Optical device

Abstract

The optical device includes: a light source; and an optical element that includes a plurality of stacked liquid crystal cells and that controls light distribution of light emitted from the light source, each of the plurality of liquid crystal cells including: a first substrate (110-1) on which first electrodes (120-1) and second electrodes (120-2) are alternately arranged; a second substrate on which a third electrode and a fourth electrode are alternately arranged; and a liquid crystal layer between the first substrate and the second substrate, each of the first electrode and the second electrode including: a first linear portion (LP11) extending at an angle [alpha] DEG with respect to a first direction; and a second linear portion (LP12) extending at an angle [beta] degree with respect to the first direction, each of the third electrode and the fourth electrode including: a third linear portion extending at an angle (90 + [alpha]) degree with respect to the first direction; and a fourth linear portion extending at an angle (90 + beta) degree with respect to the first direction.

Description

Technical Field

[0001] One embodiment of the present invention relates to an optical device that controls light distribution of light emitted from a light source. Background Art

[0002] In the past, there have been known optical elements that utilize the change in the refractive index of liquid crystal by adjusting the voltage applied to liquid crystal, namely, so-called liquid crystal lenses. In addition, the development of optical devices that use liquid crystal lenses to control the light distribution of light emitted from a light source is being promoted (for example, see Patent Documents 1, 2, and 3).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-317879

[0006] Patent Document 2: Japanese Patent Application Publication No. 2010-230887

[0007] Patent Document 3: Japanese Patent Application Publication No. 2014-160277 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] However, if the shapes and configurations of the electrodes for applying voltage to the liquid crystals are the same in the stacked multiple liquid crystal cells, interference fringes, moiré fringes or coloring may sometimes occur in the diffused light. It is also possible to design the shapes and patterns of the electrodes of the stacked multiple liquid crystal cells to be all different, but this will increase the types of liquid crystal cells manufactured, thus increasing the manufacturing cost.

[0010] In view of the above problems, an object of one embodiment of the present invention is to provide an optical device that suppresses manufacturing costs and reduces moire fringes.

[0011] Solutions for solving technical problems

[0012] An optical device according to one embodiment of the present invention includes: a light source; and an optical element, including a plurality of stacked liquid crystal units, for controlling the light distribution of light emitted from the light source, wherein the plurality of liquid crystal units respectively include: a first substrate, on which a first electrode and a second electrode are alternately arranged; a second substrate, on which a third electrode and a fourth electrode are alternately arranged; and a liquid crystal layer between the first substrate and the second substrate, wherein the first electrode and the second electrode respectively include: a first straight portion extending at an angle α° (0<α<90) relative to a first direction; and a second straight portion extending at an angle β° (0<β<90 and β ≠α), the third electrode and the fourth electrode respectively include: a third straight line portion extending at an angle of (90+α)° relative to the first direction; and a fourth straight line portion extending at an angle of (90+β)° relative to the first direction, and the plurality of liquid crystal units include: a first liquid crystal unit configured to be closest to the light source; and a second liquid crystal unit stacked on the first liquid crystal unit, the first substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, and the second liquid crystal unit is overlapped with the first liquid crystal unit in such a way that the angle formed by the first direction of the first liquid crystal unit and the first direction of the second liquid crystal unit is 180°. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic perspective view of an optical device according to one embodiment of the present invention.

[0014] Figure 2 This is a schematic exploded perspective view of an optical element of an optical device according to an embodiment of the present invention.

[0015] Figure 3 This is a schematic perspective view of a first liquid crystal unit of an optical device according to one embodiment of the present invention.

[0016] Figure 4A This is a schematic cross-sectional view of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0017] Figure 4B This is a schematic cross-sectional view of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0018] Figure 5A It is a schematic cross-sectional view for explaining the property of light passing through the first liquid crystal cell of the optical device 1 according to one embodiment of the present invention.

[0019] Figure 5B It is a schematic cross-sectional view for explaining the property of light passing through the first liquid crystal cell of the optical device 1 according to one embodiment of the present invention.

[0020] Fig. 6AThis is a schematic plan view showing a plan pattern of a transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0021] Figure 6B This is a schematic plan view showing a plan pattern of a transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0022] Figure 7 This is a schematic plan view showing a plan pattern of a transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0023] Fig. 8A It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the first liquid crystal cell of the optical device according to one embodiment of the present invention.

[0024] Figure 8B It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the second liquid crystal cell of the optical device according to one embodiment of the present invention.

[0025] Figure 8C It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the second liquid crystal cell of the optical device according to one embodiment of the present invention.

[0026] Fig.8D It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the second liquid crystal cell of the optical device according to one embodiment of the present invention.

[0027] Fig.9A This is a schematic plan view showing an overlapping state of transparent electrodes extending in the x-axis direction in an optical device according to an embodiment of the present invention.

[0028] Fig. 9B This is a schematic plan view showing an overlapping state of transparent electrodes extending in the y-axis direction in the optical device according to one embodiment of the present invention.

[0029] Fig.10 This is a schematic exploded perspective view of an optical element of an optical device according to an embodiment of the present invention.

[0030] Fig.11A It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the third liquid crystal unit of the optical element included in the optical device according to one embodiment of the present invention.

[0031] Fig. 11B It is a schematic diagram for explaining the angle of the extending direction of the transparent electrode of the fourth liquid crystal unit of the optical element included in the optical device according to one embodiment of the present invention.

[0032] Fig.12 This is a schematic plan view showing a plan pattern of a first transparent electrode and a second transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0033] Fig.13 This is a schematic plan view showing a plan pattern of a first transparent electrode and a second transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0034] Fig.14 This is a schematic plan view showing a plan pattern of a first transparent electrode and a second transparent electrode of a first liquid crystal cell of an optical device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Hereinafter, each embodiment of the present invention will be described with reference to the drawings, etc. However, the present invention can be implemented in various forms within the scope of the gist of the technical concept, and is not to be construed as being limited to the description of the following exemplary embodiments.

[0036] In order to make the description clearer, the drawings sometimes schematically show the width, thickness, shape, etc. of each part compared to the actual method, but this is only an example, and the shape of the drawings itself does not limit the interpretation of the present invention. In addition, in the drawings, for elements having the same function as the elements described in the drawings that have appeared in the specification, even in other drawings, the same reference numerals are sometimes marked and repeated descriptions are omitted.

[0037] When a certain film is processed to form multiple structures, sometimes each structure has different functions and effects, and sometimes the substrates forming each structure are different. However, these multiple structures are derived from the film formed into the same layer in the same process and have the same material. Therefore, it is defined that the above-mentioned multiple films exist in the same layer.

[0038] When expressing the manner in which another structure is arranged on a certain structure, when simply expressed as "on", unless otherwise specified, it includes both the case in which the other structure is arranged directly above the certain structure and the case in which the other structure is arranged above the certain structure via another structure.

[0039] <First Implementation Method>

[0040] Reference Figure 1 to Figure 11B , an optical device involved in one embodiment of the present invention is described.

[0041] [1. Structure of optical device]

[0042] Figure 1 1 is a schematic perspective view of an optical device 1 according to an embodiment of the present invention. Figure 1 As shown, the optical device 1 includes an optical element 10 and a light source 20. The structure of the optical element 10 will be described in detail later, and the optical element 10 includes a plurality of liquid crystal cells 100. The optical element 10 controls the diffusion of light emitted from the light source 20 by using a plurality of liquid crystal cells 100, and can change the shape of light passing through the optical element 10, that is, the light distribution.

[0043] The light source 20 is not particularly limited as long as it can emit light. For example, a light emitting diode (LED) or the like can be used as the light source 20 .

[0044] Figure 2 1 is a schematic exploded perspective view of an optical element 10 of an optical device 1 according to an embodiment of the present invention. Figure 2 As shown, the optical element 10 includes four liquid crystal cells 100 (a first liquid crystal cell 100-1, a second liquid crystal cell 100-2, a third liquid crystal cell 100-3, and a fourth liquid crystal cell 100-4). The first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell are sequentially stacked and overlapped along the z-axis direction from the light source 20 side. The first liquid crystal cell 100-1 is closest to the light source 20, and the fourth liquid crystal cell 100-4 is farthest from the light source 20. In addition, the number of liquid crystal cells 100 included in the optical element 10 is not limited to 4. The optical element 10 may include at least two liquid crystal cells 100.

[0045] Each of the four liquid crystal cells 100 includes a connection terminal described below. The connection terminal is connected to a flexible printed circuit board (Flexible Printed Circuits: FPCs) 210 , and a control signal is input to the liquid crystal cell 100 via the flexible printed circuit board 210 .

[0046] The optical elastic resin layer 200 is provided between two adjacent liquid crystal cells 100. That is, the optical element 10 is provided with the optical elastic resin layer 200 between the first liquid crystal cell 100-1 and the second liquid crystal cell 100-2, between the second liquid crystal cell 100-2 and the third liquid crystal cell 100-3, and between the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4. The optical elastic resin layer 200 can bond and fix the two adjacent liquid crystal cells 100. As the optical elastic resin layer 200, for example, an adhesive material containing a light-transmitting acrylic resin can be used.

[0047] Figure 1 as well as Figure 2The x-axis, y-axis, and z-axis shown are defined based on the optical element 10 and are orthogonal to each other. The z-axis direction is the stacking direction of the plurality of liquid crystal cells 100, and the direction away from the light source 20 is the + direction. The x-axis direction and the y-axis direction are each a direction of a plane perpendicular to the z-axis.

[0048] The first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 have the same structure. That is, in the optical element 10, the four liquid crystal units 100 having the same structure are stacked with their arrangement directions changed. Figure 2 As shown, the first direction D1 and the second direction D2 of the first liquid crystal unit 100-1 correspond to the x-axis direction (+x direction) and the y-axis direction (+y direction) of the optical element 10, respectively. In the following, for convenience, when describing the respective arrangement directions of the four liquid crystal units 100 having the same structure, the arrangement direction of the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 are described based on the arrangement direction of the first liquid crystal unit 100-1 closest to the light source 20.

[0049] The first direction D1 and the second direction D2 of the second liquid crystal unit 100-2 are respectively the -x direction and the -y direction. In other words, the second liquid crystal unit 100-2 is arranged on the first liquid crystal unit 100-1 in such a manner that the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the second liquid crystal unit 100-2 is 180°, and the angle formed by the second direction D2 of the first liquid crystal unit 100-1 and the second direction D2 of the second liquid crystal unit 100-2 is 180°.

[0050] The first direction D1 and the second direction D2 of the third liquid crystal unit 100-3 are respectively the -x direction and the +y direction. In other words, the third liquid crystal unit 100-3 is arranged on the second liquid crystal unit 100-2 in such a way that the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the third liquid crystal unit 100-3 is 180°, and the angle formed by the second direction D2 of the first liquid crystal unit 100-1 and the second direction D2 of the third liquid crystal unit 100-3 is 0°.

[0051] The first direction D1 and the second direction D2 of the fourth liquid crystal unit 100-4 are respectively the +x direction and the -y direction. In other words, the fourth liquid crystal unit 100-4 is arranged on the third liquid crystal unit 100-3 in such a manner that the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the fourth liquid crystal unit 100-4 is 0°, and the angle formed by the second direction D2 of the first liquid crystal unit 100-1 and the second direction D2 of the fourth liquid crystal unit 100-4 is 180°.

[0052] In this way, in the optical element 10, moire fringes can be reduced by stacking a plurality of liquid crystal cells 100 having the same structure in different configuration directions. In addition, the optical element 10 can be manufactured using one type of liquid crystal cell 100, thereby reducing the manufacturing cost of the optical device 1. In addition, the optical element 10 may also include liquid crystal cells having the same configuration direction.

[0053] [2. Structure of Liquid Crystal Cell]

[0054] As described above, the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4 are liquid crystal cells 100 having the same structure. Therefore, the structure of the liquid crystal cell 100 is described below by taking the first liquid crystal cell 100-1 as an example.

[0055] Figure 3 1 is a schematic perspective view of a first liquid crystal unit 100 - 1 of an optical device 1 according to an embodiment of the present invention. Figure 4A as well as Figure 4B Each of them is a schematic cross-sectional view of a first liquid crystal unit 100 - 1 of an optical device 1 according to an embodiment of the present invention. Specifically, Figure 4A is Figure 3 A cross-sectional view of the first liquid crystal unit 100 - 1 in the zx plane cut along the line A1 - A2 , Figure 4B is Figure 3 A cross-sectional view of the first liquid crystal unit 100 - 1 in the yz plane cut along the line B1 - B2.

[0056] The first liquid crystal unit 100-1 includes a first substrate 110-1, a second substrate 110-2, a first transparent electrode 120-1, a second transparent electrode 120-2, a third transparent electrode 120-3, a fourth transparent electrode 120-4, a first alignment film 130-1, a second alignment film 130-2, a sealing material 140, and a liquid crystal layer 150. In addition, below, when the first substrate 110-1 and the second substrate 110-2 are not particularly distinguished, they are sometimes described as the substrate 110. Similarly, when the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4 are not particularly distinguished, they are sometimes described as the transparent electrode 120.

[0057] A first transparent electrode 120-1, a second transparent electrode 120-2, and a first alignment film 130-1 covering the first transparent electrode 120-1 and the second transparent electrode 120-2 are provided on the first substrate 110-1. In addition, a third transparent electrode 120-3, a fourth transparent electrode 120-4, and a second alignment film 130-2 covering the third transparent electrode 120-3 and the fourth transparent electrode 120-4 are provided on the second substrate 110-2. The first substrate 110-1 and the second substrate 110-2 are arranged so that the first transparent electrode 120-1 and the second transparent electrode 120-2 on the first substrate 110-1 are opposed to the third transparent electrode 120-3 and the fourth transparent electrode 120-4 on the second substrate 110-2. In addition, the first substrate 110-1 and the second substrate 110-2 are bonded via a sealing material 140 provided at the periphery of the first substrate 110-1 and the second substrate 110-2. In addition, liquid crystal is sealed in a space surrounded by the first substrate 110 - 1 (more specifically, the first alignment film 130 - 1 ), the second substrate 110 - 2 (more specifically, the second alignment film 130 - 2 ), and the sealant 140 , and a liquid crystal layer 150 is provided between the first substrate 110 - 1 and the second substrate 110 - 2 .

[0058] As the first substrate 110-1 and the second substrate, a light-transmitting rigid substrate such as a glass substrate, a quartz substrate, or a sapphire substrate is used respectively. In addition, as each of the first substrate 110-1 and the second substrate 110-2, a light-transmitting flexible substrate such as a polyimide resin substrate, an acrylic resin substrate, a silicone resin substrate, or a fluororesin substrate may be used.

[0059] The first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4 function as electrodes for forming an electric field in the liquid crystal layer 150. For example, transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO) are used as the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4. In addition, opaque metal materials may be used as the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4.

[0060] The details of the planar patterns of the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3 and the fourth transparent electrode 120-4 are described later. Figure 4A as well as Figure 4BAs shown, the first transparent electrode 120 - 1 and the second transparent electrode 120 - 2 extend substantially along the x-axis direction, and the third transparent electrode 120 - 3 and the fourth transparent electrode 120 - 4 extend substantially along the y-axis direction.

[0061] The liquid crystal layer 150 can bend the transmitted light or change the polarization state of the transmitted light according to the orientation state of the liquid crystal molecules. As the liquid crystal of the liquid crystal layer 150, nematic liquid crystal or the like is used. The liquid crystal described in this embodiment is a positive type, but a negative type can also be applied by changing the orientation direction of the liquid crystal molecules in a state where no voltage is applied to the transparent electrode 120. In addition, it is preferable that a chiral agent that imparts twist to the liquid crystal molecules is contained in the liquid crystal.

[0062] The first alignment film 130-1 and the second alignment film 130-2 respectively align the liquid crystal molecules in the liquid crystal layer 150 in a predetermined direction. As the first alignment film 130-1 and the second alignment film 130-2, polyimide resin or the like is used. In addition, the first alignment film 130-1 and the second alignment film 130-2 can be given alignment characteristics by an alignment treatment such as a rubbing method or a photo-alignment method. The rubbing method is a method of rubbing the surface of the alignment film in one direction. In addition, the photo-alignment method is a method of irradiating the alignment film with linearly polarized ultraviolet rays.

[0063] The first alignment film 130-1 is rubbed in the y-axis direction and has an alignment property that allows the long axes of the liquid crystal molecules on the first substrate 110-1 side of the liquid crystal layer 150 to be aligned in the y-axis direction. In addition, the second alignment film 130-2 is rubbed in the x-axis direction and has an alignment property that allows the long axes of the liquid crystal molecules on the second substrate 110-2 side of the liquid crystal layer 150 to be aligned in the x-axis direction.

[0064] In addition, in this embodiment, the case where the orientation direction (y-axis direction) of the first orientation film 130-1 is orthogonal to the orientation direction (x-axis direction) of the second orientation film 130-2 is described, but the angle formed by the orientation direction of the first orientation film 130-1 and the orientation direction of the second orientation film 130-2 is not limited to 90°. The angle formed by the orientation direction of the first orientation film 130-1 and the orientation direction of the second orientation film 130-2 may be an angle close to 90°, for example, 80° or more and less than 90°.

[0065] An adhesive material such as epoxy resin or acrylic resin is used as the sealing material 140. The adhesive material may be an ultraviolet curing type or a thermosetting type.

[0066] In the above, the structure of the first liquid crystal unit 100-1 is described, but in the optical element 10, four liquid crystal units having the same structure are stacked while changing the arrangement directions. Specifically, the second liquid crystal unit 100-2 is arranged on the first liquid crystal unit 100-1 in such a manner that the first substrate 110-1 of the second liquid crystal unit 100-2 is opposed to the second substrate 110-2 of the first liquid crystal unit 100-1. In addition, the third liquid crystal unit 100-3 is arranged on the second liquid crystal unit 100-2 in such a manner that the second substrate 110-2 of the third liquid crystal unit 100-3 is opposed to the second substrate of the second liquid crystal unit 100-2. In addition, the fourth liquid crystal unit 100-4 is arranged on the third liquid crystal unit 100-3 in such a manner that the second substrate of the fourth liquid crystal unit 100-4 is opposed to the first substrate 110-1 of the third liquid crystal unit.

[0067] [3. Characteristics of Liquid Crystal Cell]

[0068] Here, refer to Figure 5A as well as Figure 5B , the properties of light passing through the first liquid crystal unit 100 - 1 are described.

[0069] Figure 5A as well as Figure 5B 1 is a schematic cross-sectional view for explaining the properties of light passing through the first liquid crystal unit 100 - 1 of the optical device 1 according to one embodiment of the present invention. Specifically, Figure 5A 1 shows the first liquid crystal unit 100 - 1 in a state where no voltage is applied to the transparent electrode 120 . Figure 5B The first liquid crystal cell 100 - 1 is shown in a state where a voltage is applied to the transparent electrode 120 .

[0070] like Figure 5A As shown in FIG. 1 , when no voltage is applied to the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4, the liquid crystal molecules in the liquid crystal layer 150 are oriented in a manner of twisting 90° along the z-axis direction from the first substrate 110-1 toward the second substrate 110-2. Therefore, the polarization plane (the direction of the polarization axis or polarization component) of the light passing through the liquid crystal layer 150 is rotated 90° according to the orientation direction of the liquid crystal molecules. That is, the light passing through the liquid crystal layer 150 is optically rotated.

[0071] exist Figure 5BIn the embodiment, a voltage is applied in such a way that a potential difference is generated between two adjacent transparent electrodes 120. For example, a high voltage (H) is applied to the first transparent electrode 120-1 and the third transparent electrode 120-3, and a low voltage (L) is applied to the second transparent electrode 120-2 and the fourth transparent electrode 120-4. In addition, hereinafter, the electric field generated between two adjacent transparent electrodes 120 is sometimes referred to as a lateral electric field.

[0072] The liquid crystal molecules near the first substrate 110-1 side are oriented in a convex arc shape in the y-axis direction relative to the first substrate 110-1 by the lateral electric field between the first transparent electrode 120-1 and the second transparent electrode 120-2, thereby generating a refractive index distribution. In addition, the liquid crystal molecules near the second substrate 110-2 side are oriented in a convex arc shape in the x-axis direction relative to the second substrate 110-2 by the lateral electric field between the third transparent electrode 120-3 and the fourth transparent electrode 120-4, thereby generating a refractive index distribution. On the other hand, since the interval between the first substrate 110-1 and the second substrate 110-2, i.e., the cell gap d, is sufficiently larger than the distance between two adjacent transparent electrodes (e.g., 10μm≤d≤30μm), the orientation of the liquid crystal molecules near the center between the first substrate 110-1 and the second substrate 110-2 hardly changes.

[0073] The light emitted from the light source 20 includes a polarization component in the x-axis direction (hereinafter referred to as a “P polarization component”) and a polarization component in the y-axis direction (hereinafter referred to as an “S polarization component”). However, for convenience, the light emitted from the light source 20 is described below as a first polarized light 1000-1 having a P polarization component and a second polarized light 1000-2 having an S polarization component (refer to Figure 5B of (1)).

[0074] The P polarization component of the first polarized light 1000-1 incident on the liquid crystal cell 100 is different from the orientation direction of the liquid crystal molecules on the first substrate 110-1 side, so the first polarized light 1000-1 is not diffused (refer to Figure 5B (2)). When the first polarized light 1000-1 passes through the liquid crystal layer 150, the direction of its polarization component rotates by the angle (in this embodiment, 90°) formed by the orientation direction of the first orientation film 130-1 and the second orientation film 130-2 (this phenomenon is sometimes referred to as optical rotation), and the polarization component changes from the P polarization component to the S polarization component. Since the S polarization component of the first polarized light 1000-1 is different from the orientation direction of the liquid crystal molecules on the second substrate 110-2 side, the first polarized light 1000-1 does not diffuse (refer to Figure 5B (3)). In addition, the first polarized light 1000-1 emitted from the liquid crystal unit 100 has an S polarization component (refer to Figure 5B of (4)).

[0075] On the other hand, since the S polarization component of the second polarized light 1000-2 incident on the liquid crystal cell 100 is aligned in the same direction as the liquid crystal molecules on the first substrate 110-1 side, the second polarized light 1000-2 diffuses in the y-axis direction according to the refractive index distribution of the liquid crystal molecules (refer to Figure 5B (2)). The second polarized light 1000-2 undergoes optical rotation in the process of passing through the liquid crystal layer 150, and the polarization component changes from the S polarization component to the P polarization component. Since the P polarization component of the second polarized light 1000-2 is in the same orientation direction as the liquid crystal molecules on the second substrate 110-2 side, the second polarized light 1000-2 diffuses in the x-axis direction according to the refractive index distribution of the liquid crystal molecules (refer to Figure 5B (3)). In addition, the second polarized light 1000-2 emitted from the liquid crystal unit 100 has a P polarization component (refer to Figure 5B of (4)).

[0076] In the above, the characteristics of the first liquid crystal unit 100-1 are described. However, in the optical element 10, four liquid crystal units having the same structure are stacked while changing the arrangement directions. The diffusion characteristics of the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 with respect to the P polarization component and the S polarization component of the light emitted from the light source 20 are shown in Table 1. In addition, Table 1 shows the case where a voltage is applied to all transparent electrodes 120 (that is, a potential difference is generated between two adjacent transparent electrodes 120 on the substrate 110).

[0077]

[0078] [5. Planar pattern of transparent electrode]

[0079] Fig. 6A as well as Figure 6B Each of them is a schematic top view showing a planar pattern of a transparent electrode 120 of a first liquid crystal unit 100 - 1 of an optical device 1 according to an embodiment of the present invention. Specifically, Fig. 6A represents the planar pattern of the first transparent electrode 120 - 1 and the second transparent electrode 120 - 2 on the first substrate 110 - 1 , Figure 6B 1 and 2 show the planar patterns of the third transparent electrode 120 - 3 and the fourth transparent electrode 120 - 4 on the second substrate 110 - 2 .

[0080] like Fig. 6AAs shown, a plurality of first transparent electrodes 120-1, a plurality of second transparent electrodes 120-2, wiring WL11, wiring WL12, a first connection terminal T11, and a second connection terminal T12 are provided on the first substrate 110-1. The plurality of first transparent electrodes 120-1 are electrically connected to the first connection terminal T11 via the wiring WL11, respectively. In addition, the plurality of second transparent electrodes 120-2 are electrically connected to the second connection terminal T12 via the wiring WL12, respectively. Furthermore, a third connection terminal T13, a fourth connection terminal T14, wiring WL13, wiring WL14, a first connection pad PD11, and a second connection pad PD12 are provided on the first substrate 110-1. The first connection pad PD11 is electrically connected to the third connection terminal T13 via the wiring WL13. The second connection pad PD12 is electrically connected to the fourth connection terminal T14 via the wiring WL14.

[0081] A flexible printed circuit board is connected to the first connection terminal T11 , the second connection terminal T12 , the third connection terminal T13 , and the fourth connection terminal T14 , and a voltage is supplied to the flexible printed circuit board as a control signal for controlling the first liquid crystal unit 100 - 1 .

[0082] As the wiring WL11, the wiring WL12, the wiring WL13, the wiring WL14, the first connection pad PD11, the second connection pad PD12, the first connection terminal T11, the second connection terminal T12, the third connection terminal T13 and the fourth connection terminal T14, a transparent conductive material or a metal material may be used.

[0083] The plurality of first transparent electrodes 120-1 include a first straight portion LP11, a second straight portion LP12, and a first curved portion CP11, respectively. The first straight portion LP11 and the second straight portion LP12 are not parallel, but are connected at a predetermined angle at the first curved portion CP11. Similarly, the plurality of second transparent electrodes 120-2 also include a first straight portion LP11, a second straight portion LP12, and a first curved portion CP11, respectively. However, in the first transparent electrode 120-1, the first straight portion LP11 is connected to the wiring WL11, and the second straight portion LP12 has an end portion, whereas in the second transparent electrode 120-2, the second straight portion LP12 is connected to the wiring WL12, and the first straight portion LP11 has an end portion. In this regard, the structures of the first transparent electrode 120-1 and the second transparent electrode 120-2 are different.

[0084] like Figure 6BAs shown, a plurality of third transparent electrodes 120-3, a plurality of fourth transparent electrodes 120-4, wiring WL23, wiring WL24, a third connection pad PD23 and a fourth connection pad PD24 are included on the second substrate 110-2. The plurality of third transparent electrodes 120-3 are electrically connected to the third connection pad PD23 via the wiring WL23, respectively. In addition, the plurality of fourth transparent electrodes 120-4 are electrically connected to the fourth connection pad PD24 via the wiring WL24, respectively. The third connection pad PD23 and the fourth connection pad PD24 are electrically connected to the first connection pad PD11 and the second connection pad PD12, respectively, through a conductive material. Therefore, the plurality of third transparent electrodes 120-3 are electrically connected to the third connection terminal T13, respectively, and the plurality of fourth transparent electrodes 120-4 are electrically connected to the fourth connection terminal T14, respectively.

[0085] The plurality of third transparent electrodes 120-3 respectively include a third straight portion LP23, a fourth straight portion LP24, and a second curved portion CP22. The third straight portion LP23 is not parallel to the fourth straight portion LP24, but is connected at a predetermined angle at the second curved portion CP22. Similarly, the plurality of fourth transparent electrodes 120-4 also respectively include a third straight portion LP23, a fourth straight portion LP24, and a second curved portion CP22. However, in the third transparent electrode 120-3, the third straight portion LP23 is connected to the wiring WL23, and the fourth straight portion LP24 has an end portion, whereas in the fourth transparent electrode 120-4, the fourth straight portion LP24 is connected to the wiring WL24, and the third straight portion LP23 has an end portion. In this regard, the structures of the third transparent electrode 120-3 and the fourth transparent electrode 120-4 are different.

[0086] Figure 7 1 is a top view showing a planar pattern of a transparent electrode 120 of a first liquid crystal unit 100-1 of an optical device 1 according to an embodiment of the present invention. When viewed from above, the first transparent electrode 120-1, the second transparent electrode 120-2, the third transparent electrode 120-3, and the fourth transparent electrode 120-4 each have a く-shaped shape. The third transparent electrode 120-3 overlaps with the first transparent electrode 120-1 and the second transparent electrode 120-2. Similarly, the fourth transparent electrode 120-4 also overlaps with the first transparent electrode 120-1 and the second transparent electrode 120-2.

[0087] Here, refer to Figure 8A to Figure 8D , the extending directions of the first straight line portion LP11 , the second straight line portion LP12 , the third straight line portion LP23 , and the fourth straight line portion LP24 of the transparent electrode 120 are described.

[0088] Fig. 8A1 is a schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the first liquid crystal unit 100 - 1 of the optical device 1 according to one embodiment of the present invention. Fig. 8A , the extending directions of the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23 and the fourth straight line portion LP24 of the first liquid crystal unit 100-1 in the xy coordinates with the first curved portion CP11 and the second curved portion CP22 as the origins are shown. In this specification, for the sake of convenience, the center line in the longitudinal direction of the straight line portion is defined as the extending direction.

[0089] In the first liquid crystal unit 100-1, the first straight line portion LP11 extends at an angle α° (0<α<90) relative to the x-axis direction. The second straight line portion LP12 extends at an angle β° (0<β<90 and β≠α) relative to the x-axis direction. The third straight line portion LP23 extends at an angle (90+α)° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle (90+β)° relative to the x-axis direction.

[0090] Here, if we divide it into the first quadrant, the second quadrant, the third quadrant and the fourth quadrant Fig. 8A According to the xy coordinates shown in FIG. 1 , the second straight line portion LP12, the third straight line portion LP23, the first straight line portion LP11, and the fourth straight line portion LP24 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when the first liquid crystal unit 100-1 is viewed from above, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 belong to different quadrants.

[0091] Figure 8B 1 is a schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the second liquid crystal unit 100 - 2 of the optical device 1 according to one embodiment of the present invention. Figure 8B , a first straight line portion LP11, a second straight line portion LP12, a third straight line portion LP23, and a fourth straight line portion LP24 in the second liquid crystal unit 100-2 are shown with the first curved portion CP11 and the second curved portion CP22 as the origins of the x-axis and the y-axis.

[0092] In the second liquid crystal unit 100-2, the first straight line portion LP11 extends at an angle α° relative to the x-axis direction. The second straight line portion LP12 extends at an angle β° relative to the x-axis direction. The third straight line portion LP23 extends at an angle (90+α)° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle (90+β)° relative to the x-axis direction. In the second liquid crystal unit 100-2, the first straight line portion LP11, the fourth straight line portion LP24, the second straight line portion LP12, and the third straight line portion LP23 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when looking down at the second liquid crystal unit 100-2, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 also belong to different quadrants.

[0093] Figure 8C Schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the third liquid crystal unit 100 - 3 of the optical device 1 according to one embodiment of the present invention. Figure 8C , a first straight line portion LP11, a second straight line portion LP12, a third straight line portion LP23 and a fourth straight line portion LP24 in the third liquid crystal unit 100-3 are shown with the first curved portion CP11 and the second curved portion CP22 as the origins of the x-axis and the y-axis.

[0094] In the third liquid crystal unit 100-3, the first straight line portion LP11 extends at an angle of -α° relative to the x-axis direction. The second straight line portion LP12 extends at an angle of -β° relative to the x-axis direction. The third straight line portion LP23 extends at an angle of (90-α)° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle of (90-β)° relative to the x-axis direction. In the third liquid crystal unit 100-3, the third straight line portion LP23, the second straight line portion LP12, the fourth straight line portion LP24, and the first straight line portion LP11 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when the third liquid crystal unit 100-3 is viewed from above, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 also belong to different quadrants.

[0095] Fig.8D Schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the fourth liquid crystal unit 100 - 4 of the optical device 1 according to one embodiment of the present invention. Fig.8D , a first straight line portion LP11, a second straight line portion LP12, a third straight line portion LP23, and a fourth straight line portion LP24 in the fourth liquid crystal unit 100-4 are shown with the first curved portion CP11 and the second curved portion CP22 as the origins of the x-axis and the y-axis.

[0096] In the fourth liquid crystal unit 100-4, the first straight line portion LP11 extends at an angle of -α° relative to the x-axis direction. The second straight line portion LP12 extends at an angle of -β° relative to the x-axis direction. The third straight line portion LP23 extends at an angle of (90-α)° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle of (90-β)° relative to the x-axis direction. In the fourth liquid crystal unit 100-4, the fourth straight line portion LP24, the first straight line portion LP11, the third straight line portion LP23, and the second straight line portion LP12 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when the fourth liquid crystal unit 100-4 is viewed from above, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 also belong to different quadrants.

[0097] Table 2 shows the straight line portions belonging to each quadrant in the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4. In addition, Table 3 shows the angles formed by the straight line portions belonging to each quadrant in the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4 with respect to the x-axis direction.

[0098]

[0099]

[0100] As can be seen from Tables 2 and 3, in the optical element 10, even if the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 are stacked, the straight line portions belong to each quadrant, and the straight line portions in each quadrant overlap at staggered angles. Therefore, in the optical element 10, moire fringes are reduced. In addition, the angles α° and β° are preferably greater than 0° and less than 45°, more preferably greater than 0° and less than 30°, and particularly preferably greater than 0° and less than 10°.

[0101] In the above, the angle of the extending direction of the transparent electrode 120 is described with the bent portion as the center, but the angle may be specified with the base of the transparent electrode 120 (i.e., the connection portion between the transparent electrode 120 and the wiring) as the center. In this case, the two straight line portions included in one transparent electrode 120 can be bent from the x-axis direction or the y-axis direction to the same direction (positive direction or negative direction) at a specified angle.

[0102] Here, refer to Fig.9A as well as Fig. 9B , the position of the bending portion is described.

[0103] Fig.9A as well as Fig. 9B 1 is a schematic top view showing the overlapping state of transparent electrodes 120 extending in the x-axis direction and the y-axis direction in the optical device 1 according to one embodiment of the present invention. As described above, the straight portion of the transparent electrode 120 extends at a predetermined angle relative to the x-axis direction, but Fig.9A In the description, it is assumed that the first transparent electrode 120-1 and the second transparent electrode 120-2 extend substantially along the x-axis direction. Fig. 9B In the description, it is assumed that the third transparent electrode 120 - 3 and the fourth transparent electrode 120 - 4 extend substantially in the y-axis direction.

[0104] like Fig.9A As shown, the first straight line portion LP11_1 and the second straight line portion LP12_1 of the first liquid crystal cell 100-1, the first straight line portion LP11_2 and the second straight line portion LP12_2 of the second liquid crystal cell 100-2, the first straight line portion LP11_3 and the second straight line portion LP12_3 of the third liquid crystal cell 100-3, and the first straight line portion LP11_4 and the second straight line portion LP12_4 of the fourth liquid crystal cell 100-4 do not completely overlap each other when viewed in the length direction. However, the first curved portion CP11 included in the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4 is placed on a straight line extending in the y-axis direction when viewed from above.

[0105] like Fig. 9B As shown, the third straight line portion LP23_1 and the fourth straight line portion LP24_1 of the first liquid crystal unit 100-1, the third straight line portion LP23_2 and the fourth straight line portion LP24_2 of the second liquid crystal unit 100-2, the third straight line portion LP23_3 and the fourth straight line portion LP24_3 of the third liquid crystal unit 100-3, and the third straight line portion LP23_4 and the fourth straight line portion LP24_4 of the fourth liquid crystal unit 100-4 do not completely overlap each other when viewed in the length direction. However, the second curved portion CP22 included in the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 is placed on a straight line extending along the x-axis direction when viewed from above.

[0106] [6. Other structures of optical elements]

[0107] In the liquid crystal cell 100 including the transparent electrode 120 having the above-described planar pattern, an optical element 10A different from the optical element 10 may be manufactured using a plurality of liquid crystal cells 100 having the same structure.

[0108] Fig.10 1 is a schematic exploded perspective view of an optical element 10A of an optical device 1 according to an embodiment of the present invention. The optical element 10A is different from the optical element 10 in that the third liquid crystal cell 100 - 3 and the fourth liquid crystal cell 100 - 4 are arranged in different directions.

[0109] In the optical element 10A, the first direction D1 and the second direction D2 of the third liquid crystal unit 100-3 are respectively the +y direction and the -x direction. In other words, the third liquid crystal unit 100-3 is arranged on the second liquid crystal unit 100-2 in such a manner that the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the third liquid crystal unit 100-3 is 90°, and the angle formed by the second direction D2 of the first liquid crystal unit 100-1 and the second direction D2 of the third liquid crystal unit 100-3 is 90°. The first direction D1 and the second direction D2 of the fourth liquid crystal unit 100-4 are respectively the -y direction and the +x direction. In other words, the fourth liquid crystal unit 100-4 is configured on the third liquid crystal unit 100-3 in such a way that the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the fourth liquid crystal unit 100-4 is 90°, and the angle formed by the first direction D1 of the first liquid crystal unit 100-1 and the first direction D1 of the fourth liquid crystal unit 100-4 is 90°.

[0110] The diffusion characteristics of the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, and the fourth liquid crystal unit 100-4 in the optical element 10A are shown in Table 4. In addition, Table 4 shows the case where a voltage is applied to all transparent electrodes 120 (i.e., a potential difference is generated between two adjacent transparent electrodes 120 on the substrate 110).

[0111]

[0112] Fig.11A Schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the third liquid crystal unit 100 - 3 of the optical element 10A included in the optical device 1 according to one embodiment of the present invention. Fig.11A : shows the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23 and the fourth straight line portion LP24 of the third liquid crystal unit 100-3 of the optical element 10A in the xy coordinates with the first curved portion CP11 and the second curved portion CP22 as the origin.

[0113] In the third liquid crystal unit 100-3 of the optical element 10A, the first straight line portion LP11 extends at an angle of (90-α)° relative to the x-axis direction. The second straight line portion LP12 extends at an angle of (90-β)° relative to the x-axis direction. The third straight line portion LP23 extends at an angle of -α° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle of -β° relative to the x-axis direction. In the third liquid crystal unit 100-3 of the optical element 10A, the first straight line portion LP11, the third straight line portion LP23, the second straight line portion LP12, and the fourth straight line portion LP24 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when looking down at the third liquid crystal unit 100-3 of the optical element 10A, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 belong to different quadrants.

[0114] Fig. 11B Schematic diagram for explaining the angle of the extending direction of the transparent electrode 120 of the fourth liquid crystal unit 100 - 4 of the optical element 10A included in the optical device 1 according to one embodiment of the present invention. Fig. 11B : shows the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23 and the fourth straight line portion LP24 of the fourth liquid crystal unit 100-4 of the optical element 10A in the xy coordinates with the first curved portion CP11 and the second curved portion CP22 as the origin.

[0115] In the fourth liquid crystal unit 100-4 of the optical element 10A, the first straight line portion LP11 extends at an angle of (90-α)° relative to the x-axis direction. The second straight line portion LP12 extends at an angle of (90-β)° relative to the x-axis direction. The third straight line portion LP23 extends at an angle of -α° relative to the x-axis direction. The fourth straight line portion LP24 extends at an angle of -β° relative to the x-axis direction. In the fourth liquid crystal unit 100-4 of the optical element 10A, the second straight line portion LP12, the fourth straight line portion LP24, the first straight line portion LP11, and the third straight line portion LP23 belong to the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, respectively. That is, when looking down at the fourth liquid crystal unit 100-4 of the optical element 10A, the first straight line portion LP11, the second straight line portion LP12, the third straight line portion LP23, and the fourth straight line portion LP24 also belong to different quadrants.

[0116] Table 5 shows the straight line portions belonging to each quadrant in the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4. Table 6 shows the angles formed by the straight line portions belonging to each quadrant in the first liquid crystal cell 100-1, the second liquid crystal cell 100-2, the third liquid crystal cell 100-3, and the fourth liquid crystal cell 100-4 with respect to the x-axis direction.

[0117]

[0118]

[0119] It can be seen from Tables 5 and 6 that, similar to the optical element 10, in the optical element 10A, even if the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3 and the fourth liquid crystal unit 100-4 are stacked, the straight line portions belong to each quadrant, and the straight line portions in each quadrant overlap with staggered angles.

[0120] As described above, the optical element 10 of the optical device 1 includes a plurality of liquid crystal cells 100 having the same structure, and moire fringes can be reduced by mutually changing the arrangement directions of the liquid crystal cells 100. In addition, in the case of the liquid crystal cells 100, it is also possible to manufacture an optical element 10A different from the optical element 10, and the versatility of the liquid crystal cells 100 is high, and the manufacturing cost of the optical device 1 can be suppressed.

[0121] <Second Embodiment>

[0122] Reference Fig.12 , an optical device according to an embodiment of the present invention will be described. In addition, the description of the same structure as the optical device 1 may be omitted below.

[0123] Fig.12 This is a schematic plan view showing a plan pattern of a first transparent electrode 120B- 1 and a second transparent electrode 120B- 2 of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0124] like Fig.12 As shown, the first transparent electrode 120B-1 and the second transparent electrode 120B-2 include a first straight portion LP11B, a second straight portion LP12B and a first curved portion CP11B, respectively. In addition, the first straight portion LP11B and the second straight portion LP12B intersect and connect at the first curved portion CP11B. The widths of the first straight portion LP11B and the second straight portion LP12B are not uniform, and both increase toward the first curved portion CP11B. In addition, Fig.12In the embodiment, the widths of the first straight portion LP11B and the second straight portion LP12B gradually increase toward the first curved portion CP11B, but may also increase in a step-like manner.

[0125] In the optical device according to the present embodiment, the width of the transparent electrode 120B and the inter-electrode distance between the adjacent first transparent electrode 120B- 1 and the second transparent electrode 120B- 2 are changed, so that the moire fringe can be further reduced.

[0126] <Third Embodiment>

[0127] Reference Fig.13 , an optical device according to an embodiment of the present invention will be described. In addition, the description of the same structure as the optical device 1 may be omitted below.

[0128] Fig.13 This is a schematic plan view showing a plan pattern of a first transparent electrode 120C- 1 and a second transparent electrode 120C- 2 of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0129] like Fig.13 As shown, the first transparent electrode 120C-1 and the second transparent electrode 120C-2 include a first straight portion LP11C, a second straight portion LP12C and a first curved portion CP11C. In addition, the first straight portion LP11C and the second straight portion LP12C intersect and connect at the first curved portion CP11C. The widths of the first straight portion LP11C and the second straight portion LP12C are not uniform, and both become smaller toward the first curved portion CP11C. In addition, Fig.13 In the embodiment, the widths of the first straight portion LP11B and the second straight portion LP12B gradually decrease toward the first curved portion CP11C, but may also decrease in a step-like manner.

[0130] In the optical device according to the present embodiment, the width of the transparent electrode 120C and the inter-electrode distance between the adjacent first transparent electrode 120C- 1 and the second transparent electrode 120C- 2 are changed, so that the moire fringe can be further reduced.

[0131] <Fourth Embodiment>

[0132] Reference Fig.14 , an optical device according to an embodiment of the present invention will be described. In addition, the description of the same structure as the optical device 1 may be omitted below.

[0133] Fig.14It is a schematic plan view showing a plan pattern of a first transparent electrode 120D- 1 and a second transparent electrode 120D- 2 of a first liquid crystal cell of an optical device according to an embodiment of the present invention.

[0134] like Fig.14 As shown, the first transparent electrode 120C-1 and the second transparent electrode 120C-2 each include a plurality of first curved portions CP11. The plurality of first curved portions CP11 may be arranged regularly or randomly. However, the first curved portion CP11 located in the central portion is regularly arranged in a straight line extending along the y-axis direction.

[0135] In the optical device according to the present embodiment, the overlap of the transparent electrodes 120D of the plurality of liquid crystal cells in the stacking direction is reduced, and thus the moire fringes can be further reduced.

[0136] As embodiments of the present invention, the above embodiments can be appropriately combined to implement as long as they are not contradictory. In addition, based on each embodiment, those skilled in the art appropriately add, delete or design changes the constituent elements, or add, omit or change the conditions of the process, and as long as they have the gist of the present invention, they are also included in the scope of the present invention.

[0137] Even if there are other effects different from the effects brought about by the forms of the above-mentioned embodiments, the effects that are clear based on the description of this specification or the effects that can be easily predicted by those skilled in the art can of course be understood as the effects brought about by the present invention.

[0138] Description of Reference Numerals

[0139] 1: optical device; 10, 10A: optical element; 20: light source; 100: liquid crystal unit; 100-1: first liquid crystal unit; 100-2: second liquid crystal unit; 100-3: third liquid crystal unit; 100-4: fourth liquid crystal unit; 110: substrate; 110-1: first substrate; 110-2: second substrate; 120, 120B, 120C, 120D: transparent electrodes; 120-1, 120B-1, 120C-1, 120D-1: first transparent electrode; 120-2, 120B-2, 120C-2, 120D: second transparent electrode; 120-3: third transparent electrode; 120-4: fourth transparent electrode; 130-1: first alignment film; 130-2: second alignment film; 140: sealing material; 150: liquid crystal layer; 200: optical elastic resin layer ; 210: flexible printed circuit substrate; 1000-1: first polarized light; 1000-2: second polarized light; CP11, CP11B, CP11C: first bending portion; CP22: second bending portion; D1: first direction; D2: second direction; LP11, LP11B, LP11C: first straight portion; LP12, LP12B, LP12C: second straight portion; LP23: third straight portion; LP24: fourth straight portion; PD11: first connecting pad; PD12: second connecting pad; PD23: third connecting pad; PD24: fourth connecting pad; T11: first connecting terminal; T12: second connecting terminal; T13: third connecting terminal; T14: fourth connecting terminal; WL11, WL12, WL13, WL14, WL23, WL24: wiring.

Claims

1. An optical device, comprising: light source; as well as The optical element includes a plurality of stacked liquid crystal cells, and controls the light distribution of the light emitted from the light source. The plurality of liquid crystal units respectively include: A first substrate, alternately provided with first electrodes and second electrodes; A second substrate having third electrodes and fourth electrodes alternately arranged thereon; and A liquid crystal layer between the first substrate and the second substrate, The first electrode and the second electrode respectively include: a first straight portion extending at an angle α° relative to the first direction, wherein 0<α<90; and The second straight line portion extends at an angle β° relative to the first direction, wherein 0<β<90 and β≠α, The third electrode and the fourth electrode respectively include: a third straight portion extending at an angle of (90+α)° relative to the first direction; and a fourth straight line portion extending at an angle of (90+β)° relative to the first direction, The plurality of liquid crystal units include: a first liquid crystal unit, which is disposed closest to the light source; and a second liquid crystal unit, which is stacked on the first liquid crystal unit. The first substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, The second liquid crystal cell is arranged to overlap with the first liquid crystal cell such that an angle formed by the first direction of the first liquid crystal cell and the first direction of the second liquid crystal cell is 180°.

2. The optical device according to claim 1, wherein: In a plan view, a first curved portion connecting the first straight portion and the second straight portion overlaps with a second curved portion connecting the third straight portion and the fourth straight portion.

3. The optical device according to claim 2, wherein: The widths of the first straight portion and the second straight portion increase toward the first curved portion. The widths of the third straight portion and the fourth straight portion increase toward the second curved portion.

4. The optical device according to claim 2, wherein: The widths of the first straight portion and the second straight portion decrease toward the first curved portion. The widths of the third straight portion and the fourth straight portion decrease toward the second curved portion.

5. The optical device according to claim 1, wherein: The first electrode and the second electrode each include a plurality of first curved portions connecting the first straight portion and the second straight portion. The third electrode and the fourth electrode respectively include a plurality of second bending portions connecting the third straight portion and the fourth straight portion, One of the plurality of first bent portions overlaps with one of the plurality of second bent portions.

6. The optical device according to claim 1, wherein: The plurality of liquid crystal units further include: a third liquid crystal unit stacked on the second liquid crystal unit on a side opposite to the first liquid crystal unit; and a fourth liquid crystal unit stacked on the third liquid crystal unit on a side opposite to the second liquid crystal unit. The second substrate of the third liquid crystal unit is opposite to the second substrate of the second liquid crystal unit, The second substrate of the fourth liquid crystal unit is opposite to the first substrate of the third liquid crystal unit, The third liquid crystal unit is arranged to overlap with the first liquid crystal unit and the second liquid crystal unit in such a manner that the angle formed by the first direction of the first liquid crystal unit and the first direction of the third liquid crystal unit is 180°. The fourth liquid crystal cell is arranged to overlap with the first to third liquid crystal cells such that an angle formed between the first direction of the first liquid crystal cell and the first direction of the fourth liquid crystal cell is 0°.

7. The optical device according to claim 1, wherein: The plurality of liquid crystal units further include: a third liquid crystal unit stacked on the second liquid crystal unit on a side opposite to the first liquid crystal unit; and a fourth liquid crystal unit stacked on the third liquid crystal unit on a side opposite to the second liquid crystal unit. The second substrate of the third liquid crystal unit is opposite to the second substrate of the second liquid crystal unit, The second substrate of the fourth liquid crystal unit is opposite to the first substrate of the third liquid crystal unit, The third liquid crystal unit is arranged to overlap with the first liquid crystal unit and the second liquid crystal unit in such a manner that the angle formed by the first direction of the first liquid crystal unit and the first direction of the third liquid crystal unit is 90°. The fourth liquid crystal cell is arranged to overlap with the first to third liquid crystal cells such that the angle formed by the first direction of the first liquid crystal cell and the first direction of the fourth liquid crystal cell is 90°.

Images