KR100948766B1 - Light blocking film and optical filter for display apparatus having the same - Google Patents

Abstract

The present invention provides an external light shielding film formed on one surface of the transparent substrate, and an external light shielding pattern consisting of a plurality of external light shielding portions. The external light shielding portion includes a polymer resin and at least one color changeable pigment. The external light shielding part of the external light shielding film is changed in color according to the external heat or the wavelength or intensity of the external light source, thereby improving the contrast ratio of the display device and displaying a specific color on the display screen even when the power is turned off. I can show interior effect.

Description

Light blocking film and optical filter for display apparatus including same

The present invention relates to an external light shielding film and an optical filter for a display device including the same, and more particularly, to improve contrast ratio in bright room, and to change color according to ON / OFF of the display device. The changing external light shielding film and an optical filter for a display device comprising the same.

As the modern society becomes more and more information, photoelectronics related parts and devices are remarkably advanced and spread. Among them, display apparatuses for displaying images are widely used for television apparatuses, monitor apparatuses for personal computers, and the like, and thinning is progressing at the same time as these displays are enlarged.

In general, a plasma display panel (PDP) device is in the spotlight as a next-generation display device because it can satisfy both a larger size and a thinner thickness than a CRT representing a conventional display device. Such a PDP apparatus displays an image using a gas discharge phenomenon, and is excellent in various display capabilities such as display capacity, brightness, contrast, afterimage, viewing angle, and the like. In addition, the PDP device is easier to be enlarged than other display devices, and is considered as a thin light emitting display device having the most suitable characteristics as a high quality digital television in the future.

The PDP device generates a discharge in the gas between the electrodes by a direct current or an alternating current voltage applied to the electrode, and excites the phosphor by the radiation of ultraviolet rays, which emits light.

However, due to its driving characteristics, the PDP device has a high emission amount of electromagnetic waves and near infrared rays, high surface reflection of the phosphor, and color purity of the PDP device due to the orange light emitted from the encapsulated helium (He) or xenon (Xe), which does not reach the cathode ray tube. There is this.

Therefore, electromagnetic waves and near-infrared rays generated in the PDP device may adversely affect the human body and cause malfunction of precision devices such as a wireless telephone or a remote controller. In order to use such a PDP apparatus, it is required to suppress the emission of electromagnetic waves and near-infrared rays emitted from the PDP apparatus below a predetermined value. To this end, in order to shield electromagnetic waves and near infrared rays, and to reduce reflected light and improve color purity, a PDP filter having a function such as electromagnetic shielding, near infrared shielding, light surface reflection prevention and / or color purity improvement is employed.

However, the functional layers employed in the PDP filter have a fixed structure or a fixed material, and thus exhibit optical properties irrespective of external environmental factors. Therefore, various requirements according to the use environment of the display apparatus are not satisfied.

The present invention has been made in view of the above problems, and exhibits an optical property that is fluid according to environmental changes, further improving contrast ratio in bright room conditions, and providing an external light shielding film that can exhibit a specific color even when the power is turned off. .

The present invention also provides an optical filter for display device employing the external light shielding film.

The present invention also provides a method for producing an external light shielding film that can further improve the external light shielding effect and simplify the manufacturing method.

The external light shielding film according to one feature of the present invention is formed on one surface of the transparent substrate and the transparent substrate, and includes an external light shielding pattern composed of a plurality of external light shielding portions. The external light shielding part includes a polymer resin and at least one color changeable pigment.

The color fading pigment may be a photochromic dye whose color is changed according to the wavelength of an external light source or a thermochromic dye whose color is changed depending on an ambient temperature.

The photochromic dye is characterized in that the color change by the light of the wavelength of the ultraviolet region. In addition, the photochromic dye is characterized in that by irradiating light irreversibly discolored black, thereby maintaining a discolored state continuously.

The external light shielding portion has a wedge-shaped cross section and has a stripe shape when viewed in plan view.

An optical filter for a display device according to an aspect of the present invention includes a plurality of functional films and an external light shielding film.

The external light shielding film is formed on one surface of the transparent substrate and the transparent substrate, and includes an external light shielding pattern composed of a plurality of external light shielding portions. The external light shielding part includes a polymer resin and at least one color changeable pigment.

According to one or more exemplary embodiments, a method of manufacturing an external light shielding film may include forming a plurality of wedge-shaped grooves in an ultraviolet curable resin film, filling a resin containing a photochromic dye in the wedge-shaped grooves, and irradiating ultraviolet rays. Steps. The photochromic pigment is irreversibly discolored by ultraviolet light. That is, it is characterized in that it continues to be discolored by ultraviolet light and then discolored.

The external light shielding film according to the present invention may have not only optical properties due to the shape of the external light shielding pattern but also variable optical properties due to the color changeable pigment, and thus various applications are expected.

In addition, the external light shielding film may be applied to a filter for a display device or the like, and may cause a color change according to power ON / OFF of the display device, thereby causing not only optical characteristics but also interior effects.

Above all, the external light shielding film may be suitably used under variable environmental conditions.

In addition, by filling the photochromic dye that is black color change by the light of a specific wavelength together with the light absorbing material, it is possible to increase the content of the black material in the external light shielding film can improve the external light shielding efficiency.

Hereinafter, a PDP apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is an exploded perspective view schematically illustrating a PDP apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the PDP device 100 according to the embodiment of the present invention includes a cover 150 covering an upper portion of the case 110, a driving circuit board 120 accommodated in the case 110, and a gas discharge phenomenon. This is composed of a panel assembly 130 and a PDP filter 140 including a light emitting cell. The PDP filter 140 includes a conductive layer formed of a material having excellent conductivity on the transparent substrate, and the conductive layer is grounded to the case 110 through the cover 150. That is, before the electromagnetic wave generated from the panel assembly 130 reaches the viewer, it is grounded to the cover 150 and the case 110 through the conductive layer of the PDP filter 140.

Hereinafter, the PDP filter will be described in detail.

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

2, the PDP filter 200 is a PDP filter 200 according to an embodiment of the present invention, the filter base 270 and the external light shielding layer is formed on the transparent substrate 210 with various shielding functions, etc. 230.

Here, the filter base 270 is formed by stacking the transparent substrate 210, the antireflection layer 250, or the electromagnetic shielding layer 220 in any order. Hereinafter, in an embodiment of the present invention, the layers corresponding to the electromagnetic shielding function and the antireflection function are separately described as separate ones, but the present invention is not limited thereto. That is, the filter base 270 according to an embodiment of the present invention may be composed of one or more layers, and each layer may have an electromagnetic shielding function, an antireflection function, or a combination thereof. In addition, the filter base 270 may have all of the aforementioned electromagnetic shielding function, antireflection function, or a combination thereof, or may have only one of them.

The external light shielding film 230 is disposed on one surface of the filter base 270. The external light shielding film 230 is disposed on the side of the panel assembly side of the filter base 270, that is, the side opposite to the viewer side when the PDP filter 200 is mounted on the PDP device, but the present invention is not limited thereto. The external light shielding film 230 may be disposed on the other surface of the filter base 270.

The external light shielding film 230 is formed in the support 232, the substrate 234 formed on one surface of the support 232, and the substrate 234 to block external environmental light 320 flowing into the panel assembly from the outside. Pattern 236. The external light shielding pattern 236 includes a plurality of external light shielding units (unit patterns). Hereinafter, a unit pattern constituting the external light shielding pattern 236 will be referred to as an external light shielding part (360 of FIG. 3).

In the present exemplary embodiment, the light blocking pattern 236 is composed of a plurality of wedge-shaped strips (black stripe) spaced apart from each other at regular intervals. In this embodiment, the bottom surface of the wedge-shaped stripe is formed on the substrate to face the panel assembly side.

Here, the substrate 234 on which the light shielding pattern 236 is formed may be formed directly on the filter base 270, but after the substrate 234 is formed on the support 232 as shown in FIG. 2, the filter base 270 is formed. ) Can be combined. The supporter 232 supports the substrate 234 on which the light blocking pattern 236 is formed. In the embodiment illustrated in FIG. 2, one surface of the substrate 234 and the filter base 270 are coupled through the support 232, but the present invention is not limited thereto. That is, since the support 232 serves to support the substrate 234, when the external light shielding film 230 is disposed on the other surface of the filter base 270, the substrate 234 and the filter base 270 may be separated. It may be combined directly. An adhesive layer 240 is formed on one surface of the external light shielding film 230 so that the panel assembly and the filter 200 may be attached. Although the adhesive layer 240 is formed in the filter 200 in the present embodiment, the present invention is not limited thereto.

In addition, the external light shielding unit (unit pattern) has a wedge shape in cross section, and a plurality of stripe patterns (external light shielding units) are formed at regular intervals on one surface of the substrate 234 facing the panel assembly (not shown). The external environment light 320 serves to prevent the inside of the panel assembly from being introduced. At this time, in order to maximize the transmittance of the panel incident light 310, the distance between the external light shielding parts or the width of the external light shielding part may be optimized.

The external light shielding pattern 236, that is, the external light shielding part includes a polymer resin and at least one color changeable resin.

As the polymer resin, an acrylic resin, a silicone resin, a urethane resin, or the like may be used.

The discolorable resin includes a thermochromic dye discolored according to an external temperature or a photochromic dye discolored according to an intensity of external light. Or a photochromic dye that discolors according to a specific wavelength.

Particularly, in the case of the thermochromic dye, the discoloration temperature is preferably about 40 ° C. This is because, in the case of the PDP device, the temperature when it is turned on is about 40 deg. C and when it is turned off, the temperature is lower than 40 deg. That is, in the case of the external light shielding film including a pigment having such a discoloration temperature, when the power is turned off, the desired color may be exhibited to indicate an interior interior effect.

In addition, when the external light shielding part includes a photochromic dye, the photochromic dye is preferably a pigment exhibiting a color in a bright external environment, while displaying a transparent color in a dark place.

Therefore, the degree of light absorption can be effectively changed according to external environmental conditions, so that the contrast ratio can be effectively improved, while in the dark, the transmittance of the image can be increased.

The external light shielding film according to another aspect of the present invention may use a kind that does not return to the original color by reacting with a specific wavelength as the photochromic dye. In particular, a dye that is transparent before light at a specific wavelength is irradiated among the photochromic dyes, but is preferably a dark color after light at a specific wavelength is irradiated. If the dye is not transparent before the color change, the light transmittance may be lowered when the light is irradiated to decrease the color change efficiency of the dye. In addition, when the pigment is bright after the color change, the external light shielding efficiency of the external light shielding film may be reduced.

Photochromic The ultraviolet light is preferably a light having a specific wavelength causing discoloration of the dye. Therefore, as the photochromic dye, a dye whose color is changed by ultraviolet rays such as a photochromic dye may be used, and a diazo dye may be used.

In general, photochromic pigments have a characteristic of changing color upon receiving a specific wavelength and returning to the original color when no light of a specific wavelength is received for a predetermined time. In the present invention, an ultraviolet initiator may be used for the photochromic dye in order to not return to the original color by reacting with a specific wavelength. The UV initiator is an oxide-based or azo-based material that receives radicals to form radicals.

In addition, as described above, when the external light shielding pattern 236 has a wedge shape, not only the optical effect due to the shape of the external light shielding pattern but also the optical effect due to the material forming the external light shielding pattern 236 may be exhibited. It's very efficient.

The color changeable pigment constituting the external light shielding pattern 236 preferably has a content of 0.1 to 100 parts by weight based on 100 parts by weight of the polymer resin solids. If the content of the color change pigment is less than 0.1 parts by weight, the effect is too weak, while if the content of the color change pigment content exceeds 100 parts by weight the polymer resin does not fix the color change pigment, the color change pigment is a polymer It can escape out of the resin.

The content of the discolorable pigment is preferably 1 to 20 parts by weight based on 100 parts by weight of the polymer resin solids.

As the color changeable dye, for example, a spiro-oxazine-based dye can be used. The color changeable dye may be used in plurality, and a photochromic dye and a thermochromic dye may be used simultaneously.

Hereinafter, with reference to Figure 3, it will be described a method for manufacturing the external light shielding film according to an embodiment of the present invention.

The external light shielding film is disposed on the filter base 330, and includes a transparent resin substrate 340 on which a plurality of wedge shaped external light shielding parts 360 are formed. The external light shielding part 360 is filled with the carbon black particles 362 and a resin 364 containing a photochromic dye. In the present embodiment, the shape of the cross section of the external light shielding part 360 is wedge shaped, but the present invention is not limited thereto and may have various shapes such as trapezoidal, rectangular, and semicircular.

After forming an intaglio pattern having a predetermined shape on one surface of the base material 340 of a transparent resin material, a resin containing a light absorbing material and a photochromic dye is filled in the intaglio pattern, and then curing the resin component. To prepare an external light shielding film through the step of.

As a general pattern forming method, a heat press method for pressing a mold to be heated to a thermoplastic resin, a casting method in which a thermoplastic resin composition is injected into a mold and solidified, an injection molding method, or a UV method in which an ultraviolet curable resin composition is injected into a molding mold and UV cured Etc. The pattern may be variously formed by a mold, and generally forms a wedge-shaped pattern. A resin containing colored particles such as carbon black and a conductive material is filled on the transparent substrate on which the pattern is formed by a wiping method and then cured.

When using a photochromic dye is a pigment that is dark to black when the light of the wavelength of the ultraviolet region is irradiated it is preferable to use an ultraviolet curable resin film as the substrate 340. In addition, the photochromic dye should be irreversibly discolored to black under the irradiation of ultraviolet rays. That is, photochromic dyes that remain discolored after being discolored should be used.

The light absorbing material generally uses carbon black, but may be used as long as it is a black material in addition to carbon black. When carbon black is used as the light absorbing material, the carbon black particles have a particle size of about 10 μm and a width of the external light shielding part 360 is about 30 to 40 μm. The resin 364 containing the photochromic dye is filled between the layers. In this case, when the ultraviolet light 390 is irradiated, the photochromic dye is changed to black, so that the photochromic dye-containing resin 364 filled in the space between the carbon black particles 362 in the external light shielding part 360 is It turns black.

Therefore, the effect of filling the black material into the space between the carbon black particles 362 can be obtained, thereby increasing the external light shielding efficiency, thereby improving the contrast ratio in the clear conditions of the display.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

1 is an exploded perspective view schematically showing a PDP apparatus according to an embodiment of the present invention.

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

3 is a cross-sectional view conceptually illustrating an external light shielding film manufactured according to an embodiment of the present invention.

[Description of Major Symbols in Drawing]

100: PDP device 110: case

120: drive circuit board 130: panel assembly

140, 200: PDP filter 150: cover

210: transparent substrate 220: electromagnetic shielding layer

230: external light shielding film 232: support

236: external light shielding pattern 250: antireflection layer

270, 330: filter base 234, 340: base material

310: panel incident light 320: external ambient light

360: external light shield 362: carbon black particles

364: photochromic dye-containing resin 390: ultraviolet light

Claims (15)

Transparent substrates; And An external light shielding film formed on one surface of the transparent substrate and including an external light shielding pattern composed of a plurality of external light shielding parts, The external light shielding part may include at least one thermochromic dye which changes color depending on the polymer resin and the temperature around the pigment or at least one photochromic dye which is irreversibly changed to black by irradiation of light. Exterior light shielding film characterized by the above-mentioned. The method of claim 1, The polymer resin is an external light shielding film comprising at least one of an acrylic resin, a silicone resin and a urethane resin. The method of claim 1, The color fading pigment is an external light shielding film, characterized in that the photochromic dye that changes color depending on the wavelength of the external light source. The method of claim 3, The photochromic dye is an external light shielding film, characterized in that the color change by the light of the wavelength of the ultraviolet region. The method of claim 3, The photochromic dye is an external light shielding film, characterized in that the dye of the diazo series. The method of claim 1, The external light shielding part includes a photochromic dye as a photochromic dye, and further comprises an ultraviolet initiator for forming radicals by ultraviolet rays. The method of claim 6, The ultraviolet light shielding film is an external light shielding film, characterized in that it comprises at least one material selected from oxide-based and azo-based compounds. delete delete The method of claim 1, The external light shielding part comprises 0.1 to 100 parts by weight of a color changeable dye based on 100 parts by weight of the polymer resin solid content. The method of claim 1, The external light shielding film has a wedge-shaped cross section and has a stripe shape when viewed in a plan view. The method of claim 1, The external light shielding film further comprises a support bonded to one surface of the substrate. i) a plurality of functional films; And ii) disposed between at least one layer of the functional films, Transparent substrates; And An optical filter for display device, which is formed on one surface of the transparent substrate and includes an external light shielding film including an external light shielding pattern composed of a plurality of external light shielding parts, The external light shielding portion includes a polymer resin and at least one color changeable pigment. Forming a plurality of wedge-shaped grooves in the ultraviolet curable resin film; Filling the wedge-shaped groove with a resin containing a photochromic dye; And Irradiating ultraviolet rays to the ultraviolet curable resin film; Method for producing an external light shielding film comprising a. The method of claim 14, The photochromic dye is a manufacturing method of an external light shielding film that is irreversibly discolored black by ultraviolet light.

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