KR20080019990A - Functional film and display device using thereof - Google Patents

Abstract

A functional film and an image display device using the same are provided to be used in the mobile display device weak to the reflection of the external light, by decreasing the reflection generated by the external light and making the withdrawn light reach to a user without loss. A functional film is composed of a light transmitting unit having light transmissive films(612,613,614,615); a light reflecting unit installed at the outer side of the light transmitting unit to reflect the light passing through the light transmitting unit; and an external light absorbing unit installed at the outer side of the light reflecting unit to absorb the external light. An area of a light withdrawing surface of the light transmissive film is smaller than an area of an incident surface. Refractive indexes of the incident surface and the light withdrawing surface are different from each other.

Description

Functional Film and Display Device Using Thereof

1 is a cross-sectional view of the anti-reflection film structure corresponding to the prior art.

2 is a cross-sectional view for explaining the problem of the anti-reflection film corresponding to the prior art.

3 is a cross-sectional view of a functional film according to an embodiment of the present invention.

4 is a flowchart illustrating a method of manufacturing a functional film according to an embodiment of the present invention.

5 is a process flowchart illustrating another method of manufacturing a functional film according to an embodiment of the present invention.

6 is a process flowchart illustrating another method of manufacturing a functional film according to an embodiment of the present invention.

7 is an image display device having a functional film according to an embodiment of the present invention.

8 is a video display device having a functional film according to another embodiment of the present invention.

9 is a cross-sectional view of a functional film according to another embodiment of the present invention.

10 is a cross-sectional view of a functional film according to another embodiment of the present invention.

Republic of Korea Patent Publication No. 10-2004-0094239

The present invention relates to a functional film for light, and more particularly to an antireflection film or an asymmetric light transmitting film.

Anti-reflection film is a technology widely used in solar cells and video display devices. In the case of a video display device, a user cannot see a display image by the reflected light from an external light display device instead of the image light to be displayed. Used for.

In addition, in order to prevent the inside of the vehicle from being easily seen from the outside, coating is applied to the vehicle glass, which blocks the external visible light, thereby making it difficult for the driver to identify information coming from the outside at night, which may cause an accident.

In the conventional general anti-reflection film, a plurality of layers having different refractive indices may be formed, but in this case, there is a problem that the effect of preventing external light reflection is weak.

In addition, in the case of the technology mentioned in the Republic of Korea Patent Publication No. 10-2004-0094239, it is possible to increase the anti-reflection of the external light, but also has a problem that the light of the image to be displayed is also blocked, the details will be described as follows do.

The light emitted from the display panels 110 to 140 is sent to the user's field of view by the reflective film 151 on the inner side of the trapezoidal shape, and the external light 161 enters the opening 157 of the trapezoidal shape of the external light blocking structure. The remaining light is blocked by the light absorption film 153 located on the outer side of the trapezoidal shape, so that the area occupied by the opening in the total planar area is 30%. Patent Publication No. 10-2004-0094239 discloses 70% of the external light. It is explained that the light emitted from the display panel theoretically sends 100% to the user.

However, referring to FIG. 2, according to the position and direction of the light emitted from the display panel, a considerable amount of light does not come out to the user through the opening 240 and has a problem of returning back to the display panel. For example, even if it is assumed that only the light 221 diverging from the center of the relatively trapezoidal shape enters the user's field of view through the opening 240, even if it is assumed to be diffused only vertically to the panel surface without considering the radial propagation direction, which is a property of light. In the case of light 220 emitted from an outer portion of the trapezoidal shape, as the number of reflections by the reflective film on the inner side of the trapezoidal shape increases, the reflection angle increases as a result of the increase in the visibility of the user through the opening 240. It does not reach and a phenomenon which returns to the display panel side occurs. Considering the radioactive properties of the light, light having a radiation angle above a certain angle with the vertical plane of the display panel among the light emitted from the center of the relatively trapezoidal shape does not exit through the opening and returns.

Therefore, in the related art, since a large part of the light of the display panel does not reach the user, there is a problem in that the effect of the anti-reflection film cannot be obtained.

An object of the present invention is to solve the problems of the prior art as described above, and to block the majority of the external light while the functional film for the light to be extracted without a large loss of the internal light, and a manufacturing method thereof and an image display device using the same To provide.

In another application, the functional membrane of the present invention is applied to a vehicle so that light inside the vehicle does not go out, and light outside the vehicle is provided to the driver, thereby preventing the user from seeing the inside of the vehicle from outside. To provide an asymmetric light transmitting membrane.

According to the present invention for achieving the above object, the area of the light extraction surface from which the light is taken out is smaller than the incident surface to which light is incident, and the light transmitting part configured to have a different refractive index on the incident surface side and a refractive index on the extraction surface side. ; A light reflection unit provided outside the light transmission unit to reflect the light passing through the light transmission unit; And an external light absorbing part provided outside the light reflecting part to absorb external light.

Moreover, this invention is a functional film | membrane in which the said light transmitting part has the refractive index of the said incident surface side smaller than the refractive index of the said extraction surface side.

In addition, the present invention is a functional film, characterized in that the light transmitting portion is composed of at least two different films having different refractive indices.

In addition, the present invention is a functional film, characterized in that the light transmitting portion is composed of a film formed by forming a concentration gradient of at least two different materials having different refractive indices.

In addition, the present invention provides a light transmitting unit comprising a first film having a first refractive index and a second film having a second refractive index positioned on the first film; A light reflection unit provided outside the light transmission unit; And an external light absorbing part provided outside the light reflecting part.

The present invention is also a functional film, wherein the first refractive index is smaller than the second refractive index.

The present invention also provides a method of forming a film including: forming a first film having a first refractive index; Forming a second film having a second refractive index on top of the first film; Applying a photosensitive agent over the second film and forming a photosensitive pattern in an arbitrary shape; Etching the first layer and the second layer using the photosensitive pattern as a mask; Forming a light reflection layer on the photosensitive pattern, the first film, and the second film; Forming a light absorption layer on the light reflection layer; And removing the photosensitive pattern.

In addition, the present invention includes forming a film so that a concentration gradient is formed between a first material having a first refractive index and a second material having a second refractive index; Applying a photosensitive agent on top of the film and forming a photosensitive pattern in an arbitrary shape; Etching the film using the photosensitive pattern as a mask; Forming a light reflection layer on the photosensitive pattern and the film; Forming a light absorption layer on the light reflection layer; And removing the photosensitive pattern.

In addition, the present invention relates to an image display device including a functional film manufactured by the anti-reflection film and a manufacturing method thereof.

Hereinafter, the functional film for the description of the present invention will be described as an application corresponding to the anti-reflection film for ease of explanation, and the use as an asymmetric light transmitting film applied to a vehicle is omitted so since it corresponds to a degree easily applicable to those skilled in the art. do.

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

In the anti-reflection film according to the present invention, one of the anti-reflection films having a plurality of trapezoidal cross-sectional shapes shown in FIGS. 4 to 8 is shown in FIG. 3 and applied to an image display device. However, the anti-reflection film of the present invention is not limited to the image display device.

Among the lights 420 and 421 extracted from the image display device, the light paths of the light 421 perpendicular to the incident surface and the light 421 not perpendicular to each other may be different from each other, but the refractive index of the light transmitting part 410 on the incident surface side may be different from each other. The refractive index n5 of the light transmitting portion 410 on the extraction surface side is relatively larger than n1), and the light 420 and 421 is increased as the angle between the reflective layer 411 located at the outer portion of the light transmitting portion 410 and the incident surface is larger. The possibility of taking out through the opening 440 becomes high. When the light incident through the incident surface is reflected on the inclined reflective layer 411, the incident angle and the reflected angle are the same for the reflective layer 411, but when the reflected light is based on the incident surface, the inclination angle of the reflective layer 411 is used. When the light is incident on the film having a high refractive index, the light is refracted toward the opening 440, and the light refracted by the light is opposite to the reflected reflective layer 411. When the reflective layer 411 is located, it is lower than the angle indicated by the problem in FIG. 2 referred to in the prior art, so that the light is continuously refracted toward the opening 440 while meeting the high refractive index layer, and eventually the light is opened. It will be extracted through. In addition, a light absorbing layer 412 that absorbs external light exists outside the reflective layer 411 to block light that is intended to enter the image display device in a direction opposite to light emitted from the image display device in an area except the opening 440. Done. Therefore, the blocking rate of external light is equal to the area of the entire anti-reflection film relative to the area of the opening, and the light emitted from the image display device is almost lost to the user according to the inclination angle of the reflective layer 411 and the refractive index of the film forming the light transmitting part. Will be reached.

4 is an illustration for explaining a method of manufacturing the anti-reflection film of the present invention.

From the light-transmitting film 611 having a low refractive index, the light-transmitting films 612, 613, 614, and 615 having a high refractive index are sequentially formed (610), a photosensitive film is formed thereon, and then a photosensitive pattern 621 corresponding to the opening is formed (620). By using the photosensitive pattern 621 as a mask, an etch process or a laser is used to form a film formed of the light transmissive layers in a triangular or trapezoidal form (630), and in the state where the photosensitive pattern 621 is present, the metal, in particular aluminum or its A film including the compound is formed 641 to form a reflective layer, and a light absorbing layer capable of absorbing light is formed thereon. The material of the light absorption layer may be in any form such as organic carbon, inorganic carbon and chromium oxide.

Finally, the photosensitive pattern 621 is peeled off to form a trapezoidal antireflection film having an opening 651.

Vapor phase deposition or spin coating and inkjet coating may be used as the method for forming the light transmitting films 611, 612, 613, and 615. The method may vary depending on the selection of the material of the light transmissive film, and may be selectively used depending on the etching solution used in the etching process for forming the trapezoidal shape.

In addition, it is preferable that the difference in refractive index between the film having the smallest refractive index and the film having the largest refractive index among the light transmissive films is as large as possible.

FIG. 5 illustrates a process for reducing irregularities with the preferred further process of FIG. 4.

Since the concave-convex portions formed between the openings after the process described with reference to FIG. 4 may degrade the durability of the film, an additional light-transmissive film 661 having an arbitrary refractive index may be further formed to improve the durability, and the light transmittance The refractive index of the film 661 may be lower than the refractive index of the light transmissive film 615 facing the opening, thereby diffusing the light taken out through the opening.

6 illustrates another process for reducing irregularities.

In FIG. 4, after forming the reflective layer 641, the light absorbing layer is formed of an organic film instead of an inorganic film, or is formed by a coating process rather than an evaporation process, thereby forming grooves between the openings, and then forming an opening by removing a photosensitive pattern. That's how.

FIG. 7 illustrates that the anti-reflection film 911 manufactured by the method of FIG. 5 is formed on the image display device 910.

FIG. 8 illustrates that an anti-reflection film 1011 manufactured by the method of FIG. 6 is formed on the image display device 1010.

FIG. 9 illustrates another embodiment of the present invention. In FIG. 4, the etching ratio and the time may be determined in the step 630 of etching the light-transmissive film by the etching process 631 using the photosensitive pattern 621 as a mask. By adjusting the outer surface of the light transmissive film to form a round or angle it can be further improved light extraction rate.

FIG. 10 illustrates a method of improving the light extraction rate by forming materials having different refractive indices constituting the light transmissive film to have a concentration gradient. In the manufacturing method of FIG. 4, the light transmissive film is formed in step 610. It is possible to form a film having a concentration gradient by sequentially depositing by controlling deposition amounts of at least two materials having different refractive indices without sequentially forming materials having different refractive indices.

According to the cutting line AA, the material having a refractive index n2 having a larger refractive index than the refractive index n1 is formed to have a higher concentration than the material having a refractive index n1 as the opening is closer to the opening.

In particular, the method of forming the film having a concentration gradient is a process by using two materials having a large difference in mutual refractive index without applying several materials having different refractive indices used in the light-transmissive film as compared to the method of forming a multilayer film. There is an advantage in gaining efficiency.

Although not shown in the drawings, a method of combining the structure of the multilayer film and the structure of the concentration gradient is also possible.

Since the sequential deposition method for the etching conditions and the concentration gradient in the contents described in the present invention are well known techniques, detailed descriptions thereof will be omitted.

As described above, according to the functional film according to the present invention, the light emitted from the image display device can be reached to the user with little loss while reducing the reflection by external light, thereby being used in a mobile display device that is vulnerable to external light reflection. This is suitable, and also can be produced in the form of a film, so that it may be possible to remove the user's convenience. In addition, when the functional film according to the present invention is applied to a vehicle, it can be used as an effective vehicle coating film by making a difference between light coming in from the inside and light going out from the inside.

Claims (10)

A light transmissive portion formed with a smaller area of the extraction surface from which the light is incident than an incident surface from which light is incident, and including a light transmissive film having a different refractive index on the incident surface side and a refractive index on the extraction surface side; A light reflection unit provided outside the light transmission unit to reflect the light passing through the light transmission unit; And A functional film provided on the outside of the light reflection portion, including an external light absorbing portion for absorbing external light. The functional film according to claim 1, wherein the light transmissive portion has a refractive index on the incident surface side smaller than that on the extraction surface side. The functional film of claim 1, wherein the light transmitting part is composed of at least two different films having different refractive indices. The functional film of claim 1, wherein the light transmitting part comprises a film formed by forming a concentration gradient of at least two different materials having different refractive indices. A light transmitting portion comprising a first film having a first refractive index and a second film having a second refractive index positioned on top of the first film; A light reflection unit provided outside the light transmission unit; And Functional film including an external light absorbing portion provided on the outside of the light reflecting portion. 6. The functional film of claim 5, wherein the first refractive index is smaller than the second refractive index. The video display device of claim 1, further comprising the functional film. Forming a first film having a first refractive index; Forming a second film having a second refractive index on top of the first film; Applying a photosensitive agent over the second film and forming a photosensitive pattern in an arbitrary shape; Etching the first layer and the second layer using the photosensitive pattern as a mask; Forming a light reflection layer on the photosensitive pattern, the first film, and the second film; Forming a light absorption layer on the light reflection layer; And And removing the photosensitive pattern. Forming a film of a first material having a first refractive index and a second material having a second refractive index such that a concentration gradient is formed; Applying a photosensitive agent on top of the film and forming a photosensitive pattern in an arbitrary shape; Etching the film using the photosensitive pattern as a mask; Forming a light reflection layer on the photosensitive pattern and the film; Forming a light absorption layer on the light reflection layer; And And removing the photosensitive pattern. 10. The method of claim 8, further comprising forming a film having a refractive index lower than the second refractive index after removing the photosensitive pattern.

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