JP2005321448A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device of which the transparency of a window part is improved and which is suitable for mass-production. <P>SOLUTION: In the liquid crystal display device having a liquid crystal panel and a backlight, the liquid crystal panel has the window part where a display other than the liquid crystal display appears on the display region, the backlight is constructed by having a light guide body and a light source on the side face of the light guide body, and the light guide body is constructed by having an AR (anti reflection) layer at least on a place corresponding to the window part of the liquid crystal panel and disposing a reflection plate on a place other than the place corresponding to the window part on the surface opposite to the side where the liquid crystal panel is disposed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device having a display area, and more particularly to a liquid crystal display device in which a non-display area that does not perform liquid crystal display is formed in a part of the display area.

  The liquid crystal display device includes each transparent substrate opposed to the liquid crystal as an envelope, and includes a large number of pixels in the liquid crystal spreading direction. In each of these pixels, a pixel electrode and a counter electrode to which a voltage corresponding to a video signal is applied are formed on the surface of each transparent substrate on the liquid crystal side, and the liquid crystal of the pixel is optically modulated by an electric field generated by these electrodes. It has become so. A polarizing plate is disposed on the surface of each transparent substrate opposite to the liquid crystal so that the light modulation amount of the liquid crystal can be visualized as the light transmission amount.

  Since such a liquid crystal display device can be driven with low power consumption, it has been used for various purposes in recent years. For example, a window part is formed in the center part of the display panel, and an observer can see a member placed on the back surface of the liquid crystal display panel through this window part.

  FIG. 7 is a diagram showing a liquid crystal display device in which a window portion is formed at the center of the display panel. In FIG. 7, 11 is a lower transparent substrate, 12 is an upper transparent substrate, and a scanning line driving circuit 13 and a signal line driving circuit 14 are arranged on the lower transparent substrate. The scanning lines 15 are arranged, and the signal line driving circuit 14 is configured by arranging a plurality of signal lines 16 so as to intersect the plurality of scanning lines 15. FIG. 7 shows that the window 17 is formed at the center of the display area formed by intersecting the scanning lines 15 and the signal lines 16.

  FIG. 8 is a diagram showing a cross-sectional configuration taken along the line A-A ′ of FIG. 7. First, a pair of transparent substrates (for example, glass substrates) 11 and 12 sandwich a liquid crystal 23, and polarizing plates 21 and 22 are arranged on each of the pair of transparent substrates to constitute a liquid crystal panel. An optical sheet 24 (a diffusion sheet, a prism sheet, or the like) disposed corresponding to a portion other than the window portion 17 of the liquid crystal panel is disposed below the liquid crystal panel. Further, a light guide 25 having a light source 31 and a reflector 28 disposed on the side is disposed below the optical sheet 24. Below the light guide 25, a reflector 27 is disposed at a location other than the location corresponding to the window portion 17, and a member 30 is disposed at a location corresponding to the window portion 17.

  FIG. 9 is a perspective view showing the configuration of the light guide plate 25. A reflection plate 27 is disposed below the light guide plate 25, and a dot pattern 26 is applied by dot printing, for example, corresponding to the position where the reflection plate 27 is disposed. The dot pattern 26 is arranged to guide the light guided to the light guide plate 25 from the light source 31 and the reflection plate 28 to the upper side of the light guide 25 (the liquid crystal panel side). The reflecting plate 27 is arranged to guide light traveling downward from the light guide plate 25 upward.

  FIG. 10 is a diagram showing in detail the relationship between the dot pattern 26 and the reflection plate 27 arranged on the lower surface of the light guide plate 25. As shown in FIG. 10, a dot pattern 26 is disposed on the lower surface of the light guide 25, and a reflecting plate 27 is disposed so as to cover the dot pattern 26.

As a technique for performing an AR process (low reflection process) on a light guide to be described later, Patent Document 1 below, in which an AR process is performed on a liquid crystal panel side of a front light type light guide, can be cited.
JP 2003-161940 A

  In a liquid crystal display device having a window portion, it is considered necessary to display the members well, but the conventional technology does not give any consideration to this point. Here, in order to display the members satisfactorily, means for forming the light guide by cutting through a portion of the light guide corresponding to the window of the liquid crystal panel can be considered, but this means corresponds to the window. It is possible to increase the transparency of the location, but considering the cost of piercing such as this, mass productivity is impaired and it is considered that it is not practical at present.

  An object of the present invention is to provide a liquid crystal display device suitable for mass production by increasing the transparency of a window portion.

  According to one embodiment of the present application, in the liquid crystal display device having a liquid crystal panel and a backlight, the liquid crystal panel has a window portion that performs display other than liquid crystal display in a display area, and the backlight includes: The light guide has a light source on the side surface of the light guide, and the light guide has an anti-reflection layer (both antireflection layer or low reflection layer) at least at a position corresponding to the window of the liquid crystal panel. (Hereinafter abbreviated as AR layer), and on the surface opposite to where the liquid crystal panel is disposed, a reflector is disposed at a location other than the location corresponding to the window portion. Is.

  In addition, this AR layer performs reflection prevention using an optical interference action, and forms a layer with a material whose refractive index is lower than a light guide. At this time, the thickness of the AR layer is set to ¼ of the wavelength of light in the AR layer.

  According to another embodiment of the present application, in the liquid crystal display device having a liquid crystal panel and a backlight, the liquid crystal panel has a window portion for performing display other than liquid crystal display in a display area, and the back The light is configured to include a light guide and a light source on a side surface of the light guide, and the light guide includes an upper AR layer on a surface on which the liquid crystal panel is disposed, and the liquid crystal panel On the surface opposite to where the is disposed, a reflector is disposed at a location other than the location corresponding to the window portion.

  And according to still another embodiment of the present application, in the liquid crystal display device having a liquid crystal panel and a backlight, the liquid crystal panel has a window portion for performing display other than liquid crystal display in a display region, The backlight includes a light guide and a light source on a side surface of the light guide, and the light guide corresponds to the window on the side opposite to the liquid crystal panel. A reflective plate is disposed at a location other than the location, a dot pattern is disposed between the reflective plate, and a lower AR layer is disposed at a location corresponding to the window portion of the light guide. In the place where the reflector is disposed, the lower AR layer is disposed between the reflector and the reflector. In addition, this dot pattern is arranged to guide the light guided to the light guide plate from the light source and the reflection plate, as described above, above the light guide (on the liquid crystal panel side). It shows what has a function. For example, in addition to the dot pattern, a texture pattern opposite to the dot pattern is also conceivable.

  According to the present invention, it is possible to provide a liquid crystal display device which is low in cost and can ensure transparency of the window portion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of the examples. FIG. 1 is a diagram showing the features of the present invention showing the portions corresponding to the conventional configuration of FIG. The configuration other than this characteristic point is the same as the configuration in FIG. 6 and FIG. 8 in the conventional configuration. As shown in FIG. 1, the present invention is characterized in that the AR layer 1 (low reflection layer) is provided above the light guide 25 (on the liquid crystal panel side), and further corresponds to the window 17 below the light guide 25. In addition, the AR layer 2 is also included.

  In this way, by arranging the AR layer at locations corresponding to the upper and lower window portions 17 of the light guide 25, the visibility is improved at locations corresponding to the window portions 17 of the light guide 25, and the window portions. The member 30 arranged under the member 17 can be visually recognized well. This will be described in detail below.

  First, when the light guide is made of, for example, an acrylic resin, the refractive index of the acrylic resin is about 1.5, but there are air layers with a refractive index of about 1.0 above and below the acrylic resin, so that the refractive index difference Exists. Due to this difference in refractive index, part of the light incident on the acrylic resin is reflected on the surface of the acrylic resin, and the reflected light makes it difficult to see the inside of the acrylic resin and the other side. Therefore, by placing an AR layer (low reflection layer) on the surface of the acrylic resin, the reflected wave of the AR layer and the reflected wave of the surface of the acrylic resin interfere with each other, and cancel each other to reduce the reflectivity. It improves internal transparency. Here, the light guide has been described by taking an acrylic resin as an example, but other materials can be applied as long as the refractive index is higher than that of the air layer and satisfy the above-described principle of light refraction. . For example, in addition to the acrylic resin, cycloolefin, PET (polyethylene terephthalate), PC (polycarbonate) and the like are applicable as the light guide of the present invention.

  1 shows a configuration in which the AR layer 1 and the AR layer 2 are disposed on the upper surface and the lower surface corresponding to the window portion 17 of the light guide 25, respectively, but the AR layer is provided only on one surface of the upper surface or the lower surface. Even in the arrangement, the visibility of the member 30 is improved as compared with a liquid crystal display device having an arrangement in which the AR layers are not arranged on both sides.

  Further, in the configuration of FIG. 1, the visibility of the member 30 can be further improved by removing the polarizing plate at a location corresponding to the window portion of the polarizing plate of the liquid crystal panel. In this case, if the polarizing plate is removed from each of the upper and lower polarizing plates of the liquid crystal panel, a further effect can be obtained.

  Next, a configuration in which productivity is further improved in the configuration of the present invention will be examined. In the configuration of FIG. 1, the configuration in which the AR layer is applied only to the portions corresponding to the window portions 17 on the upper surface and the lower surface of the light guide 25 is shown. Although the improvement of the visibility of the member 30 under the window part 17 can be achieved by arranging the AR layer 1 and the AR layer 2 only at a position corresponding to the window part 17 as shown in FIG. In consideration of mass productivity, the AR layer is disposed on the entire upper surface or the lower surface of the light guide 25 rather than the AR layer 1 and the AR layer 2 disposed only in the portion corresponding only to the window portion 17. It is considered that the configuration is suitable for mass production.

  FIG. 2 shows a configuration in which the AR layer 1 is disposed not only on the upper surface side of the light guide 25 but also on the one surface as well as in the portion corresponding to the window portion 17. Compared with the configuration of FIG. 1, this configuration is a configuration in which the AR layer 1 is not selectively disposed, but is disposed on the entire surface, thereby being excellent in productivity and mass productivity. For example. Arrangement of a desired AR layer can be realized by applying an AR coating on one surface of the light guide 25 by sticking an AR film or depositing an AR film. Note that the surface of the light guide 25 may be hard-coated before AR deposition on the light guide 25.

  Next, in consideration of further improving productivity and mass productivity, it is necessary to devise the AR layer 2 on the lower surface of the light guide 25.

  The problem in arranging the AR layer 2 on one surface of the lower surface of the light guide 25 is that the dot pattern 26 and the reflector 27 are arranged on the lower surface of the light guide 25 other than the portion corresponding to the window portion 17. In view of productivity or mass productivity, it is considered that the positional relationship among the dot pattern 26, the reflector 27, and the AR layer 2 is important.

  3 to 6 show a possible method when the AR layer 2 is applied in addition to the portion corresponding to the window portion 17 on the lower surface of the light guide 25. FIG. 3 illustrates that a composite film 32 having a dot pattern and an AR film layer is attached to the lower surface of the light guide 25 to realize a configuration in which a desired AR layer is disposed on the light guide. This composite film 32 forms an AR layer 2 by applying an AR coating on one side of a transparent substrate 33 such as PET by applying an AR film or depositing an AR film, and forming a dot pattern 26 and this dot pattern on another side. The adhesive material 34 is arranged on the top 26.

  FIG. 4 shows an AR layer 2 in which a dot pattern 26 is applied to the lower surface of the light guide 25 and an AR film is applied to the lower surface of the light guide 25 by applying an AR film or depositing an AR film. is there.

  FIG. 5 shows that the AR layer 2 is formed by applying an AR coating to the lower surface of the light guide 25 by applying an AR film or depositing an AR film, and the dot pattern 26 is applied to the AR layer 2 on the lower surface. FIG.

  In FIG. 6, for example, an AR layer 2 made of an AR film is provided with a dot pattern 26 on the lower surface of the light guide 25, and the AR layer 2 is arranged on the lower surface of the light guide 25. FIG.

  Thus, the present invention can be realized by various methods.

  3 to 6 show the configuration other than the portion corresponding to the window portion 17 on the lower surface of the light guide 25, the configuration of the portion corresponding to the window portion 17 of the light guide 25 is shown in FIG. In each configuration of FIG. 6, the dot pattern is not arranged. In addition, the reflecting plate 27 is disposed and configured on the lower side of these configurations.

  3 to 6, hard coating may be performed on the surface of the light guide 25 before AR deposition is performed on the light guide 25.

It is a figure which shows the structure which performed AR process to the light guide in this invention. It is a figure which shows the structure which performed AR process to the light guide in this invention. It is a figure which shows the structure which performs AR process on the lower surface of the light guide in this invention. It is another figure which shows the structure which performed AR process on the lower surface of the light guide in this invention. It is another figure which shows the structure which performed AR process on the lower surface of the light guide in this invention. It is another figure which shows the structure which performed AR process on the lower surface of the light guide in this invention. It is a figure which shows the liquid crystal display device which formed the window part in the center part of the display panel. It is the figure which showed the cross-sectional structure of FIG. Z1 in a conventional structure. FIG. 6 is a perspective view illustrating a configuration of a light guide plate 25. It is a figure which shows in detail the relationship between the dot printing arrange | positioned on the lower surface of the light-guide plate in a conventional structure, and arrangement | positioning of a reflecting plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Upper AR layer, 2 ... Lower AR layer, 11 ... Upper transparent substrate, 12 ... Lower transparent substrate, 13 ... Scanning line drive circuit, 14 ... Signal line drive Circuit, 15 ... Scanning line, 16 ... Signal line, 17 ... Window, 21 ... Upper polarizing plate, 22 ... Lower polarizing plate, 23 ... Liquid crystal, 24 ... Optical sheet, 25... Light guide, 26... Dot pattern, 27 .. reflector, 28. 32 ... Composite film, 33 ... Transparent substrate, 34 ... Adhesive.

Claims (20)

In a liquid crystal display device having a liquid crystal panel and a backlight,
The liquid crystal panel has a window portion for performing display other than liquid crystal display in a display area,
The backlight is configured with a light source and a light source on a side surface of the light guide,
The light guide has an anti-reflection layer at least in a portion corresponding to the window portion of the liquid crystal panel, and a portion corresponding to the window portion on a surface opposite to the liquid crystal panel is disposed. A liquid crystal display device in which reflectors are arranged at other locations. The liquid crystal display device according to claim 1.
The liquid crystal display device, wherein the anti-reflection layer is disposed on a surface of the light guide on a side where a liquid crystal panel is disposed. The liquid crystal display device according to claim 1.
The liquid crystal display device, wherein the anti-reflection layer is disposed on a surface of the light guide opposite to a side where a liquid crystal panel is disposed. The liquid crystal display device according to claim 1.
2. The liquid crystal display device according to claim 1, wherein the anti-reflection layer is disposed on both sides of the light guide on which the liquid crystal panel is disposed and on the opposite side. The liquid crystal display device according to any one of claims 1 to 4,
An optical sheet is disposed between the backlight and the liquid crystal panel. In a liquid crystal display device having a liquid crystal panel and a backlight,
The liquid crystal panel has a window portion for performing display other than liquid crystal display in a display area,
The backlight is configured with a light source and a light source on a side surface of the light guide,
The light guide has an upper anti-reflection layer on the surface on which the liquid crystal panel is disposed, and corresponds to a window on the surface opposite to the surface on which the liquid crystal panel is disposed. A liquid crystal display device in which reflectors are arranged at locations other than locations. The liquid crystal display device according to claim 6.
The light guide has a lower anti-reflection layer on the surface opposite to where the liquid crystal panel is disposed,
The liquid crystal display device, wherein the lower anti-reflection layer is disposed between the reflector and the liquid crystal panel. The liquid crystal display device according to claim 7.
A liquid crystal display device, wherein a dot pattern is disposed between the lower anti-reflection layer and the light guide. The liquid crystal display device according to claim 8.
The liquid crystal display device is characterized in that the war dot printing is applied to the light guide. The liquid crystal display device according to claim 8.
The liquid crystal display device, wherein the lower anti-reflection layer is disposed on one side of a transparent substrate, and the dot printing is performed on the other side of the transparent substrate. The liquid crystal display device according to claim 10.
An adhesive is disposed so as to cover the transparent substrate and the dot pattern, and the adhesive and the light guide are in contact with each other. The liquid crystal display device according to claim 7.
A liquid crystal display device, wherein a dot pattern is disposed between the lower anti-reflection layer and the reflector. The liquid crystal display device according to claim 12.
The liquid crystal display device, wherein the dot pattern is formed on the lower anti-reflection layer. The liquid crystal display device according to any one of claims 6 to 13,
A liquid crystal display device, wherein at least one optical sheet is disposed between the liquid crystal panel and the light guide. In a liquid crystal display device having a liquid crystal panel and a backlight,
The liquid crystal panel has a window portion for performing display other than liquid crystal display in a display area,
The backlight is configured with a light source and a light source on a side surface of the light guide,
In the light guide, on the side opposite to where the liquid crystal panel is disposed, a reflective plate is disposed at a location other than the location corresponding to the window portion, and a dot pattern is disposed between the reflective plate and the light guide. Has been
A lower anti-reflection layer is disposed at a position corresponding to the window portion of the light guide, and a lower anti-reflection layer is disposed between the light reflector and the reflector. Is a liquid crystal display device. The liquid crystal display device according to claim 15.
The liquid crystal display device, wherein the dot pattern is provided between the light guide and the lower anti-reflection layer. The liquid crystal display device according to claim 15.
The liquid crystal display device, wherein the dot pattern is provided between the lower anti-reflection layer and the reflector. The liquid crystal display device according to any one of claims 15 to 17,
A liquid crystal display device, wherein an upper anti-reflection layer is disposed at least at a position corresponding to the window on the liquid crystal panel side of the light guide. The liquid crystal display device according to claim 18.
The liquid crystal display device, wherein the upper anti-reflection layer is disposed on one surface of the light guide. The liquid crystal display device according to any one of claims 15 to 19,
A liquid crystal display device, wherein at least one optical sheet is disposed between the liquid crystal panel and the light guide.

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