Liquid crystal display device

Abstract

A liquid crystal display device is provided that can switch between a transparent state and a scattering state, suppressing the decrease in transmittance in the transparent state and suppressing the decrease in brightness of the central portion of the panel in the scattering state. The liquid crystal display device comprises, in sequence from the viewing surface to the back surface: a first liquid crystal panel, a light source, and a second liquid crystal panel. The first liquid crystal panel has a polymer-dispersed liquid crystal comprising a polymer network and liquid crystal components, and the light source illuminates the main surface of the back surface of the first liquid crystal panel from an oblique direction.

Description

Technical Field

[0001] The following disclosure relates to liquid crystal display devices. Background Technology

[0002] Liquid crystal display (LCD) devices are display devices that utilize liquid crystal compositions for display purposes. A typical display method involves applying a voltage to the liquid crystal composition sealed between a pair of substrates. The applied voltage causes changes in the orientation of the liquid crystal molecules within the composition, thereby controlling the amount of light transmitted. These LCD devices are characterized by their thinness, light weight, and low power consumption, and are used in a wide range of fields.

[0003] In recent years, the development of Field Sequential Color (FSC) has been advanced as one of the driving methods for liquid crystal display devices that display color images. The typical FSC method is as follows: the display period of one frame is divided into three subfields, and the red (R), green (G), and blue (B) LEDs (Light Emitting Diodes) that serve as the backlight light source are switched sequentially. At the same time, the image signals corresponding to the colors of the light from each LED are provided to the liquid crystal panel in sequence to control its transmission state, and additive color mixing is performed on the retina of the observer's eye.

[0004] According to the FSC method, color display can be achieved without forming multiple sub-pixels in a single pixel, thus enabling high resolution. Furthermore, since it directly utilizes light from the LEDs, there is no need to form high-absorption color filters in each pixel, improving the light utilization efficiency of each LED.

[0005] In addition, in recent years, see-through displays capable of displaying the back of a liquid crystal display device have attracted attention. As a liquid crystal display device used as a see-through display, liquid crystal display devices employing polymer-dispersed liquid crystals (PDLCs) have been developed. PDLCs contain liquid crystal components dispersed within a polymer network. By applying voltage, the orientation state of the liquid crystal components changes, thereby allowing the switching between a transparent state and a scattering state utilizing the refractive index difference between the liquid crystal components and the polymer network.

[0006] As a technology related to perspective displays using the FSC method, for example, Patent Document 1 discloses a liquid crystal display device having two liquid crystal panels and driving a light source in an FSC manner, thereby enabling color display without the need for a color filter. Additionally, Patent Document 2 discloses a liquid crystal display device that uses FSC driving to direct light irradiated from a light source toward a light modulation layer disposed between a pair of transparent substrates.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Publication No. 2015 / 053023

[0010] Patent Document 2: Japanese Patent Application Publication No. 2016-85452 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] The liquid crystal display device in the aforementioned patent document 1 achieves transparent or color display by combining a polarizing plate with an FSC drive. Therefore, the transmittance is insufficient (e.g., to the extent of 25%) during transmissive display.

[0013] Furthermore, Patent Document 2 describes a method of guiding light from a light source driven by an FSC arranged along the side of the liquid crystal panel into the interior of the light modulation layer (e.g., a polymer-dispersed liquid crystal). Therefore, due to light losses caused by diffraction or scattering from the thin-film transistors or polymer-dispersed liquid crystal inside the liquid crystal panel, the light from the side attenuates significantly as it travels towards the center of the liquid crystal panel. In cases where liquid crystal panels are enlarged, sufficient brightness may not be achieved in the center of the panel. Consequently, the size of liquid crystal panels is limited, making it difficult to achieve medium to large sizes.

[0014] The present invention was made in view of the above-mentioned situation, and its object is to provide a liquid crystal display device that can switch between a transparent state and a scattering state, suppress the decrease in transmittance in the transparent state, and suppress the decrease in brightness of the central part of the panel in the scattering state.

[0015] Solution for solving the problem

[0016] (1) One embodiment of the present invention is a liquid crystal display device comprising, in sequence from the viewing side to the back side: a first liquid crystal panel, a light source and a second liquid crystal panel, wherein the first liquid crystal panel comprises a polymer-dispersed liquid crystal comprising a polymer network and a liquid crystal component, and the light source irradiates the main surface of the back side of the first liquid crystal panel from an inclined direction.

[0017] (2) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the configuration described in (1), displays an image in field-sequential color mode, and the light source includes a plurality of light-emitting elements that emit light of different colors.

[0018] (3) In addition, one embodiment of the present invention is a liquid crystal display device, wherein, based on the configuration described in (1) or (2) above, the first liquid crystal panel further comprises a thin film transistor.

[0019] (4) In addition, one embodiment of the present invention is a liquid crystal display device in which, based on the above (1), (2) or (3), when the length of the long side of the first liquid crystal panel is set to 2a [cm], the distance between the first liquid crystal panel and the second liquid crystal panel is a [cm] or less.

[0020] (5) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the configurations described in (1), (2), (3) or (4) above, satisfies the following (Equation 1-1): when the length of the long side of the first liquid crystal panel is set to 2a [cm], the distance between the first liquid crystal panel and the light source is set to h11 [cm], and the incident angle of the light from the light source on the main surface of the back side of the first liquid crystal panel is set to θ11 [°]:

[0021] 1≤h11≤{a / (tanθ11)}…(Formula 1-1).

[0022] (6) In addition, one embodiment of the present invention is a liquid crystal display device, which is based on the configuration of (1), (2), (3), (4) or (5) above. The light source is a first light source and is provided corresponding to one of the pair of opposing end edge portions of the first liquid crystal panel. A second light source is also provided between the first liquid crystal panel and the second liquid crystal panel. The second light source is provided corresponding to the other end edge portion of the pair of end edge portions. The second light source irradiates the main surface of the back side of the first liquid crystal panel from an inclined direction. The incident angle of the light from the first light source to the main surface of the back side of the first liquid crystal panel is the same as the incident angle of the light from the second light source to the main surface of the back side of the first liquid crystal panel.

[0023] (7) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the above (1), (2), (3), (4), (5) or (6), also provides a back-side light source between the above light source and the above second liquid crystal panel, and the back-side light source illuminates the main surface of the back side of the above first liquid crystal panel from an inclined direction.

[0024] (8) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the configuration described in (7) above, satisfies the following (Equation 1-1) and (Equation 2-1): when the length of the long side of the first liquid crystal panel is set to 2a [cm], the distance between the first liquid crystal panel and the light source is set to h11 [cm], the incident angle of the light from the light source on the main surface of the back side of the first liquid crystal panel is set to θ11 [°], and the incident angle of the light from the back side light source on the main surface of the back side of the first liquid crystal panel is set to θ21 [°].

[0025] 1≤h11≤{a / (tanθ11)}…(Formula 1-1)

[0026] θ11-θ21>10°…(Formula 2-1).

[0027] (9) In addition, one embodiment of the present invention is a liquid crystal display device, based on the configuration described in (7) or (8) above, wherein the back-side light source is a first back-side light source and is provided corresponding to one of the pair of opposing end-side portions of the first liquid crystal panel, and a second back-side light source is provided between the light source and the second liquid crystal panel, wherein the second back-side light source is provided corresponding to the other end-side portion of the pair of end-side portions, and the second back-side light source irradiates the main surface of the back side of the first liquid crystal panel from an inclined direction, wherein the incident angle of the light from the first back-side light source on the main surface of the back side of the first liquid crystal panel is the same as the incident angle of the light from the second back-side light source on the main surface of the back side of the first liquid crystal panel.

[0028] (10) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the above-described (1), (2), (3), (4), (5), (6), (7), (8) or (9), further comprises: a first support substrate disposed on the back side of the polymer-dispersed liquid crystal; and a second support substrate disposed on the viewing surface side of the polymer-dispersed liquid crystal.

[0029] (11) In addition, one embodiment of the present invention is a liquid crystal display device, in which the first liquid crystal panel further comprises an alignment film based on the above (10) configuration, the alignment film being disposed between the first support substrate and the polymer-dispersed liquid crystal and between the second support substrate and the polymer-dispersed liquid crystal, the alignment film being a horizontal alignment film in which the liquid crystal components are aligned parallel to the surface of the alignment film.

[0030] (12) In addition, one embodiment of the present invention is a liquid crystal display device, wherein, based on the above-described (11) configuration, the liquid crystal component has positive dielectric constant anisotropy.

[0031] (13) In addition, one embodiment of the present invention is a liquid crystal display device, in which the first liquid crystal panel further comprises a transparent resin plate disposed on the back side of the first support substrate, based on the configuration described in (10), (11) or (12) above.

[0032] (14) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the above (10), (11), (12) or (13), provides an anisotropic light diffusion film on at least one of the back side of the first support substrate and the viewing side of the second support substrate. The anisotropic light diffusion film has the function of allowing light to pass through when viewed from the front and scattering light when viewed at an angle.

[0033] (15) In addition, one embodiment of the present invention is a liquid crystal display device, which, based on the configuration of (1), (2), (3), (4), (5), (6), (7), (8) or (9), (10), (11), (12), (13) or (14) described above, comprises, in sequence from the back side to the viewing side: a third support substrate; a liquid crystal layer; a fourth support substrate; and an anisotropic light-reflecting film, which has the function of allowing light to pass through when viewed from the front and reflecting light when viewed at an angle.

[0034] Invention Effects

[0035] According to the present invention, a liquid crystal display device is provided that can switch between a transparent state and a scattering state, suppress the decrease in transmittance in the transparent state, and suppress the decrease in brightness of the central part of the panel in the scattering state. Attached Figure Description

[0036] Figure 1 This is an example of a cross-sectional schematic diagram of the liquid crystal display device according to Embodiment 1.

[0037] Figure 2A This is a cross-sectional schematic diagram illustrating the transparent state of the first liquid crystal panel included in the liquid crystal display device of Embodiment 1.

[0038] Figure 2B This is a cross-sectional schematic diagram illustrating the scattering state of the first liquid crystal panel included in the liquid crystal display device of Embodiment 1.

[0039] Figure 3This is a block diagram showing the overall configuration of the liquid crystal display device according to Embodiment 1.

[0040] Figure 4 This is a diagram showing the configuration of one frame period in the liquid crystal display device according to Embodiment 1.

[0041] Figure 5 This is a cross-sectional schematic diagram of the second liquid crystal panel included in the liquid crystal display device of Embodiment 1.

[0042] Figure 6 This is a cross-sectional schematic diagram of the liquid crystal display device according to Embodiment 2.

[0043] Figure 7 This is a cross-sectional schematic diagram of the liquid crystal display device in Modified Example 1.

[0044] Figure 8 This is a cross-sectional schematic diagram of the liquid crystal display device in Modified Example 2.

[0045] Figure 9 This is a three-dimensional schematic diagram of the light-shielding grille provided in the liquid crystal display device of Modified Example 2.

[0046] Figure 10A This is an example of a cross-sectional schematic diagram of a liquid crystal display device, which is a variation of Example 3.

[0047] Figure 10B This is an example of a cross-sectional schematic diagram of a liquid crystal display device, which is a variation of Example 3.

[0048] Figure 10C This is an example of a cross-sectional schematic diagram of a liquid crystal display device, which is a variation of Example 3.

[0049] Figure 10D This is an example of a cross-sectional schematic diagram of a liquid crystal display device, which is a variation of Example 3.

[0050] Figure 11A This is a three-dimensional schematic diagram of the anisotropic light diffusion film of the liquid crystal display device in Modified Example 3.

[0051] Figure 11B This is a cross-sectional schematic diagram of the anisotropic light diffusion film of the liquid crystal display device in Modified Example 3.

[0052] Figure 12 This is a three-dimensional schematic diagram of the anisotropic light diffusion film of the liquid crystal display device in Modified Example 3.

[0053] Figure 13A This is an example of a cross-sectional schematic diagram of the anisotropic light diffusion film in the liquid crystal display device of Modified Example 3.

[0054] Figure 13BThis is an example of a cross-sectional schematic diagram of the anisotropic light diffusion film in the liquid crystal display device of Modified Example 3.

[0055] Figure 14 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-2.

[0056] Figure 15A This is a graph showing the angle dependence of the transmittance of the light-shielding grating provided in the liquid crystal display devices of Embodiments 1-2.

[0057] Figure 15B yes Figure 15A The diagram shown is an enlarged view of the area enclosed by quadrilaterals.

[0058] Figure 15C This is a schematic diagram illustrating a method for measuring the angle dependence of the transmittance of the light-shielding grating in the liquid crystal display device of Examples 1-2.

[0059] Figure 16 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-3.

[0060] Figure 17 This is a schematic diagram illustrating a method for determining the angle dependence of the transmittance of an optical film.

[0061] Figure 18 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-4.

[0062] Figure 19 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-5.

[0063] Figure 20 This is a cross-sectional schematic diagram of the liquid crystal display device in Embodiment 2-1.

[0064] Figure 21 This is a cross-sectional schematic diagram of the liquid crystal display device in Example 2-2.

[0065] Figure 22 This is a cross-sectional schematic diagram of the liquid crystal display device of Comparative Example 1.

[0066] Figure 23 This is a diagram illustrating the evaluation of LED highlights.

[0067] Explanation of reference numerals in the attached figures

[0068] 1. 1RF: Liquid Crystal Display Device

[0069] 1B, 1G, 1R: Input grayscale data

[0070] 1b, 1g, 1r: Apply grayscale data

[0071] 4: Pixel forming section

[0072] 11: First LCD panel

[0073] 11A: Display Unit

[0074] 11P: Main face on the back side

[0075] 11X: One end edge portion

[0076] 11Y: The other end

[0077] 12: Second LCD panel

[0078] 13: Blackout grille

[0079] 14: Anisotropic light diffusion film

[0080] 15: Anisotropic light-reflecting film

[0081] 20: Transparent resin board

[0082] 31X: First Light Source

[0083] 31Y: Second light source

[0084] 32X: First rear-side light source

[0085] 32Y: Second rear-side light source

[0086] 31B, 31G, 31R: LED (Light Emitting Diode)

[0087] 40: TFT (Thin Film Transistor)

[0088] 42: Liquid Crystal Capacitor

[0089] 43: Auxiliary capacitor

[0090] 45: Auxiliary capacitor electrode

[0091] 46: Pixel Capacitor

[0092] 50, 50R: Backlight

[0093] 51R: LED light source

[0094] 52R: Light guide plate

[0095] 61X: First Shot

[0096] 61Y: Second Shot

[0097] 62X: Third Mirror

[0098] 62Y: Fourth Frame

[0099] 63X: The Fifth Frame

[0100] 63Y: The Sixth Mirror

[0101] 70X: First brightness enhancement film

[0102] 70Y: Second brightness enhancement film

[0103] 80: Adhesive components

[0104] 100: First substrate

[0105] 110: First supporting substrate

[0106] 120, 620: Pixel Electrode

[0107] 131: Grid layer

[0108] 132: Transparent film

[0109] 200: Second substrate

[0110] 210: Second support substrate

[0111] 220, 930: Shared electrode

[0112] 300: Polymer-dispersed liquid crystal

[0113] 310: Polymer Network

[0114] 320: Liquid crystal composition

[0115] 410: First orientation film

[0116] 420: Second-Orientation Film

[0117] 510: First polarizing plate

[0118] 520: Second polarizing plate

[0119] 600: Third substrate

[0120] 610: Third support substrate

[0121] 710: Third-Orientation Membrane

[0122] 720: Fourth-Oriented Membrane

[0123] 800: Liquid Crystal Layer

[0124] 900: Fourth substrate

[0125] 910: Fourth Supporting Substrate

[0126] 920: Color filter layer

[0127] 1000: Pre-processing Department

[0128] 1100: Signal separation circuit

[0129] 1200: Data Correction Circuit

[0130] 1300(R): Red Field Memory

[0131] 1300(G) Green Field Memory

[0132] 1300(B): Blue Field Memory

[0133] 1311: Light-shielding layer

[0134] 1312: Transparent layer

[0135] 2000: Timer Controller

[0136] 3100: Gate driver

[0137] 3200: Source Driver

[0138] 3300: LED Driver

[0139] 4011: Region with relatively low refractive index

[0140] 4012, 4012′: Regions with relatively high refractive index

[0141] 4012a, 4012a′: columnar structures

[0142] 4014: Bending section

[0143] 4020: First Internal Structure

[0144] 4020a, 4030a: Column structure

[0145] 4020b, 4030b: Grid structure

[0146] 4030: Second Internal Structure

[0147] 4050: Light diffusion layer

[0148] DIN: Input image signal

[0149] DV: Digital video signal

[0150] GCK: Gate clock signal

[0151] GSP: Gate Start Pulse Signal

[0152] GL, GL1~GLm: Gate lines

[0153] LS: Latch strobe signal

[0154] S1: LED driver control signal

[0155] S2: Light source control signal

[0156] SCK: Source clock signal

[0157] SL, SL1~SLn: Source lines

[0158] SSP: Source Start Pulse Signal. Detailed Implementation

[0159] The present invention will now be described in more detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

[0160] <Definitions of Terms>

[0161] In this specification, "viewing side" refers to the side closer to the screen (display surface) of the polymer dispersion liquid crystal display device, and "back side" refers to the side further away from the screen (display surface) of the polymer dispersion liquid crystal display device.

[0162] <Implementation Method 1>

[0163] Figure 1 This is an example of a cross-sectional schematic diagram of the liquid crystal display device according to Embodiment 1. For example... Figure 1 As shown, the liquid crystal display device 1 of this embodiment includes, in sequence from the viewing surface side to the back surface side: a first liquid crystal panel 11, a first light source 31X serving as the light source, a second liquid crystal panel 12, and a backlight 50.

[0164] Figure 2A This is a cross-sectional schematic diagram illustrating the transparent state of the first liquid crystal panel included in the liquid crystal display device of Embodiment 1. Figure 2B This is a cross-sectional schematic diagram illustrating the scattering state of the first liquid crystal panel included in the liquid crystal display device of Embodiment 1. Figure 2A and Figure 2B It is along Figure 1 A schematic diagram of the cross-section of line X1-X2 in the diagram. (See attached diagram.) Figure 2A and Figure 2B As shown, the first liquid crystal panel 11 includes a polymer-dispersed liquid crystal 300 comprising a polymer network 310 and liquid crystal components 320, and can switch between a transparent state and a scattering state. Furthermore, since the first liquid crystal panel 11 includes the polymer-dispersed liquid crystal 300, image display can be performed without using a polarizing plate, and the decrease in transmittance in the transparent state can be suppressed.

[0165] like Figure 1As shown, the first light source 31X illuminates the main surface 11P on the back side of the first liquid crystal panel 11 from an oblique direction. By configuring it in this way, compared to the case where light from the first light source 31X travels within the first liquid crystal panel 11 or the polymer-dispersed liquid crystal 300, the attenuation of light in the central portion of the liquid crystal panel can be suppressed, and the decrease in brightness (more specifically, front brightness) of the central portion of the panel in a scattered state can be suppressed. As a result, the display screen can be enlarged. Furthermore, in this specification, the main surface on the back side of the first liquid crystal panel refers to the surface of the first liquid crystal panel on the light source side. Additionally, the central portion of the panel refers to the central portion of the display screen of the first liquid crystal panel, and the area within the panel surface refers to the area within the display screen of the first liquid crystal panel.

[0166] For example, in the liquid crystal display device described in Patent Document 2, where a light source driven by an FSC arranged along the side of the liquid crystal panel is guided into the interior of the light modulation layer (specifically, a polymer-dispersed liquid crystal), when light is incident from the long side of the liquid crystal panel in a 12.3-inch liquid crystal panel, the light can only be guided to a distance of approximately 10 cm.

[0167] Furthermore, in a 19-inch liquid crystal panel (30cm x 40cm), by guiding the light from a light source driven by an FSC method within the panel, switching between transparent and color display is possible. However, it is conceivable that at this size, due to light losses such as diffraction or scattering caused by the TFTs or polymer-dispersed liquid crystals (PDLC) within the panel, the brightness in the center of the liquid crystal panel becomes extremely low. Specifically, when light is incident from the short side of the liquid crystal panel, it can only be guided to a practical distance of 20cm. Moreover, the illumination method of irradiating the main surface 11P on the back side of the first liquid crystal panel 11 from an oblique direction is also called an oblique incidence method, and the illumination method of guiding light within a light guide plate or the panel is also called a light guiding method. Hereinafter, the liquid crystal display device 1 of this embodiment will be described in detail.

[0168] like Figure 2A and Figure 2B As shown, the first liquid crystal panel 11 includes: a first substrate 100, which is one of the aforementioned pair of substrates; a polymer-dispersed liquid crystal 300; and a second substrate 200, which is the other of the aforementioned pair of substrates. The first substrate 100 includes a first support substrate 110 and a pixel electrode 120. The second substrate 200 includes a second support substrate 210 and a common electrode 220.

[0169] Preferably, the first liquid crystal panel 11 includes a thin film transistor (TFT). Light irradiated from the first light source 31X can sometimes be attenuated due to diffraction or scattering caused by the TFTs within the liquid crystal panel. However, in the liquid crystal display device 1 of this embodiment, since the first light source 31X irradiates the main surface 11P on the back side of the first liquid crystal panel 11 from an oblique direction, even when the first liquid crystal panel 11 includes a TFT, the light attenuation caused by the aforementioned TFTs can be suppressed, and the decrease in brightness of the central portion of the panel under scattering conditions can be effectively suppressed. Hereinafter, a scheme in which the first liquid crystal panel (specifically, the first substrate 100) includes a TFT will be described, but it is not limited to this.

[0170] The first substrate 100 is a substrate provided with TFTs, which serve as switching elements for switching the pixels of the first liquid crystal panel 11 on / off. In this embodiment, the configuration of the first substrate 100 for TN mode will be described.

[0171] The first substrate 100 comprises, in sequence from the back side to the viewing side: a first support substrate 110; a plurality of gate lines extending parallel to each other; a gate insulating film; a plurality of source lines extending parallel to each other in a direction intersecting with each gate line; an interlayer insulating film; and a pixel electrode 120. The plurality of gate lines and the plurality of source lines are generally formed in a grid pattern to separate each pixel. A TFT serving as a switching element is disposed at the intersection of each gate line and each source line. A pixel electrode 120 is disposed in each region surrounded by two adjacent gate lines and two adjacent source lines.

[0172] Each TFT is a three-terminal switch, comprising: a gate electrode connected to a corresponding gate line among a plurality of gate lines, protruding from the corresponding gate line (as part of the gate line); a source electrode connected to a corresponding source line among a plurality of source lines, protruding from the corresponding source line (as part of the source line); a drain electrode connected to a corresponding pixel electrode among a plurality of pixel electrodes; and a thin-film semiconductor layer. The source and drain electrodes are electrodes disposed in the same source wiring layer as the source lines, and the gate electrode is an electrode disposed in the same gate wiring layer as the gate lines.

[0173] Each TFT's thin-film semiconductor layer is composed of, for example, a high-resistance semiconductor layer and a low-resistance semiconductor layer. The high-resistance semiconductor layer includes amorphous silicon, polycrystalline silicon, etc., while the low-resistance semiconductor layer includes n+ amorphous silicon doped with impurities such as phosphorus. Alternatively, oxide semiconductor layers such as zinc oxide can also be used as thin-film semiconductor layers. Examples of oxide semiconductor layers include In-Ga-Zn-O (indium gallium zinc oxide), which is composed primarily of indium (In), gallium (Ga), zinc (Zn), and oxygen (O). By employing this In-Ga-Zn-O-TFT, not only can higher resolution or lower power consumption be achieved, but the write speed can also be improved compared to previous methods. Furthermore, the same effect can be obtained when using an oxide semiconductor layer containing at least one of indium, gallium, zinc, copper (Cu), silicon (Si), tin (Sn), aluminum (Al), calcium (Ca), germanium (Ge), and lead (Pb).

[0174] Preferably, the first support substrate 110 and the second support substrate 210 are transparent substrates, such as glass substrates and plastic substrates.

[0175] The gate insulating film is, for example, an inorganic insulating film. As an inorganic insulating film, inorganic films (relative permittivity ε = 5 to 7) such as silicon nitride (SiNx) and silicon oxide (SiO2) or their laminates can be used.

[0176] The gate and source wiring layers are, for example, single or multiple layers of metals such as copper, titanium, aluminum, molybdenum, and tungsten, or their alloys. The various wirings and electrodes constituting the gate lines, source lines, and TFTs can be formed by depositing single or multiple layers of metals such as copper, titanium, aluminum, molybdenum, and tungsten, or their alloys, using sputtering or similar methods, followed by patterning using photolithography or similar methods. Using the same material for the wirings and electrodes formed in the same layer among these various wirings and electrodes improves manufacturing efficiency.

[0177] Interlayer insulating films are, for example, inorganic insulating films. As inorganic insulating films, such as silicon nitride (SiNx), silicon oxide (SiO2), etc. (relative permittivity ε = 5 to 7) or laminates thereof can be used.

[0178] The pixel electrode 120 is an electrode arranged in a planar (full-surface) configuration in each region surrounded by two adjacent gate lines and two adjacent source lines. The pixel electrode 120 is electrically connected to the corresponding source line via a thin-film semiconductor layer of the TFT. The pixel electrode 120 is set to a potential corresponding to the data signal supplied via the corresponding TFT.

[0179] The common electrode 220 is an electrode formed on approximately one surface of the second support substrate 210, independent of the pixel boundary. A common signal is supplied to the common electrode 220 and maintained at a constant value, thus keeping the common electrode 220 at a constant potential.

[0180] Materials used for the pixel electrode 120 and the common electrode 220 include, for example, indium tin oxide (ITO) and indium zinc oxide (IZO).

[0181] The polymer-dispersed liquid crystal 300 has a polymer network 310 and a liquid crystal component 320, and is sandwiched between a first substrate 100 and a second substrate 200. In the polymer-dispersed liquid crystal 300, the fibrous matrix of the cured photopolymerizable liquid crystal compound aggregates to form a three-dimensional continuous polymer network 310, in which the liquid crystal component 320 is in a phase-separated state.

[0182] The polymer-dispersed liquid crystal 300 comprises a polymer network 310 composed of a cured product of a photopolymerizable liquid crystal compound and a liquid crystal component 320. It is transparent when no voltage is applied and scattering when a voltage is applied. This configuration enables a display device that does not require a polarizing plate. More specifically, it is transparent when no voltage is applied, and when a voltage is applied, the orientation of the liquid crystal component 320 changes, resulting in a scattering state.

[0183] Here, "no voltage applied" refers to the applied voltage to the polymer-dispersed liquid crystal 300 being less than the threshold voltage (including no voltage applied), while "voltage applied" refers to the applied voltage to the polymer-dispersed liquid crystal 300 being greater than or equal to the threshold voltage. The "no voltage applied" state is also referred to as the "no voltage applied state," and the "voltage applied" state is also referred to as the "voltage applied state."

[0184] The following uses Figure 2A and Figure 2B This is to illustrate the orientation state of liquid crystal component 320 in the transparent and scattering states. Figure 2A and Figure 2B The central portion of the first liquid crystal panel 11 is shown.

[0185] like Figure 2A As shown, preferably, when no voltage is applied, the orientation of the polymer network 310 and the liquid crystal component 320 is approximately equal. Figure 2AThe illustration shows a case where both the polymer network 310 and the liquid crystal component 320 are homogeneously oriented relative to the main surfaces of the first substrate 100 and the second substrate 200. When no voltage is applied, there is virtually no refractive index difference between the liquid crystal component 320 and the polymer network 310 (both the anomalous refractive index ne and the ordinary refractive index no) in all directions, including the thickness direction of the polymer-dispersed liquid crystal 300. Therefore, light irradiated from the light source passes through the polymer-dispersed liquid crystal 300, resulting in a transparent state. Furthermore, the state in which there is virtually no refractive index difference between the liquid crystal component 320 and the polymer network 310 (both the anomalous refractive index ne and the ordinary refractive index no) in all directions, including the thickness direction of the polymer-dispersed liquid crystal 300, can also be described as a state in which the refractive indices of the liquid crystal component 320 and the polymer network 310 are matched.

[0186] A transparent state refers to a state in which the liquid crystal is transparent to light. For example, the transmittance of the polymer-dispersed liquid crystal 300 in a transparent state can be 80% or more, or it can be 90% or more. Furthermore, the upper limit of the transmittance of the polymer-dispersed liquid crystal 300 in a transparent state is, for example, 100%. In this embodiment, the polymer-dispersed liquid crystal 300 in a transparent state is transparent to visible light. In this specification, the transmittance of the polymer-dispersed liquid crystal in a transparent state refers to the transmittance of parallel light rays from the polymer-dispersed liquid crystal in a transparent state. The transmittance of the polymer-dispersed liquid crystal in a transparent state can be determined, for example, in the following manner: Using a luminance meter (SR-UL1) manufactured by Topcon, the luminance is measured at a 2° angle when a first liquid crystal panel with polymer-dispersed liquid crystal is disposed on a conventional backlight (light source for a liquid crystal display device) with a halogen lamp as the light source, in a state without applied voltage, and when nothing is disposed on the aforementioned backlight. The measurement wavelength is set to approximately 550 nm, which is the wavelength with the highest visual reflectance Y value, representing the visual sensitivity of the human eye. By dividing the brightness of the first liquid crystal panel in the case where no voltage is applied on the backlight by the brightness when nothing is placed on the backlight, the transmittance of the polymer-dispersed liquid crystal in the transparent state can be determined.

[0187] like Figure 2BAs shown, when a voltage is applied, the polymer network 310 remains horizontally aligned relative to the main surfaces of the first substrate 100 and the second substrate 200, while the liquid crystal component 320 is oriented in the vertical direction. When a voltage is applied, the orientation of the liquid crystal component 320 changes due to the electric field formed in the polymer-dispersed liquid crystal 300, while the polymer network 310 is unaffected by the electric field. Therefore, in all directions, including the thickness direction of the polymer-dispersed liquid crystal 300, the refractive index difference between the liquid crystal component 320 and the polymer network 310 (abnormal light refractive index ne) and the refractive index difference between the liquid crystal component 320 and the polymer network 310 (ordinary light refractive index no) increases. When unpolarized light from the first light source 31X is incident obliquely onto the polymer-dispersed liquid crystal 300, unlike the case where unpolarized light is incident perpendicularly onto the polymer-dispersed liquid crystal 300, scattering occurs independently of polarization; therefore, the polymer-dispersed liquid crystal 300 becomes a strongly scattered state. Furthermore, a state in which the refractive index difference between the liquid crystal component 320 and the polymer network 310 is large in all directions, including the thickness direction of the polymer-dispersed liquid crystal 300, as well as the refractive index difference between the liquid crystal component 320 and the polymer network 310, can also be described as a state of refractive index mismatch between the liquid crystal component 320 and the polymer network 310.

[0188] The scattering state refers to the state in which light is scattered. For example, the transmittance of the polymer-dispersed liquid crystal 300 in the scattering state may be 50% or less. Furthermore, the lower limit of the transmittance of the polymer-dispersed liquid crystal 300 in the scattering state is, for example, 0 to 1%. In this specification, the transmittance of the polymer-dispersed liquid crystal in the scattering state refers to the transmittance of parallel light rays from the polymer-dispersed liquid crystal in the scattering state. The transmittance of the polymer-dispersed liquid crystal in the scattering state can be determined, for example, as follows: Using a luminance meter (SR-UL1) manufactured by Topcon, the luminance is measured at a 2° angle when a first liquid crystal panel with a polymer-dispersed liquid crystal in an applied voltage state is disposed on a conventional backlight (light source for a liquid crystal display device) equipped with a halogen lamp as a light source, and the luminance is measured when nothing is disposed on the aforementioned backlight. The measurement wavelength is set to approximately 550 nm, which is the wavelength with the highest visual reflectance Y value, representing the visual sensitivity of the human eye. The transmittance of the polymer-dispersed liquid crystal in a scattering state can be determined by dividing the brightness of the first liquid crystal panel in the applied voltage state disposed on the backlight by the brightness of the backlight without any backlight.

[0189] Furthermore, the haze, which represents the light scattering rate of the polymer-dispersed liquid crystal 300 in a scattering state, varies depending on the applied voltage, but can be, for example, 80% or more, or 90% or more. Additionally, the upper limit of the haze, representing the light scattering rate of the polymer-dispersed liquid crystal 300 in a scattering state, is, for example, 90 to 100%. In this embodiment, the polymer-dispersed liquid crystal 300 in a scattering state scatters visible light. Therefore, the polymer-dispersed liquid crystal 300 in a scattering state is in the same state as frosted glass. In this specification, the haze is measured according to the method of JIS K7136. The aforementioned haze can be measured, for example, using a turbidimeter such as the "Haze Meter NDH2000" manufactured by Nippon Denshoku Kogyo Co., Ltd., with a halogen lamp as the light source.

[0190] A liquid crystal panel that is transparent when no voltage is applied and scatters when a voltage is applied is also called a reverse-type liquid crystal panel. Conventionally, in reverse-type liquid crystal panels, when unpolarized light is incident perpendicularly onto the panel, only one of the polarized light (s-polarized or p-polarized) contributes to scattering. Therefore, the transmittance in the scattered state is as high as 50%, making it impossible to scatter light sufficiently. This is because when light from a light source is incident perpendicularly onto the main surface of the reverse-type liquid crystal panel, only one of the polarized light (s-polarized or p-polarized) can cause a mismatch in the refractive index between the liquid crystal component and the polymer network. On the other hand, in this embodiment, since the light is irradiated onto the main surface 11P of the back side of the first liquid crystal panel 11 from an inclined direction, a mismatch in the refractive index between the liquid crystal component and the polymer network can be achieved compared to both s-polarized and p-polarized light, thus resulting in stronger scattering. In this embodiment, for example, stronger scattering can be obtained compared to the case of using a reverse-type liquid crystal panel in which a chiral agent is introduced into the polymer-dispersed liquid crystal.

[0191] In this way, the liquid crystal display device 1 adjusts the amount of light transmitted through the first liquid crystal panel 11 by changing the refractive index difference between the liquid crystal component 320 and the polymer network 310 in the polymer dispersed liquid crystal 300, as well as the refractive index difference between ne and no. Therefore, the polarizing plate required in conventional liquid crystal display devices is not needed.

[0192] As a photopolymerizable liquid crystal compound used to form the polymer network 310, for example, it is a photopolymerizable liquid crystal compound that exhibits a liquid crystal phase at room temperature and is compatible with the liquid crystal component 320, and separates from the liquid crystal component 320 when it is cured by ultraviolet irradiation and forms a polymer.

[0193] Examples of photopolymerizable liquid crystal compounds include monomers having substituents such as biphenyl, terphenyl, naphthyl, phenylbenzoate, azophenyl, and their derivatives (hereinafter also referred to as mesocrystalline groups); photoreactive groups such as cinnamoyl, chalcone, cinnamylene, β-(2-phenyl)acryloyl, cinnamic acid, and their derivatives; and polymerizable groups such as acrylates, methacrylates, maleimides, N-phenylmaleimides, and siloxanes. Acrylates are preferred as polymerizable groups. Furthermore, the number of polymerizable groups per molecule of the photopolymerizable liquid crystal compound is not particularly limited, but one or two are preferred.

[0194] Liquid crystal component 320 may also not have polymeric groups such as acrylate, methacrylate, maleimide, N-phenylmaleimide, and siloxane.

[0195] In this embodiment, the liquid crystal component 320 can be a liquid crystal component with a positive dielectric constant anisotropy (Δε) as defined by the following formula (L), or it can be a liquid crystal component with a negative dielectric constant anisotropy (Δε). However, when the alignment films 410 and 420 described later are horizontal alignment films, a positive dielectric constant anisotropy is preferred. By adopting such an arrangement, strong scattering and low voltage driving can be more effectively balanced. The liquid crystal component (liquid crystal molecule) with a positive dielectric constant anisotropy is oriented in a direction parallel to the electric field direction, and the liquid crystal component (liquid crystal molecule) with a negative dielectric constant anisotropy is oriented in a direction perpendicular to the electric field direction. Furthermore, the liquid crystal component (liquid crystal molecule) with a positive dielectric constant anisotropy is also referred to as a positive liquid crystal, and the liquid crystal component (liquid crystal molecule) with a negative dielectric constant anisotropy is also referred to as a negative liquid crystal. In addition, the long axis direction of the liquid crystal component (liquid crystal molecule) is the direction of the hysteresis axis. In addition, the direction of the long axis of the liquid crystal component (liquid crystal molecule) when no voltage is applied is also called the direction of the initial orientation of the liquid crystal component (liquid crystal molecule).

[0196] Δε = (dielectric constant of the liquid crystal component (liquid crystal molecule) along its long axis) - (dielectric constant of the liquid crystal component (liquid crystal molecule) along its short axis) (L)

[0197] As liquid crystal component 320, for example, a diphenylacetylene (Tolan) based liquid crystal material (a liquid crystal material having -C≡C- (carbon-carbon triple bond) as a linking group) can be used.

[0198] Preferably, the refractive index anisotropy Δn of the liquid crystal component 320 is 0.18 or higher and 0.24 or lower, the dielectric constant anisotropy Δε of the liquid crystal component 320 is 15 or higher and 25 or lower, and the rotational viscosity γ1 of the liquid crystal component 320 is 100 mPa·s or higher and 300 mPa·s or lower. By adopting this configuration, both strong scattering and low-voltage driving can be achieved, and a response speed comparable to that of conventional liquid crystal display devices without a polymer network can be realized. This effect can be achieved by ensuring that the refractive index anisotropy Δn, dielectric constant anisotropy Δε, and rotational viscosity γ1 of the liquid crystal component 320 are all within the above-mentioned ranges.

[0199] As a specific example of a diphenylacetylene-based liquid crystal material, a liquid crystal material having a structure represented by the following general formula (L1) can be cited.

[0200] [Chemical Formula 1]

[0201]

[0202] (In the above formula, Q1 and Q2 independently represent aromatic cyclic groups, X represents a fluorine group or a cyano group, and n1 and n2 independently represent 0 or 1.)

[0203] In the above general formula (L1), n1 and n2 will not both be 0. That is, the sum of n1 and n2 is 1 or 2.

[0204] The aromatic ring group in the above general formula (L1) may also have substituents.

[0205] In the above general formula (L1), it is preferable that Q1 and Q2 are each independently any one of the following general formulas (L2-1) to (L2-7).

[0206] [Chemical Formula 2]

[0207]

[0208] As a specific structure of a liquid crystal material having a structure represented by the above general formula (L1), the following structures can be cited as examples.

[0209]

Chemical Formula 3

[0210]

[0211] The preferred weight ratio of liquid crystal component 320 to polymer network 310 is liquid crystal component:polymer network = 90:10 to 97:3. That is, the preferred weight ratio of liquid crystal component 320 is 90 or more and 97 or less. When the weight ratio of liquid crystal component 320 is 90 or more, the weight ratio of polymer network 310 is 10 or less; when the weight ratio of liquid crystal component 320 is 97 or less, the weight ratio of polymer network 310 is 3 or more. This configuration effectively balances strong scattering and low-voltage driving. When the weight ratio of polymer network 310 exceeds 10, strong scattering is achieved, but the driving voltage becomes higher. When the weight ratio of polymer network 310 is less than 3, the driving voltage is suppressed, but sometimes strong scattering is not achieved.

[0212] Preferably, the first liquid crystal panel 11 includes an alignment film disposed between at least one of a pair of substrates (first substrate 100 and second substrate 200) that hold the polymer-dispersed liquid crystal 300 and the polymer-dispersed liquid crystal 300. By configuring it in this way, when the applied voltage to the polymer-dispersed liquid crystal 300 is less than a threshold voltage (including no applied voltage), the orientation of the liquid crystal component 320 in the polymer-dispersed liquid crystal 300 can be controlled mainly by the action of the alignment film.

[0213] The following describes a configuration where a first alignment film 410 is provided between the first substrate 100 and the polymer-dispersed liquid crystal 300, and a second alignment film 420 is provided between the second substrate 200 and the polymer-dispersed liquid crystal 300, but this is not a limitation. For example, an alignment film may be provided only between either the first substrate 100 and the polymer-dispersed liquid crystal 300 or between the second substrate 200 and the polymer-dispersed liquid crystal 300, or no alignment film may be provided between either the first substrate 100 and the polymer-dispersed liquid crystal 300 or between the second substrate 200 and the polymer-dispersed liquid crystal 300. For example, if the first liquid crystal panel 11 has only one of the first alignment film 410 and the second alignment film 420, and this alignment film is a horizontal alignment film, if the other substrate side is smooth (zero anchoring), the liquid crystal component 320 will adopt a twisted horizontal alignment state. Therefore, as a result, the same alignment state as when horizontal alignment films are provided on both substrates can be achieved.

[0214] The first alignment film 410 and the second alignment film 420 are layers that have undergone alignment treatment to control the orientation of the liquid crystal component 320 and the photopolymerizable liquid crystal compound. Alignment films commonly used in the field of liquid crystal display devices, such as polyimide, can be used. The first alignment film 410 and the second alignment film 420 can be rub-adjusted films that have undergone rubbing treatment, or they can be photo-adjusted films that have undergone photo-alignment treatment. Hereinafter, the liquid crystal component 320 and the photopolymerizable liquid crystal compound will be simply referred to as liquid crystal molecules.

[0215] Friction alignment films can be obtained, for example, by forming an alignment film material containing a polymer for friction alignment films on a substrate, rotating a roller wound with a cloth made of rayon or cotton at a constant speed and distance between the roller and the substrate, and rubbing the surface of the film containing the polymer for friction alignment films in a specified direction (friction method).

[0216] Examples of polymers used in the aforementioned friction alignment film include polyimide. The friction alignment film may contain one or more polymers for the friction alignment film.

[0217] Photo-aligned films can be obtained, for example, by forming an alignment film material containing a photo-aligned polymer with photofunctional groups on a substrate and irradiating it with polarized ultraviolet light to induce anisotropy on the surface of the film containing the photo-aligned polymer (photo-alignment method).

[0218] Examples of photo-oriented polymers include those having at least one photofunctional group selected from cyclobutyl, azophenyl, chalcone, cinnamate, coumarin, stilbene, phenolic ester, and phenylbenzoate. The photo-oriented film may contain one or more photo-oriented polymers. The photofunctional groups of the photo-oriented polymer may be present in the polymer backbone, in the polymer side chains, or in both the polymer backbone and side chains.

[0219] The type of photoreaction of the aforementioned photooriented polymers is not particularly limited, but preferred examples include photodecomposition polymers, photorearrangement polymers (preferably photoFrys rearrangement polymers), photoisomerization polymers, photodimerization polymers, and photocrosslinking polymers. Any one of these polymers can be used alone, or two or more can be used simultaneously. From the viewpoint of orientation stability, photodecomposition polymers and photorearrangement polymers with a reaction wavelength (main sensitivity wavelength) around 254 nm are particularly preferred. Furthermore, photoisomerization polymers and photodimerization polymers having photofunctional groups on their side chains are also preferred.

[0220] The main chain structure of the aforementioned photooriented polymers is not particularly limited, but as preferred examples, polyamic acid structure, polyimide structure, poly(meth)acrylic acid structure, polysiloxane structure, polyethylene structure, polystyrene structure, and polyvinyl structure can be cited.

[0221] The first alignment film 410 and the second alignment film 420 are either horizontally aligned films in which the liquid crystal component 320 is aligned parallel to the surface of the alignment film, or vertically aligned films in which the liquid crystal component 320 is aligned perpendicular to the surface of the alignment film. Preferably, the first alignment film 410 and the second alignment film 420 are horizontally aligned films. This configuration effectively balances strong scattering and low-voltage driving. More preferably, the first alignment film 410 and the second alignment film 420 are horizontally aligned films, and the liquid crystal component 320 has positive dielectric anisotropy. This configuration further effectively balances strong scattering and low-voltage driving.

[0222] When the first alignment film 410 and the second alignment film 420 are horizontal alignment films, when the applied voltage to the polymer-dispersed liquid crystal 300 is less than the threshold voltage (including the absence of applied voltage), the long axis of the liquid crystal component 320 is controlled to be oriented in the horizontal direction relative to the first alignment film 410 and the second alignment film 420, mainly by the action of the first alignment film 410 and the second alignment film 420.

[0223] That is, when no voltage is applied, the liquid crystal component 320 is horizontally oriented (uniformly oriented) relative to the first substrate 100. The orientation of the liquid crystal component 320 changes according to the electric field generated within the polymer-dispersed liquid crystal 300 due to the voltage applied between the pixel electrode 120 and the common electrode 220, thereby enabling control over the amount of light transmitted through the polymer-dispersed liquid crystal 300. When no voltage is applied between the pixel electrode 120 and the common electrode 220, the liquid crystal component 320 is horizontally oriented due to the restraining forces of the first alignment film 410 and the second alignment film 420. When a voltage is applied between the pixel electrode 120 and the common electrode 220, it rotates according to the longitudinal electric field generated within the polymer-dispersed liquid crystal 300.

[0224] Here, "the major axis of the liquid crystal component 320 is oriented horizontally relative to the first alignment film 410 and the second alignment film 420" means that the tilt angle (including the pretilt angle) of the liquid crystal component 320 relative to the first alignment film 410 and the second alignment film 420 is 0 to 5°, preferably 0 to 3°, and more preferably 0 to 1°. The tilt angle of the liquid crystal component 320 refers to the angle at which the major axis (optical axis) of the liquid crystal component 320 is tilted relative to the surfaces of the first alignment film 410 and the second alignment film 420.

[0225] When the first alignment film 410 and the second alignment film 420 are vertically aligned films, when the applied voltage to the polymer-dispersed liquid crystal 300 is less than the threshold voltage (including the absence of applied voltage), the long axis of the liquid crystal molecules is oriented vertically relative to the first alignment film 410 and the second alignment film 420, mainly through the action of the first alignment film 410 and the second alignment film 420.

[0226] That is, when no voltage is applied, the liquid crystal component 320 is vertically oriented relative to the first substrate 100. Based on the electric field generated within the polymer-dispersed liquid crystal 300 due to the voltage applied between the pixel electrode 120 and the common electrode 220, the orientation of the liquid crystal component 320 changes, thereby enabling control over the amount of light transmitted through the polymer-dispersed liquid crystal 300. When no voltage is applied between the pixel electrode 120 and the common electrode 220, the liquid crystal component 320 is vertically oriented due to the restraining forces of the first alignment film 410 and the second alignment film 420. When a voltage is applied between the pixel electrode 120 and the common electrode 220, it rotates based on the longitudinal electric field generated within the polymer-dispersed liquid crystal 300.

[0227] Here, the fact that the long axis of the liquid crystal component 320 is perpendicular to the first alignment film 410 and the second alignment film 420 means that the tilt angle (including the pretilt angle) of the liquid crystal component 320 relative to the first alignment film 410 and the second alignment film 420 is 86 to 90°, preferably 87 to 89°, and more preferably 87.5 to 89°.

[0228] Next, a method for manufacturing the first liquid crystal panel 11 according to this embodiment will be described. The method for manufacturing the first liquid crystal panel 11 includes: an alignment film forming step, in which a first alignment film 410 and a second alignment film 420, which have been subjected to alignment treatment, are formed on one side of a first substrate 100 and a second substrate 200, respectively; an injection step, in which the first alignment film 410 and the second alignment film 420 are arranged opposite to each other with the first substrate 100 and the second substrate 200 facing each other, and a composition containing liquid crystal component 320, the above-mentioned photopolymerizable liquid crystal compound and a polymerization initiator are injected between the first substrate 100 and the second substrate 200; and a light irradiation step, in which the above-mentioned composition is irradiated with light to cure the above-mentioned photopolymerizable liquid crystal compound and form a polymer network 310.

[0229] The first substrate 100 and the second substrate 200 can be manufactured using methods commonly used in the field of liquid crystal display devices.

[0230] In the above-described alignment film formation process, alignment film materials are coated onto the first substrate 100 and the second substrate 200 respectively to form a first alignment film 410 and a second alignment film 420. Examples of coating methods for the alignment film material include inkjet printing and roller coating. Next, the first alignment film 410 and the second alignment film 420 undergo alignment processing. Examples of alignment processing include friction processing (rubbing the surface of the alignment film with a roller, etc.) and photoalignment processing (irradiating the surface of the alignment film with light). Photoalignment processing allows alignment to be performed without contacting the surface of the alignment film; therefore, unlike friction processing, it has the advantage of suppressing the generation of dirt, dust, etc., during alignment processing. Alignment films that undergo alignment processing via photoalignment are also called photoalignment films.

[0231] The first orientation film 410 and the second orientation film 420 can be rubbed in a manner that makes them anti-parallel or parallel.

[0232] In the above-described implantation process, the first substrate 100 and the second substrate 200 are arranged opposite each other with the first alignment film 410 and the second alignment film 420 inside each other, and a composition containing liquid crystal component 320, photopolymerizable liquid crystal compound, and polymerization initiator is implanted between the first substrate 100 and the second substrate 200. During the implantation process, the liquid crystal molecules on the first alignment film 410 side are aligned along the alignment processing direction of the first alignment film 410, and the liquid crystal molecules on the second alignment film 420 side are aligned along the alignment processing direction of the second alignment film 420. The liquid crystal molecules located between the first alignment film 410 and the second alignment film 420 continuously change their orientation between the first alignment film 410 and the second alignment film 420.

[0233] There are no particular limitations on the polymerization initiator, and conventionally known polymerization initiators can be used. Examples of polymerization initiators that can be used include Omnirad 184 (registered trademark) (manufactured by IGM Resins.BV) represented by the following chemical formula (IN1) and OXE03 (manufactured by BASF) represented by the following chemical formula (IN2).

[0234] [Chemical Formula 4]

[0235]

[0236] [Chemical Formula 5]

[0237]

[0238] Preferably, the weight ratio of liquid crystal component 320 to photopolymerizable liquid crystal compound in the above composition is 90:10 to 97:3. That is, preferably, the weight ratio of liquid crystal component 320 is 90 or more and 97 or less. When the weight ratio of liquid crystal component 320 is 90 or more, the weight ratio of photopolymerizable liquid crystal compound is 10 or less, and when the weight ratio of liquid crystal component 320 is 97 or less, the weight ratio of photopolymerizable liquid crystal compound is 3 or more. By adopting such an arrangement, strong scattering and low-voltage driving can be effectively balanced. When the weight ratio of photopolymerizable liquid crystal compound exceeds 10, strong scattering can be obtained, but the driving voltage becomes high. When the weight ratio of photopolymerizable liquid crystal compound is less than 3, although the driving voltage is suppressed, strong scattering is sometimes not obtained.

[0239] In the aforementioned light irradiation process, the photopolymerizable liquid crystal compound is cured by irradiating the composition with light, forming a polymer network 310. Here, in the aforementioned injection process, when the liquid crystal molecules are aligned, the photopolymerizable liquid crystal compound is a liquid crystal phase. However, in the light irradiation process, by irradiating the composition with light, the photopolymerizable liquid crystal compound is cured due to a photopolymerization reaction, thereby being immobilized while maintaining its original orientation to form the polymer network 310, which cannot respond to an electric field. Therefore, even if a voltage is subsequently applied, the orientation direction of the polymer network 310 composed of the cured photopolymerizable liquid crystal compound will not align with the direction of the electric field. On the other hand, since the orientation state of the liquid crystal component 320 is not immobilized, its orientation direction will align with the direction of the electric field when a voltage is applied.

[0240] Therefore, when no voltage is applied, the orientation directions of the polymer network 310 and the liquid crystal component 320 are aligned with the direction parallel to the first substrate 100 and the second substrate 200. In this state, by making their refractive indices consistent, the first liquid crystal panel 11 becomes transparent. Furthermore, when a power supply is connected between the pixel electrode 120 and the common electrode 220 and a voltage is applied to the polymer-dispersed liquid crystal 300, the orientation direction of the liquid crystal component 320 aligns with the electric field direction. Therefore, at the interface between the liquid crystal component 320 and the polymer network 310, due to the inconsistency in refractive indices, a light-scattering state occurs, and the first liquid crystal panel 11 becomes a white, cloudy state (scattering state).

[0241] The type of light used in the above-described light irradiation process is not particularly limited; for example, ultraviolet light can be used. Examples of ultraviolet light include light with a peak wavelength in the band between 340 nm and 390 nm.

[0242] In the above-mentioned light irradiation process, it is preferable to irradiate the above-mentioned composition with 5mW / cm². 2 Above and 50mW / cm 2 The following illuminance is used. This is achieved by setting the illuminance to 5 mW / cm². 2 The above allows for more complete scattering by setting the illuminance to 50 mW / cm². 2 The following methods can suppress the temperature rise during irradiation, thereby suppressing the deterioration of production yield and the deviation of characteristics.

[0243] In the above-described light irradiation process, it is preferable to irradiate the composition with 0.5 J / cm². 2 Above and 5J / cm 2 The following irradiation levels are used. The irradiation level is set to 0.5 J / cm². 2The above allows the polymerization reaction of the photopolymerizable liquid crystal compound to proceed fully, reducing unreacted photopolymerizable liquid crystal compound and forming a polymer network 310. As a result, the hysteresis or image retention characteristics of the first liquid crystal panel 11 can be improved. Furthermore, by setting the irradiation dose to 5 J / cm²... 2 The following can improve the production cycle time.

[0244] Next, the image display method of the first liquid crystal panel will be described. Preferably, the first liquid crystal panel 11 displays images in field-sequential color (FSC) mode, such as... Figure 1 As shown, the first light source 31X includes multiple light-emitting elements (a red LED (light-emitting diode) 31R, a green LED 31G, and a blue LED 31B) that emit light of different colors. Generally, in a liquid crystal display (LCD) device that displays in color, a pixel is divided into three sub-pixels: a red pixel with a color filter that allows red light to pass through, a green pixel with a color filter that allows green light to pass through, and a blue pixel with a color filter that allows blue light to pass through. Color display can be achieved using the color filters provided in these three sub-pixels, but approximately two-thirds of the backlight light illuminating the liquid crystal panel is absorbed by the color filters. Therefore, LCD devices using color filters suffer from low light utilization efficiency. On the other hand, by displaying images in FSC mode, the first light source 31X has multiple light-emitting elements that emit light of different colors, enabling color display without the use of color filters. Compared to LCD devices using color filters, this improves light utilization efficiency, further increases the brightness of the first liquid crystal panel 11, and achieves low power consumption. Furthermore, since no color filter is required, the liquid crystal display device 1 can be made thinner.

[0245] In the first liquid crystal panel 11 that displays images in FSC mode, one frame, which is the display period of one image, is divided into multiple fields. Furthermore, a field is also called a subframe, but the term "field" will be used consistently in the following description. For example, one frame is divided into: a field displaying a red image based on the red component of the input image signal (red field); a field displaying a green image based on the green component of the input image signal (green field); and a field displaying a blue image based on the blue component of the input image signal (blue field). By displaying the primary colors one by one as described above, a color image is displayed on the liquid crystal panel.

[0246] Thus, in the first liquid crystal panel 11 displaying images in FSC mode, since the frame period is divided into multiple fields and different colors are displayed for each field, a color filter for color display is not required. Therefore, in the FSC-mode liquid crystal display device 1, the light utilization efficiency is approximately three times that of a color filter-mode liquid crystal display device. Consequently, the FSC-mode liquid crystal display device is suitable for high brightness or low power consumption.

[0247] Figure 3 This is a block diagram showing the overall configuration of the liquid crystal display device according to Embodiment 1. The liquid crystal display device 1 of this embodiment includes a preprocessing unit 1000, a timing controller 2000, a gate driver 3100, a source driver 3200, an LED driver 3300, a first liquid crystal panel 11, and a first light source 31X. Alternatively, the gate driver 3100 or the source driver 3200, or both, may be disposed within the first liquid crystal panel 11. Furthermore, in... Figure 3 The description of the second liquid crystal panel 12 is omitted. However, the second liquid crystal panel 12 is not a liquid crystal panel that displays images in the FSC mode. Instead, it is a conventional liquid crystal panel that uses a color filter provided on the second liquid crystal panel 12 and a backlight provided on the back side of the second liquid crystal panel 12 for color display. Apart from this, the second liquid crystal panel 12 has the same structure as the first liquid crystal panel 11.

[0248] The first liquid crystal panel 11 includes a display unit 11A for displaying images. The preprocessing unit 1000 includes a signal separation circuit 1100, a data correction circuit 1200, a red field memory 1300(R), a green field memory 1300(G), and a blue field memory 1300(B).

[0249] In this embodiment, the first light source 31X employs multiple LEDs (light-emitting diodes) as the aforementioned multiple light-emitting elements. Specifically, as... Figure 1 As shown, the first light source 31X is composed of red LED 31R, green LED 31G, and blue LED 31B. Furthermore, in this embodiment, the liquid crystal panel driving unit is implemented by a timing controller 2000, a gate driver 3100, and a source driver 3200, and the light source driving unit is implemented by an LED driver 3300. Additionally, the input image data separation unit is implemented by a signal separation circuit 1100.

[0250] Figure 4This diagram illustrates the configuration of one frame period in the liquid crystal display device according to Embodiment 1. One frame period is divided into: a red field, where a red image is displayed based on the red component of the input image signal DIN; a green field, where a green image is displayed based on the green component of the input image signal DIN; and a blue field, where a blue image is displayed based on the blue component of the input image signal DIN. In the red field, after a predetermined period elapses from the start time of the field, the red LED 31R becomes lit. In the green field, after a predetermined period elapses from the start time of the field, the green LED 31G becomes lit. In the blue field, after a predetermined period elapses from the start time of the field, the blue LED 31B becomes lit.

[0251] During the operation of the liquid crystal display device 1, these red, green, and blue fields are repeated. Thus, the red, green, and blue images are repeatedly displayed, showing the desired color image on the display unit 11A. Furthermore, the order of the fields is not particularly limited. For example, the order could be "blue field, green field, red field". Additionally, the length of the period during which the LEDs are lit in each field can be determined based on considerations of the liquid crystal's response characteristics.

[0252] like Figure 3 As shown, the display unit 11A is provided with multiple (n) source lines (image signal lines) SL1 to SLn and multiple (m) gate lines (scan signal lines) GL1 to GLm. Pixel forming units 4, which form pixels, are provided at each intersection of the source lines SL1 to SLn and the gate lines GL1 to GLm. That is, the display unit 11A includes multiple (n × m) pixel forming units 4. These multiple pixel forming units 4 are arranged in a matrix, forming an m-row × n-column pixel matrix. Hereinafter, the source lines SL1 to SLn will be simply referred to as source lines SL, and the gate lines GL1 to GLm will be simply referred to as gate lines GL.

[0253] Each pixel forming unit 4 includes: a TFT (thin-film transistor) 40, which is a switching element, with its gate terminal connected to a gate line GL passing through a corresponding intersection point, and its source terminal connected to a source line SL passing through the intersection point; a pixel electrode 120, which is connected to the drain terminal of the TFT 40; a common electrode 220 and an auxiliary capacitor electrode 45, which are shared by the aforementioned plurality of pixel forming units 4; a liquid crystal capacitor 42, which is formed by the pixel electrode 120 and the common electrode 220; and an auxiliary capacitor 43, which is formed by the pixel electrode 120 and the auxiliary capacitor electrode 45. The liquid crystal capacitor 42 and the auxiliary capacitor 43 constitute the pixel capacitor 46. Furthermore, in Figure 3 The display section 11A shows only the constituent elements corresponding to the 1 pixel forming section 4.

[0254] Next, an explanation Figure 3 The operation of the components shown is as follows. The signal separation circuit 1100 within the preprocessing unit 1000 separates the input image signal DIN transmitted from the outside into red input grayscale data 1R, green input grayscale data 1G, and blue input grayscale data 1B. The data correction circuit 1200 within the preprocessing unit 1000 corrects the input grayscale data (red input grayscale data 1R, green input grayscale data 1G, and blue input grayscale data 1B) output from the signal separation circuit 1100 into data corresponding to the voltage applied to the liquid crystal panel 11, and outputs the corrected data as applied grayscale data (applied grayscale data 1r for the red field, applied grayscale data 1g for the green field, and applied grayscale data 1b for the blue field). A detailed description of the data correction circuit 1200 will be provided later.

[0255] The red field memory 1300(R), green field memory 1300(G), and blue field memory 1300(B) respectively store applied grayscale data 1r for the red field, applied grayscale data 1g for the green field, and applied grayscale data 1b for the blue field, which are output from the data correction circuit 1200.

[0256] The timing controller 2000 reads grayscale data 1r for the red field, grayscale data 1g for the green field, and grayscale data 1b for the blue field from the red field memory 1300(R), the green field memory 1300(G), and the blue field memory 1300(B), respectively, and outputs a digital image signal DV, a gate start pulse signal GSP and a gate clock signal GCK for controlling the operation of the gate driver 3100, a source start pulse signal SSP, a source clock signal SCK and a latch strobe signal LS for controlling the operation of the source driver 3200, and an LED driver control signal S1 for controlling the operation of the LED driver 3300.

[0257] The gate driver 3100 applies an active scan signal to each gate line GL repeatedly over a period of one vertical scan, based on the gate start pulse signal GSP and the gate clock signal GCK transmitted from the timing controller 2000.

[0258] The source driver 3200 receives a digital image signal DV, a source start pulse signal SSP, a source clock signal SCK, and a latch strobe signal LS from the timing controller 2000, and applies a driving image signal to each source line SL. At this time, in the source driver 3200, during the timing of generating the pulse of the source clock signal SCK, the digital image signal DV, representing the voltage to be applied to each source line SL, is held sequentially. Furthermore, during the timing of generating the pulse of the latch strobe signal LS, the held digital image signal DV is converted into an analog voltage. This converted analog voltage is applied simultaneously as a driving image signal to all source lines SL1 to SLn.

[0259] The LED driver 3300 outputs a light source control signal S2 based on the LED driver control signal S1 transmitted from the timing controller 2000, for controlling the state of each LED (red LED 31R, green LED 31G, and blue LED 31B) constituting the first light source 31X. In the first light source 31X, the state of each LED (switching between on and off states) is appropriately switched based on the light source control signal S2. Furthermore, in this embodiment, as... Figure 4 Switch the state of each LED as shown.

[0260] As described above, a scan signal is applied to the gate lines GL1 to GLm, and a driving image signal is applied to the source lines SL1 to SLn. The state of each LED is switched appropriately, and thus, an image corresponding to the input image signal DIN is displayed on the display section 11A of the liquid crystal panel 11.

[0261] The first light source 31X includes multiple light-emitting elements (red LED 31R, green LED 31G, and blue LED 31B) that emit light of different colors. The first light source 31X may have, for example, a rod-shaped form in which the multiple light-emitting elements are arranged in a straight line.

[0262] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], the distance between the first liquid crystal panel 11 and the first light source 31X is set to h11 [cm], and the incident angle of the light from the first light source 31X onto the main surface 11P on the back side of the first liquid crystal panel 11 is set to θ11 [°], the liquid crystal display device 1 preferably satisfies the following (Equation 1-1). By setting it in this way, the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state, and enable a brighter display. In addition, in this specification, the distance between the first liquid crystal panel and the light source refers to the distance from the first liquid crystal panel to the end of the first liquid crystal panel side of the light source. In addition, θ11 refers to the incident angle of the light emitted from the light source 31X that passes through the center of the first liquid crystal panel 11.

[0263] 1≤h11≤{a / (tanθ11)}…(Formula 1-1)

[0264] like Figure 1 As shown, the first light source 31X is disposed corresponding to one of the two opposing end portions 11X and 11Y of the first liquid crystal panel 11. The liquid crystal display device 1 also provides a second light source 31Y between the first liquid crystal panel 11 and the second liquid crystal panel 12. The second light source 31Y is disposed corresponding to the other end portion 11Y of the pair of end portions 11X and 11Y. The second light source 31Y illuminates the main surface 11P on the back side of the first liquid crystal panel 11 from an inclined direction. The incident angle θ11 of the light from the first light source 31X on the main surface 11P on the back side of the first liquid crystal panel 11 is the same as the incident angle θ12 of the light from the second light source 31Y on the main surface 11P on the back side of the first liquid crystal panel 11. By adopting this arrangement, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0265] The second light source 31Y is the same as the first light source 31X, except that it is located on the other end side portion 11Y.

[0266] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], the distance between the first liquid crystal panel 11 and the second light source 31Y is set to h12 [cm], and the incident angle of the light from the second light source 31Y onto the main surface 11P on the back side of the first liquid crystal panel 11 is set to θ12 [°], the liquid crystal display device 1 preferably satisfies the following (Equations 1-2). By setting it in this way, the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state, and enable a brighter display. In addition, θ12 refers to the incident angle of the light emitted from the light source 31Y that passes through the light closest to the center of the first liquid crystal panel 11.

[0267] 1≤h12≤{a / (tanθ12)}…(Equation 1-2)

[0268] Preferably, the first light source 31X and the second light source 31Y satisfy the following equations (Equations 1-3) and (Equations 1-4). By configuring the light source 31X and the second light source 31Y in such a way that the light is symmetrically incident on the center line of the first liquid crystal panel 11 which is parallel to the pair of end edge portions 11X and 11Y, the decrease in brightness can be suppressed more uniformly within the panel surface in the scattering state.

[0269] h11=h12…(Equation 1-3)

[0270] θ11=θ12…(Equation 1-4)

[0271] Preferably, the first light source 31X and the second light source 31Y are arranged in a linearly symmetrical configuration with respect to the center line of the first liquid crystal panel 11, which is parallel to the pair of end edge portions 11X and 11Y, when viewed from the front. By configuring it in this way, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0272] Preferably, h11 and h12, as well as θ11 and θ12, are set such that light from the first light source 31X and light from the second light source 31Y reach the center line of the first liquid crystal panel 11, which is parallel to the pair of end edge portions 11X and 11Y. By configuring it in this way, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0273] When the first liquid crystal panel 11 is 19 inches, h11 and h12 are preferably 3 cm or more and 12 cm or less, more preferably 4 cm or more and 11 cm or less, and even more preferably 5 cm or more and 10 cm or less. In addition, θ11 and θ12 are preferably 51° or more and 63° or less, more preferably 53° or more and 61° or less, and even more preferably 55° or more and 59° or less.

[0274] Next, the second liquid crystal panel 12 will be described. In the liquid crystal display device 1 of this embodiment, when the first liquid crystal panel 11 is in a transparent state, the image of the second liquid crystal panel 12 can be visually recognized from the viewing surface side.

[0275] Figure 5 This is a cross-sectional schematic diagram of the second liquid crystal panel included in the liquid crystal display device of Embodiment 1. Figure 5 As shown, the second liquid crystal panel 12, from the back side towards the viewing side, sequentially comprises: a first polarizing plate 510, a third substrate 600, a third alignment film 710, a liquid crystal layer 800 containing liquid crystal molecules, a fourth alignment film 720, a fourth substrate 900, and a second polarizing plate 520. The third substrate 600 has a third support substrate 610 and a plurality of pixel electrodes 620. The fourth substrate 900 has a fourth support substrate 910, a color filter layer 920, and a common electrode 930.

[0276] In this embodiment, a liquid crystal display device with a vertical alignment mode, where the third substrate 600 has a pixel electrode 620 and the fourth substrate 900 has a common electrode 930, is described. However, the display mode of the second liquid crystal panel 12 is not limited to this; a liquid crystal display device with a horizontal alignment mode, where both the pixel electrode and the common electrode are provided on the third substrate 600 or the fourth substrate 900, can also be described. A vertical alignment mode refers to a mode in which liquid crystal molecules are aligned in a substantially vertical direction relative to the main surfaces of a pair of substrates (the first substrate and the second substrate) when no voltage is applied to the liquid crystal layer. Examples include VA (Vertical Alignment) mode and TN (Twisted Nematic) mode. Conversely, a horizontal alignment mode refers to a mode in which liquid crystal molecules are aligned in a substantially horizontal direction relative to the main surfaces of a pair of substrates when no voltage is applied to the liquid crystal layer. Examples include IPS (In-Plane Switching) mode and FFS (Fringe Field Switching) mode.

[0277] Furthermore, "approximately vertical" refers to a pretilt angle of the liquid crystal molecules relative to the principal surfaces of each substrate that is 85° or higher and 90° or lower. "Approximately horizontal" refers to a pretilt angle of the liquid crystal molecules relative to the principal surfaces of each substrate that is 0° or higher and 5° or lower. The pretilt angle is the angle formed by the long axis of the liquid crystal molecules relative to the surface of the substrate when a voltage less than a threshold voltage (including when no voltage is applied) is applied to the liquid crystal layer. The substrate surface is set to 0°, and the substrate normal is set to 90°. The principal surface of the substrate refers to the substrate surface.

[0278] In this embodiment, light from the backlight 50 is incident on the second liquid crystal panel 12, and the orientation of the liquid crystal molecules in the liquid crystal layer 800 is switched, thereby controlling the amount of light transmitted through the second liquid crystal panel 12. The second liquid crystal panel 12 is a liquid crystal display (LCD) panel.

[0279] Preferably, the third support substrate 610 and the fourth support substrate 910 are transparent substrates, such as glass substrates and plastic substrates.

[0280] The pixel electrode 620 is the same as the pixel electrode 120 of the first liquid crystal panel 11, and the common electrode 930 is the same as the common electrode 220 of the first liquid crystal panel 11.

[0281] The color filter layer 920 is composed of a red color filter, a green color filter, and a blue color filter. Each pixel has three image elements arranged in a strip shape: an image element with a red color filter, an image element with a green color filter, and an image element with a blue color filter.

[0282] Red, green, and blue color filters are made, for example, of transparent resin containing pigments. Typically, a combination of red, green, and blue color filters is configured in all pixels. By controlling the amount of colored light transmitted through the red, green, and blue color filters and mixing them, the desired color is obtained in each pixel.

[0283] The third alignment film 710 and the fourth alignment film 720 have the function of controlling the orientation of liquid crystal molecules in the liquid crystal layer 800. When the applied voltage to the liquid crystal layer 800 is less than the threshold voltage (including when no voltage is applied), the orientation of liquid crystal molecules in the liquid crystal layer 800 is mainly controlled by the function of the alignment film. As the material of the alignment film, polymers containing polyimide in the main chain, polymers containing polyamic acid in the main chain, polymers containing polysiloxane in the main chain, and other materials commonly used in the field of liquid crystal display panels can be used.

[0284] The liquid crystal layer 800 contains liquid crystal material. By applying a voltage to the liquid crystal layer 800, the orientation state of the liquid crystal molecules in the liquid crystal material is changed according to the applied voltage, thereby controlling the amount of light transmitted.

[0285] Liquid crystal molecules can be liquid crystal molecules with a positive value of dielectric constant anisotropy (Δε) as defined by the above formula (L), or liquid crystal molecules with a negative value of dielectric constant anisotropy (Δε).

[0286] The orientation switching of liquid crystal molecules is achieved by applying voltage to the liquid crystal layer 800 by multiple pixel electrodes 620 and a common electrode 930. In the unapplied voltage state, where no voltage is applied between the pixel electrodes 620 and the common electrode 930, the initial orientation of the liquid crystal molecules is constrained by the third alignment film 710 and the fourth alignment film 720. Furthermore, the unapplied voltage state, where no voltage is applied between the pixel electrodes 620 and the common electrode 930, includes a state where no voltage is substantially applied between the pixel electrodes 620 and the common electrode 930, referring to a state where the applied voltage to the liquid crystal layer 800 is less than a threshold value.

[0287] The second liquid crystal panel 12 may also have polarizing plates on the side of the third substrate 600 and the fourth substrate 900 opposite to the liquid crystal layer 800. Preferably, the polarizing plates are all absorption polarizers, arranged in an orthogonal nicotle configuration with their absorption axes orthogonal to each other. Furthermore, it is preferable that the liquid crystal molecules in the liquid crystal layer 800 are uniformly oriented in a direction parallel to the absorption axis of any one of the polarizing plates when no voltage is applied. With this configuration, the liquid crystal panel 12 achieves a normally black mode.

[0288] The backlight 50 can be any backlight that illuminates the second liquid crystal panel 12, and there are no particular limitations. As the backlight 50, a backlight commonly used in the field of liquid crystal display devices can be used. The backlight 50 can be disposed on the back of the second liquid crystal panel 12 so that the light generated by the backlight 50 is transmitted through the transmission area of ​​the second liquid crystal panel 12 and emitted to the observer side. It can be a direct-lit type or an edge-lit type.

[0289] The backlight 50 includes, for example, a light source and a light guide plate. The light source is any light source that emits light including visible light; there are no particular limitations. It can be a light source that emits only visible light, or a light source that emits both visible and ultraviolet light. For color display by the second liquid crystal panel 12, a light source emitting white light is suitable. For example, cold cathode fluorescent lamps (CCFLs) and light-emitting diodes (LEDs) are suitable types of light sources. The light guide plate only needs to have the function of uniformly emitting light incident from the end face; light guide plates commonly used in the field of liquid crystal display devices can be used. Furthermore, in this specification, "visible light" refers to light (electromagnetic waves) with a wavelength of 380 nm or more and less than 800 nm. The backlight 50 can also appropriately use optical sheets such as diffusers and prism sheets.

[0290] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], it is preferable that the distance b [cm] between the first liquid crystal panel 11 and the second liquid crystal panel 12 is a [cm] or less. By adopting this configuration, the liquid crystal display device 1 can be made thinner. Furthermore, since the image positions of the first liquid crystal panel 11 and the second liquid crystal panel 12 can be brought closer together, a unified presentation can be achieved when visually recognizing the liquid crystal display device 1 from an angle. This is suitable, for example, for displaying text information on the first liquid crystal panel 11 and the second liquid crystal panel 12.

[0291] It is also preferable that the distance b [cm] between the first liquid crystal panel 11 and the second liquid crystal panel 12 exceeds a [cm]. By setting it in this way, the image positions of the first liquid crystal panel 11 and the second liquid crystal panel 12 can be far apart, so that when visual recognition is performed on the liquid crystal display device 1 from the tilt direction, a more spatial depth can be presented.

[0292] When the first LCD panel 11 is 19 inches and the second LCD panel is 17 inches, it is preferable that a = 40 cm, b is preferably 10 cm or more and 20 cm or less, more preferably 11 cm or more and 19 cm or less, and even more preferably 12 cm or more and 18 cm or less.

[0293] As described above, the liquid crystal display device 1 of this embodiment is a dual display (PDLC panel + LCD panel) with the front panel (first liquid crystal panel 11) set as a PDLC panel and the rear panel (second liquid crystal panel 12) set as an LCD panel. By tilting the light source driven in the FSC mode to illuminate the PDLC panel, it is possible to achieve a display device that can take into account good transparency (50% or more), large size (e.g., 19-inch size) and bright display (high brightness).

[0294] In addition to the components described above, the liquid crystal display device 1 of this embodiment also includes external circuits such as TCP (bandwidth package) and PCB (printed wiring board), optical films such as viewing angle enhancement film and brightness enhancement film, and an outer frame, etc. Depending on the components, they may also be incorporated into other components. There are no particular limitations on components other than those already described; components commonly used in the field of liquid crystal display devices can be used, therefore, their description is omitted.

[0295] (Implementation Method 2)

[0296] This embodiment mainly describes the features unique to this embodiment, and omits the description of content that is repeated in Embodiment 1. This embodiment is substantially the same as Embodiment 1, except that it has a back-side light source between the first light source 31X and the second liquid crystal panel 12.

[0297] Figure 6 This is a cross-sectional schematic diagram of the liquid crystal display device according to Embodiment 2. Figure 6 As shown, the liquid crystal display device 1 of this preferred embodiment preferably includes a first back-side light source 32X serving as the aforementioned back-side light source between the first light source 31X and the second liquid crystal panel 12. The first back-side light source 32X illuminates the main surface 11P on the back side of the first liquid crystal panel 11 from an oblique direction. By adopting this configuration, the decrease in brightness (more specifically, front brightness) of the central portion of the panel in a scattered state can be further suppressed. As a result, the display screen can be further enlarged.

[0298] Preferably, the first rear-side light source 32X, like the first light source 31X, includes multiple light-emitting elements (red LED 31R, green LED 31G, and blue LED 31B) that emit light of different colors. The first rear-side light source 32X may have, for example, a rod-shaped form in which the aforementioned multiple light-emitting elements are arranged in a straight line.

[0299] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], the distance between the first liquid crystal panel 11 and the first light source 31X is set to h11 [cm], the incident angle of the light from the first light source 31X on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ11 [°], and the incident angle of the light from the first back side light source 32X on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ21 [°], it is preferable to satisfy the following (Equation 1-1) and (Equation 2-1). By setting it in this way, the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state, and enable a brighter display. In addition, θ21 refers to the incident angle of the light emitted from the light source 32X that passes through the center of the first liquid crystal panel 11.

[0300] 1≤h11≤{a / (tanθ11)}…(Formula 1-1)

[0301] θ11-θ21>10°…(Equation 2-1)

[0302] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], the distance between the first liquid crystal panel 11 and the second light source 31Y is set to h12 [cm], the incident angle of the light from the second light source 31Y on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ12 [°], and the incident angle of the light from the second back side light source 32Y on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ22 [°], it is preferable to satisfy the following (Equations 1-2) and (Equations 2-2). By setting it in this way, the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state, and enable a brighter display. In addition, θ22 refers to the incident angle of the light emitted from the light source 32Y that passes through the center of the first liquid crystal panel 11.

[0303] 1≤h12≤{a / (tanθ12)}…(Equation 1-2)

[0304] θ12-θ22>10°…(Equation 2-2)

[0305] like Figure 6As shown, the first back-side light source 32X is disposed corresponding to one of the pair of opposing end portions 11X and 11Y of the first liquid crystal panel 11. The liquid crystal display device 1 also provides a second back-side light source 32Y between the first liquid crystal panel 11 and the second liquid crystal panel 12. The second back-side light source 32Y is disposed corresponding to the other end portion 11Y of the pair of end portions 11X and 11Y. The second back-side light source 32Y illuminates the main surface 11P of the back side of the first liquid crystal panel 11 from an inclined direction. The incident angle θ21 of the light from the first back-side light source 32X on the main surface 11P of the back side of the first liquid crystal panel 11 is the same as the incident angle θ22 of the light from the second back-side light source 32Y on the main surface 11P of the back side of the first liquid crystal panel 11. By adopting this arrangement, under scattering conditions, the decrease in brightness can be suppressed more uniformly within the panel surface.

[0306] The second rear-side light source 32Y is the same as the first rear-side light source 32X, except that it is located on the other end portion 11Y.

[0307] When the length of the long side of the first liquid crystal panel 11 is set to 2a [cm], the distance between the first liquid crystal panel 11 and the second light source 31Y is set to h12 [cm], the incident angle of the light from the second light source 31Y on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ12 [°], and the incident angle of the light from the second back side light source 32Y on the main surface 11P of the back side of the first liquid crystal panel 11 is set to θ22 [°], it is preferable to satisfy the following (Equation 1-2) and (Equation 2-2). By setting it in this way, the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state, and enable a brighter display.

[0308] 1≤h12≤{a / (tanθ12)}…(Equation 1-2)

[0309] θ12-θ22>10°…(Equation 2-2)

[0310] When the distance between the first liquid crystal panel 11 and the first back-side light source 32X is set to h21 [cm], and the distance between the first liquid crystal panel 11 and the second back-side light source 32Y is set to h22 [cm], the first preferred back-side light source 32X and the second back-side light source 32Y satisfy the following equations (Equation 2-3) and (Equation 2-4). By configuring it in this way, the light from the first back-side light source 32X and the second back-side light source 32Y will be symmetrically illuminated relative to the center line of the first liquid crystal panel 11 which is parallel to the pair of end edge portions 11X and 11Y. Therefore, in the scattered state, the decrease in brightness can be suppressed more uniformly within the panel surface.

[0311] h21=h22…(Equation 2-3)

[0312] θ21=θ22…(Equation 2-4)

[0313] Preferably, the first rear-side light source 32X and the second rear-side light source 32Y are arranged in a linearly symmetrical configuration with respect to the center line of the first liquid crystal panel 11, which is parallel to the pair of end edge portions 11X and 11Y, when viewed from the front. By configuring it in this way, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0314] Preferably, θ21 and θ22 are set such that light from the first rear-side light source 32X and light from the second rear-side light source 32Y reach the center line of the first liquid crystal panel 11, which is parallel to the pair of end edge portions 11X and 11Y. By configuring it in this way, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0315] Preferably, h21 and h22, as well as θ21 and θ22, are configured such that light from the first rear-side light source 32X and light from the second rear-side light source 32Y reach the center line of the first liquid crystal panel 11, which is parallel to the pair of end-edge portions 11X and 11Y. By configuring it in this way, the decrease in brightness can be suppressed more uniformly within the panel surface under scattering conditions.

[0316] When the first liquid crystal panel 11 is 19 inches, h21 and h22 are preferably 4 cm or more and 13 cm or less, more preferably 5 cm or more and 12 cm or less, and even more preferably 6 cm or more and 11 cm or less. In addition, θ21 and θ22 are preferably 62° or more and 74° or less, more preferably 64° or more and 72° or less, and even more preferably 66° or more and 70° or less.

[0317] The distance d between the first light source 31X and the first back-side light source 32X, and the distance d between the second light source 31Y and the second back-side light source 32Y are preferably 1cm or more and 6cm or less, more preferably 2cm or more and 5cm or less.

[0318] (Variation Example 1)

[0319] Figure 7 This is a cross-sectional schematic diagram of the liquid crystal display device in Modified Example 1. Figure 7 It is along Figure 6 A schematic diagram of the cross-section of line Y1-Y2 in the diagram. (See attached diagram.) Figure 7As shown, the first liquid crystal panel 11 may also have a transparent resin plate 20 on the back side of the first substrate 100. By having the first liquid crystal panel 11 have a transparent resin plate 20, the strength of the first liquid crystal panel 11 can be improved. The transparent resin plate 20 may be the same size as the first support substrate 110 or may be larger than the first support substrate 110. For example, an acrylic sheet can be used as the transparent resin plate 20.

[0320] (Variation Example 2)

[0321] Figure 8 This is a cross-sectional schematic diagram of the liquid crystal display device in Modified Example 2. Figure 8 As shown, the liquid crystal display device 1 may also have a light-shielding grille 13 on the viewing surface side of the first liquid crystal panel 11. With this arrangement, when the liquid crystal display device is viewed from an oblique direction, light can be shielded in a way that the light source (especially the LED constituting the light source) is not visible.

[0322] Figure 9 This is a three-dimensional schematic diagram of the light-shielding grille provided in the liquid crystal display device of Modified Example 2. For example... Figure 9 As shown, the light-shielding grid 13 includes: a grid layer 131, wherein the light-shielding layer 1311 and the transparent layer 1312 are arranged alternately in parallel; and a pair of transparent films 132 that hold the grid layer 131. The light-shielding layer 1311 and the transparent layer 1312 may contain, for example, silicone resin.

[0323] (Variation Example 3)

[0324] Figures 10A to 10D This is an example of a cross-sectional schematic diagram of the liquid crystal display device in Modified Example 3. For example... Figures 10A to 10D As shown, the first liquid crystal panel 11 may also have an anisotropic light diffusion film 14 on at least one of the back side of the first support substrate 110 and the viewing side of the second support substrate 210. The anisotropic light diffusion film 14 has the function of allowing light to pass through when viewed from the front and scattering light when viewed at an angle. By adopting such an arrangement, the decrease in brightness of the central part of the panel in the scattering state can be further suppressed.

[0325] For example, it can be like Figure 10A As shown, in the liquid crystal display device 1 having a pair of light sources (first light source 31X and second light source 31Y), an anisotropic light diffusion film 14 is disposed on the back side of the first support substrate 110, or as shown in the diagram. Figure 10B As shown, in the liquid crystal display device 1 with a pair of light sources (first light source 31X and second light source 31Y), an anisotropic light diffusion film 14 is disposed on the observation surface side of the second support substrate 210. Alternatively, it can be as follows... Figure 10CAs shown, in the liquid crystal display device 1 having two pairs of light sources (first light source 31X and second light source 31Y, and first back-side light source 32X and second back-side light source 32Y), an anisotropic light diffusion film 14 is disposed on the back side of the first support substrate 110, or as shown in the diagram. Figure 10D As shown, in the liquid crystal display device 1 having two pairs of light sources (first light source 31X and second light source 31Y, and first back side light source 32X and second back side light source 32Y), an anisotropic light diffusion film 14 is disposed on the observation surface side of the second support substrate 210.

[0326] The anisotropic light diffusion film 14 may, for example, have the function of diffusing light when viewed from the right and left sides at an angle, or it may have the function of diffusing light when viewed from either side at an angle.

[0327] Examples of anisotropic light diffusion films 14 include the light diffusion film (a hybrid film with high and low refractive index structures) disclosed in International Publication No. 2016 / 051560 or PDLC sheets. By using such anisotropic light diffusion films 14, the light diffusion efficiency towards the front is improved. PDLC sheets are ordinary PDLCs that are in a scattering state when no voltage is applied and a transparent state when a voltage is applied, and can be made thinner compared to glass substrates. For example, PDLC films manufactured by SMARTINT Corporation can be used as PDLC sheets.

[0328] Figure 11A This is a three-dimensional schematic diagram of the anisotropic light diffusion film of the liquid crystal display device in Modified Example 3. Figure 11B This is a cross-sectional schematic diagram of the anisotropic light diffusion film in the liquid crystal display device of Modified Example 3. (Using...) Figure 11A and Figure 11B Specifically, an example of an anisotropic light diffusion film 14 is illustrated. Furthermore, Figure 11A and Figure 11B The first internal structure 4020 and the second internal structure 4030 of the anisotropic light diffusion film 14 shown are both pillar structures (4020a, 4030a), but Figure 11B This diagram is used as a general overview and is not limited to the case where the first and second internal structures (4020, 4030) are both column structures (4020a, 4030a), but also includes cases where they are other internal structures such as lattice structures.

[0329] like Figure 11A and Figure 11BAs shown, the anisotropic light diffusion film 14 is a film having a single-layer light diffusion layer 4050. In the region 4011 where the refractive index is relatively low, the light diffusion layer 4050 has a first pillar structure 4020a and a second pillar structure 4030a in sequence from bottom to top along the film thickness direction. The first pillar structure 4020a and the second pillar structure 4030a have pillars (4012a, 4012a') that serve as multiple regions (4012, 4012') with relatively high refractive index.

[0330] In addition, the column 4012a in the first column structure 4020a has a bend 4014 at the midpoint along the thickness direction of the membrane.

[0331] Figure 12 This is a three-dimensional schematic diagram of the anisotropic light diffusion film in the liquid crystal display device of Modified Example 3. Taking the case where both the first internal structure 4020 and the second internal structure 4030 are column structures (4020a, 4030a) as an example, the light diffusion characteristics of the anisotropic light diffusion film 14 will be specifically explained.

[0332] like Figure 12 As shown, the anisotropic light diffusion film 14 has a first pillar structure 4020a and a second pillar structure 4030a within the film, and a curved portion 4014 is provided in the pillar constituting the first pillar structure 4020a. Therefore, as Figure 12 As shown, by making the three light diffusion incident angle regions generated by the respective first pillar structure 4020a and second pillar structure 4030a staggered and overlapping within an appropriate range, the light diffusion incident angle region of the entire film can be effectively expanded.

[0333] Here, in the column structure, incident light with an incident angle approximately parallel to the tilt angle of the column constituting the column structure can be diffused efficiently without loss. This is because such an incident angle is contained within the light diffusion incident angle region. However, incident light with an incident angle exactly matching the tilt angle of the column may sometimes pass through without sufficient diffusion. This problem can be effectively solved by using an anisotropic light diffusion film 14.

[0334] For example, incident light with an incident angle perfectly parallel to the tilt angle of the columnar structure 4030a, as shown by arrow A, tends not to be sufficiently diffused by the second columnar structure 4030a. However, if... Figure 12 The anisotropic light diffusion film 14 shown diffuses light in two stages through a first pillar structure 4020a composed of pillars with curved portions 4014, thus enabling the light to diffuse horizontally in sufficient quantities.

[0335] Furthermore, incident light with an incident angle significantly different from the tilt angle of the columnar structure 4030a, such as the incident light indicated by arrow B, diffuses in a crescent shape only through the side of the columnar structure 4030a, tending to have insufficient diffusion at the stage of the second columnar structure 4030a. However, if... Figure 12 The anisotropic light diffusion film 14 shown can ultimately diffuse light in a sufficiently horizontal manner through the first pillar structure 4020a composed of pillars having a curved portion 4014.

[0336] Therefore, if it is an anisotropic light diffusion film 14, it can effectively expand the light diffusion incident angle region of the entire film, and effectively suppress the changes in light diffusion characteristics caused by changes in the incident angle of the incident light.

[0337] Furthermore, the explanation was based on the case where the incident light is incident from the side of the second pillar structure, but the same applies when the incident light is incident from the side of the first pillar structure. Additionally, the explanation was based on a three-stage diffusion process, but diffusion with four or more stages is also possible.

[0338] Figure 13A and Figure 13B This is an example of a cross-sectional schematic diagram of the anisotropic light diffusion film provided in the liquid crystal display device of Modification Example 3. In the above... Figure 11A , Figure 11B as well as Figure 12 The anisotropic light diffusion film 14 is illustrated using the case where both the first and second internal structures are columnar structures as an example, but there are no particular limitations on the first and second internal structures. Specifically, examples can be given... Figure 13A The scheme shown, where both the first and second internal structures are grid structures (4020b, 4030b); or Figure 13B The scheme shown is such that the first internal structure is a grid structure 4020b and the second internal structure is a column structure 4030a; or the scheme is such that the first internal structure is a column structure 4020a and the second internal structure is a grid structure 4030b, etc.

[0339] Furthermore, the difference lies in the fact that the column structure causes the incident light to diffuse isotropically (the diffused light has a roughly circular planar shape), while the grating structure causes the incident light to diffuse anisotropically (the diffused light has a linear planar shape).

[0340] like Figure 10A and Figure 10BAs shown, the second liquid crystal panel 12 of the above embodiment may also include, in sequence from the back side to the viewing side: a third support substrate 610; a liquid crystal layer 800; a fourth support substrate 910; and an anisotropic light-reflecting film 15, which has the function of allowing light to pass through when viewed from the front and reflecting light when viewed at an angle. By adopting such an arrangement, the light reuse efficiency from the backlight 50 can be improved, and the brightness of the liquid crystal display device 1 can be further improved.

[0341] Examples of anisotropic light-reflecting films 15 include dielectric multilayer mirrors and brightness-enhancing films.

[0342] Dielectric multilayer mirrors have a structure in which dielectric materials with high refractive index and dielectric materials with low refractive index are alternately stacked on a substrate. For example, TiO2 can be used as a dielectric material with high refractive index, and SiO2 as a dielectric material with low refractive index. Dielectric multilayer mirrors may have a structure in which dielectric materials with high refractive index and dielectric materials with low refractive index are alternately stacked in ten to dozens of layers. Furthermore, glass substrates or the like can be used as substrates, but are not limited to these; any substrate that is transparent to light is acceptable. Examples of dielectric multilayer mirrors include PICASUS (registered trademark) manufactured by Toray Industries, Inc.

[0343] A brightness enhancement film is an optical component that allows polarized light (light vibrating in a specified direction) to pass through and reflects other polarized light. Examples of brightness enhancement films include DBEF (a registered trademark) manufactured by 3M.

[0344] like Figure 10A and Figure 10B As shown, the liquid crystal display device 1 may also have a first mirror 61X on the viewing surface side of the second liquid crystal panel 12 and near the first light source 31X, and a second mirror 61Y on the viewing surface side of the second liquid crystal panel 12 and near the second light source 31Y. By adopting such an arrangement, the light from the first light sources 31X and 31Y can be reflected to the viewing surface side by the anisotropic light reflective film 15, thereby reusing the light and improving the light utilization efficiency.

[0345] The first mirror 61X and the second mirror 61Y can be any reflective components; there are no particular limitations. For example, the width of the first mirror 61X and the second mirror 61Y can be 1 cm.

[0346] like Figure 10C and Figure 10DAs shown, the liquid crystal display device 1 may also include: a third mirror 62X disposed on the observation surface side of the first light source 31X; a fourth mirror 62Y disposed on the observation surface side of the second light source 31Y; a fifth mirror 63X disposed on the back side of the first back-side light source 32X; and a sixth mirror 63Y disposed on the back side of the second back-side light source 32Y. With this configuration, light from the first light source 31X, the second light source 31Y, the first back-side light source 32X, and the second back-side light source 32Y can be easily concentrated towards the center of the first liquid crystal panel 11.

[0347] The third mirror 62X, the fourth mirror 62Y, the fifth mirror 63X, and the sixth mirror 63Y can all be components with reflective functions; there are no special restrictions.

[0348] like Figure 10C and Figure 10D As shown, the liquid crystal display device 1 may also include: a first anisotropic light-reflecting film 70X, which is disposed between the third mirror 62X and the fifth mirror 63X to receive light irradiated from the first light source 31X and the first back-side light source 32X; and a second anisotropic light-reflecting film 70Y, which is disposed between the fourth mirror 62Y and the sixth mirror 63Y to receive light irradiated from the second light source 31Y and the second back-side light source 32Y. By configuring it in this way, when at least one of the first light source 31X, the second light source 31Y, the first back-side light source 32X, and the second back-side light source 32Y includes an LED, it is not easy to see the LED bright spot from the viewing surface side.

[0349] Examples of brightness enhancement films include the first anisotropic light-reflecting film 70X and the second anisotropic light-reflecting film 70Y. Examples of brightness enhancement films include the aforementioned brightness enhancement films.

[0350] The present invention will be described in more detail below with examples and comparative examples, but the present invention is not limited to these examples.

[0351] (Example 1-1)

[0352] As an example of the liquid crystal display device in Embodiment 1-1, a liquid crystal display device was manufactured. Figure 1 The liquid crystal display device of Embodiment 1 shown above.

[0353] First, the first liquid crystal panel 11 of the liquid crystal display device of Embodiment 1-1 will be described. Preparation: A first substrate 100, having pixel electrodes 120 made of ITO; and a second substrate 200, having a common electrode 220 made of ITO. An alignment film material comprising a photoisomerizing polymer is coated on the side of the pixel electrode 120 opposite to the first support substrate 110 and the side of the common electrode 220 opposite to the second support substrate 210, respectively, and a photoalignment process is performed to form a first alignment film 410 and a second alignment film 420. The first alignment film 410 and the second alignment film 420 are photoaligned in such a way that they are anti-parallel to each other.

[0354] Next, the first substrate 100 and the second substrate 200 are arranged opposite each other with the first alignment film 410 and the second alignment film 420 inside each other. A composition (polymer-dispersed liquid crystal material) containing 90.6 wt% of a host liquid crystal (liquid crystal component 320) as a positive liquid crystal, 8.96 wt% of a photopolymerizable liquid crystal compound (monomer), and 0.448 wt% of a polymerization initiator is injected between the first substrate 100 and the second substrate 200. The liquid crystal component 320 uses a liquid crystal compound with Δn = 0.18, Δε = +20, and rotational viscosity γ1 = 206 mPa·s. As the photopolymerizable liquid crystal compound, a monomer having mesocrystalline groups, photoreactive groups, and acrylate groups is used. As the polymerization initiator, OXE03 (manufactured by BASF) is used.

[0355] The liquid crystal irradiation intensity of this polymer dispersion material is 50 mW / cm. 2 The light irradiation is 2 J / cm². 2 The monomers are polymerized by irradiation with ultraviolet (UV) light (main wavelength 365nm) for 40 seconds, forming a polymer-dispersed liquid crystal 300 between the first substrate 100 and the second substrate 200, thus creating a first liquid crystal panel 11 with a unit thickness of 3μm. No black matrix layer or color filter layer is disposed on the first liquid crystal panel 11.

[0356] The second liquid crystal panel 12 of the liquid crystal display device 1 in Embodiment 1-1 uses a conventional VA mode liquid crystal panel with an orthogonal NIKG polarizer. Furthermore, similar to the prior art, a backlight 50 is disposed on the back side of the second liquid crystal panel 12, and the backlight 50 includes a light guide plate and an LED light source disposed on the end face of the light guide plate.

[0357] The first light source 31X and the second light source 31Y are rod-shaped light sources in which red LED 31R, green LED 31G, and blue LED 31B are arranged in a row, with multiple LEDs of each color. This enables color display by driving the first light source 31X and the second light source 31Y in an FSC manner.

[0358] In Example 1-1, the following settings are made: Figure 1 The lengths and angles of the parts shown.

[0359] h11 = h12 = 8cm

[0360] a = 20cm

[0361] b = 10cm

[0362] θ11=θ12=68°

[0363] The first liquid crystal panel 11 of the liquid crystal display device of Embodiment 1-1 described above is a reverse-type (reverse mode) liquid crystal panel that is transparent when no voltage is applied and diffuses when a voltage is applied. In addition, in Embodiment 1-1, 1≤8≤{20 / tan68°}≈8.08, satisfying the above (Equation 1-1) and (Equation 1-2).

[0364] (Examples 1-2)

[0365] Figure 14 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-2. Figure 15A This is a graph showing the angle dependence of the transmittance of the light-shielding grating provided in the liquid crystal display devices of Embodiments 1-2. Figure 15B yes Figure 15A The diagram shown is an enlarged view of the area enclosed by quadrilaterals. Figure 15C This is a schematic diagram illustrating a method for measuring the angle dependence of the transmittance of the light-shielding grating in the liquid crystal display device of Examples 1-2.

[0366] In addition to having on the viewing surface side of the first liquid crystal panel 11 Figure 15A and Figure 15B The light-shielding grid sheet manufactured by Shin-Etsu Polymer Co., Ltd., which shows the angle dependence of transmittance, was fabricated in the same manner as in Example 1-1, except that it is the light-shielding grid 13. Figure 14 The liquid crystal display device shown in Embodiments 1-2. The light-shielding layers 1311 of the light-shielding grid have a spacing p = 0.100 mm, a viewing angle of 48°, a maximum light transmittance angle of 0°, and a pair of transparent films 132 are each composed of PC films with a thickness of 0.2 mm. The thickness of the light-shielding grid is 0.79 mm.

[0367] Furthermore, in this specification, the angle dependence of the transmittance of the light-shielding grid (such as the light-shielding grid sheet described above) is expressed as follows: Figure 15C The method shown is obtained using the LCD5200 panel module evaluation device (manufactured by Otsuka Electronics Co., Ltd.). Specifically, the LCD5200 panel module evaluation device is used, such as... Figure 15C As shown, the luminance at various angles θ with and without a light-shielding grid was measured. The transmittance at each angle θ was calculated by dividing the luminance with the light-shielding grid by the luminance at θ = 0° without the light-shielding grid. A halogen lamp was used as the light source for the luminance measurements. The measurement wavelength was set to approximately 550 nm, and the light-receiving angle was set to approximately 2°. The light-shielding grid used in Examples 1-2 exhibits a transmittance of less than 1% at θ = 23.5°, demonstrating strong light-shielding performance.

[0368] (Examples 1-3)

[0369] Figure 16 This is a cross-sectional schematic diagram of the liquid crystal display device in Examples 1-3. Figure 17 This is a schematic diagram illustrating a method for measuring the angle dependence of the transmittance of an optical film. Except that an anisotropic light diffusion film 14 is disposed on the back side of the first support substrate 110 in the first liquid crystal panel 11, it is fabricated in the same manner as in Embodiment 1-1. Figure 16 The liquid crystal display device 1 shown in Embodiments 1-3.

[0370] In Examples 1-3, an anisotropic light diffusion film 1-a, exhibiting the optical properties shown in Table 1 below, was used as the anisotropic light diffusion film 14. Table 1 below shows the angle dependence of the transmittance of the anisotropic light diffusion film 1-a.

[0371] Furthermore, in this specification, the angle dependence of the transmittance of optical films such as anisotropic light diffusion films and anisotropic light reflection films is described through... Figure 17 The method shown is obtained using the LCD5200 panel module evaluation device (manufactured by Otsuka Electronics Co., Ltd.). Specifically, the LCD5200 panel module evaluation device is used, such as... Figure 17 As shown, the luminance at various angles θi (=θd) with the optical film was measured. The transmittance at each angle θi (=θd) was calculated by dividing the luminance at each angle θi (=θd) by the luminance at angle θi=θd=0°. That is, the transmittance at 0° was set to 100%, and the transmittance at each angle was calculated. A halogen lamp was used as the light source for the luminance measurement. The measurement wavelength was set to approximately 550nm, and the light-receiving angle was set to approximately 2°. Figure 17 In the figure, anisotropic light diffusion film and anisotropic light reflection film are shown as optical films.

[0372] Table 1

[0373] angle transmittance 0° 100％ ±15° 95％ ±30° 31～36％ ±40° 3.1～3.3％ ±45° 3.1～3.5％ ±50° 2.9～3.3％ ±60° 1.3～1.4％

[0374] (Examples 1-4)

[0375] Figure 18 This is a cross-sectional schematic diagram of the liquid crystal display device of Embodiments 1-4. Except that an anisotropic light-reflecting film 15 is disposed on the observation surface side of the fourth support substrate 910 in the second liquid crystal panel 12, and a first mirror 61X and a second mirror 61Y are disposed at both ends of the anisotropic light-reflecting film 15, so that light from the first light source 31X and the second light source 31Y is emitted towards the back side, and θ11=θ12=75° is set, the device is manufactured in the same manner as in Embodiments 1-1. Figure 18 The liquid crystal display device 1 shown in Embodiments 1-4.

[0376] In Examples 1-4, an anisotropic light-reflecting film 15 was used, exhibiting the optical properties shown in Table 2 below. Table 2 shows the angle dependence of the transmittance of the anisotropic light-reflecting film.

[0377] Table 2

[0378] angle transmittance 0° 100％ ±15° 98～99％ ±30° 93～94％ ±40° 87～88％ ±45° 82～83％ ±50° 76～77％ ±60° 63～64％

[0379] In Examples 1-4, 1≤4≤{20 / tan75°}≈5.36, satisfying the above (Equation 1-1) and (Equation 1-2).

[0380] (Examples 1-5)

[0381] Figure 19 This is a cross-sectional schematic diagram of the liquid crystal display device of Embodiments 1-5. Except that an anisotropic light diffusion film 14 is disposed on the back side of the first support substrate 110 in the first liquid crystal panel 11, and an anisotropic light reflection film 15 is disposed on the observation surface side of the fourth support substrate 910 in the second liquid crystal panel 12, and a first mirror 61X and a second mirror 61Y are disposed at both ends of the anisotropic light reflection film 15, so that light from the first light source 31X and the second light source 31Y is emitted towards the back side, and is set with h11 = h12 = 4cm, b = 5cm, θ11 = θ12 = 75°, the device is manufactured in the same manner as in Embodiments 1-1. Figure 19 The liquid crystal display device 1 shown in Embodiments 1-5.

[0382] In Examples 1-5, the anisotropic light diffusion film 14 is the same as the above-mentioned anisotropic light diffusion film 1-a, and the anisotropic light reflection film 15 is the same as the anisotropic light reflection film exhibiting the optical properties shown in Table 2 above.

[0383] In Examples 1-5, 1≤4≤{20 / tan75°}≈5.36cm, satisfying the above (Equation 1-1) and (Equation 1-2).

[0384] (Examples 1-6)

[0385] Except for setting h11=h12=8cm, b=10cm, and θ11=θ12=68°, the liquid crystal display device 1 of Examples 1-6 was manufactured in the same manner as Examples 1-5.

[0386] In Examples 1-6, 1≤8≤{20 / tan68°}≈8.08, satisfying the above (Equation 1-1) and (Equation 1-2).

[0387] (Example 2-1)

[0388] Figure 20 This is a cross-sectional schematic diagram of the liquid crystal display device of Embodiment 2-1. A fabricated... Figure 20 The liquid crystal display device 1 of Embodiment 2-1 shown has the same configuration as Embodiment 1-1 except that it includes a first rear-side light source 32X and a second rear-side light source 32Y. θ21 = θ22 = 57° is set.

[0389] In Example 2-1, 1≤8≤{20 / tan68°}≈8.08cm, satisfying the above (Equation 1-1) and (Equation 1-2), and θ11-θ21=θ12-θ22=68°-57°=11°>10°, satisfying the above (Equation 2-1) and (Equation 2-2).

[0390] (Example 2-2)

[0391] Figure 21 This is a cross-sectional schematic diagram of the liquid crystal display device of Embodiment 2-2. Except that a light-shielding grid 13, identical to the one used in Embodiments 1-2, is disposed on the viewing surface side of the first liquid crystal panel 11, it is manufactured in the same manner as in Embodiment 2-1. Figure 21 The liquid crystal display device shown in Embodiment 2-2.

[0392] (Examples 2-3)

[0393] In addition to Figure 10C Except for the anisotropic light diffusion film 14 provided on the back side of the first support substrate 110 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiment 2-3 was manufactured in the same manner as Embodiment 2-1. In Embodiment 2-3, the anisotropic light diffusion film 1-a described above is used as the anisotropic light diffusion film 14.

[0394] (Examples 2-4)

[0395] In addition to Figure 10D Except for the anisotropic light diffusion film 14 provided on the viewing surface side of the second support substrate 210 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiment 2-4 was manufactured in the same manner as Embodiment 2-1. In Embodiment 2-4, the anisotropic light diffusion film 1-a described above is used as the anisotropic light diffusion film 14.

[0396] (Examples 2-5)

[0397] In addition to Figure 10C In addition to the anisotropic light diffusion film 14 being provided on the back side of the first support substrate 110 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiments 2-5 was fabricated in the same manner as Embodiments 2-1. In Embodiments 2-5, anisotropic light diffusion film 1-b having the optical properties shown in Table 3 below was used as the anisotropic light diffusion film 14. Table 3 below shows the angle dependence of the transmittance of the anisotropic light diffusion film 1-b.

[0398] Table 3

[0399] angle transmittance 0° 100％ ±15° 97～98％ ±30° 72～89％ ±40° 8～13％ ±45° 3.1～3.6％ ±50° 3.4％ ±60° 1.7～2.2％

[0400] (Examples 2-6)

[0401] In addition to Figure 10D Except for the anisotropic light diffusion film 14 provided on the viewing surface side of the second support substrate 210 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiments 2-6 was manufactured in the same manner as Embodiments 2-1. In Embodiments 2-6, the anisotropic light diffusion film 1-b described above is used as the anisotropic light diffusion film 14.

[0402] (Examples 2-7)

[0403] In addition to Figure 10C Except for the anisotropic light diffusion film 14 provided on the back side of the first support substrate 110 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiments 2-7 was fabricated in the same manner as Embodiments 2-1. In Embodiments 2-7, anisotropic light diffusion film 1-c with the optical properties shown in Table 4 below was used as the anisotropic light diffusion film 14. Table 4 below shows the angle dependence of the transmittance of the anisotropic light diffusion film 1-c.

[0404] Table 4

[0405] angle transmittance -60° 1.7％ -50° 3.0％ -45° 4.2％ -40° 3.7％ -30° 21％ -15° 92％ 0° 100％ +15° 100％ +30° 98％ +40° 95％ +45° 93％ +50° 90％ +60° 81％

[0406] (Examples 2-8)

[0407] In addition to Figure 10DExcept for the anisotropic light diffusion film 14 provided on the viewing surface side of the second support substrate 210 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiments 2-8 was fabricated in the same manner as Embodiments 2-1. In Embodiments 2-8, the anisotropic light diffusion film 1-c described above is used as the anisotropic light diffusion film 14.

[0408] (Examples 2-9)

[0409] In addition to Figure 10C Except for the anisotropic light diffusion film 14 provided on the back side of the first support substrate 110 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiments 2-9 was fabricated in the same manner as Embodiments 2-1. In Embodiments 2-9, anisotropic light diffusion films 1-d having the optical properties shown in Table 5 below were used as the anisotropic light diffusion film 14. Table 5 below shows the angle dependence of the transmittance of the anisotropic light diffusion film 1-d.

[0410] Table 5

[0411] angle transmittance -60° 2.3％ -50° 3.5％ -45° 3.7％ -40° 13％ -30° 79％ -15° 98％ 0° 100％ +15° 100％ +30° 98％ +40° 95％ +45° 93％ +50° 90％ +60° 81％

[0412] (Example 2-10)

[0413] In addition to Figure 10D Except for the anisotropic light diffusion film 14 provided on the viewing surface side of the second support substrate 210 in the first liquid crystal panel 11 shown, the liquid crystal display device 1 of Embodiment 2-10 was manufactured in the same manner as Embodiment 2-1. In Embodiment 2-10, the anisotropic light diffusion film 1-d described above is used as the anisotropic light diffusion film 14.

[0414] (Example 2-11)

[0415] Except that an anisotropic light-reflecting film 15 is disposed on the viewing surface side of the fourth support substrate 910 in the second liquid crystal panel 12, the liquid crystal display device 1 of Embodiment 2-11 is manufactured in the same manner as Embodiment 2-1. In Embodiment 2-11, an anisotropic light-reflecting film exhibiting the optical characteristics shown in Table 2 above is used as the anisotropic light-reflecting film 15.

[0416] (Example 2-12)

[0417] Except that an anisotropic light diffusion film 14 is disposed on the back side of the first support substrate 110 in the first liquid crystal panel 11, and an anisotropic light reflection film 15 is disposed on the observation surface side of the fourth support substrate 910 in the second liquid crystal panel 12, the liquid crystal display device 1 of Embodiment 2-12 was manufactured in the same manner as Embodiment 2-1.

[0418] In Examples 2-12, the above-mentioned anisotropic light diffusion film 1-a is used as the anisotropic light diffusion film 14, and the anisotropic light reflection film 15 is used as the anisotropic light reflection film exhibiting the optical properties shown in Table 2 below.

[0419] (Comparative Example 1)

[0420] Figure 22 This is a cross-sectional schematic diagram of the liquid crystal display device of Comparative Example 1. A backlight source 50R was disposed on the back side of a first liquid crystal panel 11 manufactured in the same manner as in Example 1-1 via an adhesive member 80 such as an OCA, and a liquid crystal display device 1RF of Comparative Example 1 was manufactured. The backlight source 50R has an LED light source 51R on the end face of a light guide plate 52R.

[0421] (Evaluation of Examples and Comparative Examples)

[0422] Regarding the above embodiments and comparative examples, the transmittance in the transparent state, the front brightness of the central portion of the panel in the scattering state, the front contrast of the central portion of the panel, and the visibility of the LED highlights when viewed at an angle were evaluated. The results are shown in Table 6 below.

[0423] Furthermore, the evaluations are conducted as follows.

[0424] <Transmittance in transparent state>

[0425] Using a luminance meter (SR-UL1) manufactured by Topcon, the luminance was measured when the 19-inch first liquid crystal panels of each embodiment and comparative example were arranged on a conventional backlight (light source for a liquid crystal display device) in a state without applied voltage, and when nothing was arranged on the aforementioned backlight. The transmittance in the transparent state was obtained by dividing the luminance when the first liquid crystal panel was arranged in a state without applied voltage by the luminance when nothing was arranged on the aforementioned backlight. In the luminance measurement, a halogen lamp was used as the light source, the light reception angle was set to 2°, and the measurement wavelength was set to approximately 550 nm.

[0426] <Brightness and contrast of the center of the panel under diffused light conditions>

[0427] A 19-inch first liquid crystal panel of each embodiment and comparative example was placed on a conventional backlight (light source for a liquid crystal display device). The distance between the first liquid crystal panel and the luminance meter manufactured by Topcon was set to approximately 50 cm. The luminance in a diffused state (white luminance) and the luminance in a transparent state were measured in a dark room. The luminance in the diffused state was set as the front luminance of the central part of the panel in the diffused state. In addition, the front contrast ratio of the central part of the panel was obtained by dividing the luminance in the diffused state by the luminance in the transparent state. In the luminance measurement, a halogen lamp was used as the light source, the light reception angle was set to 2°, and the measurement wavelength was set to approximately 550 nm.

[0428] <Visibility of LED highlights when viewed at an angle>

[0429] Subjective evaluation is conducted by visually identifying the bright lines of the red LED31R, green LED31G, and blue LED31B.

[0430] Table 6

[0431]

[0432] In Table 6 above, subjective evaluation is defined as follows.

[0433] ◎: Excellent

[0434] 〇: Good

[0435] △: Standard

[0436] ×: difference

[0437] In Table 6 above, it is important that the observer cannot see the LED light when viewing at an angle.

[0438] Furthermore, the NTSC ratio was measured for the liquid crystal display devices of Examples 2-3, 2-7 to 2-10, and Comparative Example 1. The NTSC ratio was 5.7% in Examples 2-3, 2.8% in Examples 2-7, 2.8% in Examples 2-8, 2.5% in Examples 2-9, 2.6% in Examples 2-10, and 20.5% in Comparative Example 1. The NTSC ratio was measured as follows: For the first liquid crystal panel of each example and comparative example, the chromaticity (x, y) of each RGB color gamut was measured using a luminance meter (SR-UL1) manufactured by Topcon Corporation, the covered color gamut (area) was calculated, and the ratio of this area to the NTSC (color gamut standard) area was obtained.

[0439] In the liquid crystal display devices of Examples 1-1 to 1-6 and 2-1 to 2-12, since the first liquid crystal panel has polymer-dispersed liquid crystal, image display can be performed without using a polarizer, and the decrease in transmittance in the transparent state can be suppressed. Furthermore, in Examples 1-1 to 1-6 and 2-1 to 2-12, since light is irradiated onto the main surface 11P of the back side of the first liquid crystal panel 11 from an inclined direction, the front brightness and front contrast of the central portion of the panel in the scattered state can be improved. On the other hand, in Comparative Example 1, since the light from the LED light source 51R is incident from the end face of the light guide plate 52R, the front brightness and front contrast of the central portion of the panel in the scattered state cannot be improved.

[0440] Furthermore, since the liquid crystal display devices of Examples 1-1 to 1-6 satisfy (Equation 1-1) and (Equation 1-2), the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state and enable a brighter display.

[0441] Furthermore, since the liquid crystal display devices of Examples 2-1 to 2-2 satisfy (Equation 1-1) and (Equation 1-2), as well as (Equation 2-1) and (Equation 2-2), the front scattering component in the scattering state becomes stronger, which can further suppress the decrease in brightness of the central part of the panel in the scattering state and enable a brighter display.

[0442] For example, if h11 = h12 = 2cm, although equations (1-1) and (1-2) are not satisfied, it is conceivable that the front brightness of the central part of the panel in the scattering state would be less than 100cd under such circumstances.

[0443] The brightness of the front panel of the liquid crystal display device 1 in the RF scattering state of Comparative Example 1 is 60 cd / m². 2 The front contrast ratio of the central part of the panel is 1.4, which is poor display quality from the front and is at a level that makes the observer feel uncomfortable.

[0444] Figure 23 This is a schematic diagram illustrating the evaluation of LED highlights. In a liquid crystal display device equipped with a light-shielding grille 13, such as in Embodiments 1-2 or 2-2, as... Figure 23 As shown, no LED bright spots are observed when viewed from observation positions 2 and 3 from an inclined direction.

Claims

1. A liquid crystal display device, characterized in that, Features are arranged in sequence from the observation side to the rear side: First LCD panel, light source, and second LCD panel, The aforementioned first liquid crystal panel comprises a polymer-dispersed liquid crystal including a polymer network and liquid crystal components. The aforementioned light source illuminates the main surface of the back side of the aforementioned first liquid crystal panel from an oblique direction. A rear-side light source is also provided between the aforementioned light source and the aforementioned second liquid crystal panel. The aforementioned rear-side light source illuminates the main surface of the rear side of the aforementioned first liquid crystal panel from an oblique direction.

2. The liquid crystal display device according to claim 1, characterized in that, The aforementioned first liquid crystal panel displays images in field-sequential color mode. The aforementioned light source comprises multiple light-emitting elements that emit light of different colors.

3. The liquid crystal display device according to claim 1, characterized in that, The aforementioned first liquid crystal panel also features thin-film transistors.

4. The liquid crystal display device according to claim 1, characterized in that, When the length of the long side of the first liquid crystal panel is set to 2a [cm], The distance between the first liquid crystal panel and the second liquid crystal panel is less than a [cm].

5. The liquid crystal display device according to claim 1, characterized in that, When the length of the long side of the first liquid crystal panel is set to 2a [cm], the distance between the first liquid crystal panel and the light source is set to h11 [cm], and the incident angle of the light from the light source on the main surface of the back side of the first liquid crystal panel is set to θ11 [°], the following (Equation 1-1) is satisfied: 1≤h11≤{a / (tanθ11)}…(Formula 1-1).

6. The liquid crystal display device according to claim 1, characterized in that, The aforementioned light source is a first light source, and is disposed corresponding to one of the pair of opposing end portions of the aforementioned first liquid crystal panel. A second light source is provided between the first liquid crystal panel and the second liquid crystal panel, and the second light source is disposed corresponding to the other end edge portion of the pair of end edge portions. The second light source illuminates the main surface of the back side of the first liquid crystal panel from an oblique direction. The angle of incidence of light from the first light source onto the main surface of the back side of the first liquid crystal panel is the same as the angle of incidence of light from the second light source onto the main surface of the back side of the first liquid crystal panel.

7. The liquid crystal display device according to claim 1, characterized in that, When the length of the long side of the first liquid crystal panel is set to 2a [cm], the distance between the first liquid crystal panel and the light source is set to h11 [cm], the incident angle of the light from the light source on the main surface of the back side of the first liquid crystal panel is set to θ11 [°], and the incident angle of the light from the back side light source on the main surface of the back side of the first liquid crystal panel is set to θ21 [°], the following (Equation 1-1) and (Equation 2-1) are satisfied: 1≤h11≤{a / (tanθ11)}…(Formula 1-1) θ11-θ21>10°…(Formula 2-1).

8. The liquid crystal display device according to claim 1, characterized in that, The aforementioned rear-side light source is a first rear-side light source, and is disposed corresponding to one of the pair of opposing end edges of the aforementioned first liquid crystal panel. A second rear-side light source is also provided between the aforementioned light source and the aforementioned second liquid crystal panel, and the aforementioned second rear-side light source is disposed corresponding to the other end edge portion of the aforementioned pair of end edge portions. The aforementioned second rear-side light source illuminates the main surface of the rear side of the aforementioned first liquid crystal panel from an oblique direction. The angle of incidence of light from the first rear-side light source onto the main surface of the rear side of the first liquid crystal panel is the same as the angle of incidence of light from the second rear-side light source onto the main surface of the rear side of the first liquid crystal panel.

9. The liquid crystal display device according to any one of claims 1 to 8, characterized in that, The first liquid crystal panel further comprises: a first support substrate disposed on the back side of the polymer-dispersed liquid crystal; and a second support substrate disposed on the viewing side of the polymer-dispersed liquid crystal.

10. The liquid crystal display device according to claim 9, characterized in that, The first liquid crystal panel further comprises an alignment film, which is disposed between at least one of the first support substrate and the polymer-dispersed liquid crystal, and between the second support substrate and the polymer-dispersed liquid crystal. The aforementioned alignment film is a horizontal alignment film in which the liquid crystal component is aligned parallel to the surface of the alignment film.

11. The liquid crystal display device according to claim 10, characterized in that, The aforementioned liquid crystal components exhibit positive dielectric anisotropy.

12. The liquid crystal display device according to claim 9, characterized in that, The first liquid crystal panel further comprises a transparent resin plate disposed on the back side of the first support substrate.

13. The liquid crystal display device according to claim 9, characterized in that, The first liquid crystal panel also has an anisotropic light diffusion film on at least one of the back side of the first support substrate and the viewing side of the second support substrate. The anisotropic light diffusion film has the function of allowing light to pass through when viewed from the front and scattering light when viewed at an angle.

14. The liquid crystal display device according to any one of claims 1 to 8, 10 to 13, characterized in that, The aforementioned second liquid crystal panel comprises, in sequence from the back side to the viewing side: a third support substrate; a liquid crystal layer; a fourth support substrate; and an anisotropic light-reflecting film, which has the function of allowing light to pass through when viewed from the front and reflecting light when viewed at an angle.

Images