Liquid crystal light deflection device and method for manufacturing liquid crystal light deflection device

Abstract

A liquid crystal light deflection device includes a first substrate including a first electrode, a second substrate including a second electrode, and a liquid crystal sandwiched between the first substrate and the second substrate. A high resistivity layer is provided on at least one of the first electrode or the second electrode. The high resistivity layer is sequentially covered by a first barrier layer formed of a metal oxide and a second barrier layer formed of a metal nitride or a metal carbide.

Description

Technical Field

[0001] The present application relates to a liquid crystal light deflecting device and a method for manufacturing the liquid crystal light deflecting device. Background Art

[0002] It is known that a liquid crystal light deflection device acts as a lens, a prism, etc., and produces a light deflection effect by changing the arrangement of liquid crystal. For example, unexamined Japanese patent application publication No. 2011-17742 discloses a low-voltage driven liquid crystal lens, which includes a first substrate having a first electrode, a second electrode, and a liquid crystal layer inserted between the first substrate and the second electrode. Using the low-voltage driven liquid crystal lens of unexamined Japanese patent application publication No. 2011-17742, when a voltage is applied to the first electrode and the second electrode, the arrangement of the liquid crystal layer changes. As a result, a light deflection effect occurs in the low-voltage driven liquid crystal lens. Therefore, the low-voltage driven liquid crystal lens acts on light as a convex lens or a concave lens.

[0003] In Unexamined Japanese Patent Application Publication No. 2011-17742, the driving voltage of the liquid crystal lens is reduced by placing a high resistivity layer on the side of the liquid crystal layer facing the transparent insulating layer provided between the second electrode and the liquid crystal layer. Using the low voltage driving liquid crystal lens of Unexamined Japanese Patent Application Publication No. 2011-17742, there is a risk that the light deflection effect (i.e., focal length) may change over time due to deterioration of the high resistivity layer caused by moisture, heat, etc., because the high resistivity layer is formed of zinc oxide, titanium oxide, etc.

[0004] In view of the above circumstances, an object of the present disclosure is to provide a liquid crystal light deflecting device and a method of manufacturing the liquid crystal light deflecting device capable of preventing or suppressing temporal variation in light deflection effect. Summary of the invention

[0005] In order to achieve the above object, the liquid crystal light deflection device in the first aspect of the present disclosure includes:

[0006] a first substrate including a first electrode;

[0007] a second substrate including a second electrode; and

[0008] The liquid crystal is sandwiched between the first substrate and the second substrate.

[0009] in,

[0010] a high resistivity layer is disposed on at least one of the first electrode or the second electrode, and

[0011] The high resistivity layer is sequentially covered by a first barrier layer formed of a metal oxide and a second barrier layer formed of a metal nitride or a metal carbide.

[0012] A method for manufacturing a liquid crystal light deflecting device in a second aspect of the present disclosure includes:

[0013] preparing a first substrate including a first electrode and a second substrate including a second electrode;

[0014] forming a high resistivity layer on at least one of the first electrode or the second electrode;

[0015] forming a first barrier layer formed of a metal oxide to cover the high resistivity layer so that a surface of the high resistivity layer is not exposed from the first barrier layer; and

[0016] A second barrier layer formed of metal nitride or metal carbide is formed on the first barrier layer.

[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the disclosure.

[0018] Since the high resistivity layer is sequentially covered by the first barrier layer formed of metal oxide and the second barrier layer formed of metal nitride or metal carbide, it is possible to prevent or suppress the light deflection effect from changing with time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A more complete understanding of the present application can be obtained when the following detailed description is considered in conjunction with the following drawings,

[0020] in:

[0021] Figure 1 is a schematic diagram showing a cross section of a liquid crystal light deflecting device according to Example 1;

[0022] Figure 2 is a top view of a second substrate according to Example 1;

[0023] Figure 3 is a schematic diagram showing the operation of the liquid crystal light deflecting device according to Embodiment 1;

[0024] Figure 4 is a flowchart showing a method of manufacturing a liquid crystal light deflecting device according to Embodiment 1;

[0025] Figure 5 is a schematic diagram showing a cross section of a liquid crystal light deflecting device according to Example 2;

[0026] Figure 6 is a top view of a second substrate according to Example 2;

[0027] Figure 7 is a schematic diagram showing the operation of the liquid crystal light deflecting device according to Embodiment 2;

[0028] Figure 8is a schematic diagram showing a cross section of a liquid crystal light deflecting device according to a modified example;

[0029] Fig. 9 is a diagram showing a second electrode of a second substrate according to a modified example;

[0030] Fig.10 is a diagram showing a first electrode of a first substrate according to a modified example;

[0031] Fig.11 is a cross-sectional view showing a high resistivity layer according to a modified example;

[0032] Fig.12 is a cross-sectional view showing a first barrier layer and a second barrier layer according to a modified example;

[0033] Fig.13 is a cross-sectional view showing a third barrier layer according to a modified example;

[0034] Fig.14 is a schematic diagram showing a cross section of a liquid crystal light deflecting device according to an example of an embodiment;

[0035] Fig.15 is a diagram showing materials included in a layer and thicknesses of the layers of an embodiment example and a comparative example;

[0036] Fig.16 is a graph showing evaluation results of sheet resistance of high resistivity layers of embodiment examples and comparative examples;

[0037] Fig.17 is a diagram showing evaluation results of focal length according to Embodiment Example 1;

[0038] Fig.18 is a diagram showing evaluation results of focal length according to Embodiment Example 2; and

[0039] Fig.19 is a graph showing evaluation results of focal length according to a comparative example. DETAILED DESCRIPTION

[0040] Hereinafter, a liquid crystal light deflecting device according to an embodiment is described with reference to the accompanying drawings.

[0041] Example 1

[0042] refer to Figures 1 to 4 The liquid crystal light deflection device 100 according to this embodiment is described. Figure 1As shown, the liquid crystal light deflection device 100 includes a first substrate 10, a second substrate 20 and a liquid crystal 30. The first substrate 10 includes a first electrode 12 and an alignment film 15. The second substrate 20 includes second electrodes 22 and 24, an insulating layer 26, a high resistivity layer 40, a first barrier layer 50, a second barrier layer 60 and an alignment film 65. The high resistivity layer 40 is disposed on the second electrodes 22 and 24. In addition, the high resistivity layer 40 is sequentially covered by the first barrier layer 50 and the second barrier layer 60. Using the liquid crystal light deflection device 100, a light deflection effect is generated by a change in the arrangement of the liquid crystal 30. Due to the light deflection effect, the liquid crystal light deflection device 100 acts on the light as a cylindrical lens. The liquid crystal light deflection device 100 is, for example, mounted on a liquid crystal display panel. The liquid crystal light deflection device 100 is used as a cylindrical lens array, which switches the display image to be displayed on the liquid crystal display between a planar image and a three-dimensional image. In the present disclosure, for ease of understanding, Figure 1 The longitudinal right direction of the liquid crystal light deflection device 100 ( Figure 1 The direction to the right) is defined as the +X direction, and the upward direction ( Figure 1 The direction toward the top) is defined as the +Z direction, and the direction perpendicular to the +X and +Z directions ( Figure 1 The forward direction) is defined as the +Y direction.

[0043] The first substrate 10 has transparency. In the present embodiment, the first substrate 10 allows visible light to pass therethrough. The first substrate 10 is, for example, a flat substrate made of glass. The first substrate 10 and the second substrate 20 are bonded together by a sealing material 70. The first substrate 10 and the second substrate 20 sandwich a liquid crystal 30 therebetween. The first substrate 10 includes a first electrode 12 and an alignment film 15.

[0044] The first electrode 12 of the first substrate 10 is rectangularly formed of indium tin oxide (ITO) on the first main surface 10a of the first substrate 10. The first electrode 12 is opposite to the comb-tooth portion 22a of the second electrode 22 and the comb-tooth portion 24a of the second electrode 24 (which is further described below). The first electrode 12 is connected to a controller not shown.

[0045] The alignment film 15 of the first substrate 10 is provided on the first major surface 10a and the first electrode 12. The alignment film 15 aligns the liquid crystal 30 in the X direction. The alignment film 15 is, for example, a polyimide alignment film subjected to a rubbing treatment.

[0046] The second substrate 20 is similar to the first substrate 10 and has transparency. In the present embodiment, the second substrate 20 allows visible light to pass therethrough. The second substrate 20 is, for example, a flat substrate made of glass. The second substrate 20 is bonded to the first substrate 10 through a sealing material 70, thereby sandwiching the liquid crystal 30. The second substrate 20 includes two second electrodes 22 and 24, an insulating layer 26, a high resistivity layer 40, a first barrier layer 50, a second barrier layer 60, and an alignment film 65. The insulating layer 26, the high resistivity layer 40, the first barrier layer 50, and the second barrier layer 60 allow visible light to pass therethrough.

[0047] The second electrode 22 and the second electrode 24 of the second substrate 20 are formed of ITO on the first main surface 20a of the second substrate 20 into comb-shaped teeth. Figure 2 As shown, the second electrode 22 and the second electrode 24 have a comb-shaped tooth portion 22a and a comb-shaped tooth portion 24a, respectively. The comb-shaped tooth portion 22a extends in the +Y direction, and the comb-shaped tooth portion 24a extends in the -Y direction. The comb-shaped tooth portion 22a and the comb-shaped tooth portion 24a are placed alternately and parallel to each other in the X direction.

[0048] like Figure 1 and Figure 2 As shown, the second electrodes 22 and 24 are covered by an insulating layer 26. The second electrodes 22 and 24, similar to the first electrode 12, are connected to a controller.

[0049] like Figure 1 As shown, the insulating layer 26 of the second substrate 20 covers the second electrodes 22 and 24. The insulating layer 26 insulates the second electrodes 22 and 24 from the high resistivity layer 40. The insulating layer 26 is made of silicon oxide (SiO2), aluminum nitride (AlN), silicon nitride (SiN X ), magnesium fluoride (MgF2), etc. The insulating layer 26 is, for example, a silicon oxide film. The thickness of the insulating layer 26 is, for example, 50 nm to 1000 nm.

[0050] The high resistivity layer 40 of the second substrate 20 is provided on the second electrodes 22 and 24 via the insulating layer 26. The high resistivity layer 40 is sequentially covered by the first barrier layer 50 and the second barrier layer 60. The high resistivity layer 40 has a thickness of, for example, 1×10 6 Ω / sq to 1×10 14 The high resistivity layer 40 is formed of Al-doped zinc oxide (AZO), zinc oxide (ZnO), indium tin (InSn) oxide, magnesium oxide (MgO), etc. The high resistivity layer 40 is, for example, an AZO film. For example, the high resistivity layer 40 has a thickness of 20 nm to 500 nm.

[0051] The first barrier layer 50 of the second substrate 20 covers the high resistivity layer 40. Figure 1As shown, the first barrier layer 50 preferably covers not only the top surface (the surface on the +Z side) but also the side surfaces of the high resistivity layer 40. In addition, the first barrier layer 50 preferably covers the high resistivity layer 40 so that the surface of the high resistivity layer 40 is not exposed from the first barrier layer 50. As described below, the first barrier layer 50 protects the high resistivity layer 40 in the case where the second barrier layer 60 is to be formed.

[0052] The first barrier layer 50 is formed of a metal oxide. Examples of the metal oxide include silicon oxide, aluminum oxide (AlO x ), tantalum oxide (TaO x ), niobium oxide (NbO x ), titanium oxide (TiO2), zirconium oxide (ZrO2), a mixture thereof, etc. The first barrier layer 50 is, for example, a silicon oxide film. For example, the first barrier layer 50 has a thickness of 10 nm to 500 nm.

[0053] The second barrier layer 60 of the second substrate 20 covers the first barrier layer 50 and the high resistivity layer 40. Figure 1 As shown, the second barrier layer 60 preferably covers not only the top surface (the surface on the +Z side) but also the side surface of the first barrier layer 50. In addition, it is preferred that the second barrier layer 60 and the high resistivity layer 40 do not contact each other. The second barrier layer 60 is formed of a metal nitride or a metal carbide. Examples of metal nitrides and metal carbides include silicon nitride, silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon carbide (SiC), mixtures thereof, and the like. The second barrier layer 60 is, for example, a silicon nitride film. For example, the second barrier layer 60 has a thickness of 50 nm to 500 nm.

[0054] The second barrier layer 60 protects the high resistivity layer 40 from moisture, and since the second barrier layer 60 is formed of a metal nitride or a metal carbide having excellent moisture resistance, the deterioration of the high resistivity layer 40 can be prevented or suppressed. In the present embodiment, since the second barrier layer 60 can prevent or suppress the deterioration of the high resistivity layer 40, the light deflection effect (focal length) of the liquid crystal light deflection device 100 can be prevented or suppressed from changing over time. When the second barrier layer 60 formed of a metal nitride or a metal carbide is formed directly on the high resistivity layer 40, there is a risk of changing the resistance value of the high resistivity layer 40 due to decomposition products (e.g., hydrogen) generated in the formation of the second barrier layer 60. In the present embodiment, since the first barrier layer 50 covers the high resistivity layer 40, the resistance value of the high resistivity layer 40 can be prevented or suppressed from changing in the film forming process of the second barrier layer 60. In addition, the yield in the manufacture of the liquid crystal light deflection device 100 can be improved.

[0055] The alignment film 65 of the second substrate 20 is provided on the second barrier layer 60. The alignment film 65, similar to the alignment film 15 of the first substrate 10, aligns the liquid crystal 30 in the X direction. The alignment film 65 is, for example, a polyimide alignment film subjected to a rubbing process.

[0056] The liquid crystal 30 is sandwiched between the first substrate 10 and the second substrate 20. The liquid crystal 30 is, for example, a positive nematic liquid crystal. The liquid crystal 30 is aligned in the X direction by the alignment film 15 and the alignment film 65.

[0057] Here, the operation of the liquid crystal light deflecting device 100 is described.

[0058] For example, when the controller brings the potentials of the first electrode 12 of the first substrate 10 and the second electrodes 22 and 24 of the second substrate 20 to the same potential (e.g., ground potential), no voltage is applied to the liquid crystal 30, and thus the liquid crystal 30 remains aligned in the X direction. When the liquid crystal 30 remains aligned in the X direction, no deflection effect is generated, and thus the liquid crystal light deflection device 100 does not act as a lens on light.

[0059] The voltages applied to the first electrode 12 of the first substrate 10 and the second electrode 22 of the second substrate 20 and the voltages applied to the first electrode 12 of the first substrate 10 and the second electrode 24 of the second substrate 20 are independently controlled so that a potential in the shape of a quadratic curve is formed between the first substrate 10 and the second substrate 20. Figure 3 As shown, the potential formed in the shape of a quadratic curve causes the molecules M of the liquid crystal 30 to align. In the liquid crystal light deflection device 100, this change in the arrangement of the liquid crystal 30 produces a refractive index distribution along the potential in the shape of a quadratic curve. In the liquid crystal light deflection device 100, the refractive index distribution along the potential in the shape of a quadratic curve produces a deflection effect. By doing so, the liquid crystal light deflection device 100 acts on light as a lens.

[0060] Next, refer to Figure 4 A method of manufacturing the liquid crystal light deflecting device 100 is described. Figure 4 is a flowchart showing a manufacturing process of the liquid crystal light deflecting device 100. The manufacturing process of the liquid crystal light deflecting device 100 includes a step of preparing a first substrate 10 and a second substrate 20 (step S10), a step of forming an insulating layer 26 (step S20), a step of forming a high resistivity layer 40 (step S30), a step of forming a first barrier layer 50 formed of a metal oxide (step S40), and a step of forming a second barrier layer 60 formed of a metal nitride or a metal carbide (step S50). The method of manufacturing the liquid crystal light deflecting device 100 also includes a step of forming an alignment film 15 and an alignment film 65 (step S60), and a step of bonding the first substrate 10 and the second substrate 20 together and injecting the liquid crystal 30 therein (step S70).

[0061] In step S10, a first substrate 10 including a first electrode 12 and a second substrate 20 including second electrodes 22 and 24 are prepared. For example, the first electrode 12 and the second electrodes 22 and 24 are formed of ITO by using a sputtering technique.

[0062] In step S20, an insulating layer 26 is formed on the second electrodes 22 and 24 of the second substrate 20. For example, the insulating layer 26 is formed of silicon oxide by using a sputtering technique.

[0063] In step S30, the high resistivity layer 40 is formed on the insulating layer 26. By doing so, the high resistivity layer 40 is disposed on the second electrodes 22 and 24 through the insulating layer 26. For example, the high resistivity layer 40 is formed of AZO by using a sputtering technique.

[0064] In step S40, the first barrier layer 50 is formed by covering the high resistivity layer 40 so that the surface of the high resistivity layer 40 is not exposed. The first barrier layer 50 is formed of a metal oxide. The first barrier layer 50 is, for example, a silicon oxide film formed by chemical vapor deposition (CVD). In the present embodiment, since the first barrier layer 50 covers the high resistivity layer 40, the first barrier layer 50 protects the high resistivity layer 40 from the decomposition product (e.g., hydrogen) generated during the formation of the second barrier layer 60 (step S50), thereby preventing or suppressing the change in the resistance value of the high resistivity layer 40. Therefore, the yield in the manufacture of the liquid crystal light deflection device 100 can be improved.

[0065] In step S50, the second barrier layer 60 is formed on the first barrier layer 50. By doing so, the high resistivity layer 40 is sequentially covered by the first barrier layer 50 and the second barrier layer 60. The second barrier layer 60 is formed of a metal nitride or a metal carbide. The second barrier layer 60 is, for example, a silicon nitride film formed by CVD. In the present embodiment, since the second barrier layer 60 covers the high resistivity layer 40, the high resistivity layer 40 is protected from moisture, so that the deterioration of the high resistivity layer 40 can be prevented or suppressed. In addition, the light deflection effect (focal length) of the liquid crystal light deflection device 100 can be prevented from changing over time.

[0066] In step S60, an alignment film 15 is formed on the first electrode 12 of the first substrate 10, and an alignment film 65 is formed on the second barrier layer 60. In step S60, a polyimide film is first formed by applying a polyimide material to the first electrode 12 and / or the second barrier layer 60, and then firing the applied polyimide material. Then, the alignment films 15 and 65 are formed by rubbing the polyimide film.

[0067] In step S70, the first substrate 10 and the second substrate 20 are bonded together via a spacer (not shown) through the sealing material 70. Then, the liquid crystal 30 is injected between the first substrate 10 and the second substrate 20. As described above, the liquid crystal light deflection device 100 can be manufactured.

[0068] As described above, since the second barrier layer 60 having excellent moisture-proof performance protects the high resistivity layer 40 from moisture, the deterioration of the high resistivity layer 40 can be prevented or suppressed, and the light deflection effect (focal length) of the liquid crystal light deflection device 100 can be prevented or suppressed from changing over time. In addition, since the first barrier layer 50 covers the high resistivity layer 40, the resistance value of the high resistivity layer 40 can be prevented or suppressed from changing in the film forming process of the second barrier layer 60. In addition, the yield in the manufacture of the liquid crystal light deflection device 100 can be improved.

[0069] In the case where only the first barrier layer 50 covers the high resistivity layer 40, it is necessary to increase the thickness of the first barrier layer 50 to protect the high resistivity layer 40 from moisture. Therefore, when the high resistivity layer 40 is covered only by the first barrier layer 50, the driving voltage increases. In addition, the time taken for the first barrier layer 50 to form increases. In the present embodiment, since the second barrier layer 60 covers the high resistivity layer 40, the thickness of the first barrier layer 50 can be reduced. Therefore, the time taken for the first barrier layer 50 to form can be shortened. In addition, the driving voltage of the liquid crystal light deflection device 100 can be reduced. In addition, by increasing the relative dielectric constant of one of the first barrier layer 50 and the second barrier layer 60, the driving voltage of the liquid crystal light deflection device 100 can be easily reduced.

[0070] Example 2

[0071] In Embodiment 1, although the liquid crystal light deflection device 100 acts on light as a lens, the liquid crystal light deflection device 100 may act on light as a prism.

[0072] With the liquid crystal light deflection device 100 of the present embodiment, a light deflection effect is produced by a change in the arrangement of the liquid crystal 30. The liquid crystal light deflection device 100 of the present embodiment acts on light as a prism. In the present embodiment, the configuration of the second electrodes 22 and 24 of the second substrate 20 and the high resistivity layer 40 is different from the configuration of the second electrodes 22 and 24 of the second substrate 20 and the high resistivity layer 40 of Embodiment 1. Other aspects of the configuration of the present embodiment are similar to those of Embodiment 1. Here, the second electrodes 22 and 24 of the second substrate 20 and the high resistivity layer 40 are described.

[0073] The second electrodes 22 and 24 of the second substrate 20 of this embodiment, which are similar to the second electrodes 22 and 24 of Example 1, are formed into comb-like teeth from ITO on the first main surface 20a of the second substrate 20. The second electrode 22 and the second electrode 24 respectively have a comb-like tooth portion 22a extending in the +Y direction and a comb-like tooth portion 24a extending in the -Y direction. The comb-tooth portions 22a and the comb-tooth portions 24a, which are similar to the comb-tooth portions 22a and the comb-tooth portions 24a of Example 1, are placed alternately and parallel to each other in the X direction. In this embodiment, the comb-tooth portions 22a and the comb-tooth portions 24a form an electrode pair 28, and the comb-tooth portions 22a of one electrode pair 28 are placed adjacent to the comb-tooth portions 24a of the other electrode pair 28, as shown in FIG. Figure 5 and Figure 6 As shown. Figure 6 In order to facilitate understanding, the insulating layer 26 is omitted.

[0074] In this embodiment, the second substrate 20 includes two high resistivity layers 40, such as Figure 5 and Figure 6 Each of the high resistivity layers 40 is provided on one electrode pair 28 (the comb-teeth portion 22a of the second electrode 22 and the comb-teeth portion 24a of the second electrode 24) through the insulating layer 26.

[0075] Next, the operation of the liquid crystal light deflecting device 100 of the present embodiment is described.

[0076] Similar to the liquid crystal light deflection device 100 of Embodiment 1, when the potentials of the first electrode 12 of the first substrate 10 and the second electrodes 22 and 24 of the second substrate 20 are brought to the same potential (e.g., ground potential), the liquid crystal 30 remains aligned in the X direction. When the liquid crystal 30 remains aligned in the X direction, no deflection effect is generated, and thus the liquid crystal light deflection device 100 does not act on light as a prism.

[0077] Independently controlling the voltage applied to the first electrode 12 of the first substrate 10 and the second electrode 22 of the second substrate 20 and the voltage applied to the first electrode 12 of the first substrate 10 and the second electrode 24 of the second substrate 20 causes a potential gradient to be formed between the comb-tooth portion 22a and the comb-tooth portion 24a of one electrode pair 28. For example, assuming that the first electrode 12 is at a ground potential (0 V), a first voltage is applied to the second electrode 22, and a second voltage greater than the first voltage is applied to the second electrode 24. In this case, a linear potential gradient is formed between the comb-tooth portion 22a and the comb-tooth portion 24a of one electrode pair 28 because the high resistivity layer 40 is provided on the one electrode pair 28 via the insulating layer 26. Due to the formed linear potential gradient, the molecules M of the liquid crystal 30 are as follows. Figure 7This change in the arrangement of the liquid crystal 30 generates a linear refractive index gradient. Therefore, the liquid crystal light deflecting device 100 refracts light incident from the first substrate 10 or the second substrate 20. That is, the liquid crystal light deflecting device 100 of the present embodiment acts on light as a prism.

[0078] As described above, in the liquid crystal light deflection device 100 of the present embodiment, the light deflection effect is generated by the change in the arrangement of the liquid crystal 30. The liquid crystal light deflection device 100 of the present embodiment acts on light as a prism. In addition, similar to the embodiment 1, since the second barrier layer 60 having excellent moisture resistance protects the high resistivity layer 40 from moisture, the deterioration of the high resistivity layer 40 can be prevented or suppressed, and the light deflection effect (deflection angle or refraction angle) of the liquid crystal light deflection device 100 can be prevented or suppressed from changing over time. Since the first barrier layer 50 covers the high resistivity layer 40, the resistance value of the high resistivity layer 40 can be prevented or suppressed from changing in the film forming process of the second barrier layer 60. In addition, the yield in the manufacture of the liquid crystal light deflection device 100 can be improved. In addition, similar to the embodiment 1, the time taken to form the first barrier layer 50 can be shortened, and the driving voltage of the liquid crystal light deflection device 100 can be reduced.

[0079] Modified Example

[0080] The above-described embodiments may be modified in various ways without departing from the gist of the present disclosure.

[0081] In Embodiment 1 and Embodiment 2, the high resistivity layer 40 disposed on the second electrodes 22 and 24 of the second substrate 20 is sequentially covered by the first barrier layer 50 and the second barrier layer 60. It is sufficient as long as the high resistivity layer 40 is disposed on at least one of the first electrode 12 of the first substrate 10 or the second electrodes 22 and 24 of the second substrate 20 and sequentially covered by the first barrier layer 50 and the second barrier layer 60. For example, Figure 8 As shown, the high resistivity layer 40 disposed on the first electrode 12 and the high resistivity layer 40 disposed on the second electrodes 22 and 24 may each be covered by the first barrier layer 50 and the second barrier layer 60 in sequence.

[0082] The electrodes to be disposed on the first substrate 10 and the second substrate 20 may be of any shape. For example, the second substrate 20 of Embodiment 1 may include an electrode having a shape of Fig. 9 The second electrode 72 is shown with an opening 72a instead of the second electrodes 22 and 24. In this case, the liquid crystal light deflecting device 100 acts on light as a convex lens or a concave lens.

[0083] In addition, the first substrate 10 of the first embodiment may include a Fig.10The two first electrodes 74 and 76 of the comb-like teeth shown in the figure are used instead of the first electrode 12. The first electrode 74 and the first electrode 76 include a comb-like tooth portion 74a and a comb-like tooth portion 76a, respectively. The high resistivity layer 40 is provided on the first electrodes 74 and 76. In addition, the high resistivity layer 40 is sequentially covered by the first barrier layer 50 and the second barrier layer 60. In this case, the liquid crystal light deflection device 100 acts on the light as a microlens. In addition, the liquid crystal light deflection device 100 also acts as a cylindrical lens capable of switching the deflection direction in two directions.

[0084] like Fig.11 As shown in FIG. 1 , the high resistivity layer 40 of Embodiment 1 may be divided into several parts. In Embodiment 2, one high resistivity layer 40 may be provided on two electrode pairs 28 via an insulating layer 26. Fig.12 As shown, the first barrier layer 50 and the second barrier layer 60 do not necessarily cover the side surfaces of the high resistivity layer 40 .

[0085] Although the second electrodes 22 and 24 are disposed on the first major surface 20a of the second substrate 20, the second electrodes 22 and 24 may be formed on the third barrier layer 80 disposed on the first major surface 20a of the second substrate 20, such as Fig.13 The third barrier layer 80 similar to the second barrier layer 60 is formed of metal nitride or metal carbide. By doing so, even if the second substrate 20 is a substrate through which moisture easily passes (for example, a plastic substrate), the high resistivity layer 40 can be protected.

[0086] In Embodiment 1 and Embodiment 2, although the alignment films 15 and 65 align the liquid crystal 30 in the X direction, the direction in which the alignment films 15 and 65 align the liquid crystal 30 is not limited to the X direction. It is sufficient as long as the alignment films 15 and 65 of Embodiment 1 and Embodiment 2 align the liquid crystal 30 in a uniform arrangement. For example, the alignment films 15 and 65 may align the liquid crystal 30 in the Y direction.

[0087] While the above describes certain examples of preferred embodiments, this detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0088] Example of embodiment

[0089] Although the following example embodiments describe the present disclosure in greater detail, the example embodiments should be viewed in an illustrative rather than a restrictive sense.

[0090] As an example of an embodiment, a Fig.14The liquid crystal light deflection device 100 of Example 1 shown. High temperature and high humidity evaluation was performed on the created liquid crystal light deflection device 100. Specifically, the created liquid crystal light deflection device 100 was exposed to an environment of 60°C and 90% humidity for a predetermined period of time, and then the sheet resistance of the high resistivity layer 40 and the focal length of the liquid crystal light deflection device 100 were measured. In addition, as a comparative example, a liquid crystal light deflection device was created, which had a configuration similar to that of the embodiment except that the first barrier layer 50 and the second barrier layer 60 were not present. The liquid crystal light deflection device of the comparative example was evaluated for high temperature and high humidity in a manner similar to that of the embodiment example.

[0091] exist Fig.15 2 shows the thickness of the layers and the materials constituting the layers of the liquid crystal light deflection device 100 of the embodiment example and the liquid crystal light deflection device of the comparative example.

[0092] The liquid crystal light deflecting device 100 of Embodiment Example 1 and the liquid crystal light deflecting device 100 of Embodiment Example 2 have different composition ratios of AZO included in the high resistivity layer 40. Likewise, the liquid crystal light deflecting device 100 of Comparative Example 1 and the liquid crystal light deflecting device 100 of Comparative Example 2 have different composition ratios of AZO included in the high resistivity layer 40.

[0093] In addition, the width D1 of the comb-tooth portion 22a of the second electrode 22 is set to 10 μm, and the width D2 of the comb-tooth portion 24a of the second electrode 24 is set to 116.9 μm. In addition, the interval D3 between the comb-tooth portion 22a and the comb-tooth portion 24a is set to 10 μm. In addition, the thickness D4 of the liquid crystal 30 is set to 20 μm.

[0094] The focal length was measured at frequencies from 1 Hz to 1500 Hz while applying a voltage of 5 V to the comb-teeth portions 22 a of the first and second electrodes 12 and 22 and applying a voltage of 1.5 V to the comb-teeth portions 24 a of the first and second electrodes 12 and 24 .

[0095] Next, evaluation results of the liquid crystal light deflecting device 100 of the embodiment example and the liquid crystal light deflecting device 100 of the comparative example are described.

[0096] Fig.16 Evaluation examples of the sheet resistance of the high resistivity layer 40 in the embodiment example and the comparative example are shown. Fig.16As shown, the sheet resistance of the high resistivity layer 40 in the liquid crystal light deflecting device 100 in the embodiment examples 1 and 2 does not change even after being exposed to an environment of 60° C. and 90% humidity for not less than 2000 hours. In contrast, the sheet resistance of the high resistivity layer 40 in the liquid crystal light deflecting device in the comparative examples 1 and 2 varies greatly up and down. Therefore, the deterioration of the high resistivity layer 40 can be prevented or suppressed by sequentially covering the high resistivity layer 40 with the first barrier layer 50 formed of a metal oxide and the second barrier layer 60 formed of a metal nitride or a metal carbide.

[0097] Fig.17 : is a diagram showing the evaluation results of the focal length in the liquid crystal light deflection device 100 of Example 1 of the embodiment. Fig.18 The evaluation results of the focal length in the liquid crystal light deflecting device 100 of Embodiment Example 2 are shown. In addition, Fig.19 Evaluation results of focal lengths in the liquid crystal light deflecting devices 100 of Comparative Examples 1 and 2 are shown.

[0098] like Fig.17 and 18 As shown, using the liquid crystal light deflection device 100 of Examples 1 and 2, the focal length remains substantially the same even when exposed to an environment of 60° C. and 90% humidity for not less than 2000 hours. Fig.19 As shown, using the liquid crystal light deflection devices of Comparative Examples 1 and 2, the focal length changes by no more than 300 μm. Therefore, the first barrier layer 50 formed of metal oxide and the second barrier layer 60 formed of metal nitride or metal carbide sequentially covering the high resistivity layer 40 can prevent or suppress the focal length of the liquid crystal light deflection device 100 from changing over time. That is, this can prevent or suppress the light deflection effect from changing over time. Fig.19 The focal lengths measurable at the same frequency are shown because the frequency at which the focal lengths can be measured varies with the liquid crystal light deflecting devices of Comparative Examples 1 and 2.

[0099] As described above, the first barrier layer 50 formed of metal oxide and the second barrier layer 60 formed of metal nitride or metal carbide sequentially covering the high resistivity layer 40 can prevent or inhibit the deterioration of the high resistivity layer 40, and can prevent or inhibit the light deflection effect of the liquid crystal light deflection device 100 from changing over time.

[0100] For the purpose of explanation, some example embodiments have been described above. Although the foregoing discussion has presented specific embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the broader spirit and scope of the present invention. Therefore, the description and drawings are to be regarded as illustrative rather than restrictive. Therefore, this detailed description should not be understood in a limiting sense, and the scope of the present invention is limited only by the included claims and the full scope of equivalents to which these claims are entitled.

Claims

1. A liquid crystal light deflection device, comprising: a first substrate including a first electrode; a second substrate including a second electrode; as well as liquid crystal sandwiched between the first substrate and the second substrate, in, An insulating layer and a high resistivity layer are sequentially disposed on at least one of the first electrode or the second electrode, The high resistivity layer is sequentially covered by a first barrier layer formed of a metal oxide and a second barrier layer formed of a metal nitride or a metal carbide, and The first barrier layer covers a top surface and side surfaces of the high resistivity layer such that the top surface and side surfaces of the high resistivity layer are not exposed from the first barrier layer.

2. The liquid crystal light deflection device according to claim 1, wherein: The second barrier layer and the high resistivity layer do not contact each other.

3. The liquid crystal light deflection device according to claim 1 or 2, wherein: At least one of the first electrode or the second electrode is disposed on a third barrier layer formed of a metal nitride or a metal carbide.

4. The liquid crystal light deflection device according to claim 1 or 2, wherein: The first barrier layer is formed of at least one of silicon oxide, aluminum oxide, tantalum oxide, niobium oxide, titanium oxide or zirconium oxide.

5. The liquid crystal light deflection device according to claim 1 or 2, wherein: The second barrier layer is formed of at least one of silicon nitride, silicon oxynitride, silicon carbonitride or silicon carbide.

6. The liquid crystal light deflection device according to claim 1, wherein: The second electrode includes two comb-tooth electrodes each having a comb-tooth shape, The comb-teeth portions of one of the two comb-teeth electrodes and the comb-teeth portions of the other of the two comb-teeth electrodes are placed alternately and in parallel with each other, One of the comb-teeth portions of the one comb-teeth electrode and one of the comb-teeth portions of the other comb-teeth electrode form an electrode pair, For each electrode pair, each of the plurality of high resistivity layers is disposed on the electrode pair through the insulating layer, and By applying different voltages between the first electrode and the one comb-teeth electrode and between the first electrode and the other comb-teeth electrode, a potential gradient is formed between the comb-teeth portions of the one comb-teeth electrode and the other comb-teeth electrode forming the electrode pair.

7. A method for manufacturing a liquid crystal light deflection device, comprising: preparing a first substrate including a first electrode and a second substrate including a second electrode; forming an insulating layer on at least one of the first electrode or the second electrode; forming a high resistivity layer on the insulating layer; forming a first barrier layer formed of a metal oxide to cover a top surface and side surfaces of the high resistivity layer so that the top surface and side surfaces of the high resistivity layer are not exposed from the first barrier layer; as well as A second barrier layer formed of metal nitride or metal carbide is formed on the first barrier layer.

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