Liquid crystal panel and method for manufacturing liquid crystal panel

Abstract

To drop a driving voltage.SOLUTION: A liquid crystal panel 10 includes substrates 11 and 12 each having main surfaces 11S and 12S with anisotropy in surface energy; a liquid crystal layer 13 composed of a liquid crystal material; and phase separation layers 19 and 20 disposed between the main surfaces 11S and 12S and the liquid crystal layer 13 and are phase-separated from the liquid crystal layer 13.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a liquid crystal panel with a reduced driving voltage and a method for manufacturing the liquid crystal panel. [Background technology]

[0002] A liquid crystal panel disclosed in Patent Document 1 below has been known in the past. The liquid crystal panel described in Patent Document 1 has a pair of substrates, a pair of electrodes formed on each of the pair of substrates, and a liquid crystal layer sandwiched between the pair of electrodes. At least one of the pair of electrodes is mainly composed of an inorganic conductive layer, and has an uneven surface that aligns liquid crystal molecules in the liquid crystal layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-264504 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid crystal panel described in Patent Document 1, multiple protrusions are arranged at intervals on the surface of the inorganic conductive layer, which tends to cause excessive anchoring of the liquid crystal molecules, resulting in a problem of high drive voltage.

[0005] The technology described in this specification was developed based on the above circumstances, and aims to reduce the driving voltage. [Means for solving the problem]

[0006] (1) A liquid crystal panel according to the technology described in this specification includes a substrate having a main surface with anisotropic surface energy, a liquid crystal layer made of a liquid crystal material, and a phase separation layer disposed between the main surface and the liquid crystal layer and phase-separated from the liquid crystal layer.

[0007] (2) In addition to the above (1), the liquid crystal panel may further include an alignment film having the main surface, the alignment film being made of a polymer material and having a plurality of protrusions arranged at intervals within the main surface and protruding from the main surface toward the liquid crystal layer, and the phase separation layer may have a thickness extending from the main surface to a height lower than the protruding tips of the protrusions.

[0008] (3) In addition to the above (2), the liquid crystal panel may also be configured such that the plurality of protrusions stand up along an axis tilted relative to the main surface, and some of the plurality of protrusions may be in contact with each other.

[0009] (4) In addition to the above (2) or (3), the liquid crystal panel may be configured such that the height of the plurality of protrusions from the main surface is greater than the distance between adjacent protrusions.

[0010] (5) In addition to any one of (2) to (4), the liquid crystal panel may be configured such that the alignment film contains polydimethylsiloxane.

[0011] (6) In addition to any one of (1) to (5), the liquid crystal panel may further include partition walls extending from the main surface toward the liquid crystal layer and dividing the main surface into a plurality of partition regions, and the phase separation layer may be composed of a plurality of divided phase separation layers arranged in the plurality of partition regions.

[0012] (7) In addition to the above (6), the liquid crystal panel may have a plurality of alignment control protrusions within the partition wall, and the alignment control protrusions may have an asymmetric cross section.

[0013] (8) In addition to the above (6) or (7), the partition walls of the liquid crystal panel may have an alignment treatment applied to their leading edge surfaces rising from the main surface.

[0014] (9) In addition to the above (6) or (7), the liquid crystal panel may be configured such that the partition walls have asymmetric planar shapes.

[0015] (10) In addition to any one of (1) to (9), the liquid crystal panel may be configured such that the phase separation layer contains polydimethylsiloxane.

[0016] (11) In addition to any one of (1) to (10), the liquid crystal panel may be configured such that the liquid crystal layer is a dichroic liquid crystal layer containing a dichroic dye.

[0017] (12) A method for manufacturing a liquid crystal panel according to the technology described in this specification includes imparting anisotropy to the surface energy of a main surface of a substrate, providing a phase separation layer on the main surface, and providing a liquid crystal layer sandwiching the phase separation layer between the main surface and the substrate.

[0018] (13) In addition to the above (12), the method for manufacturing the liquid crystal panel may further include providing an alignment film having the main surface and made of a polymer material, and when providing the alignment film, providing a plurality of protrusions arranged at intervals within the main surface and rising from the main surface, and then performing a rubbing treatment on the plurality of protrusions, thereby causing the plurality of protrusions to rise along an axis tilted with respect to the main surface, and causing the plurality of protrusions to include protrusions that are in contact with each other.

[0019] (14) In addition to the above (13), the method for manufacturing the liquid crystal panel may further include the steps of: when providing the alignment film, applying a material for the alignment film to a textured surface of a stamp substrate having a textured surface, bonding the stamp substrate to the substrate to bring the material for the alignment film into contact with the substrate, hardening the material for the alignment film, and then peeling the stamp substrate from the substrate. [Effects of the Invention]

[0020] The techniques described herein can reduce the driving voltage. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic cross-sectional view of a liquid crystal panel according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view of a liquid crystal panel according to a first embodiment, showing a liquid crystal layer, alignment films, and phase separation layers. [Figure 3] FIG. 1 is a diagram showing the chemical formula of trimethylolpropane triacrylate that can be contained in the acrylic monomer mixture that constitutes each alignment film according to embodiment 1. [Figure 4] FIG. 1 is a diagram showing the chemical formula of "Silaplane (registered trademark) FM-7711" that can be included in the acrylic monomer mixture that constitutes each alignment film according to embodiment 1. [Figure 5] FIG. 1 is a diagram showing the chemical formula of “Omnirad 651” that can be included in the acrylic monomer mixture that constitutes each alignment film according to embodiment 1. [Figure 6] FIG. 1 shows the chemical formula of the "TSF451" series that can be contained in each phase separation layer according to embodiment 1. [Figure 7] Graph showing experimental results of Comparative Experiment 1 according to Embodiment 1 [Figure 8] Graph showing experimental results of Comparative Example 2 of Comparative Experiment 2 according to Embodiment 1 [Figure 9] Graph showing experimental results of Example 2 of Comparative Experiment 2 according to Embodiment 1 [Figure 10] Graph showing experimental results of Example 3 of Comparative Experiment 2 according to Embodiment 1 [Figure 11] Graph showing experimental results of Comparative Experiment 3 according to Embodiment 1 [Figure 12] Graph showing the relationship between anchoring energy and delay time of liquid crystal according to embodiment 1. [Figure 13] 1 is a graph showing the relationship between the pretilt angle of the liquid crystal and the content of PDMS in the alignment film according to Embodiment 1. [Figure 14]Graph showing the relationship between temperature and concentration of liquid crystal E7 according to embodiment 1. [Figure 15] 1 is a cross-sectional view showing a state before a material for a first alignment film is applied to the uneven surface of a stamp substrate in a first alignment film forming step included in a manufacturing method of a liquid crystal panel according to Embodiment 1. [Figure 16] 1 is a cross-sectional view illustrating a state in which ultraviolet light is irradiated onto both substrates enclosed in a vacuum packing member in a first alignment film forming step included in a manufacturing method of a liquid crystal panel according to Embodiment 1. [Figure 17] 1 is a cross-sectional view illustrating a state in which a first alignment film is provided on a first substrate in a first alignment film forming step included in a method for manufacturing a liquid crystal panel according to Embodiment 1. [Figure 18] 1 is a cross-sectional view showing a state before a rubbing treatment is performed on a first alignment film in a first alignment film forming step included in a method for manufacturing a liquid crystal panel according to Embodiment 1. [Figure 19] FIG. 10 is a cross-sectional view showing a state in which a plurality of first protrusions are tilted by a rubbing treatment in a first alignment film forming step included in the method for manufacturing a liquid crystal panel according to Embodiment 1. [Figure 20] 1 is a cross-sectional view showing a state in which a first phase separation layer is provided in a first phase separation layer forming step included in a method for manufacturing a liquid crystal panel according to Embodiment 1. [Figure 21] FIG. 10 is a plan view showing partition walls and partition areas of a first substrate provided in a liquid crystal panel according to a second embodiment. [Figure 22] 10 is a cross-sectional view of a first substrate according to a second embodiment. [Figure 23] FIG. 10 is a plan view showing partition walls and partition areas of a first substrate provided in a liquid crystal panel according to a third embodiment. [Figure 24] FIG. 10 is a plan view showing partition walls and partition areas of a first substrate provided in a liquid crystal panel according to a fourth embodiment. [Figure 25] FIG. 10 is a plan view showing alignment control convex portions arranged in a range overlapping with pixels on a first substrate provided in a liquid crystal panel according to a fifth embodiment. [Figure 26] FIG. 13 is a plan view showing partition walls and partition areas of a first substrate provided in a liquid crystal panel according to a sixth embodiment. [Figure 27] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (1). [Figure 28] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (2). [Figure 29] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (3). [Figure 30] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (4). [Figure 31] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (5). [Figure 32] FIG. 10 is a plan view showing an alignment control protrusion according to another embodiment (6). DETAILED DESCRIPTION OF THE INVENTION

[0022] <Embodiment 1> Embodiment 1 will be described with reference to Figs. 1 to 20. In this embodiment, a liquid crystal panel 10 used in a liquid crystal display device will be illustrated. Note that X-axis, Y-axis, and Z-axis are shown in a portion of each drawing, and each axis direction is depicted as being in the direction shown in each drawing. Also, the upper side of Figs. 1 and 2 is the front side, and the lower side of the drawings is the back side.

[0023] As shown in FIG. 1, the liquid crystal panel 10 is formed by bonding a pair of substrates 11 and 12 together. The front side (front surface) of the pair of substrates 11 and 12 is the first substrate (substrate) 11, and the back side (rear surface) is the second substrate (substrate) 12. Both the first substrate 11 and the second substrate 12 are formed by laminating various films on the inner surface of a glass substrate 10GS. The first substrate 11 and the second substrate 12 have main surfaces 11S and 12S extending along the X-axis and Y-axis directions, respectively. A liquid crystal layer 13 containing a liquid crystal material (liquid crystal molecules), which is a substance whose optical properties change when an electric field is applied, is disposed between the pair of substrates 11 and 12. A seal portion 14 is disposed between the outer peripheral edges of the pair of substrates 11 and 12 to seal the liquid crystal layer 13. The seal portion 14 is formed in a rectangular frame shape (endless ring) to surround the liquid crystal layer 13. Incidentally, polarizing plates (not shown) may be attached to the outer surfaces of both substrates 11 and 12, respectively.

[0024] In this embodiment, the liquid crystal layer 13 contains a dichroic dye in addition to a liquid crystal material. That is, the liquid crystal layer 13 is a dichroic liquid crystal layer (GH (guest-host) liquid crystal layer). The dichroic dye is a rod-shaped compound, similar to the liquid crystal molecules that make up the liquid crystal material, and has the property of varying light absorption depending on its axial direction. Specifically, for example, when the dichroic dye is oriented such that its axial direction is approximately aligned with the normal direction to the main surface of the glass substrate 10GS, it transmits almost no light without absorbing it, but when its axial direction is approximately perpendicular (intersecting) the normal direction to the main surface of the glass substrate 10GS, it absorbs most of the light. The dichroic dye is oriented along the liquid crystal molecules and follows the movement of the liquid crystal molecules. The pair of substrates 11 and 12 are each provided with electrodes (not shown). The orientation of the liquid crystal molecules and the dichroic dye changes depending on the electric field applied to the liquid crystal layer 13 by these electrodes, thereby controlling the amount of light transmitted through the liquid crystal panel 10. The electrodes provided on each of the pair of substrates 11 and 12 are made of a transparent electrode material such as ITO (Indium Tin Oxide).

[0025] As shown in FIG. 2, a first alignment film (alignment film) 15 is provided on the first substrate 11. Similarly, a second alignment film (alignment film) 16 is provided on the second substrate 12. The surface of the first alignment film 15 facing the liquid crystal layer 13 constitutes a first main surface 11S of the first substrate 11. The surface of the second alignment film 16 facing the liquid crystal layer 13 constitutes a second main surface 12S of the second substrate 12. Each of the alignment films 15, 16 can align the liquid crystal molecules contained in the liquid crystal layer 13 while providing a pretilt angle to the molecules. The base of each of the alignment films 15, 16 on each of the substrates 11, 12 may be the electrode described above, or may be an insulating film or the like.

[0026] Each alignment film 15, 16 is made of a so-called "horizontal alignment" type material that aligns the liquid crystal molecules so that their long axes are parallel to the surface of each alignment film 15, 16. Each alignment film 15, 16 is made of a polymer material, such as an acrylic monomer mixture. The acrylic monomer mixture constituting each alignment film 15, 16 includes a polyfunctional acrylate and a monofunctional acrylate, as well as a polymerization initiator. Specifically, the acrylic monomer mixture constituting each alignment film 15, 16 may include a polyfunctional acrylate such as trimethylolpropane triacrylate or polydimethylsiloxane (PDMS: dimethylpolysiloxane). The chemical formula of trimethylolpropane triacrylate is shown in Figure 3. The acrylic monomer mixture constituting each of the alignment films 15 and 16 may contain, as a monofunctional acrylate, methyl acrylate, butyl acrylate, isobornyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, 3-methacryloxypropyltrimethoxysilane, etc. The acrylic monomer mixture constituting each of the alignment films 15 and 16 may contain a photopolymerization initiator as a polymerization initiator, and examples of the photopolymerization initiator that can be used include the "Omnirad" series manufactured by IGM Resins.

[0027] Next, specific compositions of the acrylic monomer mixtures constituting the alignment films 15 and 16 will be illustrated. The acrylic monomer mixtures constituting the alignment films 15 and 16 may include, for example, approximately 5 g of butyl acrylate as a monofunctional acrylate, approximately 5 g of Silaplane (registered trademark) FM-7711 manufactured by JNC Corporation as a polyfunctional acrylate, and approximately 0.2 g of Omnirad 651 manufactured by IGM Resins as a polymerization initiator. Among these, Silaplane (registered trademark) FM-7711 is a type of polydimethylsiloxane. The chemical formula of Silaplane (registered trademark) FM-7711 is shown in FIG. 4. Omnirad 651 is 2,2-dimethoxy-2-phenylacetophenone, which becomes a radical upon irradiation with ultraviolet light and can initiate polymerization. The chemical formula of Omnirad 651 is shown in FIG. 5.

[0028] Alternatively, the acrylic monomer mixture constituting each of the alignment films 15 and 16 may use, for example, about 1.36 g of trimethylolpropane triacrylate as the polyfunctional acrylate, about 5.8 g of isobornyl acrylate as the monofunctional acrylate, about 2.72 g of n-octyl acrylate as the monofunctional acrylate, and about 0.3 g of "Omnirad 651" manufactured by IGM Resins as the polymerization initiator. Alternatively, the acrylic monomer mixture constituting each of the alignment films 15 and 16 may use, for example, about 1.52 g of trimethylolpropane triacrylate as the polyfunctional acrylate, about 8.3 g of 2-ethylhexyl acrylate as the monofunctional acrylate, about 0.747 g of n-octyl acrylate as the monofunctional acrylate, and about 0.18 g of "Omnirad 651" manufactured by IGM Resins as the polymerization initiator. In addition, the acrylic monomer mixture constituting each alignment film 15, 16 may use, for example, about 0.95 g of trimethylolpropane triacrylate as a polyfunctional acrylate, about 8 g of hexyl acrylate as a monofunctional acrylate, about 1.5 g of 3-methacryloxypropyltrimethoxysilane as a monofunctional acrylate, and about 0.095 g of "Omnirad 651" manufactured by IGM RESINS as a polymerization initiator.

[0029] As shown in FIG. 2, the first alignment film 15 is provided with first protrusions (protrusions) 17 that protrude from the first major surface 11S toward the liquid crystal layer 13. Similarly, the second alignment film 16 is provided with second protrusions (protrusions) 18 that protrude from the second major surface 12S toward the liquid crystal layer 13. The protrusions 17, 18 are arranged in groups of two at intervals P1, P2 within each major surface 11S, 12S. The protrusions 17, 18 are dot-like in plan view within each major surface 11S, 12S, and are arranged two-dimensionally within each major surface 11S, 12S. For example, the plurality of protrusions 17, 18 may include protrusions that are arranged at intervals P1, P2 along the X-axis direction and protrusions that are arranged at intervals P1, P2 along the Y-axis direction, or protrusions that are arranged at intervals P1, P2 along other directions parallel to each major surface 11S, 12S. As described above, each of the alignment films 15 and 16 has a plurality of protrusions 17 and 18 arranged at intervals P1 and P2, resulting in anisotropy in surface energy. Each of the plurality of protrusions 17 and 18 rises along axes AX1 and AX2 tilted relative to each of the major surfaces 11S and 12S. Although the liquid crystal molecules contained in the liquid crystal layer 13 are aligned horizontally with their long axes aligned along the surfaces of the protrusions 17 and 18, because the protrusions 17 and 18 rise from the major surfaces 11S and 12S, they are aligned substantially perpendicular to the major surfaces 11S and 12S.

[0030] Specifically, as shown in FIG. 2, the first protrusion 17 rises from the first main surface 11S diagonally upward to the left in FIG. 2 along the first axis AX1. The first protrusion 17 may rise linearly from the first main surface 11S, or may rise curvedly from the first main surface 11S. The multiple first protrusions 17 include multiple first protrusions 17 aligned along a vector component along the first main surface 11S among vector components included in the first axis AX1. Adjacent first protrusions 17 separated by an interval P1 in the vector component along the first main surface 11S that is included in the first axis AX1 are in contact with each other. Specifically, the protruding tip 17A of one first protrusion 17 contacts an intermediate portion between the protruding base end 17B and the protruding tip 17A of the adjacent first protrusion 17 separated by the interval P1.

[0031] As shown in FIG. 2, the second protrusion 18 rises from the second main surface 12S diagonally downward to the right in FIG. 2 along the second axis AX2. The second protrusion 18 may rise linearly from the second main surface 12S or may rise curvedly from the second main surface 12S. The plurality of second protrusions 18 includes a plurality of second protrusions 18 aligned along a vector component along the second main surface 12S among vector components included in the second axis AX2. Adjacent second protrusions 18 separated by a distance P2 in the vector component along the second main surface 12S that is included in the second axis AX2 are in contact (adhesion) with each other. Specifically, for example, the protruding tip 18A of one second protrusion 18 may be in contact with an intermediate portion between the protruding base end 18B and the protruding tip 18A of the adjacent second protrusion 18 separated by the distance P2.

[0032] As shown in FIG. 2, the protrusions 17, 18 are arranged such that the arrangement intervals P1, P2 are in the range of, for example, 100 nm to 200 nm. The reason why the arrangement intervals P1, P2 of the protrusions 17, 18 are in the above-mentioned range is due to the manufacturing method described below. The protrusions 17, 18 have heights H1, H2 rising from the respective main surfaces 11S, 12S in the range of, for example, 100 nm to 200 nm. By making the heights H1, H2 of the protrusions 17, 18 100 nm or more, it is possible to increase the reliability of the contact between adjacent protrusions 17, 18 spaced apart by the intervals P1, P2. By making the heights H1, H2 of the protrusions 17, 18 200 nm or less, the amount of liquid crystal molecules filling (sandwiched) between the contacting protrusions 17, 18 is sufficiently reduced, which makes it less likely to adversely affect the contrast performance of the display. The thicknesses D1 and D2 of the protrusions 17 and 18 are, for example, in the range of 80 nm to 150 nm. By making the thicknesses D1 and D2 of the protrusions 17 and 18 80 nm or more, sufficient mechanical strength is obtained. This makes it less likely that the protrusions 17 and 18 will be mechanically broken due to friction or the like when they are deformed during manufacturing so as to rise along the axes AX1 and AX2 inclined relative to the main surfaces 11S and 12S. By making the thicknesses D1 and D2 of the protrusions 17 and 18 150 nm or less, it is more likely that the protrusions 17 and 18 will not become deformed when they are deformed during manufacturing so as to rise along the axes AX1 and AX2 inclined relative to the main surfaces 11S and 12S. The protrusions 17, 18 have heights H1, H2 (lengths along the axes AX1, AX2) from the main surfaces 11S, 12S that are greater than the intervals P1, P2 between adjacent protrusions 17, 18. This sufficiently increases the reliability with which adjacent protrusions 17, 18 are kept in contact with each other across the intervals P1, P2.

[0033] As shown in FIG. 2, a first phase separation layer (phase separation layer) 19 that phase-separates from the liquid crystal layer 13 is provided between the first main surface 11S of the first substrate 11 and the liquid crystal layer 13. Similarly, a second phase separation layer (phase separation layer) 20 that phase-separates from the liquid crystal layer 13 is provided between the second main surface 12S of the second substrate 12 and the liquid crystal layer 13. Materials that can be used for each of the phase separation layers 19 and 20 include, for example, the "TSF451" series manufactured by Momentive Performance Materials Japan, LLC, and "Silaplane® FM-7711" manufactured by JNC Corporation. The "TSF451" series, like "Silaplane® FM-7711," is a type of polydimethylsiloxane. The chemical formula of the "TSF451" series is as shown in FIG. 6. Thus, the material for each of the phase separation layers 19 and 20 includes polydimethylsiloxane. If the material of each of the phase separation layers 19 and 20 contains polydimethylsiloxane, and the material of each of the alignment films 15 and 16 contains polydimethylsiloxane, each of the phase separation layers 19 and 20 becomes more easily wettable by each of the alignment films 15 and 16 .

[0034] Furthermore, the phase separation layers 19 and 20 are made of a material different from that of the alignment films 15 and 16. Specifically, if the alignment films 15 and 16 contain, for example, "Silaplane (registered trademark) FM-7711," the phase separation layers 19 and 20 can be made of a material from the "TSF451" series. This makes it possible to avoid polymerization of the alignment films 15 and 16 with the phase separation layers 19 and 20 during the manufacturing process.

[0035] In this embodiment, the alignment films 15 and 16 provided on the substrates 11 and 12 have a plurality of protrusions 17 and 18 arranged at intervals P1 and P2, respectively, as shown in Fig. 2. Therefore, anisotropy is imparted to the surface energy of the main surfaces 11S and 12S of the substrates 11 and 12, respectively, and as a result, the liquid crystal molecules contained in the liquid crystal layer 13 are oriented with a predetermined pretilt angle imparted to them. Furthermore, between the main surfaces 11S, 12S of the substrates 11, 12 and the liquid crystal layer 13, the phase separation layers 19, 20, which are phase-separated from the liquid crystal layer 13, are disposed. This weakens the anchoring effect exerted by the phase separation layers 19, 20 on the liquid crystal molecules at the interfaces between the phase separation layers 19, 20 and the liquid crystal layer 13 compared to when the phase separation layers 19, 20 were not present (BUNSEKI KAGAKU, vol. 65, No. 4, pp. 203-209 (2016); H. YOKOYAMA et al., Molecular Crystals and Liquid Crystals, vol. 107, issue 3-4, pp. 311-331, "Measurement of Director Orientation at the Nematic-Isotropic Interface Using a Substrate-Nucleated Nematic Film"). This allows for a lower voltage, i.e., a lower drive voltage, required to control the movement of the liquid crystal molecules.

[0036] 2, the first phase separation layer 19 has a thickness that extends from the first main surface 11S of the first substrate 11 to a height lower than the protruding tip 17A of the first projection 17. Therefore, the first projection 17 rising from the first main surface 11S is immersed in the first phase separation layer 19 from the protruding base end 17B to a height lower than the protruding tip 17A, and the protruding tip 17A is immersed in the liquid crystal layer 13. The second phase separation layer 20 has a thickness that extends from the second main surface 12S of the second substrate 12 to a height lower than the protruding tip 18A of the second projection 18. Therefore, the second projection 18 rising from the second main surface 12S is immersed in the second phase separation layer 20 from the protruding base end 18B to a height lower than the protruding tip 18A, and the protruding tip 18A is immersed in the liquid crystal layer 13. In this way, compared to a case where each of the protrusions 17, 18 is immersed in the liquid crystal layer 13 from each of the main surfaces 11S, 12S to each of the protrusion tips 17A, 18A, the anchoring of the liquid crystal molecules is weakened by the amount that each of the phase separation layers 19, 20 contacts the liquid crystal layer 13. This allows the driving voltage to be lowered. Furthermore, because each of the protrusion tips 17A, 18A of each of the protrusions 17, 18 is immersed in the liquid crystal layer 13, a pretilt angle can be imparted to the liquid crystal molecules.

[0037] Furthermore, since the protrusions 17, 18 rise along axes AX1, AX2 inclined with respect to the main surfaces 11S, 12S, a pretilt can be imparted to the liquid crystal molecules compared to when the protrusions 17, 18 rise along the normal (Z-axis direction) to the main surfaces 11S, 12S. In addition, since the protrusions 17, 18 include protrusions 17, 18 that are in contact with each other, the alignment of the liquid crystal molecules can be stabilized while maintaining weak anchoring to the liquid crystal molecules.

[0038] Furthermore, the rising heights H1, H2 of the protrusions 17, 18 from the main surfaces 11S, 12S are greater than the intervals P1, P2 between adjacent protrusions 17, 18, and therefore the protrusions 17, 18 are more likely to be kept in contact with each other than if the rising heights of the protrusions 17, 18 were the same as or smaller than the intervals P1, P2 between adjacent protrusions 17, 18. This is advantageous in stabilizing the alignment of the liquid crystal molecules while maintaining weak anchoring to the liquid crystal molecules.

[0039] Next, to verify the superiority of the liquid crystal panel 10 according to this embodiment, Comparative Experiment 1 was conducted. In Comparative Experiment 1, the relationship between the voltage applied to the liquid crystal layer and the light transmittance of each liquid crystal panel according to Example 1 and Comparative Example 1 was measured, i.e., the VT (Voltage-Transmittance) characteristic. Example 1 is a liquid crystal panel 10 having the configuration described above. Comparative Example 1 has a configuration in which a polyimide alignment film is provided on the inner surface of each substrate. It differs from Example 1 in the material of the alignment film, the absence of protrusions 17 and 18, and the absence of phase separation layers 19 and 20. The alignment film provided in the liquid crystal panel according to Comparative Example 1 is a vertical alignment film. In Comparative Experiment 1, a voltage was applied to each liquid crystal layer in each liquid crystal panel according to Example 1 and Comparative Example 1, and polarized light from an experimental backlight device was irradiated perpendicular to the tilt orientation of the liquid crystal, and the light transmittance was measured. The experimental results of Comparative Experiment 1 are shown in FIG. 7. 7 is a graph in which the vertical axis represents light transmittance (unit: "%)" and the horizontal axis represents voltage applied to the liquid crystal layer (unit: "Vrms"). In Fig. 7, the experimental results of Example 1 are shown by a solid line, and the experimental results of Comparative Example 1 are shown by a dashed line.

[0040] The results of Comparative Experiment 1 will be explained. According to FIG. 7, it can be said that Example 1 tends to require a lower voltage to obtain the same light transmittance compared to Comparative Example 1. In other words, Example 1 requires a lower driving voltage than Comparative Example 1. It is presumed that this result is due to the fact that the liquid crystal panel 10 of Example 1 has the phase separation layers 19 and 20 and the alignment films 15 and 16 are provided with the protrusions 17 and 18, which weaken the anchoring acting on the liquid crystal molecules.

[0041] Next, the following Comparative Experiment 2 was conducted to verify the superiority of the liquid crystal panel 10 according to this embodiment. In Comparative Experiment 2, the relationship between the position in the Z-axis direction (the normal direction of each main surface of each substrate) in the liquid crystal layer and the pretilt angle of the liquid crystal molecules was determined for each liquid crystal panel according to the following Examples 2 and 3 and Comparative Example 2. Examples 2 and 3 have the same configuration as Example 1 of the above-mentioned Comparative Experiment 1, but have different anchoring energies. Specifically, Example 2 has an anchoring energy of 5×10−5 J / m 2 In Example 3, the anchoring energy is 2.5 × 10-5 J / m 2 The anchoring energy is lower than that of Example 2. Comparative Example 2 has the same configuration as Comparative Example 1 of the above-mentioned Comparative Experiment 1, and the anchoring energy is 1×10 −4 J / m 2 In other words, Comparative Example 2 has a higher anchoring energy than Example 2. In Comparative Experiment 2, for each liquid crystal panel according to Examples 2 and 3 and Comparative Example 2, the pretilt angle of the liquid crystal molecules was measured at each position in the Z-axis direction in the liquid crystal layer without applying a voltage to each liquid crystal layer. Since the pretilt angles of all liquid crystal molecules are not the same even at the same position in the Z-axis direction in the liquid crystal layer, in Comparative Experiment 2, the range from the maximum to the minimum pretilt angle was obtained at each position in the Z-axis direction in the liquid crystal layer. The results of Comparative Experiment 2 are as shown in FIGS. 8 to 10. FIG. 8 shows the experimental results of Comparative Example 2, FIG. 9 shows the experimental results of Example 2, and FIG. 10 shows the experimental results of Example 3. FIGS. 8 to 10 are graphs in which the vertical axis represents the pretilt angle of the liquid crystal molecules (unit: degrees) and the horizontal axis represents the position in the Z-axis direction in the liquid crystal layer (unitless). The vertical axis in Figures 8 to 10 ranges from 0 to 90 degrees, with "0 degrees" representing horizontal alignment and "90 degrees" representing vertical alignment. The horizontal axis in Figures 8 to 10 is a relative value ranging from 0 to 1, with "0" representing the position of the first main surface of the first substrate and "1" representing the position of the second main surface of the second substrate.

[0042] The results of Comparative Experiment 2 will be explained. From FIGS. 8 to 10, it can be seen that, compared to Comparative Example 2, Examples 2 and 3 tend to have smaller minimum pretilt angles closer to the major surfaces of the substrates ("0" and "1" on the horizontal axis). Furthermore, compared to Example 2, Example 3 has smaller minimum pretilt angles in the ranges of 0 to 0.25 and 0.75 to 1 on the horizontal axis. Thus, it can be said that the lower the anchoring energy, the smaller the minimum pretilt angle near the major surfaces of the substrates, and the more liquid crystal molecules tend to be horizontally aligned. The more liquid crystal molecules are horizontally aligned near the major surfaces of the substrates, the lower the voltage applied to the liquid crystal layer to move the liquid crystal molecules. In other words, it can be said that the lower the anchoring energy, the more the driving voltage can be reduced.

[0043] Next, to verify the superiority of the liquid crystal panel 10 according to this embodiment, the following Comparative Experiment 3 was conducted. In Comparative Experiment 3, the pretilt angle of the liquid crystal molecules was determined for each of the liquid crystal panels according to Examples 2 and 3 and Comparative Example 2 of Comparative Experiment 2 described above. More specifically, in Comparative Experiment 3, the pretilt angle of the liquid crystal molecules on the first main surface of the first substrate and the pretilt angle of the liquid crystal molecules at a position 0.5 μm away from the first main surface of the first substrate were measured for each of the liquid crystal panels according to Examples 2 and 3 and Comparative Example 2, with no voltage applied to each liquid crystal layer. The experimental results of Comparative Experiment 3 are as shown in FIG. 11. In FIG. 11, the vertical axis represents the pretilt angle of the liquid crystal molecules (unit: degree) and the horizontal axis represents the anchoring energy (unit: J / m 2 The vertical axis of FIG. 11 is in the range of 0 degrees to 80 degrees. The graph shown in FIG. 11 shows the results when the anchoring energy is 5×10-5J / m 2 The plot of Example 2, which is said to have an anchoring energy of 2.5 × 10 J / m 2 The plot of Example 3 shows the results of the anchoring energy of 1×10 J / m 211 is a line graph connecting Comparative Example 1, which is a comparative example 2, and Comparative Example 3. The measurement results for the first main surface of the first substrate are shown in Fig. 11 as a solid line graph with "0 µm" in the legend, since the distance from the first main surface of the first substrate is 0 µm. Also, the measurement results at a position 0.5 µm away from the first main surface of the first substrate are shown in Fig. 11 as a dashed line graph with "0.5 µm" in the legend.

[0044] The results of Comparative Experiment 3 are now described. According to FIG. 11 , in all of Examples 2 and 3 and Comparative Example 2, the pretilt angle of the liquid crystal molecules tends to be smaller at a position 0 μm away from the first main surface of the first substrate than at a position 0.5 μm away from the first main surface of the first substrate. This is presumably because the anchoring force of the first protrusions of the first alignment film becomes stronger as the position approaches the first main surface of the first substrate, resulting in a pretilt angle of the liquid crystal molecules closer to vertical alignment. Furthermore, Example 2 exhibits a smaller pretilt angle of the liquid crystal molecules than Comparative Example 2, regardless of the distance from the first main surface of the first substrate. In Example 2, the difference between the pretilt angle at a position 0 μm away from the first main surface of the first substrate and the pretilt angle at a position 0.5 μm away from the first main surface of the first substrate is smaller than in Comparative Example 2. From this, it can be said that in Example 2, more liquid crystal molecules are horizontally aligned near the first major surface of the first substrate than in Comparative Example 2, thereby enabling a reduction in drive voltage. Furthermore, in Example 3, the pretilt angle of the liquid crystal molecules is smaller than in Example 2, regardless of the distance from the first major surface of the first substrate. In particular, in Example 3, the difference between the pretilt angle at a position 0 μm away from the first major surface of the first substrate and the pretilt angle at a position 0.5 μm away from the first major surface of the first substrate is reduced to less than half compared to Example 2. From this, it can be said that in Example 3, more liquid crystal molecules are horizontally aligned near the first major surface of the first substrate than in Example 2, thereby enabling a reduction in drive voltage. It is presumed that the results shown in FIG. 11 would be similar to those shown in FIG. 11 if the pretilt angles of the liquid crystal molecules were measured at a position 0 μm away from the second major surface of the second substrate and at a position 0.5 μm away from the second major surface of the second substrate.

[0045] Next, we will explain the relationship between anchoring energy W and the liquid crystal delay time τ0 based on Fig. 3 (referred to as Fig. 12 in this specification) in Xiangyi Nie et al., Journal of Applied Physics 101, 103110 (2007), "Anchoring energy and cell gap effects on liquid crystal response time." The graph in Fig. 12 is a transcription of Fig. 3 in the aforementioned paper, with the vertical axis representing the liquid crystal delay time τ0 (unit: ms) and the horizontal axis representing the cell gap (unit: μm). Fig. 12 shows the results calculated using the "effective cell gap method" and the "surface dynamic equation method" for several samples with different anchoring energy strengths. In Fig. 12, the results calculated using the "effective cell gap method" are shown by the solid plots and solid line, and the results calculated using the "surface dynamic equation method" are shown by the open plots and dashed line. In Figure 12, the anchoring energy W is 1×10-3J / m 2 The plots are marked with "★" or "☆" and are 1×10-4J / m 2 The plot is marked with "◆" or "◇" and is 5×10-5J / m 2 The plots are marked with "●" or "○", and the 2 The plot is displayed as "▼" or "▽", and the 2 The plots are marked as "■" or "□".

[0046] According to Figure 12, the stronger the anchoring energy W, the shorter the delay time τ0 of the liquid crystal, and the weaker the anchoring energy W, the longer the delay time τ0 of the liquid crystal. 2 If the anchoring energy W is less than 5×10-5J / m 2Compared to the above cases, the delay time τ0 of the liquid crystal is significantly longer. Therefore, the anchoring energy W is 5×10-5J / m 2 The above conditions are suitable for ensuring a response speed of the liquid crystal that is sufficient for practical use.

[0047] Next, we will explain the relationship between the pretilt angle of the liquid crystal and the content of PDMS (dimethylpolysiloxane) in the alignment film based on Fig. 6 (Fig. 13 in this specification) in "Control of liquid crystal pretilt angles by using organic / inorganic hybrid interpenetrating networks" by Dowon Ahn et al., September 14, 2009 / Vol. 17, No. 19 / OPTICS EXPRESS 16603-16612. The graph shown in Fig. 13 is a transcription of Fig. 6 in the above-mentioned paper, with the vertical axis representing the pretilt angle of the liquid crystal (unit: degree) and the horizontal axis representing the content of PDMS in the alignment film (unit: %).

[0048] 13, it can be seen that the pretilt angle of the liquid crystal tends to increase as the PDMS content in the alignment film increases. In particular, when the PDMS content in the alignment film exceeds 15%, the pretilt angle of the liquid crystal saturates at an angle close to 90 degrees. Thus, by incorporating PDMS at a content of 15% or more as a material for the alignment film, it becomes easier to align the liquid crystal molecules vertically.

[0049] Next, we will explain the relationship between temperature and the concentration of the liquid crystal E7 based on Fig. 1 (referred to as Fig. 14 in this specification) in "Phase diagrams of poly(dimethylsiloxane) / E7 mixtures" by Nicolas Gogibus et al., European Polymer Journal 37 (2001) 1079-1082. The graph in Fig. 14 is a transcription of Fig. 1 from the aforementioned paper, with the vertical axis representing the liquid crystal temperature (unit: °C) and the horizontal axis representing the liquid crystal E7 concentration (unit: %). Fig. 14 plots the phase transition temperatures of a liquid crystal layer containing the liquid crystal E7 and PDMS (dimethylpolysiloxane). In Fig. 14, "N" refers to the nematic phase, and "I" refers to the isotropic phase. In Fig. 14, the starting point of the transition from (N + I) to (I + I) is indicated by a "◇" and the end point by a "♦." In FIG. 14, the starting point of the transition from (I+I) to I is indicated by a circle, and the end point is indicated by a black circle.

[0050] 14, it can be said that there is not much change in the phase transition temperatures regardless of the concentration of liquid crystal E7. Because the concentration of liquid crystal E7 is inversely correlated with the concentration of PDMS, it can also be said that there is not much change in the phase transition temperatures regardless of the concentration of PDMS. This means that no matter how much PDMS is contained in the liquid crystal layer, there is not much change in the phase transition temperatures. It can be said that PDMS is not compatible with liquid crystal E7 in a temperature environment below a certain phase transition temperature, regardless of the PDMS concentration.

[0051] The liquid crystal panel 10 according to this embodiment has the above-described structure. A method for manufacturing the liquid crystal panel 10 will now be described. The method for manufacturing the liquid crystal panel 10 includes a first substrate manufacturing process for manufacturing the first substrate 11, a second substrate manufacturing process for manufacturing the second substrate 12, and a bonding process for bonding the manufactured first substrate 11 and second substrate 12 together so that the liquid crystal layer 13 is sandwiched between them. The first substrate manufacturing process includes at least a first alignment film forming process for providing a first alignment film 15 and a first phase separation layer forming process for providing a first phase separation layer 19. The second substrate manufacturing process includes at least a second alignment film forming process for providing a second alignment film 16 and a second phase separation layer forming process for providing a second phase separation layer 20. The first alignment film forming process and the first phase separation layer forming process will be described below with reference to FIGS. 15 to 20. The second alignment film forming process and the second phase separation layer forming process are also performed in the same manner as the first alignment film forming process and the first phase separation layer forming process described below.

[0052] In the first alignment film forming process, as shown in FIG. 15, a material 15M (polymer material) for the first alignment film 15 is dropped onto a stamp substrate 21. The stamp substrate 21 has a porous structure with numerous pores formed on its surface, for example, by anodizing a metal plate. Therefore, the surface of the stamp substrate 21 has an uneven surface 21A with fine irregularities. In the first alignment film forming process, the material 15M for the first alignment film 15 is dropped onto the uneven surface 21A of the stamp substrate 21, and the stamp substrate 21 is bonded to the first substrate 11. The material 15M for the first alignment film 15 is sandwiched between the bonded substrates 11 and 21. In this state, as shown in FIG. 16, the substrates 11 and 21 are enclosed in a bag-shaped vacuum packing member 22, and the vacuum packing member 22 is evacuated. Then, ultraviolet light is irradiated onto the substrates 11 and 21 from outside the vacuum packing member 22. At this time, for example, ultraviolet light with a wavelength of 365 nm is irradiated at 20 mW / cm 2 The material 15M of the first alignment film 15 is irradiated with ultraviolet light for a predetermined period of time, and a light quantity of about 2 J is applied to both substrates 11 and 21. By irradiating the ultraviolet light in this manner, the material 15M of the first alignment film 15 is cured.

[0053] In the first alignment film forming process, the substrates 11 and 21 are then removed from the vacuum packing member 22, and the stamp substrate 21 is peeled off from the first substrate 11. As a result, as shown in FIG. 17 , the first alignment film 15 is provided on the first substrate 11. The textured surface 21A of the stamp substrate 21 is transferred to the surface of the first alignment film 15. As a result, a plurality of first protrusions 17 are easily provided in an upright position on the first main surface 11S of the first alignment film 15. At this stage, the plurality of first protrusions 17 are upright in the normal direction to the first main surface 11S. In this way, in this embodiment, the height H1, thickness D1, arrangement interval P1, etc. of the first protrusions 17 can be easily controlled by appropriately adjusting the shape of the textured surface 21A of the stamp substrate 21.

[0054] In the first alignment film forming step, the first alignment film 15 includes a plurality of first protrusions 17 extending from the first main surface 11S, which are then subjected to a rubbing process as shown in FIG. 18. The rubbing process uses a rubbing roller 23 that can rotate about an axis of rotation parallel to the first main surface 11S. When performing the rubbing process, the first substrate 11 is displaced toward the rubbing roller 23, and the rubbing roller 23 is rotated counterclockwise. When the rubbing roller 23 rubs against the first protrusions 17, the first protrusions 17 are tilted. As a result, the plurality of first protrusions 17 are plastically deformed to assume a posture inclined toward the same side with respect to the first main surface 11S (a posture along the first axis AX1), as shown in FIG. 19, and adjacent first protrusions 17 are in contact with each other with an interval P1 therebetween. By performing the first alignment film formation process as described above, the first alignment film 15 is provided, in which the multiple first protrusions 17 are oriented along the first axis AX1. In this way, when providing the first alignment film 15, the multiple first protrusions 17 are arranged at intervals P1 and are raised from the first main surface 11S, thereby imparting anisotropy to the surface energy of the first main surface 11S. Furthermore, by performing a rubbing treatment, the multiple first protrusions 17 rise along the first axis AX1 tilted relative to the first main surface 11S, thereby achieving a pretilt. This allows the driving voltage to be reduced. Additionally, by performing a rubbing treatment on the multiple first protrusions 17, the multiple first protrusions 17 can include first protrusions 17 that are in contact with each other, thereby stabilizing the alignment of the liquid crystal molecules while maintaining weak anchoring to the liquid crystal molecules.

[0055] Thereafter, when the first phase separation layer forming step is performed, a first phase separation layer 19 is provided on the first main surface 11S of the first substrate 11, as shown in FIG. 20 . To provide the first phase separation layer 19, for example, the first main surface 11S is impregnated with the material for the first phase separation layer 19, and then unnecessary material is removed by spin coating, thereby providing the first phase separation layer 19 that is lower than the first protrusions 17. Alternatively, to provide the first phase separation layer 19, for example, the material for the first phase separation layer 19 is ejected onto the first main surface 11S from an inkjet device, thereby providing the first phase separation layer 19 that is lower than the first protrusions 17. In this way, by providing the first phase separation layer 19 on the first main surface 11S of the first substrate 11, the anchoring that the first phase separation layer 19 exerts on the liquid crystal molecules at the interface between the first phase separation layer 19 and the liquid crystal layer 13 is weakened compared to when the first phase separation layer 19 is not present. This allows the drive voltage to be reduced.

[0056] As described above, the liquid crystal panel 10 of this embodiment comprises substrates 11 and 12 having main surfaces 11S and 12S with anisotropic surface energy, a liquid crystal layer 13 made of a liquid crystal material, and phase separation layers 19 and 20 arranged between the main surfaces 11S and 12S and the liquid crystal layer 13 and phase-separated from the liquid crystal layer 13.

[0057] Because the major surfaces 11S, 12S of the substrates 11, 12 have anisotropic surface energies, the liquid crystal molecules contained in the liquid crystal layer 13 are aligned with a predetermined pretilt angle. Because the phase separation layers 19, 20 that are phase-separated from the liquid crystal layer 13 are disposed between the major surfaces 11S, 12S of the substrates 11, 12 and the liquid crystal layer 13, the anchoring acting on the liquid crystal molecules from the phase separation layers 19, 20 at the interfaces between the phase separation layers 19, 20 and the liquid crystal layer 13 is weaker than if the phase separation layers 19, 20 were not present. This allows the voltage (driving voltage) required to control the movement of the liquid crystal molecules to be lowered.

[0058] The liquid crystal display further includes alignment films 15 and 16 having principal surfaces 11S and 12S. The alignment films 15 and 16 are made of a polymer material and have multiple protrusions 17 and 18 arranged at intervals P1 and P2 within the principal surfaces 11S and 12S and protruding from the principal surfaces 11S and 12S toward the liquid crystal layer 13. The phase separation layers 19 and 20 have a thickness extending from the principal surfaces 11S and 12S to a height lower than the protruding tips 17A and 18A of the protrusions 17 and 18. The alignment films 15 and 16 have anisotropic surface energy due to the multiple protrusions 17 and 18 arranged at intervals P1 and P2. The protrusions 17 and 18 rising from the principal surfaces 11S and 12S are immersed in the phase separation layers 19 and 20 to a height lower than the protrusion tips 17A and 18A from the principal surfaces 11S and 12S. Compared to the case where the protrusions 17, 18 are immersed in the liquid crystal layer 13 from the main surfaces 11S, 12S to the protrusion tips 17A, 18A, the anchoring of the liquid crystal molecules is weakened by the amount of contact between the phase separation layers 19, 20 and the liquid crystal layer 13. This allows the driving voltage to be lowered. Furthermore, because the protrusion tips 17A, 18A of the protrusions 17, 18 are immersed in the liquid crystal layer 13, a pretilt angle can be imparted to the liquid crystal molecules.

[0059] Furthermore, the multiple protrusions 17, 18 rise along axes AX1, AX2 tilted with respect to the major surfaces 11S, 12S, and some of the multiple protrusions 17, 18 are in contact with one another. In this way, the multiple protrusions 17, 18 rise along axes AX1, AX2 tilted with respect to the major surfaces 11S, 12S, thereby obtaining a pretilt. This allows the driving voltage to be reduced. In addition, since the multiple protrusions 17, 18 include some protrusions 17, 18 in contact with one another, the alignment of the liquid crystal molecules can be stabilized while maintaining weak anchoring to the liquid crystal molecules.

[0060] Furthermore, the rising heights H1, H2 of the multiple protrusions 17, 18 from the main surfaces 11S, 12S are greater than the intervals P1, P2 between adjacent protrusions 17, 18. This increases the reliability of maintaining the protrusions 17, 18 in contact with each other compared to when the rising heights H1, H2 of the protrusions 17, 18 are the same as or smaller than the intervals P1, P2 between adjacent protrusions 17, 18. This is advantageous in stabilizing the alignment of the liquid crystal molecules while maintaining weak anchoring to the liquid crystal molecules.

[0061] Furthermore, the alignment films 15 and 16 contain polydimethylsiloxane, which weakens the anchoring effect on the liquid crystal molecules from the phase separation layers 19 and 20. This is advantageous for lowering the drive voltage.

[0062] Furthermore, the phase separation layers 19 and 20 contain polydimethylsiloxane, which weakens the anchoring effect on the liquid crystal molecules from the phase separation layers 19 and 20. This is advantageous for lowering the driving voltage.

[0063] The liquid crystal layer 13 is a dichroic liquid crystal layer containing a dichroic dye. By applying an electric field to the dichroic liquid crystal layer and controlling the orientation of the liquid crystal molecules, it is possible to transmit light or to have the light absorbed by the dichroic dye contained in the dichroic liquid crystal layer.

[0064] The manufacturing method of the liquid crystal panel 10 according to this embodiment involves imparting anisotropy to the surface energy of the main surfaces 11S and 12S of the substrates 11 and 12, providing phase separation layers 19 and 20 on the main surfaces 11S and 12S, and providing a liquid crystal layer 13 sandwiching the phase separation layers 19 and 20 between the main surfaces 11S and 12S.

[0065] By imparting anisotropy to the surface energies of the major surfaces 11S, 12S of the substrates 11, 12, the liquid crystal molecules contained in the liquid crystal layer 13 are oriented with a predetermined pretilt angle. By providing phase separation layers 19, 20 on the major surfaces 11S, 12S of the substrates 11, 12 and providing the liquid crystal layer 13 with the phase separation layers 19, 20 sandwiched between them, the anchoring acting on the liquid crystal molecules from the phase separation layers 19, 20 at the interfaces between the phase separation layers 19, 20 and the liquid crystal layer 13 is weakened compared to when the phase separation layers 19, 20 are not present. This allows the voltage (driving voltage) required to control the movement of the liquid crystal molecules to be lowered.

[0066] Furthermore, alignment films 15, 16 having principal surfaces 11S, 12S and made of a polymer material are provided. When providing the alignment films 15, 16, multiple protrusions 17, 18 are provided that are aligned at intervals P1, P2 within the principal surfaces 11S, 12S and rise from the principal surfaces 11S, 12S, and then a rubbing treatment is performed on the multiple protrusions 17, 18, causing the multiple protrusions 17, 18 to rise along axes AX1, AX2 tilted with respect to the principal surfaces 11S, 12S, and some of the multiple protrusions 17, 18 are in contact with each other. When providing the alignment films 15, 16, providing the multiple protrusions 17, 18 that are aligned at intervals P1, P2 and rise from the principal surfaces 11S, 12S makes it possible to impart anisotropy to the surface energy of the principal surfaces 11S, 12S. When the multiple protrusions 17, 18 are subjected to rubbing treatment, the multiple protrusions 17, 18 stand up along axes AX1, AX2 that are inclined with respect to the main surfaces 11S, 12S, thereby obtaining a pretilt. In addition, when the multiple protrusions 17, 18 are subjected to rubbing treatment, the multiple protrusions 17, 18 can include protrusions 17, 18 that are in contact with each other, thereby stabilizing the alignment of the liquid crystal molecules while maintaining weak anchoring to the liquid crystal molecules.

[0067] Furthermore, when providing the alignment films 15, 16, the material for the alignment films 15, 16 is applied to the textured surface 21A of the stamp substrate 21, which has the textured surface 21A. The stamp substrate 21 is then bonded to the substrates 11, 12, the material for the alignment films 15, 16 is brought into contact with the substrates 11, 12, the material for the alignment films 15, 16 is cured, and the stamp substrate 21 is then peeled off from the substrates 11, 12. When the stamp substrate 21 is peeled off from the substrates 11, 12, the shape of the textured surface 21A is transferred, making it easy to provide the alignment films 15, 16 having the multiple protrusions 17, 18. By appropriately adjusting the shape of the textured surface 21A of the stamp substrate 21, the heights H1, H2, thicknesses D1, D2, arrangement intervals P1, P2, etc. of the protrusions 17, 18 can be easily controlled.

[0068] <Embodiment 2> Embodiment 2 will be described with reference to Fig. 21 or 22. In this embodiment 2, a partition wall 24 is provided instead of the alignment films 15 and 16 described in embodiment 1. Note that a redundant description of the structure, action, and effect similar to those of embodiment 1 will be omitted. In this embodiment, the first substrate 111 is shown as a representative, but the second substrate 12 (see Fig. 2) also has a similar configuration.

[0069] As shown in FIG. 21 , the first substrate 111 according to this embodiment is provided with partition walls 24 that partition the first main surface 111S into a plurality of partitioned regions PA. In FIG. 21 , the areas where the partition walls 24 are formed are shown shaded. Specifically, the partition walls 24 are lattice-shaped in a plan view, partitioning the first main surface 111S in a grid pattern, and each of the partitioned partitioned regions PA has a substantially square planar shape. The partition walls 24 are configured such that a portion extending along the X-axis direction and a portion extending along the Y-axis direction are connected to each other at their intersecting positions. The width of the partition walls 24 is, for example, 5 μm. The partitioned regions PA partitioned by the partition walls 24 each have a dimension of, for example, about 50 μm in the X-axis direction and a dimension of, for example, about 50 μm in the Y-axis direction. As shown in FIG. 22 , the partition walls 24 rise from the first main surface (main surface) 111S toward the liquid crystal layer 13 (see FIG. 2 ). The partition walls 24 have a height of, for example, about 1 μm from the first main surface 111S. Because the first main surface 111S is divided into a plurality of partition regions PA by these partition walls 24, the first phase separation layer (phase separation layer) 119 is composed of a plurality of first divided phase separation layers (divided phase separation layers) 119S arranged in the plurality of partition regions PA. The partition walls 24 prevent the plurality of first divided phase separation layers 119S arranged in the plurality of partition regions PA from moving outside the partition region PA to which they belong. This allows the first divided phase separation layers 119S to be kept in each partition region PA to which they belong, preventing deviation of the alignment film due to external stimuli.

[0070] The partition walls 24 are made of, for example, the "ATX (registered trademark) series" oil-repellent photoresist manufactured by AGC Corporation. Therefore, as shown in FIG. 22, a liquid-repellent layer (water- and oil-repellent layer) 25 is formed on the rising end surfaces 24A of the partition walls 24 extending from the first main surface 111S. The liquid-repellent layer 25 repels the material of the first phase separation layer 119, making it less likely that the material of the first phase separation layer 119 will remain on the rising end surfaces 24A of the partition walls 24. The rising end surfaces 24A of the partition walls 24 are also subjected to an alignment treatment. This allows the rising end surfaces 24A of the partition walls 24 to impart a pretilt angle to the liquid crystal molecules contained in the liquid crystal layer 13. This embodiment is suitable for cases where it is difficult to provide structures (protrusions 17 and 18 of Embodiment 1) for imparting a pretilt angle to the liquid crystal molecules within the partition regions PA when the partition regions PA are minimized by the partition walls 24. In addition, in this embodiment, the material of the first phase separation layer 119 is made by dissolving a surfactant in water, and as the surfactant, for example, "DTAB (Dodecyltrimethylammonium bromide)" manufactured by Sigma-Aldrich Japan LLC can be used.

[0071] As described above, according to this embodiment, the liquid crystal display device includes partition walls 24 that rise from the first main surface (main surface) 111S toward the liquid crystal layer 13 and partition the first main surface 111S into a plurality of partitioned regions PA, and the first phase separation layer (phase separation layer) 119 is made up of a plurality of first divided phase separation layers (divided phase separation layers) 119S that are arranged in the plurality of partitioned regions PA. The partition walls 24 prevent the plurality of first divided phase separation layers 119S arranged in the plurality of partitioned regions PA from moving outside the partitioned region PA to which they belong. This allows the first divided phase separation layers 119S to be confined to the respective partitioned regions PA to which they belong, thereby preventing deviation of the alignment layer due to external stimuli at the interface between the first divided phase separation layers 119S and the liquid crystal layer 13.

[0072] Moreover, the partition walls 24 have their tip surfaces 24A that rise from the first main surface 111S subjected to alignment treatment. The tip surfaces 24A of the partition walls 24 can impart a pretilt angle to the liquid crystal molecules contained in the liquid crystal layer 13. This is suitable when it is difficult to provide a structure for imparting a pretilt angle to the liquid crystal molecules in the partition areas PA when the partition walls 24 minimize the partition areas PA.

[0073] <Embodiment 3> A third embodiment will be described with reference to Figure 23. This third embodiment shows a case where the configuration of the partition wall 224 is changed from that of the second embodiment. Note that redundant explanations of the structure, action, and effect similar to those of the second embodiment will be omitted. In this embodiment, the first substrate 211 is shown as a representative, but the second substrate 12 (see Figure 2) also has a similar configuration.

[0074] As shown in FIG. 23 , the partition wall 224 according to this embodiment is configured such that the width of a portion extending along the Y-axis direction varies depending on the position in the Y-axis direction. In FIG. 23 , the formation area of ​​the partition wall 224 is illustrated by a shaded area. Specifically, the side surface 224B of the portion of the partition wall 224 extending along the Y-axis direction is inclined with respect to the Y-axis direction in a plan view. Therefore, the partitioned area PA defined by the partition wall 224 has a substantially inverted trapezoidal planar shape, and is asymmetric in a plan view with respect to a line along the X-axis direction that passes through the center position in the Y-axis direction. In the partitioned area PA, some liquid crystal molecules are aligned along the side surface 224B of the partition wall 224 that is inclined with respect to the Y-axis direction. By configuring the partition wall 224 so that the planar shape of the partitioned area PA is asymmetric as described above, anisotropy is imparted to the surface energy of the first major surface 211S, and as a result, the liquid crystal molecules in the partitioned area PA are aligned with a predetermined pretilt angle. This embodiment is suitable for cases where it is difficult to provide structures (protrusions 17 and 18 in Embodiment 1) for imparting a pretilt angle to liquid crystal molecules within the partitioned regions PA when the partitioned regions PA are minimized by the partition walls 224. Furthermore, the partition walls 224 prevent the plurality of first divided phase separation layers 219S constituting the phase separation layer 219 from moving outside the partitioned regions PA to which they belong.

[0075] As described above, according to this embodiment, the partition walls 224 are configured so that the planar shape of the partition areas PA is asymmetric. In the partition areas PA, the liquid crystal molecules contained in the liquid crystal layer 13 are aligned along the side surfaces 224B of the partition walls 224. Because the partition walls 224 are configured so that the planar shape of the partition areas PA is asymmetric, anisotropy is imparted to the surface energy of the first main surface 211S, and as a result, the liquid crystal molecules in the partition areas PA are aligned with a predetermined pretilt angle. This is suitable for cases where it is difficult to provide a structure for imparting a pretilt angle to the liquid crystal molecules in the partition areas PA when the partition walls 224 minimize the partition areas PA.

[0076] <Embodiment 4> A fourth embodiment will be described with reference to Fig. 24. In this fourth embodiment, the configuration of the partition wall 324 is changed from that of the third embodiment. Note that redundant explanations of the structure, action, and effect similar to those of the third embodiment will be omitted. In this embodiment, the first substrate 311 is shown as a representative, but the second substrate 12 (see Fig. 2) also has a similar configuration.

[0077] As shown in FIG. 24 , the partition wall 324 according to this embodiment is configured so that the planar shape of the multiple partitioned regions PA is approximately trapezoidal. Note that in FIG. 24 , the area where the partition wall 324 is formed is shaded. Therefore, similar to the third embodiment, the partitioned regions PA are asymmetric in plan view with respect to a line along the X-axis direction that passes through the center position in the Y-axis direction. Note that the partitioned regions PA according to this embodiment have a smaller area in plan view than the partitioned regions PA according to the third embodiment, and therefore provide weaker anchoring to the liquid crystal molecules. Of the partition walls 324, the side surfaces 324B that form the hypotenuses of the approximately trapezoidal partitioned regions PA are inclined with respect to the Y-axis direction in plan view. In the partitioned regions PA, some liquid crystal molecules are aligned along the side surfaces 324B of the partition walls 324 that are inclined with respect to the Y-axis direction. Therefore, in the partitioned regions PA, the liquid crystal molecules are aligned with a predetermined pretilt angle. Furthermore, the partition walls 324 prevent the plurality of first divided phase separation layers 319S constituting the phase separation layer 319 from moving outside the partition area PA to which they belong.

[0078] <Embodiment 5> Embodiment 5 will be described with reference to Fig. 25. In this embodiment 5, an alignment control convex portion (convex portion) 26 having an asymmetric cross section is added to the configuration described in the above-mentioned embodiment 2. Note that a redundant description of the structure, action, and effect similar to those of the above-mentioned embodiment 2 will be omitted. In this embodiment, the first substrate 411 is shown as a representative, but the second substrate 12 (see Fig. 2) also has a similar configuration.

[0079] As shown in Fig. 25, the first substrate 411 according to this embodiment is provided with a plurality of alignment control protrusions 26 in an area overlapping with pixels PX included in the liquid crystal panel 10. Note that in Fig. 25, the alignment control protrusions 26 are illustrated as hatched. Also in Fig. 25, the area of ​​the pixels PX included in the liquid crystal panel 10 is illustrated by a thick two-dot chain line, and the boundaries of a plurality of domains D included in the pixels PX are illustrated by thin two-dot chain lines.

[0080] A plurality of alignment control protrusions 26 are arranged in the area surrounded by the partition walls 24 (see FIG. 21 ) described in the second embodiment, i.e., in the partition area PA. The alignment control protrusions 26 rise from the first major surface 11S toward the liquid crystal layer 13 (see FIG. 2 ) in the partition area PA. The alignment control protrusions 26 are made of the same material as the partition walls 24 and are formed on the first substrate 411 in the same manufacturing process as the partition walls 24. The alignment control protrusions 26 have an overall substantially triangular planar shape, with a height of about 1 μm, the same as the partition walls 24, and a base length of about 7 μm. The alignment control protrusions 26 are configured such that a small triangular portion of similar shape is cut out at the center of the base. The alignment control protrusions 26 with such a planar shape are arranged so as to orient in different directions for each of four domains D, which are obtained by equally dividing the pixel PX. Four orientation control protrusions 26 are arranged in each domain D, and the four orientation control protrusions 26 arranged in one domain D have the same planar shape, and their apexes (the intersection of a pair of oblique sides) are oriented in the same direction.

[0081] The tops of the alignment control protrusions 26 arranged in the domains D are oriented in different directions. Specifically, the tops of the alignment control protrusions 26 arranged in the upper left domain D shown in Fig. 25 are oriented upward in Fig. 25, the tops of the alignment control protrusions 26 arranged in the upper right domain D shown in Fig. 25 are oriented right in Fig. 25, the tops of the alignment control protrusions 26 arranged in the lower right domain D shown in Fig. 25 are oriented downward in Fig. 25, and the tops of the alignment control protrusions 26 arranged in the lower left domain D shown in Fig. 25 are oriented left in Fig. 25. Of the alignment control protrusions 26, the side surface 26A constituting the oblique side in plan view is inclined with respect to the X-axis direction or the Y-axis direction in plan view. In each alignment control protrusion 26, some liquid crystal molecules are aligned along the side surfaces 26A that are inclined with respect to the Y-axis direction. Therefore, in each alignment control protrusion 26, the liquid crystal molecules are aligned with a predetermined pretilt angle. Thus, the multiple alignment control protrusions 26 arranged within the partition wall 24 can be said to have asymmetric cross sections. Because the orientation of the oblique sides (side surfaces 26A) of each alignment control protrusion 26 differs for each domain D, the orientation of the liquid crystal molecules aligned along the side surfaces 26A of each alignment control protrusion 26 differs for each domain D. This allows the liquid crystal panel 10 to operate in a multidomain vertical alignment (MVA) mode, which is suitable for achieving a wide viewing angle. Furthermore, the partition wall 24 prevents the multiple first divided phase separation layers 419S constituting the phase separation layer 419 from moving outside the partition area PA to which they belong (see FIG. 21).

[0082] <Embodiment 6> A sixth embodiment will be described with reference to Fig. 26. In this sixth embodiment, the configuration of the partition wall 524 is changed from that of the second embodiment. Note that redundant explanations of the structure, action, and effect similar to those of the second embodiment will be omitted. In this embodiment, the first substrate 511 is shown as a representative, but the second substrate 12 (see Fig. 2) also has a similar configuration.

[0083] As shown in FIG. 26 , the partition wall 524 according to this embodiment is configured such that the planar shape of each of the partitioned regions PA is a horizontally elongated rectangle. In FIG. 26 , the area in which the partition wall 524 is formed is shaded. The side surfaces 524B of the partition wall 524 include a side surface 524B extending along the X-axis direction and a side surface 524B extending along the Y-axis direction. The side surface 524B extending along the X-axis direction has a larger area facing one partitioned region PA than the side surface 524B extending along the Y-axis direction. Therefore, in the partitioned region PA, liquid crystal molecules oriented along the side surface 524B of the partition wall 524 extending along the X-axis direction predominate. This allows for horizontal alignment of the liquid crystal molecules. The display mode of the liquid crystal panel 10 according to this embodiment can be, for example, a fringe field switching (FFS) mode or an in-plane switching (IPS) mode. Furthermore, the partition walls 524 prevent the plurality of first divided phase separation layers 519S constituting the phase separation layer 519 from moving outside the partition area PA to which they belong.

[0084] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included in the technical scope.

[0085] (1) As a modification of the fifth embodiment, the alignment control protrusions 26-1 may be configured to have a planar shape shown in FIG.

[0086] (2) As a modification of the fifth embodiment, the alignment control protrusions 26-2 may be configured to have a planar shape shown in FIG.

[0087] (3) As a modification of the fifth embodiment, the alignment control protrusions 26-3 may be configured to have a planar shape shown in FIG.

[0088] (4) As a modification of the fifth embodiment, the alignment control protrusions 26-4 may be configured to have a planar shape shown in FIG.

[0089] (5) As a modification of the fifth embodiment, the alignment control protrusions 26-5 may be configured to have a planar shape shown in FIG.

[0090] (6) As a modification of the fifth embodiment, the alignment control protrusions 26-6 may be configured to have a planar shape shown in FIG.

[0091] (7) In the configurations described in the second to sixth embodiments, the alignment films 15 and 16 having the protrusions 17 and 18 described in the first embodiment may be provided.

[0092] (8) As a modification of the third embodiment, the portion of the partition wall 224 extending along the X-axis direction may be configured so that the width varies depending on the position in the X-axis direction.

[0093] (9) As a modification of the third embodiment, the planar shape of the partitioned area PA may be a trapezoid, a rhombus, or the like.

[0094] (10) As a modification of the fourth embodiment, the planar shape of the partitioned area PA may be an inverted trapezoid or a rhombus.

[0095] (11) As a modification of the fifth embodiment, the planar shapes of the alignment control protrusions 26, 26-1, 26-2, 26-3, 26-4, 26-5, and 26-6 can be appropriately changed to shapes other than those shown in Figures 27 to 32 in (1) to (6) above. Furthermore, the configuration described in the fifth embodiment may be combined with the configurations described in the third, fourth, and sixth embodiments.

[0096] (12) As a modification of the sixth embodiment, the planar shape of the partitioned area PA may be a vertically long rectangle.

[0097] (13) In the configuration described in the first embodiment, the specific materials used for the alignment films 15 and 16 can be changed as appropriate to other materials than those mentioned above.

[0098] (14) In the liquid crystal panel 10 and the manufacturing method thereof described in the first embodiment, the material of the alignment films 15 and 16 may contain a thermosetting material, and the material of the alignment films 15 and 16 may be thermally cured during the manufacturing process.

[0099] (15) In the configurations described in the respective embodiments, the specific materials used for the phase separation layers 19, 20, 119, 219, 319, 419, and 519 can be changed as appropriate to those other than those mentioned above.

[0100] (16) In the configurations described in embodiments 2 to 6, the specific materials used for the partition walls 24, 224, 324, and 524 and the alignment control protrusions 26, 26-1, 26-2, 26-3, 26-4, 26-5, and 26-6 can be changed as appropriate to those described above. Also, in the configuration described in embodiment 5, the partition walls 24 and the alignment control protrusions 26, 26-1, 26-2, 26-3, 26-4, 26-5, and 26-6 can be made of different materials.

[0101] (17) In the configurations described in the first to fifth embodiments, the liquid crystal molecules may be horizontally aligned.

[0102] (18) The display mode of the liquid crystal panel 10 may further be a VA (vertical alignment) mode, a PVA (patterned vertical alignment) mode, or the like.

[0103] (19) The liquid crystal panel 10 may include a liquid crystal layer 13 that does not contain a dichroic dye.

[0104] (20) Surface modification can be achieved by selectively irradiating particles with a particle beam. [Explanation of symbols]

[0105] 10... liquid crystal panel, 11,12,111,211,311,411,511... substrate, 11S,12S,111S,211S... main surface, 13... liquid crystal layer, 15,16... alignment film, 17,18... protrusion, 17A,18A... protrusion tip, 19,20,119,219,319,419,519... phase separation layer, 21... stamp substrate, 21A... uneven surface, 24,224,324,524... partition wall, 24A... tip surface, 119S,219S,319S,419S,519S... first divided phase separation layer (divided phase separation layer), AX1, AX2... axis, H1,H2... height, P1,P2... spacing, PA... partition area

Claims

1. a substrate having a main surface with anisotropic surface energy; a liquid crystal layer made of a liquid crystal material; a phase separation layer disposed between the main surface and the liquid crystal layer, the phase separation layer being phase-separated from the liquid crystal layer;

2. an alignment film having the main surface, the alignment film is made of a polymer material and has a plurality of protrusions arranged at intervals within the main surface and protruding from the main surface toward the liquid crystal layer, 2. The liquid crystal panel according to claim 1, wherein the phase separation layer has a thickness extending from the main surface to a height lower than the protruding tip ends of the protrusions.

3. the plurality of protrusions rise along axes inclined with respect to the main surface, 3. The liquid crystal panel according to claim 2, wherein the plurality of protrusions include protrusions that are in contact with each other.

4. 4. The liquid crystal panel according to claim 2, wherein the plurality of protrusions have a height from the main surface that is greater than the distance between adjacent protrusions.

5. 4. The liquid crystal panel according to claim 2, wherein the alignment film contains polydimethylsiloxane.

6. partition walls extending from the main surface toward the liquid crystal layer and dividing the main surface into a plurality of partition regions; 4. The liquid crystal panel according to claim 1, wherein the phase separation layer comprises a plurality of divided phase separation layers arranged in the plurality of partitioned regions.

7. 7. The liquid crystal panel according to claim 6, wherein the partition wall has a plurality of alignment control protrusions, each of which has an asymmetric cross section.

8. 7. The liquid crystal panel according to claim 6, wherein the partition walls have end surfaces that rise from the main surfaces and are subjected to an alignment treatment.

9. 7. The liquid crystal panel according to claim 6, wherein the partition wall is configured so that the planar shape of the partition area is asymmetric.

10. 4. The liquid crystal panel according to claim 1, wherein the phase separation layer contains polydimethylsiloxane.

11. 4. The liquid crystal panel according to claim 1, wherein the liquid crystal layer is a dichroic liquid crystal layer containing a dichroic dye.

12. imparting anisotropy to the surface energy of the main surface of the substrate; providing a phase separation layer on the main surface; A method for manufacturing a liquid crystal panel, comprising providing a liquid crystal layer sandwiching the phase separation layer between the main surface and the liquid crystal layer.

13. providing an alignment film having the main surface and made of a polymer material; 13. The method for manufacturing a liquid crystal panel according to claim 12, wherein when the alignment film is provided, a plurality of protrusions are provided that are spaced apart within the main surface and that rise from the main surface, and then a rubbing treatment is performed on the plurality of protrusions, so that the plurality of protrusions rise along an axis tilted relative to the main surface, and some of the plurality of protrusions are in contact with each other.

14. 14. The method for manufacturing a liquid crystal panel according to claim 13, wherein when the alignment film is provided, a material for the alignment film is applied to the uneven surface of a stamp substrate having an uneven surface, the stamp substrate is then attached to the substrate to bring the material for the alignment film into contact with the substrate, the material for the alignment film is hardened, and then the stamp substrate is peeled off from the substrate.

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