JP2015191053A - liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device that enables enhancement in luminance and improvement in a luminance field viewing angle to be attained.SOLUTION: A liquid crystal display device comprises: a light source unit; a first liquid crystal panel on which a first video image based on a video image signal is displayed; a second liquid crystal panel which is arranged between the light source unit and the first liquid crystal panel and on which a second video image based on the first video image is displayed; a diffusion layer that is arranged between the first liquid crystal panel and the second liquid crystal panel; and a reflection suppressive layer that is provided at one of between the diffusion layer and the first liquid crystal panel and between the diffusion layer and the second liquid crystal panel.

Description

  The present disclosure relates to a liquid crystal display device that performs video display using a plurality of liquid crystal panels.

  In the field of liquid crystal display devices (LCDs), there are techniques for displaying images by arranging two liquid crystal display panels (liquid crystal panels) in an overlapping manner (for example, Patent Documents 1 and 2). According to this technique, it is possible to suppress light leakage from the backlight as compared with the case of one liquid crystal panel. The black luminance can be reduced and the contrast ratio can be improved.

International Publication No. 2007/08166 Pamphlet International Publication No. 2007/108183 Pamphlet

  However, when a plurality of liquid crystal panels are arranged as described above, there is a concern that the luminance and the luminance viewing angle are lowered. Realization of a liquid crystal display device capable of improving the luminance and the luminance viewing angle is desired.

  The present disclosure has been made in view of such problems, and an object thereof is to provide a liquid crystal display device capable of realizing improvement in luminance and improvement in luminance viewing angle.

  A liquid crystal display device according to the present disclosure is disposed between a light source unit, a first liquid crystal panel on which a first video based on a video signal is displayed, and between the light source unit and the first liquid crystal panel. A second liquid crystal panel on which a second image corresponding to the first image is displayed, a diffusion layer disposed between the first liquid crystal panel and the second liquid crystal panel, a diffusion layer and the first liquid crystal panel And a reflection suppressing layer provided on one of the diffusion layer and the second liquid crystal panel.

  In the liquid crystal display device according to the present disclosure, light from the light source unit is irradiated to the first liquid crystal panel and the second liquid crystal panel, and the first liquid crystal panel has the first image, and the second liquid crystal panel has the second image. Each video is displayed. By disposing a diffusion layer between the first liquid crystal panel and the second liquid crystal panel, so-called moire (moiré, interference fringes) is suppressed. Further, a reflection suppressing layer is provided between one of the diffusion layer and the first liquid crystal panel and between the diffusion layer and the second liquid crystal panel, so that the other gap is suppressed while suppressing reflection. Using this, the distance between panels can be adjusted. By ensuring the distance between the panels, the haze value of the diffusion layer can be set low. As a result, the loss of polarization due to the diffusion layer is reduced, leading to an improvement in luminance. Further, by suppressing reflection, a decrease in oblique light transmittance is suppressed, and a decrease in luminance viewing angle is suppressed.

  In the liquid crystal display device according to the present disclosure, a diffusion layer is provided between the first liquid crystal panel on which the first video is displayed and the second liquid crystal panel on which the second video corresponding to the first video is displayed. By arranging the moiré, the moire can be suppressed. Further, by providing a reflection suppression layer between one of the diffusion layer and the first liquid crystal panel and between the diffusion layer and the second liquid crystal panel, the distance between the panels is adjusted while suppressing reflection. It becomes possible. Thereby, the polarization loss in the diffusion layer can be suppressed, and a decrease in the transmittance of oblique light can be suppressed. Therefore, it is possible to improve the luminance and improve the luminance viewing angle.

  The above content is an example of the present disclosure. The effects of the present disclosure are not limited to those described above, and may be other different effects or may include other effects.

1 is a functional block diagram illustrating an overall configuration of a liquid crystal display device according to an embodiment of the present disclosure. It is sectional drawing showing the principal part structure of the liquid crystal display device shown in FIG. It is a schematic diagram for demonstrating the structure of the liquid crystal panel (front side) shown in FIG. It is a schematic diagram for demonstrating the structure of the liquid crystal panel (rear side) shown in FIG. It is a schematic diagram for demonstrating the transmission axis of a polarizing plate. It is sectional drawing showing the principal part structure of the liquid crystal display device which concerns on a comparative example. It is a characteristic view showing an example of the reflectance in the liquid crystal display device shown in FIG. FIG. 3 is a characteristic diagram illustrating an example of reflectance in the liquid crystal display device illustrated in FIG. 2. It is a characteristic view showing the relationship (brightness viewing angle) of the transmission ratio with respect to a viewing angle. It is a schematic diagram for demonstrating the relationship between a polarization component and a transmission axis. It is sectional drawing showing the principal part structure of the liquid crystal display device which concerns on a modification.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
1. Embodiment (an example of a liquid crystal display device in which a diffusion layer is disposed between two liquid crystal panels and a reflection suppressing layer is provided between the diffusion layer and the front liquid crystal panel)
2. Modified example (example in which a reflection suppressing layer is provided between the diffusion layer and the rear liquid crystal panel)

<Embodiment>
[Constitution]
FIG. 1 illustrates an overall configuration of a liquid crystal display device (liquid crystal display device 1) according to an embodiment of the present disclosure. The liquid crystal display device 1 performs video display using a plurality of (here, two) liquid crystal display panels (liquid crystal panels 10 and 20) based on a video signal Din input from the outside. The liquid crystal display device 1 includes, for example, liquid crystal panels 10 and 20, a backlight 30 (light source unit), a timing control unit 40, a video signal processing unit 41, a backlight driving unit 130, and panel driving units 110 and 120. Is provided.

  The liquid crystal panel 10 (first liquid crystal panel) includes a plurality of pixels P1 (first pixels) arranged in a matrix, for example. The liquid crystal panel 10 performs color image display, for example, by modulating incident light based on a video signal Din (specifically, a video signal D1 for the liquid crystal panel 10 based on the video signal Din). The pixel P1 of the liquid crystal panel 10 corresponds to, for example, one of R (red), G (green), and B (blue) subpixels, and these three subpixels R, G, and B A set of pixels constitutes one pixel. The liquid crystal panel 10 desirably has a larger number of pixels (higher resolution) than the liquid crystal panel 20. As an example, a pixel with 3840 × 2160 pixels can be used.

  The liquid crystal panel 20 (second liquid crystal panel) is disposed between the liquid crystal panel 10 and the backlight 30, and includes a plurality of pixels P2 (second pixels) disposed in a matrix, for example. The liquid crystal panel 20 modulates the light emitted from the backlight 30 based on the video signal Din (specifically, the video signal D2 for the liquid crystal panel 20 based on the video signal Din), for example, monochrome (black and white). The video display is performed. The liquid crystal panel 20 desirably has a smaller number of pixels than the liquid crystal panel 10 (has low resolution). For example, a pixel having 1920 × 1080 pixels can be used. The liquid crystal panel 20 does not necessarily have a lower resolution than the liquid crystal panel 10 and may have a resolution comparable to that of the liquid crystal panel 10. Further, not a monochrome image, but a color image may be displayed as in the liquid crystal panel 10. However, by reducing the resolution of the liquid crystal panel 20 and displaying monochrome images, the transmittance can be improved, which is advantageous for improving the luminance.

  The backlight 30 is a light source that emits light toward the liquid crystal panels 10 and 20, and includes a plurality of LEDs (Light Emitting Diodes), CCFLs (Cold Cathode Fluorescent Lamps), and the like. The backlight 30 is driven by a backlight driving unit 130 so that a lighting state and a light-off state are controlled.

  The timing control unit 40 controls the driving timing of the panel driving units 110 and 120, and the video signal (D1) for the liquid crystal panel 10 is sent to the panel driving unit 110, and the video signal (D2) for the liquid crystal panel 20 is panel driven. It supplies to each part 120.

  The video signal processing unit 41 generates a video signal D1 for the liquid crystal panel 10, a video signal D2 for the liquid crystal panel 20, and a control signal for the backlight driving unit 130 based on the input video signal Din. It is.

  The panel driving unit 110 includes a scanning line driving circuit 111 and a signal line driving circuit 112. The scanning line driving circuit 111 drives the plurality of pixels P1 of the liquid crystal panel 10 line-sequentially according to timing control by the timing control unit 40. The signal line driving circuit 112 supplies a video voltage based on the video signal D1 supplied from the timing control unit 40 to each pixel P1. Specifically, a video signal that is an analog signal is generated by performing D / A (digital / analog) conversion on the video signal D1, and is output to each pixel.

  The panel driving unit 120 includes a scanning line driving circuit 121 and a signal line driving circuit 122. The scanning line driving circuit 121 drives the plurality of pixels P <b> 2 of the liquid crystal panel 20 line-sequentially according to timing control by the timing control unit 40. The signal line driving circuit 122 supplies a video voltage based on the video signal D2 supplied from the timing control unit 40 to each pixel P2. Specifically, a video signal that is an analog signal is generated by performing D / A (digital / analog) conversion on the video signal D2, and is output to each pixel.

(Detailed configuration of LCD panel)
FIG. 2 illustrates a configuration of a main part of the liquid crystal display device 1. Thus, in the liquid crystal display device 1, the liquid crystal panel 20 and the liquid crystal panel 10 are laminated in order from the backlight 30 side, and the upper surface of the liquid crystal panel 10 is the display surface A (most viewing side surface). It has become. In the present embodiment, the liquid crystal panel 10 and the liquid crystal panel 20 are arranged apart from each other, and a diffusion layer (diffusion layer 50) is arranged between the liquid crystal panel 10 and the liquid crystal panel 20. . A reflection suppression layer 60 is provided between one of the liquid crystal panels 10 and 20 (here, the liquid crystal panel 10) and the diffusion layer 50. On the other hand, between the diffusion layer 50 and the liquid crystal panel 20,
It is an air layer (gap 1S). In the following description, the display surface side is described as the front side and the backlight 30 side (rear side).

  The distance between the liquid crystal panel 10 and the liquid crystal panel 20 (inter-panel distance S) is not particularly limited. For example, the diffusion degree (haze value) of the diffusion layer 50, the width of the pixel P1 of the liquid crystal panel 10, and the liquid crystal panel 20 In consideration of the width of the pixel P2 and the like, it is set to an appropriate size so as to obtain a desired image quality (for example, moire, luminance, and luminance viewing angle). In particular, by appropriately setting the inter-panel distance S and the haze value of the diffusion layer 50, it is possible to suppress moire while suppressing a decrease in luminance.

  In the liquid crystal panel 10, a liquid crystal layer 13 is sealed between a drive substrate 12 and a counter substrate 14 that are disposed to face each other. A polarizing plate 11 a is bonded to the light incident side of the driving substrate 12, and a polarizing plate 11 b is bonded to the light emitting side of the counter substrate 14. In the liquid crystal panel 20, a liquid crystal layer 23 is sealed between a drive substrate 22 and a counter substrate 24 that are disposed to face each other. A polarizing plate 21 a is bonded to the light incident side of the driving substrate 22, and a polarizing plate 21 b is bonded to the light emitting side of the counter substrate 24.

  FIG. 3A is a schematic diagram for explaining the configuration of the liquid crystal panel 10. In the liquid crystal panel 10, the pixel electrode 113 is provided on the driving substrate 12 for each pixel P <b> 1. On the pixel electrode 113, the alignment film 114a, the liquid crystal layer 13, the alignment film 114b, and the counter electrode 115 are arranged in this order. On the counter electrode 115, a color filter 116A and a black matrix 116B are formed. The counter substrate 14 (not shown in FIG. 3A) is disposed on the color filters 116A and the black matrix 116B. Thus, in the liquid crystal panel 10, the liquid crystal layer 13 is sandwiched between the plurality of pixel electrodes 113 and one counter electrode 115. When displaying an image, a voltage is applied to the liquid crystal layer 13 through the pixel electrode 113 and the counter electrode 115 for each pixel P1.

  FIG. 3B is a schematic diagram for explaining the configuration of the liquid crystal panel 20. In the liquid crystal panel 20, similarly to the liquid crystal panel 10 described above, the pixel electrode 123 is provided on the drive substrate 22 for each pixel P <b> 2. On the pixel electrode 123, the alignment film 124a, the liquid crystal layer 23, the alignment film 124b, and the counter electrode 125 are arranged in this order. A counter substrate 24 (not shown in FIG. 3B) is disposed on the counter electrode 125. Thus, also in the liquid crystal panel 20, the liquid crystal layer 23 is sandwiched between the plurality of pixel electrodes 123 and one counter electrode 125. When displaying an image, a voltage is applied to the liquid crystal layer 23 through the pixel electrode 123 and the counter electrode 125 for each pixel P2. However, in the liquid crystal panel 20, it is desirable that a color filter is not formed and a monochrome image is displayed as described above. This is because light loss is reduced, which is advantageous for higher brightness.

  The drive substrates 12 and 22 are made of, for example, a glass substrate, and have, for example, a rectangular surface shape (surface shape parallel to the display screen). The drive substrate 12 is formed with a pixel circuit (including a thin film transistor (TFT) and a capacitor) for driving the pixel P1. The counter substrates 14 and 24 are made of, for example, a glass substrate.

  The pixel electrodes 113 and 123 are arranged in a matrix on the drive substrates 12 and 22. The pixel electrodes 113 and 123 are made of a transparent conductive film, for example. As the transparent conductive film, for example, an oxide semiconductor such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or IGZO (indium, gallium, zinc-containing oxide) is used. it can.

  The liquid crystal layers 13 and 23 have a function of controlling the transmittance of light transmitted therethrough according to the supplied video voltage. The liquid crystal layers 13 and 23 are displayed by, for example, VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, ECB (Electrically controlled birefringence) mode, FFS (Fringe Field Switching) mode, or IPS (In Plane Switching) mode. Includes liquid crystal to be driven.

The alignment films 114a, 114b, 124a, and 124b are for controlling the alignment of the liquid crystal layers 13 and 23, and are made of, for example, an inorganic alignment film such as silicon oxide (SiO ₂ ).

  The counter electrodes 115 and 125 are electrodes common to all the pixels, and the constituent material includes the same transparent conductive film as the pixel electrodes 113 and 123.

  FIG. 4 shows an example of the transmission axis (polarization transmission axis) of the polarizing plates 11a, 11b, 21a, and 21b. Thus, for example, the polarizing plate 21a of the liquid crystal panel 20 and the polarizing plate 11b of the liquid crystal panel 10 transmit the polarizing component in the vertical direction (Y direction), and the polarizing plate 21b of the liquid crystal panel 20 and the polarizing plate 11a of the liquid crystal panel 10 are transmitted. Are set to transmit the polarization component in the horizontal direction (X direction). The transmission axes of these polarizing plates 11a, 11b, 21a, and 21b may be set as appropriate according to the driving mode of the liquid crystal layers 13 and 23. For example, a set of polarizing plates having a crossed Nicols relationship is used. Two sets are arranged. Note that either one of the polarizing plate 11a and the polarizing plate 21b (for example, the polarizing plate 21b) may be eliminated and a total of three configurations may be used.

  Among these polarizing plates 11a, 11b, 21a, and 21b, the transmission axis of the polarizing plate provided on the light incident side of the most viewing side liquid crystal panel is along the horizontal direction (horizontal direction of polarizing plate, X direction). It is desirable. For example, as in this embodiment, the transmission axis of the polarizing plate 11a of the liquid crystal panel 10 may be in the horizontal direction. Although this will be described later in detail, this is advantageous for the luminance viewing angle. In addition, although two liquid crystal panels 10 and 20 are used here, the same can be said even when there are three or more liquid crystal panels. Examples of the constituent material of the polarizing plates 11a, 11b, 21a, and 21b include TAC (triacetyl cellulose), COP (cycloolefin resin), and PET (polyethylene terephthalate).

  As shown in FIG. 2, the diffusion layer 50 may be disposed at any position between the liquid crystal panel 10 and the liquid crystal panel 20, but preferably on the side close to the liquid crystal panel 10 (front side). Has been placed. For example, when the reflection suppression layer 60 has adhesiveness, the diffusion layer 50 may be bonded to the liquid crystal panel 10 via the reflection suppression layer 60. This is because moire can be more effectively suppressed and the sharpness can be enhanced when the diffusion layer 50 is disposed on the front side than on the rear side.

  The higher the haze value of the diffusion layer 50, the more effectively the moire can be suppressed. However, the higher the haze value, the lower the luminance. The haze value of the diffusion layer 50 can be set to, for example, about 70% or more according to other parameters.

  Although the structure of the diffusion layer 50 is not particularly limited, an example is a diffusion film including beads or pillars randomly distributed on or inside the resin film. In such a diffusion film, the haze value can be set by adjusting the film material, the material or concentration of beads or pillars, and the like. However, in the present embodiment, the reflection suppressing layer 60 is formed adjacent to the diffusion layer 50. For this reason, a diffusion film of a type that exhibits diffusivity by containing beads and pillars inside is used rather than a type that exhibits diffusivity by being dispersed on the surface (due to the uneven shape of the surface). It is desirable. This is because even if the antireflection layer 60 is adjacent, it is easy to exhibit the diffusing ability. In addition, as the diffusion layer 50, the diffusion film as described above may be used as a single sheet (single layer), or a laminate of a plurality of sheets may be used.

  The reflection suppression layer 60 is provided, for example, so as to fill a gap between the liquid crystal panel 10 and the diffusion layer 50 and is made of a transparent material. As the transparent material, a material having no optical anisotropy and a refractive index of about 1.3 to 1.7 can be used. Desirably, the refractive index of the reflection suppressing layer 60 may be equal to the refractive index of the adjacent polarizing plate (here, the polarizing plate 11a). This is because reflection can be effectively suppressed. As a constituent material of the reflection suppressing layer 60, a transparent material having a refractive index similar to that of TAC, COP, and PET, which are constituent materials of the polarizing plate 11a described above, for example, UV curable resin, OCA (Optically Clear Adhesive) film, Examples thereof include an adhesive gel. Instead of the diffusion layer 50 and the reflection suppression layer 60 as described above, a material layer having both functions of the diffusion layer 50 and the reflection suppression layer 60 may be provided. For example, a material in which pillars are randomly dispersed in a UV curable resin or the like can simultaneously exhibit a diffusion function and a reflection suppression function.

  The thickness S1 of the reflection suppression layer 60 is desirably as small as possible from the viewpoint of suppressing moire, that is, the diffusion layer 50 is preferably disposed at a position closer to the liquid crystal panel 10. On the other hand, although details will be described later, it is desirable that the inter-panel distance S is large from the viewpoint of luminance. In the present embodiment, since the gap 1S is between the diffusion layer 50 and the liquid crystal panel 20, the thickness (distance between the diffusion layer 50 and the liquid crystal panel 20) S2 of the gap 1S is set to the antireflection layer 60. It is possible to ensure the inter-panel distance S by setting it to be larger than the thickness S1.

[Action, effect]
In the liquid crystal display device 1, as shown in FIG. 1, when the video signal Din is input from the outside to the video signal processing unit 41, the video signal processing unit 41 performs predetermined image processing and also the liquid crystal panel 10. Video signal D1 and video signal D2 for liquid crystal panel 20 are generated and supplied to timing controller 40. Under the control of the timing control unit 40, the panel driving unit 110 is driven to drive the pixels P1 of the liquid crystal panel 10 line-sequentially, and a video voltage based on the video signal D1 is supplied to each pixel P1. Further, in synchronization with the drive timing of the liquid crystal panel 10, the panel drive unit 120 is driven, the pixels P2 of the liquid crystal panel 20 are driven line-sequentially, and a video voltage based on the video signal D2 is supplied to each pixel P2. The

  Thereby, in the liquid crystal panel 10, the incident light based on the light emitted from the backlight 30 is modulated for each pixel P1 based on the video signal D1, and a color video (high resolution) is displayed. On the other hand, in the liquid crystal panel 20, the light emitted from the backlight 30 is modulated for each pixel P2 based on the video signal D2. At this time, the liquid crystal panel 20 displays a monochrome image (low resolution) corresponding to the display image on the liquid crystal panel 10. In other words, the image displayed on the liquid crystal panel 20 is a monochrome image of the color image displayed on the liquid crystal panel 10 and further reduced in resolution. An observer (viewer) sees a display image superimposed on each of the liquid crystal panels 10 and 20.

  In this way, by performing video display using the liquid crystal panels 10 and 20, the black luminance is reduced (black is expressed more black) and contrast than when video display is performed using a single liquid crystal panel. The ratio becomes high. For example, a high contrast ratio of 100,000 to 1 (100,000: 1) can be realized. In addition, the so-called backlight partial drive (local dimming) system can realize super multi-division local dimming, which is difficult to realize. That is, it is possible to perform local dimming with the resolution of the liquid crystal panel 20 as the number of divisions.

  Further, the image quality can be improved by disposing the diffusion layer 50 between the liquid crystal panels 10 and 20. When a plurality of liquid crystal panels are arranged in an overlapping manner and video display is performed on each liquid crystal panel, moire is likely to occur. However, the arrangement of the diffusion layer 50 suppresses the occurrence of moire and leads to higher image quality.

  On the other hand, when the diffusion layer 50 is disposed for the purpose of suppressing moire, there is a concern that the luminance may decrease due to the loss of polarization in the diffusion layer 50. Further, the front direction (direction perpendicular to the display surface A) is caused by the arrangement of the liquid crystal panels 10 and 20 being overlapped, the occurrence of reflection, or the phase difference of the diffusion layer 50 having an angle dependency. ), The light transmittance in an oblique direction tilted from (1) decreases, and the luminance viewing angle decreases.

  Here, FIG. 5 shows a main configuration of a liquid crystal display device according to a comparative example. In this liquid crystal display device, the diffusion layer 50 is disposed between the liquid crystal panels 10 and 20 as in the present embodiment. However, the gap between the diffusion layer 50 and the liquid crystal panels 10 and 20 is an air layer (air gap 101S1). , 101S2), which is different from the liquid crystal display device 1 of the present embodiment. In the case of such a laminated structure of the comparative example, the light emitted from the backlight 30 is easily reflected at the interface between the gap 101S1 and the diffusion layer 50 and at the interface between the gap 101S2 and the polarizing plate 11a (reflected light X1, X2 Are likely to occur). For this reason, the transmittance is lowered and the luminance is lowered as compared with the case where video display is performed using one liquid crystal panel.

  On the other hand, in the present embodiment, the reflection suppressing layer 60 is provided between the diffusion layer 50 and the liquid crystal panel 10, thereby reducing the reflected light X2 on the back surface of the polarizing plate 11a (the back surface of the liquid crystal panel 10). The Thereby, the transmittance is higher than that of the comparative example, which leads to an improvement in luminance.

  In addition, while the antireflection layer 60 is provided between the liquid crystal panel 10 and the diffusion layer 50, a gap 1 </ b> S is provided between the diffusion layer 50 and the liquid crystal panel 20. Accordingly, the inter-panel distance S can be adjusted using the gap 1S while suppressing reflection. As described above, since it is desirable that the diffusion layer 50 be disposed at a position closer to the liquid crystal panel 10 in terms of moire suppression, the thickness of the reflection suppression layer 60 is preferably as small as possible. For this reason, the magnitude | size of the distance S between panels can be set by adjusting the thickness of the space | gap 1S. If the inter-panel distance S can be secured with a certain size, the effect of suppressing moire can be obtained even if the haze value of the diffusion layer 50 is set low. As a result, the loss of polarization due to the diffusion layer 50 is reduced, leading to an improvement in luminance. Further, by suppressing reflection, a decrease in oblique light transmittance is suppressed, and a decrease in luminance viewing angle is suppressed.

  As an example, FIG. 6 shows the relationship of the reflectance with respect to the incident angle in the liquid crystal display device of the comparative example, and FIG. 7 shows the relationship of the reflectance with respect to the incident angle in the liquid crystal display device 1 of the present embodiment. However, the refractive index of the reflection suppressing layer 60 is 1.49, and a TAC substrate (refractive index 1.50) is assumed as the polarizing plate 11a. Thus, in this Embodiment, it turns out that the reflectance is reduced compared with the comparative example.

  Further, in the comparative example (FIG. 6), it can be seen that the reflectance increases as the incident angle increases, and the angle dependency occurs in the transmittance. In addition, there is a difference in reflectance between p-polarized light (solid line) and s-polarized light (broken line), and it can be seen that the reflectance of p-polarized light is lower than that of s-polarized light. Further, the angle dependency of the reflectance is different between p-polarized light and s-polarized light. As shown in FIG. 8, the angle dependency of the transmittance of the liquid crystal panel increases as the number of liquid crystal panels increases.

  On the other hand, in the present embodiment (FIG. 7), it can be seen that there is almost no change in the reflectance with respect to the incident angle, and the angle dependency of the transmittance hardly occurs. In addition, the reflectance of p-polarized light and the reflectance of s-polarized light show substantially the same tendency.

  FIG. 9 shows images of p-polarized light (transmission) and s-polarized light (reflection) incident on the polarizing plate 11a. In the liquid crystal display device 1, a total of two sets of polarizing plates (a set of polarizing plates 11a and 11b and a set of polarizing plates 21a and 21b) are arranged. Of these, the light incident side of the viewing-side liquid crystal panel ( The transmission axis of the polarizing plate provided on the rear side), that is, the polarizing plate 11a is along the horizontal direction. Here, in a display application, it is desirable that the luminance viewing angle in the horizontal direction is good. As in the present embodiment, the luminance viewing angle in the horizontal direction is improved by matching the transmission axis of the polarizing plate 11a with the electric field vibration direction of the p-polarized light in the horizontal direction.

  Further, in the present embodiment, the liquid crystal panel 20 does not have a color filter and displays a monochrome image, so that there is no light absorption by the color filter, which is advantageous for higher luminance.

  In addition, since the liquid crystal panel 20 has a lower resolution than the liquid crystal panel 10, the luminance can be increased as compared with the case where the resolution is comparable to the liquid crystal panel 10. Further, it is advantageous for suppressing moire.

  As described above, in the present embodiment, moire can be suppressed by disposing the diffusion layer 50 between the liquid crystal panel 10 and the liquid crystal panel 20. Further, by providing the reflection suppression layer 60 between the diffusion layer 50 and the liquid crystal panel 10, the distance between the panels can be adjusted while suppressing reflection. Thereby, the haze value in the diffusion layer 50 can be lowered to suppress the disappearance of polarized light and to suppress the decrease in the transmittance of oblique light. Therefore, it is possible to improve the luminance and improve the luminance viewing angle.

  Further, a display suitable for viewing by a large number of people can be realized by improving the luminance viewing angle. In addition, the light emission luminance of the backlight 30 can be lowered, leading to low power consumption.

  Hereinafter, modifications of the above embodiment will be described. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and description is abbreviate | omitted.

<Modification>
FIG. 10 illustrates a cross-sectional configuration of a liquid crystal display device according to a modification. In the above-described embodiment and the like, the reflection suppressing layer 60 is provided between the liquid crystal panel 10 and the diffusion layer 50, and the gap 1S is provided between the liquid crystal panel 20 and the diffusion layer 50. Between the liquid crystal panel 10 and the diffusion layer 50 is a gap 1S. Thus, the reflection suppression layer 60 may be either between the diffusion layer 50 and the liquid crystal panel 10 or between the diffusion layer 50 and the liquid crystal panel 20.

  When the reflection suppression layer 60 is provided between the diffusion layer 50 and the liquid crystal panel 20 as in this modification, the reflected light on the back surface of the diffusion layer 50 out of the light emitted from the backlight 30 (FIG. 5). The reflected light X1) can be reduced. Thereby, the brightness can be improved.

  Further, a gap 1S is formed between the liquid crystal panel 10 and the diffusion layer 50, and the size of the inter-panel distance S can be set using the gap 1S as in the above embodiment. Therefore, substantially the same effect as the above embodiment can be obtained.

  As mentioned above, although several embodiments and modifications have been described, the present disclosure is not limited to these embodiments and the like, and various modifications are possible. For example, in the above-described embodiment and the like, the configuration in which video display is performed using the two liquid crystal panels 10 and 20 is illustrated, but the liquid crystal display device of the present disclosure uses three or more liquid crystal panels. May be.

  In the above-described embodiment and the like, the antireflection layer 60 is provided between one of the diffusion layer 50 and the liquid crystal panel 10 and between the diffusion layer 50 and the liquid crystal panel 20, and the other is a gap. Depending on circumstances, the antireflection layer 60 may be provided both between the diffusion layer 50 and the liquid crystal panel 10 and between the diffusion layer 50 and the liquid crystal panel 20. That is, an air layer may not be formed between the liquid crystal panel 10 and the liquid crystal panel 20. This is an advantageous structure from the viewpoint of suppressing reflection. In this case, two antireflection layers 60 are provided, but these two antireflection layers 60 may be made of the same material or different materials.

  Furthermore, the effect demonstrated in the said embodiment etc. is an example, The other effect may be sufficient and the other effect may be included.

The present disclosure may be configured as follows.
(1)
A light source unit;
A first liquid crystal panel on which a first video based on the video signal is displayed;
A second liquid crystal panel disposed between the light source unit and the first liquid crystal panel and displaying a second video corresponding to the first video;
A diffusion layer disposed between the first liquid crystal panel and the second liquid crystal panel;
A liquid crystal display device comprising: a reflection suppressing layer provided between one of the first and second liquid crystal panels and the diffusion layer.
(2)
The antireflection layer is provided between the first liquid crystal panel and the diffusion layer,
The liquid crystal display device according to (1), wherein there is a gap between the second liquid crystal panel and the diffusion layer.
(3)
The liquid crystal display device according to (2), wherein the reflection suppression layer is provided so as to fill a space between the first liquid crystal panel and the diffusion layer.
(4)
The liquid crystal display device according to (3), wherein the reflection suppression layer is made of a material having transparency and a refractive index of 1.3 to 1.7.
(5)
The liquid crystal display device according to (2), wherein a distance between the diffusion layer and the second liquid crystal panel is larger than a thickness of the reflection suppressing layer.
(6)
A plurality of liquid crystal panels including the first liquid crystal panel and the second liquid crystal panel are disposed,
The transmission axis of the polarizing plate on the light incident side of the liquid crystal panel arranged closest to the viewing side among the plurality of liquid crystal panels is along the horizontal direction of the polarizing plate. Any one of (1) to (5) A liquid crystal display device according to 1.
(7)
The antireflection layer is provided between the second liquid crystal panel and the diffusion layer,
The liquid crystal display device according to any one of (1) to (6), wherein a gap is formed between the diffusion layer and the first liquid crystal panel.
(8)
The liquid crystal display device according to any one of (1) to (7), wherein the second liquid crystal panel has a lower resolution than the first liquid crystal panel.
(9)
The first image is a color image;
The liquid crystal display device according to any one of (1) to (8), wherein the second video is a monochrome video.

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 10,20 ... Liquid crystal panel, 30 ... Backlight, 40 ... Timing control part, 41 ... Video signal processing part, 50 ... Diffusion layer, 60 ... Antireflection layer, 110, 120 ... Panel drive part, 130: Backlight drive unit, P1, P2: Pixel, A: Display surface, S: Distance between panels, 1S: Air gap.

Claims (9)

A light source unit;
A first liquid crystal panel on which a first video based on the video signal is displayed;
A second liquid crystal panel disposed between the light source unit and the first liquid crystal panel and displaying a second video corresponding to the first video;
A diffusion layer disposed between the first liquid crystal panel and the second liquid crystal panel;
A liquid crystal display device comprising: a reflection suppressing layer provided between one of the first and second liquid crystal panels and the diffusion layer. The antireflection layer is provided between the first liquid crystal panel and the diffusion layer,
The liquid crystal display device according to claim 1, wherein a gap is provided between the second liquid crystal panel and the diffusion layer. The liquid crystal display device according to claim 2, wherein the reflection suppression layer is provided so as to fill a space between the first liquid crystal panel and the diffusion layer. The liquid crystal display device according to claim 3, wherein the reflection suppression layer is made of a material having transparency and a refractive index of 1.3 to 1.7. The liquid crystal display device according to claim 2, wherein a distance between the diffusion layer and the second liquid crystal panel is larger than a thickness of the reflection suppressing layer. A plurality of liquid crystal panels including the first liquid crystal panel and the second liquid crystal panel are disposed,
The liquid crystal display device according to claim 1, wherein a transmission axis of a polarizing plate on a light incident side of a liquid crystal panel arranged closest to the viewing side among the plurality of liquid crystal panels is along a horizontal direction of the polarizing plate. The antireflection layer is provided between the second liquid crystal panel and the diffusion layer,
The liquid crystal display device according to claim 1, wherein a gap is formed between the diffusion layer and the first liquid crystal panel. The liquid crystal display device according to claim 1, wherein the second liquid crystal panel has a lower resolution than the first liquid crystal panel. The first image is a color image;
The liquid crystal display device according to claim 1, wherein the second video is a monochrome video.

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