Liquid crystal element

Abstract

To provide a liquid crystal element capable of easily adjusting the emission direction of light.SOLUTION: A liquid crystal element 1 comprises: a first substrate 10 and a second substrate 20; a plurality of first electrode sets 40 disposed on the first substrate 10 and each including a first electrode 41 and a second electrode 42; a plurality of second electrode sets 60 disposed on the second substrate 20 and each including a third electrode 61 and a fourth electrode 62; a liquid crystal layer 30 disposed between the first substrate 10 and the second substrate 20; and a plurality of light-shielding films 70 that interrupt light transmission. The first electrode 41 included in one first electrode set 40 of the plurality of first electrode sets 40 overlaps the third electrode 61 included in one second electrode set 60 of the plurality of second electrode sets 60 in plan view. The second electrode 42 included in the one first electrode set 40 overlaps the fourth electrode 62 included in the one second electrode set 60. The light-shielding film 70, in plan view, overlaps a gap G between two first electrode sets 40 that are adjacent to each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a liquid crystal device. [Background technology]

[0002] Patent Document 1 discloses a headlight with controllable light distribution. The headlight in Patent Document 1 reflects light from a light source using a mirror, and then focuses the reflected light using a lens to irradiate it ahead of the vehicle. The direction of the light irradiation can be adjusted by adjusting the angle of the mirror.

[0003] Patent Document 2 discloses an illumination device including a lamp unit including a light source and an arm connected to the lamp unit. The arm includes a first arm and a second arm connected to be rotatable relative to each other. The lamp unit and the second arm are connected to be rotatable relative to each other. The angle between the first arm and the second arm and the angle between the lamp unit and the second arm are adjusted to adjust the direction in which light from the light source is emitted. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-174551 [Patent Document 2] Japanese Patent Publication No. 2023-63255 Summary of the Invention [Problem to be solved by the invention]

[0005] In devices capable of adjusting the direction of light emission, such as those disclosed in Patent Documents 1 and 2, the adjustment of the direction of light emission is performed by operating a movable part in a mechanism including multiple mechanical parts. There is a demand for such devices with a simple configuration.

[0006] An object of the present disclosure is to provide a liquid crystal element that can easily adjust the light emission direction. [Means for solving the problem]

[0007] A liquid crystal element according to the present disclosure includes a first substrate and a second substrate facing each other, a plurality of first electrode sets arranged on the first substrate and including a first electrode and a second electrode, a plurality of second electrode sets arranged on the second substrate and including a third electrode and a fourth electrode, a liquid crystal layer between the first substrate and the second substrate, and a plurality of light-shielding films for blocking light transmission, wherein the first electrode and the second electrode in each of the plurality of first electrode sets extend along a first direction and face each other in a second direction perpendicular to the first direction, and the plurality of light-shielding films The first electrode sets and the plurality of second electrode sets are each aligned along the second direction, the first electrode included in one of the plurality of first electrode sets overlaps, in a planar view, the third electrode included in one of the plurality of second electrode sets, the second electrode included in one of the first electrode sets overlaps with the fourth electrode included in one of the second electrode sets, and the light-shielding film overlaps, in a planar view, with a gap between two first electrode sets that are adjacent to each other in the second direction among the plurality of first electrode sets. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a conceptual diagram of a liquid crystal element according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of a liquid crystal element according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view of the liquid crystal element taken along line III-III shown in FIG. [Figure 4] FIG. 4 is a plan view showing the arrangement of the first electrode group. [Figure 5] FIG. 5 is a plan view showing the arrangement of the second electrode group. [Figure 6] FIG. 6 is a diagram showing the degree of tilt of liquid crystal molecules when the liquid crystal element refracts emitted light along the fourth direction. [Figure 7] FIG. 7 is a diagram showing the phase difference of emitted light passing through the liquid crystal layer of the liquid crystal element shown in FIG. [Figure 8]FIG. 8 is a cross-sectional view of a liquid crystal element of a comparative example. [Figure 9] FIG. 9 is a diagram showing the degree of tilt of liquid crystal molecules when the liquid crystal element of the comparative example refracts emitted light so as to be along the fourth direction. DETAILED DESCRIPTION OF THE INVENTION

[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 first direction D1 and the second direction D2 shown in the drawings correspond to directions parallel to the plate surfaces of substrates included in the liquid crystal element 1, which will be described later. The first direction D1 and the second direction D2 correspond to the sides of the liquid crystal element 1. In the first direction D1, the side indicated by the arrow is the +D1 side, and the side opposite the +D1 side is the -D1 side. In the second direction D2, the side indicated by the arrow is the +D2 side, and the side opposite the +D2 side is the -D2 side.

[0012] The third direction D3 corresponds to the thickness direction of the liquid crystal element 1. In the third direction D3, the side indicated by the arrow is the +D3 side, and the side opposite to the +D3 side is the -D3 side. The +D3 side of the third direction D3 corresponds to the front side of the liquid crystal element 1, and the -D3 side of the third direction D3 corresponds to the rear side of the liquid crystal element 1. In this specification, "planar view" means viewing the liquid crystal element 1 along the third direction D3. Note that the first direction D1, the second direction D2, and the third direction D3 are merely examples, and the present disclosure is not limited to these directions.

[0013] 1 is a conceptual diagram of a liquid crystal element 1 according to an embodiment of the present disclosure. The liquid crystal element 1 is a refractive plate that refracts light. Light L emitted from a light source S is incident on the liquid crystal element 1. The light source S is, for example, a lighting device such as a vehicle headlight or spotlight.

[0014] When no voltage is applied, the liquid crystal element 1 transmits the emitted light L without changing the direction in which the emitted light L travels (emission direction), as indicated by the solid arrow. On the other hand, when a voltage is applied, the liquid crystal element 1 refracts the emitted light L so that it follows one of the two directions indicated by the dashed arrow (details will be described later).

[0015] Fig. 2 is a plan view of a liquid crystal element 1 according to an embodiment of the present disclosure. Fig. 3 is a cross-sectional view of the liquid crystal element 1 taken along line III-III shown in Fig. 2. The cross-sectional view of the liquid crystal element 1 shown in Fig. 3 shows the cross-sectional shape of the liquid crystal element 1 cut along a plane perpendicular to the first direction D1.

[0016] The liquid crystal element 1 includes a first substrate 10, a second substrate 20, and a liquid crystal layer 30.

[0017] The first substrate 10 and the second substrate 20 face each other. The first substrate 10 and the second substrate 20 are light-transmitting. The first substrate 10 and the second substrate 20 are, for example, glass substrates, resin substrates, or resin films.

[0018] A plurality of first electrode groups 40, a first insulating layer IL1, and a first alignment film AL1 are arranged on the first substrate 10. The first electrode groups 40 include a first electrode 41 and a second electrode .

[0019] 4 is a plan view showing the arrangement of the first electrode groups 40. The multiple first electrode groups 40 are arranged in a matrix along the first direction D1 and the second direction D2.

[0020] The first electrode 41 and the second electrode 42 each extend along a first direction D1. In each of the multiple first electrode groups 40, the first electrode 41 and the second electrode 42 face each other in the second direction D2. In this embodiment, in each of the multiple first electrode groups 40, the first electrode 41 is located on the −D2 side of the second electrode 42. Note that the first electrode 41 may also be located on the +D2 side of the second electrode 42.

[0021] By arranging the multiple first electrode groups 40 as described above, the multiple first electrodes 41 are arranged in a row along the first direction D1, the multiple second electrodes 42 are arranged in a row along the first direction D1, and the multiple first electrodes 41 and the multiple second electrodes 42 are arranged alternately along the second direction D2.

[0022] 3, the length in the second direction D2 between the first electrode 41 and the second electrode 42 included in one first electrode group 40 is defined as a first length H1. Furthermore, the length between two first electrode groups 40 adjacent to each other in the second direction D2 among the multiple first electrode groups 40 is defined as a second length H2. Specifically, the second length H2 is the length in the second direction D2 between the first electrode 41 and the second electrode 42 facing each other in the second direction D2 in two first electrode groups 40 adjacent to each other in the second direction D2. The first length H1 is longer than the second length H2.

[0023] As shown in FIG. 4, the liquid crystal element 1 further includes a plurality of first stem electrodes 51 and a plurality of second stem electrodes 52 arranged on the first substrate 10.

[0024] The first trunk electrode 51 extends along the second direction D2. The first trunk electrode 51 is located between two second electrodes 42 adjacent to each other in the first direction D1. The first trunk electrode 51 is spaced apart from the second electrodes 42 in a plan view. The multiple first trunk electrodes 51 are aligned along the first direction D1.

[0025] The first stem electrode 51 is electrically connected to the plurality of first electrodes 41. The first stem electrode 51 is integral with the plurality of first electrodes 41. The plurality of first electrodes 41 are electrically connected to the first stem electrode 51 so as to protrude from the first stem electrode 51 on both sides in the first direction D1.

[0026] The second stem electrode 52 extends along the second direction D2. The second stem electrode 52 is located between two adjacent first electrodes 41 in the first direction D1. The second stem electrode 52 is spaced apart from the first electrodes 41 in a plan view. The multiple second stem electrodes 52 are arranged along the first direction D1. The first stem electrodes 51 and the second stem electrodes 52 are arranged alternately in the first direction D1.

[0027] The second stem electrode 52 is electrically connected to the plurality of second electrodes 42. The second stem electrode 52 is integral with the plurality of second electrodes 42. The plurality of second electrodes 42 are electrically connected to the second stem electrode 52 so as to protrude from the second stem electrode 52 on both sides in the first direction D1.

[0028] The materials of the first electrode 41, the second electrode 42, the first stem electrode 51, and the second stem electrode 52 are conductive materials such as molybdenum tungsten alloy (MoW) and TAT (Ti / Al / Ti), which is a laminate of titanium (Ti) and aluminum (Al).

[0029] The first stem electrode 51 and the second stem electrode 52 are electrically connected to a control circuit (not shown). The control circuit applies a voltage to the first electrode 41 via the first stem electrode 51. The control circuit applies a voltage to the second electrode 42 via the second stem electrode 52.

[0030] 3 electrically insulates the first trunk electrode 51 from the second trunk electrode 52. The first insulating layer IL1 also electrically insulates the first electrode 41 from the second electrode 42.

[0031] The first alignment film AL1 is disposed on the front side of the first electrode 41 and the second electrode 42. The first alignment film AL1 is disposed in a state spaced apart from the first electrode 41 and the second electrode 42. The first alignment film AL1 may be in contact with the first electrode 41 and the second electrode 42.

[0032] A plurality of second electrode sets 60, a second insulating layer IL2, a plurality of light-shielding films 70, and a second alignment film AL2 are arranged on the second substrate 20. The second electrode sets 60 include a third electrode 61 and a fourth electrode 62.

[0033] 5 is a plan view showing the arrangement of the second electrode groups 60. The multiple second electrode groups 60 are arranged in a matrix along the first direction D1 and the second direction D2. The second electrode groups 60 face the first electrode groups 40 in the third direction D3.

[0034] The third electrode 61 and the fourth electrode 62 each extend along the first direction D1. In each of the second electrode groups 60, the third electrode 61 and the fourth electrode 62 face each other in the second direction D2. In this embodiment, in each of the second electrode groups 60, the third electrode 61 is located on the -D2 side of the fourth electrode 62.

[0035] By arranging the plurality of second electrode sets 60 as described above, the plurality of third electrodes 61 are arranged in a row along the first direction D1, the plurality of fourth electrodes 62 are arranged along the first direction D1, and the plurality of third electrodes 61 and the plurality of fourth electrodes 62 are arranged alternately along the second direction D2. Furthermore, the plurality of first electrode sets 40 and the plurality of second electrode sets 60 overlap with a refraction region RA (see FIG. 2) that refracts the emitted light L in a planar view.

[0036] As shown in FIG. 3 , the third electrode 61 overlaps the first electrode 41 in a planar view. Furthermore, the fourth electrode 62 overlaps the second electrode 42 in a planar view. Specifically, the first electrode 41 included in one of the multiple first electrode groups 40 overlaps the third electrode 61 included in one of the multiple second electrode groups 60 in a planar view, and the second electrode 42 included in that one first electrode group 40 overlaps the fourth electrode 62 included in that one second electrode group 60. Note that the third electrode 61 may overlap a portion of the first electrode 41 in a planar view. Furthermore, the fourth electrode 62 may overlap a portion of the second electrode 42 in a planar view.

[0037] As shown in FIG. 5, the liquid crystal element 1 further includes a plurality of third stem electrodes 81 and a plurality of fourth stem electrodes 82 arranged on the second substrate 20.

[0038] The third trunk electrode 81 extends along the second direction D2. The third trunk electrode 81 is located between two fourth electrodes 62 that are adjacent to each other in the first direction D1. The third trunk electrode 81 is spaced apart from the fourth electrodes 62 in a planar view. The third trunk electrodes 81 are aligned along the first direction D1. The third trunk electrode 81 overlaps with the first trunk electrode 51 in a planar view.

[0039] The third stem electrode 81 is electrically connected to the plurality of third electrodes 61. The third stem electrode 81 is integral with the plurality of third electrodes 61. The plurality of third electrodes 61 are electrically connected to the third stem electrode 81 so as to protrude from the third stem electrode 81 on both sides in the first direction D1.

[0040] The fourth trunk electrode 82 extends along the second direction D2. The fourth trunk electrode 82 is located between two adjacent third electrodes 61 in the first direction D1. The fourth trunk electrode 82 is spaced apart from the third electrodes 61 in a planar view. The multiple fourth trunk electrodes 82 are arranged along the first direction D1. The third trunk electrodes 81 and the fourth trunk electrodes 82 are arranged alternately in the first direction D1. The fourth trunk electrode 82 overlaps with the second trunk electrode 52 in a planar view.

[0041] The fourth stem electrode 82 is electrically connected to the plurality of fourth electrodes 62. The fourth stem electrode 82 is integral with the plurality of fourth electrodes 62. The plurality of fourth electrodes 62 are electrically connected to the fourth stem electrode 82 so as to protrude from the fourth stem electrode 82 on both sides in the first direction D1.

[0042] The third electrode 61, the fourth electrode 62, the third stem electrode 81, and the fourth stem electrode 82 are made of a conductive material having light transmission properties, such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGO (Indium Gallium Oxide), and IGZO (Indium Gallium Zinc Oxide).The third electrode 61, the fourth electrode 62, the third stem electrode 81, and the fourth stem electrode 82 may also be made of a conductive material, such as molybdenum tungsten alloy (MoW) and TAT (Ti / Al / Ti), which is a laminate of titanium (Ti) and aluminum (Al).

[0043] The third stem electrode 81 and the fourth stem electrode 82 are electrically connected to a control circuit (not shown). The control circuit applies a voltage to the third electrode 61 via the third stem electrode 81. The control circuit applies a voltage to the fourth electrode 62 via the fourth stem electrode 82.

[0044] 3 electrically insulates the third stem electrode 81 from the fourth stem electrode 82. The second insulating layer IL2 also electrically insulates the third electrode 61 from the fourth electrode 62.

[0045] The second alignment film AL2 is disposed on the rear surface side of the third electrode 61 and the fourth electrode 62. The second alignment film AL2 is disposed in a state spaced apart from the third electrode 61 and the fourth electrode 62. The second alignment film AL2 may be in contact with the third electrode 61 and the fourth electrode 62.

[0046] The light-shielding film 70 blocks the transmission of light. The light-shielding film 70 is conductive. The material of the light-shielding film 70 is a molybdenum-tungsten alloy (MoW) or the like. The light-shielding film 70 is located between the second substrate 20 and the second insulating layer IL2. The light-shielding film 70 overlaps with the gap G between two first electrode pairs 40 adjacent to each other in the second direction D2 in a plan view.

[0047] 5, the light-shielding film 70 is indicated by a dashed line. The light-shielding film 70 has a strip shape extending along the first direction D1.

[0048] The liquid crystal layer 30 shown in FIG. 3 is located between the first substrate 10 and the second substrate 20. The liquid crystal layer 30 is sandwiched between a first alignment film AL1 and a second alignment film AL2. 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 30 when no voltage is applied to the liquid crystal element 1. The initial alignment of the liquid crystal molecules LM is a direction in which the long axis Ax of the liquid crystal molecules LM is perpendicular to the third direction D3 (horizontal alignment). The alignment direction of the first alignment film AL1 and the alignment direction of the second alignment film AL2 are parallel to each other in a planar view.

[0049] The liquid crystal element 1 is an ECB (Electrically Controlled Birefringence) liquid crystal element, although it goes without saying that the liquid crystal element 1 is not limited to an ECB liquid crystal element.

[0050] Next, the operation of the liquid crystal element 1 when refracting the light L emitted from the light source S will be described. When a voltage is applied to the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62 by the control circuit, the liquid crystal element 1 refracts the light L. The light L is incident on the liquid crystal element 1 from the rear surface of the first substrate 10 along the third direction D3. The symbol in parentheses attached to the light L indicates the direction in which the light L travels. In addition, in FIG. 3, the light L emitted from the liquid crystal element 1 is shown on the +D3 side of the liquid crystal element 1.

[0051] When no voltage is applied to the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62, the alignment state of all the liquid crystal molecules LM contained in the liquid crystal layer 30 is the initial alignment (horizontal alignment), and the tilt degrees of all the liquid crystal molecules LM are equal to one another. Therefore, the phase change amount of the output light L passing through the liquid crystal layer 30 is equal at all parts of the liquid crystal layer 30, and no phase difference occurs in the output light L. Therefore, the liquid crystal element 1 outputs the output light L without refracting it. Specifically, as shown in FIG. 3, the liquid crystal element 1 outputs the output light L incident along the third direction D3 along the third direction D3 without refracting it.

[0052] When the liquid crystal element 1 refracts light L emitted from the light source S, voltages are applied to the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62 so that the magnitude of a first potential difference between the potential of the first electrode 41 and the potential of the third electrode 61 is different from the magnitude of a second potential difference between the potential of the second electrode 42 and the potential of the fourth electrode 62. Hereinafter, when the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62 are described without distinction, they will be simply referred to as electrodes.

[0053] Specifically, when the liquid crystal element 1 refracts the emitted light L so that it travels along a fourth direction D4 that is inclined toward the -D2 side relative to the third direction D3, a voltage is applied to the electrodes so that the magnitude of the second potential difference is greater than the magnitude of the first potential difference.

[0054] FIG. 6 is a diagram showing the degree of tilt of the liquid crystal molecules LM when the liquid crystal element 1 refracts the emitted light L along the fourth direction D4. In FIG. 6, the liquid crystal molecules LM are shown only by the long axes Ax of the liquid crystal molecules LM. FIG. 6 also shows the equipotential lines Lv of the electric field generated in the liquid crystal layer 30. As described above, the initial orientation of the liquid crystal molecules LM is horizontal. Therefore, when no voltage is applied to the electrodes, the long axes Ax of the liquid crystal molecules LM are aligned along the second direction D2.

[0055] When a voltage is applied to the electrodes, an electric field acts on the liquid crystal layer 30, causing the liquid crystal molecules LM to tilt. The greater the magnitude of the potential difference in the third direction D3 in the liquid crystal layer 30, the greater the degree of tilt of the liquid crystal molecules LM (the angle formed by the major axis Ax of the liquid crystal molecules LM and the second direction D2 becomes larger).

[0056] Also, the greater the degree of tilt of the liquid crystal molecules LM, the more the phase of the outgoing light L passing through the liquid crystal layer 30 advances. That is, the greater the magnitude of the potential difference in the third direction D3 in the liquid crystal layer 30, the more the phase of the outgoing light L advances.

[0057] FIG. 6 shows a state in which a voltage is applied to the electrodes such that the magnitude of the second potential difference (ED2) between the second electrode 42 and the fourth electrode 62 is greater than the magnitude of the first potential difference (ED1) between the first electrode 41 and the third electrode 61 (ED1 < ED2). Therefore, in FIG. 6, the degree of tilt of the liquid crystal molecules LM between the second electrode 42 and the fourth electrode 62 is greater than the degree of tilt of the liquid crystal molecules LM between the first electrode 41 and the third electrode 61. Also, the magnitude of the potential difference in the third direction D3 and the degree of tilt of the liquid crystal molecules LM increase as going from the first electrode 41 toward the second electrode in the second direction D2.

[0058] Also, voltages are applied to the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62 such that the potential of the first electrode 41 is different from the potential of the second electrode 42, and the potential of the third electrode 61 is different from the potential of the fourth electrode 62. That is, a potential difference occurs between the potential of the first electrode 41 and the potential of the second electrode 42. Also, a potential difference occurs between the potential of the third electrode 61 and the potential of the fourth electrode 62.

[0059] FIG. 6 shows a state in which a voltage is applied to the electrodes such that the potential (E2) of the second electrode 42 is greater than the potential (E1) of the first electrode 41 (E1 < E2), and the potential (E3) of the third electrode 61 is greater than the potential (E4) of the fourth electrode 62 (E4 < E3).

[0060] In FIG. 6, the potential (E3) of the third electrode 61 is higher than the potential (E1) of the first electrode 41 (E1 < E3), the potential (E1) of the first electrode 41 is higher than the potential (E4) of the fourth electrode 62 (E4 < E1), and the potential (E2) of the second electrode 42 is equal to the potential (E3) of the third electrode 61 (E2 = E3). That is, the relationship between the potentials of the electrodes in FIG. 6 is represented by the following formula (1).

[0061] E4 < E1 < E2 = E3 ···(1)

[0062] Furthermore, in FIG. 6, as represented by formula (2), the potential (E2) of the second electrode 42 and the potential (E4) of the fourth electrode 62 are equal in magnitude and opposite in polarity to each other.

[0063] E2 = (-1) × E4 ···(2)

[0064] When the relationship between the potentials of the electrodes satisfies the relationships of formulas (1) and (2), it becomes possible to control the potentials of the electrodes by a column inversion driving method in which the polarities of the potentials of the electrodes are periodically inverted. Needless to say, the relationship between the potentials of the electrodes is not limited to the relationships of formulas (1) and (2).

[0065] FIG. 7 is a diagram showing the phase difference of the emitted light L passing through the liquid crystal layer 30 of the liquid crystal element 1 shown in FIG. 6. In FIG. 7, the relationship between the potentials of the electrodes is as shown in formulas (1) and (2), and a case is shown where a voltage is applied to the electrodes such that the magnitude (ED2) of the second potential difference is twice the magnitude (ED1) of the first potential difference. The vertical axis in FIG. 7 indicates the phase difference of the emitted light L. The horizontal axis in FIG. 7 indicates the position in the second direction D2 of the liquid crystal layer 30. In FIG. 7, the range of "(41)" indicates the range of the first electrode 41 in the second direction D2, and the range of "(42)" indicates the range of the second electrode 42 in the second direction D2. In FIG. 7, the phase difference of the emitted light L passing through the liquid crystal layer 30, with the phase of the emitted light L passing between the first electrode 41 and the third electrode 61 related to the liquid crystal element 1 as a reference (zero), is shown by a solid line.

[0066] As shown in Fig. 7, since the magnitude of the second potential difference is larger than that of the first potential difference (ED1 < ED2), the phase difference between the first electrode 41 and the second electrode 42 increases as it goes from the first electrode 41 toward the +D2 side. That is, the phase of the emitted light L passing through the liquid crystal layer 30 advances as it goes from the first electrode 41 toward the +D2 side between the first electrode 41 and the second electrode 42. Thereby, the emitted light L is refracted so as to be emitted along the fourth direction D4.

[0067] On the other hand, when the emitted light L is refracted so as to advance along the fifth direction D5 in which the liquid crystal element 1 is inclined toward the +D2 side with respect to the third direction D3, a voltage is applied to the electrodes so that the magnitude of the first potential difference becomes larger than that of the second potential difference (ED2 < ED1). Also, in this case, voltages are applied to the first electrode 41, the second electrode 42, the third electrode 61, and the fourth electrode 62 such that the potential of the first electrode 41 and the potential of the second electrode 42 are different from each other, and the potential of the third electrode 61 and the potential of the fourth electrode 62 are different from each other. Note that, in this case, the relationship between the potentials of the electrodes may be the relationship expressed by the following formulas (3) and (4).

[0068] E3 < E2 < E1 = E4 ···(3)

[0069] E1 = (-1) × E3 ···(4)

[0070] When the relationship between the potentials of the electrodes satisfies the relationships of formulas (3) and (4), it becomes possible to control the potentials of the electrodes by a column inversion driving method in which the polarities of the potentials of the electrodes are periodically inverted. Needless to say, the relationship between the potentials of the electrodes is not limited to the relationships of formulas (3) and (4).

[0071] Since the magnitude of the first potential difference is larger than that of the second potential difference, the phase difference along the third direction D3 increases as it goes from the second electrode toward the -D2 side between the first electrode 41 and the second electrode 42. That is, the phase of the emitted light L passing through the liquid crystal layer 30 advances as it goes from the second electrode 42 toward the -D2 side between the first electrode 41 and the second electrode 42. Thereby, the emitted light L is refracted so as to be emitted along the fifth direction D5.

[0072] In this way, the liquid crystal element 1 can easily adjust the emission direction of the emitted light L by controlling the voltage applied to the electrodes.

[0073] Next, the configuration of the liquid crystal element 2 of the comparative example will be described.

[0074] 8 is a cross-sectional view of a comparative liquid crystal element 2. The comparative liquid crystal element 2 differs from the above-described liquid crystal element 1 in that it does not include the third electrode 61 and the fourth electrode 62, but includes a fifth electrode 180.

[0075] The fifth electrode 180 is disposed between the second substrate 20 and the second alignment film AL2, and overlaps with the plurality of first electrode groups 40 in plan view.

[0076] When the liquid crystal element 2 of the comparative example refracts light L emitted from the light source S, voltages are applied to the first electrode 41, the second electrode 42, and the fifth electrode 180 so that the magnitude of a third potential difference between the potential of the first electrode 41 and the potential of the fifth electrode 180 differs from the magnitude of a fourth potential difference between the potential of the second electrode 42 and the potential of the fifth electrode 180. In other words, voltages are applied to the electrodes so that the potential of the first electrode 41 differs from the potential of the second electrode 42.

[0077] For example, when the liquid crystal element 2 of the comparative example refracts the emitted light L so that it travels along the fifth direction D5, voltages are applied to the electrodes so that the magnitude of the third potential difference is greater than the magnitude of the fourth potential difference.

[0078] 9 is a diagram showing the degree of tilt of the liquid crystal molecules LM when the liquid crystal element 2 of the comparative example refracts the emitted light L along the fourth direction D4. Note that in FIG. 9, the potential of the first electrode 41 is equal to the potential (E1) of the first electrode 41 shown in FIG. 6, and the potential of the second electrode 42 is equal to the potential (E2) of the second electrode 42 shown in FIG. 6. That is, in FIG. 9, the potential of the second electrode 42 is greater than the potential of the first electrode 41. Also, in FIG. 9, the potential of the fifth electrode 180 is equal to the potential (E1) of the first electrode 41. Therefore, the magnitude of the fourth potential difference (ED4 (=|E2-E1|)) is greater than the magnitude of the third potential difference (ED3 (=|E1-E1|)) (ED4>ED3).

[0079] Next, the liquid crystal element 1 shown in Fig. 6 will be compared with the liquid crystal element 2 of the comparative example shown in Fig. 9. The potential (E1) of the first electrode 41 and the potential (E2) of the second electrode 42 of the liquid crystal element 1 are equal to the potential (E1) of the first electrode 41 and the potential (E2) of the second electrode 42 of the liquid crystal element 2 of the comparative example.

[0080] Furthermore, the magnitude of the second potential difference (ED2 (=|E2-E4|)) of the above liquid crystal element 1 is greater than the magnitude of the fourth potential difference (ED4 (=|E2-E1|)) of the liquid crystal element 2 of the comparative example (ED2>ED4). As a result, the tilt degree (θ1: Figure 6) of the liquid crystal molecules LM between the second electrode 42 and the fourth electrode 62 in the above liquid crystal element 1 is greater than the tilt degree (θ2: Figure 9) of the liquid crystal molecules LM between the second electrode 42 and the fifth electrode 180 in the liquid crystal element 2 of the comparative example (θ1>θ2).

[0081] Furthermore, in the above-described liquid crystal element 1, the potential (E3) of the third electrode 61 and the potential (E4) of the fourth electrode 62 are different from each other, so that a potential difference occurs in the second direction D2 between the adjacent third electrode 61 and fourth electrode 62. This potential difference acts on the liquid crystal molecules LM between the first electrode 41 and the third electrode 61 so as to reduce the tilt degree (θ3: FIG. 6) of the liquid crystal molecules LM.

[0082] On the other hand, the liquid crystal element 2 of the comparative example does not include the third electrode 61 as described above, but includes the fifth electrode 180. Therefore, no potential difference occurs in the second direction D2 near the fifth electrode 180. Therefore, the tilt degree (θ3: FIG. 6) of the liquid crystal molecules LM between the first electrode 41 and the third electrode 61 in the above-described liquid crystal element 1 is smaller (θ3<θ4) than the tilt degree (θ4: FIG. 9) of the liquid crystal molecules LM between the first electrode 41 and the fifth electrode 180 in the liquid crystal element 2 of the comparative example.

[0083] In Fig. 7, the phase difference of the emitted light L passing through the liquid crystal layer 30 of the liquid crystal element 2 of the comparative example shown in Fig. 9 is shown by a broken line. Specifically, in Fig. 7, the phase difference of the emitted light L passing through the liquid crystal layer 30 of the liquid crystal element 2 of the comparative example, with the phase of the emitted light L passing between the first electrode 41 and the fifth electrode 180 being taken as the reference (zero), is shown by a broken line. In Fig. 7, the portion where the broken line showing the phase difference of the emitted light L of the liquid crystal element 2 of the comparative example overlaps with the solid line showing the phase difference of the emitted light L of the liquid crystal element 1 is shown by a solid line.

[0084] Since the tilt degrees of the liquid crystal molecules LM between the liquid crystal element 1 and the comparative liquid crystal element 2 have the above relationship (θ1>θ2, θ3<θ4), the difference in the tilt degrees of the liquid crystal molecules LM between the first electrode 41 and the second electrode 42 in the liquid crystal element 1 (θ1-θ3) is larger than the difference in the tilt degrees (θ2-θ4) in the comparative liquid crystal element 2. Therefore, as shown in Fig. 7, the maximum value of the retardation in the liquid crystal element 1 (PD1) is larger than the maximum value of the retardation in the comparative liquid crystal element 2 (PD2).

[0085] As described above, the potential (E1) of the first electrode 41 and the potential (E2) of the second electrode 42 of the liquid crystal element 1 are equal to the potential (E1) of the first electrode 41 and the potential (E2) of the second electrode 42 of the liquid crystal element 2 of the comparative example. Furthermore, the magnitude (ED1) of the first potential difference between the potential (E1) of the first electrode 41 and the potential (E3) of the third electrode 61 of the liquid crystal element 1 is equal to the magnitude (ED4) of the fourth potential difference between the potential (E2 (=E3)) of the second electrode 42 and the potential (E1) of the fifth electrode 180 of the liquid crystal element 2 of the comparative example. This means that the liquid crystal element 1 can refract the emitted light L more efficiently than the liquid crystal element 2 of the comparative example.

[0086] 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.

[0087] For example, a voltage may be applied to the electrodes so that the potential of the third electrode 61 and the potential of the fourth electrode 62 are equal.

[0088] The light-shielding film 70 may also be disposed on the first substrate 10.

[0089] 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. [Explanation of symbols]

[0090] 1 Liquid crystal element 10 First board 20 Second board 30 Liquid crystal layer 40 1st electrode group 41 1st electrode 42 2nd electrode 60 2nd electrode set 61 3rd electrode 62 4th electrode 70 Light-shielding film D1 1st direction D2 2nd direction G Gap

Claims

1. a first substrate and a second substrate facing each other; a plurality of first electrode sets disposed on the first substrate, each set including a first electrode and a second electrode; a plurality of second electrode sets disposed on the second substrate and including a third electrode and a fourth electrode; a liquid crystal layer between the first substrate and the second substrate; a plurality of light-shielding films that block the transmission of light; In each of the plurality of first electrode sets, the first electrode and the second electrode extend along a first direction and face each other in a second direction perpendicular to the first direction, the plurality of first electrode sets and the plurality of second electrode sets are each aligned along the second direction, the first electrode included in one of the plurality of first electrode sets overlaps with the third electrode included in one of the plurality of second electrode sets in a plan view; the second electrode included in the one first electrode set overlaps with the fourth electrode included in the one second electrode set; the light-shielding film overlaps, in a plan view, a gap between two first electrode pairs adjacent to each other in the second direction among the plurality of first electrode pairs; Liquid crystal element.

2. a length in the second direction between the first electrode and the second electrode included in one first electrode set is greater than a length in the second direction between two first electrode sets adjacent to each other in the second direction among the plurality of first electrode sets; The liquid crystal device according to claim 1 .

3. Voltages are applied to the first electrode, the second electrode, the third electrode, and the fourth electrode such that a first potential difference between a potential of the first electrode and a potential of the third electrode and a second potential difference between a potential of the second electrode and a potential of the fourth electrode are different from each other. The liquid crystal device according to claim 1 .

4. voltages are applied to the first electrode, the second electrode, the third electrode, and the fourth electrode such that a potential of the first electrode and a potential of the second electrode are different from each other and a potential of the third electrode and a potential of the fourth electrode are different from each other; The liquid crystal device according to claim 1 .

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