Light control system, light control device, and lighting device

Abstract

Each of a plurality of light control devices 31 included in a light control system 30 includes: a liquid crystal element 40 that transmits incident light L2 incident along a first direction D1 and emits the transmitted light; and a diffusion lens 70 on which an emission light L3 of the liquid crystal element 40 is incident. In each of a plurality of individual areas PA of the liquid crystal element 40, the emission light L3 is emitted along the first direction D1 when a potential is not applied, and the emission light L3 is emitted along a second direction D2, which is different from the first direction D1, when the potential is applied. The diffusion lens 70 has a reflection surface 72 where the emission light L3 incident along the first direction D1 undergoes total reflection along a third direction D3 toward a second emission surface 73 and where the emission light L3 incident along the second direction D2 is refracted and emitted along a fourth direction D4 away from the second emission surface 73. The potential is selectively applied to each of the individual areas PA of the liquid crystal element 40.

Description

Light control system, light control device, and lighting device

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

[0002] Japanese Patent Application Laid-Open Nos. 2003-129999 and 2003-129999 disclose, as examples of light control systems, vehicle headlights and vehicle headlight devices that can control an illumination area (illumination range).

[0003] JP 2019-50134 A JP 2013-54849 A

[0004] In the light control systems of Patent Documents 1 and 2, the illumination range may deviate from the desired range depending on the state of installation on the vehicle, etc. Therefore, there is a demand for a way to easily adjust the illumination range.

[0005] The present disclosure aims to provide a light control system, a light control device, and a lighting device that can easily adjust the illumination range.

[0006] The light control system of the present disclosure includes a first light control device and a second light control device, each of which has a first substrate, a second substrate, and a liquid crystal layer between the first substrate and the second substrate, and which includes a liquid crystal element that transmits incident light incident along a first direction and emits the incident light from an emission surface, and a lens having a first surface onto which the emitted light of the liquid crystal element is incident and which diffuses the emitted light and emits the diffused light, and the liquid crystal element includes a plurality of individual regions in which a plurality of element groups including an electrically resistive film and a first electrode and a second electrode electrically connected to the electrically resistive film in a mutually opposing state are arranged on the first substrate, and a third electrode that overlaps the electrically resistive film in a planar view is arranged on the second substrate. a potential is selectively applied to the plurality of element groups and the third electrode for each individual region, the plurality of individual regions are arranged in a matrix in a planar view of the emission surface, and when no potential is applied to the plurality of element groups and the third electrode, the emitted light is emitted along the first direction, and when a potential is applied to the plurality of element groups and the third electrode, the emitted light is emitted along a second direction different from 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, and emits the emitted light.

[0007] Further, a light control device according to the present disclosure includes 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 that receives the light emitted from the liquid crystal element and diffuses the light to emit it from an emission region of an emission surface, the liquid crystal element including 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 that receives the light emitted from the liquid crystal element and diffuses the light to emit it, the liquid crystal element including a plurality of element groups arranged on the first substrate, the element groups including an electrically resistive film and a first electrode and a second electrode that are electrically connected to the electrically resistive film while facing each other, and a plurality of individual regions in which a third electrode that overlaps the electrically resistive film in a planar view is arranged on the second substrate, the liquid crystal element further including a plurality of signal lines arranged on the first substrate and parallel to each other in a planar view, a plurality of gate lines arranged on the first substrate and parallel to each other in a planar view and intersecting the signal lines, and a plurality of switching elements arranged in each of the individual regions, and a potential is selectively applied to the plurality of element groups and the third electrode for each of the individual regions. the individual region is an area surrounded by two of the signal lines adjacent to each other in a planar view and two of the gate lines adjacent to each other, and emits the emitted light along the first direction when no potential is applied to the plurality of element groups 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 plurality of element groups and the third electrode, 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, and emits the emitted light, and the plurality of switching elements each include a drain electrode electrically connected to the second electrode included in a plurality of element groups that overlap one of the individual regions in a planar view, a gate electrode electrically connected to the gate line, and a source electrode electrically connected to the signal line.

[0008] Moreover, the lighting device of the present disclosure includes the above-described light control system, a first light source that emits light that is incident on the first light control device, and a second light source that emits light that is incident on the second light control device.

[0009] FIG. 1 is a diagram illustrating the configuration of an illumination device according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating the configurations of a light source, a collimating lens, and a light control device illustrated in FIG. 1. FIG. 3 is a plan view of the liquid crystal element illustrated in FIG. 2. FIG. 4 is a cross-sectional view of the liquid crystal element taken along line IV-IV illustrated in FIG. 3. FIG. 5 is a partially enlarged plan view of the first substrate illustrated in FIG. 4. FIG. 6 is a diagram illustrating the potential of the resistive film when the liquid crystal element refracts incident light, and the phase difference of incident light passing through the liquid crystal layer. FIG. 7 is a diagram illustrating a first predetermined range and a second predetermined range. FIG. 8 is a plan view of liquid crystal elements of the first and second light control devices. FIG. 9 is a plan view of a liquid crystal element of the third light control device. FIG. 10 is a cross-sectional view of a liquid crystal element included in an illumination device according to a second embodiment of the present disclosure. FIG. 11 is a partially enlarged plan view of the first substrate illustrated in FIG. 10. FIG. 12 is a diagram illustrating the circuit configuration of the liquid crystal element illustrated in FIG. 10.

[0010] 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.

[0011] 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.

[0012] 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 40, which will be described later. The Z direction corresponds to the thickness direction of the liquid crystal element 40. The X, Y, and Z directions are perpendicular to one another. Furthermore, in this specification, "planar view" refers to viewing the liquid crystal element 40 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.

[0013] 1 is a diagram showing the configuration of an illumination device 1 according to an embodiment of the present disclosure. The illumination device 1 is, for example, a headlight or a spotlight of a vehicle.

[0014] The lighting device 1 includes a first light source 10a, a second light source 10b, and a third light source 10c. Hereinafter, when the first light source 10a, the second light source 10b, and the third light source 10c are not distinguished from each other, they will be simply referred to as light sources 10. The lighting device 1 includes a plurality of light sources 10.

[0015] The illumination device 1 also includes a first collimating lens 20 a, a second collimating lens 20 b, and a third collimating lens 20 c. Hereinafter, when the first collimating lens 20 a, the second collimating lens 20 b, and the third collimating lens 20 c are not distinguished from one another, they will be simply referred to as collimating lenses 20. The illumination device 1 includes a plurality of collimating lenses 20.

[0016] Furthermore, the lighting device 1 includes a light control system 30. The light control system 30 includes a first light control device 31a, a second light control device 31b, and a third light control device 31c. The first light control device 31a, the second light control device 31b, and the third light control device 31c have the same configuration. Hereinafter, when the first light control device 31a, the second light control device 31b, and the third light control device 31c are described without distinguishing one from another, they will be simply referred to as light control devices 31.

[0017] In this way, the light control system 30 includes a plurality (three in this embodiment) of light control devices 31. It goes without saying that the number of light control devices 31 included in the light control system 30 is not limited to three.

[0018] The number of light sources 10 and the number of collimating lenses 20 are equal to the number of light control devices 31. In this embodiment, the number of light sources 10 and the number of collimating lenses 20 are three. The first light source 10a and the first collimating lens 20a correspond to the first light control device 31a. The second light source 10b and the second collimating lens 20b correspond to the second light control device 31b. The third light source 10c and the third collimating lens 20c correspond to the third light control device 31c.

[0019] Fig. 2 is a diagram showing the configurations of the light source 10, the collimator lens 20, and the light control device 31 shown in Fig. 1. The light control device 31 includes a liquid crystal element 40 and a diffusing lens 70 (corresponding to "lens").

[0020] The light source 10 emits light L1 that enters the light control device 31. Specifically, the light L1 from the light source 10 enters the liquid crystal element 40 via a collimator lens 20. The light source 10 is, for example, an LED (light emitting diode).

[0021] The collimator lens 20 is an optical element that collimates the traveling direction of the light L1 from the light source 10. The collimator lens 20 converts the incident light L2 that is incident on the liquid crystal element 40 into parallel light.

[0022] 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 the incident light L2 incident along the first direction D1 and emits output light L3 from a first output surface 40b (surface on the +Z side, corresponding to the "output surface").

[0023] Fig. 3 is a plan view of the liquid crystal element 40 shown in Fig. 2. Fig. 4 is a cross-sectional view of the liquid crystal element 40 taken along line IV-IV shown in Fig. 3. Fig. 5 is a partially enlarged plan view of the first substrate 41 shown in Fig. 4.

[0024] The liquid crystal element 40 has a plurality of individual areas PA. The plurality of individual areas PA are arranged in a matrix along the X and Y directions in a plan view of the first light exit surface 40b. The plurality of individual areas PA constitute an exit area SA on the first light exit surface 40b from which the emitted light L3 is emitted. In other words, the exit area SA is divided into a plurality of individual areas PA.

[0025] 4, 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.

[0026] In each of the individual areas PA, a plurality of element sets 50 and third electrodes 60 shown in FIGS. 4 and 5 are arranged.

[0027] 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.

[0028] 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.

[0029] The first electrode 52 and the second electrode 53 are electrically connected to the electrical resistance film 51 .

[0030] 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. Note that the first electrode 52 may be separated from the electrical resistance film 51.

[0031] 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. Note that the second electrode 53 may be separated from the electrical resistance film 51.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In each individual area PA, the plurality of element groups 50 are arranged along the X direction. As described above, each of the plurality of element groups 50 includes a strip-shaped electrically resistive film 51 extending along the Y direction. The plurality of element groups 50 are arranged along the X direction with two adjacent electrically resistive films 51 spaced apart from each other in the X direction. Furthermore, as described above, the plurality of element groups 50 are arranged in each of the plurality of individual areas PA arranged in a matrix along the X and Y directions. Therefore, the plurality of electrically resistive films 51 are arranged in a matrix along the X and Y directions.

[0036] 5 , the liquid crystal element 40 includes a plurality of first connection lines CL1 and a plurality of second connection lines CL2. The first connection lines CL1 and the second connection lines CL2 are made of a conductive material containing aluminum, molybdenum, etc. The plurality of first connection lines CL1 and the plurality of second connection lines CL2 are electrically connected to a control circuit that controls the lighting device 1.

[0037] The first connection lines CL1 and the second connection lines CL2 are arranged to extend along the X direction on the first substrate 41. The first connection lines CL1 and the second connection lines CL2 are spaced apart from each other and electrically insulated from each other.

[0038] One first connection line CL1 is disposed between two adjacent electrical resistance films 51 in the Y direction. The first connection line CL1 is electrically connected to a plurality of first electrodes 52 included in a plurality of individual areas PA aligned in a row along the X direction. In other words, the plurality of first electrodes 52 are electrically connected to a control circuit via the first connection line CL1.

[0039] The second connection line CL2 is arranged between two adjacent electrical resistance films 51 in the Y direction. The second connection line CL2 is electrically connected to the multiple second electrodes 53 included in one individual area PA. In other words, the multiple second electrodes 53 are electrically connected to the control circuit via the second connection line CL2. The maximum number of second connection lines CL2 arranged between two adjacent individual areas PA in the Y direction is equal to the number of multiple individual areas PA lined up in a row along the X direction.

[0040] The liquid crystal element 40 further includes a light-shielding film (not shown) disposed between two adjacent electrical resistance films 51 in the X and Y directions in plan view. The light-shielding film overlaps with the first connecting line CL1 and the second connecting line CL2 in plan view.

[0041] 4, an insulating layer 44 and a first alignment film AL1 are disposed on the first substrate 41. The plurality of element groups 50, the first connection lines CL1, and the second connection lines CL2 are disposed on the insulating layer 44 and are electrically insulated from one another. 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 44.

[0042] 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. The third electrode 60 overlaps with a plurality of electrical resistance films 51 in a planar view. The third electrode 60 is configured by being divided into a plurality of individual regions PA. The third electrode 60 is electrically connected to a control circuit via a plurality of connection lines (not shown) disposed on the second substrate 42. Similar to the first connection line CL1, one connection line is disposed so as to extend along the X direction between two electrical resistance films 51 adjacent to each other in the Y direction in a planar view. Note that, when a reference potential is applied to the first electrode 52 and the third electrode 60 as described below, the third electrode 60 may be integrally configured so as to overlap with all of the electrical resistance films 51 of the liquid crystal element 40 in a planar view, rather than being divided into a plurality of individual regions PA.

[0043] 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).

[0044] 4, the liquid crystal layer 43 is sandwiched between a first alignment film AL1 and a second alignment film AL2. The liquid crystal layer 43 overlaps with the emission area SA in a plan view.

[0045] 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 potential 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.

[0046] 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.

[0047] Next, a description will be given of the operation of refracting incident light L2 by the liquid crystal element 40. As shown in Fig. 2, incident light L2 enters the first entrance surface 40a of the liquid crystal element 40 along the first direction D1.

[0048] When no potential is applied to the plurality of element groups 50 and the third electrode 60 in the individual area PA, the liquid crystal molecules LM of the liquid crystal layer 43 remain in their initial orientation. In this case, the liquid crystal element 40 does not generate a phase difference for the incident light L2, and the incident light L2 passes through without being refracted and is emitted from the first emission surface 40b. That is, in this case, the emitted light L3 emitted from the liquid crystal element 40 is aligned along the first direction D1. Hereinafter, the emitted light L3 along the first direction D1 emitted from the liquid crystal element 40 is referred to as the first emitted light L3a.

[0049] On the other hand, when a potential is applied to the plurality of element groups 50 and the third electrode 60 in the individual area PA, the liquid crystal element 40 refracts the incident light L2 and emits it from the first emission surface 40b along a second direction D2, as described below. 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."

[0050] 6 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. The horizontal axis in Fig. 6 represents the position (coordinate) in the X direction. The symbols in parentheses are the symbols of the parts of the electrical resistance film 51 shown in Fig. 4, and the arrows corresponding to the symbols indicate the range of the parts of the electrical resistance film 51 corresponding to the symbols.

[0051] When the liquid crystal element 40 refracts the incident light L2, a first potential E1 is applied to the first electrode 52 via the first connection line CL1, and a second potential E2 higher than the first potential E1 is applied to the second electrode 53 via the second connection line CL2 by the control circuit. In addition, the first potential E1 is 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. The length of the intermediate portion 51c in the X direction 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 and the length of the intermediate portion 51c in the X direction.

[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] 6, 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. 6 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] 6, the phase difference of the incident light L2 passing through the liquid crystal layer 43 changes, causing the incident light L2 to be refracted by the liquid crystal layer 43 and to be emitted as second outgoing light L3b along the second direction D2 from the liquid crystal element 40. In this way, the liquid crystal element 40 can refract the incident light L2 with a simple configuration.

[0060] 2 receives the outgoing light L3 from the liquid crystal element 40, and diffuses the incident outgoing light L3 before outputting it. The diffusing lens 70 has a second entrance surface 71, a reflecting surface 72 (corresponding to the "second surface"), and a second exit surface 73 (corresponding to the "first surface").

[0061] 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 diffusing lens 70 are integrated.

[0062] 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.

[0063] 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 L4 as light L4. The second exit surface 73 has a spherical shape. The light L4 is light that is emitted by the light control device 31.

[0064] Next, the operation of the lighting device 1 will be described in the case where the lighting device 1 is a headlight of a vehicle.

[0065] FIG. 7 is a diagram showing a first predetermined range H1 and a second predetermined range H2. The lighting device 1 emits light L4 toward the first predetermined range H1 and the second predetermined range H2. 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-right direction 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.

[0066] The lighting device 1 emits what are called low beams and high beams. When the lighting device 1 emits light L4 only toward the first predetermined range H1 out of the first predetermined range H1 and the second predetermined range H2, the light L4 corresponds to a low beam. When the lighting device 1 emits light L4 toward both the first predetermined range H1 and the second predetermined range H2, the light L4 corresponds to a high beam.

[0067] The first light control device 31a and the second light control device 31b emit light L4 toward a first predetermined range H1. That is, the light L4 emitted by the first light control device 31a and the light L4 emitted by the second light control device 31b overlap in the first predetermined range H1. In other words, the range illuminated by the first light control device 31a and the range illuminated by the second light control device 31b overlap each other. Furthermore, the third light control device 31c emits light L4 toward a second predetermined range H2.

[0068] That is, when the lighting device 1 emits a low beam, two of the three light control devices 31, the first light control device 31a and the second light control device 31b, emit light L4. When the lighting device 1 emits a high beam, all of the three light control devices 31 emit light L4.

[0069] Fig. 8 is a plan view of the liquid crystal element 40 of the first light control device 31a and the second light control device 31b. The first emission range SR1 shown in Fig. 8 corresponds to the first predetermined range H1. Fig. 9 is a plan view of the liquid crystal element 40 of the third light control device 31c. The second emission range SR2 shown in Fig. 9 corresponds to the second predetermined range H2.

[0070] When the control circuit does not allow the lighting device 1 to emit light L4, it does not allow the light source 10 to emit light L1, and does not apply a potential to any of the element groups 50 and third electrodes 60 in the three light control devices 31.

[0071] On the other hand, when the control circuit controls the lighting device 1 to emit a low beam, it controls the first light source 10 a and the second light source 10 b to emit light L1, and controls the third light source 10 c not to emit light L1. In this case, the control circuit does not apply a potential to any of the element sets 50 and the third electrode 60 in the third light control device 31 c.

[0072] Furthermore, in this case, the control circuit does not apply a potential to the plurality of element groups 50 and the third electrodes 60 corresponding to the individual areas PA within the first emission range SR1 in the first light control device 31 a and the second light control device 31 b. Therefore, the first emission light L3 a emitted from the plurality of individual areas PA within the first emission range SR1 in the first light control device 31 a and the second light control device 31 b is emitted as light L4 from the second emission surface 73 of the diffusing lens 70 toward the first predetermined range H1.

[0073] In this case, the control circuit applies a potential to the plurality of element groups 50 and the third electrodes 60 corresponding to the plurality of individual areas PA outside the first emission range SR1 in the first light control device 31 a and the second light control device 31 b. Therefore, the second emission light L3 b emitted from the plurality of individual areas PA outside the first emission range SR1 in the first light control device 31 a and the second light control device 31 b is emitted from the reflecting surface 72 of the diffusing lens 70 and is not emitted outside the vehicle.

[0074] In this way, a potential is selectively applied for each individual area PA to the plurality of element groups 50 and the third electrodes 60. When emitting a low beam, the lighting device 1 applies a potential to the plurality of element groups 50 and the third electrodes 60 corresponding to the plurality of individual areas PA outside the first emission range SR1 in the first light control device 31a and the second light control device 31b, thereby emitting light L4 toward the first predetermined range H1.

[0075] Furthermore, when the control circuit causes the lighting device 1 to emit a high beam, it causes the three light sources 10 to emit light L1. In this case, similar to the case when the lighting device 1 emits a low beam as described above, the control circuit applies a potential to the plurality of element groups 50 and the third electrodes 60 in the first light control device 31a and the second light control device 31b that correspond to the individual areas PA outside the first emission range SR1, thereby causing the first light control device 31a and the second light control device 31b to emit light L4 toward the first predetermined range H1.

[0076] Furthermore, when the control circuit causes the lighting device 1 to emit a high beam, the control circuit does not apply a potential to the plurality of element groups 50 and the third electrode 60 corresponding to the plurality of individual areas PA within the second emission range SR2 in the third light control device 31c. Therefore, the first emission light L3a emitted from the plurality of individual areas PA within the second emission range SR2 in the third light control device 31c is emitted as light L4 from the second emission surface 73 of the diffusion lens 70 toward the second predetermined range H2.

[0077] In this case, the control circuit applies a potential to the plurality of element groups 50 and the third electrode 60 corresponding to the plurality of individual areas PA outside the second emission range SR2 in the third light control device 31c. Therefore, the second emission light L3b emitted from the plurality of individual areas PA outside the second emission range SR2 in the third light control device 31c is emitted from the reflective surface 72 of the diffusing lens 70 and is not emitted outside the vehicle.

[0078] In this way, when emitting a high beam, the lighting device 1 emits light L4 toward the first predetermined range H1 by applying a potential to the plurality of element sets 50 and the third electrodes 60 corresponding to the plurality of individual areas PA outside the first emission range SR1 in the first light control device 31a and the second light control device 31b. Furthermore, when emitting a high beam, the lighting device 1 emits light L4 toward the second predetermined range H2 by applying a potential to the plurality of element sets 50 and the third electrodes 60 corresponding to the plurality of individual areas PA outside the second emission range SR2 in the third light control device 31c.

[0079] Furthermore, in the lighting device 1 configured as described above, depending on the state of installation on the vehicle, the ranges actually illuminated by the first light control device 31a and the second light control device 31b may deviate from the first predetermined range H1. Similarly, the range actually illuminated by the third light control device 31c may deviate from the second predetermined range H2.

[0080] For example, as shown in Figure 7, if the illumination range Hr, which is the range actually illuminated by the third light control device 31c, deviates from the second predetermined range H2, it is necessary to adjust the illumination range Hr so that it coincides with the second predetermined range H2.

[0081] When adjusting the illumination range Hr of the third light control device 31c, the second emission range SR2 shown in FIG. 9 is adjusted. Specifically, the second emission range SR2 is moved so that the illumination range Hr shown in FIG. 7 coincides with the second predetermined range H2. In FIG. 9, the second emission range SR2 after movement is indicated by a dashed line. In this manner, by moving the second emission range SR2, the individual area PA to which a potential is applied to the plurality of element groups 50 and the third electrode 60 is adjusted (changed). As a result, the illumination range Hr moves, and the illumination range Hr coincides with the second predetermined range H2.

[0082] Note that the first emission range SR1 is also adjusted when the illumination ranges actually illuminated by the first light control device 31 a and the second light control device 31 b deviate from the first predetermined range H1. In this way, the illumination range of the illumination device 1 can be easily adjusted without adjusting the mounting state of the illumination device 1 on the vehicle.

[0083] Second Embodiment Next, a lighting device 1 according to a second embodiment of the present disclosure will be described, mainly focusing on the differences from the lighting device 1 of the first embodiment described above.

[0084] Fig. 10 is a cross-sectional view of a liquid crystal element 40 included in an illumination device 1 according to a second embodiment of the present disclosure. Fig. 11 is a partially enlarged plan view of a first substrate 41 shown in Fig. 10. Fig. 12 is a diagram showing a circuit configuration of the liquid crystal element 40 shown in Fig. 10.

[0085] In the second embodiment, the electrical resistance film 151 of the element group 150 is disposed on a second insulating layer 145 that is laminated on the insulating layer 44. The second electrode 153 is disposed on the second insulating layer 145 at a distance from the electrical resistance film 151. The first electrode 152 is disposed on the insulating layer 44 at a distance from the electrical resistance film 151.

[0086] In the liquid crystal element 40 of the second embodiment, the first connection line CL1 is electrically connected to the plurality of first electrodes 152 included in the plurality of individual areas PA arranged in a row along the Y direction, as in the first embodiment. The first connection line CL1 is disposed on the insulating layer 44.

[0087] Furthermore, the liquid crystal element 40 does not include a second connection line CL2. The liquid crystal element 40 includes, in each individual area PA, two third connection lines CL3 that are electrically connected in parallel to the plurality of second electrodes 153 included in one individual area PA. The two third connection lines CL3 are arranged at both ends of the plurality of second electrodes 153. The two third connection lines CL3 are arranged on the second insulating layer 145.

[0088] The liquid crystal element 40 further includes a plurality of signal lines SL, a plurality of gate lines GL, and a plurality of switching elements 146 arranged on the first substrate 41 .

[0089] The signal lines SL are parallel to one another in a plan view of the liquid crystal element 40. Specifically, the signal lines SL extend along the X direction and are arranged on the insulating layer 44 so as to be aligned along the Y direction.

[0090] The multiple gate lines GL are parallel to each other and intersect with the signal lines SL in a plan view of the liquid crystal element 40. Specifically, the multiple gate lines GL extend along the Y direction and are arranged in the second insulating layer 145 so as to be aligned along the X direction. In a plan view of the liquid crystal element 40, an area surrounded by two adjacent signal lines SL and two adjacent gate lines GL corresponds to one individual area PA.

[0091] One switching element 146 is arranged in each individual area PA. The switching element 146 is a transistor. In each of the individual areas PA, a gate electrode 146 a of the switching element 146 is electrically connected to a gate line GL, and a source electrode 146 b of the switching element 146 is electrically connected to a signal line SL.

[0092] Furthermore, the drain electrode 146c of the switching element 146 is electrically connected to one third connection line CL3. That is, the drain electrode 146c of the switching element 146 is electrically connected to the second electrodes 153 included in the element groups 50 that overlap one individual area PA in plan view.

[0093] In the second embodiment, the number of signal lines SL and the number of first connection lines CL1 arranged between two adjacent electrical resistance films 151 in the Y direction in plan view are each one. On the other hand, in the first embodiment described above, the maximum number of second connection lines CL2 arranged between two adjacent electrical resistance films 151 in the Y direction in plan view is equal to the number of multiple individual areas PA arranged in a row along the X direction. Therefore, the total number of signal lines SL and first connection lines CL1 in the second embodiment between two adjacent electrical resistance films 151 in the Y direction in plan view is less than the maximum number of second connection lines CL2 in the first embodiment described above.

[0094] Therefore, in the liquid crystal element 40 of the second embodiment, the distance between two adjacent electrical resistance films 151 in the Y direction in plan view can be made smaller than in the liquid crystal element 40 of the first embodiment. Therefore, the proportion of the area in the emission area SA that emits the emitted light L3 can be increased. In other words, the light L1 from the light source 10 can be used efficiently. Furthermore, the light L4 emitted by the lighting device 1 can be made more precise.

[0095] In the second embodiment, when the lighting device 1 emits low beams and high beams, similarly to the lighting device 1 of the first embodiment described above, the control circuit applies a potential to the plurality of element groups 50 and the third electrodes 60 in the first light control device 31a and the second light control device 31b that correspond to the individual areas PA outside the first emission range SR1. Specifically, the control circuit scans the plurality of gate lines GL to turn on the switching elements 146 that correspond to the individual areas PA outside the first emission range SR1. As a result, similarly to the lighting device 1 of the first embodiment described above, the first light control device 31a and the second light control device 31b emit light L4 toward the first predetermined range H1.

[0096] Furthermore, when the illumination ranges actually illuminated by the first light control device 31 a and the second light control device 31 b are adjusted, the first emission range SR1 is adjusted (moved) in the emission area SA in the same manner as in the first embodiment. Specifically, the individual area PA in which the switching element 146 is turned on in the first light control device 31 a and the second light control device 31 b is adjusted (changed).

[0097] Furthermore, when the lighting device 1 emits a high beam, similarly to the lighting device 1 of the first embodiment described above, the control circuit applies a potential to the plurality of element groups 50 and the third electrodes 60 in the third light control device 31c that correspond to the individual areas PA outside the second emission range SR2. Specifically, the control circuit scans the plurality of gate lines GL to turn on the switching elements 146 that correspond to the individual areas PA outside the second emission range SR2. As a result, similarly to the first embodiment described above, the third light control device 31c emits light L4 toward the second predetermined range H2.

[0098] Furthermore, when the illumination range Hr actually illuminated by the third light control device 31c is adjusted, the second emission range SR2 is adjusted (moved) in the emission area SA in the same manner as in the first embodiment. Specifically, the individual area PA in which the switching element 146 is turned on in the third light control device 31c is adjusted (changed).

[0099] 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.

[0100] For example, the number of light control devices 31 included in the lighting device 1 is not limited to three, and may be two or more.

[0101] It goes without saying that the illumination range of the light control device 31 is not limited to the above range. For example, the first light control device 31a may emit light L4 toward the second predetermined range H2, and the second light control device 31b may emit light L4 toward the second predetermined range H2. Alternatively, the third light control device 31c may emit light L4 toward the first predetermined range H1. Alternatively, the three light control devices 31 may emit light L4 toward different ranges or toward the same range.

[0102] Furthermore, the size and shape of the illumination range of the light control device 31 may be adjusted by adjusting the size and shape of the first emission range SR1 and the second emission range SR2.

[0103] Furthermore, the lighting device 1 may include a reflector, instead of the collimator 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 31 instead of the light L1 from the light source 10.

[0104] The liquid crystal elements 40 included in the three light control devices 31 may be integrated. Furthermore, when a heat dissipation member is provided for the three light sources 10, the three light sources 10 may be provided on one heat dissipation member.

[0105] 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.

[0106] 1 Lighting device 10 Light source 20 Collimating lens 30 Light control system 31 Light control device 31a First light control device 31b Second light control device 40 Liquid crystal element 40a First incident surface 40b First exit surface (exit surface) 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 Diffusion lens (lens) 71 Second incident surface 72 Reflection surface (second surface) 73 Second exit surface (first surface) 146 Switching element 146a Gate electrode 146b Source electrode 146c Drain electrode D1 First direction D2 Second direction D3 Third direction D4 Fourth direction E1 First potential E2 Second potential GL Gate line L1 Light L2 Incident light L3 Output light PA Individual area SL Signal line

Claims

1. A first light control device and a second light control device, each of which comprises a liquid crystal element having a first substrate, a second substrate, and a liquid crystal layer between the first and second substrates, which transmits incident light incident along a first direction and emits it from an emission surface, and a lens having a first surface onto which the emitted light of the liquid crystal element is incident and which diffuses the emitted light and emits it, wherein the liquid crystal element comprises a plurality of individual regions on the first substrate, each of which comprises a plurality of element groups including an electrically resistive film and a first electrode and a second electrode electrically connected to the electrically resistive film in a mutually opposing state, and a third electrode on the second substrate which overlaps the electrically resistive film in a planar view, and a potential is selectively applied to the plurality of element groups and the third electrode for each of the individual regions, and the plurality of individual regions are arranged in a matrix in a planar view of the emission surface, and an optical control system, wherein the outgoing light is emitted along the first direction when no potential is applied to the plurality of element groups and the third electrode, and the outgoing light is emitted along a second direction different from the first direction when a potential is applied to the plurality of element groups and the third electrode, and 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, and emits the outgoing light.

2. The light control system according to claim 1, wherein the range illuminated by the first light control device and the range illuminated by the second light control device overlap each other.

3. The light control system 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.

4. The optical control system of claim 1, wherein the liquid crystal element further comprises: a plurality of signal lines arranged on the first substrate and parallel to each other in a planar view; a plurality of gate lines arranged on the first substrate and parallel to each other in a planar view and intersecting the signal lines; and a plurality of switching elements arranged in each of the individual regions, wherein the individual region is an area surrounded by two of the signal lines adjacent to each other in a planar view and two of the gate lines adjacent to each other, and each of the plurality of switching elements comprises: a drain electrode electrically connected to a plurality of second electrodes included in a plurality of the element groups overlapping one of the individual regions in a planar view; a gate electrode electrically connected to the gate line; and a source electrode electrically connected to the signal line.

5. A liquid crystal element having a first substrate, a second substrate, and a liquid crystal layer between the first and second substrates, which transmits incident light incident along a first direction and emits the light from an emission region of an emission surface; and a lens having a first surface onto which the emitted light of the liquid crystal element is incident and which diffuses the emitted light and emits it, wherein the liquid crystal element comprises: a plurality of element groups, each including an electrically resistive film and a first electrode and a second electrode electrically connected to the electrically resistive film while facing each other, arranged on the first substrate; and a plurality of individual regions, each including a third electrode overlapping the electrically resistive film in a planar view, arranged on the second substrate; a plurality of signal lines, each parallel to each other in a planar view, arranged on the first substrate; a plurality of gate lines, each parallel to each other in a planar view and intersecting the signal lines, arranged on the first substrate; and a plurality of switching elements arranged in each of the individual regions, wherein a potential is selectively applied to the plurality of element groups and the third electrode for each of the individual regions, and the individual regions are 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, and emits the emitted light; and the plurality of switching elements each include: a drain electrode electrically connected to the second electrode included in a plurality of element sets that overlap with one of the individual regions in a planar view; a gate electrode electrically connected to the gate line; and a source electrode electrically connected to the signal line.

6. A lighting device comprising: the light control system according to claim 1; a first light source that emits light incident on the first light control device; and a second light source that emits light that is incident on the second light control device.

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