Lighting device

Abstract

A lighting device is provided with: two control substrates (5); two relay substrates (4) electrically connected to each of the two control substrates via a wire harness (210); and four liquid crystal panels (1) electrically connected to the two relay substrates via a flexible printed circuit substrate (200). The number of the flexible printed circuit substrates is four. Two liquid crystal panels in the four liquid crystal panels are electrically connected with one of the two relay substrates through one flexible printed circuit substrate respectively, and the other two liquid crystal panels in the four liquid crystal panels are electrically connected with the other one of the two relay substrates through one flexible printed circuit substrate respectively. The four liquid crystal panels are arranged in a state of being stacked in the Z direction.

Description

Technical Field

[0001] The present disclosure relates to a lighting device. Background Art

[0002] There are known lighting devices having a light source such as an LED (for example, refer to Patent Document 1). The lighting device of Patent Document 1 is an LED lamp including a lamp head, an LED (light source), and a cylinder member connecting the lamp head and the LED. Since the cylinder member has flexibility, the orientation of the LED with respect to the lamp head can be changed by bending and deforming the cylinder member with respect to the axial direction.

[0003] In addition, when the shape (light distribution pattern) of the emitted light from the lighting device is not circular centered on the optical axis (for example, elongated in one direction), a lighting device capable of rotating the light distribution pattern centered on the axis is desired.

[0004] It is envisioned that such a lighting device includes, for example: a first cylindrical member, a second cylindrical member rotatably supporting the first cylindrical member, a liquid crystal panel fixed to the first cylindrical member, a control substrate fixed to the second cylindrical member and controlling the liquid crystal panel, and wirings electrically connecting the liquid crystal panel and the control substrate.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-48029 Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] However, when the first cylindrical member fixed with the liquid crystal panel rotates with respect to the second cylindrical member fixed with the control substrate, the wirings are twisted, and the connection portion between the wirings and the liquid crystal panel or the connection portion between the wirings and the control substrate may be damaged.

[0010] An object of the present disclosure is to provide a lighting device that can suppress damage to the connection portion between the wirings and the liquid crystal panel or the connection portion between the wirings and the control substrate in a lighting device that rotates the light distribution pattern centered on the axis.

[0011] Solution to the Technical Problem

[0012] The lighting device according to one form of the present disclosure includes: two control substrates, two relay substrates each electrically connected to the two control substrates via a wire harness, and four liquid crystal panels electrically connected to the two relay substrates via flexible printed circuit boards. Four flexible printed circuit boards are provided. Two of the four liquid crystal panels are each electrically connected to one of the two relay substrates via one of the flexible printed circuit boards, and the other two of the four liquid crystal panels are each electrically connected to the other of the two relay substrates via one of the flexible printed circuit boards. The four liquid crystal panels are arranged in a stacked state in a first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional view of the lighting device according to the first embodiment.

[0014] Figure 2 is Figure 1 exploded perspective view of

[0015] Figure 3 is a schematic view of observing the liquid crystal panel, the flexible printed circuit board, and the relay substrate from the front.

[0016] Figure 4 is a schematic view of observing the liquid crystal panel, the flexible printed circuit board, and the relay substrate from the back.

[0017] Figure 5 is a schematic view showing a state where the liquid crystal panel and the flexible printed circuit board are rotated, and corresponds to Figure 4 corresponds to.

[0018] Figure 6 is an exploded perspective view of four liquid crystal panels and flexible printed circuit boards.

[0019] Figure 7 is a cross-sectional view showing a state where four liquid crystal panels are stacked.

[0020] Figure 8 is a cross-sectional view of the liquid crystal panel.

[0021] Figure 9 is a schematic view of observing the liquid crystal panel from the front.

[0022] Figure 10 is a schematic view showing the surface of the first substrate included in the liquid crystal panel.

[0023] Figure 11 is a schematic view showing the surface of the second substrate included in the liquid crystal panel.

[0024] Figure 12 is Figure 10 cross-sectional view taken along line XII-XII of

[0025] Figure 13 It is a schematic diagram showing an example of the rotation of a light distribution pattern.

[0026] Figure 14A It is a cross-sectional view of a liquid crystal panel, showing the alignment state of liquid crystal molecules in a state where no voltage is applied to the electrodes for driving the liquid crystal.

[0027] Figure 14B It is a cross-sectional view of a liquid crystal panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the electrodes for driving the liquid crystal.

[0028] Figure 14C It is a diagram showing the waveform of the control signal applied to the electrodes for driving the liquid crystal.

[0029] Figure 15A It is a schematic perspective view of a liquid crystal panel, showing the arrangement of the first driving electrodes and the second driving electrodes.

[0030] Figure 15B It is a schematic perspective view of a liquid crystal panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the second driving electrodes.

[0031] Figure 16 It is a diagram schematically showing the state of diffusion of P-waves and S-waves in a state where a second liquid crystal panel is laminated on a first liquid crystal panel.

[0032] Figure 17 It is a diagram schematically explaining the state of diffusion of P-waves and S-waves using four liquid crystal panels according to the first embodiment.

[0033] Figure 18 It is a schematic diagram showing the overall configuration of the liquid crystal panel, relay substrate, and control substrate according to the first embodiment.

[0034] Figure 19A It is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four liquid crystal panels.

[0035] Figure 19B It is a diagram comprehensively explaining the polarization waves, the diffusion directions of the polarization waves, and the potentials of the terminals acting in each of the four liquid crystal panels.

[0036] Figure 20A It is a diagram showing the waveform of the control signal applied to the electrodes for driving the liquid crystal in a light distribution pattern with narrow light distribution.

[0037] Figure 20B It is an image showing the light distribution pattern with narrow light distribution.

[0038] Figure 21AIt is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of horizontal light distribution.

[0039] Figure 21B It is an image showing the light distribution pattern of horizontal light distribution.

[0040] Figure 22 It is a diagram schematically illustrating a state of forming a light distribution pattern of horizontal light distribution using four liquid crystal panels.

[0041] Figure 23A It is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of vertical light distribution.

[0042] Figure 23B It is an image showing the light distribution pattern of vertical light distribution.

[0043] Figure 24 It is a diagram schematically illustrating a state of forming a light distribution pattern of vertical light distribution using four liquid crystal panels.

[0044] Figure 25A It is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of elliptical light distribution.

[0045] Figure 25B It is an image showing the light distribution pattern of elliptical light distribution.

[0046] Figure 26A It is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of circular light distribution.

[0047] Figure 26B It is an image showing the light distribution pattern of circular light distribution.

[0048] Figure 27 It is a schematic diagram showing the overall configuration of the liquid crystal panel, relay substrate, and control substrate according to the second embodiment.

[0049] Figure 28 It is a cross-sectional view showing a state where four liquid crystal panels are stacked.

[0050] Figure 29A It is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four liquid crystal panels.

[0051] Figure 29B It is a diagram showing the polarization wave, the diffusion direction of the polarization wave, and the potential of the terminals acting in each of the four liquid crystal panels as a whole.

[0052] Figure 30A It is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of cross light distribution.

[0053] Figure 30B It is an image showing a light distribution pattern of cross light distribution.

[0054] Figure 31 It is a diagram schematically showing a state of forming a light distribution pattern of cross light distribution using four liquid crystal panels. Detailed implementation mode

[0055] The mode (implementation mode) for implementing the present disclosure will be described in detail with reference to the accompanying drawings. The present disclosure is not limited to the content described in the following implementation modes. In addition, the constituent elements described below include elements that can be easily conceived by those skilled in the art and substantially identical elements. Furthermore, the constituent elements described below can be appropriately combined.

[0056] It should be noted that the disclosure is merely an example, and appropriate changes that can be easily conceived by those skilled in the art while maintaining the gist of the disclosure are of course included in the scope of the present disclosure. In addition, for the purpose of making the description clearer, the drawings sometimes schematically show the width, thickness, shape, etc. of each part compared with the actual form, but this is only an example and does not limit the interpretation of the present disclosure. In addition, in this specification and each figure, sometimes the same reference numerals are assigned to elements that are the same as the foregoing elements with respect to the figures that have appeared, and the detailed description is appropriately omitted.

[0057] [First Embodiment]

[0058] First, the lighting device according to the first embodiment will be described.

[0059] (Configuration of lighting device)

[0060] Figure 1 It is a schematic cross-sectional view of the lighting device according to the first embodiment. Figure 2 It is Figure 1 exploded perspective view of Figure 3 It is a schematic view of observing the liquid crystal panel, flexible printed circuit board, and relay board from the front. Figure 4 It is a schematic view of observing the liquid crystal panel, flexible printed circuit board, and relay board from the back. Figure 5 It is a schematic view showing a state where the liquid crystal panel and the flexible printed circuit board are rotated, and corresponds to Figure 4 corresponding. Figure 6 It is an exploded perspective view of four liquid crystal panels and a flexible printed circuit board. Figure 7 It is a cross-sectional view showing a state where four liquid crystal panels are stacked.

[0061] As Figure 1 and Figure 2As shown, the lighting device 100 according to the first embodiment includes: an optical element 1, a holding member 2, a held member 3, a relay substrate 4, a control substrate 5, a flexible printed circuit board 200, a wire harness 210, and an LED (light source) 110.

[0062] The holding member 2 is a cylindrical member having a central axis AX. The holding member 2 rotates relative to the held member 3 in the axial direction around the central axis AX. Thus, as described later Figure 5 As shown, the four liquid crystal panels 1A rotate in the axial direction around the central axis AX. The central axis AX extends in the Z direction (axial direction, first direction). That is, the axial direction of the central axis AX is the same direction as the Z direction and the first direction. On the inner periphery of the holding member 2, protrusions 53 project toward the radially inner side. The protrusions 53 are annularly connected over the entire circumference of the inner periphery of the holding member 2.

[0063] The held member 3 is a cylindrical member having a central axis AX. The front end portion of the held member 3 is fitted into the inner periphery of the holding member 2. On the outer periphery of the held member 3, a groove 54 is provided that is recessed toward the radially inner side. The protrusions 53 of the holding member 2 are fitted into the groove 54. Thus, the holding member 2 rotates relative to the held member 3 in the axial direction around the central axis AX.

[0064] The optical element 1 is, for example, a plurality of liquid crystal panels 1A. As Figure 6 and Figure 7 shown, the optical element 1 includes, for example: a first liquid crystal panel 10, a second liquid crystal panel 20, a third liquid crystal panel 30, and a fourth liquid crystal panel 40. Specifically, the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30, and the fourth liquid crystal panel 40 are stacked in the axial direction in order from the closest to the LED 110. In other words, the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30, and the fourth liquid crystal panel 40 are stacked in the order from the Z2 side to the Z1 side. Specifically, as Figure 3 and Figure 4 shown, one liquid crystal panel is mounted on the back surface of a ring-shaped (circular ring-shaped) frame 50, and in the state where these frames 50 and one liquid crystal panel are arranged, four are overlapped in the Z direction (axial direction). At this time, as Figure 6 and Figure 7As shown, the liquid crystal panels adjacent to each other in the axial direction are bonded to each other via a bonding layer 57. The bonding layer 57 is a light-transmissive functional film having double-sided adhesiveness such as an OCA (Optical Clear Adhesive), for example. The frame 50 is fixed to the inner periphery of the holding member 2. That is, the liquid crystal panel 1A is fixed to the holding member 2 via the frame 50. It should be noted that the cylindrical member 52 is attached to the frame 50. In addition, the flexible printed circuit board 200 includes four flexible printed circuit boards 201A, 202A, 203A, and 204A. As Figure 6 and Figure 7 shown, the flexible printed circuit board 201A is joined to the first liquid crystal panel 10, the flexible printed circuit board 202A is joined to the second liquid crystal panel 20, the flexible printed circuit board 203A is joined to the third liquid crystal panel 30, and the flexible printed circuit board 204A is joined to the fourth liquid crystal panel 40. The flexible printed circuit boards 201A and 203A extend in the same direction, and the flexible printed circuit boards 202A and 204A extend in the same direction. The flexible printed circuit boards 201A and 203A extend in a direction opposite to that of the flexible printed circuit boards 202A and 204A.

[0065] As Figure 1 and Figure 2 shown, the relay substrate 4 is attached to the outer periphery of the cylindrical member 52. That is, the relay substrate 4 is fixed to the holding member 2 via the cylindrical member 52 and the frame 50. As Figure 2 shown, the relay substrate 4 has two relay substrates 4A and 4B. The relay substrate 4B includes a substrate body 44, connectors 634, 635, and 636 (see Figure 18 ). The connectors 634, 635, and 636 are provided on the substrate body 44. The connector 636 is disposed at a position on the substrate body 44 closer to the held member 3, and the connectors 634 and 635 are disposed at positions on the substrate body 44 closer to the holding member 2. In other words, the connector 636 is disposed on the Z2 side of the substrate body 44, and the connectors 634 and 635 are disposed on the Z1 side of the substrate body 44. A wiring harness 210 is connected to the connector 636. The flexible printed circuit board 200 is connected to the connectors 634 and 635. It should be noted that the relay substrate 4A also has the same configuration as the relay substrate 4B, and the specific connection is as shown in Figure 18 below.

[0066] As Figure 1 shown, the heat sink 55 is attached to the inner periphery of the held member 3 via the mounting member 56. The LED 110 is fixed to the surface of the heat sink 55 on the Z1 side. That is, the LED 110 is fixed to the held member 3 via the heat sink 55 and the mounting member 56.

[0067] AsFigure 1 and Figure 2 As shown in Figure 2 , the control substrate 5 is mounted on the inner periphery of the held member 3. The control substrate 5 controls the liquid crystal panel 1A.

[0068] As Figure 1 and Figure 2 As shown in Figure 1 and Figure 2 , the flexible printed circuit board 200 is electrically connected to the liquid crystal panel 1A and the relay substrate 4. The wire harness 210 is electrically connected to the relay substrate 4 and the control substrate 5. The flexible printed circuit board 200 and the wire harness 210 extend in the axial direction (Z direction). The length of the flexible printed circuit board 200 is shorter than the length of the wire harness 210. As described above, the holding member 2 rotates relative to the held member 3. When the rotation angle of the holding member 2 relative to the held member 3 is 0 degrees, the wire harness 210 is in a slack state. Moreover, when the rotation angle of the holding member 2 relative to the held member 3 is 360 degrees (the state where the holding member 2 has rotated one week relative to the held member 3), the wire harness 210 is still in a slack state and has an extra length.

[0069] (Configuration of liquid crystal panel)

[0070] Figure 8 is a cross-sectional view of the liquid crystal panel. Figure 9 is a schematic view of the liquid crystal panel observed from the front. Figure 10 is a schematic view showing the surface of the first substrate included in the liquid crystal panel. Figure 11 is a schematic view showing the surface of the second substrate included in the liquid crystal panel. Figure 12 is Figure 10 a cross-sectional view taken along line XII - XII of

[0071] As Figure 9 shown, the liquid crystal panel 1A includes a first substrate S11 and a second substrate S12 disposed on the Z1 side of the first substrate S11. The liquid crystal panel 1A is a regular octagon in plan view and has a first side 11, a second side 12, a third side 13, a fourth side 14, a fifth side 15, a sixth side 16, a seventh side 17, and an eighth side 18. In the present invention, the outer shape of the liquid crystal panel 1A is not particularly limited, and polygons other than octagons, as well as circles and ellipses, are also included in the present invention. It should be noted that in the present embodiment, the four liquid crystal panels 1A stacked in the Z direction (axial direction) have the same structure.

[0072] The first side 11 is located on the Y1 side of the liquid crystal panel 1A. The first side 11 is parallel to the X direction in the figure. The first side 11 of the liquid crystal panel 1A coincides with Figure 10 the first side 211 of the first substrate S11 shown in Figure 10 . In contrast, Figure 11The first side 311 of the second substrate S12 shown is located on the Y2 side relative to the first side 211 of the first substrate S11. Therefore, as Figure 10 shown, when the second substrate S12 is stacked on the front side of the first substrate S11, the end portion 2Ac on the Y1 side of the first substrate S11 is exposed. A first terminal group 10A is provided at the end portion 2Ac.

[0073] The second side 12 is located on the X1 side in the liquid crystal panel 1A. The second side 12 is parallel to the Y direction in the figure. The second side 12 of the liquid crystal panel 1A coincides with Figure 10 the second side 212 of the first substrate S11 shown. In contrast, Figure 11 the second side 312 of the second substrate S12 shown is located on the X2 side relative to the second side 212 of the first substrate S11. Therefore, as Figure 9 shown, when the second substrate S12 is stacked on the front side of the first substrate S11, the end portion 2Ad on the X1 side of the first substrate S11 is exposed. A second terminal group 20A is provided at the end portion 2Ad.

[0074] The third side 13 intersects both the X1 direction and the Y1 direction. The intersection angle is 45 degrees. The third side 13 coincides with Figure 10 the third side 213 of the first substrate S11 shown. In contrast, Figure 11 the third side 313 of the second substrate S12 shown is located on the X2 side and the Y2 side relative to the third side 213 of the first substrate S11. In other words, when viewed from above, the third side 313 of the second substrate S12 is located on the center side relative to the third side 213 of the first substrate S11. Therefore, as Figure 9 shown, when the second substrate S12 is stacked on the front side of the first substrate S11, the end portion 2Ae of the first substrate S11 is exposed.

[0075] The fourth side 14 intersects both the X1 direction and the Y2 direction. The intersection angle is 45 degrees. The fourth side 14 coincides with Figure 10 the fourth side 214 of the first substrate S11 shown and Figure 11 the fourth side 314 of the second substrate S12 shown.

[0076] The fifth side 15 is located on the Y2 side in the liquid crystal panel 1A. The fifth side 15 coincides with Figure 10 the fifth side 215 of the first substrate S11 shown and Figure 12 the fifth side 315 of the second substrate S12 shown.

[0077] The sixth side 16 intersects both the X2 direction and the Y2 direction. The intersection angle is 45 degrees. The sixth side 164 coincides with Figure 10 the sixth side 216 of the first substrate S11 shown andFigure 11 coincides with the sixth side 316 of the second substrate S12 shown.

[0078] The seventh side 17 is located on the X2 side in the liquid crystal panel 1A. The seventh side 17 coincides with Figure 10 the seventh side 217 of the first substrate S11 shown and Figure 11 the seventh side 317 of the second substrate S12 shown.

[0079] The eighth side 18 intersects both the X2 direction and the Y1 direction. The intersection angle is 45 degrees. The eighth side 18 coincides with Figure 10 the eighth side 218 of the first substrate S11 shown and Figure 11 the eighth side 318 of the second substrate S12 shown.

[0080] Thus, since the area of the second substrate S12 is smaller than the area of the first substrate S11, the first terminal group 10A provided at the end 2Ac of the first substrate S11 and the second terminal group 20A provided at the end 2Ad are exposed. It should be noted that the first terminal group 10A or the second terminal group 20A is electrically connected to the flexible printed circuit board 200.

[0081] Next, refer to Figure 10 and Figure 11 to describe the first substrate S11 and the second substrate S12. In Figure 10 , the center line CL1 passing through the center of the first substrate S11 in the X direction and extending in the Y direction and the center line CL2 passing through the center of the first substrate S11 in the Y direction and extending in the X direction are shown. In Figure 11 , the center line CL1 and the center line CL2 are also shown.

[0082] As Figure 10 shown, in the end 2Ac along the first side 211 of the first substrate S11, a first terminal group 10A is provided at a first end 21A (indicated by a double-dot dash line) closer to the second side 212 side (or the third side 213 side) than the center of the first side 211. That is, the end 2Ac is the end on the Y1 side in the first substrate S11, and in the part of the end 2Ac, a first end 21A indicated by a double-dot dash line is arranged closer to the X1 side than the center line CL1. The first terminal group 10A is provided at the first end 21A. As Figure 10 shown, the first terminal group 10A includes a first terminal 101, a second terminal 102, a third terminal 103, and a fourth terminal 104. The first terminal 101, the second terminal 102, the third terminal 103, and the fourth terminal 104 are arranged in sequence in the X direction from the X1 side to the X2 side. These terminals 101, 102, 103, 104 have a pair of short sides 105 parallel to the first side 211 and a pair of long sides 106 parallel to the second side 212.

[0083] In addition, as Figure 10 shown, in the end portion 2Ad of the second side 212 along the first substrate S11, a second terminal group 20A is provided in the second end portion 22A (indicated by a two-dot chain line) closer to the first side 211 side (or the third side 213 side) than the center of the second side 212. That is, the end portion 2Ad is the end portion on the X1 side in the first substrate S11, and in the portion of the end portion 2Ad, the second end portion 22A indicated by a two-dot chain line is arranged closer to the Y1 side than the center line CL2. The second terminal group 20A is provided in the second end portion 22A. As Figure 10 shown, the second terminal group 20A includes a fifth terminal 201, a sixth terminal 202, a seventh terminal 203, and an eighth terminal 204. The fifth terminal 201, the sixth terminal 202, the seventh terminal 203, and the eighth terminal 204 are arranged in sequence in the X direction from the X1 side to the X2 side. These terminals 201, 202, 203, 204 have a pair of long sides 107 parallel to the first side 211 and a pair of short sides 108 parallel to the second side 212.

[0084] Next, the wirings of the first substrate S11 and the second substrate S12 will be described. It should be noted that, on the front and back surfaces of the substrate, the wirings are provided on the front surface. That is, the surface on which the wirings are provided is regarded as the front surface, and the surface on the opposite side of the front surface is regarded as the back surface.

[0085] As Figure 10 shown, wirings, driving electrodes, and connection portions are provided on the front surface 2Aa of the first substrate S11. It should be noted that the connection portion C1 of the first substrate S11 and the connection portion C3 of the second substrate S12 (refer to Figure 11 ) are electrically connected via a conductive post 58 that can conduct (refer to Figure 8 ). Similarly, the connection portion C2 of the first substrate S11 and the connection portion C4 of the second substrate S12 (refer to Figure 11 ) are electrically connected via a conductive post 58 that can conduct (refer to Figure 8 ).

[0086] The first terminal 101 is electrically connected to the fifth terminal 201 via a wiring 241. A branch point 242 is provided in the middle of the wiring 241, and the wiring extends from the branch point 242 to the connection portion C1.

[0087] The second terminal 102 is electrically connected to the sixth terminal 202 via wirings 243 and 245. It should be noted that a branch point 244 is provided in the wiring 243, and a wiring 246 extends from the branch point 244 to the end 247.

[0088] The third terminal 103 and the seventh terminal 203 are electrically connected via the wiring 248. The fourth terminal 104 and the eighth terminal 204 are electrically connected via the wirings 249 and 251. The wiring 249 extends from the fourth terminal 104 to the X2 side up to the branch point 250. The wiring 251 extends from the branch point 250 to the eighth terminal 204. The wiring extends from the branch point 250 to the connection portion C2.

[0089] Here, the electrodes for driving the liquid crystal will be described. The driving electrodes in the liquid crystal panel 1A include a driving electrode (first driving electrode) E11 and a driving electrode (second driving electrode) E12.

[0090] The driving electrode E11 includes a driving electrode E11A and a driving electrode E11B. The driving electrode E12 includes a driving electrode E12A and a driving electrode E12B.

[0091] A plurality of driving electrodes E11A are connected to the wirings 243 and 246. The driving electrode E11A extends linearly in the Y direction. The driving electrodes E11A are arranged at equal intervals in the X direction.

[0092] A plurality of driving electrodes E11B are connected to the wiring 248. The driving electrode E11B extends linearly in the Y direction. The driving electrodes E11B are arranged at equal intervals in the X direction. It should be noted that the driving electrode E11A and the driving electrode E11B are alternately arranged in the X direction.

[0093] As Figure 11 shown, wirings, driving electrodes, and connection portions are provided on the surface 3Aa of the second substrate S12. It should be noted that Figure 11 the center lines CL1 and CL2 shown correspond to Figure 10 the center lines CL1 and CL2 shown.

[0094] The connection portion C3 is connected to the wirings 342 and 343 via the branch point 341. The wiring 342 extends to the end 348. The wiring 343 extends to the end 349. The connection portion C4 is connected to the wirings 345 and 346 via the branch point 344. The wiring 346 extends to the end 347.

[0095] A plurality of driving electrodes E12A are connected to the wirings 342 and 343. The driving electrode E12A extends linearly in the Y direction. The driving electrodes E12A are arranged at equal intervals in the X direction.

[0096] A plurality of driving electrodes E12B are connected to the wiring 346. The driving electrode E12B extends linearly in the X direction. The driving electrodes E12B are arranged at equal intervals in the Y direction. It should be noted that the driving electrode E12A and the driving electrode E12B are alternately arranged in the Y direction.

[0097] Next, a simple description will be given of the cross-sectional structure of the liquid crystal panel 1A. As Figure 12 shown, the liquid crystal panel 1A includes: a first substrate S11, a second substrate S12, and a liquid crystal layer LC1(60). As Figure 12 shown, the second substrate S12 is disposed on the front surface (Z1 side) of the first substrate S11. A liquid crystal layer LC1 is provided between the second substrate S12 and the first substrate S11. That is, the surface 2Aa of the first substrate S11 and the surface 3Aa of the second substrate S12 are arranged to face each other with the liquid crystal layer LC1 therebetween. It should be noted that the opposite surface of the surface 2Aa of the first substrate S11 is the back surface 2Ab, and the opposite surface of the surface 3Aa of the second substrate S12 is the back surface 3Ab. In addition, as described above, since the area of the second substrate S12 is smaller than the area of the first substrate S11, the third terminal 103 provided on the surface 2Aa of the first substrate S11 is exposed. It should be noted that the insulating layer is provided to prevent the contact of two wirings. In the liquid crystal panel 1A according to the present embodiment, since there is no portion where wirings overlap on the first substrate S11, the insulating layer is not provided.

[0098] Furthermore, as Figure 12 shown, alignment films AL11 and AL12 are laminated on the two substrates and the electrode layers. Specifically, an alignment film AL11 is laminated on the surface 2Aa of the first substrate S11, the driving electrodes E11A, 262, and a part of the upper surface of the wiring 248. In addition, an alignment film AL12 is laminated on the surface 3Aa of the second substrate S12 and the upper surface of the driving electrode E12A. Moreover, the first substrate S11 and the second substrate S12 are bonded by a sealing member 59 surrounding the effective area, and a liquid crystal layer LC1 is filled in the space formed by the sealing member 59.

[0099] (Rotation of the light distribution pattern)

[0100] In the present embodiment, by rotating the four liquid crystal panels 1A about the central axis AX, for example, it is possible to control to have an elliptical light distribution pattern with a major axis rotated by, for example, 45 degrees with respect to the X axis or the Y axis. Hereinafter, a specific description will be given.

[0101] Figure 13 is a schematic diagram showing an example of the rotation of the light distribution pattern. The light distribution pattern 600 is an elliptical light distribution pattern with the major axis along the Y axis. This is, for example, the light distribution pattern observed from the Z1 side in the case where, in a part or all of the four liquid crystal panels 1A, there is no potential difference between adjacent electrodes of a plurality of electrodes extending in the Y direction and arranged in the X direction, but there is a potential difference between adjacent electrodes of a plurality of electrodes extending in the X direction and arranged in the Y direction. It should be noted that the ratio of the Y axis to the X axis of this elliptical shape depends on this potential difference.

[0102] The light distribution pattern 601 is an elliptical light distribution pattern with its major axis along the X-axis. This is, for example, the light distribution pattern observed from the Z1 side when in one or all of the four liquid crystal panels 1A, there is no potential difference between adjacent electrodes of a plurality of electrodes extending in the Y direction and arranged in the X direction, but there is a potential difference between electrodes of a plurality of adjacent electrodes extending in the X direction and arranged in the Y direction. It should be noted that the ratio of the Y-axis to the X-axis of this elliptical shape depends on this potential.

[0103] The light distribution pattern 602 is an elliptical light distribution pattern with its major axis inclined 45 degrees counterclockwise (left turn direction) with respect to the X-axis. This is obtained, for example, by rotating all four liquid crystal panels 1A counterclockwise (left turn direction) by 45 degrees about the central axis AX from the state of the light distribution pattern 601.

[0104] The light distribution pattern 603 is an elliptical light distribution pattern with its major axis inclined 45 degrees counterclockwise (left turn direction) with respect to the Y-axis. This is obtained, for example, by rotating all four liquid crystal panels 1A counterclockwise (left turn direction) by 45 degrees about the central axis AX from the state of the light distribution pattern 600.

[0105] Next, the operation mode of general light diffusion will be described.

[0106] (Light diffusion in one liquid crystal panel)

[0107] Figure 14A is a cross-sectional view of the liquid crystal panel, showing the alignment state of liquid crystal molecules in a state where no voltage is applied to the electrodes for driving the liquid crystal. Figure 14B is a cross-sectional view of the liquid crystal panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the electrodes for driving the liquid crystal. Figure 14C is a diagram showing the waveform of the control signal applied to the electrodes for driving the liquid crystal. Figure 15A is a schematic perspective view of the liquid crystal panel, showing the arrangement of the first driving electrode and the second driving electrode. Figure 15B is a schematic perspective view of the liquid crystal panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the second driving electrode. It should be noted that Figure 14A and Figure 14B is from Figure 15A the view of observing the liquid crystal panel in the direction of arrow 610 in Figure 15B is from Figure 15A the view of observing the liquid crystal panel in the direction of arrow 620 in

[0108] Figure 14AIt is shown that in the first liquid crystal panel 10, the alignment treatment directions of the first alignment film AL11 and the second alignment film AL12 are different. Specifically, the first alignment film AL11 is subjected to alignment treatment in the X direction, and the second alignment film AL12 is subjected to alignment treatment in the Y direction. Thus, the alignment direction of the first alignment film AL11 and the alignment direction of the second alignment film AL12 are substantially orthogonal. Thus, when viewed from the Z direction, the orientation of the initial light distribution on the first substrate S11 side in the first liquid crystal panel 10 is orthogonal (crossed) to the orientation of the initial light distribution on the second substrate S12 side. It should be noted that the alignment treatment can be a rubbing treatment or a photoalignment treatment. In addition, the alignment direction of the alignment film can be set within a range of 90 degrees ± 10 degrees with respect to the extending direction of the driving electrode E11.

[0109] Since the alignment direction of the first alignment film AL11 and the alignment direction of the second alignment film AL12 are substantially orthogonal, the liquid crystal molecules 60A in the first liquid crystal layer LC1 are aligned in a state where the long axis direction of the liquid crystal molecules 60A is twisted by 90 degrees from the first alignment film AL11 to the second alignment film AL12 without being affected by an external electric field. Figure 14A It shows a state where no voltage is applied to the driving electrode E11A and the driving electrode E11B. Therefore, as Figure 14A shown, the long axis direction of the liquid crystal molecules 60A is twisted by 90 degrees from the first alignment film AL11 to the second alignment film AL12 and aligned.

[0110] It should be noted that Figure 14A It shows an example in which a positive twisted nematic liquid crystal (TN liquid crystal) is used as the first liquid crystal layer LC1, for example, and the liquid crystal molecules 60A are aligned in a direction in which the long axis is the same as the alignment direction of the alignment film. The liquid crystal layer 60 preferably contains a chiral agent that imparts twist to the liquid crystal molecules 60A.

[0111] As Figure 14C shown, a low-level voltage VL is applied to the driving electrode E11A, and a high-level voltage VH is applied to the driving electrode E11B. In other words, pulse voltages with the same amplitude and opposite polarities during the same period are applied to the two driving electrodes E11A and E11B respectively. In this state, as Figure 14B shown, a lateral electric field is generated between the driving electrode E11A and the driving electrode E11B. As Figure 14B shown, the liquid crystal molecules 60A on the first substrate S11 side are affected by the lateral electric field, and the alignment direction changes. For example, the alignment of the liquid crystal molecules 60A on the first substrate S11 side changes in such a way that the long axis direction faces a direction parallel to the direction of the electric field.

[0112] The values of the low-level voltage VL and the high-level voltage VH applied to the drive electrodes E11A and E11B can be appropriately set. For example, 0V is applied as the low-level voltage VL1, and a voltage of 5V or more and 30V or less is applied as the high-level voltage VH1, for example. A voltage in which the low-level voltage VL and the high-level voltage VH are periodically and alternately applied to the drive electrodes E11A and E11B (see Figure 14C ).

[0113] By alternately applying the low-level voltage VL and the high-level voltage VH to the adjacent electrodes E11A and the drive electrodes E11B on the same substrate, an alternating electric field is generated, and deterioration of the first liquid crystal layer LC1 can be suppressed. It should be noted that the frequency of the voltage applied to the drive electrodes E11A and E11B only needs to be a frequency at which the liquid crystal molecules can follow the change of the electric field. For example, it only needs to be 15Hz or more and 100Hz or less.

[0114] Here, it is known that the refractive index of a liquid crystal changes according to the alignment state. As Figure 14A shows, in the OFF state where no electric field acts on the first liquid crystal layer LC1, the long axis direction of the liquid crystal molecules 60A is oriented horizontally with respect to the surface of the substrate, and is oriented in a state of being twisted by 90 degrees from the first substrate S11 side to the second substrate S12 side. The first liquid crystal layer LC1 has an almost uniform refractive index distribution in this alignment state. Therefore, although the S wave of the light incident on the first liquid crystal panel 10 and the P wave orthogonal to the S wave are optically rotated by the initial alignment of the liquid crystal molecules 60A, they are hardly refracted (or scattered) and pass through the first liquid crystal layer LC1 in the Z direction. It should be noted that optical rotation means that during the process of the polarization component passing through the liquid crystal layer 60, by changing the orientation of polarization, hereinafter, during the process of passing through the liquid crystal layer 60 of each liquid crystal panel 1A, the P polarization component (P wave) changes to the S polarization component (S wave), and the S polarization component (S wave) changes to the P polarization component (P wave).

[0115] On the other hand, as Figure 14B shows, in the ON state where an electric field is formed by applying a voltage to the drive electrodes E11A and the drive electrodes E11B, when the first liquid crystal layer LC1 has positive dielectric anisotropy, the liquid crystal molecules are oriented with their long axes along the electric field. As a result, as Figure 14B shows, in the first liquid crystal layer LC1, there are formed: a region where the liquid crystal molecules 60A rise almost vertically above the drive electrodes E11A and the drive electrodes E11B, a region where the liquid crystal molecules are oriented obliquely along the distribution of the electric field between the drive electrodes E11A and the drive electrodes E11B, and a region where the initial alignment state is maintained in a region far from the drive electrodes E11A and the drive electrodes E11B, etc.

[0116] As Figure 14B shown, between the electrodes of the drive electrodes E11A and E11B, the major axis of the liquid crystal molecules 60A is oriented in a convex arc shape along the direction of the electric field generation. That is, as Figure 14A and as Figure 14B shown, the direction of the initial orientation of the liquid crystal molecules 60A is the same as the direction of the lateral electric field generated between the drive electrodes E11A and E11B. As Figure 14B schematically shown, the orientation direction of the liquid crystal molecules 60A located approximately at the center between the two electrodes hardly changes, but the liquid crystal molecules located on each electrode side starting from the central part are oriented by tilting (skewing) in the normal direction with respect to the surface of the first substrate S11 according to the electric field intensity distribution. Therefore, if the liquid crystal on the first substrate S11 side is regarded as a whole, the liquid crystal molecules 60A are oriented in an arc shape between the drive electrodes E11A and E11B.

[0117] Thereby, an arc-shaped dielectric constant distribution is formed in the first liquid crystal layer LC1, and the incident light (the polarization component parallel to the direction of the initial orientation of the liquid crystal molecules 60A) diffuses radially. In addition, as Figure 15B shown, on the second substrate S12 side, the same phenomenon occurs by the drive electrodes E12A and E12B, and the polarization component parallel to the direction of the initial orientation of the liquid crystal molecules 60A in the incident light diffuses radially. That is, for example, when the S wave diffuses on the first substrate S11 side in the liquid crystal layer 60, the P wave diffuses on the second substrate S12 side in the liquid crystal layer 60. In addition, for example, when the P wave diffuses on the first substrate S11 side in the liquid crystal layer 60, the S wave diffuses on the second substrate S12 side in the liquid crystal layer 60.

[0118] Moreover, in the present embodiment, the thickness of the liquid crystal layer 60 is thick enough, and the cell gap G between the substrates is about 15 μm to 50 μm. Therefore, the diffusion of different polarization components can be independently controlled on the first substrate S11 side and the second substrate S12 side, respectively. It should be noted that since the liquid crystal molecules 60A have refractive index anisotropy Δn, the conductive liquid crystal layer 60 has a refractive index distribution or retardation distribution corresponding to the orientation state of the liquid crystal molecules 60A. When the thickness of the liquid crystal layer 60 is d, the retardation here is represented by Δn·d. In the conductive state, when the S wave or the P wave passes through the liquid crystal layer 60, it is scattered by the refractive index distribution of the liquid crystal layer 60.

[0119] (Diffusion of light in two stacked liquid crystal panels)

[0120] Figure 16This is a diagram schematically showing the state in which P-waves and S-waves spread when a second liquid crystal panel is laminated on a first liquid crystal panel 10. It should be noted that the drive electrodes in the second liquid crystal panel 20 include a drive electrode (first drive electrode) E21 and a drive electrode (second drive electrode) E22. Further, the drive electrode E21 includes a drive electrode E21A and a drive electrode E21B, and the drive electrode E22 includes a drive electrode E22A and a drive electrode E22B. The configuration of the second liquid crystal panel 20 is the same as that of the first liquid crystal panel 10, and the second liquid crystal panel 20 is laminated directly (the rotation angle with respect to the Z-axis direction is 0°) on the first liquid crystal panel 10. It should be noted that a configuration in which the second liquid crystal panel 20 is laminated on the first liquid crystal panel 10 in a state rotated 180 degrees in the Z-axis direction may also be adopted.

[0121] As Figure 16 shown, the S-wave parallel to the X-axis incident on the first liquid crystal panel 10 is optically rotated when passing through the first liquid crystal layer LC1, and becomes a polarization component parallel to the Y-axis on the second substrate S12 side. That is, the S-wave has a polarization axis along the X-axis direction on the first substrate S11 side, but the polarization axis gradually changes during the process of passing through the first liquid crystal layer LC1 in the Z direction, and becomes a P-wave having a polarization axis along the Y-axis direction on the second substrate S12 side, and is emitted from the second substrate S12 side. Thus, the S-wave on the first substrate S11 side is optically rotated during the process of passing through the liquid crystal layer 60, and as a result, becomes a P-wave on the second substrate S12 side.

[0122] Here, since the polarization axis of the S-wave on the first substrate S11 side is parallel to the alignment direction of the liquid crystal molecules 60A in the first liquid crystal layer LC1 on the first substrate S11 side, the S-wave spreads in the X-axis direction according to the change in the refractive index distribution of the liquid crystal molecules 60A. In addition, the P-wave on the second substrate S12 side spreads in the Y-axis direction according to the change in the refractive index distribution of the liquid crystal molecules 60A.

[0123] In contrast, since the polarization axis of the P-wave on the first substrate S11 side is orthogonal to the alignment direction of the liquid crystal molecules 60A in the first substrate S11 side of the first liquid crystal layer LC1, the P-wave is not affected by the refractive index distribution of the liquid crystal molecules 60A and passes through without spreading. In addition, since the S-wave in the second substrate S12 side is also orthogonal to the alignment direction of the liquid crystal molecules 60A, the S-wave is not affected by the refractive index distribution of the liquid crystal molecules 60A and passes through without spreading. That is, the P-wave incident on the first liquid crystal panel 10 is optically rotated during the process of passing through the first liquid crystal panel 10 and as a result becomes an S-wave, and is emitted from the second substrate S12 without being diffused by the first liquid crystal layer LC.

[0124] When viewed from the Z direction, the orientation of the initial light distribution on the side of the first substrate S21 in the second liquid crystal panel 20 is orthogonal (crosses) to the orientation of the initial light distribution on the side of the second substrate S22. When viewed from the Z direction, the orientation of the initial light distribution on the side of the first substrate S21 in the second liquid crystal panel 20 is the same as the orientation of the initial light distribution on the side of the first substrate S11 in the first liquid crystal panel 10.

[0125] The second liquid crystal layer LC2 of the second liquid crystal panel 20 also has the same refractive index distribution as the first liquid crystal layer LC1 of the first liquid crystal panel 10. Therefore, substantially the same phenomenon as in the first liquid crystal panel 10 also occurs in the second liquid crystal panel 20. On the other hand, since the polarization axes of the initial S wave and P wave are switched by passing through the first liquid crystal panel 10, the polarization components affected by the refractive index distribution in the second liquid crystal layer LC2 are also switched. That is, in the process of passing through the second liquid crystal panel 20, the polarization axis of the initial S wave changes from the Y-axis direction to the X-axis direction again, but does not spread. On the other hand, the polarization axis of the initial P wave changes from the X-axis direction to the Y-axis direction again and spreads due to the influence of the refractive index distribution of the second liquid crystal layer LC2. That is to say, the initial S wave spreads in the first liquid crystal panel 10 but does not spread in the second liquid crystal panel 20. The initial P wave does not spread in the first liquid crystal panel 10 but spreads in the second liquid crystal panel 20.

[0126] (Diffusion of light in the four stacked liquid crystal panels)

[0127] Figure 17 It is a diagram schematically showing the state of diffusion of P waves and S waves using the four liquid crystal panels according to the first embodiment.

[0128] Figure 17 With respect to Figure 16 The third liquid crystal panel 30 and the fourth liquid crystal panel 40 are further added to the two first liquid crystal panels 10 and the second liquid crystal panel 20 shown. That is, in the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30, and the fourth liquid crystal panel 40, horizontal electric fields are formed on both sides of the two drive electrode sides. It should be noted that the drive electrodes in the third liquid crystal panel 30 include a drive electrode (first drive electrode) E31 and a drive electrode (second drive electrode) E32. Further, the drive electrode E31 includes a drive electrode E31A and a drive electrode E31B, and the drive electrode E32 includes a drive electrode E32A and a drive electrode E32B. In addition, the drive electrodes in the fourth liquid crystal panel 40 include a drive electrode (first drive electrode) E41 and a drive electrode (second drive electrode) E42. Further, the drive electrode E41 includes a drive electrode E41A and a drive electrode E41B, and the drive electrode E42 includes a drive electrode E42A and a drive electrode E42B.

[0129] The structures of these third liquid crystal panels 30 and fourth liquid crystal panels 40 are the same as that of the first liquid crystal panel 10, and these third liquid crystal panels 30 and fourth liquid crystal panels 40 are stacked in a state of being rotated by an angle of 90° with respect to the second liquid crystal panel 20 in the Z-axis direction. It should be noted that a structure in which either one or both of the third liquid crystal panel 30 and the fourth liquid crystal panel 40 are stacked in a state of being rotated by 270 degrees with respect to the first liquid crystal panel 10 in the Z-axis direction can also be adopted.

[0130] Hereinafter, with reference to Figure 17 it will be described. It should be noted that Figure 17 (diffused light 1X) shown in the table of means that the polarization component has diffused once in the X-axis direction before reaching this position, and (diffused light 1X1Y) means that the polarization component has diffused once in the X-axis direction and also diffused once in the Y-axis direction before reaching this position. The same applies to others.

[0131] It should be noted that when viewed from the Z direction, the orientation of the initial light distribution on the first substrate S31 side in the third liquid crystal panel 30 is orthogonal (crosses) to the orientation of the initial light distribution on the second substrate S32 side. When viewed from the Z direction, the orientation of the initial light distribution on the first substrate S41 side in the fourth liquid crystal panel 40 is orthogonal (crosses) to the orientation of the initial light distribution on the second substrate S42 side. The orientation of the initial light distribution on the first substrate S31 side in the third liquid crystal panel 30 is the same as the orientation of the initial light distribution on the first substrate S41 side in the fourth liquid crystal panel 40. In addition, the orientation of the initial light distribution on the first substrate S31 side in the third liquid crystal panel 30 and the orientation of the initial light distribution on the first substrate S41 side in the fourth liquid crystal panel 40 are orthogonal (crosses) to the orientation of the initial light distribution on the first substrate S11 side in the first liquid crystal panel 10 and the orientation of the initial light distribution on the first substrate S21 side in the second liquid crystal panel 20.

[0132] As described above, in the incident light incident on the first liquid crystal panel 10, before the S wave is incident on the first liquid crystal panel 10 and exits from the second liquid crystal panel 20, it is optically rotated once to a P wave and then optically rotated again to an S wave, and diffuses once in each of the X-axis direction and the Y-axis direction in the second liquid crystal panel 20.

[0133] In addition, in the incident light incident on the first liquid crystal panel 10, before the P wave is incident on the first liquid crystal panel 10 and exits from the second liquid crystal panel 20, it is optically rotated once to an S wave and then optically rotated again to a P wave, and diffuses once in each of the X-axis direction and the Y-axis direction in the first liquid crystal panel 10.

[0134] In the third liquid crystal panel 30, the long side direction of the driving electrode E31 crosses the driving electrode E11 of the first liquid crystal panel 10 and the driving electrode E21 of the second liquid crystal panel 20 at an angle of 90° ± 10°. The long side direction of the driving electrode E32 crosses the driving electrode E12 of the first liquid crystal panel 10 and the driving electrode E22 of the second liquid crystal panel 20 at an angle of 90° ± 10°. Similarly, in the fourth liquid crystal panel 40, the long side direction of the driving electrode E41 crosses the driving electrode E11 of the first liquid crystal panel 10 and the driving electrode E21 of the second liquid crystal panel 20 at an angle of 90° ± 10°, and the long side direction of the driving electrode E42 crosses the driving electrode E12 and the driving electrode E22 at an angle of 90° ± 10°. Therefore, in these third and fourth liquid crystal panels 30 and 40, the phenomena generated in the first liquid crystal panel 10 and the second liquid crystal panel 20 are reversed for S-waves and P-waves.

[0135] (Regarding the S-wave incident on the third liquid crystal panel 30)

[0136] That is, when the S-wave emitted from the second liquid crystal panel 20 (the S-wave incident on the first liquid crystal panel 10) is incident on the third liquid crystal panel 30, the polarization direction of this S-wave becomes parallel to the long axis direction of the liquid crystal molecules on the first substrate S31 side of the third liquid crystal layer LC3. Here, since the refractive index distribution of the liquid crystal molecules on the first substrate S31 side changes due to the electric field generated by the driving electrode E31, this S-wave diffuses in the Y-axis direction. In addition, during the process of this diffused S-wave traveling from the first substrate S31 side to the second substrate S32 side of the third liquid crystal layer LC3, it is optically rotated by 90° according to the twisted orientation of the liquid crystal molecules. As a result, the S-wave is converted back into a P-wave again. In addition, the polarization direction of this P-wave is parallel to the long axis direction of the liquid crystal molecules on the second substrate S32 side. Here, since the refractive index distribution of the liquid crystal molecules 60A on the second substrate S32 side changes due to the electric field generated by the driving electrode E32, the P-wave is further diffused in the Y-axis direction under the influence of the refractive index distribution of these liquid crystal molecules and then emitted. That is, the S-wave incident on the third liquid crystal panel 30 is converted into a P-wave while passing through the third liquid crystal panel 30, and at the same time, it diffuses once again in the X-axis direction and the Y-axis direction respectively.

[0137] The P wave is emitted from the third liquid crystal panel 30 and incident on the fourth liquid crystal panel 40. The polarization direction of the P wave is a direction crossing the long axis direction of the liquid crystal molecules 60A on the side of the first substrate S41 of the fourth liquid crystal layer LC4. Therefore, although the refractive index distribution of the liquid crystal molecules 60A on the side of the first substrate S41 changes due to the electric field generated by the driving electrode E41, the P wave does not spread and heads towards the second substrate S42 side as it is. In addition, during the process of the P wave traveling from the first substrate S41 side to the second substrate S42 side of the fourth liquid crystal layer LC4, it is optically rotated by 90 degrees according to the twisted orientation of the liquid crystal molecules 60A. Thus, the P wave is converted into an S wave. In addition, the polarization direction of the S wave is a direction crossing the long axis direction of the liquid crystal molecules on the second substrate S42 side. Therefore, although the refractive index distribution of the liquid crystal molecules 60A on the second substrate S42 side changes due to the electric field generated by the driving electrode E12, the S wave passes through without being affected by it. That is, the P wave is converted into an S wave during the process of passing through the fourth liquid crystal panel 40, and on the other hand, it passes through the fourth liquid crystal panel 40 without diffusion or the like.

[0138] Thus, before the S wave incident on the third liquid crystal panel 30 is emitted from the fourth liquid crystal panel 40, it is converted into a P wave once and then into an S wave again, and diffuses once in each of the X-axis direction and the Y-axis direction of the third liquid crystal panel 30.

[0139] (Regarding the P wave incident on the third liquid crystal panel 30)

[0140] The polarization direction of the P wave incident on the third liquid crystal panel 30 is a direction crossing (orthogonal direction) the long axis direction of the liquid crystal molecules 60A on the side of the first substrate S31 of the third liquid crystal layer LC3. Therefore, although the refractive index distribution of the liquid crystal molecules 60A on the side of the first substrate S31 changes due to the electric field generated by the driving electrode E31, the P wave does not spread and heads towards the second substrate S32 side as it is. In addition, during the process of the P wave traveling from the first substrate S31 side to the second substrate S32 side of the third liquid crystal layer LC3, it is optically rotated by 90 degrees according to the twisted orientation of the liquid crystal molecules 60A. Thus, the P wave is converted into an S wave. In addition, the polarization direction of the S wave is a direction crossing the long axis direction of the liquid crystal molecules 60A on the second substrate S32 side. Therefore, although the refractive index distribution of the liquid crystal molecules 60A on the second substrate S32 side changes due to the electric field generated by the driving electrode E32, the S wave passes through without being affected by it. That is, the P wave incident on the third liquid crystal panel 30 is converted into an S wave during the process of passing through the third liquid crystal panel 30, but passes through without diffusion.

[0141] When the S wave passes through the third liquid crystal panel 30 and is incident on the fourth liquid crystal panel 40, the polarization direction of the S wave becomes parallel to the long axis direction of the liquid crystal molecules 60A on the first substrate S41 side of the fourth liquid crystal layer LC4. Since the refractive index distribution of the liquid crystal molecules 60A on the first substrate S41 side of the fourth liquid crystal panel 40 changes due to the electric field generated by the drive electrode E41, the S wave diffuses in the X-axis direction. In addition, during the process of the diffused S wave traveling from the first substrate S41 side of the fourth liquid crystal layer LC4 to the second substrate S42 side, it is optically rotated by 90 degrees according to the twisted orientation of the liquid crystal molecules 60A. As a result, the S wave is converted back into a P wave again. The polarization direction of this P wave is parallel to the long axis direction of the liquid crystal molecules 60A on the second substrate S42 side. Here, since the refractive index distribution of the liquid crystal molecules 60A on the second substrate S42 side changes due to the electric field generated by the drive electrode E42, the P wave is further diffused in the Y-axis direction under the influence of the refractive index distribution of the liquid crystal molecules 60A and exits from the second substrate S42 side.

[0142] Thus, before the P wave incident on the third liquid crystal panel 30 exits from the fourth liquid crystal panel 40, it is converted into an S wave once and then converted back into a P wave again, and is diffused once in each of the X-axis direction and the Y-axis direction of the fourth liquid crystal panel 40.

[0143] (Summary of the diffusion of light passing through the first liquid crystal panel 10 to the fourth liquid crystal panel 40)

[0144] As described above, during the period from when the S wave emitted from the LED 110 is incident on the first liquid crystal panel 10 until it exits from the fourth liquid crystal panel 40, it is diffused twice in each of the X-axis direction and the Y-axis direction. In addition, during the period from when the P wave emitted from the LED 110 is incident on the first liquid crystal panel 10 until it exits from the fourth liquid crystal panel 40, it is diffused twice in each of the X-axis direction and the Y-axis direction.

[0145] (Overall configuration of the lighting device)

[0146] Figure 18 It is a schematic diagram showing the overall configuration of the liquid crystal panel, relay substrate, and control substrate according to the first embodiment. Figure 19A It is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four liquid crystal panels. Figure 19B It is a diagram for overall explaining the polarization wave, the diffusion direction of the polarization wave, and the potential of the terminals acting in each of the four liquid crystal panels.

[0147] As Figure 18As shown in the figure, the lighting device 100 according to the first embodiment includes: four liquid crystal panels 1A, two relay substrates 4A and 4B, and two control substrates 5A and 5B. The control substrate 5A is electrically connected to the relay substrate 4A via a wire harness 210, and the wire harness 210 has signal lines 713, 714, 715, and 716. The relay substrate 4A is electrically connected to the first liquid crystal panel 10 via a flexible printed circuit board 200, and the flexible printed circuit board 200 has signal lines 701, 702, 703, and 704. The relay substrate 4A is electrically connected to the third liquid crystal panel 30 via a flexible printed circuit board 200, and the flexible printed circuit board 200 has signal lines 705, 706, 707, and 708. The control substrate 5B is electrically connected to the relay substrate 4B via a wire harness 210, and the wire harness 210 has signal lines 733, 734, 735, and 736. The relay substrate 4B is electrically connected to the second liquid crystal panel 20 via a flexible printed circuit board 200, and the flexible printed circuit board 200 has signal lines 721, 722, 723, and 724. The relay substrate 4B is electrically connected to the fourth liquid crystal panel 40 via a flexible printed circuit board 200, and the flexible printed circuit board 200 has signal lines 725, 726, 727, and 728.

[0148] Accordingly, the four liquid crystal panels 1A are the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30, and the fourth liquid crystal panel 40. The first liquid crystal panel 10 and the third liquid crystal panel 30 are electrically connected to the relay substrate 4A via eight signal lines. The second liquid crystal panel 20 and the fourth liquid crystal panel 40 are electrically connected to the relay substrate 4B via eight signal lines. The relay substrate 4A is electrically connected to the control substrate 5A via four signal lines. The relay substrate 4B is electrically connected to the control substrate 5B via four signal lines. Details will be described below. It should be noted that in Figure 18 each liquid crystal panel, only the first substrate is shown, and the illustration of the second substrate is omitted. However, as described above, the second substrate is provided with drive electrodes in a direction intersecting the orientation of the drive electrodes of the first substrate.

[0149] As Figure 18As shown, connectors 631, 632, and 633 are provided on the relay substrate 4A. As described above, on the first liquid crystal panel 10, there are provided: a first terminal 101 corresponding to the electrode E12A of the second substrate, a second terminal 102 corresponding to the electrode E11A of the first substrate, a third terminal 103 corresponding to the electrode E11B of the first substrate, and a fourth terminal 104 corresponding to the electrode E12B of the second substrate. The first terminal 101 is connected to the connector 632 via the signal line 701. The second terminal 102 is connected to the connector 632 via the signal line 702. The third terminal 103 is connected to the connector 632 via the signal line 703. The fourth terminal 104 is connected to the connector 632 via the signal line 704.

[0150] In addition, on the third liquid crystal panel 30, there are provided a fifth terminal 201, a sixth terminal 202, a seventh terminal 203, and an eighth terminal 204. The fifth terminal 201 is connected to the connector 631 via the signal line 705. The sixth terminal 202 is connected to the connector 631 via the signal line 706. The seventh terminal 203 is connected to the connector 631 via the signal line 707. The eighth terminal 204 is connected to the connector 631 via the signal line 708.

[0151] The signal line 701 and the signal line 707 are electrically connected to the signal line 709 via the connectors 631 and 632. That is, two signal lines are connected to one signal line on the relay substrate 4A via the connectors 631 and 632. The same applies to the other signal lines, where two are connected to one on the relay substrates 4A and 5B. Specifically, the signal line 702 and the signal line 708 are electrically connected to the signal line 710 via the connectors 631 and 632. The signal line 703 and the signal line 705 are electrically connected to the signal line 711 via the connectors 631 and 632. The signal line 704 and the signal line 706 are electrically connected to the signal line 712 via the connectors 631 and 632.

[0152] Moreover, one signal line in the relay substrate 4A is electrically connected to one signal line in the control substrate 5A via the connector 633. Specifically, the signal line 709 in the relay substrate 4A is connected to the connector 637 of the control substrate 5A via the signal line 713 of the harness 210. The signal line 710 in the relay substrate 4A is connected to the connector 637 of the control substrate 5A via the signal line 714 of the harness 210. The signal line 711 in the relay substrate 4A is connected to the connector 637 of the control substrate 5A via the signal line 715 of the harness 210. The signal line 712 in the relay substrate 4A is connected to the connector 637 of the control substrate 5A via the signal line 716 of the harness 210.

[0153] Next, the potentials of the signal lines will be described. Signal lines 702, 708, 710, and 714 are at potential A. Signal lines 701, 707, 709, and 713 are at potential B. Signal lines 704, 706, 712, and 716 are at potential C. Signal lines 703, 705, 711, and 715 are at potential D.

[0154] As Figure 18 shown, connectors 634, 635, and 636 are provided on the relay substrate 4B. As described above, the first terminal 101, the second terminal 102, the third terminal 103, and the fourth terminal 104 are provided on the second liquid crystal panel 20. The first terminal 101 is connected to the connector 634 via the signal line 721. The second terminal 102 is connected to the connector 634 via the signal line 722. The third terminal 103 is connected to the connector 634 via the signal line 723. The fourth terminal 104 is connected to the connector 634 via the signal line 724.

[0155] In addition, a fifth terminal 201, a sixth terminal 202, a seventh terminal 203, and an eighth terminal 204 are provided on the fourth liquid crystal panel 40. The fifth terminal 201 is connected to the connector 635 via the signal line 725. The sixth terminal 202 is connected to the connector 635 via the signal line 726. The seventh terminal 203 is connected to the connector 635 via the signal line 727. The eighth terminal 204 is connected to the connector 635 via the signal line 728.

[0156] The signal line 721 and the signal line 727 are electrically connected to the signal line 729 via the connectors 634 and 635. That is, two signal lines are connected to one signal line via the connectors 634 and 635. The same applies to the other signal lines, with two connected to one. Specifically, the signal line 722 and the signal line 728 are electrically connected to the signal line 730 via the connectors 634 and 635. The signal line 723 and the signal line 725 are electrically connected to the signal line 731 via the connectors 634 and 635. The signal line 724 and the signal line 726 are electrically connected to the signal line 732 via the connectors 634 and 635.

[0157] Furthermore, one signal line on the relay substrate 4B is electrically connected to one signal line on the control substrate 5B via the connector 636. Specifically, the signal line 729 on the relay substrate 4B is electrically connected to the signal line 733 on the control substrate 5B. The signal line 730 on the relay substrate 4B is electrically connected to the signal line 734 on the control substrate 5B. The signal line 731 on the relay substrate 4B is electrically connected to the signal line 735 on the control substrate 5B. The signal line 732 on the relay substrate 4B is electrically connected to the signal line 736 on the control substrate 5B.

[0158] Next, the potentials of the signal lines will be described. The signal lines 722, 728, 730, and 734 are at potential A. The signal lines 721, 727, 729, and 733 are at potential B. The signal lines 724, 726, 732, and 736 are at potential C. The signal lines 723, 725, 731, and 735 are at potential D.

[0159] As Figure 19A shown, in the lighting device 100, the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30, and the fourth liquid crystal panel 40 are stacked in order starting from the side closer to the LED 110.

[0160] In the first substrate S11 of the first liquid crystal panel 10, as shown by the hollow arrows, the driving electrodes E11 extend in the Y direction, and in the second substrate S12, as shown by the hollow arrows, the driving electrodes E12 extend in the X direction.

[0161] The second liquid crystal panel 20 is rotated 180 degrees clockwise (right turn direction) around the central axis AX (refer to Figure 4 ) with respect to the first liquid crystal panel 10. In the first substrate S21 of the second liquid crystal panel 20, as shown by the hollow arrows, the driving electrodes E21 extend in the Y direction, and in the second substrate S22, as shown by the hollow arrows, the driving electrodes E22 extend in the X direction.

[0162] The third liquid crystal panel 30 is rotated 270 degrees clockwise (right turn direction) around the central axis AX (refer to Figure 4 ) with respect to the first liquid crystal panel 10. In the first substrate S31 of the third liquid crystal panel 30, as shown by the hollow arrows, the driving electrodes E31 extend in the X direction, and in the second substrate S32, as shown by the hollow arrows, the driving electrodes E32 extend in the Y direction.

[0163] The fourth liquid crystal panel 40 is rotated 90 degrees clockwise (right turn direction) around the central axis AX (refer to Figure 4 ) with respect to the first liquid crystal panel 10. In the first substrate S41 of the fourth liquid crystal panel 40, as shown by the hollow arrows, the driving electrodes E41 extend in the X direction, and in the second substrate S42, as shown by the hollow arrows, the driving electrodes E42 extend in the Y direction.

[0164] Next, taking the first liquid crystal panel 10 as an example, the content of Figure 19B will be described. In the terminal 101 of the first liquid crystal panel 10, the substrate is the second substrate. This means that as referred to Figure 10 and Figure 11As described above, the terminal 101 is connected from the connection portion C1 of the first substrate S11 through the conductive column 58 (see Figure 8 ) and the connection portion C3 of the second substrate S12 (refer to Figure 11 ) and finally electrically connected to the driving electrode E12A of the second substrate S12. The direction of the electrode is the X direction, which means that the direction in which the driving electrode E12A extends is the X direction. Figure 18 As shown in FIG. 1 , the potential is the B potential, which means that the potential of the terminal 101 of the first liquid crystal panel 10 is the B potential. Figure 17 As described in the above, the light diffusion direction is the Y direction, which means that on the second substrate S12 side of the first liquid crystal panel 10, the S wave (more specifically, the S wave obtained by optical rotation of the incident P wave) diffuses in the Y direction. The same applies to other panels and substrates. It should be noted that, as described later, Figure 22 as well as Figure 24 As explained in detail in , the effective polarization means the diffuse polarized wave in the P wave or S wave.

[0165] (light distribution pattern)

[0166] Next, the light distribution pattern will be described. Figure 20A This is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a narrow light distribution pattern. Figure 20B This is an image showing a light distribution pattern of narrow light distribution. Figure 21A This is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a light distribution pattern of horizontal line light distribution. Figure 21B This is an image showing a light distribution pattern of horizontal line light distribution. Figure 22 This is a diagram schematically illustrating a state in which a light distribution pattern of horizontal light distribution is formed by four liquid crystal panels. Figure 23A This is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a vertical line light distribution pattern. Figure 23B This is an image showing a light distribution pattern of vertical line light distribution. Figure 24 This is a diagram schematically illustrating a state in which a light distribution pattern of vertical line light distribution is formed by four liquid crystal panels. Figure 25A This is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in an elliptical light distribution pattern. Figure 25B This is an image showing a light distribution pattern of an elliptical light distribution. Figure 26A This is a diagram showing the waveform of a control signal applied to an electrode for driving liquid crystal in a circular light distribution pattern. Figure 26B This is an image showing a light distribution pattern of circular light distribution.

[0167] (1) Light distribution pattern for narrow light distribution

[0168] Reference Figure 20A as well as Figure 20B, illustrates the light distribution pattern of narrow light distribution. As Figure 20A shown, the potentials A, B, C, and D are all 0V. That is, on any electrode of the drive electrodes of the four liquid crystal panels, since no current flows, the potential is 0V and no lateral electric field is generated. Therefore, in the light incident from the first liquid crystal panel 10 and emitted from the fourth liquid crystal panel 40, neither the P wave nor the S wave spreads. Therefore, as Figure 20B shown, the light incident from the first liquid crystal panel 10 is emitted from the fourth liquid crystal panel 40 in the state of the original light distribution pattern.

[0169] (2) Horizontal light distribution pattern

[0170] The horizontal light distribution pattern is a linear light distribution pattern that extends relatively long in the horizontal direction (in the Y direction in this embodiment) (refer to Figure 21B ). As Figure 21A shown, the low-level voltage VL of potential B and potential C is -aV, and the high-level voltage VH is aV. In addition, potentials A and D are 0V. In other words, potentials B and C are pulse voltages with a first amplitude and opposite polarities during the same period. Therefore, pulse voltages are applied to the drive electrode E12 of the first liquid crystal panel 10, the drive electrode E31 of the third liquid crystal panel 30, the drive electrode E22 of the second liquid crystal panel 20, and the drive electrode E41 of the fourth liquid crystal panel 40.

[0171] Specifically, pulse voltages with a first amplitude and opposite polarities during the same period are applied to the drive electrode E12A and the drive electrode E12B respectively. Pulse voltages with a first amplitude and opposite polarities during the same period are applied to the drive electrode E31A and the drive electrode E31B respectively. Pulse voltages with a first amplitude and opposite polarities during the same period are applied to the drive electrode E22A and the drive electrode E22B respectively. Pulse voltages with a first amplitude and opposite polarities during the same period are applied to the drive electrode E41A and the drive electrode E41B respectively. Moreover, the operation mode of light diffusion is as Figure 22 shown. On the left side of Figure 22 , shading is added to the drive electrodes that form the electric field.

[0172] As Figure 22As shown, the S wave incident on the first liquid crystal panel 10 does not spread during the passage through the first liquid crystal panel 10, is optically rotated to a P wave during the passage through the first liquid crystal panel 10, and exits from the first liquid crystal panel 10. The P wave incident on the second liquid crystal panel 20 is optically rotated to an S wave during the passage through the second liquid crystal panel 20 and spreads once in the Y direction toward the second driving electrode where a transverse electric field is formed. The S wave incident on the third liquid crystal panel 30 spreads once in the Y direction toward the first driving electrode where a transverse electric field is formed. In addition, the S wave is optically rotated to a P wave during the passage through the third liquid crystal panel 30. The P wave incident on the fourth liquid crystal panel 40 does not spread and is optically rotated to an S wave during the passage through the fourth liquid crystal panel 40.

[0173] On the other hand, the P wave incident on the first liquid crystal panel 10 is optically rotated to an S wave during the passage through the first liquid crystal panel 10, spreads once in the Y direction toward the second driving electrode where a transverse electric field is formed, and exits from the first liquid crystal panel 10. The S wave incident on the second liquid crystal panel 20 is optically rotated to a P wave during the passage through the second liquid crystal panel 20 and does not spread during the passage through the second liquid crystal panel 20. The P wave incident on the third liquid crystal panel 30 is optically rotated to an S wave during the passage through the third liquid crystal panel 30 and does not spread during the passage through the third liquid crystal panel 30. The S wave incident on the fourth liquid crystal panel 40 spreads once in the Y direction toward the first driving electrode where a transverse electric field is formed. In addition, the S wave is optically rotated to a P wave during the passage through the fourth liquid crystal panel 40.

[0174] As described above, during the passage from the first liquid crystal panel 10 to the fourth liquid crystal panel 40, the S wave spreads twice in the Y direction, and the P wave also spreads twice in the Y direction. That is, the S wave and the P wave together spread four times in the Y direction. Therefore, as described above, a Figure 21B horizontal light distribution pattern as shown is formed.

[0175] (3) Vertical light distribution pattern

[0176] The vertical light distribution pattern is a linear light distribution pattern that extends relatively long in the vertical direction (the X direction in the present embodiment) (see Figure 23B ). As Figure 23A shown, the low-level voltage VL of the potential A and the potential D is -aV, and the high-level voltage VH is aV. In addition, the potential B and the potential C are 0V. In other words, the potential A and the potential D are pulse voltages with an amplitude of the second amplitude and opposite polarities to each other during the same period. Therefore, pulse voltages are applied to the driving electrode E11 of the first liquid crystal panel 10, the driving electrode E32 of the third liquid crystal panel 30, the driving electrode E21 of the second liquid crystal panel 20, and the driving electrode E42 of the fourth liquid crystal panel 40.

[0177] Specifically, pulse voltages with an amplitude of the second amplitude and opposite polarities during the same period are applied to the driving electrodes E11A and E11B, respectively. Pulse voltages with an amplitude of the second amplitude and opposite polarities during the same period are applied to the driving electrodes E32A and E32B, respectively. Pulse voltages with an amplitude of the second amplitude and opposite polarities during the same period are applied to the driving electrodes E21A and E21B, respectively. Pulse voltages with an amplitude of the second amplitude and opposite polarities during the same period are applied to the driving electrodes E42A and E42B, respectively. Moreover, the operation mode of light diffusion is as Figure 24 shown. On the left side of Figure 24 , shading is added to the driving electrodes that form the electric field.

[0178] As Figure 24 shown, the S wave incident on the first liquid crystal panel 10 does not diffuse during the passage through the first liquid crystal panel 10, is optically rotated to a P wave during the passage through the first liquid crystal panel 10, and exits from the first liquid crystal panel 10. The P wave incident on the second liquid crystal panel 20 is optically rotated to an S wave during the passage through the second liquid crystal panel 20 and diffuses once in the X direction on the side of the first driving electrode that forms the transverse electric field. The S wave incident on the third liquid crystal panel 30 diffuses once in the X direction on the side of the second driving electrode that forms the transverse electric field. In addition, it is optically rotated to a P wave during the passage through the third liquid crystal panel 30. The P wave incident on the fourth liquid crystal panel 40 does not diffuse and is optically rotated to an S wave during the passage through the fourth liquid crystal panel 40.

[0179] On the other hand, the P wave incident on the first liquid crystal panel 10 is optically rotated to an S wave during the passage through the first liquid crystal panel 10, diffuses once in the X direction on the side of the first driving electrode that forms the transverse electric field, and exits from the first liquid crystal panel 1. The S wave incident on the second liquid crystal panel 20 is optically rotated to a P wave during the passage through the second liquid crystal panel 20 and does not diffuse during the passage through the second liquid crystal panel 20. The P wave incident on the third liquid crystal panel 30 is optically rotated to an S wave during the passage through the third liquid crystal panel 30 and does not diffuse during the passage through the third liquid crystal panel 30. The S wave incident on the fourth liquid crystal panel 40 diffuses once in the X direction on the side of the second driving electrode that forms the transverse electric field. In addition, it is optically rotated to a P wave during the passage through the fourth liquid crystal panel 40.

[0180] As described above, during the passage from the first liquid crystal panel 10 to the fourth liquid crystal panel 40, the S wave diffuses twice in the X direction, and the P wave also diffuses twice in the X direction. That is, the S wave and the P wave together diffuse four times in the X direction. Therefore, as described above, a Figure 23B longitudinal line light distribution pattern as shown is formed.

[0181] (4) Elliptical light distribution pattern

[0182] The light distribution pattern of the ellipse is, for example, as Figure 25B shown, a longitudinally elongated elliptical light distribution pattern. As Figure 25A shown, the low-level voltage VL of potential B and potential C is -a'V, and the high-level voltage VH is a'V. In addition, the low-level voltage VL of potential A and potential D is -b'V, and the high-level voltage VH is b'V. a'V is smaller than b'V. -a' is larger than -b'V.

[0183] In other words, potential B and potential C are pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period. That is, the second driving electrodes E12 in the first liquid crystal panel 10, the first driving electrodes E31 in the third liquid crystal panel 30, the driving electrodes E22 in the second liquid crystal panel 20, and the driving electrodes E41 in the fourth liquid crystal panel 40 each have two driving electrodes alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period are applied to the two driving electrodes respectively.

[0184] Specifically, pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period are applied to the driving electrode E12A and the driving electrode E12B respectively. Pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period are applied to the driving electrode E31A and the driving electrode E31B respectively. Pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period are applied to the driving electrode E22A and the driving electrode E22B respectively. Pulse voltages with an amplitude of the third amplitude and opposite polarities to each other during the same period are applied to the driving electrode E41A and the driving electrode E41B respectively.

[0185] In addition, potential A and potential D are pulse voltages with an amplitude of the fourth amplitude different from the third amplitude and opposite polarities to each other during the same period. That is, the driving electrodes E11 in the first liquid crystal panel 10, the driving electrodes E32 in the third liquid crystal panel 30, the driving electrodes E21 in the second liquid crystal panel 20, and the driving electrodes E42 in the fourth liquid crystal panel 40 each have two driving electrodes alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the fourth amplitude and opposite polarities to each other during the same period are applied to the two driving electrodes respectively.

[0186] Specifically, pulse voltages with an amplitude of the fourth amplitude and opposite polarities to each other during the same period are applied to the driving electrode E11A and the driving electrode E11B respectively. Pulse voltages with an amplitude of the fourth amplitude and opposite polarities to each other during the same period are applied to the driving electrode E32A and the driving electrode E32B respectively. Pulse voltages with an amplitude of the fourth amplitude and opposite polarities to each other during the same period are applied to the driving electrode E21A and the driving electrode E21B respectively. Pulse voltages with an amplitude of the fourth amplitude and opposite polarities to each other during the same period are applied to the driving electrode E42A and the driving electrode E42B respectively.

[0187] As described with reference to Figure 17 before being emitted from the fourth liquid crystal panel 40, the S wave incident on the first liquid crystal panel 10 diffuses twice in the X-axis direction and twice in the Y-axis direction. In addition, the P wave incident on the first liquid crystal panel 10 diffuses twice in the X-axis direction and twice in the Y-axis direction during the period from when it is incident on the first liquid crystal panel 10 until it is emitted from the fourth liquid crystal panel 40. That is, it diffuses a total of four times in the X-axis direction and four times in the Y-axis direction. As described above, as Figure 25B shown, an elliptical light distribution pattern is formed.

[0188] (5) Circular light distribution pattern

[0189] As Figure 26A shown, potential A is the same as potential B, and potential C is the same as potential D. In addition, during a certain period, the low-level voltage VL of potentials A and B is -aV and the high-level voltage VH of potentials C and D is aV, and during the next certain period, the high-level voltage VH of potentials A and B is aV and the low-level voltage VL of potentials C and D is -aV. In this case, since in the elliptical alignment pattern described in (4) above, the potential difference between the electrodes extending in the X direction is the same as the potential difference between the electrodes extending in the Y direction, the sizes (diffusion degrees) of the light distribution in the X direction and the Y direction are the same. As a result, a circular light distribution pattern is formed.

[0190] As described above, the lighting device 100 includes: two control substrates 5A and 5B; two relay substrates 4A and 4B, each electrically connected to the two control substrates 5A and 5B via one wire harness 210; and four liquid crystal panels 1A, electrically connected to the two relay substrates 4A and 4B via a flexible printed circuit board 200. Two of the four liquid crystal panels 1A are each electrically connected to the relay substrate 4A (one of the two relay substrates) via one flexible printed circuit board 200. The other two of the four liquid crystal panels 1A are each electrically connected to the relay substrate 4B (the other of the two relay substrates) via one flexible printed circuit board 200.

[0191] Accordingly, a control substrate 5 is connected to a relay substrate 4 via a wiring harness 210, and the relay substrate 4 is connected to two liquid crystal panels 1A via two flexible printed circuit boards 200. That is, the number of wiring harnesses 210 connecting the control substrate 5 and the relay substrate 4 is half the number of flexible printed circuit boards 200 connecting the liquid crystal panel 1A and the relay substrate 4. Therefore, compared with the case where the number of wiring harnesses 210 connecting the control substrate 5 and the relay substrate 4 is the same as the number of flexible printed circuit boards 200 connecting the liquid crystal panel 1A and the relay substrate 4, when the liquid crystal panel 1A and the relay substrate 4 rotate relative to the control substrate 5 and the wiring harness 210 twists, the force applied to the connection portion between the wiring harness 210 and the relay substrate 4 or the connection portion between the wiring harness 210 and the control substrate 5 is smaller. As described above, in the lighting device 100 that rotates the light distribution pattern around the axis (central axis AX), damage to the connection portion between the wiring (flexible printed circuit board 200) and the liquid crystal panel 1A or the connection portion between the wiring (wiring harness 210) and the control substrate 5 can be suppressed.

[0192] Signal lines are provided in the wiring harness 210 and the flexible printed circuit board 200. The signal lines of the wiring harness 210 branch at the relay substrate 4 and are connected to the signal lines of the flexible printed circuit board 200.

[0193] In the case where the signal lines of the wiring harness 210 do not branch at the relay substrate 4, since one control substrate 5 is required for one liquid crystal panel 1A, four control substrates 5 are required for four liquid crystal panels 1A. Therefore, according to the present embodiment, the number of control substrates 5 can be set to be smaller. In addition, by reducing the number of control substrates 5, the number of wiring harnesses 210 is also reduced, and thus the number of connection portions between the wiring harness 210 and the control substrate 5 is also reduced. Therefore, the force applied to the connection portion between the wiring harness 210 and the control substrate 5 is also reduced, and damage to this connection portion can be suppressed.

[0194] The wiring harness 210 is longer than the flexible printed circuit board 200.

[0195] When the liquid crystal panel 1A rotates relative to the control substrate 5, the wiring harness 210 twists. However, since the length of the wiring harness 210 is longer, the force applied to the connection portion between the wiring harness 210 and the relay substrate 4 or the connection portion between the wiring harness 210 and the control substrate 5 is smaller, and damage to this connection portion can be suppressed. In addition, since the length of the flexible printed circuit board 200 can be set shorter, the length of the holding member 2 in the axial direction can be made shorter, and miniaturization of the lighting device 100 can be achieved.

[0196] The lighting device 100 includes: a holding member 2 that holds four liquid crystal panels 1A and two relay substrates 4; and a held member 3 that supports the holding member 2 so as to be rotatable in the axial direction of the central axis AX and on which two control substrates 5A and 5B are mounted.

[0197] Thus, when the light distribution pattern is elongated in one direction (for example, longitudinally or laterally), the light distribution pattern can be rotated about the central axis AX, so that a light distribution pattern with various variations can be provided. For example, as described with reference to Figure 13 As shown, by rotating the light distribution pattern 601 having an elliptical shape that is long along the Y axis counterclockwise by 45 degrees, the light distribution pattern 602 can be obtained.

[0198] The four liquid crystal panels 1A are stacked in order from the Z2 side (one side in the first direction) to the Z1 side (the other side in the first direction) with a first liquid crystal panel 10, a second liquid crystal panel 20, a third liquid crystal panel 30, and a fourth liquid crystal panel 40. When viewed from the Z direction, the orientation of the initial light distribution on the first substrate side of the first liquid crystal panel 10 and the second liquid crystal panel 20 is orthogonal (crossed) to the orientation of the initial light distribution on the first substrate side of the third liquid crystal panel 30 and the fourth liquid crystal panel 40. The relay substrate 4A is electrically connected to the drive electrodes E11, E12, E31, and E32. The relay substrate 4B is electrically connected to the drive electrodes E21, E22, E41, and E42.

[0199] By configuring the lighting device 100 in this way, various light distribution patterns including a light distribution pattern with horizontal lines, a light distribution pattern with vertical lines, an elliptical light distribution pattern, and a circular light distribution pattern can be formed.

[0200] The drive electrodes E12 in the first liquid crystal panel 10, the drive electrodes E31 in the third liquid crystal panel 30, the drive electrodes E22 in the second liquid crystal panel 20, and the drive electrodes E41 in the fourth liquid crystal panel 40 each have two drive electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the first amplitude and opposite polarities in the same period are applied to the two drive electrodes respectively.

[0201] With such a configuration and operation mode, a light distribution pattern with horizontal lines can be formed. In addition, since the holding member 2 is rotatably supported relative to the held member 3, the light distribution pattern with horizontal lines can be rotated.

[0202] The driving electrodes E11 in the first liquid crystal panel 10, the driving electrodes E32 in the third liquid crystal panel 30, the driving electrodes E21 in the second liquid crystal panel 20, and the driving electrodes E42 in the fourth liquid crystal panel 40 each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the second amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

[0203] With such a configuration and operation mode, a longitudinal light distribution pattern can be formed. In addition, since the holding member 2 is rotatably supported with respect to the held member 3, the longitudinal light distribution pattern can be rotated.

[0204] The driving electrodes E12 in the first liquid crystal panel 10 and the driving electrodes E31 in the third liquid crystal panel 30 each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the third amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

[0205] The driving electrodes E21 in the second liquid crystal panel 20 and the driving electrodes E42 in the fourth liquid crystal panel 40 each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the fourth amplitude different from the third amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

[0206] With such a configuration and operation mode, an elliptical light distribution pattern can be formed. In addition, since the holding member 2 is rotatably supported with respect to the held member 3, the elliptical light distribution pattern can be rotated.

[0207] The driving electrodes E11, E21, E31, E41 and the driving electrodes E12, E22, E32, E42 each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the fifth amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

[0208] With such a configuration and operation mode, a circular light distribution pattern can be formed.

[0209] [Second Embodiment]

[0210] Next, the description of the second embodiment will be centered on the content different from that of the first embodiment. Specifically, it is different from the first embodiment in that a cross-shaped light distribution pattern is formed in the second embodiment. The following will be described in detail.

[0211] (Overall Configuration of Lighting Device)

[0212] Figure 27It is a schematic diagram showing the overall configuration of the liquid crystal panel, relay substrate, and control substrate according to the second embodiment. Figure 28 It is a cross-sectional view showing the state of stacking four liquid crystal panels.

[0213] Figure 29A It is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four liquid crystal panels. Figure 29B It is a diagram for overall explanation of the polarization wave, the diffusion direction of the polarization wave, and the potential of the terminals acting in each of the four liquid crystal panels.

[0214] As Figure 27 , Figure 28 , Figure 29A and Figure 29B shown, in the second embodiment, the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30A, and the fourth liquid crystal panel 40A are stacked in order from the side of the LED 110 close to the light source. As Figure 28 shown, a flexible printed circuit board 201A is bonded to the first liquid crystal panel 10, a flexible printed circuit board 202A is bonded to the second liquid crystal panel 20, a flexible printed circuit board 203A is bonded to the third liquid crystal panel 30A, and a flexible printed circuit board 204A is bonded to the fourth liquid crystal panel 40A. The flexible printed circuit boards 201A and 204A extend in the same direction, and the flexible printed circuit boards 202A and 203A extend in the same direction. The flexible printed circuit boards 201A and 204A extend in the opposite direction to the flexible printed circuit boards 202A and 203A.

[0215] As Figure 29A shown, the third liquid crystal panel 30A is arranged to be rotated 90° clockwise with respect to the first liquid crystal panel 10, and the flexible printed circuit board 203A is electrically connected to the second terminal group 20A of the first substrate S31 (see Figure 28 ). The fourth liquid crystal panel 40A is arranged to be rotated 270° clockwise with respect to the first liquid crystal panel 10, and the flexible printed circuit board 204A is electrically connected to the second terminal group 20A of the first substrate S41 (see Figure 28 ).

[0216] In addition, as Figure 27 shown, in the second embodiment, the liquid crystal panel 1A connected to the relay substrates 4A and 4B is different from that in the first embodiment. That is, the first liquid crystal panel 10 and the fourth liquid crystal panel 40A are connected to the relay substrate 4A, and the second liquid crystal panel 20 and the third liquid crystal panel 30A are connected to the relay substrate 4B.

[0217] The fifth terminal 201, the sixth terminal 202, the seventh terminal 203, and the eighth terminal 204 of the fourth liquid crystal panel 40A are connected to the connector 631 of the relay substrate 4A. More specifically, the fifth terminal 201 is connected to the connector 631 via the signal line 705. The sixth terminal 202 is connected to the connector 631 via the signal line 706. The seventh terminal 203 is connected to the connector 631 via the signal line 707. The eighth terminal 204 is connected to the connector 631 via the signal line 708.

[0218] The signal line 701 and the signal line 707 are electrically connected to the signal line 709 via the connectors 631 and 632. That is, two signal lines are connected to one signal line via the connectors 631 and 632. The same applies to other signal lines, where two are connected to one.

[0219] Specifically, the signal line 702 and the signal line 708 are electrically connected to the signal line 710 via the connectors 631 and 632. The signal line 703 and the signal line 705 are electrically connected to the signal line 711 via the connectors 631 and 632. The signal line 704 and the signal line 706 are electrically connected to the signal line 712 via the connectors 631 and 632.

[0220] Moreover, one signal line (for example, the signal line 709) in the relay substrate 4A is electrically connected to one signal line (for example, the signal line 713) in the wire harness 210 via the connector 633.

[0221] Next, the potentials of the signal lines will be described. The signal lines 702, 708, 710, and 714 are at potential A. The signal lines 701, 707, 709, and 713 are at potential B. The signal lines 704, 706, 712, and 716 are at potential C. The signal lines 703, 705, 711, and 715 are at potential D.

[0222] As Figure 27 shown, the fifth terminal 201, the sixth terminal 202, the seventh terminal 203, and the eighth terminal 204 of the third liquid crystal panel 30A are connected to the connector 635 of the relay substrate 4B. More specifically, the fifth terminal 201 is connected to the connector 635 via the signal line 725. The sixth terminal 202 is connected to the connector 635 via the signal line 726. The seventh terminal 203 is connected to the connector 635 via the signal line 727. The eighth terminal 204 is connected to the connector 635 via the signal line 728.

[0223] The signal line 721 and the signal line 727 are electrically connected to the signal line 729 via the connectors 634 and 635. That is, two signal lines are connected to one signal line via the connectors 634 and 635. The same applies to other signal lines, where two are connected to one. Specifically, the signal line 722 and the signal line 728 are electrically connected to the signal line 730 via the connectors 634 and 635. The signal line 723 and the signal line 725 are electrically connected to the signal line 731 via the connectors 634 and 635. The signal line 724 and the signal line 726 are electrically connected to the signal line 732 via the connectors 634 and 635.

[0224] Moreover, one signal line in the relay substrate 4B is electrically connected to one signal line in the control substrate 5B via the connector 636.

[0225] Next, the potentials of the signal lines will be described. The signal line 722, the signal line 728, the signal line 730, and the signal line 734 have the potential A'. The signal line 721, the signal line 727, the signal line 729, and the signal line 733 have the potential B'. The signal line 724, the signal line 726, the signal line 732, and the signal line 736 have the potential C'. The signal line 723, the signal line 725, the signal line 731, and the signal line 735 have the potential D'.

[0226] (Light distribution pattern)

[0227] Next, the light distribution pattern will be described. Figure 30A It is a diagram showing the waveform of the control signal applied to the electrodes for driving the liquid crystal in the light distribution pattern of cross light distribution. Figure 30B It is an image showing the light distribution pattern of cross light distribution. Figure 31 It is a diagram schematically illustrating the state of forming the light distribution pattern of cross light distribution using four liquid crystal panels.

[0228] (1) Cross-shaped light distribution pattern

[0229] The cross-shaped light distribution pattern is, for example, as Figure 30B shown, a cross-shaped light distribution pattern where the vertical and horizontal directions are orthogonal (cross).

[0230] As Figure 30A shown, the potential B and the potential C alternate between the low-level voltage VL and the high-level voltage VH. The voltage VL is, for example, -a'V, and the voltage VH is, for example, a'V. The potential A' and the potential D' alternate between the low-level voltage VL and the high-level voltage VH. The voltage VL is, for example, -b'V, and the voltage VH is, for example, b'V. As Figure 30A shown, all potentials other than the potential B, the potential C, the potential A', and the potential D' are 0V. Therefore, referring to Figure 27, a potential B and a potential C are applied to the driving electrode E12 of the second substrate S12 in the first liquid crystal panel 10. A potential A' and a potential D' are applied to the driving electrode E21 of the first substrate S21 in the second liquid crystal panel 20. A potential A' and a potential D' are applied to the driving electrode E32 of the second substrate S32 in the third liquid crystal panel 30A. A potential B and a potential C are applied to the driving electrode E41 of the first substrate S41 in the fourth liquid crystal panel 40A.

[0231] In other words, the driving electrode E12 in the first liquid crystal panel 10 and the driving electrode E41 in the fourth liquid crystal panel 40A each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the eleventh amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively. The driving electrode E21 in the second liquid crystal panel 20 and the driving electrode E32 in the third liquid crystal panel 30A each have two driving electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an amplitude of the twelfth amplitude different from the eleventh amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

[0232] In summary, it becomes Figure 31 the form shown. In Figure 31 , shading is also added to the driving electrodes to which voltages are applied.

[0233] As Figure 31 shown, the S wave incident on the first liquid crystal panel 10 diffuses twice in the X direction during the process from the first liquid crystal panel 10 to the fourth liquid crystal panel 40A. The P wave incident on the first liquid crystal panel 10 diffuses twice in the Y direction during the process from the first liquid crystal panel 10 to the fourth liquid crystal panel 40A. Hereinafter, a detailed description will be given.

[0234] As Figure 31 shown, the S wave incident on the first liquid crystal panel 10 undergoes optical rotation without diffusion and is emitted from the first liquid crystal panel 10 as a P wave. The P wave incident on the second liquid crystal panel 20 diffuses once in the X direction on the side of the first substrate S21. Then, it undergoes optical rotation and is emitted from the second liquid crystal panel 20 as an S wave. The S wave incident on the third liquid crystal panel 30A diffuses once in the X direction on the side of the second substrate S32, and in addition, undergoes optical rotation and is emitted from the third liquid crystal panel 30A as a P wave. The P wave incident on the fourth liquid crystal panel 40A undergoes optical rotation without diffusion and is emitted from the fourth liquid crystal panel 40A as a P wave.

[0235] In addition, the P wave incident on the first liquid crystal panel 10 diffuses once in the Y direction on the second substrate S12 side. In addition, optical rotation occurs and the wave exits the first liquid crystal panel 10 as an S wave. The S wave incident on the second liquid crystal panel 20 does not diffuse but undergoes optical rotation and exits the second liquid crystal panel 20 as a P wave. The P wave incident on the third liquid crystal panel 30A does not diffuse but undergoes optical rotation and exits the third liquid crystal panel 30A as an S wave. The S wave incident on the fourth liquid crystal panel 40A diffuses once in the Y direction on the first substrate S31 side. In addition, optical rotation occurs and the wave exits the fourth liquid crystal panel 40A as a P wave. It should be noted that since b'V is greater than a'V and -b'V is less than -a'V, Figure 31 the degree of diffusion in the second liquid crystal panel 20 and the third liquid crystal panel 30A shown in Figure 31 is greater than that in the first liquid crystal panel 10 and the fourth liquid crystal panel 40A. Since the diffusion in the second liquid crystal panel 20 and the third liquid crystal panel 30A is in the X direction, in cross illumination, the length in the X direction is longer than the length in the Y direction.

[0236] As described above, the four liquid crystal panels 1A are stacked in order from the Z2 side to the Z1 side with the first liquid crystal panel 10, the second liquid crystal panel 20, the third liquid crystal panel 30A, and the fourth liquid crystal panel 40A. When viewed from the Z direction, the orientation of the initial illumination on the first substrate side in the first liquid crystal panel 10 and the second liquid crystal panel 20 is orthogonal (crossed) to the orientation of the initial illumination on the first substrate side in the third liquid crystal panel 30 and the fourth liquid crystal panel 40A. The relay substrate 4A is electrically connected to the first drive electrode E11, the second drive electrode E12, the first drive electrode E41, and the second drive electrode E42. The relay substrate 4B is electrically connected to the first substrate side drive electrode E21, the second drive electrode E22, the first drive electrode E31, and the second drive electrode E32. Moreover, by applying potentials B and C to the drive electrodes E12 and E41 and applying A' and D' to the drive electrodes E21 and E32, a cross-shaped illumination pattern can be formed.

[0237] [Modification of the Second Embodiment]

[0238] In the second embodiment, by setting Figure 27 the potentials A', B', C', and D' shown to the potentials A, B, C, and D respectively (that is, setting A' = A, B' = B, C' = C, D' = D), the same potential state as in the first embodiment can be achieved. Hereinafter, the illumination pattern related to the modification of the second embodiment will be briefly described. It should be noted that in this modification, the potential state and the illumination state are basically the same as in the first embodiment.

[0239] (1) Narrow light distribution pattern

[0240] As described above, potential A is the same as potential A', potential B is the same as potential B', potential C is the same as potential C', and potential D is the same as potential D'. Therefore, the narrow light distribution pattern involved in this modification is the same as that of the first embodiment.

[0241] (2) Horizontal line light distribution pattern

[0242] The driving electrodes E12 in the first liquid crystal panel 10, the driving electrodes E41 in the fourth liquid crystal panel 40A, the driving electrodes E22 in the second liquid crystal panel 20, and the driving electrodes E31 in the third liquid crystal panel 30A each have two driving electrodes that are alternately arranged when viewed from the Z direction. Pulse voltages with an amplitude of the sixth amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively. Therefore, a horizontally long extending horizontal line-shaped light distribution pattern is formed in the same operation mode as the first embodiment.

[0243] (3) Vertical line light distribution pattern

[0244] The driving electrodes E11 in the first liquid crystal panel 10, the driving electrodes E42 in the fourth liquid crystal panel 40A, the driving electrodes E21 in the second liquid crystal panel 20, and the driving electrodes E32 in the third liquid crystal panel 30A each have two driving electrodes that are alternately arranged when viewed from the Z direction. Pulse voltages with an amplitude of the seventh amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively. Therefore, a vertically long extending vertical line-shaped light distribution pattern is formed in the same operation mode as the first embodiment.

[0245] (4) Elliptical light distribution pattern

[0246] The elliptical light distribution pattern is an elliptical light distribution pattern that is the same as that of the first embodiment.

[0247] Here, potential A is the same as potential A', potential B is the same as potential B', potential C is the same as potential C', and potential D is the same as potential D'. Therefore, it is the same as Fig. 35A related to the first embodiment.

[0248] The drive electrodes E12 in the first liquid crystal panel 10 and the drive electrodes E41 in the fourth liquid crystal panel 40A each have two drive electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with an eighth amplitude and opposite polarities during the same period are applied to the two drive electrodes respectively. In addition, the drive electrodes E21 in the second liquid crystal panel 20 and the drive electrodes E32 in the third liquid crystal panel 30A each have two drive electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with a ninth amplitude different from the eighth amplitude and opposite polarities during the same period are applied to the two drive electrodes respectively. Therefore, an elliptical light distribution pattern is formed in the same operation mode as in the first embodiment.

[0249] (5) Circular light distribution pattern

[0250] The drive electrodes E11 in the first liquid crystal panel 10, the drive electrodes E12 in the first liquid crystal panel 10, the drive electrodes E41 in the fourth liquid crystal panel 40A, the drive electrodes E42 in the fourth liquid crystal panel 40A, the drive electrodes E21 in the second liquid crystal panel 20, the drive electrodes E22 in the second liquid crystal panel 20, the drive electrodes E31 in the third liquid crystal panel 30A, and the drive electrodes E32 in the third liquid crystal panel 30A each have two drive electrodes that are alternately arranged when viewed from the Z direction, and pulse voltages with a tenth amplitude and opposite polarities during the same period are applied to the two drive electrodes respectively. Therefore, a circular light distribution pattern is formed in the same operation mode as in the first embodiment.

[0251] Explanation of reference numerals

[0252] 1 Optical element; 1A Liquid crystal panel; 2 Holding member; 3 Held member; 4 Relay substrate; 4A, 4B Relay substrates; 5 Control substrate; 5A, 5B Control substrates; 10 First liquid crystal panel; 20

[0253] Second liquid crystal panel; 30, 30A Third liquid crystal panels; 40, 40A Fourth liquid crystal panels; 60 Liquid crystal layer; 100 Lighting device; 200 Flexible printed circuit board; 210 Wiring harness; E11, E11A, E11B, E21, E21A, E21B, E31, E31A, E31B, E41, E41A, E41B First drive electrodes (drive electrodes); E12, E12A, E12B, E22, E22A, E22B, E32, E32A, E32B, E42, E42A, E42B Second drive electrodes (drive electrodes).

Claims

1. A lighting device, comprising: Two control substrates; Two relay substrates, each electrically connected to one of the two control substrates via a wiring harness; and Four liquid crystal panels, electrically connected to the two relay substrates via flexible printed circuit boards, Four of the flexible printed circuit boards are provided, Two of the four liquid crystal panels are each electrically connected to one of the two relay substrates via one of the flexible printed circuit boards, The other two of the four liquid crystal panels are each electrically connected to the other of the two relay substrates via one of the flexible printed circuit boards, The four liquid crystal panels are arranged in a stacked state in a first direction.

2. The lighting device according to claim 1, wherein Signal lines are provided in the wiring harness and the flexible printed circuit board, The signal lines of the wiring harness branch at the relay substrate and are connected to the signal lines of the flexible printed circuit board.

3. The lighting device according to claim 1, wherein The wiring harness is longer than the flexible printed circuit board.

4. The lighting device according to any one of claims 1 to 3, wherein The lighting device comprises: A holding member having a central axis extending in a first direction and holding the four liquid crystal panels and the two relay substrates; And A held member that supports the holding member so as to be rotatable in the axial direction of the central axis, and the held member is mounted with a light source and the two control substrates.

5. The lighting device according to claim 4, wherein The four liquid crystal panels are stacked in order from one side to the other side in the first direction with a first liquid crystal panel, a second liquid crystal panel, a third liquid crystal panel, and a fourth liquid crystal panel, The first liquid crystal panel and the second liquid crystal panel each have: A first substrate on one side in the first direction, a second substrate on the other side in the first direction, a liquid crystal layer provided between the first substrate and the second substrate, a first driving electrode provided on the first substrate, and a second driving electrode provided on the second substrate and extending in a direction crossing the first driving electrode when viewed from the first direction. The initial light distribution direction on the first substrate side crosses the initial light distribution direction on the second substrate side when viewed from the first direction. The third liquid crystal panel and the fourth liquid crystal panel each have: A first substrate on one side in the first direction, a second substrate on the other side in the first direction, a liquid crystal layer provided between the first substrate and the second substrate, a first driving electrode provided on the first substrate, and a second driving electrode provided on the second substrate and extending in a direction crossing the first driving electrode when viewed from the first direction. The initial light distribution direction on the first substrate side crosses the initial light distribution direction on the second substrate side when viewed from the first direction. When observed from the first direction, the orientation of the initial light distribution on the first substrate side of the first liquid crystal panel and the second liquid crystal panel intersects with the orientation of the initial light distribution on the first substrate side of the third liquid crystal panel and the fourth liquid crystal panel. One of the two relay substrates is electrically connected to the first driving electrode and the second driving electrode in the first liquid crystal panel and the first driving electrode and the second driving electrode in the third liquid crystal panel. The other of the two relay substrates is electrically connected to the first driving electrode and the second driving electrode in the second liquid crystal panel and the first driving electrode and the second driving electrode in the fourth liquid crystal panel.

6. The lighting device according to claim 4, wherein The four liquid crystal panels are stacked in sequence from one side to the other side in the first direction, with the first liquid crystal panel, the second liquid crystal panel, the third liquid crystal panel, and the fourth liquid crystal panel. The first liquid crystal panel and the second liquid crystal panel each have: A first substrate on one side in the first direction, a second substrate on the other side in the first direction, a liquid crystal layer disposed between the first substrate and the second substrate, a first driving electrode disposed on the first substrate, and a second driving electrode disposed on the second substrate and extending in a direction intersecting the first driving electrode when observed from the first direction. The orientation of the initial light distribution on the first substrate side intersects with the orientation of the initial light distribution on the second substrate side when observed from the first direction. The third liquid crystal panel and the fourth liquid crystal panel each have: A first substrate on one side in the first direction, a second substrate on the other side in the first direction, a liquid crystal layer disposed between the first substrate and the second substrate, a first driving electrode disposed on the first substrate, and a second driving electrode disposed on the second substrate and extending in a direction intersecting the first driving electrode when observed from the first direction. The orientation of the initial light distribution on the first substrate side intersects with the orientation of the initial light distribution on the second substrate side when observed from the first direction. When observed from the first direction, the orientation of the initial light distribution on the first substrate side of the first liquid crystal panel and the second liquid crystal panel intersects with the orientation of the initial light distribution on the first substrate side of the third liquid crystal panel and the fourth liquid crystal panel. One of the two relay substrates is electrically connected to the first driving electrode and the second driving electrode in the first liquid crystal panel and the first driving electrode and the second driving electrode in the fourth liquid crystal panel. The other of the two relay substrates is electrically connected to the first driving electrode and the second driving electrode in the second liquid crystal panel and the first driving electrode and the second driving electrode in the third liquid crystal panel.

7. The lighting device according to claim 6, wherein The second driving electrode in the first liquid crystal panel and the first driving electrode in the fourth liquid crystal panel each have two driving electrodes that are alternately arranged when viewed from the first direction, and pulse voltages with an amplitude of the eleventh amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively. The first driving electrode in the second liquid crystal panel and the second driving electrode in the third liquid crystal panel each have two driving electrodes that are alternately arranged when viewed from the first direction, and pulse voltages with an amplitude of the twelfth amplitude different from the eleventh amplitude and opposite polarities during the same period are applied to the two driving electrodes respectively.

Images