KR20080042299A - External light blocking film for display apparatus and filter for display apparatus having the same - Google Patents

Abstract

An external light blocking film for a display device and a filter for the display apparatus having the same are provided to increase a contrast ratio of a bright room by making a vertical section of an external light blocking unit in at least two shapes in consideration of the incidence angle changed according to the incidence position of the external light on a display screen. An external light blocking film(200) for a display device is composed of a base(220) made of transparent resin and an external light blocking pattern formed on one surface of the base and provided with a plurality of external light blocking units(240). The section of the external light blocking unit is formed in at least two kinds of shapes. The external light blocking units are aligned on one surface of the base in parallel. The external light blocking unit comprises a bottom surface exposed outside the base and inclined surfaces(242,244) extended from the bottom surface. The inclined surfaces have the predetermined inclination angle for a normal line of the bottom surface.

Description

External light blocking film for display device and filter for display device including same {External light blocking film for display apparatus and filter for display apparatus having the same}

1 is a cross-sectional view showing a PDP filter including an external light shielding film for a display device according to an embodiment of the present invention.

2 is a perspective view illustrating an external light shielding film for a display device according to an embodiment of the present invention.

3 is a view illustrating an embodiment to which the present invention is applied when there is an indoor lighting device, in which external ambient light is incident on a vertical section obtained by cutting the exterior light shielding film of FIG. 2 along a line II ′. It is shown conceptually.

[Description of Major Symbols in Drawing]

100: filter for display device 110: filter base

112: transparent substrate 114: electromagnetic shielding film

116: anti-radiation film 130: external light shielding film

132: base material 134: external light shielding pattern

150: support 170: color correction layer

200: external light shielding film 220: base material

240: external light shielding portion 242: first inclined surface

244: second slope 252: first long side

254: second long side 300: indoor lighting device

The present invention relates to an external light shielding film for a display device and a filter for a display device including the same, and more particularly, to an external light shielding film for a display device that can improve contrast ratios in a bright room. And it relates to a filter for a display device comprising the same.

In general, a plasma display panel (PDP) device is in the spotlight as a next-generation display device because it can satisfy both an enlargement and a thinning at the same time as a cathode ray tube (CRT) representing a conventional display device. The 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 voltage applied to the electrode, and emits light by exciting the phosphor by the radiation of ultraviolet 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.

Such a PDP device is composed of a panel assembly including a discharge cell in which gas discharge occurs, and a PDP filter shielding electromagnetic waves and near infrared rays. Since the PDP filter is mounted on the front of the panel assembly, transparency must be satisfied at the same time.

In the PDP device according to the related art, external environment light may be introduced into the panel assembly through the PDP filter under bright conditions, that is, bright room conditions. In this case, an overlap of incident light generated in the discharge cell in the panel assembly and external environmental light introduced through the PDP filter from the outside occurs. As a result, the contrast ratio is lowered in the bright room condition, resulting in poor display capability of the PDP device.

To improve this, there is a method of using an external light shielding film that absorbs external environmental light as part of the PDP filter. However, when the external light shielding pattern filled with the light absorber is formed in the external light shielding film, the light emitted from the panel assembly is partially absorbed, resulting in a decrease in the luminance of the PDP device and a narrow viewing angle. Therefore, it is required to effectively shield external ambient light to increase the contrast ratio, and to increase the brightness and viewing angle of the display screen.

The conventional external light shielding pattern has a stripe shape in which a plurality of external light shielding parts are arranged parallel to the long side of the display screen. A light absorber is filled in the grooves regularly dug into a predetermined shape while forming an inclined surface into the base of the external light shielding film. However, in general, when the PDP device is used indoors, the external ambient light incident from the indoor lighting device varies the incident angle at each point of the display screen. Therefore, there is a limit to the absorption efficiency of external light having various incident angles as the external light shielding pattern having a uniform shape. In addition, when increasing the concentration of the light absorber filled in the external light shielding pattern or increasing the depth of the groove of the external light shielding pattern in order to increase the light absorption efficiency, in the manufacturing method of the conventional general light shielding film, the filling of the light absorber There is a problem of this incompleteness.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a variety of cross-sectional shapes of the external light shielding pattern without increasing the concentration of the light absorber and the depth of the external light shielding pattern, thereby improving contrast ratio and visibility in the bright room conditions of the display device. It provides an external light shielding film that can be made.

This invention also provides the filter for display apparatus which employ | adopted the said external light shielding film.

The external light shielding film according to an aspect of the present invention includes a substrate made of a transparent resin material, and an external light shielding pattern formed on one surface of the substrate and having a plurality of external light shielding portions. The shape of the vertical cross section of the said external light shielding part is comprised by 2 or more types.

The external light shielding part includes an external light shielding film having a wedge shape or a trapezoidal shape having a bottom surface exposed to the outside of the substrate and an inclined surface extending from the bottom surface.

A filter for a display device according to an aspect of the present invention includes a filter base and an external light shielding film. The external light shielding film is formed with an external light shielding pattern on one surface of a transparent resin substrate, and the external light shielding pattern includes a plurality of external light shielding parts. The external light shielding portion is characterized in that the shape of the vertical cross-section is two or more.

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

1 is a cross-sectional view showing a filter for a display device according to an embodiment of the present invention.

Referring to FIG. 1, the PDP filter 100 includes a filter base 110 and an external light shielding film 130 including functional layers having various shielding functions on the transparent substrate 112.

Here, the filter base 110 is formed by stacking the transparent substrate 112, the electromagnetic shielding film 114, or the antireflection film 116 in any order. Here, the transparent substrate 112 is generally manufactured using a transparent plastic material such as glass or acrylic. However, the transparent substrate 112 may be excluded according to the specification of the filter base 110.

In one embodiment of the present invention, examples of the transparent substrate 112 may include an inorganic compound molding such as glass or quartz and a transparent organic polymer molding. Acrylic or polycarbonate is generally used as the transparent substrate 112 made of an organic polymer molding, but the present invention is not limited to these embodiments. The transparent substrate 112 preferably has high transparency and heat resistance, and a polymer molded product and a laminate of the polymer molded product may be used as the transparent substrate 112. As for the transparency of the transparent substrate 112, it is advantageous that the visible light transmittance is 80% or more, and in terms of heat resistance, the glass transition temperature is preferably 50 ° C or more. The polymer molded article may be transparent in the visible wavelength range, and polyethylene terephthalate (PET) is preferable in terms of cost, heat resistance, and transparency, but is not limited thereto.

The anti-reflection film prevents external light incident from the viewer's direction from being reflected back to the outside, thereby improving the contrast ratio of the display. The anti-reflection film 116 according to the embodiment of the present invention is formed on the other surface of the transparent substrate 112, but the present invention is not limited to this stacking order. Preferably, as shown in Figure 1, the anti-reflection film 116 is formed effectively on the side to be the viewer side when the PDP filter 100 is mounted to the PDP device, that is, the opposite side to the panel assembly side to be.

The electromagnetic shielding film serves to block electromagnetic waves generated from the panel assembly. In order to shield the electromagnetic waves, it is necessary to cover the display surface with a highly conductive object. As the electromagnetic wave shielding film 114 for shielding electromagnetic waves according to an embodiment of the present invention, a multilayer transparent conductive film obtained by laminating a conductive mesh film or a metal thin film and a high refractive index transparent thin film may be used. As the conductive mesh film, generally, a metal mesh ground or a metal coating on a mesh of synthetic resin or metal fiber can be used. As a material of the metal which comprises a conductive mesh film, if the metal which is excellent in electroconductivity and workability, such as copper, chromium, nickel, silver, molybdenum, aluminum, can be used, for example.

In addition, the multilayer transparent conductive film may be a high refractive transparent thin film represented by indium tin oxide (ITO) to shield the electromagnetic waves. Examples of the multilayer transparent conductive film include a multilayer thin film in which metal thin films such as gold, silver, copper, platinum, and palladium are alternately stacked with high refractive index transparent thin films such as indium oxide, ditin oxide, and zinc oxide.

Although not shown, the filter base 110 according to an embodiment of the present invention may separately include a near infrared shielding layer. The near-infrared shielding layer serves to shield strong near-infrared rays generated from the panel assembly causing malfunction of electronic devices such as wireless telephones and remote controls.

In the exemplary embodiment of the present invention, when the electromagnetic shielding film 114 uses a multilayer transparent conductive film in which a metal thin film and a high refractive index transparent thin film are laminated, the multilayer transparent conductive film shields near infrared rays. Therefore, in this case, two functions of shielding near infrared rays and electromagnetic waves may be performed using only the electromagnetic shielding film 114 without separately forming the near infrared shielding layer. In this case, of course, the near-infrared shielding layer may be formed separately.

Hereinafter, in an embodiment of the present invention, the films corresponding to the electromagnetic shielding function and the anti-reflection function are separately described as separate ones, but the present invention is not limited thereto. That is, the filter base 110 according to an embodiment of the present invention may be composed of one or more layers, and each film may have an electromagnetic shielding function, an antireflection function, or a combination thereof. In addition, the filter base 110 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 130 is disposed on one surface of the filter base 110, that is, the opposite surface of the anti-reflection film 116 based on the transparent substrate 112. The external light shielding film 130 is disposed on the side of the panel assembly side of the filter base 110, that is, the side opposite to the viewer side when the PDP filter 100 is mounted to the PDP device, but the present invention is not limited thereto. The external light shielding film 130 may be disposed on the other surface of the filter base 110.

The external light shielding film 130 includes an external light shielding pattern 134 for blocking external light flowing into the panel assembly from the outside. In the present embodiment, the external light shielding pattern 134 is formed on one surface of the external light shielding film 130, but is not limited thereto and may be formed on both surfaces. In addition, in the present exemplary embodiment, the external light shielding pattern 134 may be formed of a plurality of black stripes that are spaced apart from each other at regular intervals, but the external light shielding pattern 134 may have various shapes.

Here, the external light shielding film 130 may be formed directly on the filter base 110, but after forming the external light shielding film 130 on the support 150 as shown in FIG. 1, the filter base 110 and the filter base 110 may be formed. Can be combined. The supporter 150 supports the external light shielding film 130.

In one embodiment of the present invention, the support 150 is preferably a transparent resin film having ultraviolet transmittance. Of course, as the support 150, a film having an inherent function of the filter, for example, an electromagnetic wave shielding film 114, an antireflection film 116, or a color correction layer 170 may be used. The color correction layer functions to correct a specific color of the incident light emitted from the panel assembly, and is disposed on one surface of the external light shielding film, but may be alternatively included in the filter base.

In one embodiment of the present invention, the substrate 132 of the external light shielding film is formed of an ultraviolet curable resin, the external light shielding pattern 134 is a roll molding method, a heat press method using a thermoplastic resin, or an external light shielding The shape opposite to the pattern 134 may be formed by an injection molding method for filling and molding a thermoplastic or thermosetting resin in the transferred external light shielding film 130. In addition, when the ultraviolet curable resin constituting the external light shielding film 130 has an antireflection function, an electromagnetic wave shielding function, a color control function, or a combination thereof, the external light shielding film 130 may additionally perform these functions. It may be.

The external light shielding film 130 absorbs external light to prevent external light from entering the panel assembly and totally reflects incident light emitted from the panel assembly toward the viewer. Thus, a high transmittance to visible light and a high contrast ratio can be obtained.

Hereinafter, the external light shielding film will be described in more detail.

Figure 2 is a perspective view showing an external light shielding film for a display device according to an embodiment of the present invention, Figure 3 shows an embodiment to which the present invention is applied when there is an indoor lighting device, the external light shielding of Figure 2 It conceptually illustrates the appearance of the external environmental light emitted from the illumination device with respect to the vertical section cut along the I-I 'line.

2 and 3, the external light shielding film 200 is formed on a substrate 220 made of a transparent resin material and one surface of the substrate, and includes an external light shielding pattern having a plurality of external light shielding parts 240. do. The external light shielding part 240 is arranged parallel to one surface of the substrate, and has a trapezoidal shape having a bottom surface exposed to the outside of the substrate and an inclined surface extending from the bottom surface, and when viewed in plan view, the external light shielding film It has a stripe shape parallel to the first long side 252 and the second long side 254 of (200). The present invention is not limited thereto, and the external light shielding part 240 may have a wedge shape or a general quadrangular shape, and the like, and the external light shielding pattern may have various shapes other than a stripe shape. The external light shielding film 200 forms an intaglio pattern having a predetermined shape on one surface of the substrate 220 made of a transparent resin material, and then includes a light absorber including a resin containing a light absorbing material in the intaglio pattern. It is prepared by the step of filling and curing the resin component. At this time, as the concentration of the light absorbing material to be filled increases, the light absorption efficiency increases. However, as the concentration of the light absorbing material contained in the resin increases, the viscosity of the light absorber increases, so that the filling process has to be repeated several times. Therefore, in an embodiment of the present invention, by changing the cross-sectional shape of the external light shielding portion 240 constituting the external light shielding pattern unlike in the prior art, it is intended to propose a method that can increase the contrast contrast ratio.

Hereinafter, the cross-sectional shape of the external light shielding part 240 will be described in detail.

In the present exemplary embodiment, the external light shielding pattern has a stripe shape parallel to the first long side 252 and the second long side 254 of the substrate 220, and includes a plurality of external light shields 240 spaced by a predetermined interval. Consists of. The external light shielding part 240 includes a bottom surface exposed to one surface of the external light shielding film 200 and an inclined surface extending from the bottom surface. In the present invention, the magnitude of the inclination angle formed by the normal between the inclined surface and the bottom surface, that is, the inclination of the inclined surface is not constant.

In general, the PDP device is located on the wall in the living room or room indoors, the indoor lighting device is located in the center of the ceiling of the living room or room. Light emitted from the lighting device has a predetermined angle of incidence and enters the panel of the PDP device. In the present embodiment, when viewed from the viewer side, the long side of the upper portion near the indoor lighting device 300 in the external light shielding film 200 is the first long side 252, and the long side of the opposite lower portion is the second long side 254. )to be. In addition, in the present embodiment, the shape of the vertical cross section of the external light shielding part 240 is trapezoidal, and the bottom surface of the trapezoid exposed to the outside of the substrate 220 is directed toward the viewer. An inclined surface extending from the bottom surface of the external light shielding part 240 and a normal line of the bottom surface form a predetermined taper angle (hereinafter, referred to as θ). The size of the inclination angle may range from 0 ° to 80 °. The inclined surface facing the first long side 252 in the external light shielding part 240 is the first inclined surface 242 and the inclined surface facing the second long side 254 is the second inclined surface 244. The inclination angle formed by the first slope 242 and the normal of the bottom surface is the first inclination angle θ ₁ , and the inclination angle formed by the second slope 244 and the normal of the bottom surface is the second inclination angle θ ₂ . When the inclination angle is defined as an angle in a counterclockwise direction from the normal to the inclined surface of the bottom surface, the second inclination angle of the outer light shielding portion closest to the first long side among the outer light shielding portions may have a negative value. Even in this case, the size of the second inclination angle may range from 0 ° to 80 °. In addition, the angle which the normal line of the bottom surface of an exterior light shielding part makes with the external light which injected from the indoor lighting device is an incident angle (hereinafter, referred to as (delta)).

The magnitudes of the first inclination angle θ ₁ and the second inclination angle θ _{2 of} each external light shielding unit 240 may not be constant. In addition, the first inclination angle θ ₁ and the second inclination angle θ ₂ of at least one of the plurality of external light shielding parts 240 may be different from each other. That is, the first inclination angle θ ₁ and the second inclination angle θ ₂ of the first inclined surface 242 and the second inclined surface 244 of the specific external light shield 240 are different from each other. Can be. Therefore, in the cross-sectional shape of the external light shielding portion, both inclined surfaces may be asymmetrical rather than symmetrical. In the present exemplary embodiment, the cross-sectional shape of the external light shielding parts except for the external light shielding part closest to the first long side 252 among the five external light shielding parts is asymmetric. The cross-sectional shape of the external light shielding pattern is not limited to the above embodiment, and the sizes of the first inclination angle θ ₁ and the second inclination angle θ ₂ may have various distributions.

The first inclination angle θ ₁ of at least one of the plurality of external light shields 240 may be different from the first inclination angle θ ₁ of the remaining external light shields except for the external light shield. Similarly, the second inclination angle θ ₂ of at least one external light shielding part may be different from the second inclination angle θ ₂ of the remaining external light shielding parts except for the external light shielding part. That is, the size of the first inclination angle θ ₁ opposite to the first long side 252 of the substrate may have a different value for each of the external light shielding portions, and the external light shielding portions having the same size of the first inclination angle θ ₁ . There may be several. Similarly, the size of the second inclination angle θ ₂ facing the second long side 254 of the substrate may also have different values for each of the external light shielding portions, and the external light shielding portions having the same size of the second inclination angle θ ₂ . There may be several. The magnitude of the first inclination angle θ ₁ and the second inclination angle θ ₂ may be determined purposely according to a specific embodiment.

In the present embodiment, the first inclination angle θ ₁ and the second inclination angle θ ₂ increase as the position of the external light shielding part moves away from the first long side 252 of the substrate. That is, the cross section of the external light shielding portion is inclined in the direction toward the second long side 252 from the top to the bottom of the display panel. This is to increase the external light absorption efficiency in consideration of the incident angle δ increasing from the top of the panel toward the bottom of the panel when the external light incident from the indoor lighting device 300 enters the display screen. As the incident angle δ of the external light increases, when the size of the first inclination angle θ ₁ and the second inclination angle θ ₂ increases and the shape of the cross section is inclined, the external light shielding part is inclined with respect to the direction of the incident light. The effect is to increase the depth substantially. The external light absorption efficiency increases as the concentration of the light absorber filled in the external light shield increases and the depth of the external light shield increases. However, when the concentration of the light absorber is increased or the depth of the external light shield is increased, the filling of the light absorber is incomplete, so that the light absorbing efficiency can be increased even if the concentration of the light absorber and the depth of the external light shield are constant. To provide a cross-sectional shape of the external light shielding pattern for.

In the present embodiment, the magnitude of the first inclination angle θ ₁ has a value equal to or greater than that of the second inclination angle θ ₂ , and thus, the magnitude of the first inclination angle θ ₁ and the second inclination angle θ ₂ . If the size of is different, the slope of both sides shows the trapezoidal cross-sectional shape. Compared to the case where all the external light shields have the same shape, when the external light shield includes the asymmetrical and various vertical cross-sectional shapes, the angle of reflection of the light incident from the panel is increased, so that the viewing angle in the vertical direction with respect to the viewer can be enlarged. have. In addition, the light absorption efficiency may be increased without increasing the depth of the external light shielding portion or increasing the concentration of the filled light absorber. That is, since the light absorption efficiency is increased with respect to the area of the external light shielding portion, the amount of light absorber required to exhibit the same light absorption efficiency is reduced. Therefore, the transmittance of light emitted from the panel can be increased, thereby increasing the brightness of the display.

In applying the present invention, the cross-sectional shape of the external light shielding pattern optimized for external light absorption efficiency may be configured in consideration of the general height of the indoor lighting device, the size of the display device, and the location where the display device is generally installed. .

As described above, according to the present invention, when the external environment light is incident on the display, in consideration of the angle of incidence depending on the incidence position on the display screen, the shape of the vertical cross section of the external light shielding portion is formed by two or more types, thereby absorbing the external environment light The efficiency can be increased to increase the contrast ratio.

In addition, the light emitted from the panel and incident on the film has a larger reflection angle than the case where the cross-sectional shape is constant due to the cross-sectional shape of the external light shielding part of the present invention. That is, it serves to enlarge the viewing angle in the vertical direction with respect to the viewer.

As described above, although the present invention has been described with reference to limited embodiments and drawings, 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.

Claims (12)

      Base material of transparent resin material; And An external light shielding film formed on one surface of the substrate, the external light shielding film including an external light shielding pattern having a plurality of external light shielding parts, wherein the cross-sectional shape of the external light shielding part is at least two or more. The method of claim 1, The external light shielding portion is arranged in parallel with one surface of the substrate, and a wedge shaped external light including a bottom surface exposed to the outside of the substrate and an inclined surface extending from the bottom surface and having a predetermined inclination angle with respect to the normal of the bottom surface. An external light shielding film, characterized in that the shield. The method of claim 2, The external light shielding portion is arranged in parallel to one long side of the base material, the external light shielding film. The method of claim 3, The external light shielding portions may include a first inclined surface facing one long side of the substrate and a second inclined surface facing the other long side of the substrate, wherein the inclined angle is a first inclined angle formed by the first inclined surface and the second inclined surface. And a second inclination angle formed by the external light shielding film. The method of claim 4, wherein The first and second inclination angles of at least one of the external light shielding parts of the external light shielding part are different from each other. The method of claim 4, wherein The first inclination angle of at least one of the external light shielding part is different from the first inclination angle of the remaining external light shielding parts except for the external light shielding part. The method of claim 4, wherein The second inclination angle of at least one of the external light shielding portions is different from the second inclination angles of the remaining external light shielding portions except for the external light shielding portion. The method of claim 2, The angle of inclination of the external light shielding film, characterized in that 0 ° to 80 °. The method of claim 4, wherein The first inclination angle and the second inclination angle of the external light shielding film, characterized in that increases or decreases away from one long side of the substrate. The method of claim 9, The size of the first inclination angle is the same or larger than the size of the second inclination angle, the external light shielding film. Filter base; And Is formed in one region of the filter base, i) a substrate made of a transparent resin material; And ii) having an external light shielding film formed on one surface of the substrate and including an external light shielding pattern composed of a plurality of external light shielding parts; In the filter for display device, The vertical cross-sectional shape of the exterior light shielding unit is at least two or more filters. The method of claim 11, The filter base, Transparent Board, An electromagnetic shielding film disposed on one surface of the transparent substrate and blocking electromagnetic waves generated from the panel assembly; And And an anti-reflection film disposed on one surface of the transparent substrate to prevent reflection of external light.

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