel on the inclined surface of the pattern portion 252, considering the vertical viewing angle of the plasma display panel, the refractive index of the pattern portion 252 is 0.3 times to 0.8 of the refractive index of the base portion 251. It is preferable to be a ship.

In addition, the ghost phenomenon may be reduced by making the refractive index of the pattern portion 252 larger than the refractive index of the base portion 251 so that light emitted obliquely from the panel may be absorbed into the pattern portion 252. In order to sufficiently absorb the panel light incident at an angle to the pattern portion 252 to prevent ghosting, the difference between the refractive index of the pattern portion 252 and the refractive index of the base portion 251 is preferably 0.05 or more.

When the refractive index of the pattern portion 252 is larger than the refractive index of the base portion 251, the transmittance and the clear room contrast of visible light may be reduced, so that the pattern portion may be prevented while preventing the ghost phenomenon and greatly reducing the transmittance of the visible light. The difference between the refractive index of 252 and the refractive index of the base portion 251 is preferably 0.05 to 0.3. In addition, in order to prevent the ghost phenomenon and maintain the clear yarn coat of the panel at an appropriate level, the refractive index of the pattern portion 252 is preferably 1.0 times to 1.3 times the refractive index of the base portion 251.

12 is a cross-sectional view of a third embodiment of a structure of a filter comprising an anti glare layer according to the present invention, wherein the filter according to the present invention comprises a plurality of lenses that focus visible light emitted from the panel. It may further include a bright room contrast ratio improvement sheet 260 including the portions.

As shown in FIG. 12, the anti-glare layer 330 according to the present invention is formed between the bright room contrast ratio improvement sheet 260 and the panel so that external light reflected from the panel is lowered from the bright room contrast ratio enhancement sheet 260. It can prevent re-reflection.

13 to 15 illustrate the structure of the brightness contrast ratio enhancement sheet in cross-section, and the brightness contrast ratio enhancement sheet includes a base layer 410 and a plurality of lens units 420, 430, 440, 450, and 460. Can be.

The base layer 410 is preferably made of a transparent plastic material, for example, a resin-based material formed by an ultraviolet (UV) curing method so that light can be transmitted through smoothly, and enhances the effect of protecting the front surface of the panel. For this purpose, a rigid glass material may be used.

Referring to FIG. 13, the refractive index of the lens parts 420, 430, 440, 450, and 460, and the refractive index of at least a portion of the lens parts 420, 430, 440, 450, and 460 contacting the base layer 410 may be determined by the base layer. It is preferable that the refractive index is greater than 410.

The visible light emitted from the panel 400 may be refracted at a portion where the lens parts 420, 430, 440, 450, and 460 and the base layer 410 contact and be focused toward the user.

Referring to FIG. 14, since the refractive index of the lens unit 470 is greater than the refractive index of the base layer 410, the light emitted from the panel 400 by Snell's law may have an angle larger than the incident angle θ1. θ2) is refracted at the portion where the lens portion 470 and the base layer 410 contact. Therefore, as shown in FIG. 14, the light emitted from the panel 400 may be focused on the user side, which is the front of the panel, thereby improving contrast and image quality of the display image.

In order for the light emitted from the panel 400 to be refracted in the front direction of the panel at the portion where the lens part 470 and the base layer 410 contact, the refractive index of the lens part 470 is determined based on the incident angle of the panel light. It is preferable that the refractive index of 410 is 1.01 to 1.9 times.

In addition, in order to improve the light collecting efficiency of the light emitted from the panel 400 and to prevent the panel light from being reflected at the bottom of the lens unit 470 and the luminance of the display image is lowered, the refractive index of the lens unit 470 may be reduced by the base layer ( 410 may be from 1.03 times to 1.65 times the refractive index.

In order to improve the clear contrast of the display image and to prevent the brightness of the image from being lowered, the visible light transmittance of the lens unit 470 is preferably 40% or more.

In one embodiment of the manufacturing method of the bright room contrast ratio improvement sheet, after etching the base layer 410 made of a UV resin or the like in the shape of the lens unit (420, 430, 440, 450, 460), By filling a material having a refractive index larger than that of the base layer 410, a bright room contrast ratio improving sheet may be manufactured.

Referring to FIG. 15, when the distance c between two adjacent lens parts 520 and 530 is 5 μm to 100 μm, the aperture ratio for improving the luminance of the display image is secured and the light condensing efficiency of the panel light is improved. You can.

Table 3 below shows the results of measuring the brightness and the maximum viewing angle of the display image according to the change of the angle Φ between two straight lines connecting the upper and lower ends of the lens unit 520.

In Table 3, the brightness of the display image is a value based on the brightness when the angle Φ of the lens unit is 90 degrees. Referring to Table 3, when the angle Φ of the lens unit is 90 degrees, the brightness and the maximum viewing angle of the display image have a maximum value and decrease as the distance is far from 90 degrees.

According to the measurement result, when the brightness contrast ratio enhancement sheet is disposed in front of the panel, the brightness of the display image may be improved up to about 1.25 times. Therefore, in order to condense the panel light to improve the clear contrast of the display image and not reduce the brightness of the image, the brightness of the display image is preferably in the range of 0.8 times or more of the maximum value.

When the angle Φ of the lens unit 520 is 30 degrees to 150 degrees, the brightness of the display image is 0.8 times or more of the maximum value, thereby improving the clear contrast of the display image and not reducing the brightness of the image. have.

In addition, when the angle Φ is 30 degrees to 150 degrees, the height b of the lens portion 510 is 0.13 times to 1.87 times the lower width a. Therefore, when the height b of the lens unit 510 is 0.13 times to 1.87 times the lower width a, the clear contrast can be improved without lowering the luminance of the display image.

Also, in general, when the maximum viewing angle of the display panel is 150 degrees or less, the user may feel discomfort in viewing, and therefore, the angle Φ of the lens unit 520 is more preferably 60 to 120 degrees.

When the angle Φ is 60 degrees to 120 degrees, the height b of the lens unit 510 is 0.29 times to 0.87 times the lower width a. Therefore, when the height b of the lens unit 510 is 0.29 times to 0.87 times the lower width a, the brightness and the clear contrast of the display image may be improved while maintaining the maximum viewing angle of the panel at 150 degrees or more.

Considering the pixel size of the display panel and the angle at which the panel light is emitted, the condensing efficiency of the panel light can be improved when the lower width a of the lens unit 510 is 40 μm to 60 μm, thereby improving the display image. In order not to lower the luminance, the height b of the lens unit 510 is preferably 16 μm to 36 μm.

In addition, in order for the light emitted from the panel to be focused in the front direction of the panel, the distance between the focus of the lens unit 510 and the panel is 3 mm or less in consideration of the size of the lens unit as described above. Also, considering the relationship between the height of the lens unit 510 and the bottom width as described above, when the distance between the lens unit 510 and the panel is 4 mm or less, the light emitted from the panel is focused in the front direction of the panel. Can be.

The light contrast ratio enhancement sheet may have an antireflection layer (not shown) made of a material having a refractive index smaller than that of the lens units 510, 520, and 530 at the bottom of the lens units 510, 520, and 530.

An antireflection layer (not shown) having a refractive index smaller than that of the lens units 510, 520, and 530 is formed at the bottom of the lens units 510, 520, and 530, so that light emitted from the panel is transferred to the lens units 510, 520, and 530. It is possible to prevent the reflection from the bottom of the. Therefore, the brightness of the display image can be improved.

The anti-reflection layer (not shown) is preferably formed between the anti-glare layer and the lens portion of the bright room contrast ratio improving sheet according to the present invention.

The filter including the anti-glare layer according to the present invention as described above may be formed as a film filter type to be attached to the panel using adhesion, otherwise the glass filter type is spaced apart from the panel including glass Can also be formed.

In the above, the filter according to the present invention has been described as an embodiment, which is disposed on the front surface of the plasma display panel. It can be used for various display devices.

Although a preferred embodiment of the present invention has been described in detail above, those skilled in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made to the branches. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

1 is a perspective view illustrating an embodiment of a structure of a plasma display panel.

2 is a cross-sectional view illustrating a structure of a filter disposed on a front surface of a display panel.

3 is a cross-sectional view briefly illustrating a structure of a display panel and a filter disposed in front of the panel.

4 is a cross-sectional view illustrating a schematic structure of a filter including an anti glare layer according to the present invention.

5 and 6 are graphs showing the results of measuring the visible light transmittance of the anti glare layer according to the haze of the anti glare layer.

7 and 8 are cross-sectional views showing embodiments of the structure of the anti-glare layer according to the present invention.

9 is a cross-sectional view showing a first embodiment of the structure of a filter including an anti glare layer according to the present invention.

10 is a cross-sectional view showing a second embodiment of the structure of a filter including an anti glare layer according to the present invention.

11 is a cross-sectional view showing an embodiment of the structure of an external light blocking sheet.

12 is a cross-sectional view showing a third embodiment of the structure of a filter including an anti glare layer according to the present invention.

It is sectional drawing which shows schematic structure of a bright room contrast ratio improvement sheet.

It is sectional drawing for demonstrating the light condensing function of a bright room contrast ratio improvement sheet.

15 is a cross-sectional view showing an embodiment of a structure of a bright room contrast ratio improving sheet.

Claims (12)

In the display filter composed of a plurality of layers are stacked, And an anti glare layer having a haze of 4% to 60% and a visible light transmittance of 70% or more, wherein the antiglare layer is located at the outermost of the plurality of layers. The method of claim 1, The anti-glare layer is laminated on the glass, the filter characterized in that the haze of the anti-glare layer is 4% to 30%. The method of claim 1, The visible light transmittance of the anti-glare layer is a filter, characterized in that 90% or more. The method of claim 1, wherein the anti-glare layer Transparent layer; And a first layer laminated on the transparent layer and having a lower refractive index than the transparent layer. The method of claim 4, wherein The refractive index of the first layer is a filter, characterized in that 1.1 to 1.35. The method of claim 4, wherein The refractive index of the first layer is a filter, characterized in that 0.74 times to 0.91 times the refractive index of the transparent layer. The method of claim 4, wherein The refractive index difference between the first layer and the transparent layer is a filter, characterized in that 0.05 to 0.5. The method of claim 1, The thickness of the first layer is a filter, characterized in that 78nm to 158nm. The method of claim 1, Base layer; And At least a portion in contact with the base layer has a refractive index greater than that of the base layer, and further comprising a brightness contrast ratio enhancement sheet having a first layer comprising a plurality of lens portions having a thickness of a central portion greater than a thickness of an outer portion. Featured filter. The method of claim 9, And the antiglare layer is positioned between the bright contrast ratio enhancement sheet and the display panel. The method of claim 1, An AR sheet for preventing reflection of external light; A NIR shielding sheet for shielding near infrared rays; And And at least one of an EMI shielding sheet for shielding electromagnetic waves. The display apparatus in which the filter in any one of Claims 1-10 is arrange | positioned in the front of a display panel.

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