Optical device

Abstract

An optical device includes: an optical element including at least one liquid crystal cell that performs light distribution on light irradiated from a light source; a power supply section that generates a first potential and a second potential different from the first potential; a control signal generation circuit section that generates a control signal that controls a pulse width of each of the first potential and the second potential; and a switching circuit section that outputs, based on the control signal, a first potential signal including the first potential having a first pulse width and the second potential having a second pulse width, the at least one liquid crystal cell including: a first substrate alternately provided with a first transparent electrode and a second transparent electrode in a first direction; and a second substrate alternately provided with a third transparent electrode and a fourth transparent electrode in a second direction intersecting the first direction, the first potential signal being input to the first transparent electrode.

Description

Technical Field

[0001] One embodiment of the present invention relates to an optical device for controlling the light distribution of light emitted from a light source, and more particularly to an optical device using liquid crystal. Background Technology

[0002] Previously, optical elements that utilize changes in the refractive index of a liquid crystal to adjust the voltage applied to it, known as liquid crystal lenses (see, for example, Patent Document 1, Patent Document 2, or Patent Document 3). For example, the illumination devices described in Patent Document 1 and Patent Document 2 use liquid crystal lenses to distribute light from a light source into a circular shape. Furthermore, in the beam shaping device described in Patent Document 3, the shape of the light distribution is changed by altering the pattern of the electrodes applied to the liquid crystal.

[0003] Existing technical documents

[0004] Patent documents

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

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

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

[0008] The problem that the invention aims to solve

[0009] In optical devices using liquid crystals, light distribution is sometimes controlled by varying the voltage applied to the liquid crystal. In this case, the optical device needs to have a digital-to-analog converter (DAC) or amplifier (AMP) circuit, which becomes a major reason for the increased complexity of light distribution control and the increased manufacturing cost.

[0010] In view of the above-mentioned problems, one of the objectives of this invention is to provide an optical device that reduces manufacturing costs.

[0011] Technical solutions for solving the problem

[0012] An optical device according to one embodiment of the present invention includes: an optical element comprising at least one liquid crystal cell for distributing light irradiated from a light source; a power supply unit for generating a first potential and a second potential different from the first potential; a control signal generation circuit unit for generating a control signal for controlling the pulse width of the first potential and the second potential respectively; and a switching circuit unit for outputting a first potential signal based on the control signal, the first potential signal including a first potential having a first pulse width and a second potential having a second pulse width, wherein the at least one liquid crystal cell includes: a first substrate having a first transparent electrode and a second transparent electrode alternately disposed in a first direction; and a second substrate having a third transparent electrode and a fourth transparent electrode alternately disposed in a second direction intersecting the first direction, wherein the first potential signal is input to the first transparent electrode.

[0013] Furthermore, one embodiment of the optical device according to the present invention includes: an optical element comprising at least one liquid crystal cell for distributing light irradiated from a light source; a power supply unit comprising a first power supply for generating a first potential and a second power supply for generating a second potential different from the first potential; a control signal generation unit for generating a first control signal, a second control signal, a third control signal, and a fourth control signal for controlling the pulse widths of the first potential and the second potential respectively; and a switching circuit unit electrically connected to the first power supply and the second power supply respectively, comprising a first switching circuit that outputs a first potential signal based on the first control signal, a second switching circuit that outputs a second potential signal based on the second control signal, and a third switching circuit that outputs a third potential signal based on the third control signal. The optical element includes at least one liquid crystal unit, which includes: a first substrate, wherein a first transparent electrode and a second transparent electrode are alternately arranged in a first direction; and a second substrate, wherein a third transparent electrode and a fourth transparent electrode are alternately arranged in a second direction intersecting the first direction. The first transparent electrode, the second transparent electrode, the third transparent electrode and the fourth transparent electrode are electrically connected to the first switch circuit, the second switch circuit, the third switch circuit and the fourth switch circuit, respectively, and the first potential signal, the second potential signal, the third potential signal and the fourth potential signal are respectively input to the first transparent electrode, the second transparent electrode, the third transparent electrode and the fourth transparent electrode. Attached Figure Description

[0014] Figure 1A This is a schematic perspective view of an optical device according to one embodiment of the present invention.

[0015] Figure 1B This is a diagram illustrating an optical device according to one embodiment of the present invention.

[0016] Figure 2 This is a schematic perspective view of the optical elements of an optical device according to one embodiment of the present invention.

[0017] Figure 3A This is a schematic cross-sectional view of an optical element of an optical device according to one embodiment of the present invention.

[0018] Figure 3B This is a schematic cross-sectional view of an optical element of an optical device according to one embodiment of the present invention.

[0019] Figure 4A This is a schematic cross-sectional view illustrating the control of light distribution by optical elements of an optical device according to one embodiment of the present invention.

[0020] Figure 4B This is a schematic cross-sectional view illustrating the control of light distribution by optical elements of an optical device according to one embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram illustrating the connection between the transparent electrode of the optical element and the switching circuit section in an optical device according to one embodiment of the present invention.

[0022] Figure 6 This is a circuit diagram showing the switching circuit included in the switching circuit section of an optical device according to one embodiment of the present invention.

[0023] Figure 7A This is a timing diagram illustrating the relationship between the control signal input to the switching circuit section and the potential signal output from the switching circuit section in an optical device according to one embodiment of the present invention.

[0024] Figure 7B This is a timing diagram illustrating the relationship between the control signal input to the switching circuit section and the potential signal output from the switching circuit section in an optical device according to one embodiment of the present invention.

[0025] Figure 8 This is a timing diagram showing the relationship between a potential signal and a potential difference between a transparent electrode in an optical device according to one embodiment of the present invention.

[0026] Figure 9 This is a timing diagram showing the relationship between a potential signal and a potential difference between a transparent electrode in an optical device according to one embodiment of the present invention.

[0027] Figure 10 This is a timing diagram showing the relationship between a potential signal and a potential difference between a transparent electrode in an optical device according to one embodiment of the present invention.

[0028] Figure 11 It is a graph showing the light distribution state of an optical device using an embodiment of the present invention. Detailed Implementation

[0029] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings, etc. Furthermore, the present invention can be implemented in various ways without departing from its technical spirit and is not limited to the descriptions of the embodiments illustrated below.

[0030] To make the description clearer, the accompanying drawings sometimes schematically represent the width, thickness, shape, etc. of various parts compared to the actual representation. However, these are merely examples, and the shapes shown in the drawings do not limit the interpretation of the invention. Furthermore, in the accompanying drawings, elements having the same function as those described in the figures already presented in the specification are also labeled with the same symbols in other figures, sometimes omitting repeated descriptions.

[0031] When processing a single membrane to form multiple structures, these structures may have different functions and roles, and sometimes they may be formed from different substrates. However, these multiple structures originate from a membrane formed as the same layer in the same process and are made of the same material. Therefore, they are defined as existing within the same layer.

[0032] When describing the way in which other structures are placed on top of a certain structure, if only described as "above", unless otherwise specified, it includes two cases: placing other structures directly above a certain structure, and placing other structures above a certain structure with another structure in between.

[0033] Reference Figures 1A to 11 The optical device 1 according to one embodiment of the present invention will be described first. Referring to… Figure 1A as well as Figure 1B The structure of optical device 1 will be described.

[0034] [1. Structure of optical device 1]

[0035] Figure 1A This is a schematic perspective view of an optical device 1 according to one embodiment of the present invention. Additionally, Figure 1B This is a block diagram illustrating an optical device 1 according to one embodiment of the present invention. Figure 1AAs shown, the optical device 1 includes an optical element 10 and a control unit 20 for controlling the optical element 10. Furthermore, in addition to the optical element 10 and the control unit 20, the optical device 1 may also include a light source 30 that illuminates the optical element 10. Light illuminated from the light source 30 passes through the optical element 10 and exits. The control unit 20 controls the optical element 10, causing the light passing through the optical element 10 to diffuse or converge. That is, the optical device 1 can control the light distribution.

[0036] like Figure 1B As shown, the control unit 20 includes a power supply unit 210, a switching circuit unit 220, and a control signal generation circuit unit 230. The optical element 10 is connected to the switching circuit unit 220. Furthermore, the switching circuit unit 220 is connected to the power supply unit 210. That is, the optical element 10 is connected to the power supply unit 210 via the switching circuit unit 220.

[0037] The power supply unit 210 includes a power source that generates a predetermined potential. For example, the power supply unit 210 may include two power sources that generate two potentials, but is not limited to this. Additionally, the power supply unit 210 may include a potential as GND (e.g., 0V). It should be noted that, for ease of explanation in this specification, even in the case of GND, it is sometimes described as a power source that generates a potential.

[0038] The control signal generation circuit 230 generates control signals for the control switch circuit 220. Multiple control signals for the control switch circuits 220 can also be generated. The switch circuit included in the switch circuit 220 is a so-called analog switch. That is, the switch circuit 220 can control the supply of potential generated by the power supply unit 210 to the optical element 10 based on the control signals from the control signal generation circuit 230. In the optical device 1, since the supply of potential generated by the power supply unit 210 is directly controlled by the switch circuit 220, the optical device 1 does not require a DAC or AMP.

[0039] The control signal generation circuit unit 230 is a computer capable of performing calculations and processing using data or information. The control signal generation circuit unit 230 may include, for example, a central processing unit (CPU), a microprocessor (MPU), a graphics processing unit (GPU), a field-programmable gate array (FPGA), random access memory (RAM), or dynamic random access memory (DRAM). The control signal generation circuit unit 230 can generate control signals based on predetermined information (pulse width or duty cycle, etc.).

[0040] Next, refer to Figures 2-3B The structure of the optical element 10 will be explained.

[0041] [2. Structure of optical element 10]

[0042] Figure 2 This is a schematic perspective view of the optical element 10 of the optical device 1 according to one embodiment of the present invention. Figure 2 As shown, the optical element 10 includes a first liquid crystal unit 110-1, a second liquid crystal unit 110-2, a third liquid crystal unit 110-3, and a fourth liquid crystal unit 110-4. The first liquid crystal unit 110-1, the second liquid crystal unit 110-2, the third liquid crystal unit 110-3, and the fourth liquid crystal unit 110-4 are stacked along the z-axis. The second liquid crystal unit 110-2 is disposed on the first liquid crystal unit 110-1. The third liquid crystal unit 110-3 is disposed on the second liquid crystal unit 110-2. The fourth liquid crystal unit 110-4 is disposed on the third liquid crystal unit 110-3. Although not shown, the light source 30 is positioned below the first liquid crystal unit 110-1. Therefore, light irradiated by the light source 30 passes sequentially through the first liquid crystal unit 110-1, the second liquid crystal unit 110-2, the third liquid crystal unit 110-3, and the fourth liquid crystal unit 110-4.

[0043] The first optically elastic resin layer 170-1 bonds and fixes the first liquid crystal unit 110-1 and the second liquid crystal unit 110-2. The second optically elastic resin layer 170-2 bonds and fixes the second liquid crystal unit 110-2 and the third liquid crystal unit 110-3. The third optically elastic resin layer 170-3 bonds and fixes the third liquid crystal unit 110-3 and the fourth liquid crystal unit 110-4. As each resin layer of the first optically elastic resin layer 170-1, the second optically elastic resin layer 170-2, and the third optically elastic resin layer 170-3, an adhesive containing a light-transmitting acrylic resin or epoxy resin can be used.

[0044] Figure 3A as well as Figure 3B This is a schematic cross-sectional view of the optical element 10 of the optical device 1 according to one embodiment of the present invention. Specifically, Figure 3A It is along Figure 2 The schematic cross-sectional view shown is taken within the zx plane cut by line A1-A2. Figure 3B It is along Figure 2 The diagram shows a schematic cross-sectional view in the yz plane cut by line B1-B2. It should be noted that, hereinafter, the x-axis direction and y-axis direction will sometimes be referred to as the first direction and the second direction, respectively.

[0045] The first liquid crystal unit 110-1 includes a first substrate 120-1 on which a first transparent electrode 130-1 and a second transparent electrode 130-2 are formed, and a second substrate 120-2 on which a third transparent electrode 130-3 and a fourth transparent electrode 130-4 are formed. A first alignment film 140-1 covering the first transparent electrode 130-1 and the second transparent electrode 130-2 is formed on the first substrate 120-1. A second alignment film 140-2 covering the third transparent electrode 130-3 and the fourth transparent electrode 130-4 is formed on the second substrate 120-2. The first substrate 120-1 and the second substrate 120-2 are arranged such that the first transparent electrode 130-1 and the second transparent electrode 130-2 on the first substrate 120-1 are opposite to the third transparent electrode 130-3 and the fourth transparent electrode 130-4 on the second substrate 120-2 in a crosswise (hereinafter the same) manner. Furthermore, a first sealing material 150-1 is formed at the periphery of both the first substrate 120-1 and the second substrate 120-2. That is, the first substrate 120-1 and the second substrate 120-2 are bonded together via the first sealing material 150-1. In addition, liquid crystal is sealed in the space surrounded by the first substrate 120-1 (more specifically, the first alignment film 140-1), the second substrate 120-2 (more specifically, the second alignment film 140-2), and the first sealing material 150-1 to form a first liquid crystal layer 160-1.

[0046] The second liquid crystal unit 110-2 includes a third substrate 120-3 on which a fifth transparent electrode 130-5 and a sixth transparent electrode 130-6 are formed, and a fourth substrate 120-4 on which a seventh transparent electrode 130-7 and an eighth transparent electrode 130-8 are formed. A third alignment film 140-3 covering the fifth transparent electrode 130-5 and the sixth transparent electrode 130-6 is formed on the third substrate 120-3. A fourth alignment film 140-4 covering the seventh transparent electrode 130-7 and the eighth transparent electrode 130-8 is formed on the fourth substrate 120-4. The third substrate 120-3 and the fourth substrate 120-4 are arranged such that the fifth transparent electrode 130-5 and the sixth transparent electrode 130-6 on the third substrate 120-3 are opposite to the seventh transparent electrode 130-7 and the eighth transparent electrode 130-8 on the fourth substrate 120-4. Furthermore, a second sealing material 150-2 is formed on the periphery of both the third substrate 120-3 and the fourth substrate 120-4. That is, the third substrate 120-3 and the fourth substrate 120-4 are bonded together via the second sealing material 150-2. In addition, liquid crystal is sealed into the space surrounded by the third substrate 120-3 (more specifically, the third alignment film 140-3), the fourth substrate 120-4 (more specifically, the fourth alignment film 140-4), and the second sealing material 150-2 to form a second liquid crystal layer 160-2.

[0047] The third liquid crystal unit 110-3 includes a fifth substrate 120-5 on which a ninth transparent electrode 130-9 and a tenth transparent electrode 130-10 are formed, and a sixth substrate 120-6 on which an eleventh transparent electrode 130-11 and a twelfth transparent electrode 130-12 are formed. A fifth alignment film 140-5 covering the ninth transparent electrode 130-9 and the tenth transparent electrode 130-10 is formed on the fifth substrate 120-5. A sixth alignment film 140-6 covering the eleventh transparent electrode 130-11 and the twelfth transparent electrode 130-12 is formed on the sixth substrate 120-6. The fifth substrate 120-5 and the sixth substrate 120-6 are arranged such that the ninth transparent electrode 130-9 and the tenth transparent electrode 130-10 on the fifth substrate 120-5 are opposite to the eleventh transparent electrode 130-11 and the twelfth transparent electrode 130-12 on the sixth substrate 120-6. Furthermore, a third sealing material 150-3 is formed on the periphery of both the fifth substrate 120-5 and the sixth substrate 120-6. That is, the fifth substrate 120-5 and the sixth substrate 120-6 are bonded together via the third sealing material 150-3. In addition, liquid crystal is sealed into the space surrounded by the fifth substrate 120-5 (more specifically, the fifth alignment film 140-5), the sixth substrate 120-6 (more specifically, the sixth alignment film 140-6), and the third sealing material 150-3 to form a third liquid crystal layer 160-3.

[0048] The fourth liquid crystal unit 110-4 includes a seventh substrate 120-7 on which a thirteenth transparent electrode 130-13 and a fourteenth transparent electrode 130-14 are formed, and an eighth substrate 120-8 on which a fifteenth transparent electrode 130-15 and a sixteenth transparent electrode 130-16 are formed. A seventh alignment film 140-7 covering the thirteenth transparent electrode 130-13 and the fourteenth transparent electrode 130-14 is formed on the seventh substrate 120-7. An eighth alignment film 140-8 covering the fifteenth transparent electrode 130-15 and the sixteenth transparent electrode 130-16 is formed on the eighth substrate 120-8. The seventh substrate 120-7 and the eighth substrate 120-8 are arranged such that the thirteenth transparent electrode 130-13 and the fourteenth transparent electrode 130-14 on the seventh substrate 120-7 are opposite to the fifteenth transparent electrode 130-15 and the sixteenth transparent electrode 130-16 on the eighth substrate 120-8. Furthermore, a fourth sealing material 150-4 is formed on the periphery of both the seventh substrate 120-7 and the eighth substrate 120-8. That is, the seventh substrate 120-7 and the eighth substrate 120-8 are bonded together via the fourth sealing material 150-4. In addition, liquid crystal is sealed into the space surrounded by the seventh substrate 120-7 (more specifically, the seventh alignment film 140-7), the eighth substrate 120-8 (more specifically, the eighth alignment film 140-8), and the fourth sealing material 150-4 to form a fourth liquid crystal layer 160-4.

[0049] The basic structures of the first liquid crystal unit 110-1, the second liquid crystal unit 110-2, the third liquid crystal unit 110-3, and the fourth liquid crystal unit 110-4 are the same. Therefore, the configuration of the transparent electrode 130 of the first liquid crystal unit 110-1 will be described below, while the configuration of the transparent electrodes 130 of the second liquid crystal unit 110-2, the third liquid crystal unit 110-3, and the fourth liquid crystal unit 110-4 will be omitted.

[0050] In the first liquid crystal cell 110-1, the first transparent electrode 130-1 and the second transparent electrode 130-2 extend in the y-axis direction, and the third transparent electrode 130-3 and the fourth transparent electrode 130-4 extend in the x-axis direction. Furthermore, the first transparent electrode 130-1 and the second transparent electrode 130-2 are alternately arranged in a comb-like pattern in the x-axis direction, and the third transparent electrode 130-3 and the fourth transparent electrode 130-4 are alternately arranged in a comb-like pattern in the second direction. When viewed from above, the extending directions (y-axis direction) of the first transparent electrode 130-1 and the second transparent electrode 130-2 are orthogonal to the extending directions (x-axis direction) of the third transparent electrode 130-3 and the fourth transparent electrode 130-4, but they may also intersect slightly off-orthogonally.

[0051] When viewed from above, the first transparent electrode 130-1 of the first liquid crystal unit 110-1, the fifth transparent electrode 130-5 of the second liquid crystal unit 110-2, the ninth transparent electrode 130-9 of the third liquid crystal unit 110-3, and the thirteenth transparent electrode 130-13 of the fourth liquid crystal unit 110-4 overlap in a manner that is approximately consistent with each other in the extending direction (y-axis direction). Alternatively, the first liquid crystal unit 110-1 to the fourth liquid crystal unit 110-4 may be arranged with the first transparent electrode 130-1, the fifth transparent electrode 130-5, the ninth transparent electrode 130-9, and the thirteenth transparent electrode 130-13 slightly offset and overlapping.

[0052] Each of the first substrate 120-1 to the eighth substrate 120-8 may be a rigid substrate that is transparent, such as a glass substrate, a quartz substrate, or a sapphire substrate. Alternatively, each of the first substrate 120-1 to the eighth substrate 120-8 may be a flexible substrate that is transparent, such as a polyimide resin substrate, an acrylic resin substrate, a silicone resin substrate, or a fluoropolymer resin substrate.

[0053] Each of the first transparent electrode 130-1 to the sixteenth transparent electrode 130-16 functions as an electrode for forming an electric field in the liquid crystal layer 160. Each of the first transparent electrode 130-1 to the sixteenth transparent electrode 130-16 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0054] Each of the first liquid crystal layers 160-1 to the fourth liquid crystal layer 160-4 can refract transmitted light or change the polarization state of transmitted light according to the orientation state of the liquid crystal molecules. Nematic liquid crystals, etc., are used as each of the first liquid crystal layers 160-1 to the fourth liquid crystal layer 160-4. The liquid crystal described in this embodiment is positive, but a negative structure can also be applied by changing the initial orientation direction of the liquid crystal molecules. Furthermore, it is preferable to contain a chiral agent that imparts twisting to the liquid crystal molecules.

[0055] The first alignment film 140-1 to the eighth alignment film 140-8 align liquid crystal molecules within the liquid crystal layer 160 in a predetermined direction. Each of the first alignment film 140-1 to the eighth alignment film 140-8 uses a polyimide resin or the like. It should be noted that each of the first alignment film 140-1 to the eighth alignment film 140-8 can also be given alignment characteristics through alignment treatments such as rubbing or photoalignment. Rubbing is a method of rubbing the surface of the alignment film in one direction. Photoalignment involves irradiating the alignment film with linearly polarized ultraviolet light.

[0056] Each of the materials used as the first sealing material 150-1 to the fourth sealing material 150-4 employs an adhesive material containing epoxy resin or acrylic resin. It should be noted that the adhesive material can be either UV-curable or thermosetting.

[0057] The optical element 10, by including at least two liquid crystal cells (e.g., a first liquid crystal cell 110-1 and a second liquid crystal cell 110-2), is capable of controlling the distribution of unpolarized light. Therefore, it is not necessary to provide, for example, a pair of polarizers provided on the back surface of the liquid crystal display element, on the surfaces of the first substrate 120-1 of the first liquid crystal cell 110-1 and the eighth substrate 120-8 of the fourth liquid crystal cell 110-4.

[0058] [3. Control of light distribution by optical element 10]

[0059] Figure 4A as well as Figure 4B This is a schematic cross-sectional view illustrating the control of light distribution by the optical element 10 of the optical device 1 according to one embodiment of the present invention. Figure 4A as well as Figure 4B It shows Figure 3A A portion of the cross-sectional view of the first liquid crystal unit 110-1 and the second liquid crystal unit 110-2 shown. Figure 4A The optical element 10 is shown in a state where no potential is supplied to the transparent electrode 130. Figure 4B The optical element 10 is shown in a state where a potential is supplied to the transparent electrode 130. It should be noted that the control of the potential supplied to the transparent electrode 130 will be described later.

[0060] The first alignment film 140-1 is oriented in the x-axis direction. Therefore, as... Figure 4A As shown, the long axis of the liquid crystal molecules on the first substrate 120-1 side of the first liquid crystal layer 160-1 is aligned along the x-axis direction. That is, the alignment direction of the liquid crystal molecules on the first substrate 120-1 side is orthogonal to the extending direction (y-axis direction) of the first transparent electrode 130-1 and the second transparent electrode 130-2. Furthermore, the second alignment film 140-2 is aligned in the y-axis direction. Therefore, as... Figure 3A As shown, the long axis of the liquid crystal molecules on the second substrate 120-2 side of the first liquid crystal layer 160-1 is aligned along the y-axis direction. That is, the orientation direction of the liquid crystal molecules on the second substrate 120-2 side is orthogonal to the extending direction (x-axis direction) of the third transparent electrode 130-3 and the fourth transparent electrode 130-4. Therefore, as the liquid crystal molecules of the first liquid crystal layer 160-1 move from the first substrate 120-1 toward the second substrate 120-2, the orientation of their long axis gradually changes from the x-axis direction to the y-axis direction, achieving an orientation that is twisted by 90 degrees.

[0061] The liquid crystal molecules in the second liquid crystal layer 160-2 are the same as those in the first liquid crystal layer 160-1, so the description is omitted here.

[0062] When a potential is supplied to the transparent electrode 130, such as Figure 4B As shown, the orientation of the liquid crystal molecules changes. Here, the case where a low potential is supplied to the first transparent electrode 130-1, the third transparent electrode 130-3, the fifth transparent electrode 130-5, and the seventh transparent electrode 130-7, and a high potential is supplied to the second transparent electrode 130-2, the fourth transparent electrode 130-4, the sixth transparent electrode 130-6, and the eighth transparent electrode 130-8 will be explained. It should be noted that in... Figure 4B For convenience, low potential and high potential are represented by "-" and "+" symbols, respectively. It should be noted that the electric field generated between adjacent transparent electrodes is sometimes referred to as the transverse electric field.

[0063] like Figure 4B As shown, due to the influence of the lateral electric field between the first transparent electrode 130-1 and the second transparent electrode 130-2, the liquid crystal molecules on the first substrate 120-1 side are generally oriented in a convex arc shape relative to the first substrate 120-1 along the x-axis direction. Similarly, due to the influence of the lateral electric field between the third transparent electrode 130-3 and the fourth transparent electrode 130-4, the liquid crystal molecules on the second substrate 120-2 side are generally oriented in a convex arc shape relative to the second substrate 120-2 along the y-axis direction. The orientation of the liquid crystal molecules located approximately in the center between the first transparent electrode 130-1 and the second transparent electrode 130-2 is hardly changed by any lateral electric field. Therefore, light incident on the first liquid crystal layer 160-1 diffuses in the x-axis direction according to the refractive index distribution of the liquid crystal molecules oriented in a convex arc shape along the x-axis direction on the first substrate 120-1 side, and diffuses in the y-axis direction according to the refractive index distribution of the liquid crystal molecules oriented in a convex arc shape along the y-axis direction on the second substrate 120-2 side.

[0064] It should be noted that, since the first substrate 120-1 and the second substrate 120-2 have a sufficiently large inter-substrate distance, the lateral electric field between the first transparent electrode 130-1 and the second transparent electrode 130-2 of the first substrate 120-1 will not affect the orientation of the liquid crystal molecules on the second substrate 120-2 side, or its effect is negligible. Similarly, the lateral electric field between the third transparent electrode 130-3 and the fourth transparent electrode 130-4 of the second substrate 120-2 will not affect the orientation of the liquid crystal molecules on the first substrate 120-1 side, or its effect is negligible.

[0065] When a potential is supplied to the fifth transparent electrode 130-5 to the eighth transparent electrode 130-8, the liquid crystal molecules of the second liquid crystal layer 160-2 are the same as those of the first liquid crystal layer 160-1, so the description is omitted here.

[0066] Next, the light distribution of the light transmitted through the optical element 10 will be explained. The light emitted from the light source has a polarized component along the x-axis (hereinafter referred to as the "P-polarized component") and a polarized component along the y-axis (hereinafter referred to as the "S-polarized component"). For convenience, the light will be explained below as having both the P-polarized component and the S-polarized component. That is, the light emitted from the light source (refer to...) Figure 4A as well as Figure 4B (1) in the text includes first polarized light 310 with P polarization component and second polarized light 320 with S polarization component. It should be noted that... Figure 4A as well as Figure 4B The arrow symbol and the cross symbol in the circle represent the P-polarized light component and the S-polarized light component, respectively.

[0067] After the first polarized light 310 is incident on the first substrate 120-1, as it moves toward the second substrate 120-2, its polarized composition changes from P-polarized to S-polarized due to the twisting of the liquid crystal molecules' orientation (see reference). Figure 4A as well as Figure 4B (2) to (4)). More specifically, the first polarized light 310 has a polarization axis in the x-axis direction on the first substrate 120-1 side, but its polarization axis gradually changes as it passes through the thickness direction of the first liquid crystal layer 160-1, and has a polarization axis in the y-axis direction on the second substrate 120-2 side, and then is emitted from the second substrate 120-2 side (see reference). Figure 4A as well as Figure 4B (5) in the middle.

[0068] Here, when a transverse electric field is generated between the first transparent electrode 130-1 and the second transparent electrode 130-2, the liquid crystal molecules on the first substrate 120-1 side are oriented in a convex arc shape along the x-axis due to the influence of this transverse electric field, resulting in a change in the refractive index distribution. Therefore, the first polarized light 310 diffuses along the x-axis according to the refractive index distribution of the liquid crystal molecules. Furthermore, when a transverse electric field is generated between the third transparent electrode 130-3 and the fourth transparent electrode 130-4, the liquid crystal molecules on the second substrate 120-2 side are oriented in a convex arc shape along the y-axis due to the influence of this transverse electric field, resulting in a change in the refractive index distribution. Therefore, the first polarized light 310 diffuses along the y-axis according to the change in the refractive index distribution of the liquid crystal molecules.

[0069] Therefore, in the absence of a transverse electric field (refer to...) Figure 4AThe polarization composition of the first polarized light 310 transmitted through the first liquid crystal cell 110-1 changes from P-polarized to S-polarized. On the other hand, in the case of generating a transverse electric field (see reference...), Figure 4B The polarization composition of the first polarized light 310 transmitted through the first liquid crystal unit changes from P polarization to S polarization and diffuses in the x-axis and y-axis directions.

[0070] After the second polarized light 320 is incident on the first substrate 120-1, as it moves toward the second substrate 120-2, its polarized composition changes from S-polarized to P-polarized due to the twisting of the liquid crystal molecules (see reference). Figure 4A as well as Figure 4B (2) to (4)). More specifically, the second polarized light 320 has a polarization axis in the y-axis direction on the first substrate 120-1 side, but its polarization axis gradually changes as it passes through the thickness direction of the first liquid crystal layer 160-1, and has a polarization axis in the x-axis direction on the second substrate 120-2 side, and then is emitted from the second substrate 120-2 side (see reference). Figure 4A as well as Figure 4B (5) in the middle.

[0071] Here, when a transverse electric field is generated between the first transparent electrode 130-1 and the second transparent electrode 130-2, the liquid crystal molecules on the first substrate 120-1 side are oriented in a convex arc shape along the x-axis due to the influence of this transverse electric field, resulting in a change in the refractive index distribution. However, since the polarization axis of the second polarized light 320 is orthogonal to the orientation of the liquid crystal molecules on the first substrate 120-1 side, it is unaffected by the refractive index distribution of the liquid crystal molecules and passes directly without diffusion. Similarly, when a transverse electric field is generated between the third transparent electrode 130-3 and the fourth transparent electrode 130-4, the liquid crystal molecules on the second substrate 120-2 side are oriented in a convex arc shape along the y-axis due to the influence of this transverse electric field, resulting in a change in the refractive index distribution. However, since the polarization axis of the second polarized light 320 is orthogonal to the orientation of the liquid crystal molecules on the second substrate 120-2 side, it is unaffected by the refractive index distribution of the liquid crystal molecules and passes directly without diffusion.

[0072] Therefore, not only in the case where no transverse electric field is generated (refer to...) Figure 4A Furthermore, in the case of generating a transverse electric field (refer to...) Figure 4B The polarization composition of the second polarized light 320 transmitted through the first liquid crystal unit 110-1 also changes from the S polarization composition to the P polarization composition, but does not diffuse.

[0073] The liquid crystal molecules of the second liquid crystal layer 160-2 of the second liquid crystal unit 110-2 also have the same refractive index distribution as the liquid crystal molecules of the first liquid crystal layer 160-1 of the first liquid crystal unit 110-1. However, since the polarization axis changes when the first polarized light 310 and the second polarized light 320 pass through the first liquid crystal unit 110-1, the polarized light affected by the refractive index distribution of the liquid crystal molecules of the second liquid crystal layer 160-2 is opposite. That is, not only in the case where no transverse electric field is generated (refer to...) Figure 4A Furthermore, in the case of generating a transverse electric field (refer to...) Figure 4B The polarization composition of the first polarized light 310 transmitted through the second liquid crystal cell 110-2 also changes from S-polarized light composition to P-polarized light composition, but does not diffuse (see reference). Figure 4A as well as Figure 4B (6) to (8)). On the other hand, in the case where no transverse electric field is generated (see (6) to (8)). Figure 4A The polarization composition of the second polarized light 320 transmitted through the second liquid crystal cell 110-2 changes only from the P polarization composition to the S polarization composition, but when a transverse electric field is generated (refer to...). Figure 4B The polarization composition of the second polarized light 320 transmitted through the second liquid crystal unit 110-2 changes from the P polarization composition to the S polarization composition, and diffuses in the x-axis direction and the y-axis direction.

[0074] As can be seen from the above, in the optical element 10, by stacking two liquid crystal units 110 with the same structure, the polarization composition of the light incident on the optical element 10 undergoes two changes. As a result, the polarization composition before and after incident remains unchanged (refer to...). Figure 4A as well as Figure 4B (1) and (9) in the above). On the other hand, when the optical element 10 supplies a potential to the transparent electrode 130, it can change the refractive index distribution of the liquid crystal molecules in the liquid crystal layer 160 of the liquid crystal cell 110, thereby refracting the light transmitted through the liquid crystal cell 110. More specifically, the first liquid crystal cell 110-1 can diffuse the light of the first polarized light 310 (P-polarized light component) in the x-axis direction, the y-axis direction, or both the x-axis and the y-axis directions, and the second liquid crystal cell 110-2 can diffuse the light of the second polarized light 320 (S-polarized light component) in the x-axis direction, the y-axis direction, or both the x-axis and the y-axis directions.

[0075] exist Figure 4A as well as Figure 4BIn this diagram, only the first liquid crystal cell 110-1 and the second liquid crystal cell 110-2 are shown, and the light distribution of light transmitted through the first liquid crystal cell 110-1 and the second liquid crystal cell 110-2 is described. However, the light distribution of light transmitted through the third liquid crystal cell 110-3 and the fourth liquid crystal cell 110-4 is also described in the same way. In the optical element 10, by increasing the number of stacked liquid crystal cells 110, the diffused light can be further diffused, and the shape of the light distribution can be significantly changed.

[0076] [4. Control of the potential supply to the transparent electrode 130 of the optical element 10]

[0077] Figure 5 This is a schematic diagram illustrating the connection between the transparent electrode 130 of the optical element 10 and the switching circuit section 220 in an optical device 1 according to one embodiment of the present invention. It should be noted that... Figure 5 Only the first transparent electrode 130-1 to the fourth transparent electrode 130-4 of the first liquid crystal cell 110-1 are shown. Additionally, in Figure 5 In the diagram, the second substrate 120-2 is shown in dashed lines for clarity.

[0078] The first transparent electrode 130-1, the second transparent electrode 130-2, the third transparent electrode 130-3, and the fourth transparent electrode 130-4 are electrically connected to the first potential signal line 224-1, the second potential signal line 224-2, the third potential signal line 224-3, and the fourth potential signal line 224-4, respectively. The switching circuit section 220 includes a first switching circuit 222-1, a second switching circuit 222-2, a third switching circuit 222-3, and a fourth switching circuit 222-4. These circuits are electrically connected to the first potential signal line 224-1, the second potential signal line 224-2, the third potential signal line 224-3, and the fourth potential signal line 224-4, respectively. Therefore, the first potential signal controlled by the first switching circuit is input to the first transparent electrode 130-1 via the first potential signal line 224-1. Similarly, the second potential signal controlled by the second switching circuit is input to the second transparent electrode 130-2 via the second potential signal line 224-2, the third potential signal controlled by the third switching circuit is input to the third transparent electrode 130-3 via the third potential signal line 224-3, and the fourth potential signal controlled by the fourth switching circuit is input to the fourth transparent electrode 130-4 via the fourth potential signal line 224-4. Thus, in the first liquid crystal cell 110-1, the switching circuit 222 included in the switching circuit section 220 can independently supply potential to each of the transparent electrodes 130. It should be noted that the same applies to the second liquid crystal cells 110-2 to the fourth liquid crystal cells 110-4, therefore, descriptions are omitted here.

[0079] Figure 6 This is a circuit diagram showing the switching circuit 222 included in the switching circuit section 220 of the optical device 1 according to one embodiment of the present invention. It should be noted that... Figure 6 In the diagram, only the first switch circuit 222-1, which is electrically connected to the first transparent electrode 130-1, is shown. However, the structures of the second switch circuit 222-2 to the fourth switch circuit 222-4 are the same as those of the first switch circuit 222-1.

[0080] The first switching circuit 222-1 includes a first transistor Tr1, a second transistor Tr2, and a third transistor Tr3. In the first transistor Tr1, one of its source and drain is electrically connected to a first power supply line 226-1 supplying a first potential V1 from the first power supply unit 210, and the other of its source and drain is electrically connected to a first potential signal line 224-1. Additionally, a first control signal line 228-1 is electrically connected to the gate of the first transistor Tr1, and a first control signal CL1 generated by the control signal generation circuit unit 230 is input to the gate of the first transistor Tr1. In the second transistor Tr2, one of its source and drain is electrically connected to a second power supply line 226-2 supplying a second potential V2 from the second power supply unit 210, and the other of its source and drain is electrically connected to the first potential signal line 224-1. Additionally, a second control signal line 228-2 is electrically connected to the gate of the second transistor Tr2, and a second control signal CL2 generated by the control signal generation circuit unit 230 is input to the gate of the second transistor Tr2. In the third transistor Tr3, one of its source and drain is electrically connected to the third power supply line 226-3, which supplies the third potential V3 from the third power supply unit 210, and the other of its source and drain is electrically connected to the first potential signal line 224-1. Additionally, the third control signal line 228-3 is electrically connected to the gate of the third transistor Tr3, and the third control signal CL3 generated by the control signal generation circuit unit 230 is input to the gate of the third transistor Tr3.

[0081] In the first switching circuit 222-1, any one of the first potential V1, the second potential V2, and the third potential V3 is selected by the first control signal CL1, the second control signal CL2, and the third control signal CL3. A first potential signal VL1 containing the selected potential is then output to the first potential signal line 224-1. It should be noted that, for convenience, the first potential V1, the second potential V2, and the third potential V3 are sometimes set to 30V, 15V, and 0V respectively in the following description. However, the potentials of the first potential V1, the second potential V2, and the third potential V3 are not limited to these values.

[0082] Figure 7A as well as Figure 7B This is a timing diagram illustrating the relationship between the control signal input to the switching circuit section 220 and the potential signal output from the switching circuit section 220 in an optical device 1 according to one embodiment of the present invention. It should be noted that... Figure 7A as well as Figure 7B The diagram only shows the first potential signal VL1 output to the first potential signal line 224-1, but the second potential signal VL2 output to the second potential signal line 224-2 is also shown, so the description is omitted here.

[0083] like Figure 7A As shown, a first control signal CL1 is input to the switching circuit section 220, thereby supplying a first potential V1 (30V) to the first potential signal line 224-1. Furthermore, by stopping the input of the first control signal CL1 to the switching circuit section 220 and inputting a second control signal CL2, a second potential V2 (15V) is supplied to the first potential signal line 224-1. Furthermore, by stopping the input of the second control signal CL2 to the switching circuit section 220 and inputting a third control signal CL3, a third potential V3 (0V) is supplied to the first potential signal line 224-1. Therefore, the first potential signal VL1 is a signal containing the first potential, the second potential, and the third potential, and any one of the first potential, the second potential, and the third potential is supplied to the first transparent electrode 130-1 connected to the first potential signal line 224-1.

[0084] It should be noted that, in Figure 7A In the process, the pulse widths of the first control signal CL1 to the third control signal CL3 are the same, but as... Figure 7B As shown, the pulse widths of the first control signal CL1 to the third control signal CL3 can also be different. Even in this case, the first potential signal VL1 becomes a signal containing a first potential, a second potential, and a third potential based on the respective pulse widths of the first control signal CL1, the second control signal CL2, and the third control signal CL3.

[0085] Figures 8-10 This is a timing diagram showing the relationship between the potential signal and the potential difference between the transparent electrode 130 in an optical device 1 according to one embodiment of the present invention. It should be noted that... Figures 8-10 The image shows a first potential signal VL1 input to the first transparent electrode 130-1, a second potential signal VL2 input to the second transparent electrode 130-2, and the potential difference VL1-VL2 between the first transparent electrode 130-1 and the second transparent electrode 130-2.

[0086] exist Figure 8In this configuration, the first potential signal VL1 sequentially supplies +30V, +15V, 0V, and +15V to the first transparent electrode 130-1. Similarly, the second potential signal VL2 sequentially supplies 0V, +15V, +30V, and +15V to the second transparent electrode 130-2. Both the first and second potential signals VL1 and VL2 have the same pulse width but are phase-reversed. Therefore, a potential difference (VL1-VL2) of +30V, 0V, -30V, and 0V is generated between the first and second transparent electrodes 130-1 and 130-2. In this case, when the potential difference is +30V and -30V, the orientation state of the liquid crystal molecules in the first liquid crystal layer 160-1 changes, thereby allowing light transmitted through the first liquid crystal cell 110-1 to diffuse. Therefore, in the optical device 1, the light distribution can be controlled by the potential difference between the transparent electrodes 130 having a pulse width H relative to the period T (since the orientation state of the liquid crystal molecules is the same under potential differences of +30 and -30V, the repetition unit of |VL1-VL2| is defined as one period here).

[0087] The third transparent electrode 130-3 and the fourth transparent electrode 130-4 are the same as the first transparent electrode 130-1 and the second transparent electrode 130-2. In addition, the second liquid crystal unit 110-2, the third liquid crystal unit 110-3 and the fourth liquid crystal unit 110-4 are the same as the first liquid crystal unit 110-1.

[0088] The phases of the first potential signal VL1 and the second potential signal VL2 can also be shifted. (Refer to...) Figure 9 This needs to be explained.

[0089] exist Figure 9In this embodiment, the first potential signal VL1 is a signal that sequentially supplies potentials of 30V, +15V, 0V, and +15V to the first transparent electrode 130-1. Similarly, the second potential signal VL2 is a signal that sequentially supplies potentials of 0V, +15V, +30V, and +15V to the second transparent electrode 130-2. However, the phase of the second potential signal VL2 differs from that of the first potential signal VL1. Specifically, the phase of the second potential signal VL2 is offset by +45° (π / 4) relative to the first potential signal VL1. More specifically, the second potential signal VL2 is out of phase relative to the first potential signal VL1 and further delayed by π / 4. Thus, in this embodiment, the second potential signal VL2 has a phase other than the inversion of the phase of the first potential signal VL1. Therefore, potential differences of +15V, +30V, +15V, 0V, -15V, -30V, -15V, and 0V are generated between the first transparent electrode 130-1 and the second transparent electrode 130-2. In this case, when the potential difference is +15V, +30V, -15V, and -30V, the orientation state of the liquid crystal molecules in the first liquid crystal layer 160-1 changes, and light transmitted through the first liquid crystal cell 110-1 can diffuse. Figure 9 In the timing diagram shown, by combining the first potential signal VL1 or the second potential signal VL2, the light distribution can be controlled by the potential difference between transparent electrodes 130, which have pulse widths different from their pulse widths.

[0090] The first power supply potential signal and the second power supply potential signal may not have the same pulse width. (Refer to...) Figure 10 This needs to be explained.

[0091] exist Figure 10In this circuit, the first potential signal VL1 sequentially supplies potentials of 30V, +15V, 0V, and +15V to the first transparent electrode 130-1. Similarly, the second potential signal VL2 sequentially supplies potentials of 0V, +15V, +30V, and +15V to the second transparent electrode 130-2. However, the pulse width of the second potential signal VL2 differs from that of the first potential signal. More specifically, the phases of the first potential signal VL1 and the second potential signal VL2 are reversed, but the pulse width of the second potential signal VL2 is half that of the first potential signal VL1. Therefore, although the first potential signal VL1 oscillates with a pulse width, there is a portion of the time when the second potential signal VL2 has an intermediate potential. Thus, a potential difference (VL1-VL2) of +30V, +15V, 0V, -30V, -15V, and 0V is generated between the first transparent electrode 130-1 and the second transparent electrode 130-2. In this case, when the potential difference is +15V, +30V, -15V, and -30V, the orientation state of the liquid crystal molecules in the first liquid crystal layer 160-1 changes, allowing light transmitted through the first liquid crystal cell 110-1 to diffuse. Figure 10 In the timing diagram shown, the light distribution can also be controlled by the potential difference between transparent electrodes 130 that have pulse widths different from those of the first potential signal VL1 or the second potential signal VL2.

[0092] As described above, in the optical device 1, by changing the pulse width or phase of the potential signal input to the transparent electrode 130, various pulse widths and duty cycles (e.g., relative to the voltage) can be used. Figure 8 The light distribution is controlled by so-called pulse width modulation (PWM) driving the pulse width H of the period T shown. It should be noted that the pulse width or duty cycle of the potential difference between the transparent electrodes 130 can also cause the pulse width of the first control signal CL1, the second control signal CL2, and the third control signal CL3 to change.

[0093] As described above, in optical device 1, the potential supplied to optical element 10 can be selected using only an analog switch, and optical element 10 can be controlled by PWM drive. That is, optical device 1 does not require expensive components such as DACs or AMPs. Therefore, optical device 1 can be manufactured inexpensively, and manufacturing costs can be suppressed.

[0094] Example

[0095] Figure 11 This is a graph showing the light distribution state of the optical device 1 according to one embodiment of the present invention. Figure 11The horizontal axis of the graph shown represents the duty cycle (%), and the vertical axis represents the half-value angle (degrees). Furthermore, the half-value angle is the angle at which the light has 50% of the brightness relative to the brightness of the front (0 degrees) of the optical device 1 in an angle-dependent measurement of brightness. That is, if the half-value angle increases, it means that the light is diffused more.

[0096] The fabricated optical device 1 has four liquid crystal units 110 on the optical element 10. The width of the transparent electrode 130 of each liquid crystal unit 110 is 8 (μm), and the distance between the transparent electrodes 130 is 8 (μm). In addition, the period T of the power supply potential signal input to each transparent electrode 130 is 60 Hz.

[0097] like Figure 11 As shown, the half-value angle increases with increasing duty cycle. That is, it can be seen that the light is diffused considerably by optical device 1. In particular, it can be seen that the light diffuses significantly when the duty cycle exceeds 10%.

[0098] It is understood that, within the scope of the present invention, those skilled in the art can conceive of various modifications and alterations, which also fall within the scope of the present invention. For example, for the above embodiments, embodiments in which those skilled in the art appropriately add, delete, or design changes to constituent elements, or embodiments in which steps are added, omitted, or conditions are changed, are also included within the scope of the present invention, as long as they possess the spirit of the present invention.

[0099] Furthermore, any other effects or benefits resulting from the method described in this embodiment, as well as those that can be reasonably conceived by those skilled in the art, are of course considered to be effects brought about by this invention.

[0100] Symbol Explanation

[0101] 1. Optical device; 10. Optical element; 20. Control unit; 30. Light source; 110. Liquid crystal unit; 120. Substrate; 130. Transparent electrode; 140. Alignment film; 150. Sealing material; 160. Liquid crystal layer; 170. Optical elastic resin layer; 210. Power supply unit; 220. Switching circuit unit; 222. Switching circuit; 224. Potential signal line; 226. Power line; 228. Control signal line; 230. Control signal generation circuit unit; 310. First polarized light; 320. Second polarized light.

Claims

1. An optical device, comprising: An optical element comprising at least one liquid crystal unit for distributing light irradiated from a light source; The power supply section generates a first potential and a second potential different from the first potential. The control signal generation circuit generates a control signal that controls the pulse width of the first potential and the second potential, respectively. as well as The switching circuit section, based on the control signal, outputs a first potential signal, which includes a first potential having a first pulse width and a second potential having a second pulse width. The at least one liquid crystal unit includes: A first substrate, wherein a first transparent electrode and a second transparent electrode are alternately disposed in a first direction; A second substrate, wherein a third transparent electrode and a fourth transparent electrode are alternately disposed in a second direction intersecting the first direction; and The liquid crystal layer between the first substrate and the second substrate The first potential signal is input to the first transparent electrode. When no potential is applied to the first transparent electrode, the second transparent electrode, the third transparent electrode, and the fourth transparent electrode, the liquid crystal molecules of the liquid crystal layer are oriented in a twisted state as the long axis of the liquid crystal molecules changes from the first direction to the second direction as they move from the first substrate toward the second substrate.

2. The optical device according to claim 1, wherein, The second pulse width is different from the first pulse width.

3. The optical device according to claim 1, wherein, The switching circuit section also outputs a second potential signal, the second potential signal including the first potential having the first pulse width and the second potential having the second pulse width. The second phase of the second potential signal is different from the first phase of the first potential signal. The second potential signal is input to the second transparent electrode.

4. The optical device according to claim 3, wherein, The second phase is the first phase that has been reversed.

5. The optical device according to claim 1, wherein, The power supply unit also generates a third potential that is different from the first potential and the second potential. The control signal generation circuit also generates a control signal that controls the pulse width of the third potential. The switching circuit section also outputs a first potential signal that includes the third potential having a third pulse width.

6. An optical device, comprising: An optical element comprising at least one liquid crystal unit for distributing light irradiated from a light source; The power supply unit includes a first power supply that generates a first potential and a second power supply that generates a second potential different from the first potential. The control signal generation unit generates a first control signal, a second control signal, a third control signal, and a fourth control signal that respectively control the pulse width of the first potential and the second potential; as well as The switching circuit section, electrically connected to both the first power supply and the second power supply, includes a first switching circuit that outputs a first potential signal based on the first control signal, a second switching circuit that outputs a second potential signal based on the second control signal, a third switching circuit that outputs a third potential signal based on the third control signal, and a fourth switching circuit that outputs a fourth potential signal based on the fourth control signal. The optical element includes at least one liquid crystal unit. The at least one liquid crystal unit includes: A first substrate, wherein a first transparent electrode and a second transparent electrode are alternately disposed in a first direction; A second substrate, wherein a third transparent electrode and a fourth transparent electrode are alternately disposed in a second direction intersecting the first direction; The liquid crystal layer between the first substrate and the second substrate The first transparent electrode, the second transparent electrode, the third transparent electrode, and the fourth transparent electrode are respectively electrically connected to the first switching circuit, the second switching circuit, the third switching circuit, and the fourth switching circuit. The first potential signal, the second potential signal, the third potential signal, and the fourth potential signal are respectively input to the first transparent electrode, the second transparent electrode, the third transparent electrode, and the fourth transparent electrode. When no potential is applied to the first transparent electrode, the second transparent electrode, the third transparent electrode, and the fourth transparent electrode, the liquid crystal molecules of the liquid crystal layer are oriented in a twisted state as the long axis of the liquid crystal molecules changes from the first direction to the second direction as they move from the first substrate toward the second substrate.

7. The optical device according to claim 6, wherein, The power supply unit also includes a third power source for generating a third potential. The control signal generation unit also generates a first control signal, a second control signal, a third control signal, and a fourth control signal, which respectively control the pulse width of the third potential. The first switch circuit, the second switch circuit, the third switch circuit, and the fourth switch circuit are each electrically connected to the third power supply.

8. The optical device according to claim 6, wherein, The phase of the first potential signal is the phase of the second potential signal that has been inverted. The phase of the third potential signal is the phase of the fourth potential signal that has been reversed.

9. The optical device according to claim 6, wherein, The pulse width based on the difference between the first potential signal and the second potential signal has a duty cycle of more than 10%.

10. The optical device according to any one of claims 1 to 9, wherein, The first potential is twice the second potential.

11. The optical device according to any one of claims 1 to 9, wherein, The at least one liquid crystal unit is four liquid crystal units.

12. The optical device according to claim 10, wherein, The at least one liquid crystal unit is four liquid crystal units.

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