Light control device and lighting device

Abstract

A light control device 30 includes a liquid crystal element 40 that transmits and emits incident light L2 incident along a first direction D1, and a second lens 70 on which an emission light L3 of the liquid crystal element 40 is incident. A first region A1 of the liquid crystal element 40 emits the emission light L3 along the first direction D1 when a potential is not applied and emits the emission light L3 along a second direction D2, which is different from the first direction D1, when the potential is applied. A second region A2 of the liquid crystal element 40 emits the emission light L3 along the first direction D1. The second lens 70 has a reflection surface 72 that totally reflects the emission light L3 that is incident along the first direction D1 along a third direction D3 toward a second emission surface 73 and refracts and emits the emission light L3 that is incident along the second direction D2 along a fourth direction D4 away from the second emission surface 73.

Description

Light control device and lighting device

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

[0002] Patent Document 1 discloses, as an example of a light control device, a vehicle headlamp capable of controlling an illumination area (illumination range). The vehicle headlamp of Patent Document 1 includes a light source, a polarizing beam splitter, a reflector, and a liquid crystal element. Light from the light source is split into two polarized lights by the polarizing beam splitter. One of the two polarized lights is reflected by the polarizing beam splitter and directed toward the liquid crystal element. The other of the two polarized lights passes through the polarizing beam splitter, is reflected by the reflector, and directed toward the liquid crystal element. In other words, the two polarized lights are collected by the liquid crystal element. This improves the utilization efficiency of the light from the light source.

[0003] JP 2019-50134 A

[0004] In the light control device of Patent Document 1, the direction of polarization must be precisely adjusted before it is incident on the liquid crystal element. The direction of polarization changes depending on the dimensional variations of each component and the arrangement of each component. Therefore, the light control device of Patent Document 1 requires a relatively high degree of precision in the dimensions and arrangement of each component. Therefore, it is difficult to easily switch the illumination range.

[0005] The present disclosure aims to provide a light control device that can easily switch the illumination range.

[0006] The light control device of the present disclosure includes a first substrate, a second substrate, and a liquid crystal layer between the first substrate and the second substrate, and includes a liquid crystal element that transmits and emits incident light that is incident along a first direction, and a lens having a first surface on which the emitted light of the liquid crystal element is incident and that diffuses and emits the emitted light, wherein the liquid crystal element has a first region in which a third electrode that overlaps with the electric resistance film in a plan view is arranged on the second substrate, and a second region in which the electric resistance film is not arranged, and The first region of the liquid crystal element emits the emitted light along the first direction when no potential is applied to the element group and the third electrode, and emits the emitted light along a second direction different from the first direction when a potential is applied to the element group and the third electrode, the second region of the liquid crystal element emits the emitted light along the first direction, and the lens further has a second surface that totally reflects the emitted light incident along the first direction along a third direction toward the first surface, and refracts the emitted light incident along the second direction along a fourth direction away from the first surface.

[0007] An illumination device according to the present disclosure includes the above-described light control device and a light source that emits light incident on the light control device.

[0008] Fig. 1 is a diagram showing the configuration of an illumination device according to an embodiment of the present disclosure. Fig. 2 is a plan view of a liquid crystal element. Fig. 3 is a cross-sectional view of the liquid crystal element taken along line III-III shown in Fig. 2. Fig. 4 is a diagram showing the potential of an electrically resistive film when the liquid crystal element refracts incident light, and the phase difference of incident light passing through a liquid crystal layer. Fig. 5 is a diagram showing a first illumination range. Fig. 6 is a diagram showing a second illumination range. Fig. 7 is a diagram showing a third illumination range illuminated by an illumination device according to a modified embodiment of the present disclosure.

[0009] Each embodiment of the present disclosure will be described below 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 the same. 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 present 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 given the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] The X and Y directions shown in the drawings correspond to directions parallel to the plate surfaces of the substrates of the liquid crystal element described below. The Z direction corresponds to the thickness direction of the liquid crystal element. The X, Y, and Z directions are perpendicular to each other. In this specification, "planar view" means viewing the liquid crystal element along the Z direction. Note that the X, Y, and Z directions are merely examples, and the present disclosure is not limited to these directions.

[0012] 1 is a diagram illustrating the configuration of an illumination device 1 according to an embodiment of the present disclosure. The illumination device 1 is, for example, a vehicle headlight or a spotlight. The illumination device 1 includes a light source 10, a first lens 20, and a light control device 30. The light control device 30 includes a liquid crystal element 40 and a second lens 70 (corresponding to "lens").

[0013] The light source 10 emits light L1 that is incident on the light control device 30. Specifically, the light L1 from the light source 10 is incident on the liquid crystal element 40 via a first lens 20. The light source 10 is, for example, an LED (light emitting diode).

[0014] The first lens 20 is an optical element that collimates the traveling direction of the light L1 from the light source 10. The first lens 20 is a collimating lens. The first lens 20 converts the incident light L2 that is incident on the liquid crystal element 40 into parallel light and outputs the parallel light.

[0015] The liquid crystal element 40 is a refracting plate that refracts the incident light L2. The liquid crystal element 40 has a first incident surface 40a (surface on the -Z side) on which the incident light L2 is incident. The direction in which the incident light L2 (parallel light) travels is defined as a first direction D1. The first direction D1 is parallel to the Z direction. The liquid crystal element 40 transmits and emits the incident light L2 that is incident along the first direction D1.

[0016] Fig. 2 is a plan view of the liquid crystal element 40. Fig. 3 is a cross-sectional view of the liquid crystal element 40 taken along line III-III shown in Fig. 2. The first incident surface 40a has an incident area LA onto which incident light L2 is incident.

[0017] 3, the liquid crystal element 40 includes a first substrate 41, a second substrate 42, and a liquid crystal layer 43 between the first substrate 41 and the second substrate 42. The first substrate 41 and the second substrate 42 are light-transmitting. The first substrate 41 and the second substrate 42 are, for example, glass substrates, resin substrates, or resin films.

[0018] As shown in FIG. 2, the incident area LA of the liquid crystal element 40 has a first area A1 and a second area A2.

[0019] The first region A1 is located on the -Y side of the incident region LA. The first region A1 has four sides in a plan view and is substantially trapezoidal. Of the four sides, the first side S1 and the second side S2 extend along the X direction and face each other in the Y direction. The first side S1 is shorter than the second side S2. The third side S3 extends along the Y direction and connects the first side S1 and the second side S2 on the -X side. The fourth side S4 extends from the +X side end of the first side S1 in a direction inclined with respect to the X and Y directions and faces the second side S2 in the Y direction.

[0020] The second region A2 is a region of the incident region LA other than the first region A1 in a plan view.

[0021] As shown in FIGS. 2 and 3, a plurality of element sets 50 and a third electrode 60 are arranged in the first region A1.

[0022] Specifically, a plurality of element groups 50 are arranged on the first substrate 41. Each element group 50 includes an electrically resistive film 51, a first electrode 52, and a second electrode 53.

[0023] The resistive film 51 has a strip shape extending in the Y direction in a plan view. The resistive film 51 is made of a transparent conductive material such as indium gallium zinc oxide (IGZO). The resistive film 51 has a higher electrical resistance than the first electrode 52 and the second electrode 53.

[0024] The first electrode 52 and the second electrode 53 are electrically connected to the electrical resistance film 51 .

[0025] The first electrode 52 extends in the Y direction in plan view and overlaps with the electrical resistance film 51 on the first end side (+X side) of the electrical resistance film 51 in the X direction. The first electrode 52 is in contact with the electrical resistance film 51.

[0026] The second electrode 53 extends in the Y direction in plan view and overlaps with the electrical resistance film 51 on the second end side (−X side) of the electrical resistance film 51 in the X direction. The second electrode 53 is in contact with the electrical resistance film 51.

[0027] The first electrode 52 and the second electrode 53 overlap the electrical resistance film 51 while facing each other in the X direction in a plan view.

[0028] In the electrically resistive film 51, a portion overlapping with the first electrode 52 in a planar view is referred to as a first overlapping portion 51a, a portion overlapping with the second electrode 53 in a planar view is referred to as a second overlapping portion 51b, and a portion between the first overlapping portion 51a and the second overlapping portion 51b is referred to as an intermediate portion 51c. In the X direction, the length of the intermediate portion 51c is longer than the combined length of the first overlapping portion 51a and the second overlapping portion 51b.

[0029] In this embodiment, in the X direction, the +X side end of the electrical resistance film 51 coincides with the +X side end of the first electrode 52, and the −X side end of the electrical resistance film 51 coincides with the −X side end of the second electrode 53, but they do not have to coincide with each other.

[0030] The plurality of element groups 50 are aligned along the X direction. As described above, the plurality of element groups 50 include strip-shaped electrically resistive films 51 extending along the Y direction. The plurality of element groups 50 are aligned along the X direction with two adjacent electrically resistive films 51 in the X direction spaced apart from each other.

[0031] 2, in a plan view, the plurality of electrical resistance films 51 overlap with the first region A1. The Y-direction lengths of the plurality of electrical resistance films 51 between the first side S1 and the second side S2 are the same. The Y-direction lengths of the plurality of electrical resistance films 51 between the fourth side S4 and the second side S2 become shorter from the −X side toward the +X side.

[0032] Similarly, the Y-direction lengths of the first electrodes 52 between the first side S1 and the second side S2 are the same. Furthermore, the Y-direction lengths of the first electrodes 52 between the fourth side S4 and the second side S2 become shorter from the −X side toward the +X side.

[0033] Similarly, the Y-direction lengths of the second electrodes 53 between the first side S1 and the second side S2 are the same, and the Y-direction lengths of the second electrodes 53 between the fourth side S4 and the second side S2 become shorter from the −X side to the +X side.

[0034] The liquid crystal element 40 includes a plurality of first connection members 54 that electrically connect two adjacent first electrodes 52. Hereinafter, a first connection member 54 and two first electrodes 52 electrically connected to the first connection members 54 will be referred to as a set of first electrodes C1. Figure 2 shows three sets of first electrodes C1 and one first electrode 52. It goes without saying that the number of sets of first electrodes C1 and first electrodes 52 is not limited to the number shown in Figure 2.

[0035] The liquid crystal element 40 also includes a plurality of second connection members 55 that electrically connect two adjacent second electrodes 53. Hereinafter, a second connection member 55 and two second electrodes 53 electrically connected to the second connection members 55 will be referred to as a set of second electrodes C2. Figure 2 shows three sets of second electrodes C2 and one second electrode 53. It goes without saying that the number of sets of second electrodes C2 and second electrodes 53 is not limited to the number shown in Figure 2.

[0036] 3, an insulating layer IL and a first alignment film AL1 are disposed on the first substrate 41. The plurality of electrically resistive films 51 are electrically insulated from one another by the insulating layer IL. The first alignment film AL1 is disposed on the +Z side in the Z direction relative to the plurality of element groups 50 and the insulating layer IL.

[0037] A third electrode 60 and a second alignment film AL2 are disposed on the second substrate 42. The second alignment film AL2 is disposed on the −Z side of the third electrode 60 in the Z direction.

[0038] The third electrode 60 overlaps the plurality of electrically resistive films 51 in plan view. As shown in Fig. 2, the third electrode 60 overlaps the first region A1 in plan view. The third electrode 60 has a trapezoidal shape.

[0039] The first electrode 52, the second electrode 53, and the third electrode 60 are made of a conductive material having light-transmitting properties, such as ITO (indium tin oxide), IZO (indium zinc oxide), IGO (indium gallium oxide), or IGZO (indium gallium zinc oxide).

[0040] 3, the liquid crystal layer 43 is sandwiched between a first alignment film AL1 and a second alignment film AL2. The liquid crystal layer 43 is disposed in a first region A1. The liquid crystal layer 43, the insulating layer IL, the first alignment film AL1, and the second alignment film AL2 overlap with the first region A1 in a plan view and have a substantially trapezoidal shape similar to the first region A1. A sealing member is disposed around the liquid crystal layer 43 in a plan view.

[0041] The first alignment film AL1 and the second alignment film AL2 determine the alignment (initial alignment) of the liquid crystal molecules LM contained in the liquid crystal layer 43 when no voltage is applied to the liquid crystal element 40. In the initial alignment of the liquid crystal molecules LM, the long axes of the liquid crystal molecules LM are perpendicular to the Z direction. The alignment direction of the first alignment film AL1 and the alignment direction of the second alignment film AL2 are perpendicular to each other in a planar view.

[0042] The liquid crystal element 40 is a twisted nematic (TN) liquid crystal element, although it goes without saying that the liquid crystal element 40 is not limited to a twisted nematic liquid crystal element.

[0043] In the second region A2, the liquid crystal layer 43 is not disposed between the first substrate 41 and the second substrate 42. That is, in a plan view, the liquid crystal layer 43 overlaps the first region A1 and is isolated from the second region A2. Furthermore, in the second region A2, the insulating layer IL, the first alignment film AL1, the second alignment film AL2, and the electrically resistive film 51 are not disposed between the first substrate 41 and the second substrate 42. In the second region A2, a resin member 46 is disposed between the first substrate 41 and the second substrate 42.

[0044] The refractive index of the resin member 46 is substantially the same as the refractive index of the first substrate 41 and the second substrate 42. This makes it possible to suppress deterioration of optical characteristics in the second region A2. Note that the resin member 46 does not have to be disposed between the first substrate 41 and the second substrate 42 in the second region A2. In this case, an air layer is formed between the first substrate 41 and the second substrate 42 in the second region A2. Furthermore, a liquid crystal layer 43 may be disposed between the first substrate 41 and the second substrate 42 in the second region A2.

[0045] Next, a description will be given of the operation of refracting incident light L2 by the liquid crystal element 40. As shown in Fig. 1, incident light L2 enters the first entrance surface 40a of the liquid crystal element 40 along the first direction D1.

[0046] In the second region A2, the liquid crystal layer 43 is not disposed, and the liquid crystal element 40 does not refract the incident light L2. That is, in the second region A2 of the liquid crystal element 40, the incident light L2 passes through without being refracted and is emitted from the first emission surface 40b (the surface on the +Z side). That is, the emission light L3 emitted by the liquid crystal element 40 in the second region A2 is along the first direction D1. Hereinafter, the emission light L3 emitted by the liquid crystal element 40 in the first direction D1 will be referred to as the first emission light L3a.

[0047] Furthermore, when no potential is applied to the plurality of element groups 50 and the third electrode 60 in the first region A1, the liquid crystal molecules LM of the liquid crystal layer 43 remain in their initial orientation, and the liquid crystal element 40 does not refract the incident light L2. In other words, in this case, no phase difference is generated in the first region A1 of the liquid crystal element 40, and the incident light L2 passes through without being refracted, and is emitted as the first outgoing light L3a from the first outgoing surface 40b.

[0048] On the other hand, when a potential is applied to the plurality of element groups 50 and the third electrode 60 in the first region A1, the incident light L2 is refracted in the first region A1 of the liquid crystal element 40, as described below, and is emitted from the first emission surface 40b along a second direction D2. The second direction D2 is a direction different from the first direction D1. Specifically, the second direction D2 is a direction inclined toward the +X side from the first direction D1 (Z direction). Hereinafter, the emitted light L3 along the second direction D2 emitted by the liquid crystal element 40 will be referred to as second emitted light L3b. Note that when the first emitted light L3a and the second emitted light L3b are described without distinction, they will simply be referred to as "emitted light L3."

[0049] FIG. 4 is a diagram showing the potential of the electrical resistance film 51 when the liquid crystal element 40 refracts the incident light L2 and the phase difference of the incident light L2 passing through the liquid crystal layer 43.

[0050] 4 represents the position (coordinate) in the X direction. The arrows corresponding to the symbols in parentheses in FIG. 4 indicate the range of the portion of the electrical resistance film 51.

[0051] When the liquid crystal element 40 refracts the incident light L2, a control circuit (not shown) applies a first potential E1 to the first electrode 52 and a second potential E2 higher than the first potential E1 to the second electrode 53. The first potential E1 is also applied to the third electrode 60. The first potential E1 is, for example, a reference potential of the control circuit.

[0052] In this case, in one electrical resistance film 51, the potential of the second overlapping portion 51b in contact with the second electrode 53 is equal to the second potential E2. In addition, in one electrical resistance film 51, the potential of the intermediate portion 51c between the first electrode 52 and the second electrode 53 changes linearly from the second potential E2 to the first potential E1 from the negative side to the positive side in the X direction. Furthermore, in one electrical resistance film 51, the potential of the first overlapping portion 51a in contact with the first electrode 52 is equal to the first potential E1.

[0053] The potential difference between the first potential E1 and the second potential E2 is determined based on the angle between the first direction D1 and the second direction D2. In other words, the angle between the first direction D1 and the second direction D2 can be adjusted by the potential difference between the first potential E1 and the second potential E2.

[0054] An electric field generated by applying a potential to the first electrode 52, the second electrode 53, and the third electrode 60 acts on the liquid crystal layer 43, tilting the liquid crystal molecules LM. This changes the refractive index of the liquid crystal layer 43 in the X direction, causing a phase difference in the incident light L2 passing through the liquid crystal layer 43.

[0055] 4, the phase at a position corresponding to the end of one electrical resistance film 51 closest to the −X side in the X direction (i.e., the end of the second overlapping portion 51b closest to the −X side) is taken as a reference (i.e., the phase difference is 0 (zero)), and the maximum value of the phase difference caused by the potential of the electrical resistance film 51 when the first electrode 52 and the second electrode 53 are applied is taken as a maximum phase difference R. Note that the solid line showing the phase difference of the incident light L2 shown in FIG. 4 indicates a locus of the same phase as the reference phase.

[0056] The phase difference of the incident light L2 passing through the liquid crystal layer 43 varies in a zigzag pattern along the X direction between 0 (zero) and the maximum phase difference R. Specifically, the phase difference in the portion of the liquid crystal layer 43 corresponding to the second overlapping portion 51b is 0 (zero). The phase difference in the portion of the liquid crystal layer 43 corresponding to the intermediate portion 51c varies linearly from 0 (zero) to the maximum phase difference R from the −X side to the +X side in the X direction. Furthermore, the phase difference in the portion of the liquid crystal layer 43 corresponding to the first overlapping portion 51a is the maximum phase difference R.

[0057] The phase difference between two adjacent electrical resistance films 51 in the X direction changes linearly from the maximum phase difference R to 0 (zero) from the −X side to the +X side in the X direction.

[0058] The degree of inclination of the phase difference in the portion of the liquid crystal layer 43 corresponding to the intermediate portion 51 c corresponds to the angle between the first direction D1 and the second direction D2. In addition, in the X direction, the length of the portion of the liquid crystal layer 43 corresponding to the intermediate portion 51 c is longer than the combined length of the portions of the liquid crystal layer 43 corresponding to the first overlapping portion 51 a and the second overlapping portion 51 b.

[0059] As shown in Figure 4, the phase difference of the incident light L2 passing through the liquid crystal layer 43 changes, so that the incident light L2 is refracted in the liquid crystal layer 43 and is emitted from the liquid crystal element 40 as second outgoing light L3b along the second direction D2.

[0060] In this way, the first region A1 of the liquid crystal element 40 can refract the incident light L2 with a simple configuration.

[0061] 1 receives the outgoing light L3 from the liquid crystal element 40, and diffuses the incident outgoing light L3 before emitting it. The second lens 70 has a second incident surface 71, a reflecting surface 72 (corresponding to the "second surface"), and a second outgoing surface 73 (corresponding to the "first surface").

[0062] The outgoing light L3 is incident on the second incident surface 71. The second incident surface 71 is disposed away from the first exit surface 40b of the liquid crystal element 40. The second incident surface 71 may be in contact with the first exit surface 40b. In this case, the liquid crystal element 40 and the second lens 70 are integrated.

[0063] The reflecting surface 72 is inclined with respect to the second incident surface 71. The degree of inclination of the reflecting surface 72 with respect to the second incident surface 71 is determined as follows: The reflecting surface 72 totally reflects the first outgoing light L3a incident along the first direction D1 along a third direction D3 toward the second outgoing surface 73. The reflecting surface 72 also refracts the second outgoing light L3b incident along the second direction D2 so that the second outgoing light L3b exits from the second outgoing surface 73 along a fourth direction D4.

[0064] The second exit surface 73 diffuses the first exit light L3a that has been totally reflected by the reflecting surface 72 and emits the diffused light as light L4. The second exit surface 73 has a spherical shape. The light L4 is light that is emitted from the lighting device 1.

[0065] Next, the operation of the lighting device 1 will be described assuming that the lighting device 1 is a vehicle headlight. The control circuit sets the range illuminated by the lighting device 1 to one of the first lighting range H1 and the second lighting range H2.

[0066] 5 is a diagram showing the first illumination range H1. Light L4 emitted by the illumination device 1 corresponding to the first illumination range H1 corresponds to a so-called high beam.

[0067] The W1 direction shown in the figure corresponds to the vertical direction. The +W1 side of the W1 direction corresponds to the upper side in the vertical direction. The -W1 side of the W1 direction corresponds to the lower side in the vertical direction. The W2 direction corresponds to the left and right directions when a vehicle occupant faces the direction of travel of the vehicle. The -W2 side of the W2 direction is the lane side on which the vehicle to which the lighting device 1 is applied is traveling. On the other hand, the +W2 side of the W2 direction is the lane side on which oncoming vehicles are traveling.

[0068] When the range illuminated by the lighting device 1 is the first illumination range H1, the control circuit does not apply a potential to the element set 50 and the third electrode 60. In this case, the first outgoing light L3a along the first direction D1 is emitted from both the first region A1 and the second region A2 of the liquid crystal element 40 as described above.

[0069] 1, the first outgoing light L3a is totally reflected by the reflecting surface 72 toward the second outgoing surface 73 and is emitted from the second outgoing surface 73 as light L4. The light L4 is emitted to the outside of the vehicle. That is, the first outgoing light L3a emitted from the first region A1 and the second region A2 of the liquid crystal element 40 is emitted to the outside of the vehicle. The range illuminated by the light L4 corresponds to the first illumination range H1.

[0070] 5, a first partial range HA of the first illumination range H1 indicated by a dashed line is a range corresponding to the first emitted light L3a emitted from the first region A1 of the liquid crystal element 40. Furthermore, a second partial range HB of the first illumination range H1 indicated by a dashed two-dot line is a range corresponding to the first emitted light L3a emitted from the second region A2 of the liquid crystal element 40. The first illumination range H1 is a range that combines the first partial range HA and the second partial range HB.

[0071] 6 is a diagram showing the second illumination range H2. The light L4 emitted by the illumination device 1 corresponding to the second illumination range H2 corresponds to a so-called low beam. In other words, the second illumination range H2 is defined as a range that does not illuminate oncoming vehicles.

[0072] When the range illuminated by the lighting device 1 is set to the second lighting range H2, the control circuit applies a potential to the plurality of element groups 50 and the third electrode 60. In this case, as described above, the first outgoing light L3a is emitted from the second region A2 of the liquid crystal element 40 along the first direction D1. Also, as described above, the second outgoing light L3b is emitted from the first region A1 of the liquid crystal element 40 along the second direction D2.

[0073] In the second lens 70, the first outgoing light L3a emitted from the second region A2 of the liquid crystal element 40 is totally reflected by the reflecting surface 72 toward the second outgoing surface 73, and is emitted as light L4 from the second outgoing surface 73. In other words, the first outgoing light L3a emitted from the second region A2 of the liquid crystal element 40 is emitted as light L4 toward the outside of the vehicle.

[0074] On the other hand, in the second lens 70, the second outgoing light L3b emitted from the first region A1 of the liquid crystal element 40 is refracted at the reflecting surface 72 and is emitted from the second lens 70. The second outgoing light L3b emitted from the reflecting surface 72 is not emitted to the outside of the vehicle.

[0075] In this case, the range illuminated by light L4 corresponds to the second illumination range H2. The second illumination range H2 is the range corresponding to the first outgoing light L3a emitted from the second region A2 of the liquid crystal element 40. In other words, the second illumination range H2 shown in FIG. 6 is the same as the second partial range HB. It goes without saying that the brightness of the second partial range HB is equal to the brightness of the second illumination range H2.

[0076] In this way, the first illumination range H1 and the second illumination range H2 are switched depending on whether or not a potential is applied to the element group 50 and the third electrode 60. Therefore, the light control device 30 can easily switch the illumination range.

[0077] Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible within the scope of the present disclosure. Appropriate modifications made within the scope of the present disclosure also naturally fall within the technical scope of the present disclosure.

[0078] For example, the lighting device 1 may include a reflector, instead of the first lens 20, that converts the light L1 from the light source 10 into parallel light and causes the parallel light to be incident as incident light L2 on the liquid crystal element 40. Furthermore, natural light may be incident on the light control device 30 instead of the light L1 from the light source 10.

[0079] Furthermore, it goes without saying that the shape of the first region A1 is not limited to a trapezoidal shape in a planar view, and it may be a polygonal shape such as a triangular shape or a rectangular shape. The shapes of the first region A1 and the second region A2 are determined based on the desired first illumination range H1 and second illumination range H2.

[0080] Furthermore, the first connection member 54 may electrically connect three or more first electrodes 52 in parallel, and the second connection member 55 may electrically connect three or more second electrodes 53 in parallel.

[0081] Furthermore, the liquid crystal element 40 may not include the first connecting member 54 and the second connecting member 55. In this case, the first electrodes 52 are electrically isolated from one another, and the second electrodes 53 are electrically isolated from one another.

[0082] The electrical resistance film 51 and the first electrode 52 may be electrically connected but isolated from each other. In this case, the gradient of the potential and the gradient of the phase difference shown in Fig. 4 change. The electrical resistance film 51 and the second electrode 53 may be electrically connected but isolated from each other.

[0083] 7 is a diagram illustrating a third illumination range H3 illuminated by the lighting device 1 according to the modified embodiment of the present disclosure. The control circuit sets the range illuminated by the lighting device 1 to one of the first illumination range H1, the second illumination range H2, and the third illumination range H3.

[0084] In the liquid crystal element 40, the first electrode 52 and the second electrode 53 are arranged as in the above embodiment, so that the plurality of element sets 50 includes at least two element sets 50 that are electrically isolated from each other. In this modification, the control circuit selects an element set 50 to which a potential is applied from among the plurality of element sets 50, thereby setting the range illuminated by the lighting device 1 to a third lighting range H3.

[0085] 2, a potential is applied to one of the plurality of sets of first electrodes C1a among the plurality of sets of first electrodes C1. Furthermore, a potential is applied to one of the plurality of sets of second electrodes C2a among the plurality of sets of second electrodes C2. In this case, a potential is applied to the element set 50 in the third region A3 that overlaps in plan view with the electrical resistance film 51 corresponding to one of the sets of first electrodes C1a and one of the sets of second electrodes C2a among the plurality of element sets 50 in the first region A1. The third region A3 is a part of the first region A1.

[0086] Therefore, the outgoing light L3 emitted from the third region A3 of the liquid crystal element 40 corresponds to the second outgoing light L3b along the second direction D2. Therefore, the outgoing light L3 emitted from the third region A3 of the liquid crystal element 40 is emitted from the reflecting surface 72 of the second lens 70 along the fourth direction D4 and is not emitted to the outside of the vehicle.

[0087] 7 corresponds to the third area A3. The third partial area HC is an area in which oncoming vehicles are not illuminated.

[0088] On the other hand, the outgoing light L3 emitted from the second region A2 and the region other than the third region A3 in the first region A1 of the liquid crystal element 40 corresponds to the first outgoing light L3a along the first direction D1. Therefore, the outgoing light L3 emitted from the second region A2 and the region other than the third region A3 in the first region A1 of the liquid crystal element 40 is emitted as light L4 from the second outgoing surface 73 of the second lens 70 to the outside of the vehicle.

[0089] Therefore, the third illumination range H3 corresponds to the range combining the first partial range HA and the second partial range HB, excluding the third partial range HC.

[0090] Furthermore, by the control circuit selecting the element set 50 to which the potential is applied from among the multiple element sets 50, the third illumination range H3 is set to a range that does not illuminate oncoming vehicles and is wider than the second illumination range H2.

[0091] Furthermore, other effects and advantages brought about by the aspects described in the above embodiments that are clear from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present disclosure.

[0092] REFERENCE SIGNS LIST 1 Illumination device 10 Light source 20 First lens 30 Light control device 40 Liquid crystal element 41 First substrate 42 Second substrate 43 Liquid crystal layer 50 Element set 51 Electrically resistive film 52 First electrode 53 Second electrode 60 Third electrode 70 Second lens (lens) 71 Second incident surface 72 Reflecting surface (second surface) 73 Second exit surface (first surface) A1 First region A2 Second region D1 First direction D2 Second direction D3 Third direction D4 Fourth direction E1 First potential E2 Second potential L2 Incident light L3 Exit light

Claims

a first substrate, a second substrate, and a liquid crystal layer between the first substrate and the second substrate, the liquid crystal element having a first surface on which light emitted from the liquid crystal element is incident and which diffuses and emits the emitted light, the liquid crystal element having a first region in which a plurality of element groups, each including an electrically resistive film and a first electrode and a second electrode which are electrically connected to the electrically resistive film in a mutually opposing state, are disposed on the first substrate, and a third electrode which overlaps with the electrically resistive film in a planar view is disposed on the second substrate; and a second region in which the electrically resistive film is not disposed, the first region of the liquid crystal element emits the emitted light along the first direction when no potential is applied to the element group and the third electrode, and emits the emitted light along a second direction different from the first direction when a potential is applied to the element group and the third electrode, the second region of the liquid crystal element emits the emitted light along the first direction, the lens further has a second surface that totally reflects the outgoing light incident along the first direction along a third direction toward the first surface, and refracts the outgoing light incident along the second direction along a fourth direction away from the first surface.

2. The light control device according to claim 1, wherein the plurality of element sets includes at least two element sets that are electrically isolated from each other.

3. The light control device according to claim 1, wherein the liquid crystal layer overlaps the first region and separates the second region in a plan view.

4. The light control device according to claim 1, wherein a first potential is applied to the first electrode, and a second potential higher than the first potential is applied to the second electrode.

5. A lighting device comprising: a light control device according to claim 1; and a light source that emits light incident on the light control device.

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