Light control device

Abstract

This light control device is provided with a light source and a panel unit in which a plurality of light control panels are layered in the Z direction. At least one of the plurality of light control panels in the panel unit includes: a first substrate that is provided with an electrode; a second substrate that overlaps the first substrate in a first direction and is provided with an electrode; and a liquid crystal layer that is applied between the first substrate and the second substrate. With respect to a voltage applied to the electrode provided to the first substrate and a voltage applied to the electrode provided to the second substrate, the frequencies and / or the phases are different.

Description

dimmer

[0001] The present disclosure relates to a light control device.

[0002] The light control device described in Patent Document 1 includes a light source and a panel unit. The panel unit has multiple light control panels stacked vertically. When incident light enters the light source side of the panel unit, the panel unit adjusts the light transmittance of the incident light, and the adjusted transmitted light exits from the light control panel on the opposite side from the light source.

[0003] Each of the plurality of light control panels includes a lower substrate, a drive electrode on the lower substrate, an upper substrate, a drive electrode on the upper substrate, and a liquid crystal layer. When a voltage is applied to the drive electrode on the lower substrate, an electric field having a convex arc shape is generated upward, and when a voltage is applied to the drive electrode on the upper substrate, an electric field having a convex arc shape is generated downward.

[0004] JP 2010-230887 A

[0005] When the voltage applied to the upper and lower drive electrodes is increased, the arc-shaped electric field located at the upper side and the arc-shaped electric field located at the lower side each become stronger, causing the upper electric field and the lower electric field to intersect at the middle part of the liquid crystal layer in the thickness direction. This causes the alignment of the liquid crystal molecules located in the middle part of the liquid crystal layer in the thickness direction to become disordered, resulting in unintended diffusion and possibly reducing the illuminance of the light emitted from the panel unit of the light control device.

[0006] An object of the present disclosure is to provide a light control device that can suppress a decrease in the illuminance of emitted light.

[0007] A dimming device according to one embodiment of the present disclosure comprises a light source and a panel unit in which a plurality of dimming panels are stacked in a first direction, wherein at least one of the plurality of dimming panels in the panel unit has a first substrate on which an electrode is provided, a second substrate overlapping the first substrate in the first direction and on which an electrode is provided, and a liquid crystal layer filled between the first substrate and the second substrate, and at least one of the frequency and phase of the voltage applied to the electrode on the first substrate and the voltage applied to the electrode on the second substrate is different.

[0008] FIG. 1 is a schematic diagram of a dimming panel according to the first embodiment, viewed from above. FIG. 2 is a plan view of a first substrate according to the first embodiment. FIG. 3 is a plan view of a second substrate according to the first embodiment. FIG. 4 is a plan view of a dimming panel in which a second substrate is superimposed on a first substrate. FIG. 5 is a schematic diagram of four dimming panels constituting a dimming device according to the first embodiment. FIG. 6 is a schematic diagram showing a cross section of a panel unit according to the first embodiment. FIG. 7 is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four dimming panels. FIG. 8 is a schematic perspective view of a dimming panel, showing the arrangement of drive electrodes. FIG. 9A is a cross-sectional view of a dimming panel, showing the alignment state of liquid crystal molecules when no voltage is applied to the drive electrodes on the first substrate. FIG. 9B is a cross-sectional view of a dimming panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the drive electrodes on the first substrate. FIG. 9C is a cross-sectional view of a dimming panel, showing the alignment state of liquid crystal molecules when a voltage is applied to the drive electrodes on the second substrate side. FIG. 10 is a view of the dimming panel from above, showing the direction of the electric field at the center of the liquid crystal layer in the thickness direction with an arrow. FIG. 11 is a block diagram of a dimming device. FIG. 12A is a diagram showing the waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the first embodiment. FIG. 12B is a diagram showing the direction of the electric field at the center of the liquid crystal layer in the thickness direction with an arrow from the first period to the fourth period of FIG. 12A. FIG. 13A is a diagram showing the waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in a comparative example. FIG. 13B is a diagram showing the direction of the electric field at the center of the liquid crystal layer in the thickness direction with an arrow from the first period to the second period of FIG. 13A. FIG. 14A is a schematic diagram showing the movement of liquid crystal molecules when the electric field of FIG. 12B is applied. Fig. 14B is a schematic diagram showing the movement of liquid crystal molecules when the electric field of Fig. 13B is applied. Fig. 15 is a graph showing changes in illuminance in an example and a comparative example. Fig. 16A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 1. Fig. 16B is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 2.16C is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 3. FIG. 16D is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 4. FIG. 17A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the second embodiment. FIG. 17B is a diagram showing the direction of the electric field at the center of the thickness direction of the liquid crystal layer with arrows in the first to fourth periods of FIG. 17A. FIG. 18A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the third embodiment. FIG. 18B is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 5. FIG. 19A is a schematic diagram of a first aspect showing wiring connecting four dimming panels. Fig. 19B is a schematic diagram showing the correspondence between the first and second substrates of the four dimming panels shown in Fig. 7 and Fig. 19A. Fig. 20A is a schematic diagram of a second mode showing wiring connecting the four dimming panels. Fig. 20B is a schematic diagram showing the correspondence between the first and second substrates of the four dimming panels shown in Fig. 7 and Fig. 20A.

[0009] Modes (embodiments) for carrying out the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate.

[0010] It should be noted that the disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive of while maintaining the gist of the disclosure are naturally included within the scope of the present disclosure. Furthermore, in order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, in this specification and each drawing, elements similar to those described above with respect to the previous drawings may be assigned the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] In the XYZ coordinate system shown in the figure, the X direction is the left-right direction, and the X1 side is opposite the X2 side. The X1 side is also referred to as the left side, and the X2 side is also referred to as the right side. The Y direction is the front-to-back direction, and the Y1 side is opposite the Y2 side. The Y1 side is also referred to as the front side, and the Y2 side is also referred to as the rear side. The Z direction is the up-down direction (stacking direction). The Z1 side is opposite the Z2 side. The Z1 side is also referred to as the upper side, and the Z2 side is also referred to as the lower side. The Z direction is also referred to as the first direction.

[0012] First Embodiment First, a description will be given of a light control panel 1 according to a first embodiment. Fig. 1 is a schematic diagram of a light control panel according to the first embodiment as viewed from above.

[0013] 1 , the dimming panel 1 includes a first substrate 2 and a second substrate 3 disposed on the upper side (Z1 side) of the first substrate 2. The dimming panel 1 is octagonal 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. Note that, in the present invention, the shape of the dimming panel 1 is not particularly limited, and polygons other than an octagon, as well as circles and ellipses, are also included in the present invention.

[0014] An end 2c on the Y1 side of the first substrate 2 is exposed at the first side 11. A first terminal group 10 is provided at the end 2c.

[0015] An end 2d on the X1 side of the first substrate 2 is exposed at the second side 12. A second terminal group 20 is provided at the end 2d. The active area AA has a circular shape in a plan view.

[0016] Next, the wiring of the first substrate 2 and the second substrate 3 will be described. Fig. 2 is a plan view of the first substrate according to the first embodiment. Fig. 3 is a plan view of the second substrate according to the first embodiment. Fig. 4 is a plan view of a light control panel in which the second substrate is superimposed on the first substrate.

[0017] 2, wiring, drive electrodes, and connection portions are provided on the first substrate 2. Note that connection portion C1 of the first substrate 2 and connection portion C3 (see FIG. 3) of the second substrate 3 are electrically connected via a conductive member (not shown). Similarly, connection portion C2 of the first substrate 2 and connection portion C4 (see FIG. 3) of the second substrate 3 are electrically connected via a conductive member (not shown).

[0018] The first substrate 2 is octagonal in plan view, and has a first side 211, a second side 212, a third side 213, a fourth side 214, a fifth side 215, a sixth side 216, a seventh side 217, and an eighth side 218.

[0019] The first terminal group 10 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 side by side in the X direction from the X1 side to the X2 side.

[0020] The second terminal group 20 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 side by side in the Y direction from the Y1 side to the Y2 side.

[0021] The first terminal 101 and the fifth terminal 201 are electrically connected via a wiring 241. A connection portion C1 is provided midway along the wiring 241.

[0022] The second terminal 102 and the sixth terminal 202 are electrically connected via wires 243 and 245. A branch point 244 is provided in the wire 243, and a wire 246 extends from the branch point 244 to an end 247.

[0023] The third terminal 103 and the seventh terminal 203 are electrically connected via a wiring 248. The fourth terminal 104 and the eighth terminal 204 are electrically connected via wirings 249 and 251. A connection portion C2 is provided between the wiring 249 and the wiring 251.

[0024] The plurality of drive electrodes (first drive electrodes) 261 are connected to the wiring 243 and 246. The plurality of drive electrodes (second drive electrodes) 262 are connected to the wiring 248. The drive electrode 261 is also referred to as the first drive electrode. The drive electrode 262 is also referred to as the second drive electrode. Both the drive electrodes 261 and 262 extend in the X direction. Specifically, the drive electrodes 261 and 262 are bent in a V-shape that protrudes toward the Y2 side. The drive electrodes 261 and 262 are arranged alternately in the Y direction. In this way, the electrodes provided on the first substrate 2 include the drive electrode 261 and the drive electrode 262 arranged adjacent to the drive electrode 261.

[0025] 3 , wiring, drive electrodes, and connection portions are provided on the second substrate 3. The second substrate 3 is octagonal in plan view, and has a first side 311, a second side 312, a third side 313, a fourth side 314, a fifth side 315, a sixth side 316, a seventh side 317, and an eighth side 318.

[0026] The connection portion C3 is connected to the wiring 343. The connection portion C4 is connected to the wiring 346. The wiring 343 extends along the first side 311, the third side 313, and the eighth side 318. The wiring 346 extends along the fourth side 314, the fifth side 315, and the sixth side 316.

[0027] A plurality of drive electrodes (third drive electrodes) 361 are connected to wiring 343. A plurality of drive electrodes (fourth drive electrodes) 362 are connected to wiring 346. The drive electrode 361 is also referred to as a third drive electrode. The drive electrode 362 is also referred to as a fourth drive electrode. Both the drive electrodes 361 and 362 extend in the Y direction. Specifically, the drive electrodes 361 and 362 are bent in a V-shape convex toward the X2 side. The drive electrodes 361 and 362 are arranged alternately in the X direction. In this way, the electrodes provided on the second substrate 3 include the drive electrode 361 and the drive electrode 362 arranged adjacent to the drive electrode 361.

[0028] As shown in Fig. 4 , in the light-modulating panel 1 in which the second substrate 3 of Fig. 3 is superimposed on the first substrate 2 of Fig. 2 , ends 2c and 2d of the first substrate 2 are exposed. When the second substrate 3 is superimposed on the first substrate 2, the first side 311, the third side 313, and the second side 312 of the second substrate 3 are located inside (at the center in a plan view) the first side 211, the third side 213, and the second side 212 of the first substrate 2. As such, since the area of ​​the second substrate 3 is smaller than the area of ​​the first substrate 2, in Fig. 4 , the first terminal group 10 provided at end 2c of the first substrate 2 and the second terminal group 20 provided at end 2d are exposed. The drive electrodes 361 and 362 are arranged to intersect with the drive electrodes 261 and 262.

[0029] Next, a brief description will be given of the configuration of the dimming device 100 according to the first embodiment. Fig. 5 is a schematic diagram of four dimming panels constituting the dimming device according to the first embodiment. Fig. 6 is a schematic diagram showing a cross section of a panel unit according to the first embodiment. Fig. 7 is a schematic diagram showing the arrangement of the first substrate and the second substrate in each of the four dimming panels.

[0030] 5 and 6 , the dimming device 100 includes a light source 630 and a panel unit 110. The light source 630 is located on the upper side (Z1 side) of the panel unit 110. In the panel unit 110, a first dimming panel 1A, a second dimming panel 1B, a third dimming panel 1C, and a fourth dimming panel 1D are stacked in this order from the top. Note that the number of dimming panels 1 included in the dimming device 100 is not limited to four, and may be two or more.

[0031] As shown in Fig. 5, in the first dimming panel 1A, the first terminal group 10 (see Fig. 4) provided on the end portion 2c of the first substrate 2 is located on the Y1 side, and the flexible printed circuit board 41 can be electrically connected to the first terminal group 10. In the second dimming panel 1B, the first dimming panel 1A is rotated 180 degrees clockwise in a plan view. Therefore, the first terminal group 10 is located on the Y2 side, and the flexible printed circuit board 41 can be electrically connected to the first terminal group 10.

[0032] The third dimming panel 1C is obtained by rotating the first dimming panel 1A by 270 degrees clockwise in a plan view, so that the second terminal group 20 provided at the end 2d is located on the Y1 side, and the flexible printed circuit board 41 is electrically connectable to the second terminal group 20. The fourth dimming panel 1D is obtained by rotating the first dimming panel 1A by 90 degrees clockwise in a plan view, so that the second terminal group 20 provided at the end 2d is located on the Y2 side, and the flexible printed circuit board 41 is electrically connectable to the second terminal group 20.

[0033] 6 and 7, in detail, the first dimming panel 1A includes a first substrate S41 (first substrate 2) and a second substrate S42 (second substrate 3) stacked on the upper side (Z1 side) of the first substrate S41. The second dimming panel 1B includes a first substrate S31 (first substrate 2) and a second substrate S32 (second substrate 3) stacked on the upper side (Z1 side) of the first substrate S31. The third dimming panel 1C includes a first substrate S21 (first substrate 2) and a second substrate S22 (second substrate 3) stacked on the upper side (Z1 side) of the first substrate S21. The fourth dimming panel 1D includes a first substrate S11 (first substrate 2) and a second substrate S12 (second substrate 3) stacked on the upper side (Z1 side) of the first substrate S11.

[0034] 7, the drive electrodes 261 and 262 provided on the first substrate S41 in the first dimming panel 1A extend in the X direction as indicated by the white arrows. The drive electrodes 361 and 362 provided on the second substrate S42 extend in the Y direction as indicated by the white arrows.

[0035] The drive electrodes 261 and 262 provided on the first substrate S31 extend in the X direction as indicated by the white arrows. The drive electrodes 361 and 362 provided on the second substrate S32 extend in the Y direction as indicated by the white arrows.

[0036] The drive electrodes 261 and 262 provided on the first substrate S21 extend in the Y direction as indicated by the open arrows. The drive electrodes 361 and 362 provided on the second substrate S22 extend in the X direction as indicated by the open arrows. The drive electrodes 261 and 262 provided on the first substrate S11 extend in the Y direction as indicated by the open arrows. The drive electrodes 361 and 362 provided on the second substrate S12 extend in the X direction as indicated by the open arrows.

[0037] Next, a general operating mode for diffusing light will be described. Fig. 8 is a schematic perspective view of a dimming panel, showing the arrangement of drive electrodes. As shown in Fig. 8, the dimming panel 1 includes a first substrate 2, drive electrodes 261 and 262 provided on the first substrate 2, a second substrate 3, drive electrodes 361 and 362 provided on the second substrate 3, a liquid crystal layer LC disposed between the first substrate 2 and the second substrate 3, a first alignment film AL11, and a second alignment film AL12.

[0038] As shown in FIG. 8, the drive electrodes 261 and 262 and the drive electrodes 361 and 362 are a pair of electrodes arranged with the liquid crystal layer LC sandwiched therebetween.

[0039] 9A is a cross-sectional view of the dimming panel, showing the alignment state of the liquid crystal molecules when no voltage is applied to the drive electrodes on the first substrate side. 9B is a cross-sectional view of the dimming panel, showing the alignment state of the liquid crystal molecules when a voltage is applied to the drive electrodes on the first substrate side. 9C is a cross-sectional view of the dimming panel, showing the alignment state of the liquid crystal molecules when a voltage is applied to the drive electrodes on the second substrate side. Note that FIGS. 9A and 9B are views of the dimming panel viewed from the direction of arrow 610 in FIG. 8, and FIG. 9C is a view of the dimming panel viewed from the direction of arrow 620 in FIG. 8.

[0040] As shown in Fig. 9A, a first alignment film AL11 is formed on the drive electrodes 261 and 262, and as shown in Fig. 9C, a second alignment film AL12 is formed on the drive electrodes 361 and 362. A liquid crystal layer LC is filled between the first substrate 2 and the second substrate 3. As shown in Fig. 9B, the central portion of the liquid crystal layer LC in the Z direction is an intermediate layer LC1. The liquid crystal layer LC includes a plurality of liquid crystal molecules 60. Of the liquid crystal molecules 60, the liquid crystal molecules 60 arranged in the intermediate layer LC1 are referred to as liquid crystal molecules 60A.

[0041] 9A shows that the alignment direction of the first alignment film AL11 and the alignment direction of the second alignment film AL12 are different in the light-controlling panel 1. Specifically, the first alignment film AL11 is aligned in the Y direction, and the second alignment film AL12 is aligned in the X direction. Thus, the alignment directions of the first alignment film AL11 and the second alignment film AL12 are substantially perpendicular to each other when viewed from the Z direction. As a result, the initial light distribution direction on the first substrate 2 side is perpendicular to (intersects with) the initial light distribution direction on the second substrate 3 side when viewed from the Z direction. The alignment process may be a rubbing process or a photo-alignment process. The alignment direction of the alignment film can be set within a range of 90 degrees ±10 degrees relative to the extension direction of the drive electrodes.

[0042] Because the alignment direction of the first alignment film AL11 and the alignment direction of the second alignment film AL12 are approximately perpendicular to each other, the liquid crystal molecules 60 of the liquid crystal layer LC are aligned such that the long axis directions of the liquid crystal molecules 60 are twisted by 90 degrees from the first alignment film AL11 to the second alignment film AL12 when not subjected to the action of an external electric field. 9A shows a state in which no voltage is applied to the drive electrodes 261 and 262, and therefore, as shown in FIG. 9A , the long axis directions of the liquid crystal molecules 60 are aligned such that they are twisted by 90 degrees from the first alignment film AL11 to the second alignment film AL12.

[0043] More specifically, the initial alignment direction (the direction of the long axis of the liquid crystal molecules) of the liquid crystal molecules 60 in the liquid crystal layer LC gradually rotates from the first substrate 2 side toward the second substrate 3 side, and finally rotates by 90 degrees. When an electric field is generated between the adjacent electrodes of each substrate, the liquid crystal molecules that were aligned in the initial alignment direction rotate their orientation from the initial alignment direction in accordance with the direction of the electric field, which causes a refractive index distribution of light to occur in the liquid crystal layer LC.

[0044] 9A shows an example in which, for example, a positive twisted nematic liquid crystal (TN liquid crystal) is used as the liquid crystal layer LC, and the long axes of the liquid crystal molecules 60 are aligned in the same direction as the alignment direction of the alignment film. The liquid crystal layer LC preferably contains a chiral agent that imparts a twist to the liquid crystal molecules 60.

[0045] 12A , for example, when a voltage in which a low-level voltage VL and a high-level voltage VH alternate periodically is applied to the drive electrodes 261 and 262, a transverse electric field is generated between the drive electrodes 261 and 262 as shown in Fig. 9B . As shown in Fig. 9B , the liquid crystal molecules 60 on the first substrate 2 side are affected by the transverse electric field and their orientation direction changes. For example, the orientation of the liquid crystal molecules 60 on the first substrate 2 side changes so that their major axes are oriented parallel to the direction of the electric field.

[0046] It is known that the refractive index of liquid crystal changes depending on its orientation. As shown in FIG. 9A , in the OFF state where no electric field is applied to the liquid crystal layer LC, the long axis direction of the liquid crystal molecules 60 is aligned horizontally to the substrate surface, and is twisted 90 degrees from the first substrate 2 side to the second substrate 3 side. The liquid crystal layer LC has a nearly uniform refractive index distribution in this orientation state. Therefore, the S-wave and P-wave perpendicular to the S-wave of light incident on the light control panel 1 are rotated due to the initial orientation of the liquid crystal molecules 60, but are transmitted through the liquid crystal layer LC in the Z direction with almost no refraction (or scattering). Note that optical rotation refers to the change in the polarization direction of polarized light components as they pass through the liquid crystal layer LC. Specifically, this refers to the change of P-polarized light components (P-wave) to S-polarized light components (S-wave) and vice versa as they pass through the liquid crystal layer LC.

[0047] 9B , in the ON state where a voltage is applied to the drive electrodes 261 and 262 to form an electric field, if the liquid crystal layer LC has positive dielectric anisotropy, the liquid crystal molecules 60 are oriented with their major axes aligned along the electric field. As a result, as shown in FIG. 9B , the liquid crystal layer LC is formed with regions where the liquid crystal molecules 60 stand almost vertically above the drive electrodes 261 and 262, regions where they are oriented obliquely in accordance with the distribution of the electric field between the drive electrodes 261 and 262, and regions away from the drive electrodes 261 and 262 where the initial alignment state is maintained.

[0048] As shown in FIG. 9B , between the drive electrodes 261 and 262, the long axes of the liquid crystal molecules 60 are aligned in a convex arc shape along the direction of the electric field. Therefore, when viewing the liquid crystal on the first substrate 2 side as a whole, the liquid crystal molecules 60 are aligned in a convex arc shape toward the upper side (Z1 side) between the drive electrodes 261 and 262. This results in an arc-shaped dielectric constant distribution in the liquid crystal layer LC, causing incident light (polarized components parallel to the initial alignment direction of the liquid crystal molecules 60) to diffuse radially. Furthermore, as shown in FIG. 9C , a similar phenomenon occurs on the second substrate 3 side due to the drive electrodes 361 and 362, causing the polarized components of the incident light parallel to the initial alignment direction of the liquid crystal molecules 60 on the second substrate 3 side to diffuse radially. That is, the polarized light diffusing on the first substrate 2 side and the polarized light diffusing on the second substrate 3 side are rotated and change their polarization direction when passing through the liquid crystal layer LC, resulting in the same polarized light being diffused.

[0049] FIG. 10 is a diagram of the dimming panel viewed from above, with arrows indicating the direction of the electric field at the center of the liquid crystal layer in the thickness direction. When a high voltage is applied to the drive electrodes 261 and 262, the area where the arc-shaped electric field extends toward the Z1 side (upper side) shown in FIG. 9B expands further toward the Z1 side. When a high voltage is applied to the drive electrodes 361 and 362, the area where the arc-shaped electric field extends toward the Z2 side (lower side) shown in FIG. 9C expands further toward the Z2 side. Therefore, the area where the electric field extends due to the drive electrodes 261 and 262 intersects with the area where the electric field extends due to the drive electrodes 361 and 362 in the area of ​​the intermediate layer LC1 shown in FIG. 9B. As a result, as shown in FIG. 10, an electric field acts in the intermediate layer LC1 along a direction that intersects both the X and Y directions.

[0050] Next, a block diagram of the light control device 100 will be described. Fig. 11 is a block diagram of the light control device according to the first embodiment. As shown in Fig. 11, the light control device 100 according to the first embodiment includes an electrode drive circuit 112, a memory circuit 113, and a processing circuit 114 as a control block for controlling the panel unit 110 described above. The processing circuit 114 is configured with a microcomputer for executing light distribution control and dimming control of the light control device 100.

[0051] The electrode drive circuit 112 supplies voltage to each of the drive electrodes 261 , 262 , 361 , and 362 of each of the dimming panels 1 of the panel unit 110 based on the processing result in the processing circuit 114 .

[0052] The storage circuitry 113 includes, for example, an internal memory implemented in a microcomputer that constitutes the processing circuitry 114. In a storage area of ​​the storage circuitry 113, intermediate data of processing in the processing circuitry 114 is temporarily stored.

[0053] The memory circuit 113 also includes a setting circuit 1131. The setting circuit 1131 sets various setting items, such as the frequency and phase of the voltage supplied to each of the drive electrodes 261, 262, 361, and 362 of each dimming panel 1. The setting circuit 1131 is exemplified by, for example, a DIP switch (Dual In-line Package switch) that can set each setting item. In this case, the setting circuit 1131 is exemplified by a configuration that includes a plurality of two-state switch circuits, for example, "0" and "1".

[0054] Next, the voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side will be described. Fig. 12A is a diagram showing waveforms of the voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the first embodiment. Fig. 12B is a diagram showing the direction of the electric field at the center of the liquid crystal layer in the thickness direction with arrows during the first to fourth periods in Fig. 12A.

[0055] 12A, the voltages applied to the drive electrodes 261 and 262 on the first substrate 2 side and the voltages applied to the drive electrodes 361 and 362 on the second substrate 3 side have different frequencies but the same phase. This will be explained in detail below.

[0056] 12A , the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 60 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 90 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262.

[0057] Furthermore, the period from time t1 to time t2 is a first period TM1, the period from time t2 to time t3 is a second period TM2, the period from time t3 to time t4 is a third period TM3, and the period from time t4 to time t5 is a fourth period TM4.

[0058] As shown in FIG. 12A , during the first period TM1, the voltage applied to the drive electrode 361 is a low-level voltage VL, and the voltage applied to the drive electrode 362 is a high-level voltage VH. That is, pulse voltages having the same amplitude and opposite polarities to each other during the same period are applied to the two drive electrodes 361 and 362. Also, during the first period TM1, the voltage applied to the drive electrode 261 is a low-level voltage VL, and the voltage applied to the drive electrode 262 is a high-level voltage VH. That is, pulse voltages having the same amplitude and opposite polarities to each other during the same period are applied to the two drive electrodes 261 and 262. Therefore, during the first period TM1, the electric field direction is as shown in FIG. 12B .

[0059] 12A, during the second period TM2, the voltages applied to the drive electrodes 361 and 362 are the same as those applied to the first period TM1. However, the voltage applied to the drive electrode 261 changes from voltage VL to voltage VH at time t2, and the voltage applied to the drive electrode 262 changes from voltage VH to voltage VL at time t2. Therefore, as shown in FIG. 12B, the direction of the electric field during the second period TM2 is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field during the first period TM1.

[0060] 12A , the voltage applied to drive electrode 361 changes from voltage VL to voltage VH at time t3, and the voltage applied to drive electrode 362 changes from voltage VH to voltage VL at time t3. Furthermore, during third period TM3, the voltages applied to drive electrodes 261 and 262 are the same as those during second period TM2. Therefore, as shown in FIG. 12B , the direction of the electric field during third period TM3 is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field during second period TM2.

[0061] 12A, during the fourth period TM4, the voltages applied to the drive electrodes 361 and 362 are the same as those during the third period TM3. However, the voltage applied to the drive electrode 261 changes from voltage VH to voltage VL at time t4, and the voltage applied to the drive electrode 262 changes from voltage VL to voltage VH at time t4. Therefore, as shown in FIG. 12B, the direction of the electric field during the fourth period TM4 is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field during the third period TM3.

[0062] Fig. 13A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in a comparative example, and Fig. 13B is a diagram showing the direction of the electric field at the center of the liquid crystal layer in the thickness direction with arrows from the first period to the second period in Fig. 13A.

[0063] 13A , in the comparative example, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 60 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 60 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is the same as the frequency of the voltage applied to the drive electrodes 261 and 262.

[0064] In the first period TM1A, the voltage applied to the drive electrode 361 is a low-level voltage VL, and the voltage applied to the drive electrode 362 is a high-level voltage VH. Also, in the first period TM1A, the voltage applied to the drive electrode 261 is a low-level voltage VL, and the voltage applied to the drive electrode 262 is a high-level voltage VH.

[0065] In the second period TM2A, the voltage applied to the drive electrode 361 is voltage VH, and the voltage applied to the drive electrode 362 is voltage VL. Also, in the second period TM2A, the voltage applied to the drive electrode 261 is voltage VH, and the voltage applied to the drive electrode 262 is voltage VL. In this way, in all periods, the waveforms of the voltages applied to the drive electrodes 361 and 362 are the same as the waveforms of the voltages applied to the drive electrodes 261 and 262.

[0066] Therefore, as shown in FIG. 13B, the direction of the electric field is the same in all periods including the first period TM1A and the second period TM2A.

[0067] Next, the behavior of liquid crystal molecules when an electric field is applied will be described. Figure 14A is a schematic diagram showing the behavior of liquid crystal molecules when the electric field of Figure 12B is applied. Figure 14B is a schematic diagram showing the behavior of liquid crystal molecules when the electric field of Figure 13B is applied.

[0068] In FIG. 14A , the direction of the long axis of the liquid crystal molecules 60A when no voltage is applied is direction DR0. The direction of the electric field during the first period TM1 in FIG. 12B is direction DR1. The direction of the electric field during the second period TM2 in FIG. 12B is direction DR2. The crossing angle θ3 between the direction DR1 and the direction DR0 is, for example, 45 degrees. The crossing angle θ4 between the direction DR2 and the direction DR0 is, for example, 45 degrees. The direction of the electric field alternates between direction DR1 and direction DR2 in the order of the first period TM1, the second period TM2, the third period TM3, and the fourth period TM4. Furthermore, the liquid crystal molecules 60A when no voltage is applied are indicated by solid lines, the liquid crystal molecules 60A when the electric field is directed in direction DR1 are indicated by two-dot chain lines, and the liquid crystal molecules 60A when the electric field is directed in direction DR2 are indicated by dashed lines. When the electric field direction becomes direction DR1, the orientation of the long axes of the liquid crystal molecules 60A rotates toward direction DR1 by an angle θ1. However, when the electric field direction changes to direction DR2, the orientation of the long axes of the liquid crystal molecules 60A rotates toward direction DR2 by an angle θ2 with respect to direction DR0. The magnitudes of these angles θ1 and θ2 are smaller than the crossing angle θ3 or θ4.

[0069] In contrast, in the comparative example, the direction of the electric field in the first period TM1A in Fig. 13A is direction DR1, and the direction of the electric field in the second period TM2A is also direction DR1. That is, the direction of the electric field is the same in direction DR1 throughout all periods. Therefore, the liquid crystal molecules 60A gradually rotate toward direction DR1 and come to rest with their major axes facing direction DR1.

[0070] FIG. 15 is a graph showing changes in illuminance in the example and the comparative example. This illuminance is the illuminance in the on state where voltage is supplied to all of the dimming panels 1 of the panel unit 110 of the dimming device 100. As shown by the solid line in FIG. 15 , in the example, the illuminance remains substantially constant with almost no decrease even after a long time (e.g., 40 minutes) has passed. In contrast, in the comparative example shown by the dashed line, after about 10 minutes, the illuminance remains substantially constant at about 85%, which is about 15% lower than the initial illuminance. This demonstrates that the present embodiment suppresses the decrease in illuminance.

[0071] [Modification 1] Next, a description will be given of Modification 1. Fig. 16A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 1.

[0072] In Modification 1, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 60 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 30 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262.

[0073] A first period TM1B from time t1 to time t2 is, for example, 8.33 ms, and a second period TM2B from time t2 to time t3 is, for example, 8.33 ms, with all periods being the same 8.33 ms.

[0074] 16A , in a first period TM1B, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0075] In the second period TM2B, the voltage applied to the drive electrode 361 is voltage VH, and the voltage applied to the drive electrode 362 is voltage VL. The voltage applied to the drive electrode 261 is voltage VL, and the voltage applied to the drive electrode 262 is voltage VH.

[0076] [Modification 2] Next, a description will be given of Modification 2. Fig. 16B is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 2.

[0077] In Modification 2, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 50 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 60 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262.

[0078] The first period TM1C from time t1 to time t2 is, for example, 8.33 ms, the second period TM2C from time t2 to time t3 is, for example, 1.66 ms, the third period TM3C from time t3 to time t4 is, for example, 6.66 ms, the fourth period TM4C from time t4 to time t5 is, for example, 3.33 ms, and the fifth period TM5C from time t5 to time t6 is, for example, 5 ms.

[0079] 16B , in a first period TM1C, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0080] In the second period TM2C, the voltage applied to the drive electrode 361 is voltage VL, and the voltage applied to the drive electrode 362 is voltage VH. The voltage applied to the drive electrode 261 is voltage VH, and the voltage applied to the drive electrode 262 is voltage VL. From the third period TM3C onwards, the voltages applied to the respective drive electrodes are as shown in FIG. 16B.

[0081] [Modification 3] Next, a description will be given of Modification 3. Fig. 16C is a diagram showing waveforms of voltages respectively applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 3.

[0082] In Modification 3, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 60 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 80 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262.

[0083] The first period TM1D from time t1 to time t2 is, for example, 6.25 ms, the second period TM2D from time t2 to time t3 is, for example, 2.08 ms, and the third period TM3D from time t3 to time t4 is, for example, 4.16 ms. Note that the duration of each of these periods is preferably, for example, 8 ms or less.

[0084] 16C , in a first period TM1D, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0085] In the second period TM2D, the voltage applied to the drive electrode 361 is voltage VL, and the voltage applied to the drive electrode 362 is voltage VH. The voltage applied to the drive electrode 261 is voltage VH, and the voltage applied to the drive electrode 262 is voltage VL.

[0086] In the third period TM3D, the voltage applied to drive electrode 361 is voltage VH, and the voltage applied to drive electrode 362 is voltage VL. The voltage applied to drive electrode 261 is voltage VH, and the voltage applied to drive electrode 262 is voltage VL. From the fourth period TM4D onwards, the voltages applied to the respective drive electrodes are as shown in FIG. 16C .

[0087] [Modification 4] Next, a description will be given of Modification 4. Fig. 16D is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 4.

[0088] In Modification 4, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 110 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 120 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262.

[0089] The first period TM1E from time t1 to time t2 is, for example, 4.17 ms, the second period TM2E from time t2 to time t3 is, for example, 0.38 ms, the third period TM3E from time t3 to time t4 is, for example, 3.79 ms, the fourth period TM4E from time t3 to time t4 is, for example, 0.76 ms, the fifth period TM5E from time t4 to time t5 is, for example, 3.41 ms, and the sixth period TM6E from time t5 to time t6 is, for example, , for example, 1.14 ms, a seventh period TM7E from time t6 to time t7 is for example, 3.03 ms, an eighth period TM8E from time t7 to time t8 is for example, 1.52 ms, a ninth period TM9E from time t8 to time t9 is for example, 2.65 ms, a tenth period TM10E from time t9 to time t10 is for example, 1.89 ms, and an eleventh period TM11E from time t10 to time t11 is for example, 2.27 ms. Note that the duration of each of these periods is preferably, for example, 8 ms or less.

[0090] 16D , in a first period TM1E, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0091] In the second period TM2E, the voltage applied to the drive electrode 361 is voltage VL, and the voltage applied to the drive electrode 362 is voltage VH. The voltage applied to the drive electrode 261 is voltage VH, and the voltage applied to the drive electrode 262 is voltage VL.

[0092] In the third period TM3E, the voltage applied to drive electrode 361 is voltage VH, and the voltage applied to drive electrode 362 is voltage VL. The voltage applied to drive electrode 261 is voltage VH, and the voltage applied to drive electrode 262 is voltage VL. From the fourth period TM4E onwards, the voltages applied to the respective drive electrodes are as shown in FIG. 16D.

[0093] As described above, in the first embodiment and Modifications 1 to 4, the dimming device 100 includes a light source 630 and a panel unit 110 in which a plurality of dimming panels are stacked. At least one of the plurality of dimming panels 1 in the panel unit 110 includes a first substrate 2 on which electrodes are provided, a second substrate 3 on which electrodes are provided, and a liquid crystal layer LC. The voltages applied to the electrodes provided on the first substrate 2 and the voltages applied to the electrodes provided on the second substrate 3 have different frequencies. Furthermore, the electrodes provided on the first substrate 2 include a drive electrode 261 and a drive electrode 262, and the electrodes provided on the second substrate 3 include a drive electrode 361 and a drive electrode 362.

[0094] As mentioned above, in the dimming device of Patent Document 1, the alignment of the liquid crystal molecules arranged in the middle part of the thickness direction of the liquid crystal layer may become distorted, causing unintended diffusion, which may reduce the illuminance of the light emitted from the panel unit of the dimming device.

[0095] However, in the first embodiment and variants 1 to 4, the voltage applied to the drive electrodes 261 and 262 provided on the first substrate 2 and the voltage applied to the drive electrodes 361 and 362 provided on the second substrate 3 have different frequencies.

[0096] 14A, the direction of the electric field alternates between directions DR1 and DR2 in a short time in the intermediate layer LC1 (see FIGS. 9B and 9C) located in the middle portion of the liquid crystal layer LC in the thickness direction. When the direction of the electric field becomes direction DR1, the direction of the long axes of the liquid crystal molecules 60A rotates toward direction DR1, and when the direction of the electric field changes to direction DR2, the direction of the long axes of the liquid crystal molecules 60A rotates toward direction DR2.

[0097] However, because the rotational movement of the liquid crystal molecules 60A is slow, when the direction of the electric field changes to direction DR1, the liquid crystal molecules 60A begin to rotate toward direction DR1. However, because the direction of the electric field immediately changes to direction DR2, the liquid crystal molecules 60A begin to rotate toward direction DR2 while still rotating toward direction DR1. Therefore, as shown in FIG. 14A , the liquid crystal molecules 60A rotate (oscillate) within a range of angles θ1 and θ2 around direction DR0. Because the magnitudes of angles θ1 and θ2 are much smaller than the crossing angles θ3 and θ4, the liquid crystal molecules 60A maintain their orientation when no voltage is applied to the drive electrodes. Therefore, according to the first embodiment and Modifications 1 to 4, a light control device capable of suppressing a decrease in the illuminance of the emitted light can be provided.

[0098] [Second embodiment] Next, a second embodiment will be described. Fig. 17A is a diagram showing waveforms of voltages respectively applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the second embodiment. Fig. 17B is a diagram showing with arrows the direction of the electric field at the center in the thickness direction of the liquid crystal layer during the first to fourth periods in Fig. 17A.

[0099] 17A, the voltages applied to the drive electrodes 261, 262 on the first substrate 2 side and the voltages applied to the drive electrodes 361, 362 on the second substrate 3 side are different in phase and have the same frequency. This will be explained in detail below.

[0100] 17A, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 60 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 60 Hz. However, the phase of the voltage applied to the drive electrodes 361 and 362 is shifted by 90 degrees from the phase of the voltage applied to the drive electrodes 261 and 262.

[0101] 17A, in a first period TM1F from time t1 to time t2, the voltage applied to drive electrode 361 is voltage VL, and the voltage applied to drive electrode 362 is voltage VH. The voltage applied to drive electrode 261 is voltage VL, and the voltage applied to drive electrode 262 is voltage VH. Therefore, in the first period TM1F, the electric field has a direction as shown in FIG. 17B.

[0102] In the second period TM2F, the voltage applied to the driving electrode 361 is voltage VH, and the voltage applied to the driving electrode 362 is voltage VL. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH. Therefore, as shown in Fig. 17B, the direction of the electric field in the second period TM2F is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field in the first period TM1F.

[0103] Note that from the third period TM3F onwards, the voltages applied to the respective drive electrodes are as shown in Fig. 17A. Therefore, as shown in Fig. 17B, the direction of the electric field in the third period TM3F is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field in the second period TM2F, and the direction of the electric field in the fourth period TM4F is rotated 90 degrees clockwise as viewed from the Z direction with respect to the direction of the electric field in the third period TM3F.

[0104] As described above, according to the second embodiment, the voltages applied to the drive electrodes 261 and 262 are out of phase with the voltages applied to the drive electrodes 361 and 362. As a result, similar to the case where different frequencies are applied to the drive electrodes in the first embodiment, as shown in FIG. 14A , the liquid crystal molecules 60A located in the intermediate layer LC1 (see FIGS. 9B and 9C ) rotate (oscillate) within angles θ1 and θ2 around the direction DR0. Because the angles θ1 and θ2 are much smaller than the crossing angle θ3 or the crossing angle θ4, the liquid crystal molecules 60A located in the intermediate layer LC1 maintain their posture when no voltage is applied to the drive electrodes. Therefore, according to the second embodiment, a light control device capable of suppressing a decrease in the illuminance of emitted light can be provided.

[0105] Third Embodiment Next, a third embodiment will be described. Fig. 18A is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in the third embodiment.

[0106] In the third embodiment, the voltage applied to the drive electrodes 361 and 362 on the second substrate side and the voltage applied to the drive electrodes 261 and 262 on the first substrate side differ in both frequency and phase.

[0107] Specifically, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 50 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 60 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262. In addition, the phase of the voltage applied to the drive electrodes 361 and 362 is shifted by 90 degrees from the phase of the voltage applied to the drive electrodes 261 and 262.

[0108] The first period TM1G from time t1 to time t2 is, for example, 5 ms, the second period TM2G from time t2 to time t3 is, for example, 3.33 ms, the third period TM3G from time t3 to time t4 is, for example, 6.67 ms, the fourth period TM4G from time t4 to time t5 is, for example, 1.67 ms, and the fifth period TM5G from time t5 to time t6 is, for example, 8.33 ms.

[0109] 18A , in a first period TM1G, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0110] In the second period TM2G, the voltage applied to the drive electrode 361 is voltage VH, and the voltage applied to the drive electrode 362 is voltage VL. The voltage applied to the drive electrode 261 is voltage VL, and the voltage applied to the drive electrode 262 is voltage VH. From the third period TM3G onwards, the voltages applied to the respective drive electrodes are as shown in FIG. 18A.

[0111] [Modification 5] Next, a description will be given of Modification 5. Fig. 18B is a diagram showing waveforms of voltages applied to the drive electrodes on the first substrate side and the drive electrodes on the second substrate side in Modification 5.

[0112] In the fifth modification, the voltage applied to the drive electrodes 361 and 362 on the second substrate side and the voltage applied to the drive electrodes 261 and 262 on the first substrate side differ in both frequency and phase.

[0113] Specifically, the voltage applied to the drive electrodes 361 and 362 on the second substrate side has a frequency of 50 Hz, and the voltage applied to the drive electrodes 261 and 262 on the first substrate side has a frequency of 60 Hz. In this way, the frequency of the voltage applied to the drive electrodes 361 and 362 is different from the frequency of the voltage applied to the drive electrodes 261 and 262. In addition, the phase of the voltage applied to the drive electrodes 361 and 362 is shifted by 45 degrees from the phase of the voltage applied to the drive electrodes 261 and 262.

[0114] The first period TM1H from time t1 to time t2 is, for example, 7.5 ms, the second period TM2H from time t2 to time t3 is, for example, 0.83 ms, the third period TM3H from time t3 to time t4 is, for example, 8.83 ms, the fourth period TM4H from time t4 to time t5 is, for example, 0.83 ms, the fifth period TM5H from time t5 to time t6 is, for example, 7.5 ms, the sixth period TM6H from time t6 to time t7 is, for example, 2.5 ms, the seventh period TM7H from time t7 to time t8 is, for example, 5.83 ms, and the eighth period TM8H from time t8 to time t9 is, for example, 4.17 ms.

[0115] 18B , in a first period TM1H, the voltage applied to the driving electrode 361 is voltage VL, and the voltage applied to the driving electrode 362 is voltage VH. The voltage applied to the driving electrode 261 is voltage VL, and the voltage applied to the driving electrode 262 is voltage VH.

[0116] In the second period TM2H, the voltage applied to the drive electrode 361 is voltage VH, and the voltage applied to the drive electrode 362 is voltage VL. The voltage applied to the drive electrode 261 is voltage VL, and the voltage applied to the drive electrode 262 is voltage VH. From the third period TM3H onwards, the voltages applied to the respective drive electrodes are as shown in FIG. 18B.

[0117] As described above, according to the third embodiment and modified example 5, the voltage applied to the drive electrodes 261 and 262 differs in frequency and phase from the voltage applied to the drive electrodes 361 and 362. As a result, as shown in Fig. 14A , the liquid crystal molecules 60A located in the intermediate layer LC1 (see Figs. 9B and 9C ) rotate (oscillate) within the range of angles θ1 and θ2 around the direction DR0, making it possible to provide a light control device that can suppress a decrease in the illuminance of the emitted light.

[0118] [Fourth embodiment] Next, the connection state of four dimming panels will be described. Fig. 19A is a schematic diagram of a first embodiment showing wiring connecting four dimming panels. Fig. 19B is a schematic diagram showing the correspondence between the first and second substrates of the four dimming panels shown in Fig. 7 and Fig. 19A.

[0119] 19A , the first terminal 101 of the first dimming panel 1A and the seventh terminal 203 of the fourth dimming panel 1D are electrically connected via wiring. The second terminal 102 of the first dimming panel 1A and the eighth terminal 204 of the fourth dimming panel 1D are electrically connected via wiring. The third terminal 103 of the first dimming panel 1A and the fifth terminal 201 of the fourth dimming panel 1D are electrically connected via wiring. The fourth terminal 104 of the first dimming panel 1A and the sixth terminal 202 of the fourth dimming panel 1D are electrically connected via wiring.

[0120] Furthermore, the first terminal 101 of the second dimming panel 1B and the seventh terminal 203 of the third dimming panel 1C are electrically connected via wiring. The second terminal 102 of the second dimming panel 1B and the eighth terminal 204 of the third dimming panel 1C are electrically connected via wiring. The third terminal 103 of the second dimming panel 1B and the fifth terminal 201 of the third dimming panel 1C are electrically connected via wiring. The fourth terminal 104 of the second dimming panel 1B and the sixth terminal 202 of the third dimming panel 1C are electrically connected via wiring. To briefly summarize the above, the configuration is as shown in FIG. 19B .

[0121] 19B , the first group G1 includes the second substrate S42 (second substrate 3) and the first substrate S11 (first substrate 2). The two substrates included in the first group G1 are electrically connected. The second group G2 includes the second substrate S32 (second substrate 3) and the first substrate S21 (first substrate 2). The two substrates included in the second group G2 are electrically connected.

[0122] The third group G3 includes a first substrate S41 (first substrate 2) and a second substrate S12 (second substrate 3). The two substrates included in the third group G3 are electrically connected. The fourth group G4 includes a first substrate S31 (first substrate 2) and a second substrate S22 (second substrate 3). The two substrates included in the fourth group G4 are electrically connected.

[0123] Fig. 20A is a schematic diagram of a second embodiment showing wiring connecting four dimming panels. Fig. 20B is a schematic diagram showing the correspondence between the first and second substrates of the four dimming panels shown in Fig. 7 and Fig. 20A.

[0124] 20A , the first terminal 101 of the first dimming panel 1A and the seventh terminal 203 of the third dimming panel 1C are electrically connected via wiring. The second terminal 102 of the first dimming panel 1A and the eighth terminal 204 of the third dimming panel 1C are electrically connected via wiring. The third terminal 103 of the first dimming panel 1A and the fifth terminal 201 of the third dimming panel 1C are electrically connected via wiring. The fourth terminal 104 of the first dimming panel 1A and the sixth terminal 202 of the third dimming panel 1C are electrically connected via wiring.

[0125] Furthermore, the first terminal 101 of the second dimming panel 1B and the seventh terminal 203 of the fourth dimming panel 1D are electrically connected via wiring. The second terminal 102 of the second dimming panel 1B and the eighth terminal 204 of the fourth dimming panel 1D are electrically connected via wiring. The third terminal 103 of the second dimming panel 1B and the fifth terminal 201 of the fourth dimming panel 1D are electrically connected via wiring. The fourth terminal 104 of the second dimming panel 1B and the sixth terminal 202 of the fourth dimming panel 1D are electrically connected via wiring. To briefly summarize the above, the configuration is as shown in FIG. 20B .

[0126] Specifically, as shown in FIG. 20B , the fifth group G5 includes the second substrate S42 (second substrate 3) and the first substrate S21 (first substrate 2). The two substrates included in the fifth group G5 are electrically connected. The sixth group G6 includes the first substrate S41 (first substrate 2) and the second substrate S22 (second substrate 3). The two substrates included in the fifth group G5 are electrically connected.

[0127] The seventh group G7 includes the second substrate S32 (second substrate 3) and the first substrate S11 (first substrate 2). The two substrates included in the seventh group G7 are electrically connected. The eighth group G8 includes the first substrate S31 (first substrate 2) and the second substrate S12 (second substrate 3). The two substrates included in the eighth group G8 are electrically connected.

[0128] As described above, the first substrate 2 and the second substrate 3 are electrically connected in each of the four dimming panels 1. Therefore, it is possible to apply a voltage to all of the four dimming panels 1 by simply applying a voltage to two of the four dimming panels 1, without applying a voltage to each of the four dimming panels 1.

[0129] REFERENCE SIGNS LIST 1 Dimming panel 1A First dimming panel (dimming panel) 1B Second dimming panel (dimming panel) 1C Third dimming panel (dimming panel) 1D Fourth dimming panel (dimming panel) 2 First substrate 3 Second substrate 100 Dimming device 110 Panel unit 261 Drive electrode (first drive electrode) 262 Drive electrode (second drive electrode) 361 Drive electrode (third drive electrode) 362 Drive electrode (fourth drive electrode) 630 Light source AA Active area LC Liquid crystal layer

Claims

1. A light control device comprising a light source and a panel unit in which a plurality of light control panels are stacked in a first direction, wherein at least one of the plurality of light control panels in the panel unit has a first substrate provided with an electrode, a second substrate overlapping the first substrate in the first direction and provided with an electrode, and a liquid crystal layer filled between the first substrate and the second substrate, wherein at least one of the frequency and phase of the voltage applied to the electrode provided on the first substrate and the voltage applied to the electrode provided on the second substrate differ.

2. The light control device according to claim 1, wherein the electrodes provided on the first substrate include a first drive electrode and a second drive electrode arranged adjacent to the first drive electrode, and the electrodes provided on the second substrate include a third drive electrode and a fourth drive electrode arranged adjacent to the third drive electrode.

3. The light control device according to claim 2, wherein the voltages applied to the first and second drive electrodes and the voltages applied to the third and fourth drive electrodes have different frequencies.

4. The light control device according to claim 2, wherein the voltages applied to the first drive electrodes and the second drive electrodes and the voltages applied to the third drive electrodes and the fourth drive electrodes are out of phase with each other.

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