Liquid crystal display device

Abstract

Provided is a liquid crystal display device capable of switching between a privacy mode and a public mode and achieving high contrast even when displayed in the privacy mode. The liquid crystal display device of the present invention is a liquid crystal display device provided with a liquid crystal panel and a control circuit, an active matrix substrate has a first substrate, a first electrode, a first insulating layer, and a plurality of second electrodes having a first linear electrode portion, the color filter substrate has a second substrate, a black matrix, a color filter, a third electrode, and a fourth electrode disposed between the black matrix and the third electrode and applied with a constant voltage, the third electrode includes a second linear electrode portion and overlaps at least a portion of the black matrix when viewed from above, and the control circuit controls switching to apply a driving voltage and a constant voltage to the third electrode.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a liquid crystal display device. BACKGROUND

[0002] A liquid crystal display device is a display device that utilizes a liquid crystal composition for display, and a representative display mode thereof is to apply a voltage to a liquid crystal composition enclosed between a pair of substrates, change the alignment state of liquid crystal molecules in the liquid crystal composition according to the applied voltage, and thereby control the light transmittance. Such a liquid crystal display device has the advantages of thinness, lightness, and low power consumption, and is used in a wide range of fields.

[0003] In the past, there have been studies on liquid crystal display devices to improve the viewing angle characteristics in such a manner that the same image can be observed even from a narrow viewing angle range and even from a wide viewing angle range. On the other hand, from the viewpoint of privacy protection, although an image can be observed from a narrow viewing angle range, there are studies on display methods in which it is difficult to observe the above-mentioned image from a wide viewing angle range. For example, in Patent Literature 1, a liquid crystal display device is disclosed in which a narrow viewing angle mode and a wide viewing angle mode can be switched by controlling the voltage applied to a third electrode provided on a color filter substrate.

[0004] Patent Literature 2 discloses a liquid crystal display device provided with a first substrate having a first electrode and a first alignment film, a liquid crystal layer, and a second substrate having a second electrode, a third electrode, and a second alignment film, in which the viewing angle is switched by applying a voltage to the above-mentioned first electrode.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] [Patent Literature 1] Japanese Patent Application Publication No. 2021-67852 [Patent Literature 2] U.S. Patent Application Publication No. 2017 / 0059898 [Patent Literature 3] Japanese Patent Application Publication No. 2002-124112 SUMMARY

[0008] Technical problem to be solved by the invention

[0009] According to the research by the present inventors, when a voltage is applied to an electrode provided on a color filter substrate having a black matrix, light leakage occurs in the case of display in a privacy mode (narrow viewing angle mode), and sometimes the front contrast ratio decreases. The present inventors have researched the cause of the above-mentioned light leakage, and found that when a voltage is applied to an electrode provided on a color filter substrate, the black matrix is charged (charged), an unwanted electric field is formed in a liquid crystal layer, as a result, light leakage occurs, and in the privacy mode, the front contrast ratio decreases.

[0010] The liquid crystal display device disclosed in the above-described Patent Document 2 has a problem in that it is difficult to obtain a high front contrast because a first electrode on a counter substrate side is a flat-plate-shaped full-surface electrode, and thus a longitudinal electric field is generated in the entire liquid crystal panel in-plane when a voltage is applied to the first electrode.

[0011] The present application has been achieved in view of the above-described circumstances, and an object thereof is to provide a liquid crystal display device capable of switching between a privacy mode and a public mode, and capable of achieving a high contrast even in the case of display in the privacy mode.

[0012] Technical solution for solving the technical problem

[0013] (1) A liquid crystal display device according to an embodiment of the present application includes: a liquid crystal panel in which a plurality of pixels are arranged in a matrix shape; and a control circuit, the liquid crystal panel sequentially has an active matrix substrate, a liquid crystal layer, and a color filter substrate, the active matrix substrate sequentially has: a first substrate; a first electrode; a first insulating layer; and a plurality of second electrodes arranged for each of the pixels and having a first linear electrode portion extending in a first direction, the color filter substrate has: a second substrate; a black matrix arranged between the plurality of pixels; a color filter; a third electrode; and a fourth electrode arranged between the black matrix and the third electrode and applied with a constant voltage, the third electrode includes a second linear electrode portion extending in a second direction intersecting the first direction and overlapping at least a part of the black matrix when viewed from above, and the control circuit controls switching of application of a driving voltage and application of a constant voltage to the third electrode.

[0014] (2) Furthermore, a liquid crystal display device according to an embodiment of the present application is configured as described in (1) above, and the third electrode includes a third linear electrode portion extending in the second direction and arranged so as to overlap an optical opening portion of the pixel when viewed from above.

[0015] (3) Furthermore, a liquid crystal display device according to an embodiment of the present application is configured as described in (2) above, and the fourth electrode overlaps the third linear electrode portion in the optical opening portion of the pixel.

[0016] (4) Furthermore, a liquid crystal display device according to an embodiment of the present application is configured as described in (2) above, and the fourth electrode is provided with an opening at a position overlapping the third linear electrode portion when viewed from above.

[0017] (5) Furthermore, a liquid crystal display device according to an embodiment of the present application is configured as described in any one of (1) to (4) above, and the color filter substrate sequentially has the second substrate, the black matrix, the color filter, a first dielectric layer, the fourth electrode, a second dielectric layer, and the third electrode.

[0018] (6) Furthermore, the liquid crystal display device of one embodiment of the present application includes the color filter substrate including the second substrate, the black matrix, the fourth electrode, the color filter, the second dielectric layer, and the third electrode, in any of (1) to (4).

[0019] (7) Furthermore, the liquid crystal display device of one embodiment of the present application includes the third dielectric layer between the third electrode and the liquid crystal layer, in (5) or (6).

[0020] (8) Furthermore, the liquid crystal display device of one embodiment of the present application includes the third electrode formed of a transparent conductive material, in any of (1) to (7).

[0021] (9) Furthermore, the liquid crystal display device of one embodiment of the present application includes the active matrix substrate including a gate wire and a source wire arranged so as to cross the gate wire, the gate wire extending in the second direction, in any of (1) to (8).

[0022] (10) Furthermore, the liquid crystal display device of one embodiment of the present application includes the second linear electrode portion overlapping with the gate wire at least in part in plan view, in (9).

[0023] (11) Furthermore, the liquid crystal display device of one embodiment of the present application includes the control circuit capable of switching between a first display mode and a second display mode, the first display mode displaying a first image that can be observed from a narrow viewing angle range including a normal direction of the liquid crystal panel, the second display mode enabling the first image to be observed from a wide viewing angle range including the narrow viewing angle range, the control circuit performing control to apply the driving voltage to the third electrode in the first display mode and to apply the constant voltage to the third electrode in the second display mode, in any of (1) to (10).

[0024] (12) Furthermore, the liquid crystal display device of one embodiment of the present application includes the backlight including a light source and a light-shielding shutter provided on the liquid crystal panel side of the light source, on the back surface of the liquid crystal panel, in (11), and the control circuit performs control such that the luminance of the backlight in the first display mode is lower than that in the second display mode.

[0025] Advantages

[0026] According to the present application, it is possible to provide a liquid crystal display device capable of switching between a privacy mode and a public mode, and achieving high contrast even in the case of display in the privacy mode. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a plan view showing a portion of the liquid crystal panel exemplified in the first embodiment.

[0028] Figure 2 is a cross-sectional view of the X1-X1' line of Figure 1 .

[0029] Figure 3 is a cross-sectional view of the Y-Y' line of Figure 1 .

[0030] Figure 4 is a cross-sectional view showing an example in which a third dielectric layer is provided on the liquid crystal panel shown in Figure 2 .

[0031] Figure 5A is a plan view of one pixel of the liquid crystal panel exemplified in the second embodiment.

[0032] Figure 5B is a plan view of the fourth electrode shown in Figure 5A .

[0033] Figure 6 is a cross-sectional view of the X2-X2' line of Figure 5A .

[0034] Figure 7 is a plan view showing one pixel of another example of the second embodiment.

[0035] Figure 8 is a cross-sectional view along the X3-X3' line of Figure 7 .

[0036] Figure 9 is a cross-sectional view showing an example in which a third dielectric layer is provided on the liquid crystal panel shown in Figure 8 .

[0037] Figure 10 is a cross-sectional view of the liquid crystal panel exemplified in the third embodiment.

[0038] Figure 11A is a plan view of one pixel of the liquid crystal panel exemplified in the fourth embodiment.

[0039] Figure 11B is a plan view of the fourth electrode shown in Figure 11A .

[0040] Figure 12 yes Figure 11A A schematic diagram of the cross-section of line X4-X4'.

[0041] Figure 13A This is a planar schematic diagram of a pixel representing another example of the fourth embodiment.

[0042] Figure 13B yes Figure 13A A schematic diagram of the fourth electrode is shown.

[0043] Figure 14 yes Figure 13A A schematic diagram of the cross-section of line X5-X5'.

[0044] Figure 15 This is a block diagram schematically illustrating the display methods of the first display mode and the second display mode in the fifth embodiment.

[0045] Figure 16 This is a planar schematic diagram illustrating an example of a display unit that a liquid crystal panel has.

[0046] Figure 17 This is a plan view illustrating an example of a color element displayed in color using a veil-view function.

[0047] Figure 18 This is a block diagram schematically illustrating the display method in the case of displaying a viewing angle control pattern in the fifth embodiment.

[0048] Figure 19 This is an exploded perspective view schematically showing the backlight of the shading louvers used in the sixth embodiment.

[0049] Figure 20 This is a block diagram schematically illustrating the display methods of the first display mode and the second display mode in the sixth embodiment.

[0050] Figure 21 This is a block diagram schematically illustrating the display method in the case of displaying a viewing angle control pattern in the sixth embodiment.

[0051] Figure 22 This is a cross-sectional schematic diagram of the liquid crystal panel of Comparative Example 1.

[0052] Figure 23 The graph shows the contrast ratio of Comparative Example 1, and the simulation results show the transmittance of a single pixel.

[0053] Figure 24 This is a contrast curve of Example 1 and a simulation result of the transmittance of a pixel.

[0054] Figure 25is a graph of the contrast ratio and a simulation result of the transmittance of one pixel of Comparative Example 2.

[0055] Figure 26 is a graph of the contrast ratio and a simulation result of the transmittance of one pixel of Comparative Example 2.

[0056] Figure 27A is a cross-sectional view of a liquid crystal panel of Comparative Example 2.

[0057] Figure 27B is a plan view of the third electrode shown in Figure 27A

[0058] Figure 28 is a graph comparing the contrast ratios of Examples 1, 4, 5, and Comparative Example 2. DETAILED DESCRIPTION

[0059] Hereinafter, an embodiment of the present application will be described. The present application is not limited to the content described in the following embodiment, and design changes can be appropriately made within a range satisfying the configuration of the present application. In addition, in the following description, the same parts or parts having the same function are appropriately shared between different drawings using the same reference numerals, and the repeated description is appropriately omitted. Each mode of the present application can also be appropriately combined without departing from the spirit of the present application.

[0060] <First Embodiment>

[0061] The liquid crystal display device of the first embodiment is a liquid crystal display device having a liquid crystal panel in which a plurality of pixels are arranged in a matrix shape and a control circuit, the liquid crystal panel having, in order, an active matrix substrate, a liquid crystal layer, and a color filter substrate, the active matrix substrate having, in order, a first substrate, a first electrode, a first insulating layer, and a plurality of second electrodes, the plurality of second electrodes having a first linear electrode portion arranged per the pixel and extending in a first direction, the color filter substrate having a second substrate, a black matrix arranged between the plurality of pixels, a color filter, a third electrode, and a fourth electrode arranged between the black matrix and the third electrode and applied with a constant voltage, the third electrode including a second linear electrode portion extending in a second direction crossing the first direction and overlapping at least a part of the black matrix when viewed from above, the control circuit performing control to switch between applying a driving voltage and the constant voltage to the third electrode.

[0062] The liquid crystal display device of the first embodiment will be described below using the drawings. Figure 1 is a plan view showing a part of the liquid crystal panel exemplified in the first embodiment. Figure 2 is a cross-sectional view along the X1-X1' line of Figure 1 Figure 3 is a cross-sectional view along the X2-X2' line of​​Figure 1 A schematic diagram of the cross-section of the Y-Y' line.

[0063] (LCD panel)

[0064] like Figure 1 As shown, the liquid crystal display device of the first embodiment has a liquid crystal panel 100A with a plurality of pixels arranged in a matrix. The active matrix substrate may also have gate wiring 1 and source wiring 2 arranged intersecting with the gate wiring 1. In this specification, "pixel" refers to... Figure 1 The area shown is surrounded by two adjacent gate wirings 1 and two adjacent source wirings 2. In this specification, unless otherwise specified, the first pixel 70 and the second pixel 71 described later are simply referred to as pixels. A thin film transistor 3 (TFT) may also be configured as a switching element at the intersection of the gate wiring 1 and the source wiring 2.

[0065] Preferably, optical openings are provided in multiple pixels, and these optical openings are configured to allow light to pass through the liquid crystal panel 100A. The aforementioned optical openings are... Figure 1 The area inside the pixel shown is enclosed by a dashed line. When the liquid crystal panel 100A is a transmissive or semi-transmissive type, the opening of the aforementioned optical element allows light emitted from the back of the liquid crystal panel 100A to be transmitted towards the front surface of the liquid crystal panel 100A. When the liquid crystal panel 100A is a reflective or semi-transmissive type, the opening of the aforementioned optical element allows incident light incident from the outside of the liquid crystal panel 100A and reflected light reflected from the inside of the liquid crystal panel 100A and emitted towards the outside of the liquid crystal panel 100A to be transmitted. Furthermore, the opening of the aforementioned optical element may overlap with transmissive components such as polarizers or color filters when viewed from above. In this specification, "viewing from above" refers to viewing the liquid crystal panel from the normal direction. In the first embodiment, the case where the liquid crystal panel 100A is a transmissive type will be described.

[0066] like Figure 2 and Figure 3 As shown, the liquid crystal panel 100A sequentially includes an active matrix substrate 10, a liquid crystal layer 20, and a color filter substrate 30. In this specification, the side closer to the screen of the liquid crystal display device is referred to as the "observer side (front side)," and the side farther from the screen of the liquid crystal display device is referred to as the "back side." The view from the normal direction of the front side is also called a top view.

[0067] The active matrix substrate 10 sequentially comprises a first substrate 11, a first electrode 12, a first insulating layer 13, and a plurality of second electrodes 14. The first electrode 12 and the second electrode 14 are stacked with the first insulating layer 13 in between, forming an FFS (Fringe Field Switching) type electrode structure. For example, inorganic materials such as silicon oxide and silicon nitride can be used as the material for the first insulating layer 13.

[0068] In the first embodiment, the first electrode 12 is preferably a full-surface electrode. A full-surface electrode refers to a flat electrode that, when viewed from above, does not have slits or openings in the area overlapping with the optical opening of a pixel. The first electrode 12 can be configured for multiple pixels, configured for multiple pixels in a shared manner, or formed throughout the entire display area regardless of pixel boundaries. Examples of materials for the first electrode 12 include transparent conductive materials such as indium tin oxide (ITO) and indium zinc oxide (IZO).

[0069] like Figure 1 As shown, each pixel is configured with a second electrode 14. The second electrode 14 includes a first linear electrode portion 14a extending along a first direction D1. At least a portion of the second electrode 14 may extend along the first direction D1, or it may include a linear electrode portion extending in a direction different from the first direction D1. There may be multiple first linear electrode portions 14a. The ends of adjacent first linear electrode portions 14a may be connected by an electrode material, and an opening surrounded by the electrode material may be provided. Furthermore, the second electrode 14 may be a comb-tooth electrode that releases the ends of adjacent first linear electrode portions 14a, and slits may be provided between adjacent first linear electrode portions 14a. Figure 1 In the example shown, the ends of a plurality of first linear electrode portions 14a are connected by electrode material and are provided with openings 14b.

[0070] The width of the first linear electrode portion 14a can be, for example, 2 to 5 μm. The width of the slit or opening can be, for example, 2 to 5 μm. The width of the first linear electrode portion 14a, the width of the slit or opening are the widths in the direction orthogonal to the first direction D1.

[0071] The material used for the second electrode 14 can be, for example, a transparent conductive material such as ITO or IZO. The second electrode 14 is electrically connected to the corresponding source wiring 2 via, for example, the semiconductor layer of the TFT 3.

[0072] Preferably, either the first electrode 12 or the second electrode 14 is electrically coupled across the plurality of pixels. "Across the plurality of pixels" means configured to overlap with the plurality of pixels across their boundaries. By electrically coupling across the plurality of pixels, a common constant voltage can be applied to the plurality of pixels through either the first electrode 12 or the second electrode 14.

[0073] There is no particular limitation on the first substrate 11 and the second substrate 31 to be described later, and for example, a resin substrate such as polycarbonate, a glass substrate, or the like can be used.

[0074] The liquid crystal layer 20 contains liquid crystal molecules. The liquid crystal molecules are preferably liquid crystal molecules (positive type) in which the dielectric anisotropy (Δε) defined by the following formula (L) has a positive value. Further, the liquid crystal molecules are preferably uniformly oriented in a state in which no voltage is applied (voltage non-application state). The direction of the long axis of the liquid crystal molecules in the voltage non-application state is also referred to as the direction of the initial alignment of the liquid crystal molecules. The above-described voltage non-application state includes a case where a voltage smaller than the threshold value of the liquid crystal molecules is applied to the liquid crystal layer.

[0075] Δε = (dielectric constant in the direction of the long axis of the liquid crystal molecules) - (dielectric constant in the direction of the short axis of the liquid crystal molecules) (L)

[0076] The color filter substrate 30 has a second substrate 31, a black matrix 33, a color filter 32, a third electrode 34, and a fourth electrode 36. In the first embodiment, a case where the color filter substrate 30 has the second substrate 31, the black matrix 33, the color filter 32, the first dielectric layer 50, the fourth electrode 36, the second dielectric layer 35, and the third electrode 34 in this order is described.

[0077] The third electrode 34 includes a second linear electrode portion 34a extending in a second direction D2 intersecting the first direction D1. The above-described first direction D1 is the direction in which the first linear electrode portion 14a of the second electrode 14 extends. The second linear electrode portion 34a can also be said to be a transverse stripe electrode with respect to the above-described first direction D1. The second linear electrode portion 34a is a transverse stripe electrode, and thus, for example, compared to a case where the second linear electrode portion 34a is arranged in the same direction as the above-described first direction D1 (a case of a longitudinal stripe electrode), a case where the black matrix 33 is the same shape, or the like, it is possible to improve the privacy performance. Specifically, it is possible to improve the front contrast ratio when displayed in the privacy mode, and to reduce the contrast ratio in a case of viewing from the left and right directions (for example, when viewing the liquid crystal panel from an azimuth of 0° or 180° at a polar angle of 45°). As will be described later, by applying a driving voltage to the third electrode 34, it is possible to generate an electric field in the thickness direction of the liquid crystal layer 20, and it is possible to switch between the privacy mode and the public mode.

[0078] The angle θ1 formed by the above-described first direction D1 and the above-described second direction D2 is preferably 80° or more and 100° or less, and more preferably 85° or more and 95° or less. The second direction D2 can be parallel to the absorption axis 62A of the second polarizing plate 62 or the absorption axis 61A of the first polarizing plate 61, and in the first embodiment, as shown in FIG. 1, the second direction D2 is parallel to the absorption axis 61A of the first polarizing plate 61 (0°-180° azimuth). Figure 1 ​

[0079] The plurality of second linear electrode portions 34a are preferably electrically connected to each other. The plurality of second linear electrode portions 34a may, for example, also be connected at the end portion of the liquid crystal panel by a connection portion. The plurality of second linear electrode portions 34a and the above-described connection portion can also be combined to form a third electrode 34.

[0080] The third electrode 34 overlaps at least a portion of the black matrix 33 in plan view. When the third electrode 34 overlaps at least a portion of the black matrix 33, if it is a conventional liquid crystal display device, the black matrix 33 is charged in the case where a voltage is applied to the third electrode 34 (see FIG. 6). However, even if the third electrode 34 overlaps at least a portion of the black matrix 33, in the present embodiment, by providing the fourth electrode 36, it is possible to prevent the black matrix 33 from being charged. Figure 22

[0081] The second linear electrode portion 34a can also extend in a second direction D2 intersecting the first direction D1 in plan view and overlap a portion of the black matrix 33 extending in the second direction D2. Further, it can be provided along the end portion in the second direction D2 of one pixel (the upper and lower ends of the pixel in the present embodiment). Figure 1

[0082] The second linear electrode portion 34a is preferably not overlapped with the above-described optical opening portion in plan view. Since the third electrode 34 has a portion not overlapped with the above-described optical opening portion, in the case of displaying in the common mode, a longitudinal electric field is difficult to act on the opening portion of the pixel, and thus it is possible to obtain high transmittance and high contrast.

[0083] The above-described gate wiring 1 can also extend in the second direction D2, that is, the extending direction of the second linear electrode portion 34a. The third electrode 34 can also overlap at least a portion of the gate wiring 1 in plan view. From the viewpoint of improving privacy performance, the width of the second linear electrode portion 34a can be wider than the width of the gate wiring 1.

[0084] The width of the second linear electrode portion 34a is preferably 5 μm or more. The upper limit of the width of the second linear electrode portion 34a is not particularly limited, and can be, for example, 50 μm, provided that it is not overlapped with the optical opening portion. The more preferable lower limit of the width of the second linear electrode portion 34a is 15 μm, and the more preferable upper limit is 40 μm. The width of the second linear electrode portion 34a is the electrode width in the direction orthogonal to the second direction D2.

[0085] The third electrode 34 can be formed of a transparent conductive material. As the above-described transparent conductive material, ITO, IZO, and the like can be given.

[0086] ​​The fourth electrode 36 is disposed between the black matrix 33 and the third electrode 34. The fourth electrode 36 functions as a shield electrode that shields an electric field generated between the third electrode 34 and the black matrix 33 and prevents the black matrix 33 from being charged, when a constant voltage is applied to the fourth electrode 36 and a voltage is applied to the third electrode 34. Therefore, by providing the fourth electrode 36, it is possible to prevent light leakage on the source wiring 2 due to the alignment direction of liquid crystal molecules deviating from the absorption axis of the polarizing plate in the black display of the privacy mode, and it is possible to improve the front contrast.

[0087] From the viewpoint of further improving the shielding effect, the area of the fourth electrode 36 is preferably larger than the area of the black matrix. In the first embodiment, a case where the fourth electrode 36 is a full-area electrode is exemplified. Further, the fourth electrode 36 preferably overlaps at least a part of the black matrix 33 and at least a part of the optical opening portion in plan view. As the material of the fourth electrode 36, for example, a transparent conductive material such as ITO, IZO, or the like can be exemplified.

[0088] It is preferable to dispose the second dielectric layer 35 between the third electrode 34 and the fourth electrode 36. As the second dielectric layer 35, a resin such as an acrylic resin, a polyimide resin, or the like can be used. The second dielectric layer 35 is, for example, a layer formed of a resin having light transmittance. The total light transmittance of the second dielectric layer 35 is preferably 80% or more. In the present specification, the total light transmittance refers to the total light transmittance measured based on JIS K7361-1. The components such as the color filter 32 possessed by the color filter substrate 30 are often made of an organic material, but when the color filter 32 or the like and the second dielectric layer 35 have a large thermal stress difference, cracks can occur in the third electrode 34 and / or the fourth electrode 36. Therefore, from the viewpoint of reducing the thermal stress difference, it is preferable to use the above-described resin as the second dielectric layer 35, to planarize the surface of the third electrode 34, and to shield the electric field.

[0089] When the liquid crystal panel 100A is observed from the front side, the color filter 32 is disposed in each pixel in a manner of overlapping the above-described optical opening portion. The color filter 32 includes, for example, a red color filter 32R, a green color filter 32G, and a blue color filter 32B. For example, the color filter 32 can also continuously form the same color color filter in the row direction or the column direction of the liquid crystal panel 100A. The color filter 32 is preferably a dielectric layer.

[0090] The black matrix 33 is disposed between a plurality of pixels. The black matrix 33 can be disposed between the above-described optical opening portions adjacent in the row direction or the column direction, or can be disposed around the optical opening portion in plan view. As the black matrix 33, a black matrix generally used in the field of liquid crystal display devices can be used, but it is preferably composed of a resin, and more preferably composed of a black resin. The specific resistance of the black matrix 33 is, for example, 1.0 x 1010 ~ 1.0 x 10 13 (Ω-cm).

[0091] The first dielectric layer 50 is arranged between the black matrix 33 and the third electrode 34. By arranging the first dielectric layer 50, the distance between the black matrix 33 and the third electrode 34 becomes farther, and thus the charging to the black matrix 33 caused by application of voltage to the third electrode 34 can be reduced.

[0092] The dielectric constant ε of the first dielectric layer 50 can be, for example, ε = 3 to 4. The thickness of the first dielectric layer 50 is preferably 0.5 μm or more and 4 μm or less. The first dielectric layer 50 is a layer different from the color filter 32, and is, for example, a layer formed of a resin having light transmittance. The total light transmittance of the first dielectric layer 50 is preferably 80% or more. As the first dielectric layer 50, a resin such as an acrylic resin, a polyimide resin, or the like can be used. If the first dielectric layer 50 is too thick, parallax crosstalk from inclination occurs, and sometimes the desired color cannot be obtained. Further, if the thickness of the first dielectric layer 50 is 4 μm or more, unevenness is easily generated on the surface of the first dielectric layer 50, and sometimes display unevenness occurs.

[0093] Although not shown, an alignment film can be arranged between the active matrix substrate 10 and the liquid crystal layer 20 and between the color filter substrate 30 and the liquid crystal layer 20, respectively. The alignment film controls the initial alignment azimuth of the liquid crystal molecules in a state where voltage is not applied. The alignment film is preferably a horizontal alignment film. The horizontal alignment film preferably changes the pretilt angle of the liquid crystal molecules with respect to the surface of the alignment film from 0° to 1° in the initial state (state where voltage is not applied to the liquid crystal layer).

[0094] Further, a first polarizing plate 61 and a second polarizing plate 62 can be arranged on the side of the active matrix substrate 10 opposite to the liquid crystal layer 20 and on the side of the color filter substrate 30 opposite to the liquid crystal layer 20, respectively. Preferably, the absorption axis 61A of the first polarizing plate 61 and the absorption axis 62A of the second polarizing plate 62 are orthogonal Nicol arranged in a manner that they are orthogonal to each other. In Figure 1 , the absorption axis 61A of the first polarizing plate 61 is in the 0°-180° azimuth, and the absorption axis 62A of the second polarizing plate 62 is in the 90°-270° azimuth. The first polarizing plate 61 and the second polarizing plate 62 are preferably linear polarizing plates.

[0095] Figure 4 is a liquid crystal display device in which the liquid crystal layer 20 is arranged between the active matrix substrate 10 and the color filter substrate 30. Figure 2A cross-sectional view of an example in which the third dielectric layer is provided on the liquid crystal panel is shown. The liquid crystal panel 100B can also have a third dielectric layer 51 between the third electrode 34 and the liquid crystal layer 20. The liquid crystal panel 100B has the same configuration as the liquid crystal panel 100A except for the point of having the third dielectric layer 51. The third dielectric layer 51 is a layer different from the alignment film, and the third dielectric layer 51 is preferably provided between the third electrode 34 and the alignment film. By providing the third dielectric layer 51, in the public mode, generation of an unnecessary vertical electric field generated between the third electrode 34 and the electrode on the active matrix substrate side can be suppressed. As a result, since the horizontal electric field drive can be performed without almost making the liquid crystal molecules stand, the transmittance at the time of white display on the front surface and the front contrast ratio at the time of display in the public mode can be improved.

[0096] The dielectric constant ε of the third dielectric layer 51 can be, for example, ε = 3 to 4. The thickness of the third dielectric layer 51 is preferably 0.5 μm or more and 4 μm or less. When the above thickness exceeds 4 μm, parallax color mixing can sometimes occur, and the display quality can be reduced. The third dielectric layer 51 can be formed of the same material as the first dielectric layer 50. The total light transmittance of the third dielectric layer 51 is preferably 80% or more.

[0097] The liquid crystal display device of the first embodiment can also have a backlight 300 on the back surface side (active matrix substrate 10 side) of the liquid crystal panel 100A, 100B. As the backlight 300, there is no particular limitation, and a backlight generally used in the field of liquid crystal display devices can be used. The backlight 300 can be either a transmissive type or a side light type. From the viewpoint of further improving the privacy in the privacy mode, as the backlight 300, a backlight provided with a light-shielding shutter described later can also be used.

[0098] The liquid crystal panel 100A, 100B of the first embodiment can also be an in-cell touch panel. In the case where the liquid crystal panel 100A, 100B is an in-cell touch panel, the active matrix substrate 10 can also have a touch panel wiring. The above touch panel wiring can be, for example, provided so as to overlap the source wiring 2 in the same degree of width as the source wiring 2 in plan view. Further, in cross-sectional view, it can also be provided between the first electrode 12 and the second electrode 14. In the first embodiment, the fourth electrode 36 is a full-surface electrode, but if the fourth electrode 36 is high in resistance, the signal-to-noise ratio (S / N ratio) can be sufficiently ensured, so the electrostatic capacitance between the finger and the touch panel wiring can be sensed. In addition, the resistance of the fourth electrode 36 is, for example, 1.0 x 10 6 ~1.0 x 10 8(Ω-cm), it can be said to be high resistance. The resistance of the fourth electrode 36 described above can be adjusted by the film formation method (sputtering method or the like) of the electrode material at the time of forming the fourth electrode 36.

[0099] <Second Embodiment>

[0100] The liquid crystal display device of the second embodiment has the same configuration as the first embodiment except that the third electrode has a third linear electrode portion. Figure 5A is a plan view of one pixel of the liquid crystal panel exemplified in the second embodiment. Figure 5B is a plan view of the fourth electrode shown in Figure 5A Figure 6 is a cross-sectional view of the X2-X2' line of Figure 5A

[0101] As shown in Figure 5A , the liquid crystal panel 100C of the second embodiment has a third linear electrode portion 34b that is configured so as to extend in the second direction D2 and overlap with the optical opening portion of the pixel in plan view. The third electrode 34 has the third linear electrode portion 34b, and thus it is possible to further suppress the contrast in the case of viewing from the left-right direction compared to the first embodiment while maintaining a high level of front contrast. The third linear electrode portion 34b can also be configured between a plurality of second linear electrode portions 34a configured at the ends in the second direction D2 of one pixel (the upper and lower ends of the pixel in Figure 1 ).

[0102] The third linear electrode portion 34b is preferably electrically connected to the second linear electrode portion 34a and is applied with the same voltage as the second linear electrode portion 34a. The width of the third linear electrode portion 34b is preferably narrower than the width of the second linear electrode portion 34a.

[0103] As shown in Figure 5A and Figure 6 , in the case of configuring one third linear electrode portion 34b with respect to one pixel, the third linear electrode portion 34b is preferably configured at the center of the optical opening portion of the pixel. The third linear electrode portion 34b can overlap with at least a portion of the optical opening portion. In the case of configuring one third linear electrode portion 34b, the width of the third linear electrode portion 34b is preferably 3 μm or more and 10 μm or less. The more preferable lower limit of the width of the third linear electrode portion 34b is 5 μm, and the more preferable upper limit is 7 μm.

[0104] As shown in Figure 5B ​​In the second embodiment, the fourth electrode 36 can also overlap the optical opening of the pixel with the third linear electrode portion 34b, as shown. Specifically, as with the first embodiment, the fourth electrode 36 can also be a flat plate-shaped electrode (full-area electrode) in which no slits or openings are provided at least in the region overlapping the optical opening of the pixel. Even if the fourth electrode 36 is a full-area electrode, as long as the fourth electrode 36 is high in resistance, the S / N ratio can be sufficiently ensured, and thus the liquid crystal panel 100C of the second embodiment and the liquid crystal panel 100D to be described later can also be configured as an in-cell touch panel, as with the first embodiment.

[0105] Figure 7 is a plan view schematically showing one pixel of another example of the second embodiment. Figure 8 is a cross-sectional view schematically showing the X3-X3' line of Figure 7 . The liquid crystal panel 100D can also be configured with a plurality of third linear electrode portions 34b at positions overlapping the optical openings of the pixels. Figure 7 and Figure 8 indicate an example in which three third linear electrode portions 34b are provided. By providing a plurality of third linear electrode portions 34b, the high front contrast ratio is maintained, and the contrast ratio in the case of viewing from the left-right direction (for example, when the liquid crystal panel is viewed at a polar angle of 45° from the 0° orientation or the 180° orientation) can be further suppressed compared to the case in which one third linear electrode portion 34b is provided.

[0106] In the case in which a plurality of third linear electrode portions 34b are provided, the width of the third linear electrode portion 34b is preferably narrower than the width of the second linear electrode portion 34a. The width of the third linear electrode portion 34b is preferably 3 μm or more and 12 μm or less. By setting the width of the third linear electrode portion 34b to the above range, the front contrast ratio in the privacy mode can be improved, and the polar angle 45° contrast ratio can be sufficiently suppressed. The more preferable lower limit of the width of the third linear electrode portion 34b is 5 μm, and the more preferable upper limit is 10 μm. From the viewpoint of being able to further improve the front contrast ratio in the public mode, it is more preferable that the width of the third linear electrode portion 34b be 10 μm. The width of the third linear electrode portion 34b is the electrode width in a direction orthogonal to the second direction D2.

[0107] In the case in which a plurality of third linear electrode portions 34b are provided, it is preferable that the plurality of third linear electrode portions 34b be provided at equal intervals. The distance between adjacent third linear electrode portions 34b is preferably 10 μm or more and 50 μm or less. The more preferable lower limit of the distance between adjacent third linear electrode portions 34b is 15 μm, and the more preferable upper limit is 40 μm.

[0108] Multiple third linear electrode sections 34b can be connected at the ends of the liquid crystal panel via a connecting portion, for example. Alternatively, multiple second linear electrode sections 34a, multiple third linear electrode sections 34b, and the aforementioned connecting portion can be combined to form a third electrode 34.

[0109] In the second embodiment, a third dielectric layer 51 may also be provided between the third electrode 34 and the liquid crystal layer 20. Figure 9 It means in Figure 8 The diagram shows a cross-sectional view of an example liquid crystal panel in which a third dielectric layer 51 is disposed. By distributing the third dielectric layer 51, the liquid crystal panel 100E can improve the contrast when displayed in common mode.

[0110] <Third Implementation Method>

[0111] The liquid crystal display device of the third embodiment has the same configuration as that of the first embodiment, except that the arrangement of the fourth electrode in the cross section is different. Figure 10 This is a cross-sectional schematic diagram of the liquid crystal panel illustrated in the third embodiment. Figure 10 Equivalent to Figure 1 A cross-sectional view at line X1-X1'. Due to the difference between the planar view and... Figure 1 Since they are the same, the explanation is omitted.

[0112] like Figure 10 As shown, in the liquid crystal panel 100F of the third embodiment, the color filter substrate 30 sequentially includes a second substrate 31, a black matrix 33, a fourth electrode 36, a color filter 32, a second dielectric layer 35, and a third electrode 34. In the third embodiment, by configuring the fourth electrode 36, charging of the black matrix 33 can also be prevented. Therefore, in the black display of privacy mode, light leakage can be prevented, and the front contrast can be improved. Furthermore, by configuring the fourth electrode 36 on the black matrix 33, the color filter 32 also insulates the third electrode 34 from the fourth electrode 36, except for the second dielectric layer 35. From the viewpoint of reducing the breakage of the third electrode 34, it is preferable to form the third electrode 34 after planarizing the second dielectric layer 35 on the color filter 32.

[0113] In the LCD panel 100F, the fourth electrode 36 can also be... Figure 5B The fourth electrode 36 is an entire surface electrode, as long as the fourth electrode 36 has high resistance, the S / N ratio can be sufficiently ensured. Therefore, the liquid crystal panel 100F of the third embodiment can also adopt an embedded touch panel in the same way as the first embodiment.

[0114] A third dielectric layer 51 can also be provided between the third electrode 34 and the liquid crystal layer 20. By providing the third dielectric layer 51, the contrast ratio when displaying in the common mode can be improved.

[0115] <Fourth Embodiment>

[0116] The liquid crystal display device of the fourth embodiment has the same configuration as the second embodiment except that the fourth electrode is provided with an opening. Figure 11A is a plan view of one pixel of the liquid crystal panel exemplified in the fourth embodiment. Figure 11B is a plan view of the fourth electrode shown in Figure 11A Figure 12 is a cross-sectional view at the X4-X4' line of Figure 11A

[0117] In the fourth embodiment, the third electrode 34 includes the third linear electrode portion 34b, and the fourth electrode 36 is provided with an opening 36a at a position overlapping the third linear electrode portion 34b in plan view. Regarding the fourth electrode 36, by providing the opening 36a at a position overlapping the third linear electrode portion 34b in plan view, the transmittance can be improved.

[0118] The number of openings 36a provided in one pixel is not particularly limited and can be the same as the number of third linear electrode portions 34b provided in one pixel. In the case where one third linear electrode portion 34b is provided in one pixel, one opening 36a can also be provided at a position overlapping the optical opening portion.

[0119] The shape of the opening 36a is not particularly limited and can be a rectangular shape overlapping the third linear electrode portion 34b in plan view. Although not shown, the opening 36a can also be surrounded by the electrode portion of the fourth electrode 36.

[0120] Figure 13A is a plan view of one pixel of another example of the fourth embodiment. Figure 13B is a plan view of the fourth electrode shown in Figure 13A Figure 14 is a cross-sectional view at the X5-X5' line of Figure 13A In the case where three third linear electrode portions 34b are provided in one pixel, three openings 36a can also be provided at positions overlapping the optical opening portion. The fourth electrode 36 can be provided between adjacent third linear electrode portions 34b in plan view.

[0121] ​​​The liquid crystal panel 100G, 100H of the fourth embodiment can also be an in-cell touch panel. By providing the opening 36a, charging of the black matrix 33 can be prevented, and the S / N ratio can be improved compared to the first embodiment, and the electrostatic capacitance between a finger and a touch panel wiring can be ensured.

[0122] <5th Embodiment>

[0123] As a fifth embodiment, a control circuit of a liquid crystal display device, a display method, and a veil-view display are described below.

[0124] (Control Circuit)

[0125] The control circuit can switch between a first display mode in which a first image that can be observed from a narrow viewing angle range including a normal direction of a liquid crystal panel is displayed, and a second display mode in which the first image can be observed from a wide viewing angle range including the narrow viewing angle range.

[0126] In this specification, the first display mode is referred to as a privacy mode, and the second display mode is referred to as a public mode. In the narrow viewing angle range, when the liquid crystal panel is observed at a certain polar angle from the left-right direction (0° orientation or 180° orientation), the contrast is preferably lower than 20, and more preferably 10 or lower. The polar angle is, for example, preferably 60° or higher, more preferably 45° or higher, and further preferably 30° or higher, in the case where a direction perpendicular to the surface of the liquid crystal panel is set as a polar angle 0°, and a direction horizontal to the surface of the liquid crystal panel is set as a polar angle 90°. The wide viewing angle range refers to a range of polar angles that is larger than the polar angle of the narrow viewing angle range.

[0127] Figure 15 is a block diagram schematically showing a display method of the first display mode and the second display mode in the fifth embodiment. As shown in Figure 15 The liquid crystal display device of the embodiment has a liquid crystal panel and a control circuit 200. As the liquid crystal panel, the liquid crystal panels 100A to 100H described in the first to fourth embodiments can be used.

[0128] The liquid crystal panel can also have a first electrode drive circuit 101 that applies a voltage to the first electrode 12, a second electrode drive circuit 102 that applies a voltage to the second electrode 14, and a third electrode drive circuit 103 that applies a voltage to the third electrode 34. The control circuit 200 can also have an image signal synthesis circuit 201, a display mode selection circuit 202, and a third electrode voltage switching circuit 203.

[0129] The control circuit 200 controls the application of a drive voltage to the third electrode 34 in the first display mode (privacy mode) and controls the application of a constant voltage to the third electrode 34 in the second display mode (public mode). The constant voltage is an alternating voltage that can be set to output a constant voltage regardless of the magnitude of the impedance of the third electrode 34. The constant voltage is regarded as a common voltage for the third electrode 34, and determines the value of the voltage (alternating voltage) applied to the first electrode 12 and the second electrode 14. When the constant voltage is regarded as a common voltage Vcom = 0 V, for example, the Vcom voltage is applied to the first electrode 12, and an alternating voltage of Vcom ± α [V] (α is a voltage value of 0 V or more, and the frequency is 60 Hz) is applied to the second electrode 14, thereby generating edge electric fields in which the direction of the electric field alternates with a period of 60 Hz between the first electrode 12 and the second electrode 14.

[0130] In the privacy mode of the liquid crystal panel, the drive voltage applied to the third electrode 34 is an alternating voltage having a larger effective value than the constant voltage. By applying an alternating voltage to the third electrode 34, a longitudinal electric field can be formed between the first electrode 12 (or the second electrode 14) to which the common voltage is applied. The drive voltage can be, for example, an alternating voltage having a larger effective value than the constant voltage by 3 to 7.5 V. Furthermore, from the viewpoint of suppressing the phenomenon of afterimage (burn-in) of a residual display image in the privacy mode, it is preferable that the drive voltage applied to the third electrode 34 be an alternating voltage of Vcom ± α [V] (α is a voltage value of 0 V or more, and the frequency is 120 Hz). This means that the frequency fl [Hz] of the drive voltage of the second electrode 14 and the frequency f2 [Hz] of the drive voltage of the third electrode 34 have a relationship of 2 x fl = f2.

[0131] A constant voltage is applied to the fourth electrode 36. The constant voltage applied to the fourth electrode 36 is an alternating voltage that can be set to output a certain voltage regardless of the magnitude of the impedance of the fourth electrode 36. The constant voltage applied to the fourth electrode 36 is preferably the same common voltage Vcom as the constant voltage applied to the third electrode 34 in the privacy mode. The fourth electrode 36 can be electrically connected to the common voltage Vcom on the active matrix substrate 10 side, for example.

[0132] The image signal synthesis circuit 201 is input, for example, an original image signal 211 for displaying a desired image, and outputs an image signal 212 corresponding to the input original image signal 211 to the first electrode drive circuit 101 and the second electrode drive circuit 102.

[0133] The display mode selection circuit 202 is inputted with a display mode switching signal 213 which switches between the first display mode and the second display mode. In the case where the first display mode is selected, the display mode selection circuit 202 applies a first display mode selection signal 214 outputted from the voltage switching circuit 203 to the third electrode. In the case where the second display mode is selected, the display mode selection circuit 202 applies a second display mode selection signal 215 outputted from the voltage switching circuit 203 to the third electrode.

[0134] The third electrode application voltage switching circuit 203 inputs a driving voltage signal 216 or a constant voltage signal 217 to the third electrode drive circuit 103 in accordance with the display mode selection signal inputted, and switches between the application of the driving voltage to the third electrode 34 and the application of the constant voltage. When the first display mode selection signal 214 is inputted from the display mode selection circuit 202, the third electrode application voltage switching circuit 203 outputs the driving voltage signal 216 to the third electrode drive circuit 103, and applies a prescribed alternating voltage to the third electrode 34. When the second display mode selection signal 215 is inputted from the display mode selection circuit 202, the third electrode application voltage switching circuit 203 outputs the constant voltage signal 217 to the third electrode drive circuit 103, and applies a prescribed constant voltage to the third electrode 34.

[0135] <Display method>

[0136] Next, one example of the display method in the first display mode and the second display mode will be described. First, in a state where no voltage is applied to the liquid crystal layer described above, the liquid crystal molecules are horizontally oriented with respect to the active matrix substrate 10. In the present specification, "horizontal" means that the tilt angle (including the pretilt angle) of the liquid crystal molecules is 0° to 5°, preferably 0° to 3°, and more preferably 0° to 1° with respect to the surface of the active matrix substrate 10 or the color filter substrate 30. The tilt angle of the liquid crystal molecules means the angle at which the long axis of the liquid crystal molecules is inclined with respect to the surface of the active matrix substrate 10.

[0137] In the case of black display in the public mode, the control circuit 200 applies a prescribed alternating voltage as a constant voltage to the third electrode 34. The control circuit 200 controls the second electrode 14, the first electrode 12, and the fourth electrode 36 to apply a common voltage of 0 V to the constant voltage. Alternatively, the common voltage applied to the second electrode 14, the first electrode 12, and the fourth electrode 36 can be the same as the constant voltage or can be a voltage less than the threshold value of the liquid crystal molecules. This state is also referred to as a no-voltage application state. In the no-voltage application state, no electric field for driving the liquid crystal molecules is generated in the liquid crystal layer 20, and thus the liquid crystal molecules are oriented in the initial orientation direction. Since the orientation direction of the liquid crystal molecules in the plane of the liquid crystal layer 20 does not change, the liquid crystal panel does not transmit light from the back surface and becomes black display. Note that black display refers to a display state in which the lowest luminance (0 gray scale) is obtained, and white display refers to a display state in which the highest luminance (255 gray scale) is obtained. The initial orientation direction is preferably parallel to the active matrix substrate 10 and parallel to the absorption axis 61A of the first polarizing plate 61 or the absorption axis 62A of the second polarizing plate 62 in plan view.

[0138] In the case of white display in the public mode, for example, the control circuit controls the third electrode 34 to which a constant voltage is applied, either of the first electrode 12 and the second electrode 14, and the fourth electrode 36 to which a constant voltage (common voltage) is applied, and the other of the first electrode 12 and the second electrode 14 to which an alternating voltage having a different effective value from the common voltage is applied. An edge electric field is formed between the first electrode 12 and the second electrode 14, and on the other hand, unlike the privacy mode described later, an electric field in the thickness direction of the liquid crystal layer 20 is small. Thus, the liquid crystal molecules are oriented in parallel to the active matrix substrate 10 in the electric field formed between the first electrode 12 and the second electrode 14, and the orientation direction is changed. The liquid crystal molecules rotate in the plane of the liquid crystal layer 20 from the initial orientation direction, and thus the long axis direction of the liquid crystal molecules forms an angle with the absorption axis 61A of the first polarizing plate and the absorption axis 62A of the second polarizing plate, and light from the back surface of the liquid crystal panel is transmitted to perform white display.

[0139] In the case of black display in the privacy mode, the control circuit controls the third electrode to which a driving voltage having a different effective value from the constant voltage is applied, and the second electrode 14, the first electrode 12, and the fourth electrode 36 to which a constant voltage (common voltage) is applied. An inclined electric field is formed between the third electrode 34 and the first electrode 12 and the second electrode 14. The liquid crystal molecules form an angle with the active matrix substrate 10 by the inclined electric field.

[0140] Since the orientation direction of the liquid crystal molecules does not change in the in-plane direction of the liquid crystal layer 20, the liquid crystal panel does not transmit light from the back surface, on the other hand, the liquid crystal molecules are angled with respect to the active matrix substrate, and thus, when the liquid crystal panel is observed from a wide viewing angle range, a display that is whiter than a black display observed from a narrow viewing angle range is observed.

[0141] In the case where white display is set in the privacy mode, the control circuit 200 performs control such that, in a state where the driving voltage is applied to the third electrode 34, a constant voltage (common voltage) is applied to either one of the first electrode 12 and the second electrode 14 and the fourth electrode 36, and an alternating voltage having an effective value different from the common voltage is applied to the other one of the first electrode 12 and the second electrode 14. Preferably, the driving voltage applied to the third electrode 34 has a different effective value from the alternating voltage applied to the first electrode 12 or the second electrode 14, and more preferably, the effective value is greater than the alternating voltage applied to the first electrode 12 and the second electrode 14.

[0142] Further, the driving voltage applied to the third electrode 34 can have a different frequency from the alternating voltage applied to the first electrode 12 or the second electrode 14, and the frequency of the driving voltage can be higher than the frequency of the alternating voltage applied to the first electrode 12 or the second electrode 14. The frequency of the driving voltage can be 60 Hz or 120 Hz, and the frequency of the alternating voltage applied to the first electrode 12 or the second electrode 14 can be 60 Hz. By setting the frequency of the driving voltage to 120 Hz, flicker can be reduced.

[0143] An edge electric field is formed between the first electrode 12 and the second electrode 14, and a tilt electric field is formed with respect to the thickness direction of the liquid crystal layer 20 between the third electrode 34 and the first electrode 12 or between the third electrode 34 and the second electrode 14. As a result, an electric field that combines the above-described edge electric field and the above-described tilt electric field is formed in the liquid crystal layer 20, and thus the liquid crystal molecules are oriented while changing the potential with respect to the active matrix substrate 10 by the electric field formed between the first electrode 12, the second electrode 14, and the third electrode 34, thereby performing white display. Since the liquid crystal molecules are angled with respect to the active matrix substrate, the first image can be observed from a narrow viewing angle range, on the other hand, when the liquid crystal panel is observed from a wide viewing angle range, an image change in which the contrast becomes extremely low or the like is obtained, and thus it is difficult to observe the above-described first image.

[0144] In the case of display in the privacy mode, as described above, the gray scale display is performed while applying a voltage to the third electrode 34. In the conventional liquid crystal display device, when a voltage is applied to the electrode provided on the color filter substrate (the third electrode in the present embodiment), the black matrix provided on the color filter substrate is charged (electrified), and an electric field that is not parallel or orthogonal to the absorption axis of the polarizing plate in plan view can be formed between the electrified black matrix and the electrode on the active matrix substrate side. If an electric field that is not parallel or orthogonal to the absorption axis of the polarizing plate is generated, the long axis (director) of the liquid crystal molecules deviates from the absorption axis of the polarizing plate, and the alignment of the liquid crystal molecules is disturbed, and light leakage (black floating) can occur when viewed from the front in black display. The front contrast ratio in the privacy mode can sometimes be reduced. In the first to fourth embodiments, by providing the fourth electrode 36 between the third electrode 34 and the black matrix 33, and applying a constant voltage to the fourth electrode 36, the electric field generated between the third electrode 34 and the black matrix 33 is shielded, the electrification of the black matrix is prevented, and the occurrence of the above-described light leakage can be prevented.

[0145] The white display in the privacy mode and the white display in the public mode described above can be switched by applying a voltage to the third electrode. Similarly, the black display in the privacy mode and the black display in the public mode can be switched by applying a voltage to the third electrode. The same applies to the intermediate gray scale display.

[0146] In the liquid crystal display device of the embodiment, as described above, by switching from the second display mode (public mode) to the first display mode (privacy mode), high privacy can be obtained when viewed from the left-right direction of the liquid crystal panel. In addition, the above-described left-right direction refers to the case where the right-hand direction of the liquid crystal panel on which an image is desired to be displayed is set to 0°, and the angle is increased in the counterclockwise direction, and is referred to as the 0° orientation and the 180° orientation.

[0147] <Viewing angle control display>

[0148] In addition to the above-described switching of the display mode, it is also possible to be combined with the viewing angle control function described later. In addition, the viewing angle control function refers to a function of displaying a specific viewing angle control pattern by software. For example, it is also possible to display the viewing angle control pattern by driving the above-described control circuit by software. Hereinafter, the case where the viewing angle control pattern is displayed by the viewing angle control function will be described. Figures 16-18 One example of a method of displaying an image by the viewing angle control function will be described. In the case of displaying a color image, the viewing angle control pattern is displayed in a color. Figure 16 In the case of displaying a color image, the viewing angle control pattern is displayed in a color. Figure 17 In the case of displaying a color image, the viewing angle control pattern is displayed in a color. Figure 1 is a plan view schematically showing the first pixel 70 and the second pixel 71 shown in FIGS. 1 to 3. Figure 16 is a plan view schematically showing one example of a display unit that the liquid crystal panel has. Figure 17 is a plan view schematically showing one example of a color element in the case of color display by the viewing angle control function. Figure 18is a block diagram schematically showing a display method in a case where the viewing angle control pattern in the fifth embodiment is displayed.

[0149] As shown in Figure 16 , the liquid crystal panels 100A to 100H (hereinafter, also simply referred to as liquid crystal panels) have a plurality of display units 72 that display an image by a viewing angle control function. The display units 72 are arranged adjacent to each other, and include a pair of pixels composed of a first pixel 70 selected from an odd-numbered row and a second pixel 71 selected from an even-numbered row. As shown in Figure 1 , the first pixel 70 and the second pixel 71 can be captured as one pixel, respectively, or as shown in Figure 17 , a combination of a first red pixel 70R, a first green pixel 70G, and a first blue pixel 70B can be captured as the first pixel 70, and a combination of a second red pixel 71R, a second green pixel 71G, and a second blue pixel 71B can be captured as the second pixel 71. In addition, in a case where color display is performed by a normal display method, color display can be performed by independently driving each pixel including red, green, and blue. In a case where normal color display is performed, display can be performed at a resolution twice as high as in a case where color display is performed by using the viewing angle control function.

[0150] In a case where color display is performed, the above-described liquid crystal panel preferably includes a red display unit 72R including the first red pixel 70R and the second red pixel 71R, a green display unit 72G including the first green pixel 70G and the second green pixel 71G, and a blue display unit 72B including the first blue pixel 70B and the second blue pixel 71B. The color element 73 can also include the red display unit 72R, the green display unit 72G, and the blue display unit 72B. The first red pixel 70R and the second red pixel 71R respectively overlap the red color filter 32R at the optical opening. The first green pixel 70G and the second green pixel 71G respectively overlap the green color filter 32G at the optical opening. The first blue pixel 70B and the second blue pixel 71B respectively overlap the blue color filter 32B at the optical opening.

[0151] As a method for displaying images using viewing angle control, for example, when the brightness data value of the original image to be displayed as the first image is set to Data1, Data1 is divided into two equal data values, Data2 and Data3. The data value of Data1 + Data2 is input to either the first pixel 70 or the second pixel 71, and the data value of Data1 - Data3 is input to the other. When viewing the liquid crystal panel from a narrow viewing angle, the brightness of the first pixel 70 and the brightness of the second pixel 71 are spatially averaged, and the brightness of the original image is visually confirmed. On the other hand, when viewing from a wide viewing angle, the brightness of Data1 + Data2 or Data1 - Data3 is visually confirmed.

[0152] The following uses Figure 18 This describes a display method for displaying a viewing angle control pattern. In the first display mode, the control circuit 200 inputs different image signals to the first pixel and the second pixel in a manner that allows viewing a second image different from the first image from a wide viewing angle. This display method is also referred to as a viewing angle control function. Since the display based on the viewing angle control function, combined with the first display mode (privacy mode), can further enhance privacy, it is preferable that when the first display mode selection signal 214 is input from the display mode selection circuit 202, the database 205 outputs the viewing angle control pattern image signal 220 to the image signal synthesis circuit 201.

[0153] like Figure 18 As shown, the control circuit 200 may also have a database 205 storing information related to the viewing angle control pattern. When a visual control display switching signal 219 is input, the database 205 outputs the viewing angle control pattern image signal 220 to the image signal synthesis circuit 201. The image signal synthesis circuit 201 outputs an image signal 212 to the first electrode driving circuit 101 and the second electrode driving circuit 102. The image signal 212 is an image signal synthesized by combining the original image signal 211 and the viewing angle control pattern image signal 220.

[0154] For example, in a case where a common voltage is applied to the second electrode 14 by the second electrode drive circuit 102, for the first electrode 12, different voltages are applied to the first electrode 12 corresponding to the first image pixel 70 and the second image pixel 71, respectively, in a manner that the above-described second image is observed from a wide viewing angle range, by the first electrode drive circuit 101. In this case, it is preferable that the first electrode 12 be provided per pixel. On the other hand, in a case where a common voltage is applied to the first electrode 12 by the first electrode drive circuit 101, for the second electrode 14, different voltages are applied to the second electrode 14 corresponding to the first image pixel 70 and the second image pixel 71, respectively, in a manner that the above-described second image is observed from a wide viewing angle range, by the second electrode drive circuit 102.

[0155] The above-described second image is preferably a viewing angle control pattern. The above-described viewing angle control pattern is a display image that is displayed in superposition with the above-described first image and is difficult to visually recognize the above-described first image. By displaying the viewing angle control pattern, privacy can be further improved. As the above-described viewing angle control pattern, there is no particular limitation, and a geometric pattern such as a stripe pattern, a checkered pattern, a character, an image, or the like can be displayed.

[0156] <Sixth Embodiment>

[0157] The liquid crystal display device of the sixth embodiment has a backlight on the back of the above-described liquid crystal panel, the backlight has a light source and a light-shielding shutter arranged on the liquid crystal panel side of the light source, and the control circuit controls in a manner that the brightness of the backlight in the above-described first display mode is lower than the brightness of the backlight in the above-described second display mode. As the liquid crystal panel, any one of the liquid crystal panels 100A to 100H exemplified in the first to fourth embodiments can be used.

[0158] In the sixth embodiment, as the backlight, a backlight having a light source and a light-shielding shutter arranged on the liquid crystal panel side of the light source is used. By using a backlight having a light-shielding shutter, the brightness in the normal direction can be relatively improved, and the directivity of the backlight can be improved. The backlight having the above-described light-shielding shutter can use a publicly known backlight, or a backlight disclosed in, for example, Patent Literature 3 can be used.

[0159] Figure 19 is a schematic exploded perspective view that schematically shows a backlight having a light-shielding shutter used in the sixth embodiment. The backlight having the above-described light-shielding shutter can be an edge light type backlight, for example, as shown in Figure 19As shown, the light guide plate 310 and the light source 311 disposed on the side of the light guide plate 310 can be provided, and a light-shielding blind 312 can be provided on the front side (liquid crystal panel side) of the light guide plate 310. A reflective sheet 313 can be disposed on the back of the light guide plate 310, and a prism sheet 314, a diffusion sheet 315, or the like can be disposed between the light guide plate 310 and the light-shielding blind 312. The light source 311 can be disposed on at least one of the opposite sides of the light guide plate 310, but can be disposed on both sides. Figure 17 As shown, the light source 311 is disposed along the 0°-180° orientation of the liquid crystal panel, but can be disposed along the 90°-270° orientation of the liquid crystal panel.

[0160] The light-shielding blind 312 preferably shields light emitted from the light guide plate according to the incident angle. For example, as the light-shielding blind, a light-shielding blind in which a light-transmitting layer 312a that transmits light and a light-absorbing layer 312b that absorbs light are alternately arranged in a specific period as disclosed in Patent Document 3 can be exemplified. The period in which the light-transmitting layer 312a and the light-absorbing layer 312b are arranged can be, for example, 100 μm to 150 μm. The light-transmitting layer 312a and the light-absorbing layer 312b can be arranged in a linear shape in plan view, and the extending direction of the light-transmitting layer 312a and the light-absorbing layer 312b is preferably at an angle of 0 to 10° with respect to the 90°-270° orientation of the liquid crystal panel, and can be parallel to the 90°-270° orientation (the angle is 0°). The light-transmitting layer 312a can be formed of a resin having light-transmitting properties, and the light-absorbing layer 312b can be formed of a black pigment or a resin containing a dye. The total light transmittance of the light-absorbing layer 312b is preferably, for example, 5% or less, and the total light transmittance of the light-transmitting layer 312a is preferably 80% or more.

[0161] The liquid crystal display device of the sixth embodiment can more effectively improve privacy in the privacy mode by coordinating the luminance of the backlight with the display mode. Figure 20 is a block diagram schematically showing a display method in the first display mode and the second display mode in the sixth embodiment. Figure 21 is a block diagram schematically showing a display method in a case where the viewing angle control pattern is displayed in the sixth embodiment.

[0162] The control circuit 200 controls so that the luminance of the backlight 300 in the above-described first display mode is lower than the luminance of the backlight 300 in the above-described second display mode. As shown in Figure 20 and Figure 21 The control circuit 200 can further include a backlight luminance modulation circuit 204 as shown. Further, the backlight 300 can include a backlight drive circuit 301.

[0163] When a first display mode selection signal 214 is input from the display mode selection circuit 202, the brightness modulation circuit 204 outputs a brightness modulation signal 218 to the backlight driving circuit 301, adjusting the brightness of the backlight 300 to decrease. When a second display mode selection signal 215 is input from the display mode selection circuit 202, the brightness modulation circuit 204 outputs the brightness modulation signal 218 to the backlight driving circuit 301, adjusting the brightness of the backlight 300 to increase.

[0164] The brightness of the backlight 300 can also be adjusted so that the brightness of the LCD panel when viewed from the normal direction is white, for example, 100-300 nits in the first display mode and 300-500 nits in the second display mode.

[0165] [Example]

[0166] The following examples and comparative examples illustrate the effects of the present invention, but the present invention is not limited to these examples. In the following examples and comparative examples, the voltage applied to the third electrode is set as a relative voltage (Vc).

[0167]

[0168] For Examples 1-3 and Comparative Example 1 below, it was confirmed whether switching between privacy mode and public mode was possible. Furthermore, by simulating light leakage, it was confirmed whether charging to the black matrix was suppressed.

[0169] (Example 1)

[0170] Example 1 is a specific example of the first embodiment, having the same characteristics as... Figures 1-3 The liquid crystal panel 100A shown has the same configuration. The active matrix substrate 10 has an FFS-type electrode configuration, and the first electrode 12 is a full-surface electrode without an opening. The second electrode 14 is arranged per pixel, having two first linear electrode portions 14a with a width of 2.5 μm, and an opening 14b with a width of 3.5 μm between the first linear electrode portions 14a. The liquid crystal molecules are positive liquid crystal materials. Regarding the color filter substrate 30, the thickness of the color filter is 2.3 μm, the thickness of the second dielectric layer 35 is 1.3 μm, and the thickness of the first dielectric layer 50 is 2 μm. The angle θ1 formed by the extension direction (first direction D1) of the first linear electrode portion 14a and the extension direction (second direction D2) of the second linear electrode portion 34a of the third electrode is 80°. The third electrode 34 has a second linear electrode portion 34a with a width of 40 μm. The fourth electrode 36 is a full-surface electrode without an opening.

[0171] ITO can be used as the first electrode 12, second electrode 14, third electrode 34, and fourth electrode 36. For example, silicon oxide can be used as the first insulating layer 13, and acrylic resin can be used as the second dielectric layer 35 and the first dielectric layer 50. The black matrix can be made of black resin with a resistivity of 1.0 × 10⁻⁶. 10 ~1.0×10 13 A black matrix of (Ω·cm).

[0172] (Example 2)

[0173] Example 2 has the same structure as Example 1, except that the thickness of the second dielectric layer 35 in Example 1 is changed to 4 μm.

[0174] (Example 3)

[0175] Example 3 is a specific example of the third embodiment, having the same characteristics as... Figure 10 The liquid crystal panel 100F shown has the same structure. Regarding the color filter substrate, Embodiment 3 has the same structure as Embodiment 1, except that a fourth electrode 36 is disposed between the black matrix 33 and the color filter. The thickness of the color filter is 2.3 μm, the thickness of the second dielectric layer 35 is 1.3 μm, and the thickness of the third dielectric layer 51 is 2 μm. The third dielectric layer 51 can use the same material as the first dielectric layer 50.

[0176] (Comparative Example 1)

[0177] Figure 22 This is a cross-sectional schematic diagram of the LCD panel in Comparative Example 1. For example... Figure 22 As shown, in the liquid crystal panel 1100A of Comparative Example 1, the color filter substrate 30 sequentially includes a second substrate 31, a black matrix 33, a color filter 32 (32G), a first dielectric layer 50, a third electrode 34 (34a), and a third dielectric layer 51. The liquid crystal panel 1100A of Comparative Example 1 does not have an electrode corresponding to the fourth electrode of Example 1 between the black matrix and the third electrode. The shape of the third electrode 34 (34a) is the same as that of Example 1.

[0178] Regarding Examples 1-3 and Comparative Example 1, the relative voltage Vc applied to the third electrode was varied from 0 to 10V to simulate frontal contrast and 45° polar angle contrast. The frontal contrast and 45° polar angle contrast were calculated using the following method: For black display, the first, second, and fourth electrodes were set to a common voltage Vcom = 0V. For white display, the first electrode was set to 6.5V (AC), and the second electrode to 0V.

[0179] The luminance at the time of black display (0 gray scale) and the luminance at the time of white display (255 gray scale) were measured with respect to the case where the liquid crystal panel was observed from the normal direction (front surface) and the case where the liquid crystal panel was observed at a polar angle of 45°, respectively, and the contrast ratio in the case of observation from the front surface (front surface contrast ratio) and the contrast ratio in the case of observation of the liquid crystal panel from the 0° direction or the 180° direction at a polar angle of 45° (polar angle 45° contrast ratio) were calculated by the following formula (1). The measurement of the luminance was performed using "SR-ULIR" manufactured by Topcon Technohouse Co., Ltd.

[0180] CR = Luminance at the time of white display (255 gray scale) / Luminance at the time of black display (0 gray scale) (1)

[0181] The transmittance from the front surface of one pixel at the time of black display in the privacy mode was simulated. The above simulation was performed using an LCD host 3D (manufactured by Synaptics Inc.). The first electrode, the second electrode, and the fourth electrode were set to a common voltage Vcom = 0 V, and the relative voltage Vc applied to the third electrode was 10 V. In the simulation chart, the darker the color, the lower the transmittance, and the whiter the portion, the higher the transmittance.

[0182] Figure 23 is a graph of the contrast ratio and the simulation result of the transmittance of one pixel of Comparative Example 1. According to the simulation result of Figure 23 , in Comparative Example 1, at the time of a relative voltage of 10 V, light leakage was confirmed in a wide range in a manner of surrounding the pixel. As a result, as shown in the graph of Figure 23 , it was found that the front surface contrast ratio decreased if the relative voltage was increased. In the relative voltage of 10 V, it was considered that the difference between the front surface contrast ratio and the polar angle 45° contrast ratio was small, and it was difficult to achieve the privacy mode. As shown in Figure 22 , when a voltage is applied to the third electrode 34 (34a), an electric field (arrow in Figure 22 ) is generated between the third electrode 34 and the black matrix 33, and the black matrix 33 is charged.

[0183] Figure 24 is a graph of the contrast ratio and the simulation result of the transmittance of one pixel of Example 1. Figure 25 is a graph of the contrast ratio and the simulation result of the transmittance of one pixel of Example 2. Figure 26 is a graph of the contrast ratio and the simulation result of the transmittance of one pixel of Example 3. Figures 24-26 The simulation result of the transmittance of

[0184] Figures 24-26As shown in the graphs, in Examples 1-3, even with an increased relative voltage, the decrease in frontal contrast can be suppressed, and even at a relative voltage of 10V, the difference between the frontal contrast and the contrast at a 45° polar angle can be adequately ensured. Therefore, it can be confirmed that Examples 1-3 can achieve switching between privacy mode and public mode. Moreover, since light leakage can be suppressed, a high frontal contrast is obtained.

[0185] Comparing the graphs of Examples 1 and 2, Example 2 confirms that, when viewed from a polar angle of 45°, by maintaining the same contrast as in Example 1 while simultaneously increasing the thickness of the third dielectric layer, a high frontal contrast can be maintained. Furthermore, in Example 3, the distance between the third and fourth electrodes is the longest, reducing the influence of the edge electric field between them. Therefore, compared to Examples 1 and 2, it is confirmed that the frontal contrast is maintained at a high level, and the shielding effect is high.

[0186] <Comparison of contrast in privacy mode>

[0187] Hereinafter, simulations were performed on Examples 1, 4, 5 and Comparative Example 2. In privacy mode, the contrast ratio (front contrast ratio) when the liquid crystal panel is viewed from the normal direction was compared with the contrast ratio (45° polar angle contrast ratio) when the liquid crystal panel is viewed from the 0° or 180° position at a polar angle of 45°.

[0188] (Example 4)

[0189] Example 4 is a specific example of the second embodiment, having the same characteristics as... Figure 5A , Figure 5B and Figure 6 The liquid crystal panel 100C shown has the same configuration. The third electrode 34 has the same configuration as in Embodiment 1, except that it has a third linear electrode portion 34b in each pixel. The width of the third linear electrode portion 34b is 10 μm.

[0190] (Example 5)

[0191] Example 5 is a specific example of the second embodiment, having the same characteristics as... Figure 7 and Figure 8 The liquid crystal panel 100D shown has the same configuration. The third electrode 34 has the same configuration as in Embodiment 1, except that it has three third linear electrode portions 34b per pixel. The widths of the three third linear electrode portions 34b are each 5 μm.

[0192] (Comparative Example 2)

[0193] Figure 27 is a cross-sectional schematic diagram of the liquid crystal panel of Comparative Example 2. Figure 27B for Figure 27AA plan view of the third electrode is shown. The liquid crystal panel 1100B of Comparative Example 2 has the same configuration as that of Example 5 except that the shape of the electrode 1036 disposed between the black matrix 33 and the third electrode 34 (34a, 34b) is different. The fourth electrode 36 of Example 5 is not provided with Figure 5B The entire electrode having the opening shown is shown. On the other hand, as shown in Figure 27B The electrode 1036 of Comparative Example 2 is different from the black matrix 33 in that the planar shape is the same shape.

[0194] With respect to Examples 1, 4, 5, and Comparative Example 2, black display in privacy mode was set by setting the first electrode, the second electrode, and the fourth electrode to a common voltage Vcom = (0 V) and setting the relative voltage to 10 V (AC). Further, white display in privacy mode was set by setting the first electrode to 6.5 V (AC), setting the second electrode and the fourth electrode to 0 V, and setting the relative voltage to 10 V (AC).

[0195] Figure 28 is a graph comparing the contrast ratios of Examples 1, 4, 5, and Comparative Example 2. As shown in Figure 28 In any one of Examples 1, 4, 5, a high front contrast ratio was obtained. Further, the contrast ratio at a polar angle of 45° was sufficiently suppressed with respect to the front contrast ratio, and it was confirmed that privacy mode could be achieved. Furthermore, in the order of Example 1 in which the third linear electrode portion was not provided, Example 4 in which one third linear electrode portion was provided, and Example 5 in which three third linear electrode portions were provided, it was confirmed that the value of the contrast ratio at a polar angle of 45° became lower, and in the order of Example 1, Example 4, and Example 5, privacy became higher.

[0196] On the other hand, in Comparative Example 2, when the relative voltage was set to 10 V, the front contrast ratio was lower than that of Examples 1, 4, 5. In Comparative Example 2, since the shielding effect of the electrode 1036 equivalent to the fourth electrode was not sufficiently exerted, it is considered that the black matrix was charged, light leakage occurred at the time of black display in privacy mode, and the front contrast ratio decreased.

[0197] Explanation of Reference Numerals

[0198] 1: Gate wire

[0199] 2: Source wire

[0200] 3: TFT

[0201] 10: Active matrix substrate

[0202] 11: First substrate

[0203] 12: First electrode

[0204] 13: first insulating layer

[0205] 14: second electrode

[0206] 14a: first linear electrode portion

[0207] 14b: opening

[0208] 20: liquid crystal layer

[0209] 30: color filter substrate

[0210] 31: second substrate

[0211] 32: color filter

[0212] 32B: blue color filter

[0213] 32G: green color filter

[0214] 32R: red color filter

[0215] 33: black matrix

[0216] 34: third electrode

[0217] 34a: second linear electrode portion

[0218] 34b: third linear electrode portion

[0219] 35: second dielectric layer

[0220] 36: fourth electrode

[0221] 36a: opening

[0222] 50: first dielectric layer

[0223] 51: third dielectric layer

[0224] 61: first polarizing plate

[0225] 61A: absorption axis of first polarizing plate

[0226] 62: second polarizing plate

[0227] 62A: absorption axis of second polarizing plate

[0228] 70: pixel (first pixel)

[0229] 70B: first blue pixel

[0230] 70G: first green pixel

[0231] 70R: first red pixel

[0232] 71: second pixel

[0233] 71B: second blue pixel

[0234] 71G: second green pixel

[0235] 71R: second red pixel

[0236] 72: display unit

[0237] 72B: blue display unit

[0238] 72G: green display unit

[0239] 72R: red display unit

[0240] 73: color element

[0241] 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 1100A, 1100B: liquid crystal panel

[0242] 101: first electrode drive circuit

[0243] 102: second electrode drive circuit

[0244] 103: third electrode drive circuit

[0245] 200: control circuit

[0246] 201: image signal synthesis circuit

[0247] 202: display mode selection circuit

[0248] 203: third electrode applied voltage switching circuit

[0249] 204: luminance modulation circuit

[0250] 205: database

[0251] 211: original image signal

[0252] 212: image signal

[0253] 213: display mode switching signal

[0254] 214: first display mode selection signal

[0255] 215: second display mode selection signal

[0256] 216: drive voltage signal

[0257] 217: constant voltage signal

[0258] 218: luminance modulation signal

[0259] 219: visual control display switching signal

[0260] 220: view angle control pattern image signal

[0261] 300: backlight

[0262] 301: backlight driving circuit

[0263] 310: light guide plate

[0264] 311: light source

[0265] 312: light-shielding louver

[0266] 312a: light-transmitting layer

[0267] 312b: light-absorbing layer

[0268] 313: reflective sheet

[0269] 314: prismatic sheet

[0270] 315: diffusing sheet

Claims

1. A liquid crystal display device comprising: A liquid crystal panel in which a plurality of pixels are arranged in a matrix form; and a control circuit, the liquid crystal display device characterized by the liquid crystal panel having, in order, an active matrix substrate, a liquid crystal layer, and a color filter substrate, the active matrix substrate having, in order, a first substrate; a first electrode; a first insulating layer; and a plurality of second electrodes arranged for each of the pixels and having a first linear electrode portion extending in a first direction, the color filter substrate having a second substrate; a black matrix arranged between the plurality of pixels; a color filter; a third electrode; and a fourth electrode arranged between the black matrix and the third electrode and applied with a constant voltage, the third electrode including a second linear electrode portion extending in a second direction intersecting the first direction and overlapping at least a portion of the black matrix when viewed in plan, the control circuit performing switching control of applying a driving voltage to the third electrode and applying a constant voltage, the third electrode including a third linear electrode portion extending in the second direction when viewed in plan and arranged so as to overlap an optical opening portion of the pixel, the third linear electrode portion being arranged at a center of the optical opening portion of the pixel, an angle formed by the first direction and the second direction being 80° or more and 100° or less.

2. The liquid crystal display device according to claim 1, characterized in that the fourth electrode overlaps the third linear electrode portion at the optical opening portion of the pixel.

3. The liquid crystal display device according to claim 1, characterized in that the fourth electrode is provided with an opening at a position overlapping the third linear electrode portion when viewed in plan.

4. The liquid crystal display device according to claim 1, characterized in that the color filter substrate has, in order, the second substrate, the black matrix, the color filter, a first dielectric layer, the fourth electrode, a second dielectric layer, and the third electrode.

5. The liquid crystal display device according to claim 1, characterized in that the color filter substrate has, in order, the second substrate, the black matrix, the fourth electrode, the color filter, a second dielectric layer, and the third electrode.

6. The liquid crystal display device according to claim 4 or 5, wherein a third dielectric layer is provided between the third electrode and the liquid crystal layer.

7. The liquid crystal display device according to any one of claims 1 to 5, characterized in that the third electrode is formed of a transparent conductive material.

8. The liquid crystal display device according to any one of claims 1 to 5, characterized in that the active matrix substrate has a gate wiring and a source wiring arranged so as to intersect the gate wiring, the gate wiring extends in the second direction.

9. The liquid crystal display device according to claim 8, characterized in that at least a portion of the second linear electrode portion overlaps the gate wiring when viewed in plan.

10. The liquid crystal display device according to any one of claims 1 to 5, characterized in that The control circuit is capable of switching between a first display mode and a second display mode, the first display mode displaying a first image that can be observed from a narrow viewing angle range including a normal direction of the liquid crystal panel, the second display mode being capable of observing the first image from a wide viewing angle range including the narrow viewing angle range, The control circuit controls the third electrode to apply the driving voltage in the first display mode and to apply the constant voltage in the second display mode.

11. The liquid crystal display device according to claim 10, wherein A backlight is provided on a back surface of the liquid crystal panel, The backlight includes a light source and a light-shielding shutter provided on the liquid crystal panel side of the light source, The control circuit controls the backlight so that a luminance of the backlight in the first display mode is lower than a luminance of the backlight in the second display mode.

Images