Optical element and lighting device

Abstract

An optical element in which at least two or more liquid crystal cells are stacked, each of the at least two or more liquid crystal cells including: a first substrate provided with a first connection pad electrically connected to a first electrode and a second connection pad electrically connected to a second electrode; and a second substrate provided with a third connection pad electrically connected to the third electrode and a fourth connection pad electrically connected to the fourth electrode, the first connection pads, the second connection pads, the third connection pads, and the fourth connection pads of the at least two or more liquid crystal cells being electrically connected to each other via inter-cell conduction electrodes, respectively.

Description

Technical Field

[0001] One embodiment of the present invention relates to an optical element that uses liquid crystal to control the light distribution of light emitted from a light source. Another embodiment of the present invention relates to a lighting device including the optical element. Background Art

[0002] Conventionally, there is known an optical element that uses a change in the refractive index of liquid crystal by adjusting a potential applied to liquid crystal, namely a so-called liquid crystal lens. In addition, development of a lighting device using a light source and a liquid crystal lens is progressing (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-117344 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] Generally, in an optical element including a plurality of liquid crystal units, FPCs are connected to the plurality of liquid crystal units, respectively. That is, a plurality of FPCs are generally used to drive the optical element. However, such an optical element has a large number of wirings, which complicates the mounting process and increases the manufacturing cost.

[0008] In view of the above problems, one object of one embodiment of the present invention is to provide an optical element having electrical connections capable of simultaneously driving a plurality of liquid crystal cells by inputting one signal. In addition, one embodiment of the present invention relates to a lighting device including the above optical element.

[0009] Solutions for solving technical problems

[0010] An optical element involved in one embodiment of the present invention is stacked in sequence with a first liquid crystal unit, a second liquid crystal unit, a third liquid crystal unit and a fourth liquid crystal unit, and the first liquid crystal unit, the second liquid crystal unit, the third liquid crystal unit and the fourth liquid crystal unit each include: a first substrate, provided with a first electrode, a second electrode, a first connection pad electrically connected to the first electrode, and a second connection pad electrically connected to the second electrode; a second substrate, provided with a third electrode, a fourth electrode, a third connection pad electrically connected to the third electrode, and a fourth connection pad electrically connected to the fourth electrode; and a liquid crystal layer between the first substrate and the second substrate, the second substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, the first substrate of the third liquid crystal unit is opposite to the first substrate of the second liquid crystal unit, the second substrate of the fourth liquid crystal unit is opposite to the second substrate of the third liquid crystal unit, and the first connection pad of the first liquid crystal unit is connected to the third liquid crystal unit via a first inter-unit conductive electrode. The first connecting pad of the unit is electrically connected, the second connecting pad of the first liquid crystal unit is electrically connected to the second connecting pad of the third liquid crystal unit via the second inter-unit conducting electrode, the third connecting pad of the first liquid crystal unit is electrically connected to the third connecting pad of the third liquid crystal unit via the third inter-unit conducting electrode, the fourth connecting pad of the first liquid crystal unit is electrically connected to the fourth connecting pad of the third liquid crystal unit via the fourth inter-unit conducting electrode, the first connecting pad of the second liquid crystal unit is electrically connected to the first connecting pad of the fourth liquid crystal unit via the fifth inter-unit conducting electrode, the second connecting pad of the second liquid crystal unit is electrically connected to the second connecting pad of the fourth liquid crystal unit via the sixth inter-unit conducting electrode, the third connecting pad of the second liquid crystal unit is electrically connected to the third connecting pad of the fourth liquid crystal unit via the seventh inter-unit conducting electrode, and the fourth connecting pad of the second liquid crystal unit is electrically connected to the fourth connecting pad of the fourth liquid crystal unit via the eighth inter-unit conducting electrode.

[0011] An optical element involved in one embodiment of the present invention is stacked in sequence with a first liquid crystal unit, a second liquid crystal unit, a third liquid crystal unit and a fourth liquid crystal unit, and the first liquid crystal unit, the second liquid crystal unit, the third liquid crystal unit and the fourth liquid crystal unit each include: a first substrate, provided with a first electrode, a second electrode, a first connection pad electrically connected to the first electrode, and a second connection pad electrically connected to the second electrode; a second substrate, provided with a third electrode, a fourth electrode, a third connection pad electrically connected to the third electrode, and a fourth connection pad electrically connected to the fourth electrode; and a liquid crystal layer between the first substrate and the second substrate, the second substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, the first substrate of the third liquid crystal unit is opposite to the first substrate of the second liquid crystal unit, the second substrate of the fourth liquid crystal unit is opposite to the second substrate of the third liquid crystal unit, and the third connection pad of the second liquid crystal unit is connected to the third liquid crystal unit via the first inter-unit conductive electrode. The first connecting pad of the unit is electrically connected, the fourth connecting pad of the second liquid crystal unit is electrically connected to the second connecting pad of the third liquid crystal unit via the second inter-unit conducting electrode, the first connecting pad of the second liquid crystal unit is electrically connected to the third connecting pad of the third liquid crystal unit via the third inter-unit conducting electrode, the second connecting pad of the second liquid crystal unit is electrically connected to the fourth connecting pad of the third liquid crystal unit via the fourth inter-unit conducting electrode, the second connecting pad of the first liquid crystal unit is electrically connected to the first connecting pad of the fourth liquid crystal unit via the fifth inter-unit conducting electrode, the first connecting pad of the first liquid crystal unit is electrically connected to the second connecting pad of the fourth liquid crystal unit via the sixth inter-unit conducting electrode, the fourth connecting pad of the first liquid crystal unit is electrically connected to the third connecting pad of the fourth liquid crystal unit via the seventh inter-unit conducting electrode, and the third connecting pad of the first liquid crystal unit is electrically connected to the fourth connecting pad of the fourth liquid crystal unit via the eighth inter-unit conducting electrode.

[0012] An illumination device according to one embodiment of the present invention includes the optical element and a light source disposed adjacent to the first liquid crystal unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic perspective view showing the structure of the lighting device in the first embodiment.

[0014] Figure 2 It is a schematic exploded perspective view showing the structure of the optical element in the first embodiment.

[0015] Figure 3This is a schematic perspective view showing the structure of a liquid crystal cell included in the optical element according to the first embodiment.

[0016] Figure 4A This is a schematic cross-sectional view showing the structure of a liquid crystal cell included in the optical element according to the first embodiment.

[0017] Figure 4B This is a schematic cross-sectional view showing the structure of a liquid crystal cell included in the optical element according to the first embodiment.

[0018] Figure 5A is a schematic plan view illustrating an electrode pattern of a liquid crystal cell included in the optical element in the first embodiment.

[0019] Figure 5B is a schematic plan view illustrating an electrode pattern of a liquid crystal cell included in the optical element in the first embodiment.

[0020] Fig. 6A It is a schematic diagram for explaining the optical characteristics of the liquid crystal cell in the first embodiment.

[0021] Figure 6B It is a schematic diagram for explaining the optical characteristics of the liquid crystal cell in the first embodiment.

[0022] Fig. 7A It is a plan view (top view) for explaining the structure of electrical connection of the optical element in the first embodiment.

[0023] Figure 7B It is a plan view (bottom view) for explaining the structure of electrical connection of the optical element in the first embodiment.

[0024] Figure 7C This is a plan view (front view) illustrating the structure of electrical connection of the optical element in the first embodiment.

[0025] Fig.7D It is a plan view (right side view) for explaining the structure of electrical connection of the optical element in the first embodiment.

[0026] Fig. 7E It is a plan view (left side view) for explaining the structure of electrical connection of the optical element in the first embodiment.

[0027] Figure 7F It is a plan view (rear view) for explaining the structure of electrical connection of the optical element in the first embodiment.

[0028] Figure 7G This is a schematic perspective view for explaining the structure of electrical connection of the optical element in the first embodiment.

[0029] Figure 81 is a timing chart showing signals input to the optical element in order to control the linear light distribution in the x-axis direction in the first embodiment.

[0030] Fig. 9 1 is a timing chart showing signals input to the optical element in order to control the linear light distribution in the y-axis direction in the first embodiment.

[0031] Fig.10 1 is a timing chart showing signals input to the optical element in order to control the light distribution having a circular shape in the first embodiment.

[0032] Fig.11 1 is a timing chart showing signals input to the optical element in order to control the light distribution having an elliptical shape in the first embodiment.

[0033] Fig.12 1 is a timing chart showing signals input to the optical element in order to control the light distribution having a cross shape in the first embodiment.

[0034] Fig.13 1 is another timing chart showing signals input to the optical element in order to control the light distribution having a cross shape in the first embodiment.

[0035] Fig.14 It is a schematic perspective view showing the structure of the lighting device in the second embodiment.

[0036] Fig.15 It is a schematic plan view (top view) showing the structure of the optical element in the second embodiment.

[0037] Fig.16 It is a schematic perspective view showing the structure of the lighting device in the third embodiment.

[0038] Fig.17A It is a schematic plan view (top view) showing the structure of the optical element in the third embodiment.

[0039] Fig. 17B It is a schematic plan view (bottom view) showing the structure of the optical element in the third embodiment.

[0040] Fig. 17C It is a schematic plan view (front view) showing the structure of the optical element in the third embodiment.

[0041] Fig.17D It is a schematic plan view (right side view) showing the structure of the optical element in the third embodiment.

[0042] Fig.17E It is a schematic plan view (left side view) showing the structure of the optical element in the third embodiment.

[0043] Fig.17F It is a schematic plan view (rear view) showing the structure of the optical element in the third embodiment.

[0044] Fig.18 It is a schematic perspective view showing the structure of a lighting device in a fourth embodiment.

[0045] Fig.19 It is a schematic exploded perspective view showing the structure of the optical element in the fourth embodiment.

[0046] Fig. 20A It is a schematic plan view (top view) showing the structure of the optical element in the fourth embodiment.

[0047] Fig. 20B It is a schematic plan view (bottom view) showing the structure of the optical element in the fourth embodiment.

[0048] Fig. 20C It is a schematic plan view (front view) showing the structure of an optical element in the fourth embodiment.

[0049] Fig.20D It is a schematic plan view (right side view) showing the structure of the optical element in the fourth embodiment.

[0050] Fig.20E It is a schematic plan view (left side view) showing the structure of the optical element in the fourth embodiment.

[0051] Fig.20F It is a schematic plan view (rear view) showing the structure of the optical element in the fourth embodiment.

[0052] Figure 20G This is a schematic perspective view for explaining the structure of electrical connection of the optical element in the first embodiment.

[0053] Fig.21 1 is a timing chart showing signals input to the optical element in order to control the linear light distribution in the x-axis direction in the first embodiment.

[0054] Fig. 22 1 is a timing chart showing signals input to the optical element in order to control the linear light distribution in the y-axis direction in the first embodiment.

[0055] Fig.23 1 is a timing chart showing signals input to the optical element in order to control the light distribution having a circular shape in the first embodiment.

[0056] Fig.241 is a timing chart showing signals input to the optical element in order to control the light distribution having an elliptical shape in the first embodiment.

[0057] Fig.25 1 is a timing chart showing signals input to the optical element in order to control the light distribution having a cross shape in the first embodiment.

[0058] Fig.26 1 is another timing chart showing signals input to the optical element in order to control the light distribution having a cross shape in the first embodiment. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] <First Embodiment>

[0064] In this embodiment, refer to Figure 1 to Figure 13 , the lighting device 1 and the optical element 10 included in the lighting device 1 are described.

[0065] [1. Structure of lighting device 1]

[0066] Figure 1 : is a schematic perspective view showing the structure of the lighting device 1 in this embodiment. Figure 21 is a schematic exploded perspective view showing the structure of the optical element 10 in this embodiment. Here, the x-axis, y-axis, and z-axis are coordinate axes based on the optical element 10. In addition, hereinafter, the direction indicated by the arrow of the coordinate axis represents the + direction, and the opposite direction represents the - direction, but when the direction on the axis is not particularly limited, the + or - reference numerals are sometimes not marked.

[0067] like Figure 1 As shown, the lighting device 1 includes an optical element 10 and a light source 20. The optical element 10 includes a first liquid crystal unit 100-1, a second liquid crystal unit 100-2, a third liquid crystal unit 100-3, a fourth liquid crystal unit 100-4, a first terminal connection substrate 200-1, and a second terminal connection substrate 200-2. The details of the structure of the optical element 10 are described later. The optical element 10 can change the shape of the light, that is, the light distribution, that passes through the optical element 10 by controlling the diffusion of the light emitted from the light source 20. As the light source 20, for example, light emitting diodes (LEDs) can be used, but it is not limited to this. The light source 20 can be any element or device that can emit light.

[0068] In the optical element 10, the first terminal connection substrate 200-1, the first liquid crystal unit 100-1, the second liquid crystal unit 100-2, the third liquid crystal unit 100-3, the fourth liquid crystal unit 100-4, and the second terminal connection substrate 200-2 are stacked in order along the z-axis direction from the side close to the light source 20. That is, the optical element 10 includes four liquid crystal units 100 between two terminal connection substrates 200. In addition, the four liquid crystal units 100 overlap each other. In addition, the number of liquid crystal units 100 included in the optical element 10 is not limited to four. The optical element 10 only needs to include at least two liquid crystal units 100.

[0069] An optical elastic resin layer 300 is provided between the first terminal connection substrate 200-1 and the first liquid crystal cell 100-1, between the first liquid crystal cell 100-1 and the second liquid crystal cell 100-2, between the third liquid crystal cell 100-3 and the fourth liquid crystal cell 100-4, and between the fourth liquid crystal cell 100-4 and the second terminal connection substrate 200-2. The optical elastic resin layer 300 can adhere and fix two adjacent liquid crystal cells 100, or the terminal connection substrate 200 and the liquid crystal cell 100. As the optical elastic resin layer 300, for example, an adhesive including a light-transmitting acrylic resin can be used.

[0070] The first terminal connection substrate 200-1 and the second terminal connection substrate 200-2 are both light-transmitting substrates. For example, the first terminal connection substrate 200-1 and the second terminal connection substrate 200-2 are both glass substrates, but are not limited thereto. In addition, a plurality of terminals 210 are respectively provided on the first terminal connection substrate 200-1 and the second terminal connection substrate 200-2. The plurality of terminals 210 are respectively provided on the side surfaces of the optical element 10 and are electrically connected to the inter-unit conductive electrode 400 extending in the z-axis direction.

[0071] As the inter-cell conductive electrode 400, for example, a conductive adhesive including a conductive filler can be used. As the conductive filler, for example, silver or carbon can be used. The inter-cell conductive electrode 400 can be formed using a dispenser. Specifically, by moving the dispenser in the z-axis direction while ejecting the conductive adhesive from the nozzle of the dispenser, the inter-cell conductive electrode 400 extending in the z-axis direction can be formed on the side of the optical element 10. In addition, by utilizing the capillary phenomenon, the conductive adhesive can also be injected into the step formed on the side of the optical element 10.

[0072] The first liquid crystal cell 100 - 1 to the fourth liquid crystal cell 100 - 4 all have the same structure. That is, in the optical element 10 , four liquid crystal cells 100 having the same structure are stacked with their arrangement directions changed.

[0073] [2. Structure of Liquid Crystal Cell 100]

[0074] Figure 3 It is a schematic perspective view showing the structure of the liquid crystal cell 100 included in the optical element 10 in this embodiment. Figure 4A as well as Figure 4B Each of them is a schematic cross-sectional view showing the structure of the liquid crystal unit 100 included in the optical element 10 of this embodiment. Specifically, Figure 4A So Figure 3 A cross-sectional view of the liquid crystal unit 100 in the ca plane cut along the line A1-A2, Figure 4B So Figure 3 1 is a cross-sectional view of the liquid crystal cell 100 in the bc plane cut along the line B1 - B2 of FIG. Here, the a-axis, the b-axis, and the c-axis are coordinate axes based on the liquid crystal cell 100 .

[0075] like Figure 3As shown, the liquid crystal cell 100 is formed by laminating a first substrate 110-1 and a second substrate 110-2. The first substrate 110-1 and the second substrate 110-2 do not completely overlap, and are laminated in a manner that a portion of the surface of the first substrate 110-1 and a portion of the surface of the second substrate 110-2 are exposed. A detailed description is provided later, and a connection pad electrically connected to the inter-cell conductive electrode 400 is provided on the exposed surface of the first substrate 110-1 and the exposed surface of the second substrate 110-2.

[0076] like Figure 4A as well as Figure 4B As shown, a plurality of first transparent electrodes 120-1, a plurality of second transparent electrodes 120-2, and a first orientation film 130-1 covering the plurality of first transparent electrodes 120-1 and the plurality of second transparent electrodes 120-2 are provided on the first substrate 110-1. The first transparent electrodes 120-1 and the second transparent electrodes 120-2 are arranged alternately. In addition, a plurality of third transparent electrodes 120-3, a plurality of fourth transparent electrodes 120-4, and a second orientation film 130-2 covering the plurality of third transparent electrodes and the plurality of fourth transparent electrodes 120-4 are provided on the second substrate 110-2. The third transparent electrodes 120-3 and the fourth transparent electrodes 120-4 are arranged alternately. The first substrate 110-1 and the second substrate 110-2 are arranged in a manner that the first transparent electrodes 120-1 and the second transparent electrodes 120-2 are opposed to the third transparent electrodes 120-3 and the fourth transparent electrodes 120-4, and are bonded via a sealing material 140 provided at the periphery of the first substrate 110-1 and the second substrate 110-2. 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 .

[0077] As the first substrate 110-1 and the second substrate 110-2, a glass substrate, a quartz substrate, a sapphire substrate or other light-transmitting rigid substrates are used, respectively. In addition, as the first substrate 110-1 and the second substrate 110-2, a polyimide resin substrate, an acrylic resin substrate, a siloxane resin substrate, a fluororesin substrate or other light-transmitting flexible substrates are used, respectively.

[0078] 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. A transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is 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.

[0079] The liquid crystal layer 150 can refract 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 a twist to the liquid crystal molecules is contained in the liquid crystal.

[0080] 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 respectively. In addition, the first alignment film 130-1 and the second alignment film 130-2 can also 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.

[0081] The first alignment film 130-1 is rubbed in the a-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 a-axis direction. In addition, the second alignment film 130-2 is rubbed in the b-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 b-axis direction.

[0082] As the sealing material 140, an adhesive material including epoxy resin or acrylic resin is used. In addition, the adhesive material may be an ultraviolet curing type or a thermosetting type.

[0083] [3. Electrode Pattern of Liquid Crystal Cell 100]

[0084] Figure 5A as well as Figure 5B 1 is a schematic plan view illustrating an electrode pattern of a liquid crystal cell 100 included in an optical element 10 in this embodiment. Specifically, Figure 5A is a plan view showing an electrode pattern A formed on the first substrate 110 - 1 , Figure 5B110 - 2 is a plan view showing an electrode pattern B formed on the second substrate 110 - 2 .

[0085] like Figure 5A As shown, the electrode pattern A includes a plurality of first transparent electrodes 120-1 and a plurality of second transparent electrodes 120-2 extending along the b-axis direction. The plurality of first transparent electrodes 120-1 and the plurality of second transparent electrodes 120-2 are arranged in a comb shape. In addition, the electrode pattern A includes a first connection pad 160-1 and a second connection pad 160-2 provided on the peripheral portion of the first substrate 110-1. The plurality of first transparent electrodes 120-1 are electrically connected to the first connection pad 160-1 via the wiring WL1. In addition, the plurality of second transparent electrodes 120-2 are electrically connected to the second connection pad 160-2 via the wiring WL2.

[0086] like Figure 5B As shown, the electrode pattern B includes a plurality of third transparent electrodes 120-3 and a plurality of fourth transparent electrodes 120-4 extending along the a-axis direction. The plurality of third transparent electrodes 120-3 and the plurality of fourth transparent electrodes 120-4 are arranged in a comb shape. In addition, the electrode pattern B includes a third connection pad 160-3 and a fourth connection pad 160-4 provided on the peripheral portion of the second substrate 110-2. The plurality of third transparent electrodes 120-3 are electrically connected to the third connection pad 160-3 via wiring WL3. In addition, the plurality of fourth transparent electrodes 120-4 are electrically connected to the fourth connection pad 160-4 via wiring WL4.

[0087] The first substrate 110 - 1 and the second substrate 110 - 2 are attached to each other with the substrate being offset in the a-axis direction (see Figure 3 ). As a result, at least a portion of the first connection pad 160-1 on the first substrate 110-1 and at least a portion of the second connection pad 160-2 are exposed from the second substrate 110-2. Similarly, at least a portion of the third connection pad 160-3 and at least a portion of the fourth connection pad 160-4 on the second substrate 110-2 are exposed from the first substrate 110-1. The inter-cell conduction electrodes 400 are respectively connected to the exposed first to fourth connection pads 160-1 and 160-4. Therefore, in each of the first to fourth liquid crystal cells 100-1 to 100-4, voltages can be supplied 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 via the four inter-cell conduction electrodes 400, and the liquid crystal of the liquid crystal layer 150 can be controlled.

[0088] [4. Optical Characteristics of Liquid Crystal Cell 100]

[0089] Fig. 6A as well as Figure 6Bis a schematic diagram illustrating the optical characteristics of the liquid crystal unit 100 in this embodiment. Specifically, Fig. 6A 1 shows the liquid crystal cell 100 in a state where no voltage is applied to the transparent electrode 120. Figure 6B The liquid crystal cell 100 is shown in a state where a voltage is applied to the transparent electrode 120 .

[0090] like Fig. 6A As shown, the liquid crystal molecules on the first substrate 110-1 side of the liquid crystal layer 150 are oriented along the a-axis direction (i.e., the initial orientation direction of the liquid crystal molecules is the a-axis), and the liquid crystal molecules on the second substrate 110-2 side of the liquid crystal layer 150 are oriented along the b-axis direction (i.e., the initial orientation direction of the liquid crystal molecules is the b-axis). Therefore, when no voltage is applied to the first transparent electrode 120-1 to the fourth transparent electrode 120-4, the liquid crystal molecules in the liquid crystal layer 150 are oriented in a manner of twisting 90° in the c-axis direction as they move from the first substrate 110-1 toward the second substrate 110-2. In addition, the polarization plane (polarization axis or polarization component orientation) 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.

[0091] On the other hand, when a voltage is applied so as to generate a potential difference between two adjacent transparent electrodes 120, an electric field (hereinafter referred to as a "lateral electric field") is generated between the two adjacent transparent electrodes 120, and the orientation of the liquid crystal molecules changes. Figure 6B As shown, the liquid crystal molecules in the liquid crystal layer 150 are oriented in a manner of twisting 90° in the c-axis direction as they move from the first substrate 110-1 toward the second substrate 110-2, and at the same time, the liquid crystal molecules near the first substrate 110-1 side are oriented in a convex arc shape 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, and the liquid crystal molecules near the second substrate 110-2 side are oriented in a convex arc shape 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. The liquid crystal molecules oriented in a convex arc shape have a refractive index distribution, and light having the same polarization direction as the orientation direction of the liquid crystal molecules is diffused. In addition, 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 (eg, 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.

[0092] from Figure 1The light emitted from the light source 20 shown 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"), but for convenience, the light emitted from the light source 20 is divided into a first light 1000-1 having a P polarization component and a second light 1000-2 having an S polarization component for description. In addition, for convenience, the x-axis direction and the y-axis direction are respectively described as corresponding to the a-axis direction and the b-axis direction.

[0093] Since the P polarization component of the first light 1000-1 incident from the first substrate 110-1 side is aligned in the same direction as the liquid crystal molecules on the first substrate 110-1 side, the first light 1000-1 is diffused in the a-axis direction according to the refractive index distribution of the liquid crystal molecules (refer to Figure 6B (1)). In addition, the first light 1000-1 undergoes optical rotation in the process of passing through the liquid crystal layer 150, and the polarization component changes from the P polarization component to the S polarization component. Since the S polarization component of the first light 1000-1 is in the same orientation direction as the liquid crystal molecules on the second substrate 110-2 side, the first light 1000-1 diffuses in the b-axis direction according to the refractive index distribution of the liquid crystal molecules.

[0094] Since the S polarization component of the second light 1000-2 incident from the first substrate 110-1 side is different from the alignment direction of the liquid crystal molecules on the first substrate 110-1 side, the second light 1000-2 does not diffuse (refer to Figure 6B (2)). In addition, the second 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 light 1000-2 is different from the orientation direction of the liquid crystal molecules on the second substrate 110-2 side, the second light 1000-2 does not diffuse.

[0095] Since the P polarization component of the first light 1000-1 incident from the second substrate 110-2 side is different from the alignment direction of the liquid crystal molecules on the second substrate 110-2 side, the first light 1000-1 is not diffused (refer to Figure 6B (3)). In addition, the second light 1000-2 undergoes optical rotation in the process of passing through the liquid crystal layer 150, and the polarization component changes from the P polarization component to the S polarization component. Since the S polarization component of the first light 1000-1 is different from the orientation direction of the liquid crystal molecules on the first substrate 110-1 side, the first light 1000-1 does not diffuse.

[0096] Since the S polarization component of the second light 1000-2 incident from the second substrate 110-2 side is in the same direction as the alignment direction of the liquid crystal molecules on the second substrate 110-2 side, the second light 1000-2 is diffused in the b-axis direction according to the refractive index distribution of the liquid crystal molecules (refer to Figure 6B(4)). In addition, the second 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 S polarization component of the first light 1000-1 is aligned in the same direction as the liquid crystal molecules on the second substrate 110-2 side, the first light 1000-1 diffuses in the b-axis direction according to the refractive index distribution of the liquid crystal molecules.

[0097] In addition, in the above, an example of diffusing light on both sides of the first substrate 110-1 side and the second substrate 110-2 side is described, but when a voltage is applied to the transparent electrode 120 on one substrate 110 without applying a voltage to the transparent electrode 120 on the other substrate 110, light can also be diffused only on one substrate 110 side.

[0098] [5. Electrical connection structure of optical element 10]

[0099] Figure 7A to Figure 7F 1 is a plan view illustrating the structure of electrical connection of the optical element 10 in this embodiment. Specifically, Figure 7A to Figure 7F 1 and 2 respectively show a top view, a bottom view, a front view, a right side view, a left side view, and a rear view of the optical element 10. Figure 7G 1 is a schematic perspective view for explaining the structure of electrical connection of the optical element 10 in this embodiment. Figure 7G 2 shows the electrical connection of the transparent electrodes 120 of the liquid crystal cells 100 in the optical element 10 .

[0100] First, refer to Figure 7A to Figure 7G, the arrangement directions of the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4 are described. The first liquid crystal unit 100-1 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the +x axis direction, +y axis direction and +z axis direction of the optical element 10, respectively. The second liquid crystal unit 100-2 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the -y axis direction, -x axis direction and -z axis direction of the optical element 10, respectively. The third liquid crystal unit 100-3 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the +x axis direction, +y axis direction and +z axis direction of the optical element 10, respectively. The fourth liquid crystal unit 100-4 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the -y axis direction, -x axis direction and -z axis direction of the optical element 10, respectively. In this case, the second substrate 110-2 of the first liquid crystal unit 100-1 is opposite to the second substrate 110-2 of the second liquid crystal unit 100-2, the first substrate 110-1 of the second liquid crystal unit 100-2 is opposite to the first substrate 110-1 of the third liquid crystal unit 100-3, and the second substrate 110-2 of the third liquid crystal unit 100-3 is opposite to the second substrate 110-2 of the fourth liquid crystal unit 100-4.

[0101] In other words, the configuration directions of the third liquid crystal unit 100-3 and the fourth liquid crystal unit 100-4 are respectively the same as the configuration directions of the first liquid crystal unit 100-1 and the second liquid crystal unit 100-2. The configuration direction of the second liquid crystal unit 100-2 is the same as the configuration direction of the first liquid crystal unit 100-1 after being turned upside down and rotated 90°. Similarly, the configuration direction of the fourth liquid crystal unit is the same as the configuration direction of the third liquid crystal unit 100-3 after being turned upside down and rotated 90°. In addition, as Fig. 7A as well as Figure 7B As shown, the planar shape of the liquid crystal cell 100 is substantially square, and when viewed from above, the corners of the first liquid crystal cell 100 - 1 to the fourth liquid crystal cell 100 - 4 are substantially aligned.

[0102] In the optical element 10 including the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4 having the above-mentioned configuration direction, the diffusion of the P-polarized component of the light can be controlled by the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3, and the diffusion of the S-polarized component of the light can be controlled by the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4, as will be described later.

[0103] Next, refer to Figure 7A to Figure 7G , the structure of the electrical connection of the optical element 10 is described.

[0104] A third inter-cell conducting electrode 400-3 and a fourth inter-cell conducting electrode 400-4 are provided on the first side surface (front surface) of the optical element 10. A fifth inter-cell conducting electrode 400-5 and a sixth inter-cell conducting electrode 400-6 are provided on the second side surface (right side surface) of the optical element 10. A seventh inter-cell conducting electrode 400-7 and an eighth inter-cell conducting electrode 400-8 are provided on the third side surface (left side surface) of the optical element 10. A first inter-cell conducting electrode 400-1 and a second inter-cell conducting electrode 400-2 are provided on the fourth side surface (back surface) of the optical element 10.

[0105] The first inter-cell conduction electrode 400-1 is electrically connected to the first terminal 210-1 on the first terminal connection substrate 200-1. In addition, the first inter-cell conduction electrode 400-1 is electrically connected to the first connection pad 160-1 of the first liquid crystal cell 100-1 and the first connection pad 160-1 of the third liquid crystal cell 100-3. Therefore, the first terminal 210-1 is electrically connected to the first transparent electrode 120-1 of the first liquid crystal cell 100-1 and the first transparent electrode 120-1 of the third liquid crystal cell 100-3 via the first inter-cell conduction electrode 400-1.

[0106] The second inter-cell conduction electrode 400-2 is electrically connected to the second terminal 210-2 on the first terminal connection substrate 200-1. In addition, the second inter-cell conduction electrode 400-2 is electrically connected to the second connection pad 160-2 of the first liquid crystal cell 100-1 and the second connection pad 160-2 of the third liquid crystal cell 100-3. Therefore, the second terminal 210-2 is electrically connected to the second transparent electrode 120-2 of the first liquid crystal cell 100-1 and the second transparent electrode 120-2 of the third liquid crystal cell 100-3 via the second inter-cell conduction electrode 400-2.

[0107] The third inter-cell conduction electrode 400-3 is electrically connected to the third terminal 210-3 on the first terminal connection substrate 200-1. In addition, the third inter-cell conduction electrode 400-3 is electrically connected to the third connection pad 160-3 of the first liquid crystal cell 100-1 and the third connection pad 160-3 of the third liquid crystal cell 100-3. Therefore, the third terminal 210-3 is electrically connected to the third transparent electrode 120-3 of the first liquid crystal cell 100-1 and the third transparent electrode 120-3 of the third liquid crystal cell 100-3 via the third inter-cell conduction electrode 400-3.

[0108] The fourth inter-cell conduction electrode 400-4 is electrically connected to the fourth terminal 210-4 on the first terminal connection substrate 200-1. In addition, the fourth inter-cell conduction electrode 400-4 is electrically connected to the fourth connection pad 160-4 of the first liquid crystal cell 100-1 and the fourth connection pad 160-4 of the third liquid crystal cell 100-3. Therefore, the fourth terminal 210-4 is electrically connected to the fourth transparent electrode 120-4 of the first liquid crystal cell 100-1 and the fourth transparent electrode 120-4 of the third liquid crystal cell 100-3 via the fourth inter-cell conduction electrode 400-4.

[0109] The fifth inter-cell conduction electrode 400-5 is electrically connected to the fifth terminal 210-5 on the second terminal connection substrate 200-2. In addition, the fifth inter-cell conduction electrode 400-5 is electrically connected to the first connection pad 160-1 of the second liquid crystal cell 100-2 and the first connection pad 160-1 of the fourth liquid crystal cell 100-4. Therefore, the fifth terminal 210-5 is electrically connected to the first transparent electrode 120-1 of the second liquid crystal cell 100-2 and the first transparent electrode 120-1 of the fourth liquid crystal cell 100-4 via the fifth inter-cell conduction electrode 400-5.

[0110] The sixth inter-cell conduction electrode 400-6 is electrically connected to the sixth terminal 210-6 on the second terminal connection substrate 200-2. In addition, the sixth inter-cell conduction electrode 400-6 is electrically connected to the second connection pad 160-2 of the second liquid crystal cell 100-2 and the second connection pad 160-2 of the fourth liquid crystal cell 100-4. Therefore, the sixth terminal 210-6 is electrically connected to the second transparent electrode 120-2 of the second liquid crystal cell 100-2 and the second transparent electrode 120-2 of the fourth liquid crystal cell 100-4 via the sixth inter-cell conduction electrode 400-6.

[0111] The seventh inter-cell conduction electrode 400-7 is electrically connected to the seventh terminal 210-7 on the second terminal connection substrate 200-2. In addition, the seventh inter-cell conduction electrode 400-7 is electrically connected to the third connection pad 160-3 of the second liquid crystal cell 100-2 and the third connection pad 160-3 of the fourth liquid crystal cell 100-4. Therefore, the seventh terminal 210-7 is electrically connected to the third transparent electrode 120-3 of the second liquid crystal cell 100-2 and the third transparent electrode 120-3 of the fourth liquid crystal cell 100-4 via the seventh inter-cell conduction electrode 400-7.

[0112] The eighth inter-cell conduction electrode 400-8 is electrically connected to the eighth terminal 210-8 on the second terminal connection substrate 200-2. In addition, the eighth inter-cell conduction electrode 400-8 is electrically connected to the fourth connection pad 160-4 of the second liquid crystal cell 100-2 and the fourth connection pad 160-4 of the fourth liquid crystal cell 100-4. Therefore, the eighth terminal 210-8 is electrically connected to the fourth transparent electrode 120-4 of the second liquid crystal cell 100-2 and the fourth transparent electrode 120-4 of the fourth liquid crystal cell 100-4 via the eighth inter-cell conduction electrode 400-8.

[0113] As described above, the inter-cell conductive electrode 400 electrically connects the two connection pads 160 included in the two different liquid crystal cells 100, and electrically connects the two connection pads 160 to the terminal 210. Thus, by inputting a signal to one terminal 210, a voltage corresponding to the signal can be simultaneously applied to the two transparent electrodes 120 included in the two different liquid crystal cells 100.

[0114] Specifically, if Figure 7GAs shown, the first signal S1 input to the first terminal 210-1 is input to the first transparent electrode 120-1 of the first liquid crystal cell 100-1 and the third liquid crystal cell 100-3 via the first inter-cell conduction electrode 400-1. The second signal S2 input to the second terminal 210-2 is input to the second transparent electrode 120-2 of the first liquid crystal cell 100-1 and the third liquid crystal cell 100-3 via the second inter-cell conduction electrode 400-2. The third signal S3 input to the third terminal 210-3 is input to the third transparent electrode 120-3 of the first liquid crystal cell 100-1 and the third liquid crystal cell 100-3 via the third inter-cell conduction electrode 400-3. The fourth signal S4 input to the fourth terminal 210-4 is input to the fourth transparent electrode 120-4 of the first liquid crystal cell 100-1 and the third liquid crystal cell 100-3 via the fourth inter-cell conduction electrode 400-4. The fifth signal S5 input to the fifth terminal 210-5 is input to the first transparent electrode 120-1 of each of the second liquid crystal cell 100-2 and the fourth liquid crystal cell 100-4 via the fifth inter-cell conduction electrode 400-5. The sixth signal S6 input to the sixth terminal 210-6 is input to the second transparent electrode 120-2 of each of the second liquid crystal cell 100-2 and the fourth liquid crystal cell 100-4 via the sixth inter-cell conduction electrode 400-6. The seventh signal S7 input to the seventh terminal 210-7 is input to the third transparent electrode 120-3 of each of the second liquid crystal cell 100-2 and the fourth liquid crystal cell 100-4 via the seventh inter-cell conduction electrode 400-7. The eighth signal S8 input to the eighth terminal 210-8 is input to the fourth transparent electrode 120-4 of each of the second liquid crystal cell 100-2 and the fourth liquid crystal cell 100-4 via the eighth inter-cell conduction electrode 400-8.

[0115] [6. Light distribution control of optical element 10]

[0116] The optical element 10 can perform light distribution control having various shapes by inputting a signal to the terminal 210. The first signal S1 to the eighth signal S8 input to the first terminal 210-1 to the eighth terminal 210-8 are described below. In addition, for convenience, the middle voltage between the high voltage and the low voltage is set to 0V for description below, but the value of the middle voltage is not limited to 0V. For example, when the high voltage and the low voltage are 30V and 0V respectively, the middle potential can also be 15V.

[0117] [6-1. Line shape extending toward the x-axis direction]

[0118] Figure 8 1 is a timing chart showing signals input to the optical element 10 in order to control the linear light distribution in the x-axis direction in the present embodiment.

[0119] like Figure 8 As shown, the first signal S1, the second signal S2, the seventh signal S7 and the eighth signal S8 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the first signal S1 and the second signal S2 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In addition, the third signal S3 to the sixth signal S6 are 0V respectively. In this case, a transverse electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 by the first signal S1 and the second signal S2. Therefore, the P polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3. In addition, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 by the seventh signal S7 and the eighth signal S8. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4. Therefore, the light is diffused in the x-axis direction in any of the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4, so the light transmitted through the optical element 10 has a linear shape extending toward the x-axis direction. In addition, the diffusion width in the x-axis direction (the light distribution angle in the x-axis direction) can be controlled by adjusting the potential difference between the high potential and the low potential. For example, when the potential difference becomes larger, the diffusion width in the x-axis direction becomes larger.

[0120] [6-2. Line shape extending toward the y-axis direction]

[0121] Fig. 9 1 is a timing chart showing signals input to the optical element 10 in order to control the linear light distribution in the y-axis direction in the present embodiment.

[0122] like Fig. 9As shown, the third signal S3 to the sixth signal S6 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the third signal S3 and the fourth signal S4 are reversed, and the phases of the fifth signal S5 and the sixth signal S6 are reversed. In addition, the first signal S1, the second signal S2, the seventh signal S7, and the eighth signal S8 are 0V, respectively. In this case, a transverse electric field in the y-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 by the third signal S3 and the fourth signal S4. Therefore, the P-polarized component of the light emitted from the light source 20 diffuses only in the y-axis direction in the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 by the fifth signal S5 and the sixth signal S6. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the y-axis direction in the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4. Therefore, the light is diffused in the y-axis direction in any of the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4, so the light transmitted through the optical element 10 has a linear shape extending toward the y-axis direction. In addition, the diffusion width in the y-axis direction (the light distribution angle in the y-axis direction) can be controlled by adjusting the potential difference between the high potential and the low potential. For example, when the potential difference becomes larger, the diffusion width in the y-axis direction becomes larger.

[0123] [6-3.Circular shape]

[0124] Fig.10 1 is a timing chart showing signals input to the optical element 10 in order to control the light distribution having a circular shape in the present embodiment.

[0125] like Fig.10As shown, the first signal S1 to the eighth signal S8 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the first signal S1 and the second signal are reversed, the phases of the third signal S3 and the fourth signal S4 are reversed, the phases of the fifth signal S5 and the sixth signal S6 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In this case, a transverse electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of each of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 by the first signal S1 and the second signal S2. Furthermore, a transverse electric field in the y-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of each of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 by the third signal S3 and the fourth signal S4. Therefore, the P polarization component of the light emitted from the light source 20 is diffused not only in the x-axis direction but also in the y-axis direction in the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of each of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 by the fifth signal S5 and the sixth signal S6. Furthermore, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of each of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 by the seventh signal S7 and the eighth signal S8. Therefore, the S polarization component of the light emitted from the light source 20 is diffused not only in the x-axis direction but also in the y-axis direction in the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4. Therefore, the light in any of the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4 is diffused in the x-axis direction and the y-axis direction, so the light that has passed through the optical element 10 has a circular shape that expands in the x-axis direction and the y-axis direction.

[0126] [6-4. Elliptical shape]

[0127] Fig.11 1 is a timing chart showing signals input to the optical element 10 in order to control the light distribution having an elliptical shape in the present embodiment.

[0128] Fig.11 The timing diagram shown is similar to Fig.10 The timing diagrams shown are substantially the same, but the voltage amplitudes of the first signal S1 to the eighth signal S8 are different. Fig.11As shown, the amplitude a of the first signal S1, the second signal S2, the seventh signal S7 and the eighth signal S8 is different from the amplitude b of the third signal S3 to the sixth signal S6. The diffusion in the x-axis direction and the y-axis direction corresponds to the amplitude a and the amplitude b, respectively. Therefore, in the case of a>b, the light passing through the optical element 10 diffuses more in the x-axis direction than in the y-axis direction, and has an elliptical shape with a major axis in the x-axis direction. On the other hand, in the case of a<b, the light passing through the optical element 10 diffuses more in the y-axis direction than in the x-axis direction, and has an elliptical shape with a major axis in the y-axis direction.

[0129] [6-5. Cross shape]

[0130] Fig.12 1 is a timing chart showing signals input to the optical element 10 in order to control light distribution having a cross shape in the present embodiment.

[0131] like Fig.12 As shown, the third signal S3, the fourth signal S4, the seventh signal S7 and the eighth signal S8 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the third signal S3 and the fourth signal S4 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In addition, the first signal S1, the second signal S2, the fifth signal S5 and the sixth signal S6 are 0V respectively. In this case, a transverse electric field in the y-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 respectively by the third signal S3 and the fourth signal S4. Therefore, the P polarization component of the light emitted from the light source 20 is diffused only in the y-axis direction in the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3. In addition, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 respectively by the seventh signal S7 and the eighth signal S8. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4. Therefore, the P polarization component and the S polarization component are diffused only in one direction of the x-axis direction and the y-axis direction, respectively, so that the light transmitted through the optical element 10 has a cross shape that selectively expands in the x-axis direction and the y-axis direction. In addition, the diffusion width in the x-axis direction (light distribution angle in the x-axis direction) and the diffusion width in the y-axis direction (light distribution angle in the y-axis direction) can be controlled by adjusting the amplitude a and the amplitude b, respectively.

[0132] In addition, the timing chart for controlling the light distribution having a cross shape is not limited to Fig.12 The following is the timing diagram. Fig.13 , a modified example of a timing diagram for controlling a light distribution having a cross shape is described.

[0133] Fig.13 1 is another timing chart showing signals input to the optical element 10 in order to control the light distribution having a cross shape in the present embodiment.

[0134] like Fig.13 As shown, the first signal S1, the second signal S2, the fifth signal S5 and the sixth signal S6 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the first signal S1 and the second signal S2 are reversed, and the phases of the fifth signal S5 and the sixth signal S6 are reversed. In addition, the third signal S3, the fourth signal S4, the seventh signal S7 and the eighth signal S8 are 0V respectively. In this case, a transverse electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3 by the first signal S1 and the second signal S2. Therefore, the P polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the first liquid crystal unit 100-1 and the third liquid crystal unit 100-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4 by the fifth signal S5 and the sixth signal S6. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the y-axis direction in the second liquid crystal unit 100-2 and the fourth liquid crystal unit 100-4. Therefore, the P polarization component and the S polarization component are diffused only in one direction of the x-axis direction and the y-axis direction, respectively, so that the light transmitted through the optical element 10 has a cross shape that selectively expands in the x-axis direction and the y-axis direction. In addition, the diffusion width in the x-axis direction (the light distribution angle in the x-axis direction) and the diffusion width in the y-axis direction (the light distribution angle in the y-axis direction) can be controlled by adjusting the amplitude b and the amplitude a, respectively.

[0135] As described above, in this embodiment, the light distribution can be controlled by applying voltage to the plurality of transparent electrodes 120 included in the plurality of liquid crystal cells 100 at the same time through the inter-cell conduction electrode 400 provided on the side of the optical element 10. Therefore, the number of signals input to the optical element 10 can be reduced, and the control of the light distribution of the optical element 10 is simplified. Furthermore, since the number of terminals 210 electrically connected to the transparent electrodes 120 is reduced, the wiring connection in the mounting process (for example, the connection of the FPC, the lead bonding member to the terminal 210 or the inter-cell conduction electrode 400) is simplified, and the manufacturing yield of the optical element 10 is improved. In addition, the lighting device 1 including the optical element 10 is also excellent in the control of light distribution, and the manufacturing yield is improved.

[0136] <Second Embodiment>

[0137] In this embodiment, refer to Fig.14 as well as Fig.15 , the lighting device 1A and the optical element 10A included in the lighting device 1A are described. In addition, when the structures of the lighting device 1A and the optical element 10A are the same as the structures of the lighting device 1 and the optical element 10 described in the first embodiment, the description of the structures of the lighting device 1A and the optical element 10A is sometimes omitted.

[0138] Fig.14 1A is a schematic perspective view showing the structure of the lighting device 1A in this embodiment. Fig.15 1 is a schematic plan view showing the structure of the optical element 10A in this embodiment. Specifically, Fig.15 A top view of the optical element 10A is shown.

[0139] like Fig.14 As shown, the lighting device 1A includes an optical element 10A and a light source 20. The optical element 10A includes a first liquid crystal cell 100-1, a second liquid crystal cell 100-2, a third liquid crystal cell 100-3, a fourth liquid crystal cell 100-4, and a terminal connection substrate 200A. In the optical element 10A, the terminal connection substrate 200A, 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 stacked in order from the side close to the light source 20 in the z-axis direction. The structure and arrangement direction of the four liquid crystal cells 100 included in the optical element 10A are the same as the structure and arrangement direction of the four liquid crystal cells 100 described in the first embodiment.

[0140] A third inter-cell conductive electrode 400A-3 and a fourth inter-cell conductive electrode 400A-4 are provided on the first side surface of the optical element 10A. A fifth inter-cell conductive electrode 400A-5 and a sixth inter-cell conductive electrode 400A-6 are provided on the second side surface of the optical element 10A. A seventh inter-cell conductive electrode 400A-7 and an eighth inter-cell conductive electrode 400A-8 are provided on the third side surface of the optical element 10A. A first inter-cell conductive electrode 400A-1 and a second inter-cell conductive electrode 400A-2 are provided on the fourth side surface of the optical element 10A.

[0141] like Fig.15As shown, the first terminal 210A-1 to the eighth terminal 210A-8 are provided on the terminal connection substrate 200A. In addition, the first terminal 210A-1 to the eighth terminal 210A-8 are electrically connected to the first inter-unit conductive electrode 400A-1 to the eighth inter-unit conductive electrode 400A-8, respectively. That is, in the optical element 10A, the terminals 210A electrically connected to the inter-unit conductive electrode 400A are gathered on one terminal connection substrate 200A. In addition, the terminal connection substrate 200A can also be arranged adjacent to the fourth liquid crystal unit 100-4. In the optical element 10A, there is a structure in which only one terminal connection substrate 200A is arranged on one of the upper surface or the bottom surface of the optical element 10A.

[0142] As described above, in this embodiment, the light distribution can be controlled by applying voltage to the plurality of transparent electrodes 120 included in the plurality of liquid crystal cells 100 at the same time through the inter-cell conductive electrode 400A provided on the side of the optical element 10A. The inter-cell conductive electrode 400A is electrically connected to the terminal 210A on a terminal connection substrate 200A disposed on the upper surface or the bottom surface of the optical element 10A. Therefore, the number of terminal connection substrates 200A is reduced, so the wiring connection in the mounting process can be further simplified, and the manufacturing yield of the optical element 10A is improved. In addition, the lighting device 1A including the optical element 10A is also excellent in the control of light distribution, and the manufacturing yield is improved.

[0143] <Third Embodiment>

[0144] In this embodiment, refer to Figure 16~Figure 17F , the lighting device 1B and the optical element 10B included in the lighting device 1B are described. In addition, when the structures of the lighting device 1B and the optical element 10B are the same as the structures of the lighting device 1 and the optical element 10 described in the first embodiment, the description of the structures of the lighting device 1B and the optical element 10B is sometimes omitted.

[0145] Fig.16 1B is a schematic perspective view showing the structure of the lighting device 1B in this embodiment. Figure 17A to Figure 17F 1 is a schematic plan view showing the structure of the optical element 10B in this embodiment. Specifically, Figure 17A to Figure 17F A top view, a bottom view, a front view, a right side view, a left side view, and a rear view of the optical element 10B are respectively shown.

[0146] like Fig.16As shown, the lighting device 1B includes an optical element 10B and a light source 20. The optical element 10B includes a first liquid crystal cell 100B-1, a second liquid crystal cell 100B-2, a third liquid crystal cell 100B-3, a fourth liquid crystal cell 100B-4, a first terminal connection substrate 200B-1, and a second terminal connection substrate 200B-2. In the optical element 10B, the first terminal connection substrate 200B-1, the first liquid crystal cell 100B-1, the second liquid crystal cell 100B-2, the third liquid crystal cell 100B-3, the fourth liquid crystal cell 100B-4, and the second terminal connection substrate 200B-2 are stacked in order from the side close to the light source 20 in the z-axis direction. The planar shape of the liquid crystal cell 100B is different from the planar shape of the liquid crystal cell 100 described in the first embodiment. However, the structure of the liquid crystal cell 100B other than the planar shape is the same as that of the liquid crystal cell 100. The arrangement direction of the four liquid crystal cells included in the optical element 10B is the same as the arrangement direction of the four liquid crystal cells 100 described in the first embodiment.

[0147] like Fig.17A as well as Fig. 17B As shown, the planar shape of the liquid crystal unit 100B is a substantially rectangular shape having short sides and long sides. Therefore, the corners of the first liquid crystal unit 100-1 to the fourth liquid crystal unit are not consistent. In addition, in the optical element 10B, the connection pad 160 is provided on the short side of the liquid crystal unit 100B and exposed on the side of the optical element 10B.

[0148] The inter-cell conductive electrode 400B (the first inter-cell conductive electrode 400B-1 to the eighth inter-cell conductive electrode 400B-8) extends along the z-axis direction on the side surface of the optical element 10B, and electrically connects the connection pads 160 (the first connection pad 160-1 to the fourth connection pad 160-4) exposed on the side surface of the optical element 10B to the terminal 210 on the terminal connection substrate 200B. The first inter-cell conductive electrode 400B-1 is provided on the fourth side surface (back surface), and electrically connects the first connection pad 160-1 of the first liquid crystal cell 100B-1 and the first connection pad 160-1 of the third liquid crystal cell 100B-3 to the first terminal 210-1 on the first terminal connection substrate 200B-1. The second inter-cell conduction electrode 400B-2 is provided on the fourth side surface (rear surface) to electrically connect the second connection pad 160-2 of the first liquid crystal cell 100B-1 and the second connection pad 160-2 of the third liquid crystal cell 100B-3 to the second terminal 210-2 on the first terminal connection substrate 200B-1. The third inter-cell conduction electrode 400B-3 is provided on the first side surface (front surface) to electrically connect the third connection pad 160-3 of the first liquid crystal cell 100B-1 and the third connection pad 160-3 of the third liquid crystal cell 100B-3 to the third terminal 210-3 on the first terminal connection substrate 200B-1. The fourth inter-cell conduction electrode 400B-4 is provided on the first side surface (front surface) to electrically connect the fourth connection pad 160-4 of the first liquid crystal cell 100B-1 and the fourth connection pad 160-4 of the third liquid crystal cell 100B-3 to the fourth terminal 210-4 on the first terminal connection substrate 200B-1. The fifth inter-cell conduction electrode 400B-5 is provided on the second side surface (right side surface) and electrically connects the first connection pad 160-1 of the second liquid crystal cell 100B-2 and the first connection pad 160-1 of the fourth liquid crystal cell 100B-4 to the fifth terminal 210-5 on the second terminal connection substrate 200B-2. The sixth inter-cell conduction electrode 400B-6 is provided on the second side surface (right side surface) and electrically connects the second connection pad 160-2 of the second liquid crystal cell 100B-2 and the second connection pad 160-2 of the fourth liquid crystal cell 100B-4 to the sixth terminal 210-6 on the second terminal connection substrate 200B-2. The seventh inter-cell conduction electrode 400B-7 is provided on the third side surface (left side surface) and electrically connects the third connection pad 160-3 of the second liquid crystal cell 100B-2 and the third connection pad 160-3 of the fourth liquid crystal cell 100B-4 to the seventh terminal 210-7 on the second terminal connection substrate 200B-2. The eighth inter-unit conductive electrode 400B-8 is provided on the third side surface (left side surface) and electrically connects the fourth connection pad 160-4 of the second liquid crystal unit 100B-2 and the fourth connection pad 160-4 of the fourth liquid crystal unit 100B-4 to the eighth terminal 210-8 on the second terminal connection substrate 200B-2.

[0149] In the optical element 10B, the planar shape of the liquid crystal cell 100B is substantially rectangular, so only the substrate 110 provided with the connection pad 160 protrudes from the side surface of the optical element 10B. Therefore, the distance between the two substrates 110 provided with the connection pad 160 to which the inter-cell conductive electrode 400B is electrically connected can be increased. In other words, a large step is formed on the side surface of the optical element 10B. Therefore, since more conductive adhesive is injected into the step formed between the two substrates 110, disconnection of the inter-cell conductive electrode 400B can be prevented.

[0150] As described above, in this embodiment, the light distribution can be controlled by applying voltage to the plurality of transparent electrodes 120 included in the plurality of liquid crystal cells 100B at the same time through the inter-cell conduction electrode 400B provided on the side of the optical element 10B. Since the conductive adhesive constituting the inter-cell conduction electrode 400B is injected more into the larger step formed on the side of the optical element 10B, the inter-cell conduction electrode 400B can be prevented from being disconnected, and the manufacturing yield of the optical element 10B is improved. In addition, the lighting device 1B including the optical element 10B also has excellent control over light distribution and improves the manufacturing yield.

[0151] <Fourth Embodiment>

[0152] In this embodiment, refer to Figure 18~Figure 20G , the lighting device 1C and the optical element 10C included in the lighting device 1C are described. In addition, when the structures of the lighting device 1C and the optical element 10C are the same as the structures of the lighting device 1 and the optical element 10 described in the first embodiment, the description of the structures of the lighting device 1C and the optical element 10C is sometimes omitted.

[0153] [1. Structure of lighting device 1C]

[0154] Fig.18 It is a schematic perspective view showing the structure of a lighting device 1C in this embodiment. Fig.19 It is a schematic exploded perspective view showing the structure of an optical element 10C in this embodiment. Figure 20A to Figure 20F 1 is a plan view illustrating the electrical connection structure of the optical element 10C in this embodiment. Specifically, Figure 20A to Figure 20F 10C respectively represent a top view, a bottom view, a front view, a right side view and a rear view of the optical element 10C. Figure 20G 1 is a schematic perspective view for explaining the electrical connection structure of the optical element 10C in this embodiment. Figure 20G 2 shows the electrical connection of the transparent electrodes 120 of the liquid crystal cells 100C in the optical element 10C.

[0155] like Fig.18 As shown, the lighting device 1C includes an optical element 10C and a light source 20. The optical element 10C includes a first liquid crystal cell 100C-1, a second liquid crystal cell 100C-2, a third liquid crystal cell 100C-3, a fourth liquid crystal cell 100C-4, a first terminal connection substrate 200C-1, and a second terminal connection substrate 200C-2. In addition, in the optical element 10C, the first terminal connection substrate 200C-1, the first liquid crystal cell 100C-1, the second liquid crystal cell 100C-2, the third liquid crystal cell 100C-3, the fourth liquid crystal cell 100C-4, and the second terminal connection substrate 200C-2 are stacked in order from the side close to the light source 20 in the z-axis direction.

[0156] The structures of the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 are the same as the structure of the liquid crystal unit 100 described in the first embodiment. However, the arrangement direction of the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 is different from the arrangement direction of the first liquid crystal unit 100-1 to the fourth liquid crystal unit 100-4 described in the first embodiment. For this reason, refer to Figure 20A to Figure 20G , the arrangement directions of the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 are described. The first liquid crystal unit 100C-1 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the +y axis direction, -x axis direction and +z axis direction of the optical element 10C, respectively. The second liquid crystal unit 100C-2 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the -x axis direction, +y axis direction and -z axis direction of the optical element 10C, respectively. The third liquid crystal unit 100C-3 is arranged in such a manner that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal unit 100 correspond to the +x axis direction, -y axis direction and -z axis direction of the optical element 10C, respectively. The fourth liquid crystal cell 100C-4 is arranged so that the +a axis direction, +b axis direction and +c axis direction of the liquid crystal cell 100 correspond to the -y axis direction, -x axis direction and -z axis direction of the optical element 10C, respectively.

[0157] Therefore, on the first side surface (front surface) of the optical element 10C, the first connection pad 160-1 and the second connection pad 160-2 of the second liquid crystal cell 100C-2 and the first connection pad 160-1 and the second connection pad 160-2 of the third liquid crystal cell 100C-3 are exposed. In addition, on the second side surface (right side surface) of the optical element 10C, the first connection pad 160-1 and the second connection pad 160-2 of the first liquid crystal cell 100C-1 and the first connection pad 160-1 and the second connection pad 160-2 of the fourth liquid crystal cell 100C-4 are exposed. In addition, on the third side surface (left side surface) of the optical element 10C, the third connection pad 160-3 and the fourth connection pad 160-4 of the first liquid crystal cell 100C-1 and the third connection pad 160-3 and the fourth connection pad 160-4 of the fourth liquid crystal cell 100C-4 are exposed. In addition, on the fourth side surface (rear surface) of the optical element 10C, the third connection pad 160-3 and the fourth connection pad 160-4 of the second liquid crystal cell 100C-2 and the third connection pad 160-3 and the fourth connection pad 160-4 of the third liquid crystal cell 100C-3 are exposed.

[0158] The inter-cell conductive electrode 400C extends along the z-axis direction on the side surface of the optical element 10C, and electrically connects the connection pad 160 exposed on the side surface of the optical element 10C to the terminal 210 on the terminal connection substrate 200C. The first inter-cell conductive electrode 400C-1 is provided on the fourth side surface (back surface), and electrically connects the third connection pad 160-3 of the second liquid crystal cell 100C-2 and the fourth connection pad 160-4 of the third liquid crystal cell 100C-3 to the first terminal 210-1 on the first terminal connection substrate 200C-1. The second inter-cell conductive electrode 400C-2 is provided on the fourth side surface (back surface), and electrically connects the fourth connection pad 160-4 of the second liquid crystal cell 100C-2 and the third connection pad 160-3 of the third liquid crystal cell 100C-3 to the second terminal 210-2 on the first terminal connection substrate 200C-1. The third inter-cell conduction electrode 400C-3 is provided on the first side surface (front surface) to electrically connect the first connection pad 160-1 of the second liquid crystal cell 100C-2 and the second connection pad 160-2 of the third liquid crystal cell 100C-3 to the third terminal 210-3 on the first terminal connection substrate 200C-1. The fourth inter-cell conduction electrode 400C-4 is provided on the first side surface (front surface) to electrically connect the second connection pad 160-2 of the second liquid crystal cell 100C-2 and the first connection pad 160-1 of the third liquid crystal cell 100C-3 to the fourth terminal 210-4 on the first terminal connection substrate 200C-1. The fifth inter-cell conduction electrode 400C-5 is provided on the second side surface (right side surface) to electrically connect the second connection pad 160-2 of the first liquid crystal cell 100C-1 and the first connection pad 160-1 of the fourth liquid crystal cell 100C-4 to the fifth terminal 210-5 on the second terminal connection substrate 200C-2. The sixth inter-unit conductive electrode 400C-6 is provided on the second side surface (right side surface), and electrically connects the first connection pad 160-1 of the first liquid crystal unit 100C-1 and the second connection pad 160-2 of the fourth liquid crystal unit 100C-4 to the sixth terminal 210-6 on the second terminal connection substrate 200C-2. The seventh inter-unit conductive electrode 400C-7 is provided on the third side surface (left side surface), and electrically connects the fourth connection pad 160-4 of the first liquid crystal unit 100C-1 and the third connection pad 160-3 of the fourth liquid crystal unit 100C-4 to the seventh terminal 210-7 on the second terminal connection substrate 200C-2. The eighth inter-unit conductive electrode 400C-8 is provided on the third side surface (left side surface) and electrically connects the third connection pad 160-3 of the first liquid crystal unit 100C-1 and the fourth connection pad 160-4 of the fourth liquid crystal unit 100C-4 to the eighth terminal 210-8 on the second terminal connection substrate 200C-2.

[0159] In the optical element 10C including the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 having the above-mentioned orientation direction, the diffusion of the S polarization component of the light can be controlled by the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4, and the diffusion of the P polarization component of the light can be controlled by the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3.

[0160] Therefore, in the optical element 10C, by simply inputting a signal to one terminal 210 , a voltage corresponding to the signal can be simultaneously applied to two transparent electrodes 120 included in two different liquid crystal cells 100C.

[0161] Specifically, if Figure 20G As shown, the first signal S1 input to the first terminal 210-1 is input to the third transparent electrode 120-3 of the second liquid crystal cell 100C-2 and the fourth transparent electrode 120-4 of the third liquid crystal cell 100C-3 via the first inter-cell conduction electrode 400C-1. The second signal S2 input to the second terminal 210-2 is input to the fourth transparent electrode 120-4 of the second liquid crystal cell 100C-2 and the third transparent electrode 120-3 of the third liquid crystal cell 100C-3 via the second inter-cell conduction electrode 400C-2. The third signal S3 input to the third terminal 210-3 is input to the first transparent electrode 120-1 of the second liquid crystal cell 100C-2 and the second transparent electrode 120-2 of the third liquid crystal cell 100C-3 via the third inter-cell conduction electrode 400C-3. The fourth signal S4 input to the fourth terminal 210-4 is input to the second transparent electrode 120-2 of the second liquid crystal cell 100C-2 and the first transparent electrode 120-1 of the third liquid crystal cell 100C-3 via the fourth inter-cell conduction electrode 400C-4. The fifth signal S5 input to the fifth terminal 210-5 is input to the second transparent electrode 120-2 of the first liquid crystal cell 100C-1 and the first transparent electrode 120-1 of the fourth liquid crystal cell 100C-4 via the fifth inter-cell conduction electrode 400C-5. The sixth signal S6 input to the sixth terminal 210-6 is input to the first transparent electrode 120-1 of the first liquid crystal cell 100C-1 and the second transparent electrode 120-2 of the fourth liquid crystal cell 100C-4 via the sixth inter-cell conduction electrode 400C-6. The seventh signal S7 input to the seventh terminal 210-7 is input to the fourth transparent electrode 120-4 of the first liquid crystal cell 100C-1 and the third transparent electrode 120-3 of the fourth liquid crystal cell 100C-4 via the seventh inter-cell conduction electrode 400C-7. The eighth signal S8 input to the eighth terminal 210-8 is input to the third transparent electrode 120-3 of the first liquid crystal cell 100C-1 and the fourth transparent electrode 120-4 of the fourth liquid crystal cell 100C-4 via the eighth inter-cell conduction electrode 400C-8.

[0162] [2. Light distribution control of optical element 10C]

[0163] In the electrical connection in the optical element 10C, it is also possible to control the light distribution to have a different shape. Next, the control of the light distribution in the optical element 10C will be described.

[0164] [2-1. Line shape extending toward the x-axis direction]

[0165] Fig.21 1 is a timing chart showing signals input to the optical element 10C in order to control the linear light distribution in the x-axis direction in the present embodiment.

[0166] like Fig.21 As shown, the third signal S3, the fourth signal S4, the seventh signal S7 and the eighth signal S8 each have an AC rectangular wave in which high voltage and low voltage are alternately repeated. However, the phases of the third signal S3 and the fourth signal S4 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In addition, the first signal S1, the second signal S2, the fifth signal S5 and the sixth signal S6 are 0V, respectively. In this case, a lateral electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the third signal S3 and the fourth signal S4. Therefore, the P-polarized component of the light emitted from the light source 20 is diffused only in the x-axis direction in the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3. In addition, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of each of the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4 by the seventh signal S7 and the eighth signal S8. Therefore, the S-polarized component of the light emitted from the light source 20 is diffused only in the x-axis direction in the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4. Therefore, the light in any of the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 is diffused in the x-axis direction, so the light passing through the optical element 10C has a linear shape extending toward the x-axis direction. In addition, the diffusion width in the x-axis direction (the light distribution angle in the x-axis direction) can be controlled by adjusting the potential difference between the high potential and the low potential. For example, when the potential difference becomes larger, the diffusion width in the x-axis direction becomes larger.

[0167] [2-2. Line shape extending toward the y-axis direction]

[0168] Fig. 22 1 is a timing chart showing signals input to the optical element 10C in order to control the linear light distribution in the y-axis direction in the present embodiment.

[0169] like Fig. 22 As shown, the first signal S1, the second signal S2, the fifth signal S5 and the sixth signal S6 each have an AC rectangular wave in which high voltage and low voltage are alternately repeated. However, the phases of the first signal S1 and the second signal S2 are reversed, and the phases of the fifth signal S5 and the sixth signal S6 are reversed. In addition, the third signal S3, the fourth signal S4, the seventh signal S7 and the eighth signal S8 are 0V respectively. In this case, a lateral electric field in the y-axis direction is generated between the third transparent electrode 120C-3 and the fourth transparent electrode 120C-4 of each of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the first signal S1 and the second signal S2. Therefore, the P-polarized component of the light emitted from the light source 20 is diffused only in the y-axis direction in the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of each of the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4 by the fifth signal S5 and the sixth signal S6. Therefore, the S-polarized component of the light emitted from the light source 20 is diffused only in the y-axis direction in the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4. Therefore, the light in any of the first liquid crystal unit 100C-1 to the fourth liquid crystal unit 100C-4 is diffused in the y-axis direction, so the light passing through the optical element 10C has a linear shape extending toward the y-axis direction. In addition, the diffusion width in the y-axis direction (the light distribution angle in the y-axis direction) can be controlled by adjusting the potential difference between the high potential and the low potential. For example, when the potential difference becomes larger, the diffusion width in the y-axis direction becomes larger.

[0170] [2-3.Circle]

[0171] Fig.23 1 is a timing chart showing signals input to the optical element 10C in order to control light distribution having a circular shape in the present embodiment.

[0172] like Fig.23As shown, the first signal S1 to the eighth signal S8 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the first signal S1 and the second signal are reversed, the phases of the third signal S3 and the fourth signal S4 are reversed, the phases of the fifth signal S5 and the sixth signal S6 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In this case, a lateral electric field in the y-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of each of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the first signal S1 and the second signal S2. Furthermore, a lateral electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of each of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the third signal S3 and the fourth signal S4. Therefore, the P polarization component of the light emitted from the light source 20 is diffused not only in the x-axis direction but also in the y-axis direction in the second liquid crystal cell 100C-2 and the third liquid crystal cell 100C-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of each of the first liquid crystal cell 100C-1 and the fourth liquid crystal cell 100C-4 by the fifth signal S5 and the sixth signal S6. Furthermore, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of each of the first liquid crystal cell 100C-1 and the fourth liquid crystal cell 100C-4 by the seventh signal S7 and the eighth signal S8. Therefore, the S polarization component of the light emitted from the light source 20 is diffused not only in the x-axis direction but also in the y-axis direction in the first liquid crystal cell 100C-1 and the fourth liquid crystal cell 100C-4. Therefore, light is diffused in the x-axis direction and the y-axis direction in any of the first liquid crystal cell 100C-1 to the fourth liquid crystal cell 100C-4, and thus light transmitted through the optical element 10 has a circular shape extending in the x-axis direction and the y-axis direction.

[0173] [2-4. Elliptical shape]

[0174] Fig.24 1 is a timing chart showing signals input to the optical element 10C in order to control the light distribution having an elliptical shape in the present embodiment.

[0175] Fig.24 The timing diagram shown is similar to Fig.23 The timing diagrams shown are substantially the same, but the voltage amplitudes of the first signal S1 to the eighth signal S8 are different. Fig.24As shown, the amplitude a of the third signal S3, the fourth signal S4, the seventh signal S7 and the eighth signal S8 is different from the amplitude b of the first signal S1, the second signal S2, the fifth signal S5 and the sixth signal S6. The diffusion in the x-axis direction and the y-axis direction corresponds to the amplitude a and the amplitude b, respectively. Therefore, in the case of a>b, the light passing through the optical element 10 diffuses more in the x-axis direction than in the y-axis direction, and has an elliptical shape with a major axis in the x-axis direction. On the other hand, in the case of a<b, the light passing through the optical element 10 diffuses more in the y-axis direction than in the x-axis direction, and has an elliptical shape with a major axis in the y-axis direction.

[0176] [2-5. Cross shape]

[0177] Fig.25 1 is a timing chart showing signals input to the optical element 10C in order to control light distribution having a cross shape in the present embodiment.

[0178] like Fig.25 As shown, the first signal S1, the second signal S2, the seventh signal S7 and the eighth signal S8 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the first signal S1 and the second signal S2 are reversed, and the phases of the seventh signal S7 and the eighth signal S8 are reversed. In addition, the third signal S3 to the sixth signal S6 are 0V respectively. In this case, a transverse electric field in the y-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the first signal S1 and the second signal S2. Therefore, the P polarization component of the light emitted from the light source 20 is diffused only in the y-axis direction in the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3. In addition, a transverse electric field in the x-axis direction is generated between the third transparent electrode 120-3 and the fourth transparent electrode 120-4 of the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4 by the seventh signal S7 and the eighth signal S8. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4. Therefore, the P polarization component and the S polarization component are diffused only in one direction of the x-axis direction and the y-axis direction, respectively, so that the light transmitted through the optical element 10 has a cross shape that selectively expands in the x-axis direction and the y-axis direction. In addition, the diffusion width in the x-axis direction (light distribution angle in the x-axis direction) and the diffusion width in the y-axis direction (light distribution angle in the y-axis direction) can be controlled by adjusting the amplitude a and the amplitude b, respectively.

[0179] In addition, the timing chart for controlling the light distribution having a cross shape is not limited to Fig.25The following is the timing diagram. Fig.26 , a modified example of a timing diagram for controlling a light distribution having a cross shape is described.

[0180] Fig.26 1 is another timing chart showing signals input to the optical element 10C in order to control the light distribution having a cross shape in the present embodiment.

[0181] like Fig.26 As shown, the third signal S3 to the sixth signal S6 each have an alternating rectangular wave in which high voltage and low voltage are repeated alternately. However, the phases of the third signal S3 and the fourth signal S4 are reversed, and the phases of the fifth signal S5 and the sixth signal S6 are reversed. In addition, the first signal S1, the second signal S2, the seventh signal S7, and the eighth signal S8 are 0V, respectively. In this case, a transverse electric field in the x-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3 by the third signal S3 and the fourth signal S4. Therefore, the P polarization component of the light emitted from the light source 20 is diffused only in the x-axis direction in the second liquid crystal unit 100C-2 and the third liquid crystal unit 100C-3. In addition, a transverse electric field in the y-axis direction is generated between the first transparent electrode 120-1 and the second transparent electrode 120-2 of the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4 by the fifth signal S5 and the sixth signal S6. Therefore, the S polarization component of the light emitted from the light source 20 is diffused only in the y-axis direction in the first liquid crystal unit 100C-1 and the fourth liquid crystal unit 100C-4. Therefore, the P polarization component and the S polarization component are diffused only in one direction of the x-axis direction and the y-axis direction, respectively, so that the light transmitted through the optical element 10C has a cross shape that selectively expands in the x-axis direction and the y-axis direction. In addition, the diffusion width in the x-axis direction (light distribution angle in the x-axis direction) and the diffusion width in the y-axis direction (light distribution angle in the y-axis direction) can be controlled by adjusting the amplitude b and the amplitude a, respectively.

[0182] As described above, in this embodiment, the arrangement direction of the liquid crystal unit 100 described in the first embodiment can be changed to manufacture an optical element 10C different from the optical element 10. In the optical element 10C, it is also possible to control the light distribution by applying a voltage to a plurality of transparent electrodes 120 included in a plurality of liquid crystal units 100C at the same time through the inter-unit conductive electrode 400C provided on the side of the optical element 10C. Therefore, the number of signals input to the optical element 10C can be reduced, so the control of the light distribution of the optical element 10C is simplified. Furthermore, since the number of terminals 210 electrically connected to the transparent electrode 120 is reduced, the wiring connection in the mounting process is simplified, and the manufacturing yield of the optical element 10C is improved. In addition, the lighting device 1C including the optical element 10C is also excellent in the control of light distribution, and the manufacturing yield is improved.

[0183] Within the scope of the concept of the present invention, as long as a person skilled in the art can think of various variations and modifications, these variations and modifications are also understood to belong to the scope of the present invention. For example, for each of the above-mentioned embodiments, a person skilled in the art appropriately adds, deletes or changes the design of the constituent elements, or adds, omits or changes the conditions of the processes, as long as they have the gist of the present invention, they are also included in the scope of the present invention.

[0184] In addition, regarding other effects brought about by the aspects in the present embodiment, those that are clear from the description of this specification or that can be appropriately imagined by a person skilled in the art are naturally understood to be effects brought about by the present invention.

[0185] Description of Reference Numerals

[0186] 1, 1A, 1B, 1C: lighting device; 10, 10A, 10B, 10C: optical element; 20: light source; 100, 100B, 100C: liquid crystal unit; 110: substrate; 120: transparent electrode; 130: orientation film; 140: sealing material; 150: liquid crystal layer; 160: connecting pad; 200, 200A, 200B, 200C: terminal connection substrate; 210, 210A: terminal; 300: optical elastic resin layer; 400, 400A, 400B, 400C: inter-unit conductive electrode; 1000-1: first light; 1000-2: second light.

Claims

1. An optical element, comprising a first liquid crystal unit, a second liquid crystal unit, a third liquid crystal unit and a fourth liquid crystal unit stacked in sequence, The first liquid crystal unit, the second liquid crystal unit, the third liquid crystal unit and the fourth liquid crystal unit each include: A first substrate is provided with a first electrode, a second electrode, a first connection pad electrically connected to the first electrode, and a second connection pad electrically connected to the second electrode; a second substrate provided with a third electrode, a fourth electrode, a third connection pad electrically connected to the third electrode, and a fourth connection pad electrically connected to the fourth electrode; and A liquid crystal layer between the first substrate and the second substrate, The second substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, The first substrate of the third liquid crystal unit is opposite to the first substrate of the second liquid crystal unit. The second substrate of the fourth liquid crystal unit is opposite to the second substrate of the third liquid crystal unit. The first connection pad of the first liquid crystal unit is electrically connected to the first connection pad of the third liquid crystal unit via a first inter-unit conductive electrode. The second connection pad of the first liquid crystal unit is electrically connected to the second connection pad of the third liquid crystal unit via a second inter-unit conductive electrode. The third connection pad of the first liquid crystal unit is electrically connected to the third connection pad of the third liquid crystal unit via a third inter-unit conductive electrode. The fourth connection pad of the first liquid crystal unit is electrically connected to the fourth connection pad of the third liquid crystal unit via a fourth inter-unit conductive electrode. The first connection pad of the second liquid crystal unit is electrically connected to the first connection pad of the fourth liquid crystal unit via a fifth inter-unit conductive electrode. The second connection pad of the second liquid crystal unit is electrically connected to the second connection pad of the fourth liquid crystal unit via a sixth inter-unit conductive electrode. The third connection pad of the second liquid crystal unit is electrically connected to the third connection pad of the fourth liquid crystal unit via a seventh inter-unit conductive electrode. The fourth connection pad of the second liquid crystal cell is electrically connected to the fourth connection pad of the fourth liquid crystal cell via an eighth inter-cell conduction electrode.

2. An optical element, comprising a first liquid crystal unit, a second liquid crystal unit, a third liquid crystal unit and a fourth liquid crystal unit stacked in sequence, The first liquid crystal unit, the second liquid crystal unit, the third liquid crystal unit and the fourth liquid crystal unit each include: A first substrate is provided with a first electrode, a second electrode, a first connection pad electrically connected to the first electrode, and a second connection pad electrically connected to the second electrode; a second substrate provided with a third electrode, a fourth electrode, a third connection pad electrically connected to the third electrode, and a fourth connection pad electrically connected to the fourth electrode; and A liquid crystal layer between the first substrate and the second substrate, The second substrate of the second liquid crystal unit is opposite to the second substrate of the first liquid crystal unit, The first substrate of the third liquid crystal unit is opposite to the first substrate of the second liquid crystal unit. The second substrate of the fourth liquid crystal unit is opposite to the second substrate of the third liquid crystal unit. The third connection pad of the second liquid crystal unit is electrically connected to the first connection pad of the third liquid crystal unit via the first inter-unit conductive electrode. The fourth connection pad of the second liquid crystal unit is electrically connected to the second connection pad of the third liquid crystal unit via a second inter-unit conductive electrode. The first connection pad of the second liquid crystal unit is electrically connected to the third connection pad of the third liquid crystal unit via a third inter-unit conductive electrode. The second connection pad of the second liquid crystal unit is electrically connected to the fourth connection pad of the third liquid crystal unit via a fourth inter-unit conductive electrode. The second connection pad of the first liquid crystal unit is electrically connected to the first connection pad of the fourth liquid crystal unit via a fifth inter-unit conductive electrode. The first connection pad of the first liquid crystal unit is electrically connected to the second connection pad of the fourth liquid crystal unit via a sixth inter-unit conductive electrode. The fourth connection pad of the first liquid crystal unit is electrically connected to the third connection pad of the fourth liquid crystal unit via a seventh inter-unit conductive electrode. The third connection pad of the first liquid crystal cell is electrically connected to the fourth connection pad of the fourth liquid crystal cell via an eighth inter-cell conduction electrode.

3. The optical element according to claim 1 or 2, wherein: When viewed from above, at least a portion of the first connection pad and at least a portion of the second connection pad are exposed from the second substrate. In the plan view, at least a portion of the third connection pad and at least a portion of the fourth connection pad are exposed from the first substrate.

4. The optical element according to claim 1 or 2, wherein: When viewed from above, the first liquid crystal cell, the second liquid crystal cell, the third liquid crystal cell, and the fourth liquid crystal cell are respectively substantially square or substantially rectangular.

5. The optical element according to claim 1 or 2, wherein: The optical element further comprises: A first terminal connection substrate is disposed adjacent to the first liquid crystal unit and is provided with a first terminal, a second terminal, a third terminal and a fourth terminal; and The second terminal is connected to the substrate, is arranged adjacent to the fourth liquid crystal unit, and is provided with a fifth terminal, a sixth terminal, a seventh terminal and an eighth terminal. The first inter-cell conducting electrode, the second inter-cell conducting electrode, the third inter-cell conducting electrode, and the fourth inter-cell conducting electrode are electrically connected to the first terminal, the second terminal, the third terminal, and the fourth terminal, respectively. The fifth inter-cell conduction electrode, the sixth inter-cell conduction electrode, the seventh inter-cell conduction electrode, and the eighth inter-cell conduction electrode are electrically connected to the fifth terminal, the sixth terminal, the seventh terminal, and the eighth terminal, respectively.

6. The optical element according to claim 1 or 2, wherein: The optical element further includes a terminal connection substrate, which is arranged adjacent to one of the first liquid crystal unit and the fourth liquid crystal unit and is provided with a first terminal, a second terminal, a third terminal, a fourth terminal, a fifth terminal, a sixth terminal, a seventh terminal and an eighth terminal. The first inter-unit conductive electrode, the second inter-unit conductive electrode, the third inter-unit conductive electrode, the fourth inter-unit conductive electrode, the fifth inter-unit conductive electrode, the sixth inter-unit conductive electrode, the seventh inter-unit conductive electrode and the eighth inter-unit conductive electrode are electrically connected to the first terminal, the second terminal, the third terminal, the fourth terminal, the fifth terminal, the sixth terminal, the seventh terminal and the eighth terminal, respectively.

7. A lighting device, comprising: The optical element according to claim 1 or 2; as well as The light source is arranged adjacent to the first liquid crystal unit.

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