WO2007086168A1

WO2007086168A1 - Liquid crystal display and television receiver

Info

Publication number: WO2007086168A1
Application number: PCT/JP2006/319946
Authority: WO
Inventors: Tsuyoshi Tokuda; Yoshiki Takata; Toshihide Tsubata; Naoshi Yamada; Shigeaki Mizushima
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-01-26
Filing date: 2006-10-05
Publication date: 2007-08-02

Abstract

In a liquid crystal display (100), first and second liquid crystal panels are superposed on one the other. In each of the two liquid crystal panels, a color filter (21) is provided to an insulating substrate (10) constituting the liquid crystal panel. In such a way, a liquid crystal display of high display definition having an improved color reproduction range when two or more liquid crystal panels are superposed can be provided. Since liquid crystal display (100) exhibits a greatly improved contrast, it can be adaptable to a television receiver and a broadcasting monitor.

Description

Specification

Liquid crystal display device and television receiver

Technical field

The present invention relates to a liquid crystal display device with improved contrast and a television receiver including the same.

Background art

[0002] There are various techniques disclosed in the following Patent Documents 1 to 7 as techniques for improving the contrast of a liquid crystal display device.

[0003] Patent Document 1 discloses a technique for improving the contrast ratio by appropriately adjusting the content and specific surface area of the yellow pigment in the pigment component of the color filter. As a result, it is possible to improve the problem that the contrast ratio of the liquid crystal display device is lowered due to the scattering and depolarization of the polarized light molecules of the color filter. According to the technique disclosed in Patent Document 1, the contrast ratio of the liquid crystal display device is improved from 280 to 420.

[0004] Patent Document 2 discloses a technique for improving the contrast ratio by increasing the transmittance and the degree of polarization of a polarizing plate. According to the technique disclosed in Patent Document 2, the contrast ratio of the liquid crystal display device is improved from 200 to 250.

[0005] Further, Patent Document 3 and Patent Document 4 disclose a technique for improving contrast in a guest-host method using the light absorptivity of a dichroic dye.

[0006] Patent Document 3 describes a method for improving contrast by a structure in which a guest-host liquid crystal cell has two layers and a 1Z4 wavelength plate is sandwiched between the two layers of cells. In Patent Document 3,

It is disclosed that no polarizing plate is used.

[0007] Patent Document 4 discloses a liquid crystal display element of a type in which a dichroic dye is mixed with a liquid crystal used in a dispersion type liquid crystal system. Patent Document 4 describes that the contrast ratio is 101.

[0008] However, the techniques disclosed in Patent Document 3 and Patent Document 4 have a lower contrast than other methods, and in order to further improve the contrast, the light absorption of the dichroic dye is improved. Strength that requires increasing the dye content and increasing the thickness of the guest-host liquid crystal cell In any case, new problems such as technical problems, reduced reliability and poor response characteristics arise.

[0009] Further, Patent Document 5 and Patent Document 6 disclose a contrast improvement method using an optical compensation method, in which a liquid crystal display panel and a liquid crystal panel for optical compensation are provided between a pair of polarizing plates.

[0010] In Patent Document 5, in the STN method, the contrast ratio of the display cell, the liquid crystal cell for differential optical compensation, and the retardation is improved from 14 to 35! /.

[0011] In Patent Document 6, a liquid crystal cell for optical compensation is installed to compensate for the wavelength dependence of a TN liquid crystal display cell during black display, and the contrast ratio is improved from 8 to 100. ing.

[0012] However, with the techniques disclosed in each of the above patent documents, a force that improves the contrast ratio by a factor of 2 to 10 is obtained. The absolute value of the contrast ratio is 35 to 420. It is a degree.

[0013] As a technique for improving the contrast, for example, Patent Document 7 discloses a composite liquid crystal display in which two liquid crystal panels are overlapped so that each polarizing plate forms a cross-coll. An apparatus is disclosed. Patent Document 7 describes that a contrast ratio of one panel is 100, and the contrast ratio can be expanded to about 3 to 4 digits by superimposing two panels.

Patent Document 1: Japanese Published Patent Publication “JP 2001-188120 (Publication Date: July 10, 2001)”

Patent Document 2: Japanese Published Patent Publication “Japanese Patent Laid-Open No. 2002-90536 (Publication Date: March 27, 2002)”

Patent Document 3: Japanese Patent Publication “JP-A 63-25629 (Publication Date: February 3, 1988)”

Patent Document 4: Japanese Patent Publication “Japanese Patent Laid-Open No. 5-2194 (Publication Date: January 8, 1993)”

Patent Document 5: Japanese Published Patent Publication “Japanese Patent Laid-Open No. 64-49021” (Publication Date: February 1989) Patent Document 6: Japanese Patent Publication “Japanese Patent Laid-Open No. 2-23 (Publication Date: January 5, 1990) J

Patent Document 7: Japanese Patent Publication “JP-A-5-88197 (Publication Date: April 9, 1993)”

Disclosure of the invention

[0014] However, although Patent Document 7 can improve the contrast by overlapping two liquid crystal panels, it is particularly considered for improving the color reproduction range at the time of display. If the display image is poor in color reproduction, the display quality is low, and the image becomes!

[0015] The present invention has been made in view of the above-described problems, and an object of the present invention is to improve the color reproduction range when two or more liquid crystal panels are stacked, and to achieve high display quality and liquid crystal display. To realize the device.

In general, in order to improve the color reproduction range in a liquid crystal panel, that is, to make the absorption spectrum in a color filter (CF) steep, the CF film thickness is increased or the CF pigment concentration is increased. It is possible to raise.

The CF is generally formed by a photolithography method using a photosensitive material. If the film thickness of CF is increased, light does not reach the substrate surface, so that photocuring in the vicinity of the substrate interface is insufficient and it becomes difficult to obtain a desired pattern shape. Especially at the pattern edge, the coverage of the counter electrode such as ITO is worse. In addition, when the pigment concentration of the CF material is increased, the ratio of the resin component that contributes to curing is reduced by that amount, and a desired pattern shape can be obtained as in the case of increasing the film thickness. It becomes difficult.

Accordingly, there is a limit to the improvement of the color reproduction range in one CF.

[0019] Therefore, as a result of intensive studies to solve the above-mentioned problems, the inventors of the present application have provided a CF 1 sheet by providing two or more CFs in a liquid crystal display device in which two or more liquid crystal panels are superimposed. It has been found that a spectral transmittance steeper than in the case of can be obtained.

That is, in order to solve the above-described problem, the liquid crystal display device according to the present invention is a liquid crystal display device in which two or more liquid crystal panels are stacked, and at least two of the plurality of liquid crystal panels are used. The liquid crystal panel has a color frame on the insulating substrate constituting the liquid crystal panel. It is characterized by the fact that a filter is provided.

[0021] According to the above configuration, in at least two of the plurality of liquid crystal panels, the color filter is provided on the insulating substrate that constitutes the liquid crystal panel, so that the superimposed liquid crystal The panel will transmit light through the color filter at least twice.

In this case, as described above, by providing two or more color filters, it is possible to obtain a spectral transmittance that is steeper than in the case of a single color filter, so that color mixing is less likely to occur. The color reproduction range can be improved.

[0023] Further, the polarization absorbing layer may be provided in a cross-col relationship with the liquid crystal panel interposed therebetween.

In this case, since the polarization absorbing layers of the liquid crystal panels are in a cross-col relationship with each other, the contrast ratio can be greatly improved.

[0025] Therefore, it is possible to obtain a display image with excellent color reproducibility, a high contrast ratio, and a very high display quality.

[0026] The insulating substrates provided with the color filters may be disposed adjacent to each other.

[0027] Furthermore, the thickness of at least one insulating substrate on the side adjacent to each other of the stacked liquid crystal panels may be thinner than the thickness of the insulating substrate on the side not adjacent to each other.

[0028] In this case, since the distance between the color filters can be shortened, color moire caused by parallax caused by the separation of the color filters can be reduced, and the display quality can be improved. .

[0029] The number of the insulating substrates provided with the color filter may be two, and the insulating substrate may be an active matrix substrate of one liquid crystal panel and an insulating substrate opposite to the active matrix substrate.

[0030] Also in this case, since the distance between the color filters can be shortened, color moire due to parallax caused by the separation of the color filters can be reduced, and the display quality can be improved. it can. [0031] Further, a light diffusion layer having light diffusibility may be provided on at least one of the plurality of the liquid crystal panels that are superposed.

[0032] According to the above configuration, the light diffusing layer having light diffusibility is provided on at least one of the plurality of liquid crystal panels that are overlaid, so that the light transmitted through the light diffusing layer is spatially blurred. be able to. As a result, for example, it is possible to suppress the strength of asynchronous interference between fine structures having the same period of adjacent panels (such as a bus line, a black matrix, and an alignment control protrusion). As a result, it is possible to suppress the occurrence of moiré due to structural interference, and thus it is possible to prevent display quality from being deteriorated due to the occurrence of moiré.

[0033] The light diffusion layer may be provided on the display surface side of the superimposed liquid crystal panel.

[0034] In this case, the moiré period information generated in the superimposed liquid crystal panel is erased or relaxed by the light diffusing layer oozing, thereby preventing the moiré from being observed.

[0035] The light diffusing layer is provided between the stacked liquid crystal panels! /!

In this case, the periodic information of the fine structure of the lower panel is erased or relaxed by causing the light diffusion layer to bleed, and the generation of moire can be prevented.

[0037] The light diffusion layer may be provided between the display surface side of the overlapped liquid crystal panel and the overlapped liquid crystal panel.

[0038] In this case, as compared with the case where the light diffusion layer is provided only between the stacked liquid crystal panels.

Therefore, it is possible to reduce a decrease in contrast due to depolarization due to moiré countermeasures.

[0039] At least two polarization absorption layers may be provided between the stacked liquid crystal panels, and a light diffusion layer may be provided between the at least two polarization absorption layers! /.

[0040] In this case, it is possible to prevent the bias caused by diffusion between the panels, and it is difficult to cause a decrease in contrast due to the moire countermeasure.

[0041] Further, in the liquid crystal display device having the above-described configuration, an illumination device that irradiates the superimposed liquid crystal panel with a force light opposite to the display surface is provided, and the illumination device transmits visible light. It has a light source having a peak in the green region, and the wavelength of the peak is 505ηπ! It is preferably in the range of ˜540 nm.

[0042] According to the above configuration, the peak wavelength in the green region of visible light is in the range of 505 nm to 540 nm. By using the light source in the enclosure, it is possible to reduce the mixing of green with other colors (blue and red).

Therefore, the color reproduction range can be improved, and as a result, the display quality of the display image can be improved. A more preferable wavelength of the peak in the green region is 520 nm.

[0044] The phosphor composition capable of improving the color reproduction range includes BaMgAl 2 O 3

There are 10 17.

[0045] A method for driving a liquid crystal display device according to the present invention is a method for driving a liquid crystal display device in which each of the liquid crystal panels of the liquid crystal display device having the above-described structure outputs image data based on a video source. When the outermost LCD panel is the first LCD panel, the γ value of the image data output from the LCD is γ = G (X) out

<X is an arbitrary gradation>, γ = the image data output from the first LCD panel. (X), γ = G (x) of image data output from other LCD panel

2 2, out of at least one gradation X γ = G (X) 1S G (X) = G (X) + G (X) and G (X)> G (X) 1 2 1 2 Characterized by satisfying relationships

According to the above configuration, each polarization absorption layer has a cross-col relationship with the polarization absorption layer of the adjacent liquid crystal panel. For example, in the front direction, the transmission axis direction of the polarization absorption layer This leakage light can be cut off by the absorption axis of the next polarization absorbing layer. Further, in the oblique direction, even if the Nicol angle, which is the intersection angle of the polarization axes of adjacent polarization absorbing layers, collapses, no increase in the amount of light due to light leakage is observed. In other words, black is less likely to float against the widening of the Nicol angle at an oblique viewing angle.

[0046] From the above, when two or more liquid crystal panels are stacked, at least three polarization absorbing layers are provided. In other words, it is possible to significantly improve the shutter performance in both the front and diagonal directions by using three polarization absorbing layers and arranging them in crossed Nicols. Thereby, the contrast can be greatly improved.

[0047] The γ value of the image data output from the liquid crystal display device is γ = G (x) <x is an arbitrary out

At least one gradation when 画像 = G (x) of the image data output from the first LCD panel and γ = G (x) of the image data output from another liquid crystal panel In X Γ = G (X) force G (X) = G (X) + G (X) and satisfies the relationship of G (X)> G (X) out 1 2 1 2

As a result, saturation reduction can be suppressed and a good display can be obtained.

[0048] The first panel may be a color panel, and at least one of the other second panels may be a monochrome panel.

[0049] As a more specific process, the following process is preferable.

[0050] The gradation power of one pixel of the monochrome liquid crystal panel is set to the gradation corresponding to the maximum gradation signal among the pixel signals constituting one picture element of the video source.

[0051] The image data output from the monochrome liquid crystal panel is smoothed.

[0052] Further, the vicinity of the black gradation X may be G (X) <G (X).

2 1 2 2 2

[0053] Further, the value of γ of the image data output from the first panel may be G (χ)> 0 (not 0! /) At all gradations! / ,.

[0054] Further, in the gradation X, it is preferable that G (X) ≥ 1.8.

[0055] A liquid crystal display device of the present invention is used as a display device in a television receiver including a tuner unit that receives a television broadcast and a display device that displays the television broadcast received by the tuner unit. Can be used.

[0056] As described above, the liquid crystal display device according to the present invention is a liquid crystal display device in which two or more liquid crystal panels are overlapped, and at least two of the plurality of liquid crystal panels include the liquid crystal panels. A color filter is provided on the insulating substrate that constitutes the liquid crystal panel.

[0057] According to the above configuration, at least two liquid crystal panels out of the plurality of liquid crystal panels are arranged in such a manner that the color filter is provided on the insulating substrate that constitutes the liquid crystal panel. In the combined liquid crystal panel, light is transmitted through the color filter at least twice, and a steeper spectral transmittance can be obtained than in the case of a single color filter, so that color mixing is less likely to occur. As a result, it is possible to obtain a display image with a high display quality with a greatly improved color reproduction range.

Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention. 2 is a diagram showing the positional relationship between a polarizing plate and a panel in the liquid crystal display device shown in FIG.

3 is a plan view of the vicinity of a pixel electrode of the liquid crystal display device shown in FIG.

4] FIG. 4 is a schematic configuration diagram of a drive system that drives the liquid crystal display device shown in FIG.

[5] FIG. 5 is a diagram showing a connection relationship between the driver of the liquid crystal display device shown in FIG. 1 and a panel drive circuit.

6 is a schematic configuration diagram of a knocklight included in the liquid crystal display device shown in FIG.

FIG. 7 is a block diagram of a display controller that is a drive circuit for driving the liquid crystal display device shown in FIG.

FIG. 8 is a schematic cross-sectional view of a liquid crystal display device with one liquid crystal panel.

FIG. 9 is a diagram showing the positional relationship between a polarizing plate and a panel in the liquid crystal display device shown in FIG.

[10 (a)] is a diagram for explaining the principle of contrast improvement.

[10 (b)] is a diagram for explaining the principle of contrast improvement.

[10 (c)] is a diagram for explaining the principle of contrast improvement.

[11 (a)] is a diagram for explaining the principle of contrast improvement.

[11 (b)] is a diagram for explaining the principle of contrast improvement.

[11 (c)] is a diagram for explaining the principle of contrast improvement.

[11 (d)] is a diagram for explaining the principle of contrast improvement.

[12 (a)] is a diagram for explaining the principle of contrast improvement.

[12 (b)] is a diagram for explaining the principle of contrast improvement.

[12 (c)] is a diagram for explaining the principle of contrast improvement.

[13 (a)] is a diagram for explaining the principle of contrast improvement.

[13 (b)] is a diagram for explaining the principle of contrast improvement.

[14 (a)] is a diagram for explaining the principle of contrast improvement.

[14 (b)] is a diagram for explaining the principle of contrast improvement.

[14 (c)] is a diagram for explaining the principle of contrast improvement.

[15 (a)] is a diagram for explaining the principle of contrast improvement. [15 (b)] is a diagram for explaining the principle of contrast improvement.

[16] (a)] is a diagram for explaining the principle of contrast improvement.

[16 (b)] is a diagram for explaining the principle of contrast improvement.

FIG. 17 is a graph showing the relationship between the wavelength and transmittance of each color in the panel of the present invention and the conventional panel.

FIG. 18 is a graph showing the relationship between wavelength and spectral intensity when displaying blue in the panel of the present invention and the conventional panel.

FIG. 19 is a graph showing the entire chromaticity diagram.

20 is an enlarged view of the main part of the chromaticity diagram shown in FIG.

FIG. 21 is a view showing an embodiment of the present invention and showing an example in which a light diffusion layer is arranged in front of a polarizing plate of a first panel.

FIG. 22 is a view showing an embodiment of the present invention and showing an example in which a light diffusion layer is arranged in front of a second panel.

FIG. 23 illustrates an embodiment of the present invention and is a diagram illustrating an example in which a light diffusion layer is disposed between polarizing plates of a first panel and a second panel.

FIG. 24 shows an embodiment of the present invention, and is a diagram showing an example in which a lens sheet as a light diffusion layer is disposed between respective polarizing plates of a first panel and a second panel.

FIG. 25 is a schematic cross-sectional view for explaining the mechanism of moire generation in a two-panel liquid crystal display device.

FIG. 26 is a schematic cross-sectional view of a configuration in which moiré is suppressed in a two-panel liquid crystal display device.

FIG. 27 is a schematic cross-sectional view showing another example of a configuration in which moiré is suppressed in a two-panel liquid crystal display device.

FIG. 28 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 29 is a diagram showing an arrangement relationship between a polarizing plate and a panel in the liquid crystal display device shown in FIG.

30 is a plan view of the vicinity of a pixel electrode of the liquid crystal display device shown in FIG.

FIG. 31 (a) is a diagram showing another example of countermeasures for moire. FIG. 31 (b) is a diagram showing another example of countermeasures for moire.

FIG. 31 (c) is a diagram showing another example of countermeasure against moire.

FIG. 32 is a block diagram of a display controller for realizing the moire countermeasure shown in FIG. 31.

FIG. 33 (a) is a diagram showing another example of countermeasures for moire.

FIG. 33 (b) is a diagram showing another example of countermeasure against moire.

FIG. 33 (c) is a diagram showing another example of countermeasure against moire.

FIG. 34 is a block diagram of a display controller for realizing the moire countermeasure shown in FIG. 33.

FIG. 35 is a graph showing gradation-luminance characteristics.

FIG. 36 is a logarithmic graph of the gradation-one luminance characteristic shown in FIG.

FIG. 37 is a graph showing gradation-luminance characteristics.

FIG. 38 is a logarithmic graph of the gradation-one luminance characteristic shown in FIG.

FIG. 39 is a graph showing gradation-luminance characteristics.

FIG. 40 is a logarithmic graph of the gradation-one luminance characteristic shown in FIG.

FIG. 41 is a schematic block diagram of a television receiver including the liquid crystal display device of the present invention.

42 is a block diagram showing a relationship between a tuner unit and a liquid crystal display device in the television receiver shown in FIG. 41.

FIG. 43 is an exploded perspective view of the television receiver shown in FIG. 41.

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1]

An embodiment of the present invention will be described as follows.

[0060] Before describing a liquid crystal display device that works according to the present embodiment, a configuration of a general liquid crystal display device will be described.

As shown in FIG. 8, a general liquid crystal display device is configured by bonding polarizing plates A and B to a liquid crystal panel including a color filter and a driving substrate. Here, the MVA (Multidom ain Vertical Alignment) method is explained.

As shown in FIG. 9, the polarization axes of the polarizing plates A and B are perpendicular to each other, and the threshold voltage is applied to the pixel electrode 8. When liquid crystal is applied, the direction in which the liquid crystal is tilted and aligned is set to 45 ° with the polarization axis of the polarizing plates A and B. At this time, since the polarization axis rotates when the incident polarized light passing through the polarizing plate A passes through the liquid crystal layer, light is emitted from the polarizing plate B. In addition, when only a voltage lower than the threshold voltage is applied to the pixel electrode, the liquid crystal is aligned perpendicular to the substrate and the deflection angle of incident polarization does not change, resulting in black display. The MVA method achieves a high viewing angle by dividing the direction in which the liquid crystal tilts when a voltage is applied into four (Multidomain).

However, in the case of the two-polarizing plate configuration, there is a limit to the improvement in contrast. Therefore, the inventors of the present application show that the shutter performance is improved in both the front and the diagonal directions by adopting three polarizing plates for each of the two liquid crystal display panels (each installed in a cross-coll). I found it.

[0064] The principle of contrast improvement will be described below.

[0065] Specifically,

(1) Front direction

Cross-col transmission axis direction force leakage light was generated due to depolarization in the panel (scattering of CF, etc.). By using the above three polarizing plates, transmission through the second polarizing plate It was found that the leakage light can be cut by matching the absorption axis of the third polarizing plate with respect to the axial leakage light.

[0066] (2) About diagonal direction

It was found that the change in the amount of leaked light was insensitive to the collapse of the polarizing plate Nicol angle φ, that is, black did not easily float with respect to the spread of the −Col angle φ at an oblique viewing angle.

[0067] From the above, it was found that the contrast is greatly improved in the liquid crystal display device. In the following, the principle of contrast improvement will be described with reference to FIGS. 10 to 16 and Table 1. Here, the description will be made assuming that the two-polarizing plate configuration is the configuration (1) and the three-polarizing plate configuration is the configuration (2). The improvement in the contrast in the oblique direction is essentially caused by the configuration of the polarizing plate. Therefore, the description here is based on the polarizing plate alone, without using the liquid crystal panel.

[0068] FIG. 10 (a) assumes the case where there is one liquid crystal display panel in the configuration (1). FIG. 10 (b) shows an example in which two polarizing plates 101a′101b are arranged in a cross-col, and FIG. 10 (b) shows that in configuration (2), the three polarizing plates 101a′101b′101c are cross-cold with each other. It is a figure which shows the example arrange | positioned at. In other words, since the configuration (2) assumes that there are two liquid crystal display panels, there are two pairs of polarizing plates arranged in a cross-col. FIG. 10 (c) is a diagram showing an example in which the polarizing plates 101a and 101b facing each other are arranged in a cross-col, and polarizing plates having the same polarization direction are superimposed on the outer sides of the respective polarizing plates. In addition, in FIG. 10 (, a pair of polarizing plates in a force cross-col relationship showing the configuration of four polarizing plates is assumed to hold one liquid crystal display panel. .

[0069] The transmittance when the liquid crystal display panel displays black is modeled as the transmittance when the polarizing plate without the liquid crystal panel is arranged in a cross-cor arrangement, that is, the cross transmittance, and is called black display. The transmittance when the display panel displays white is modeled as the black transmittance when the polarizing plate without the liquid crystal panel is arranged in parallel-col, that is, parallel transmittance. Example forces showing the relationship between the wavelength and transmittance of the transmission spectrum when the frontal force is seen on the plate, and the relationship between the wavelength and transmittance of the transmission spectrum when the polarizing plate is seen obliquely Fig. 11 (a) to Fig. 11 ( It is a graph shown in d). The modeled transmittance corresponds to an ideal value of transmittance for white display and black display in a method in which a polarizing plate is arranged in a crossed Nicol manner and a liquid crystal panel is held.

[0070] Fig. 11 (a) is a graph when the relationship between the wavelength of the transmission spectrum and the cross transmittance when the polarizing plate is viewed from the front is compared between the configuration (1) and the configuration (2). is there. From this graph, it can be seen that the transmittance characteristics in the front of the black display tend to be similar to configurations (1) and (2).

[0071] FIG. 11 (b) is a graph in the case where the relationship between the wavelength of the transmission spectrum and the parallel transmittance when the frontal force of the polarizing plate is viewed is compared between the configuration (1) and the configuration (2). . From this graph, it can be seen that the transmittance characteristics in the front of the white display tend to be similar to configurations (1) and (2).

[0072] Figure 11 (c) shows the relationship between the wavelength of the transmission spectrum and the cross transmittance when the polarizing plate is tilted (azimuth angle 45 °-polar angle 60 °). It is a graph when comparing with the configuration (2). From this graph, the transmittance characteristics in the diagonal of black display are mostly in the configuration (2). It can be seen that the transmissivity is almost 0 in any wavelength range, and in the configuration (1), a slight amount of light can be seen in most wavelength ranges. In other words, it can be seen that light leakage occurs at an oblique viewing angle when black is displayed (a worsening of black tightening) in the two-polarizing plate configuration, and conversely, an oblique viewing angle is displayed when black is displayed in the three-polarizing plate configuration. It can be seen that light leakage (deterioration of black tightening) is suppressed.

[0073] Figure 11 (d) shows the relationship between the wavelength of the transmission spectrum and the parallel transmittance when the polarizing plate is tilted (azimuth angle 45 °-polar angle 60 °). It is a graph when comparing with the configuration (2). From this graph power, it can be seen that the transmittance characteristics of the white display in the oblique direction tend to be similar between the configuration (1) and the configuration (2).

[0074] From the above, at the time of white display, as shown in Fig. 11 (b) and Fig. 11 (d), the difference depending on the number of polarizing plates, that is, the number of -colcross pairs of polarizing plates is almost in front. It can be seen that the transmittance characteristics are almost the same regardless of whether it is diagonal or oblique.

[0075] However, when black is displayed, as shown in Fig. 11 (c), in the case of the configuration (1) in which the cross-col pair is 1, there is a black tightening error at an oblique viewing angle. As a result, in the case of the configuration (2) in which the cross-col pair is 2, it is understood that the black tightening at the oblique viewing angle is suppressed.

[0076] For example, when the wavelength of the transmission spectrum is 550 nm, the relationship between the transmittance when viewed from the front and oblique directions is as shown in Table 1 below.

[0077] [Table 1]

550nm

Here, in Table 1, “parallel” indicates parallel transmittance, and indicates transmittance when white is displayed. Further, the cross indicates a cross transmittance, and indicates a transmittance during black display. Therefore, Parallel / Cross indicates contrast.

[0079] From Table 1, the front contrast in configuration (2) is approximately twice that in configuration (1), and the diagonal contrast in configuration (2) is approximately 22 times that in configuration (1). And the diagonal contra It can be seen that the strike is greatly improved.

[0080] The viewing angle characteristics during white display and black display will be described below with reference to FIGS. 12 (a) to 12 (c). Here, the case where the azimuth angle with respect to the polarizing plate is 45 ° and the wavelength of the transmission spectrum is 550 nm will be described.

FIG. 12 (a) is a graph showing the relationship between the polar angle and the transmittance during white display. From this graph, the transmittance of the configuration (2) is generally lower than that of the configuration (1). In this case, the viewing angle characteristics (parallel viewing angle characteristics) are the same as those of the configuration (2). It can be said that the structure (1) has a similar tendency.

FIG. 12B is a graph showing the relationship between polar angle and transmittance during black display. It can be seen that in the case of configuration (2), this graph power suppresses transmittance at an oblique viewing angle (around polar angle ± 80 °). Conversely, in the case of the configuration (1), it can be seen that the transmittance at an oblique viewing angle is increased. In other words, the configuration (1) is more prominent in black tightening at an oblique viewing angle than the configuration (2).

[0083] FIG. 12 (c) is a graph showing the relationship between polar angle and contrast. From this graph, the configuration

It can be seen that the contrast in (2) is much better than in the case of configuration (1)! The reason why the vicinity of 0 ° in configuration 2 in Fig. 12 (c) is flat is that the black transmittance is so small that it cannot be calculated and the calculation is smooth.

[0084] Next, the change in the amount of leakage light is insensitive to the collapse of the polarizing plate Nicol angle φ, that is, the black tightening is less likely to occur with respect to the spread of the −Col angle φ at an oblique viewing angle. This will be described below with reference to FIGS. 13 (a) and 13 (b). Here, as shown in FIG. 13 (a), the polarizing plate-col angle φ means an angle in a state in which the polarization axes of the polarizing plates facing each other are in a twisted relationship. Fig. 13 (a) is a perspective view of a polarizing plate in which crossed Nicols are arranged, and the Nicol angle φ changes by 90 ° (corresponding to the collapse of the -Col angle).

FIG. 13 (b) is a graph showing the relationship between the Nicol angle φ and the cross transmittance. Calculate using the ideal polarizer (parallel-col transmittance 50%, cross-col transmittance 0%). From this graph, it can be seen that the degree of change in the transmittance with respect to the change in the Nicol angle φ is smaller in the configuration (2) than in the configuration (1) during black display. In other words, the three-polarizer configuration is less susceptible to changes in the -col angle Φ than the two-polarizer configuration. Karu.

Next, the thickness dependency of the polarizing plate will be described below with reference to FIGS. 14 (a) to 14 (c). Here, as shown in Fig. 10 (c), the thickness of the polarizing plate is adjusted by superposing polarizing plates with the same polarization axis one by one on a pair of polarizing plates arranged in crossed Nicols (3 ). FIG. 10 (c) shows an example in which polarizing plates 101a and 101b having the same polarization direction are superimposed on each of a pair of cross-cold polarizing plates 101a and 101b. . In this case, since the polarizing plate is provided with two polarizing plates in addition to two polarizing plates arranged in a pair of cross-colls, the cross is one-on-one. Similarly, if the number of polarizing plates to be superimposed increases, it is assumed that the cross pair is −3, −4,.

FIG. 14 (a) is a graph showing the relationship between the polarizing plate thickness and the transmittance (cross transmittance) of a pair of cross-col arranged polarizing plates during black display! . For comparison, this graph shows the transmittance in the case of having two pairs of cross-cold polarizing plates.

[0088] FIG. 14 (b) is a graph showing the relationship between the thickness of the polarizing plates arranged in a pair of cross-cols and the transmittance (parallel transmittance) during white display. For comparison, this graph shows the transmittance in the case of having two pairs of cross-cold polarizing plates.

[0089] From the graph shown in Fig. 14 (a), it can be seen that if the polarizing plates are overlapped, the transmittance during black display can be reduced, but the polarizing plate is overlapped from the graph shown in Fig. 14 (b). When combined, it can be seen that the transmittance during white display is reduced. In other words, in order to suppress the deterioration of black tightening at the time of black display, the transmittance at the time of white display is lowered only by overlapping the polarizing plates.

[0090] Further, a graph showing the relationship between the thickness of a polarizing plate arranged in a pair of cross-cols and contrast is as shown in FIG. 14 (c). For comparison, this graph shows the contrast in the case of having two pairs of crossed Nicol polarizing plates.

[0091] As described above, from the graphs shown in FIGS. 14 (a) to 14 (c), the configuration of the polarizing plates arranged in two pairs of cross-cols shows that the black tightening at the time of black display is poor. It can be seen that the transmittance can be suppressed and the decrease in transmittance during white display can be prevented. Moreover, two pairs of cross-cold polarizing plates Since it consists of three polarizing plates in total, it can be seen that the thickness of the entire liquid crystal display device can be increased and the contrast can be greatly improved.

[0092] Figs. 15 (a) and 15 (b) specifically show the viewing angle characteristics of the cross-col transmittance. FIG. 15 (a) is a diagram showing the crossed-coll pair of polarizing plates in the configuration (1), that is, the cross-coll viewing angle characteristics, and FIG. 15 (b) is the diagram of the configuration (2). FIG. 5 is a diagram showing the cross-col viewing angle characteristics of a case where three crossed Nicols two pairs of polarizing plates are used.

[0093] From the diagrams shown in Figs. 15 (a) and 15 (b), in the cross-col two-pair configuration, there is almost no deterioration in black tightening (corresponding to an increase in transmittance during black display). You can see (especially 45 °, 135 °, 225 °, 315 ° directions).

[0094] Further, FIGS. 16 (a) and 16 (b) specifically show the contrast viewing angle characteristics (parallel Z cross luminance). FIG. 16 (a) is a diagram showing the contrast viewing angle characteristics of the configuration (1), that is, the configuration of two cross-coll pair polarizers, and FIG. 16 (b) shows the field of the configuration (2). In other words, it is a diagram showing the contrast viewing angle characteristics of the three cross-col pair polarizing plate configuration.

[0095] From the diagrams shown in FIGS. 16 (a) and 16 (b), it can be seen that the contrast of the cross-col pair configuration is improved compared to the cross-col pair configuration.

Here, an embodiment for improving the color reproduction range of the liquid crystal display device using the above-described principle of improving contrast will be described below with reference to FIGS.

FIG. 1 is a diagram showing a schematic cross section of a liquid crystal display device 100 according to the present embodiment.

As shown in FIG. 1, the liquid crystal display device 100 is configured by alternately bonding a first panel, a second panel, and polarizing plates A, B, and C.

FIG. 2 is a diagram showing the arrangement of the polarizing plate and the liquid crystal panel in the liquid crystal display device 100 shown in FIG. In FIG. 2, polarizing plates A and B and polarizing plates B and C are configured with their polarization axes perpendicular to each other. That is, polarizing plates A and B and polarizing plates B and C are arranged in a cross-coll.

[0100] Each of the first panel and the second panel encloses a liquid crystal between a pair of transparent substrates (color filter substrate 20 and active matrix substrate 30), and electrically changes the alignment of the liquid crystal. Rotates the polarized light incident on polarizing plate A by approximately 90 degrees. And means for arbitrarily changing the state in which the polarization is not rotated and the intermediate state thereof.

[0101] Each of the first panel and the second panel includes a color filter (CF) and has a function of displaying an image with a plurality of pixels. Display methods with such functions include TN (Twisted Nematic) method, VA (Vertical Alignment) method, IPS (In Plain Switching) method, FFS method (Fringe Field Switching) method or a combination of these methods. However, the VA method with high contrast is suitable even when used alone. Here, the force IPS method and FFS method that are explained using the MVA (Multidomain Vertical Alignment) method are also normally black methods, so there is a sufficient effect. . The drive system uses active matrix drive by TFT (Thin Film Transistor). MVA manufacturing

The details are disclosed in Japanese Patent Publication (Japanese Patent Laid-Open No. 2001-83523).

[0102] The first and second panels in the liquid crystal display device 100 have the same structure, and have the color filter substrate 20 and the active matrix substrate 30 facing each other, as described above, In addition, a columnar resin structure provided on the color filter substrate 20 or the like is used as a spacer (not shown) to keep the substrate interval constant. Liquid crystal is sealed between a pair of substrates (color filter substrate 20 and active matrix substrate 30), and a vertical alignment film 25 is formed on the surface of each substrate in contact with the liquid crystal. As the liquid crystal, a nematic liquid crystal having a negative dielectric anisotropy is used.

[0103] The color filter substrate 20 is obtained by forming the color filter 21, the black matrix (BM) 24, and the like on the transparent substrate 10.

As shown in FIG. 1, the active matrix substrate 30 has a TFT element 3, a pixel electrode 8, etc. formed on a transparent substrate 10, and further, alignment control protrusions 22 that define the alignment direction of the liquid crystal and It has a slit pattern 11 (see Fig. 3). When a voltage equal to or higher than the threshold value is applied to the pixel electrode 8, the liquid crystal molecules are tilted in a direction perpendicular to the protrusions 22 and the slit pattern 11. In the present embodiment, as shown in FIG. 3, the protrusion 22 and the slit pattern 11 are formed so that the liquid crystal is aligned in the direction of an azimuth angle of 45 degrees with respect to the polarization axis of the polarizing plate. Here, FIG. 3 is a diagram in which the black matrix 24 of the color filter substrate 20 is virtually superimposed on the TFT element 3 on the active matrix substrate 30, and the black matrix 24 is connected to the TFT. It is not a figure showing a state (BMonTFT) installed directly on element 3.

[0105] As described above, the first panel and the second panel correspond to the red color of each color filter 21.

The (R) green (G) blue (B) pixels are configured such that their positions when viewed from the vertical direction match each other. Specifically, the R pixel on the first panel is the R pixel on the second panel, the G pixel on the first panel is the G pixel on the second panel, and the B pixel on the first panel is The position viewed from the vertical direction coincides with the B pixel of the second panel.

FIG. 4 shows an outline of a drive system of the liquid crystal display device 100 having the above configuration.

The drive system has a display controller necessary for displaying an image on the liquid crystal display device 100.

[0108] The display controller includes first and second panel drive circuits (1) and (2) for driving the first panel and the second panel with predetermined signals, respectively. Furthermore, the first and second panel drive circuits (1) and (2) have a signal distribution circuit section for distributing video source signals.

Accordingly, the display controller sends a signal to each panel so that an appropriate image can be displayed on the liquid crystal display device 100.

[0110] The display controller is a device for sending an appropriate electrical signal to a given video signal power panel, and includes a driver, a circuit board, a panel drive circuit, and the like.

[0111] FIG. 5 shows the connection relationship between the first and second panels and the respective panel drive circuits. In FIG. 5, the polarizing plate is omitted.

The first panel drive circuit (1) is connected to a terminal (1) provided on the circuit board (1) of the first panel via a driver (TCP) (1). In other words, a dry (TCP) (1) is connected to the first panel, connected by the circuit board (1), and connected to the panel drive circuit (1).

[0113] Note that the connection of the second panel drive circuit (2) in the second panel is also the same as that in the first panel, and a description thereof will be omitted.

Next, the operation of the liquid crystal display device 100 having the above configuration will be described.

[0115] The pixels of the first panel are driven based on a display signal, and the corresponding pixels of the second panel corresponding to the positions of the pixels of the first panel and the positions viewed from the vertical direction of the panel are Driven corresponding to the first panel. Consists of polarizing plate A, first panel and polarizing plate B When the part (component 1) is in the transmissive state, the part formed by the polarizing plate B, the second panel, and the polarizing plate C (component 2) is also in the transmissive state, and when the part 1 is in the non-transmissive state Component 2 is also driven to be non-transmissive.

[0116] The same image signal may be input to the first and second panels, or different signals linked to each other may be input to the first and second panels.

Here, a manufacturing method of the active matrix substrate 30 and the color filter substrate 20 will be described.

First, a method for manufacturing the active matrix substrate 30 will be described.

First, as shown in FIG. 3, a Ti / Al / Ti laminated film is formed on the transparent substrate 10 by sputtering in order to form the scanning signal wiring (gate wiring or gate bus line) 1 and the auxiliary capacitance wiring 2. A metal such as a film is formed, a resist pattern is formed by a photolithography method, dry etching is performed using an etching gas such as a chlorine-based gas, and the resist is peeled off. As a result, the scanning signal wiring 1 and the auxiliary capacitance wiring 2 are simultaneously formed on the transparent substrate 10.

[0120] Thereafter, a gate insulating film such as silicon nitride (SiNx), an active semiconductor layer made of amorphous silicon, or the like, an amorphous silicon doped with phosphorus or the like, and a low resistance semiconductor layer also made of amorphous silicon or the like are formed by CVD. , Data signal wiring (source wiring or source nose line) 4, drain lead wiring 5, auxiliary capacitance forming electrode 6 A metal such as AlZTi is formed by sputtering, and a resist pattern is formed by photolithography. The resist is removed by dry etching using an etching gas such as a chlorine-based gas. As a result, the data signal wiring 4, the drain lead wiring 5, and the auxiliary capacitance forming electrode 6 are formed simultaneously.

Note that the auxiliary capacitance is formed by sandwiching a gate insulating film of about 4000 A between the auxiliary capacitance wiring 2 and the auxiliary capacitance forming electrode 6.

[0122] Thereafter, the TFT element 3 is formed by dry etching the low-resistance semiconductor layer using chlorine gas or the like for source / drain separation.

[0123] Next, an interlayer insulating film 7 having a strength such as an acrylic photosensitive resin is applied by spin coating, and a contact hole for electrically contacting the drain lead wiring 5 and the pixel electrode 8 9 is formed by a photolithography method. The film thickness of the interlayer insulating film 7 is about 3 m.

[0124] Further, the pixel electrode 8 and the vertical alignment film (not shown) are formed in this order.

Note that the present embodiment is an MVA type liquid crystal display device as described above, and the slit pattern 11 is provided in the pixel electrode 8 made of ITO or the like. Specifically, a film is formed by sputtering, a resist pattern is formed by a photolithography method, etching is performed with an etching solution such as a mixed solution of ferric chloride and hydrochloric acid, and a pixel electrode pattern as shown in FIG. 3 is formed. obtain.

[0126] The active matrix substrate 30 is obtained as described above.

In addition, FIG. 3 [reference numerals 12a, 12b, 12c, 12d, 12e, 12fi shown in FIG. At the electrical connection part in this slit, the orientation is disturbed and an orientation abnormality occurs. However, in the slits 12a to 12d, in addition to the alignment abnormality, the voltage supplied to the gate wiring is normally applied to the positive potential supplied to operate the TFT element 3 in the ON state, which is usually in the order of seconds. The time during which the minus potential supplied to operate the TFT element 3 in the off state is normally on the order of milliseconds, so the time during which the minus potential is applied is dominant. For this reason, when the slits 12a to 12d are positioned on the gate wiring, impurity ions contained in the liquid crystal gather due to the gate minus DC application component, and may be visually recognized as display unevenness. Therefore, since the slits 12a to 12d need to be provided in a region that does not overlap with the gate wiring in a plan view, it is preferable to hide the slits 12a to 12d with the black matrix 24 as shown in FIG.

[0128] Next, a method for manufacturing the color filter substrate 20 will be described.

[0129] The color filter substrate 20 is formed on the transparent substrate 10 with a color filter layer 21 made of three primary colors (red, green, blue) 21 and a black matrix (BM) 24, a counter electrode 23, a vertical alignment film, and the like. 25 and a protrusion 22 for controlling the orientation.

First, a negative acrylic photosensitive resin solution in which carbon fine particles are dispersed is applied onto the transparent substrate 10 by spin coating, and then dried to form a black photosensitive resin layer. Subsequently, after the black photosensitive resin layer is exposed through a photomask, development is performed to form a black matrix (BM) 24. At this time, the first colored layer (for example, red layer), the second colored layer ( For example, an opening for the first colored layer, an opening for the second colored layer, and an opening for the third colored layer in the regions where the third colored layer (for example, the blue layer) is formed (for example, the green layer) BM is formed so that each opening corresponds to each pixel electrode). More specifically, as shown in FIG. 3, the BM pattern is formed in an island shape to shield the alignment abnormal region generated in the slits 12a to 12d of the electrically connected portions of the slits 12a to 12f formed in the pixel electrode 8. In addition, a light shielding portion (BM) is formed on the TFT element 3 in order to prevent an increase in leakage current that is photoexcited by external light entering the TFT element 3.

Next, after applying a negative acrylic photosensitive resin solution in which a pigment is dispersed by spin coating, drying is performed, and exposure and development are performed using a photomask to form a red layer.

[0132] Thereafter, the second color layer (for example, the green layer) and the third color layer (for example, the blue layer) are similarly formed, and the color filter 21 is completed.

[0133] Further, a counter electrode 23 having a transparent electrode force such as ITO is formed by sputtering, and then a positive type phenol novolac photosensitive resin solution is applied by spin coating, followed by drying and a photomask. Are used for exposure and development to form vertical alignment control protrusions 22.

As described above, the color filter substrate 20 is formed.

In this embodiment, the chromaticity and N TSC ratio in the CIE1931 chromaticity diagram when the liquid crystal panel is used are shown in Table 2 as red (R), green (G), and blue (B). A color filter having a colored layer was used. The film thickness of each color filter is 1.7 m, and the film thickness of BM is 1.3 m. Table 2 will be described later.

[0136] Further, in the present embodiment, a BM made of a force metal as shown in the case of a BM made of resin may be used. The three primary color layers may include cyan, magenta, yellow, and other white layers as well as red, green, and blue, and may include a white layer.

A method of manufacturing a liquid crystal panel (first panel, second panel) using the color filter substrate 20 and the active matrix substrate 30 manufactured as described above will be described below.

First, the vertical alignment film 25 is formed on the surface of the color filter substrate 20 and the active matrix substrate 30 in contact with the liquid crystal. Specifically, baking is performed as a degassing process before alignment film application, and then substrate cleaning and alignment film application are performed. After applying the alignment film, firing the alignment film Do. After the alignment film is applied and washed, further baking is performed as a degassing process. The vertical alignment film 25 defines the alignment direction of the liquid crystal 26.

[0139] Next, a method of sealing liquid crystal between the active matrix substrate 30 and the color filter substrate 20 will be described.

[0140] With respect to the method of sealing the liquid crystal, for example, an injection port is provided for injecting a part of the thermosetting seal resin around the substrate, and the injection port is immersed in liquid crystal in a vacuum and opened to the atmosphere. It may be performed by a method such as a vacuum injection method in which liquid crystal is injected and then the injection port is sealed with UV curing resin or the like. However, the vertical alignment liquid crystal panel has a drawback that the injection time is much longer than that of the horizontal alignment panel. Here, explanation is given by the liquid crystal drop bonding method.

[0141] A UV curable sealant is applied around the active matrix substrate side, and the liquid crystal is dropped onto the color filter substrate by the dropping method. The optimal amount of liquid crystal is regularly dropped on the inner part of the seal so that the desired cell gap is achieved by liquid crystal by the liquid crystal dropping method.

[0142] Furthermore, in order to bond the color filter substrate on which seal drawing and liquid crystal dropping as described above and the active matrix substrate are bonded, the atmosphere in the bonding apparatus is reduced to lPa. After bonding, the seal portion is crushed by setting the atmosphere to atmospheric pressure, and the desired gap of the seal portion is obtained.

[0143] Next, the structure having a desired cell gap in the seal portion is subjected to UV irradiation with a UV curing device to temporarily cure the seal resin. In addition, beta is performed to final cure the seal resin. At this point, the liquid crystal spreads inside the seal resin and the liquid crystal is filled in the cell. The liquid crystal panel is completed by dividing the structure into liquid crystal panel units after the beta is completed.

In the present embodiment, the first panel and the second panel are manufactured by the same process.

[0145] Next, a mounting method of the first panel and the second panel manufactured by the above-described manufacturing method will be described.

Here, after the first panel and the second panel are washed, a polarizing plate is attached to each panel. Specifically, as shown in FIG. 4, polarizing plates A and B are attached to the front and back surfaces of the first panel, respectively. Also attach polarizing plate C to the back of the second panel. wear. In addition, you may laminate | stack an optical compensation sheet etc. on a polarizing plate as needed.

Next, a driver (LCD driving LSI) is connected. Here, the driver will be described using a TCP (Tape Carrier Package) connection.

[0148] For example, as shown in FIG. 5, after ACF (Arisotoropi Conductive Film) is temporarily pressure-bonded to the terminal portion (1) of the first panel, TCP (1) on which the driver is placed is driven from the carrier tape. Pull out, align with the panel terminal electrode, heat and crimp. After that, the circuit board (1) for connecting the drivers TCP (1) and the input terminal (1) of TCP (l) are connected by ACF.

[0149] Next, the two panels are bonded together. Polarizing plate B has an adhesive layer on both sides. Clean the surface of the second panel, peel off the laminate of the adhesive layer of Polarizer B attached to the first panel, align precisely, and bond the first panel and the second panel together. At this time, since bubbles may remain between the panel and the adhesive layer, it is desirable to bond them together under vacuum.

[0150] As another bonding method, an adhesive that cures at room temperature or below the heat resistance temperature of the panel, such as an epoxy adhesive, is applied to the periphery of the panel, and a plastic spacer is sprayed. Oil or the like may be enclosed. A liquid that is optically isotropic, has a refractive index similar to that of a glass substrate, and is as stable as liquid crystal is desirable.

[0151] The present embodiment can also be applied to the case where the terminal surface of the first panel and the terminal surface of the second panel are at the same position, as shown in Figs. 4 and 5. . Also, there are no particular restrictions on the direction of terminals and the method of bonding to the panel. For example, a mechanical fixing method may be used regardless of adhesion.

[0152] Thereafter, the liquid crystal display device 100 is obtained by integrating with an illumination device called a backlight.

[0153] Here, a specific example of a lighting device suitable for the present invention will be described below. However, this invention is not restricted to the form of the illuminating device given below, It can change suitably.

[0154] The liquid crystal display device 100 of the present invention is required to have a backlight capable of providing a larger amount of light than a conventional panel according to the display principle. Figure 6 shows an example of a lighting device that satisfies these conditions. In the liquid crystal display device 100 according to the present invention, a hot cathode lamp is used this time in order to obtain the same luminance as the conventional one. Hot cathode lamps are characterized by being able to output approximately six times the amount of light than cold cathode lamps used in general specifications.

[0156] Taking a 37-inch diagonal WXGA as an example of a standard liquid crystal display device, 18 lamps with an outer diameter of 15 mm are placed on a housing made of aluminum. In order to efficiently use the light emitted in the rear direction of the lamp force, this housing is provided with a white reflective sheet using foamed resin. A driving power source for the lamp is disposed on the rear surface of the housing, and the lamp is driven by electric power supplied from a household power source.

[0157] Next, in order to extinguish the lamp image in the direct type backlight in which a plurality of lamps are arranged in this nodding, a milky white resin board is required. This time, a plate member based on polycarbonate, which is 2 mm thick and absorbs warp and heat deformation, is placed in the housing on the lamp, and the optical sheet to obtain the predetermined optical effect on its upper surface, specifically this time In the bottom, a diffusion sheet, a lens sheet, a lens sheet, and a polarized light reflection sheet are arranged. This specification makes it possible to obtain a backlight brightness that is about 10 times that of the general specifications of 18 cold-cathode lamps with a diameter of 4 mm, two diffuser sheets, and a polarizing reflection sheet. Thereby, the liquid crystal display device of the present onset Ming 37 inch (37-), it is possible to obtain a luminance of about 400cdZm ^2.

[0158] However, since the amount of heat generated by this backlight is five times that of the conventional one, fins that radiate heat to the air and fans that force the air flow are installed on the back of the back chassis.

[0159] The mechanism member of the present lighting device serves as the main mechanism member of the entire module, and the liquid crystal display controller including the panel mounted circuit and the signal distributor, wherein the mounted panel is disposed in the backlight. A liquid crystal module is completed by installing a power source for the light source and, in some cases, a general household power source. The mounted panel is disposed in the backlight, and a frame body that holds the panel is installed to provide the liquid crystal display device of the present invention.

In this embodiment, as described in Table 2, a backlight light source having a red dominant wavelength of 611 nm, a green dominant wavelength of 540 ηm, and a blue dominant wavelength of 450 nm was used. In Table 2, a panel with only one color filter is a conventional panel, and a panel with two color filters is A light panel. In Table 3 below, the definitions of the conventional panel and the present invention panel are the same as in Table 2.

[0161] [Table 2]

[0162] Note that in this embodiment, a direct-type illumination device using a hot cathode tube is shown, but depending on the application, a light source that may be a projection method or an edge light method is a cold cathode tube or an LED, It is possible to appropriately select a combination of optical sheets and the like using O EL, electron beam fluorescent tubes, and the like.

[0163] From Table 2, the NTSC ratio was 74.5% for the conventional panel (panel with only one color filter), but the panel of the present invention (panel with two color filters) Shows a color reproduction range of 92%.

Here, FIG. 17 shows a graph of the transmission characteristics of the panel of the present invention panel and the conventional panel. From the graph shown in FIG. 17, it can be seen that the panel of the present invention has a steeper transmittance of the green emission spectrum than the conventional panel. As a result, the green light emission spectrum has a sharp transmittance and the green light emission spectrum eliminates color mixing due to an increase in the number of regions that overlap the blue light emission spectrum transmission region, thereby improving the color reproduction range. It turns out that it is possible.

[0165] As described above, in order to improve the color reproduction range, it is necessary to make the absorption spectrum of the color filter steep. In order to realize a color filter in one layer, it is necessary to increase the pigment concentration by increasing the film thickness of the color filter or increasing the pigment concentration without increasing the film thickness. However, increasing the film thickness of the color filter makes it difficult to control the pattern edge portion of the color filter. Do bad at the edge. Similarly, when the pigment concentration is increased, it becomes difficult to control the pattern edge portion. Therefore, it has been difficult to further improve the color reproduction range with a single color filter layer.

However, in the liquid crystal display device of the present invention, since two or more liquid crystal panels are stacked, a plurality of color filters can be provided in two or more layers. As a result, the above-described problems can be solved. The absorption spectrum of the color filter can be made steep.

[0167] Here, the color reproduction range can be further improved by adjusting the emission spectrum of the knock light source. The liquid crystal display device of the present invention has a particularly preferable configuration.

[0168] Specifically, the main wavelength peak of each color of the knocklight light source is as shown in Table 3 below. That is, the red dominant wavelength is moved to the long wavelength side (611 nm → 658 nm), the green dominant wavelength is moved to the short wavelength side (540 nm → 516 nm), and the blue dominant wavelength is moved to the short wavelength side (450 nm → 447 nm).

[0169] [Table 3]

Here, the backlight light source set to the wavelength shown in Table 3 is referred to as a high color purity phosphor (high color phosphor). Further, the backlight source set to the wavelength shown in Table 2 is referred to as a conventional phosphor. Moreover, as a backlight light source satisfying the above wavelength, for example, there is a phosphor whose composition is BaMgAl 2 O 3.

0 17

FIG. 18 is a graph showing spectral intensity data when blue display is performed in the conventional panel and the panel of the present invention when the conventional phosphor and the high-color phosphor are used, respectively. FIG. 19 shows a color reproduction range diagram of the CIE1931 colorimeter, and FIG. 20 shows an enlarged blue region in the color reproduction range diagram shown in FIG.

[0172] For example, as shown in Table 3, when a backlight source made of a high-color phosphor is applied to Fig. 8, which is a general liquid crystal display device (conventional panel), from Table 3, the NTSC ratio is 91 5% However, as shown in Fig. 18, since the green emission spectrum distribution affects the transmission region in the absorption spectrum distribution of the blue color filter, the blue color is green as shown in Figs. 19 and 20. It ’s going to happen.

On the other hand, when the present invention is applied to, for example, the liquid crystal display device (present invention panel) shown in FIG. 1, the blue color can be improved as shown in FIG. 19 and FIG. The NTSC ratio can be 119.6%.

Here, as the phosphors of the respective colors of the knocklight light source, those shown in Table 4 below can be used.

[0175] [Table 4]

[0176] The principal wavelength of each color can be appropriately adjusted by those skilled in the art by variously selecting commercially available phosphor materials from Nichia Corporation and Kasei Optonitas.

[0177] For example, in the case of a fluorescent material manufactured by Nichia Corporation, those shown in Tables 5 to 13 below are suitable as the fluorescent material of the present application.

[0178] [Table 5] LAMP PHOSPHORS (Halo Phosphate)

[0179] [Table 6]

LAMP PHOSPHORS (Halo Phosphate)

[0180] [Table 7]

LAMP PHOSPHORS (for Tri-color Lamps & Cold Cathode Fluorescent Lamps)

[0181] [Table 8]

AMP PHOSPHORS (Blue)

[0182] [Table 9]

LAMP PHOSPHORS (Blue-green)

* Not available from NICHiAfJust listed for reference)

[0183] [Table 10]

LAMP PHOSPHORS (Green)

[0184] [Table 11]

LAMP PHOSPHORS (Red)

[0185] [Table 12]

[0186] [Table 13]

LAMP PHOSPHORS (Special Application)

[0187] In order to improve the color reproduction range, the peak of the red dominant wavelength is on the long wavelength side, the peak of the green dominant wavelength is on the short wavelength side, and the peak of the blue dominant wavelength is on the short wavelength side. This should be shifted, as is clear from Tables 2 and 3.

[0188] In this case, it is only necessary that the peak of the red dominant wavelength is set within the range of visible light on the long wavelength side. The peak of the blue dominant wavelength is also within the range of visible light on the short wavelength side. The peak of the green dominant wavelength is 505ηπ! It is preferably in the range of ˜540 nm.

[0189] This is also evident from the chromaticity diagram described in, for example, the “New Color Science Handbook (2nd edition)” edited by the Japan Society of Color Science, where a green peak is set on the short wavelength side exceeding 505 nm. If this occurs, color mixing with blue will occur, and if a green peak is set on the long wavelength side exceeding 540 nm, color mixing with red will occur, so an improvement in the color reproduction range cannot be expected.

[0190] Further, in order to improve the color reproduction range, the green peak may be set to 520 nm.

[0191] As described above, the knock light source may be any light source that can adjust the dominant wavelength of each color as appropriate.

[0192] As described above, as a light source capable of appropriately adjusting the main wavelength of the peak of each color, an LED as shown in Table 14 below may be used instead of the phosphor material described above. For example, InGaN is conceivable as a chip material for the LED. Here, InGaN has a continuous peak position from the emission peak in the blue region by a method such as doping impurities. Can be shifted to a long wavelength of 525 nm or more in the green region. This allows continuous peak wavelength selection.

[0193] [Table 14]

[0194] Furthermore, as another embodiment, as a method for controlling the alignment direction of vertically aligned liquid crystal molecules of the liquid crystal, in the embodiment described above, a slit is provided on the pixel electrode of the active matrix substrate and the color filter substrate side. Protrusions for orientation control are provided, but they may be reversed. In addition, a structure in which slits are provided on the electrodes on both substrates, and an MVA type with orientation control projections on the electrode surfaces of both substrates It may be a liquid crystal panel.

[0195] In addition, a method using vertical alignment films in which pretilt directions (alignment treatment directions) defined by a pair of alignment films other than the MVA type are orthogonal to each other may be used. Also, it may be called VATN (Vertical Alibnment Twisted Nematic) mode, which may be VA mode in which the liquid crystal molecules are twisted. The VATN method is more preferable for the present invention because there is no decrease in contrast due to light leakage at the alignment control protrusion. The pretilt is formed by optical alignment or the like.

[0196] Here, a specific example of a driving method in the display controller of the liquid crystal display device 100 having the above configuration will be described with reference to FIG. Here, the case of input 8bit (256 gradations) and liquid crystal driver 8bit is explained.

[0197] In the panel drive circuit (1) of the display controller unit, the input signal (video source) is subjected to drive signal processing such as 0 conversion and overshoot, and the first panel source driver (source drive means) Output 8-bit gradation data. On the other hand, the panel drive circuit (2) performs signal processing such as γ conversion and overshoot, and outputs 8-bit gradation data to the source driver (source drive means) of the second panel. The first panel, the second panel, and the output image that is output as a result are 8 bits, correspond one-to-one with the input signal, and are faithful to the input image.

[0199] As described above, when the first panel and the second panel are overlaid, depending on the resolution of the panel, moire caused by pixel misalignment that occurs when the two panels are overlaid. May occur. In addition, because glass is thick, the light transmitted through the color filters of the two panels may cause color mixing due to parallax and moiré.

[0200] In the present invention, in the following embodiments, the moire reduction when two panels are overlapped will be described.

[0201] [Embodiment 2]

Another embodiment of the present invention will be described as follows. Note that members having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

[0202] In this embodiment, description will be given of reducing the generation of moire by providing a light diffusion layer in liquid crystal display device 100.

[0203] As described above, since the light diffusion layer is provided in the liquid crystal display device 100, the light transmitted through the light diffusion layer can be spatially blurred. As a result, for example, it is possible to suppress the strength of asynchronous interference between fine structures (bus lines, black matrix, alignment control protrusions, etc.) having the same period of adjacent panels. As a result, it is possible to suppress the occurrence of moiré due to structural interference, and thus it is possible to prevent display quality from being deteriorated due to the occurrence of moiré.

[0204] Specifically, a case where a light diffusion layer is arranged will be described.

[0205] As the arrangement position of the light diffusion layer, for example, as shown in FIG. 21, a light diffusion layer may be provided on the outer side of the polarizing plate A, or as shown in FIG. A light diffusing layer may be provided between the polarizing plate B and the polarizing plate B. Most preferably, however, a polarizing plate D is further disposed between the second panel and the polarizing plate B as shown in FIG. A light diffusing layer is provided between the polarizing plate D and the polarizing plate B. Polarizing plate D and polarizing plate B were arranged in parallel coll. [0206] The light diffusing layer includes an acrylic cured resin layer, a TAC (triacetylcellulose) film, a PET (polyethylene terephthalate) film, and other substrates, silica beads, aluminum oxide, and titanium oxide. Use a mixture of transparent particles such as

[0207] As the light diffusion layer, a transparent layer having a rough surface may be used. In this case, the structure of the portion in contact with the air layer as shown in FIG. 21 can provide a reliable light diffusion effect while being inexpensive.

[0208] In the light diffusion layer, diffusion particles having a refractive index different from that of the substrate having an average particle diameter of 370 nm or more may be dispersed and contained. In this case, light with a wavelength of around 555 nm, which is the most visible and dominant as visible light, is 555 ÷ 1.5 = wavelength 370 ηm among the members with a refractive index of 1.5. It can be scattered by refraction.

[0209] In the light diffusion layer, diffusion particles having a refractive index different from that of the substrate having an average particle diameter of 520 nm or more may be dispersed and contained. In this case, the light having the longest wavelength of visible light of 780 nm is 780 + 1.5 = wavelength of 520 nm among the members having a refractive index of 1.5, and the entire visible light region is scattered by refraction. be able to.

[0210] The light diffusion layer may contain dispersed particles having a refractive index different from that of the base material having an average particle diameter of 3.7 μm or more. In this case, by increasing the order of the average particle size by an order of magnitude larger than the visible light scattering condition, stable scattering can be realized by the refractive action that makes the entire visible light region different depending on the wavelength.

[0211] Further, as shown in FIG. 24, a moiré-dominant structure that does not necessarily limit the gist of the present invention to diffusion in all directions, or a layer that exhibits diffusivity perpendicular to the direction of the stripes of moiré is provided. You may apply. Specifically, a prism-shaped layer (lens sheet) parallel to the structure or stripes can be used. Further, it may be combined with the diffusion layer described above.

[Embodiment 3]

[0213] In the present embodiment, a liquid crystal display device comprising a plurality of superimposed liquid crystal panels In this case, at least one of the inner transparent substrates is thinner than the outer transparent substrate, thereby suppressing the occurrence of moire. Furthermore, it is preferable that the substrates provided with the color filters are adjacent to each other.

FIG. 25 shows an optical path added to the liquid crystal display device 100 shown in FIG.

In the liquid crystal display device 100 shown in FIG. 25, the optical path according to the visual field is the optical path (1) when viewed from the front, and the optical path (2) when viewed from an oblique direction. The optical path (1) looks normal, but in the case of the optical path (2), it passes through the pixels next to the second panel, so the color may change or the image may be blurred depending on the angle and image. This is moire caused by parallax.

[0216] In the example shown in FIG. 26, the inner substrates (2) and (3) are thinner than the outer substrates (1) and (4). Since the light is blocked by the black mask (BM), as a result, the angle at which normal images can be seen is wider than in the case of FIG. As a result, it is possible to suppress the occurrence of moire in an oblique direction due to parallax.

[0217] Further, only with respect to the parallax problem, the inner substrates (2) and (3) can be used by using a glass having a large refractive index.

[0218] The mechanical strength of the panel can be ensured by the outer substrates (1) and (4).

[0219] When a glass substrate is used, a thin substrate can be used from the beginning. Regarding the possible substrate thickness, glass with a force of 0.4 mm, which varies depending on the size of the production line and the liquid crystal panel, can be used as 3 and 4 substrates. As the substrates 1 and 4, a 0.7 mm glass substrate may be used.

[0220] There is also a method of polishing or etching glass. How to etch glass! There is a well-known technology (Japanese Patent No. 3524540, Japanese Patent No. 3523239, etc.). For example, a chemical working solution such as a 15% hydrofluoric acid aqueous solution is used. The parts such as the terminal surface that are not to be etched are coated with an acid-resistant protective material, immersed in the chemical working solution, and the glass is etched, and then the protective material is removed. Etching glass is 0. lmn! Thinner to about 0.4mm.

In this embodiment, when manufacturing the liquid crystal display device 100 shown in FIG. The substrate (substrates 2 and 3) was etched to make it thinner than the outer substrates (substrates 1 and 4). The inner substrate is bonded to two panels with a polarizing plate having a thickness of about 0.2 mm, so it is easier to maintain the strength as a liquid crystal display device than to thin the substrate facing outward. .

In this embodiment, as shown in FIG. 27, color filters may be provided on the inner substrates (2) and (3). Usually, a terminal for connecting to a driver for driving a liquid crystal is often provided on an active matrix substrate. For this reason, when the active matrix substrate is thinned, the mechanical strength of the terminal portion decreases. However, as shown in Fig. 27, only the inner substrate of the color filter substrate (2), (3) is thinned, and the active matrix is formed on the outer substrate (1) (4). It is no longer necessary to reduce the thickness, and the strength of the terminal portion can be maintained. Since the wiring metal layer of the substrate (1) that forms the active matrix may reduce the contrast and display quality in bright places where external light is reflected, the black matrix is placed on the observer side of the wiring metal. Should be formed. For example, this can be achieved by providing a low reflection material layer containing chromium or the like closest to the observer side of the wiring metal.

In this embodiment, it is possible to suppress the occurrence of moire due to parallax, and to reduce the weight even when a plurality of panels are used while maintaining the strength of the liquid crystal display device. Note that this embodiment can be combined with other embodiments.

[Embodiment 4]

[0225] In each of the above embodiments, the two panels of the liquid crystal display device 100 both have color filters. In this embodiment, as shown in FIG. A liquid crystal display device 100 ′ in which a color filter is provided only on the panel will be described.

[0226] Specifically, a color filter is provided on each of the active matrix substrate 30 'and the counter substrate 20 of one panel (first panel). At this time, the active matrix substrate 30 and the counter substrate 20 ′ ′ of the other panel (second panel) are not provided with color filters. Absent. According to this embodiment, since the distance between the color filters becomes a liquid crystal layer thickness on the order of microns, it is possible to more effectively reduce the moire in the oblique viewing angle direction. In other words, only one liquid crystal panel is provided with a color filter, so that when light transmitted through one liquid crystal panel is transmitted through the other liquid crystal panel, color mixing hardly occurs. As a result, it is possible to suppress the occurrence of moire caused by color mixing.

Hereinafter, the present embodiment will be described with reference to FIGS. 28 to 30. FIG. FIG. 28 shows a schematic cross-sectional outline of the liquid crystal display device of the present embodiment based on the present invention. FIG. 29 shows a configuration of a liquid crystal display device including a polarizing plate. FIG. 30 shows a state (BMonTFT) in which the black matrix 24 is directly provided on the TFT element 3 provided on the active matrix substrate 30 ′ constituting the first panel shown in FIG. The black matrix 24 is virtually superimposed on the TFT element 3.

Compared with the liquid crystal display device 100 shown in FIG. 1, the liquid crystal display device 100 shown in FIG. 28 does not form the color filter 21 on the second panel, but forms the color filter only on the first panel. It is different in point. The color filter 21 is formed on the counter substrate facing the active matrix substrate, and the color filter 21 ′ is formed on the active matrix substrate. The color filter 21 provided on the opposite substrate and the color filter 21 provided on the active matrix substrate are red (R) green (G) blue (B) of each color filter as viewed from the lead direction. The positions are matched. Specifically, red in color filter 2 1 is red in color filter 21 ', green in color filter 21 is green in color filter 21', blue in color filter 21 is blue in color filter 21 ' They are configured so that their positions seen from the vertical direction match each other.

[0229] Here, a method for manufacturing the active matrix substrate 30 'will be described. The active matrix substrate 30 and the color filter substrate which is the counter substrate 20 ′ are the same as those in the first embodiment, and thus description thereof is omitted. Further, the counter substrate 20 "can be formed by reducing the power filter forming process in the counter substrate 20 '.

[0230] First, a metal such as a Ti / Al / Ti laminated film is formed on the transparent substrate 10 by sputtering in order to form the scanning signal wiring (gate wiring or gate bus line) 1 and the auxiliary capacitance wiring 2. Then, a resist pattern is formed by a photolithography method. Dry etching is performed using a ching gas to remove the resist. As a result, the scanning signal wiring 1 and the auxiliary capacitance wiring 2 are simultaneously formed on the transparent substrate 10.

[0231] After that, a gate insulating film such as silicon nitride (SiNx), an active semiconductor layer made of amorphous silicon, or the like, an amorphous silicon doped with phosphorus or the like, and a low resistance semiconductor layer also made of amorphous silicon or the like are formed by CVD. , Data signal wiring (source wiring or source nose line) 4, drain lead wiring 5, auxiliary capacitance forming electrode 6 A metal such as AlZTi is formed by sputtering, and a resist pattern is formed by photolithography. The resist is removed by dry etching using an etching gas such as a chlorine-based gas. As a result, the data signal wiring 4, the drain lead wiring 5, and the auxiliary capacitance forming electrode 6 are formed simultaneously.

[0232] The auxiliary capacitance is formed by sandwiching a gate insulating film of about 4000 A between the auxiliary capacitance wiring 2 and the auxiliary capacitance forming electrode 6.

[0233] Thereafter, the TFT element 3 is formed by dry etching the low-resistance semiconductor layer using chlorine gas or the like for source / drain separation.

[0234] Next, a color filter layer having three primary colors (red, green, blue) 21, a black matrix (BM) 24, and the like is formed. First, after applying a negative acrylic photosensitive resin solution in which carbon fine particles are dispersed by spin coating, drying is performed to form a black photosensitive resin layer. Subsequently, the black photosensitive resin layer is exposed through a photomask and then developed to form a black matrix (BM) 24 ′. At this time, in the regions where the first colored layer (for example, red layer), the second colored layer (for example, green layer), and the third colored layer (for example, blue layer) are formed, the opening for the first colored layer, The BM is formed so that an opening for the 2 colored layer and an opening for the 3rd colored layer (each opening corresponds to each pixel electrode) are formed. More specifically, the active matrix substrate 30 ′ has no alignment disorder concealment BM. As shown in FIG. 30, a leakage current that is photoexcited by external light incident on the TFT element 3 In order to prevent this increase, a black matrix 24 ′ serving as a light shielding portion (BM) is formed on the TFT element 3.

[0235] Next, in order to form an interlayer insulating film 7 'functioning as a color filter, a negative acrylic photosensitive resin solution in which pigments of various colors are dispersed is applied by spin coating, and drain drawing is performed. A contact hole 9 for electrically contacting the lead-out wiring 5 and the pixel electrode 8 is formed by a photolithographic method. This process is similarly performed for the red layer, the green layer, and the blue layer, and the color filter 21 is completed. Here, the film thickness of the color filter 21 is about 1. Ίμ χη ^ ΒΜ24, and the film thickness is about 1.3 m.

[0236] Further, the pixel electrode 8 and the vertical alignment film (not shown) are formed in this order.

Note that the present embodiment is an MVA type liquid crystal display device as described above, and the slit pattern 11 is provided in the pixel electrode 8 made of ITO or the like. Specifically, a film is formed by sputtering, a resist pattern is formed by a photolithography method, and etching is performed with an etching solution such as a mixed solution of ferric chloride and hydrochloric acid. The pixel electrode pattern as shown in FIG.

[0238] The active matrix substrate 30 'is thus obtained.

[0239] The operation of the liquid crystal display device 100 'having the above-described configuration according to the present embodiment will be described.

[0240] The pixels of the first panel are driven based on the display signal, and the pixels of the second panel corresponding to the positions of the pixels of the first panel and the positions viewed from the vertical direction of the panel match. Driven corresponding to the first panel. If the part composed of Polarizer A, the first panel, and Polarizer B (Component 1) is in the transmissive state, the part composed of Polarizer B, the second panel, and Polarizer C (Component) 2) is also in a transmissive state, and when component 1 is in a non-transmissive state, component 2 is also driven to be in a non-transmissive state.

[0241] The same image signal may be input to the first and second panels, or different signals associated with each other may be input to the first and second panels. In the following embodiment, an example in which different signals related to each other are input to the first and second panels to display an image will be described.

[0242] [Embodiment 5]

Still another embodiment of the present invention will be described below with reference to FIGS. 31 and 32. FIG. In the present embodiment, drive control for the liquid crystal display device 100 shown in FIG. 1 described in the first embodiment will be described.

[0243] As shown in Fig. 31 (a), consider the case where two upper and lower liquid crystal panels (first panel and second panel) are used. [0244] As shown in Fig. 31 (b), here, the case of a liquid crystal panel having the same resolution will be described. If the same display data is displayed on the first panel and the second panel, the images may interfere with each other. Moire caused by this occurs.

[0245] Therefore, as shown in Fig. 31 (c), by changing the spatial frequency of the display data of the first panel and the second panel, the first panel and the second panel are changed. Interference can be eliminated. Thereby, moire can be reduced.

[0246] As shown in Fig. 31 (c), the control for varying the spatial frequency is performed as follows.

(1) Convert input data to spectrum data using DCT or FFT.

(2) Use a division filter to separate high frequency components and low frequency components.

(3) Restore high-frequency components to the original spatial data using inverse DCT or inverse FFT and display them on the first panel.

(4) Restore the low-frequency component to the original spatial data using inverse DCT or inverse FFT and display it on the second panel.

[0247] Through the above process, the display of the first panel is determined from the difference between the display data and the display of the second panel.

[0248] Note that the above description is performed in one dimension. Since the liquid crystal panel is a surface display, it is performed in two dimensions.

For example, as shown in FIG. 32, specific control includes data input unit 201, synchronization signal generation unit 202, frequency domain converter 203, band division filter 207, inverse frequency domain converter 205, inverse frequency domain transform. This can be realized by the display controller 210 having the device 208.

[0250] The data input unit 201 separates the input data into a synchronization signal and pixel data of each pixel, outputs the separated synchronization signal to the subsequent-stage synchronization signal generation unit 202, and converts the pixel data into the subsequent-frequency domain conversion. Output to 203.

[0251] The synchronization signal generation unit 202 generates a control signal for controlling the source drive means and the gate drive means as well as the synchronization signal power from the data input unit 201.

[0252] For example, the following three types of control signals are generated as the control signals for the source driving means.

(1) Source start pulse (2) Source latch panoramic

(3) Source clock

In addition, the following two types of control signals are generated as control signals for the gate drive means.

(1) Gate start pulse

(2) Gate shift clock

The frequency domain change 203 converts the pixel data from the data input unit 201 into spatial frequency data, and outputs the spatial frequency data to the subsequent band division filter 207. Typical examples of frequency domain transformation include 2D FFT transformation and 2D DCT transformation.

[0253] The band-splitting filter 207 divides the data in the high frequency region and the data in the low frequency region, and outputs the data in the low frequency region to the inverse frequency region converter 205 connected to the source driving means of the liquid crystal panel B. In addition, the high frequency region data is output to the inverse frequency region changer 208 connected to the source driving means of the liquid crystal panel A.

[0254] If the frequency data is only divided into two, a low-pass filter and a high-pass filter may be used.

[0255] Here, in the case of the band division filter, since it can be divided into data of multiple frequency domains,

, It has the merit of being able to handle multiple panels.

[0256] The inverse frequency domain converter 205 performs the inverse transformation of the frequency domain transformation 203 on the low frequency domain data, and uses the data after the inverse transformation as the pixel data of the second panel.

The output is output to the source driving means of the second panel.

[0257] The inverse frequency domain converter 208 performs the inverse transformation of the frequency domain transformation 203 on the high frequency domain data, and uses the data after the inverse transformation as the pixel data of the first panel.

The signal is output to the source driving means of the first panel.

Here, as the inverse frequency conversion in the inverse frequency domain transformations 205 and 208, inverse two-dimensional FFT transformation, inverse two-dimensional DCT transformation, and the like are performed.

[0259] As described above, if different signals related to each other are input to the first panel and the second panel to display an image, deterioration of display quality due to moire can be prevented. In addition, it is possible to provide a liquid crystal display device capable of displaying an image with a very high display quality with an improved color reproduction range.

[Embodiment 6]

Still another embodiment of the present invention will be described below with reference to FIGS. 33 and 34. FIG. In the present embodiment, drive control for the liquid crystal display device 100 shown in FIG. 1 described in the first embodiment will be described.

[0261] As shown in Fig. 33 (a), consider the case of using two liquid crystal panels (first panel and second panel) stacked one above the other. Here, as shown in Fig. 33 (b), the resolution of the second panel is assumed to be lower than the display resolution.

[0262] Therefore, as shown in Fig. 33 (c), by changing the spatial frequency of the display data of the first panel and the second panel, the first panel and the second panel are changed. Interference between images can be reduced. Thereby, moire can be reduced.

[0263] As shown in Fig. 33 (c), the control to vary the spatial frequency is performed as follows.

(1) Convert input data to spectrum data using DCT or FFT.

(2) Use a low-pass filter to divide into low frequency components.

(3) The low-frequency component is restored to the original spatial data using inverse DCT or inverse FFT and displayed on the second panel. At this time, since the resolution is low, the number of samplings is thinned accordingly.

(4) The actual display data is the display on the first panel X the display on the second panel.

[0264] Through the above process, the display of the first panel is determined from the difference between the display data and the display of the second panel.

[0265] Note that the above description is a one-dimensional force. Since the liquid crystal panel is a surface display, it is a two-dimensional display.

[0266] Also, the resolution on the panel structure is the same as A and B, and even if the same signal is input to multiple source bus lines on the second panel to reduce the display resolution on the second panel. Good.

For example, as shown in FIG. 34, specific control includes a data input unit 201, a synchronization signal generation unit 202, a frequency domain converter 203, a low-pass filter 204, an inverse frequency domain converter 205, and a difference calculator 206. This can be realized by the display controller 200 provided. [0268] The data input unit 201 separates the input data into a synchronization signal and data of each pixel, outputs the separated synchronization signal to the subsequent-stage synchronization signal generation unit 202, and outputs the pixel data (pixel data) to the subsequent stage. Output to the frequency domain converter 203 and the difference calculator 206.

[0269] The synchronization signal generation unit 202 generates a control signal for controlling the source drive means and the gate drive means as well as the synchronization signal power from the data input unit 201.

[0270] For example, the following three types of control signals are generated as the control signals for the source driving means.

(1) Source start pulse

(2) Source latch panoramic

(3) Source clock

(1) Gate start pulse

(2) Gate shift clock

The frequency domain change 203 converts the pixel data from the data input unit 201 into spatial frequency data, and outputs the spatial frequency data to the low-pass filter 204 at the subsequent stage. Typical examples of frequency domain transformation include 2D FFT transformation and 2D DCT transformation.

[0271] The low-pass filter 204 passes only the low-frequency domain data from the frequency data from the frequency domain transformation 203, and outputs the low-frequency domain data to the reverse frequency domain transformation 205 in the subsequent stage. RU

[0272] The inverse frequency domain converter 205 performs the inverse transformation of the frequency domain transformation 203 on the low frequency domain data, and uses the data after the inverse transformation as the pixel data of the liquid crystal panel B. In addition to being output to the source driving means, it is also output to the difference calculator 206.

[0273] Here, in the inverse frequency domain transformation 205, as the inverse frequency transformation, inverse two-dimensional FFT transformation, inverse two-dimensional DCT transformation, etc. are performed, and sampling points are combined with the pixels of the liquid crystal panel Β. Decimation of numbers is performed.

[0274] The difference calculator 206 calculates the difference between the data from the data input unit 201 which is the original data and the data on the liquid crystal panel B from the inverse frequency domain converter 205, and displays the original data. Thus, the pixel data of the first panel is corrected so that the corrected pixel data is output to the source driving means of the first panel.

[0275] This embodiment is more suitable when combined with Embodiment 4 described above. As can be seen from FIG. 28, in the fourth embodiment, the second panel is monochrome. The pixel corresponding to RGB in the first panel may be used as one pixel, and the resolution may be 1Z3. This configuration is advantageous in terms of transmittance because the second panel does not require an RGB signal line. In addition, problems due to parallax can be reduced.

[Embodiment 7]

The following will describe still another embodiment of the present invention. In the present embodiment, in the liquid crystal display device described in each of the above-described embodiments, measures for improving the saturation reduction due to the γ value of the image data output from the first panel and the second panel are described. To do. When a plurality of panels are stacked, the saturation may decrease due to parallax or the like. In this embodiment, a case where a color panel (that is, the first panel in Embodiment 4) is used as the first panel and a monochrome panel (that is, the second panel in Embodiment 4) is used as the second panel is described. The same effect can be obtained if both panels are color panels.

[0277] A method for driving a liquid crystal display device according to the present embodiment will be described with reference to the following examples.

[0278] (Example)

In the case of a display, the γ value is expressed as i = kX E k = constant> as input signal (gradation) Ε and output (brightness) i, and logi = logk + y 'logE. Become.

[0279] Since γ of TV signal is specified by G = 0.45, generally γ of the display is G =

out

2. About 2. However, in an actual display device such as a liquid crystal display device, it is almost impossible for black to have the same gamma for all gradations due to the fact that black is not 0 brightness and signal processing such as saturation adjustment. It is distributed continuously about 8 ~ 2.6. [0280] For this reason, the above γ is not a constant straight line in all gradations but is a curve, and γ is defined as the slope of the tangent line in each gradation. Approximate to the slope of a straight line between tones).

[0281] This γ value is described as a function G (χ) of gradation X, the γ value of the image data output from the color panel is G (χ), and the γ value of the image data output from the monochrome panel is G (χ)

1 1 2 The γ value of the final output image data is G (x) = G (x) + G (x). Where out 1 2

In the present invention, the γ value G (X) force G (X) = G (X) + G out 1 in at least one gradation X

(X) and satisfy the relationship of G (X)> G (X).

2 1 2

[0282] Specifically,

In this example, the output γ is about 2.4 in an area of about 10 gradations (X> 10).

Thus, G (γ) = 2.2 for the image data output from the color panel, and G (χ) = 0.2 for the image data output from the black-and-white panel. About 10 gradations or less

twenty two

In the region (X 10), the color panel alone has a low CR, so it is output from the color panel.

2

Since the 0 value of the generated image data is almost 0, G (X) = 0, which is about 10 gradations or less.

1 1 2

Γ of the image data output from the monochrome panel of the area

The two values are G (χ) = 1.7

Therefore, the γ value of the output image data achieves almost 2.4 in all gradation areas (Figure out).

35, see Figure 36).

[0283] In this example, the relationship of G (X)> G (X) is satisfied in almost the entire region of 10 gradations or more.

1 2

Although it is set, the force that satisfies the relationship of G (X)> G (X) with at least one gradation

1 2

Saturation improvement effect at gradation X is obtained. In that case, G (X) for other gradations X

3 1 3

= G (X) is desirable from the viewpoint of the saturation improvement effect.

twenty three

Since the saturation can be improved by using other saturation improvement measures together, G (X) <G (X

1 3 2

There may be other gradations that are related to each other.

Three

[0284] Further, γ of a monochrome panel with 10 gradations or less may have an inflection point as shown in Figs. 37 and 38. In this case, an image with more emphasized black is obtained.

[0285] As described above, setting the color between the color panel and the black and white panel _improves the saturation reduction, eliminates the image blur caused by the parallax between the black and white panel and the color panel, and has sufficient contrast. A liquid crystal display device can be obtained. [0286] These γ settings are the ones that define the output image for the input signal, and are obtained by measuring the brightness of the image data output for the input signal.

[0287] The input signal is a video source or a display signal based thereon.

[0288] The y setting may be performed by the controller of the liquid crystal panel, the output signal processing circuit to the liquid crystal controller, or both.

[0289] In addition, even when the active γ technology that changes the γ value according to the input signal is used in combination, the same effect as that of the force that exists in the first panel and the second panel can be obtained.

[0290] At this time, the larger the Ύ value of the image data output from the first panel, the more effective it is.

1. A saturation reduction suppressing effect sufficient for practical use can be obtained by setting the ratio to 1.8 or more.

[0291] Furthermore, by making the grayscale data correspond to the maximum grayscale of the RGB signals in the black-and-white panel data, it is possible to obtain a good image that avoids interference occurring between the panels in addition to the above effects.

[0292] Further, by performing smoothing processing on the display signal of the black-and-white panel, there is an effect that the image misalignment between the two panels when viewed obliquely is also visually recognized.

[0293] Furthermore, by setting the γ value of the image output from the first panel to be G (χ)> 0 in all gradations, the liquid crystal panel is able to reduce the blackened image that occurs because the contrast is limited. After correction, an image with a higher contrast is obtained (see Fig. 39 and Fig. 40).

[0294] Furthermore, as shown in the above-described Embodiments 5 and 6, by changing the spatial frequency of the display data of the first panel and the second panel, interference occurring between the panels can be avoided, and as a result Since the luminance value of the original signal is not changed and the chromaticity value of each pixel is retained, the luminance change in the plane direction of the lower CF-free panel is smooth without any loss of saturation. In this case, the image misalignment between the two panels is also visually recognized.

[Embodiment 8]

A television receiver to which the liquid crystal display device of the present invention is applied will be described below with reference to FIGS.

FIG. 41 shows a circuit block of a liquid crystal display device 601 for a television receiver.

[0297] As shown in FIG. 34, the liquid crystal display device 601 includes a YZC separation circuit 500, a video chroma circuit 501, an AZD converter 502, a liquid crystal controller 503, a liquid crystal non-504, and a backlight drive. The configuration includes a dynamic circuit 505, a backlight 506, a microcomputer 507, and a gradation circuit 508.

[0298] The liquid crystal panel 504 has a two-panel configuration of a first liquid crystal panel and a second liquid crystal panel, and may have any of the configurations described in the above embodiments.

In the liquid crystal display device 601 having the above configuration, first, an input video signal of a television signal is input to a YZC separation circuit 500 and separated into a luminance signal and a color signal. The luminance and color signals are converted to R, G, and B, which are the three primary colors of light, by the video chroma circuit 501, and this analog RGB signal is converted to a digital RGB signal by the AZD converter 502. Input to controller 503.

In the liquid crystal panel 504, the RGB signal from the liquid crystal controller 503 is input at a predetermined timing, and the RGB gradation voltages from the gradation circuit 508 are supplied to display an image. The microcomputer 507 controls the entire system including these processes.

[0301] The video signal can be displayed based on various video signals such as a video signal based on television broadcasting, a video signal captured by a camera, and a video signal supplied via the Internet line. .

Furthermore, the tuner unit 600 shown in FIG. 42 receives a television broadcast and outputs a video signal, and the liquid crystal display device 601 displays an image (video) based on the video signal output from the tuner unit 600. Do.

[0303] When the liquid crystal display device having the above configuration is a television receiver, for example, as shown in FIG. 43, the liquid crystal display device 601 is wrapped in a first housing 301 and a second housing 306. It is a structure that is held between.

[0304] The first casing 301 is formed with an opening 301a through which an image displayed on the liquid crystal display device 601 is transmitted.

[0305] The second casing 306 covers the back side of the liquid crystal display device 601. An operation circuit 305 for operating the liquid crystal display device 601 is provided, and a support member is provided below. 308 is attached!

[0306] As described above, in the television receiver having the above-described configuration, the liquid crystal according to the present invention is included in the display device. By using a crystal display device, it is possible to display an image with a very high display quality with a high contrast and color reproduction range.

[0307] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. Such embodiments are also included in the technical scope of the present invention. Industrial applicability

[0308] Since the liquid crystal display device of the present invention can greatly improve contrast, it can be applied to television receivers, broadcast monitors, and the like.

Claims

The scope of the claims

[I] In a liquid crystal display device with two or more liquid crystal panels stacked,

Among the plurality of liquid crystal panels, in at least two liquid crystal panels, a color filter is provided on an insulating substrate constituting the liquid crystal panel.

2. The liquid crystal display device according to claim 1, wherein the polarization absorbing layer is provided in a cross-col relationship with the liquid crystal panel interposed therebetween.

[3] The liquid crystal display device according to [1] or [2], wherein the insulating substrates provided with the color filters are arranged adjacent to each other.

[4] The feature is that the thickness of at least one insulating substrate adjacent to each other of the stacked liquid crystal panels is thinner than the thickness of the insulating substrates not adjacent to each other. The liquid crystal display device according to any one of claims 1 to 3.

[5] The number of the insulating substrates provided with the color filter is two, and the insulating substrates are an active matrix substrate of one liquid crystal panel and an insulating substrate opposite to the active matrix substrate. 4. The liquid crystal display device according to any one of items 1 to 3.

6. The liquid crystal display device according to any one of claims 1 to 5, wherein a light diffusing layer having light diffusibility is provided on at least one of the superposed liquid crystal panels. .

7. The liquid crystal display device according to claim 6, wherein the light diffusion layer is provided on a display surface side of the superimposed liquid crystal panel.

8. The liquid crystal display device according to claim 6, wherein the light diffusion layer is provided between the stacked liquid crystal panels.

9. The liquid crystal display device according to claim 6, wherein the light diffusion layer is provided between the display surface side of the overlapped liquid crystal panel and the overlapped liquid crystal panel.

[10] At least two polarization absorption layers are provided between the stacked liquid crystal panels, and a light diffusion layer is provided between the at least two polarization absorption layers. Claims

6. The liquid crystal display device according to 6.

[II] Illumination device that emits force light on the opposite side of the display surface to the superimposed liquid crystal panel Is provided,

11. The power according to claim 1, wherein the lighting device has a light source having a peak in a green region of visible light, and the wavelength power of the peak is in a range of 05 nm to 540 nm. Liquid crystal display device.

[12] The liquid crystal display device according to claim 11, wherein a wavelength power of a peak in a green region of visible light of the light source is 520 nm.

[13] The light source of the illumination device is a fluorescent lamp, and the phosphor of the fluorescent lamp is made of BaMgAl 2 O 3

The liquid crystal display device according to claim 12, wherein the liquid crystal display device is 10 17.

[14] A method of driving a liquid crystal display device in which each of the liquid crystal panels in the liquid crystal display device according to any one of claims 1 to 13 outputs image data based on a video source,

When the outermost LCD panel is the first LCD panel,

The γ value of the image data output from the liquid crystal display device is γ = G (X) (x is any out

Gradation), γ = G (x) of the image data output from the first liquid crystal panel, and γ = G (x) of the image data output from another liquid crystal panel, at least one gradation X In

twenty two

Γ = G (X) force G (X) = G (X) + G (X) and satisfies the relationship of G (X)> G (X) out 1 2 1 2

A method for driving a liquid crystal display device.

15. The method for driving a liquid crystal display device according to claim 14, wherein the first liquid crystal panel is a color liquid crystal panel, and the other at least one liquid crystal panel is a black and white liquid crystal panel.

16. The gradation of one pixel of the monochrome liquid crystal panel is a gradation corresponding to a maximum gradation signal among pixel signals constituting one picture element of a video source. A driving method of the liquid crystal display device described.

17. The method for driving a liquid crystal display device according to claim 16, wherein the image data output from the black and white liquid crystal panel is smoothed.

[18] The black gradation X vicinity is such that G (X) <G (X).

2 1 2 2 2

2. A method for driving a liquid crystal display device according to item 1.

[19] The γ values of the image data output from the color liquid crystal panel are all gradations. 19. The method for driving a liquid crystal display device according to any one of claims 14 to 18, wherein (X)> 0 (not 0).

[20] In the black gradation X, G (X) ≥ 1.8.

2. A method for driving a liquid crystal display device according to item 1.

[21] In a television receiver including a tuner unit that receives a television broadcast and a display device that displays the television broadcast received by the tuner unit.

A television receiver using the liquid crystal display device according to any one of claims 1 to 13 for the display device.