Liquid crystal element

Abstract

To provide a liquid crystal element that can deflect light suitably.SOLUTION: A liquid crystal element 1 includes a plurality of electric resistance films 40 that are arranged in a first direction D1 and a second direction D2, which is orthogonal to the first direction D1, in a plan view and have the shape that is longer in the first direction D1 than in the second direction D2, a plurality of first electrodes 50 including a first stem part 51 extending along the second direction D2 and a first branch part 52 projecting from the first stem part 51 to both sides in the first direction D1, and a plurality of second electrodes 60 including a second stem part 61 extending along the second direction D2 and a second branch part 62 projecting from the second stem part 61 to both sides in the first direction D1. In each of the electric resistance films 40, the first stem part 51 and the second stem part 61 exist on opposite sides with the electric resistance film 40 held therebetween in the first direction D1. The first branch part 52 and the second branch part 62 are electrically connected to the electric resistance film 40 in a state of facing each other in the second direction D2.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a liquid crystal element.

Background Art

[0002] Patent Document 1 discloses a liquid crystal element that refracts incident light and emits it. When a voltage is applied to the first electrode and the second electrode of the liquid crystal element, a potential gradient is generated in the high-resistance layer, and the liquid crystal molecules are tilted. The incident light is refracted by the tilt of the liquid crystal molecules.

[0003] The first electrode and the second electrode are linear and extend in a state parallel to each other. Further, the high-resistance layer overlaps the first electrode and the second electrode in a plan view. The direction of the potential gradient is orthogonal to the direction in which the electrodes (the first electrode and the second electrode) extend.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the liquid crystal element of Patent Document 1, when the resistance ratio described below is relatively small, a potential gradient is not appropriately generated in the high-resistance layer (electric resistance film), and light is not appropriately refracted. The resistance ratio is the ratio of the electric resistance value of the electric resistance film in the direction of the potential gradient to the electric resistance value of the electrode in the direction orthogonal to the potential gradient. The smaller the length in the direction of the potential gradient between the first electrode and the second electrode is with respect to the length in the direction orthogonal to the potential gradient at the portion where the electric resistance film is electrically connected to the electrode in the electric resistance film, the smaller the resistance ratio becomes.

[0006] An object of the present disclosure is to provide a liquid crystal element capable of appropriately refracting light.

Means for Solving the Problems

[0007] The liquid crystal element of the present disclosure includes a first substrate and a second substrate that overlap each other in plan view, and a liquid crystal layer between the first substrate and the second substrate. The first substrate has a plurality of electric resistance films arranged along a first direction and a second direction orthogonal to the first direction in plan view, and having a shape in which the length in the first direction is longer than the length in the second direction, a first main part extending along the second direction, and a plurality of first electrodes having first branch parts protruding from both sides of the first main part in the first direction, a second main part extending along the second direction, and a plurality of second electrodes having second branch parts protruding from both sides of the second main part in the first direction. In each of the plurality of electric resistance films, the first main part and the second main part are on opposite sides of the electric resistance film across the electric resistance film in the first direction, and the first branch part and the second branch part are electrically connected to the electric resistance film in a state of facing each other in the second direction.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited by the content described in the following embodiments. In addition, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be combined as appropriate.

[0010] It should be noted that the disclosure is merely an example, and those that can be easily conceived by those skilled in the art with appropriate modifications while maintaining the gist of the present disclosure are naturally included in the scope of the present disclosure. In addition, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present disclosure. Also, in this specification and each drawing, the same reference numerals may be assigned to the same elements as those described above with respect to the previously shown drawings, 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 plane of the substrate included in the liquid crystal element 1. In each direction, the side indicated by the arrow corresponds to the + side, and the opposite side corresponds to the - side. The + side and the - side of the first direction D1, and the + side and the - side of the second direction D2 correspond to the sides of the liquid crystal element 1. The third direction D3 corresponds to the thickness direction of the liquid crystal element 1. The + side of the third direction D3 corresponds to the front side of the liquid crystal element 1, and the - side of the third direction D3 corresponds to the back side of the liquid crystal element 1. Further, in this specification, "plan view" means looking at the liquid crystal element 1 along the third direction D3. Note that the directions of 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.

[0012] Figure 1 is a conceptual diagram of the liquid crystal element 1 according to an embodiment of the present disclosure. The liquid crystal element 1 is a refractive plate that refracts light. Incident light L emitted from a light source S is incident on the liquid crystal element 1. The light source S is, for example, an illumination device such as a vehicle headlight and a spotlight.

[0013] When no voltage is applied, the liquid crystal element 1 transmits the incident light L without changing the direction (emission direction) in which the incident light L travels, as indicated by the solid-line arrow. On the other hand, when a voltage is applied, the liquid crystal element 1 refracts the incident light L so as to travel along one of the two directions indicated by the dashed-line arrows (details will be described later).

[0014] Figure 2 is a plan view of the liquid crystal element 1 according to an embodiment of the present disclosure. Figure 3 is a cross-sectional view of the liquid crystal element 1 taken along line III-III shown in Figure 2. The cross-sectional view of the liquid crystal element 1 shown in Figure 3 shows the cross-sectional shape of the liquid crystal element 1 cut in a plane orthogonal to the first direction D1.

[0015] The liquid crystal element 1 includes a first substrate 10, a second substrate 20, and a liquid crystal layer 30.

[0016] The first substrate 10 and the second substrate 20 overlap each other in plan view. The first substrate 10 and the second substrate 20 have light-transmitting properties. The first substrate 10 and the second substrate 20 are, for example, glass substrates, resin substrates, or resin films.

[0017] On the first substrate 10, a plurality of electric resistance films 40, a plurality of first electrodes 50, a plurality of second electrodes 60, an insulating layer IL, and a first alignment film AL1 are arranged.

[0018] As shown in FIG. 2, the plurality of electric resistance films 40 are arranged in a matrix along the first direction D1 and the second direction D2 in a plan view. The electric resistance film 40 has a rectangular shape in which the length in the first direction D1 is longer than the length in the second direction D2 in a plan view. In a plan view, the plurality of electric resistance films 40 overlap with a refraction region RA that refracts the emitted light L.

[0019] FIG. 3 shows four electric resistance films 40 arranged along the second direction D2. The first electric resistance film 40a, the second electric resistance film 40b, the third electric resistance film 40c, and the fourth electric resistance film 40d shown in FIG. 3 are arranged in this order from the - side to the + side along the second direction D2.

[0020] The electric resistance value of the electric resistance film 40 is larger than the electric resistance values of the first electrode 50 and the second electrode 60. The material of the electric resistance film 40 is a light-transmissive conductive material such as zinc oxide (ZnO) and indium gallium zinc oxide (IGZO), for example.

[0021] As shown in FIG. 3, the first electrode 50 and the second electrode 60 are arranged on the back side of the electric resistance film 40.

[0022] FIG. 4 is a plan view showing the configurations of the electric resistance film 40, the first electrode 50, and the second electrode 60. The first electrode 50 integrally has a first trunk portion 51 and a plurality of first branch portions 52.

[0023] The first trunk portion 51 extends along the second direction D2. The first trunk portion 51 is between two electric resistance films 40 adjacent to each other in the first direction D1. The first trunk portion 51 is separated from the electric resistance film 40 in a plan view.

[0024] The first branch portion 52 protrudes from the first trunk portion 51 to both sides in the first direction D1. The first branch portion 52 extends along the first direction D1. The first branch portion 52 is electrically connected to two electric resistance films 40 that are adjacent to each other with the first trunk portion 51 interposed therebetween in the first direction D1. As shown in FIGS. 3 and 4, the first branch portion 52 is electrically connected to the + side end portion of the electric resistance film 40 in the second direction D2. The first branch portion 52 is in contact with the electric resistance film 40.

[0025] As shown in FIG. 4, the second electrode 60 integrally has a second trunk portion 61 and a plurality of second branch portions 62.

[0026] The second trunk portion 61 extends along the second direction D2. The second trunk portion 61 is between two electric resistance films 40 that are adjacent to each other in the first direction D1. The second trunk portion 61 is separated from the electric resistance film 40 in a plan view.

[0027] The first trunk portion 51 and the second trunk portion 61 are on opposite sides of each of the plurality of electric resistance films 40 across the electric resistance film 40 in the first direction D1. In other words, the first trunk portion 51 and the second trunk portion 61 are arranged alternately in the first direction D1.

[0028] The second branch portion 62 protrudes from the second trunk portion 61 to both sides in the first direction D1. The second branch portion 62 extends along the first direction D1. The second branch portion 62 is electrically connected to two electric resistance films 40 that are adjacent to each other with the second trunk portion 61 interposed therebetween in the first direction D1. As shown in FIGS. 3 and 4, the second branch portion 62 is electrically connected to the - side end portion of the electric resistance film 40 in the second direction D2. The second branch portion 62 is in contact with the electric resistance film 40.

[0029] The first branch portion 52 and the second branch portion 62 are electrically connected to the electric resistance film 40 in a state of facing each other in the second direction D2 in each of the plurality of electric resistance films 40. Also, the length in the first direction D1 of the portion where the first branch portion 52 is electrically connected to the end portion of the electric resistance film 40 is equal to the length in the first direction D1 of the portion where the second branch portion 62 is electrically connected to the electric resistance film 40. Hereinafter, the length in the first direction D1 is referred to as the first electrode length.

[0030] Further, the cross-sectional shape of the first branch portion 52 and the cross-sectional shape of the second branch portion 62 are the same as each other. Therefore, the length of the first branch portion 52 in the second direction D2 and the length of the second branch portion 62 in the second direction D2 are equal to each other. Hereinafter, the length in the second direction D2 is referred to as the second electrode length.

[0031] The materials of the first electrode 50 and the second electrode 60 are conductive materials such as a molybdenum tungsten alloy (MoW) and a TAT (Ti / Al / Ti) in which titanium (Ti) and aluminum (Al) are laminated.

[0032] As shown in FIGS. 3 and 4, in the electric resistance film 40, a portion that overlaps with the first electrode 50 (first branch portion 52) in a plan view is defined as a first overlapping portion 41, a portion that overlaps with the second electrode 60 (second branch portion 62) in a plan view is defined as a second overlapping portion 42, and a portion between the first overlapping portion 41 and the second overlapping portion 42 is defined as an intermediate portion 43. In the second direction D2, the length of the intermediate portion 43 is longer than the combined length of the length of the first overlapping portion 41 and the length of the second overlapping portion 42.

[0033] In the present embodiment, in the second direction D2, the + side end of the first branch portion 52 is on the + side in the second direction D2 from the + side end of the electric resistance film 40, and the - side end of the second branch portion 62 is on the - side from the - side end of the electric resistance film 40. Note that, in the second direction D2, the + side end of the first branch portion 52 may coincide with the + side end of the electric resistance film 40, or the - side end of the second branch portion 62 may coincide with the - side end of the electric resistance film 40.

[0034] The insulating layer IL shown in FIG. 3 electrically insulates between the electric resistance film 40, the first stem portion 51, and the second stem portion 61. Further, the insulating layer IL electrically insulates between the first electrode 50 and the second electrode 60.

[0035] The first alignment film AL1 is disposed on the front side of the electric resistance film 40.

[0036] On the second substrate 20, a third electrode 70 and a second alignment film AL2 are disposed. The third electrode 70 overlaps a plurality of electric resistance films 40 in plan view.

[0037] The material of the third electrode 70 is a light-transmissive conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGO (Indium Gallium Oxide), and IGZO (Indium Gallium Zinc Oxide).

[0038] In addition, the electrical resistance value (hereinafter referred to as the film resistance value) and shape of the electric resistance film 40, and the electrical resistance value (hereinafter referred to as the electrode resistance value) and shape of the first electrode 50 and the second electrode 60 are determined so that the resistance ratio described below becomes an appropriate value. If the resistance ratio is not appropriately determined, the potential gradient described later does not appropriately occur in the electric resistance film 40, and the liquid crystal element 1 cannot appropriately refract the emitted light L.

[0039] The potential gradient generated in the electric resistance film 40 occurs along the second direction D2 between the first branch portion 52 and the second branch portion 62 in plan view. The first direction D1 is orthogonal to the direction in which the potential gradient occurs. The resistance ratio is the ratio of the film resistance value in the second direction D2 to the electrode resistance value in the first direction D1, and is represented by the following formula (1).

[0040] Ra = Rfd2 / Red1 ···(1)

[0041] In formula (1), Ra is the resistance ratio, Red1 is the electrode resistance value in the first direction D1, and Rfd2 is the film resistance value in the second direction D2.

[0042] In addition, the film resistance value (Rfd2) in the second direction D2 shown in formula (1) is represented by the following formula (2).

[0043] Rfd2 = Rf × (Lf2 / Lf1) ···(2)

[0044] In Equation (2), Rf is the film resistance value. Lf1 is the length in the first direction D1 of the site where the first electrode 50 (first branch portion 52) and the second electrode 60 (second branch portion 62) are electrically connected in the electric resistance film 40 (that is, it corresponds to the first electrode length). Lf2 is the length in which a potential gradient occurs in the electric resistance film 40, and is the length in the second direction D2 at the intermediate portion 43 between the first branch portion 52 and the second branch portion 62 in a plan view.

[0045] Furthermore, the electrode resistance value (Red1) in the first direction D1 shown in Equation (1) is represented by the following Equation (3).

[0046] Red1 = Re × (Le1 / Le2) ···(3)

[0047] In Equation (3), Re is the electrode resistance value, Le1 is the first electrode length (the length in the first direction D1 of the site where the electric resistance film 40 is electrically connected to the end portions of the first branch portion 52 and the second branch portion 62), and Le2 is the second electrode length (the length in the second direction D2 of the first branch portion 52 and the second branch portion 62).

[0048] To increase the refraction angle of the emitted light L, it is necessary to increase the potential gradient. To increase the potential gradient, the length (Lf2) in the second direction D2 of the electric resistance film 40 is shortened. On the other hand, the resistance ratio is appropriately in the range of 100 or more and 1000 or less. From Equations (1), (2), and (3), in the electric resistance film 40, the first branch portion 52, and the second branch portion 62, when the length (Lf2, Le2) in the second direction D2 is relatively short with respect to the length (Lf1, Le1) in the first direction D1, the resistance ratio becomes small and may fall below the appropriate range.

[0049] Therefore, the shapes of the electric resistance film 40, the first branch portion 52, and the second branch portion 62 are determined so that the resistance ratio is within an appropriate range, and the electric resistance films 40 are arranged in a matrix along the first direction D1 and the second direction D2. In other words, the electric resistance films 40 are arranged in a state of being divided into shapes in which the length (Lf2) in the second direction D2 with respect to the length (Lf1) in the first direction D1 is adjusted so that the resistance ratio is within an appropriate range.

[0050] As shown in FIG. 3, the second alignment film AL2 is disposed on the back side of the third electrode 70.

[0051] The liquid crystal layer 30 is between the first substrate 10 and the second substrate 20. The liquid crystal layer 30 is sandwiched between the first alignment film AL1 and the second alignment film AL2. The first alignment film AL1 and the second alignment film AL2 define the alignment (initial alignment) of the liquid crystal molecules LM contained in the liquid crystal layer 30 in a state where no voltage is applied to the liquid crystal element 1. 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 plan view.

[0052] The liquid crystal element 1 is an ECB (Electrically Controlled Birefringence) liquid crystal element. Needless to say, the liquid crystal element 1 is not limited to an ECB liquid crystal element.

[0053] Further, the liquid crystal element 1 further includes a light shielding film 80 and a photo spacer 90.

[0054] The light shielding film 80 blocks the transmission of light. The light shielding film 80 has conductivity. The material of the light shielding film 80 is molybdenum tungsten alloy (MoW) or the like. The light shielding film 80 is disposed on the second substrate 20. The light shielding film 80 is between the second substrate 20 and the third electrode 70.

[0055] FIG. 5 is a plan view showing the shape of the light shielding film 80. In FIG. 5, the light shielding film 80 is indicated by a one-dot chain line. As shown in FIGS. 3 and 5, the light shielding film 80 overlaps with the gap G between two adjacent electric resistance films 40 in plan view. Further, the light shielding film 80 overlaps with the first electrode 50 and the second electrode 60 in plan view. The light shielding film 80 integrally has a plurality of first light shielding portions 81 and a plurality of second light shielding portions 82.

[0056] The first light shielding portion 81 is strip-shaped and extends along the second direction D2. The first light shielding portion 81 overlaps with the gap G between two adjacent electric resistance films 40 in the first direction D1 in plan view. A plurality of first light shielding portions 81 are arranged in a plurality along the first direction D1.

[0057] The second light-shielding part 82 is strip-shaped and extends along the first direction D1. The second light-shielding part 82 connects two first light-shielding parts 81 adjacent to each other in the first direction D1. The second light-shielding part 82 overlaps with the gap G between two electric resistance films 40 adjacent to each other in the second direction D2 in a plan view.

[0058] A plurality of photospacer 90 are arranged between the first substrate 10 and the second substrate 20. The photospacer 90 is columnar and makes the thickness of the liquid crystal layer 30 constant. The photospacer 90 overlaps with the light-shielding film 80 in a plan view.

[0059] Next, the operation when the liquid crystal element 1 refracts the emitted light L of the light source S will be described. The emitted light L enters the liquid crystal element 1 from the back surface of the first substrate 10 along the third direction D3. The sign in parentheses attached to the emitted light L indicates the direction in which the emitted light L travels. Also, in FIG. 3, the arrow indicating the emitted light L emitted from the liquid crystal element 1 is shown on the + side of the third direction D3 with respect to the liquid crystal element 1.

[0060] When no potential is applied to the liquid crystal element 1, the emitted light L emitted from the liquid crystal element 1 travels along the third direction D3. On the other hand, when a potential is applied to the liquid crystal element 1, the emitted light L emitted from the liquid crystal element 1 travels along the fourth direction D4 or the fifth direction D5 as will be described later. In other words, when a potential is applied, the liquid crystal element 1 refracts the emitted light L along the fourth direction D4 or the fifth direction D5.

[0061] FIG. 6 is a diagram showing the potential of the electric resistance film 40 and the phase difference of the emitted light L passing through the liquid crystal layer 30 when the liquid crystal element 1 refracts the emitted light L along the fourth direction D4. The fourth direction D4 is a direction inclined to the + side of the second direction D2 with respect to the third direction D3 as shown in FIG. 3.

[0062] The points on the horizontal axis indicating the second direction D2 shown in FIG. 6 represent the positions in the second direction D2. Also, the arrows corresponding to the signs in parentheses shown in FIG. 6 indicate the ranges of the parts of the electric resistance film 40. Note that FIG. 3 also shows points representing the positions in the second direction D2.

[0063] The first point P1 and the second point P2 shown in FIGS. 3 and 6 correspond to the end on the - side of the first overlapping portion 41 and the end on the + side of the first overlapping portion 41 in the first electric resistance film 40a shown in FIG. 3.

[0064] The third point P3, the fourth point P4, the fifth point P5, and the sixth point P6 shown in FIGS. 3 and 6 correspond to the end on the - side of the second overlapping portion 42, the end on the + side of the second overlapping portion 42, the end on the - side of the first overlapping portion 41, and the end on the + side of the first overlapping portion 41 in the second electric resistance film 40b shown in FIG. 3.

[0065] The seventh point P7, the eighth point P8, the ninth point P9, and the tenth point P10 shown in FIGS. 3 and 6 correspond to the end on the - side of the second overlapping portion 42, the end on the + side of the second overlapping portion 42, the end on the - side of the first overlapping portion 41, and the end on the + side of the first overlapping portion 41 in the third electric resistance film 40c shown in FIG. 3.

[0066] The eleventh point P11 and the twelfth point P12 shown in FIGS. 3 and 6 correspond to the end on the - side of the second overlapping portion 42 and the end on the + side of the second overlapping portion 42 in the fourth electric resistance film 40d shown in FIG. 3.

[0067] When the liquid crystal element 1 refracts the emitted light L along the fourth direction D4, a first potential E1 is applied to the first electrode 50 and a second potential E2 higher than the first potential E1 is applied to the second electrode 60 by a control circuit (not shown).

[0068] In this case, in one electric resistance film 40, the potential of the second overlapping portion 42 (for example, the portion between the third point P3 and the fourth point P4 in the second electric resistance film 40b) in contact with the second electrode 60 is equal to the second potential E2. Also, in one electric resistance film 40, the potential of the intermediate portion 43 (for example, the portion between the fourth point P4 and the fifth point P5 in the second electric resistance film 40b) between the first electrode 50 and the second electrode 60 linearly changes from the second potential E2 to the first potential E1 from the - side to the + side in the second direction D2. Further, in one electric resistance film 40, the potential of the first overlapping portion 41 (for example, the portion between the fifth point P5 and the sixth point P6 in the second electric resistance film 40b) in contact with the first electrode 50 is equal to the first potential E1.

[0069] Also, by the control circuit, the first potential E1 is applied to the third electrode 70. The potential difference between the first potential E1 and the second potential E2 is determined based on the angle formed by the third direction D3 and the fourth direction D4. In other words, the degree of inclination of the fourth direction D4 with respect to the third direction D3 can be adjusted by the potential difference between the first potential E1 and the second potential E2.

[0070] The electric field generated by applying potentials to the first electrode 50, the second electrode 60, and the third electrode 70 acts on the liquid crystal layer 30, and the liquid crystal molecules LM are inclined. As a result, in the second direction D2, the refractive index of the emitted light L in the liquid crystal layer 30 changes, and a phase difference occurs in the emitted light L passing through the liquid crystal layer 30.

[0071] Regarding the phase of the emitted light L passing through the liquid crystal layer 30 shown in FIG. 6, with the phase at the position corresponding to the most + side end of one electric resistance film 40 (for example, the sixth point P6 in the second electric resistance film 40b) in the second direction D2 as a reference (that is, the phase difference is 0 (zero)), the maximum value of the phase difference generated by the potentials applied to the first electrode 50 and the second electrode 60 is defined as the first phase difference R1. Note that the solid line indicating the phase difference of the emitted light L shown in FIG. 6 indicates the locus of the same phase as the reference phase.

[0072] The retardation of the emitted light L passing through the liquid crystal layer 30 changes in a zigzag manner along the second direction D2 between 0 (zero) and the first retardation R1. Specifically, the retardation at the site of the liquid crystal layer 30 corresponding to the second overlapping site 42 is the first retardation R1. Also, the retardation at the site of the liquid crystal layer 30 corresponding to the intermediate site 43 changes from the first retardation R1 to 0 (zero) from the - side to the + side in the second direction D2. Furthermore, the retardation at the site of the liquid crystal layer 30 corresponding to the first overlapping site 41 is 0 (zero).

[0073] Note that the retardation between two adjacent electric resistance films 40 in the second direction D2 (for example, between the second point P2 and the third point P3) changes from 0 (zero) to the first retardation R1 from the - side to the + side in the second direction D2.

[0074] The degree of the inclination of the retardation at the site of the liquid crystal layer 30 corresponding to the intermediate site 43 corresponds to the angle formed by the third direction D3 and the fourth direction D4. Also, in the second direction D2, the length of the site of the liquid crystal layer 30 corresponding to the intermediate site 43 is longer than the combined length of the sites of the liquid crystal layer 30 corresponding to the first overlapping site 41 and the second overlapping site 42.

[0075] As shown in FIG. 6, due to the change in the retardation of the emitted light L passing through the liquid crystal layer 30, the emitted light L is refracted by the liquid crystal layer 30 and is emitted from the liquid crystal element 1 along the fourth direction D4.

[0076] FIG. 7 is a diagram showing the potential of the electric resistance film 40 and the retardation of the emitted light L passing through the liquid crystal layer 30 when the liquid crystal element 1 refracts the emitted light L along the fifth direction D5. The fifth direction D5 is a direction inclined to the - side of the second direction D2 with respect to the third direction D3 as shown in FIG. 3.

[0077] When the liquid crystal element 1 refracts the emitted light L along the fifth direction D5, the control circuit applies the second potential E2 to the first electrode 50 and the first potential E1 to the second electrode 60.

[0078] In this case, as shown in FIG. 7, in one electric resistance film 40, the potential of the second overlapping portion 42 (for example, the portion between the third point P3 and the fourth point P4 in the second electric resistance film 40b) that contacts the second electrode 60 is equal to the first potential E1. Also, in one electric resistance film 40, the potential of the intermediate portion 43 (for example, the portion between the fourth point P4 and the fifth point P5 in the second electric resistance film 40b) linearly changes from the first potential E1 to the second potential E2 in the second direction D2 from the - side to the + side. Further, in one electric resistance film 40, the potential of the first overlapping portion 41 (see FIG. 3: for example, the portion between the fifth point P5 and the sixth point P6 in the second electric resistance film 40b) that contacts the first electrode 50 is equal to the second potential E2.

[0079] Also, by the control circuit, the first potential E1 is applied to the third electrode 70. The potential difference between the first potential E1 and the second potential E2 is determined based on the angle formed by the third direction D3 and the fifth direction D5. Therefore, the degree of inclination of the fifth direction D5 with respect to the third direction D3 can be adjusted by the potential difference between the first potential E1 and the second potential E2.

[0080] When potentials are applied to the first electrode 50, the second electrode 60, and the third electrode 70, in the second direction D2, the refractive index of the emitted light L in the liquid crystal layer 30 changes, and a phase difference occurs in the emitted light L passing through the liquid crystal layer 30.

[0081] Regarding the phase of the emitted light L passing through the liquid crystal layer 30 shown in FIG. 7, with the phase at the position corresponding to the most - side end of one electric resistance film 40 (for example, the third point P3 in the second electric resistance film 40b) in the second direction D2 as the reference (that is, the phase difference is 0 (zero)), the maximum value of the phase difference generated by the potentials applied to the first electrode 50 and the second electrode 60 is defined as the first phase difference R1.

[0082] The retardation of the emitted light L passing through the liquid crystal layer 30 changes in a zigzag manner along the second direction D2 between 0 (zero) and the first retardation R1. Specifically, the retardation at the portion of the liquid crystal layer 30 corresponding to the second overlapping portion 42 is 0 (zero). The retardation at the portion of the liquid crystal layer 30 corresponding to the intermediate portion 43 changes from 0 (zero) to the first retardation R1 from the - side to the + side in the second direction D2. Furthermore, the retardation at the portion of the liquid crystal layer 30 corresponding to the first overlapping portion 41 is the first retardation R1.

[0083] Note that the retardation between two adjacent electric resistance films 40 in the second direction D2 changes linearly from the first retardation R1 to 0 (zero) from the - side to the + side in the second direction D2.

[0084] The degree of inclination of the retardation at the portion of the liquid crystal layer 30 corresponding to the intermediate portion 43 corresponds to the angle formed by the third direction D3 and the fifth direction D5.

[0085] As shown in FIG. 7, due to the change in the retardation of the emitted light L passing through the liquid crystal layer 30, the emitted light L is refracted by the liquid crystal layer 30 and emitted from the liquid crystal element 1 along the fifth direction D5.

[0086] By determining the shapes of the electric resistance film 40, the first branch portion 52, and the second branch portion 62 so that the resistance ratio is within an appropriate range as described above, an appropriate potential gradient is generated in the electric resistance film 40. Therefore, the liquid crystal element 1 can appropriately refract the emitted light L.

[0087] Also, the light-shielding film 80 can suppress the emitted light L from passing through the liquid crystal element 1 from the gap G between two adjacent electric resistance films 40 in plan view. Therefore, the emitted light L does not pass through the electric resistance film 40, and the liquid crystal element 1 can appropriately refract the emitted light L.

[0088] Further, the material of the light-shielding film 80 is a molybdenum-tungsten alloy (MoW), and the light-shielding film 80 can be made thinner compared to a material having no conductivity (for example, a resin material). Thereby, the height of the unevenness on the + side surface of the liquid crystal layer 30 in the third direction D3 can be reduced. Therefore, when the emitted light L is refracted so as to travel along the fourth direction D4, the emitted light L is suppressed from traveling in a direction other than the fourth direction D4 in the liquid crystal layer 30. Therefore, the liquid crystal element 1 can appropriately refract the emitted light L.

[0089] As described above, the photo spacer 90 overlaps the light-shielding film 80 in plan view. In this case, compared with the case where the photo spacer 90 is located at a position deviated from the light-shielding film 80 in plan view, it is possible to suppress the photo spacer 90 from blocking the emitted light L. Therefore, the liquid crystal element 1 can appropriately refract the emitted light L.

[0090] As described above, the preferred embodiments of the present disclosure have been described, but the present disclosure is not limited to such embodiments. The content disclosed in the embodiments is merely an example, and various modifications are possible without departing from the spirit of the present disclosure. Appropriate modifications made without departing from the spirit of the present disclosure also naturally belong to the technical scope of the present disclosure.

[0091] For example, the light-shielding film 80 may be disposed on the first substrate 10. In this case, the material of the light-shielding film 80 is a material having electrical insulation (for example, a resin material). Thereby, it is possible to prevent the light-shielding film 80 from affecting the potential gradient generated in the electric resistance film 40 by being located in the vicinity of the electric resistance film 40.

[0092] FIG. 8 is a plan view showing the configurations of the electric resistance film 40, the first electrode 50, and the second electrode 60 in the liquid crystal element 1 according to a modified example of the embodiment of the present disclosure. In this modified example, the first electrode 50 further includes a first connection portion 153 (corresponding to the "connection portion"). Further, the second electrode 60 further includes a second connection portion 163.

[0093] The first connecting portion 153 connects a plurality of first main portions 51 outside the plurality of electric resistance films 40 in a plan view. The first connecting portion 153 is in a strip shape extending along the first direction D1.

[0094] The second connecting portion 163 connects a plurality of second main portions 61 outside the plurality of electric resistance films 40 in a plan view. The second connecting portion 163 is in a strip shape extending along the first direction D1.

[0095] The first connecting portion 153 and the second connecting portion 163 are located on opposite sides of each other with the plurality of electric resistance films 40 interposed therebetween in the second direction D2.

[0096] FIG. 9 is a cross-sectional view of the liquid crystal element 1 according to another modification of the embodiment of the present disclosure. In this other modification, the first main portion 251 and the first branch portion 252 are separate from each other in the first electrode 250. The first main portion 251 is in a strip shape extending along the second direction D2. The first branch portion 252 is in a strip shape extending along the first direction D1. In the third direction D3, the first main portion 251 and the first branch portion 252 are at different positions from each other. In this other modification, the first branch portion 252 is between the first main portion 251 and the electric resistance film 40 in the third direction D3.

[0097] Also, in this other modification, the second main portion 261 and the second branch portion 262 are separate from each other in the second electrode 260. The second main portion 261 is in a strip shape extending along the second direction D2. The second branch portion 262 is in a strip shape extending along the first direction D1. In the third direction D3, the second main portion 261 and the second branch portion 262 are at different positions from each other. In this other modification, the second branch portion 262 is between the second main portion 261 and the electric resistance film 40 in the third direction D3.

[0098] FIG. 10 is a plan view showing the configuration of an electric resistance film 40, a first electrode 250, and a second electrode 260 according to another modification of the embodiment of the present disclosure. In a plan view, the arrangement of the electric resistance film 40, the first electrode 250, and the second electrode 260 is the same as the arrangement of the first electrode 50 and the second electrode 60 shown in FIG. 4. In the first electrode 250, the first main portion 251 and the first branch portion 252 are electrically connected to each other at a portion where they overlap in a plan view. In the second electrode 260, the second main portion 261 and the second branch portion 262 are electrically connected to each other at a portion where they overlap in a plan view.

[0099] Also, in this other modification, the materials of the first branch portion 52 and the second branch portion 62 may be a light-transmissive conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGO (Indium Gallium Oxide), and IGZO (Indium Gallium Zinc Oxide). In this case, the light transmittance of the liquid crystal element 1 can be improved, and the luminance of the emitted light L emitted from the liquid crystal element 1 can be improved.

[0100] Also, with regard to other operational effects brought about by the aspects described in the above embodiments, those that are obvious from the description in this specification or that can be appropriately conceived by those skilled in the art are naturally understood to be brought about by the present disclosure.

Description of Reference Numerals

[0101] 1 Liquid crystal element 10 First substrate 20 Second substrate 30 Liquid crystal layer 40 Electric resistance film 50 First electrode 51 First main portion 52 First branch portion 60 Second electrode 61 Second main portion 62 Second branch portion 70 Third electrode 80 Light-shielding film 90 Photo spacer 153 First connecting portion (connecting portion) 163 Second connecting part D1 First direction D2 Second direction D3 Third direction G Gap

Claims

1. A first substrate and a second substrate that overlap each other in plan view, and a liquid crystal layer disposed between the first substrate and the second substrate, wherein the first substrate includes a plurality of electric resistance films arranged along a first direction and a second direction orthogonal to the first direction in plan view, and having a shape in which the length in the first direction is longer than the length in the second direction, a plurality of first electrodes having a first main portion extending along the second direction and first branch portions protruding from both sides of the first main portion in the first direction, a plurality of second electrodes having a second main portion extending along the second direction and second branch portions protruding from both sides of the second main portion in the first direction, in each of the plurality of electric resistance films, the first main portion and the second main portion are on opposite sides of the electric resistance film in the first direction, the first branch portions and the second branch portions are electrically connected to the electric resistance film in a state of facing each other in the second direction, a liquid crystal element.

2. The first electrode further includes a connecting portion that connects the plurality of first main portions outside the plurality of electric resistance films in plan view, The liquid crystal element according to claim 1.

3. In a third direction orthogonal to the first direction and the second direction, the first main portion and the first branch portion are at different positions from each other, The liquid crystal element according to claim 1.

4. further comprising a light shielding film that overlaps a gap between two adjacent ones of the electric resistance films in plan view and blocks light transmission, The liquid crystal element according to claim 1.

5. The light shielding film is disposed on the second substrate and has conductivity, The liquid crystal element according to claim 4.

6. further comprising a photo spacer disposed between the first substrate and the second substrate, The photo spacer overlaps the light shielding film in plan view, The liquid crystal element according to claim 4.

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