Light direction control element and display device

Abstract

A light ray direction control element and a display device are disclosed. The light ray direction control element includes a first light-transmissive substrate, a second light-transmissive substrate facing the first light-transmissive substrate, a first light-transmissive region disposed on a first major surface of the first light-transmissive substrate, a second light-transmissive region disposed on a first major surface of the second light-transmissive substrate, a plurality of first light-absorbing regions positioned among the first light-transmissive region, and a plurality of second light-absorbing regions positioned among the second light-transmissive region. The light ray direction control element further includes a light-transmissive dispersion medium enclosed in the first light-absorbing regions and the second light-absorbing regions, and charged electrophoretic particles dispersed in the light-transmissive dispersion medium. When a cross-section perpendicular to the first major surface of the first light-transmissive substrate and the first major surface of the second light-transmissive substrate is observed, the first light-transmissive region and the second light-transmissive region can differ in shape or in angle of inclination with respect to the first major surface of the first light-transmissive substrate.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Japanese Patent Application No. 2021-11600, filed on January 28, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to light direction control elements and display devices. Background Technology

[0004] Light direction control elements that control the direction of transmitted light are known. For example, Japanese Patent No. 4899503 describes an optical element arranged on the front side of a liquid crystal display element, which controls the direction of light emitted from a surface-emitting light source and passing through the liquid crystal display element. The optical element of Japanese Patent No. 4899503 includes a pair of transparent substrates including transparent electrode films, and a composite material layer disposed between the pair of transparent substrates. The composite material layer is formed of a UV-curable polymer material and a liquid crystal material dispersed in the UV-curable polymer material. The composite material layer includes a first region having optical transparency and a second region adjacent to the first region. In the first region, the polymer material is cured in a state in which the liquid crystal particles are aligned with the direction facing the transparent substrate. In the second region, the orientation state of the liquid crystal material is electrically switched between a light-transmitting orientation state and a light-scattering orientation state.

[0005] In Japanese Patent No. 4899503, the viewing angle mode of an optical element is selectively switched by changing the orientation state of the liquid crystal material. Specifically, by setting the liquid crystal material to a light-transmitting orientation state, the viewing angle mode is switched to a first viewing angle mode, in which light from the liquid crystal element is emitted at a first angle. Alternatively, by setting the liquid crystal material to a light-scattering orientation state, the viewing angle mode is switched to a second viewing angle mode, in which light from the liquid crystal element is emitted at a second angle smaller than the first angle. The optical element of Japanese Patent No. 4899503 can emit light with two types of angular distributions. However, depending on the application, there is a need for an optical element capable of emitting light with multiple types of angular distributions.

[0006] This disclosure is made in view of the foregoing, and the purpose of this disclosure is to provide a light direction control element and a display device that can emit light in three or more types of angular distributions. Summary of the Invention

[0007] To achieve the above objective, the light direction control element according to the first aspect includes:

[0008] First light-transmitting substrate;

[0009] The second light-transmitting substrate faces the first light-transmitting substrate;

[0010] A first light-transmitting area is disposed on a first main surface of a first light-transmitting substrate and extends from the first light-transmitting substrate toward the second light-transmitting substrate.

[0011] The second light-transmitting area is disposed on the first main surface of the second light-transmitting substrate facing the first main surface of the first light-transmitting substrate, extends from the second light-transmitting substrate toward the first light-transmitting substrate, and is continuous with the first light-transmitting area.

[0012] Multiple first light-absorbing regions are positioned within a first light-transmitting region and extend from the first light-transmitting substrate toward the second light-transmitting substrate;

[0013] Multiple second light-absorbing regions are positioned within a second light-transmitting region, extending from the second light-transmitting substrate toward the first light-transmitting substrate, and are continuous with the first light-absorbing region.

[0014] A light-transmitting dispersion medium, which is confined within a first light-absorbing region and a second light-absorbing region; and

[0015] Charged electrophoretic particles are dispersed in a transparent dispersion medium and have a dispersion state that changes according to the applied voltage, wherein...

[0016] When observing the cross-section of the first main surface perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the shape and tilt angle of the first light-transmitting area and the second light-transmitting area relative to the first main surface of the first light-transmitting substrate will be different.

[0017] According to the second aspect, the display device includes:

[0018] The light direction control element as described above; and

[0019] Display panel, in which

[0020] The light direction control element is arranged on the display surface of the display panel.

[0021] According to the third aspect, the display device includes:

[0022] The light direction control element as described above;

[0023] Transmissive liquid crystal display panel;

[0024] The backlight is positioned on the side of the transmissive liquid crystal display panel opposite the display surface and supplies light to the transmissive liquid crystal display panel.

[0025] The light direction control element is arranged between the transmissive liquid crystal display panel and the backlight.

[0026] It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are not intended to limit this disclosure.

[0027] According to this disclosure, the first light-transmitting area and the second light-transmitting area have different shapes and tilt angles relative to the first main surface of the first light-transmitting substrate, and in this way, light can be emitted in three or more types of angular distributions. Attached Figure Description

[0028] A more complete understanding of this application can be obtained by considering the following detailed description in conjunction with the accompanying drawings, in which:

[0029] Figure 1 This is a schematic diagram showing the light direction control element according to Embodiment 1;

[0030] Figure 2 This is a cross-sectional view showing the light direction controller according to Embodiment 1;

[0031] Figure 3 This is a schematic diagram illustrating a display device according to Embodiment 1;

[0032] Figure 4 This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 1;

[0033] Figure 5 This is a schematic diagram illustrating the light blocking mode according to Embodiment 1;

[0034] Figure 6 This is a schematic diagram showing the first diagonal narrow field mode according to Embodiment 1;

[0035] Figure 7 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 1 in a plane parallel to the XZ plane;

[0036] Figure 8 This is a schematic diagram illustrating the first vertical narrow field mode according to Embodiment 1;

[0037] Figure 9 This is a schematic diagram illustrating the first wide-field mode according to Embodiment 1;

[0038] Figure 10 This is a schematic diagram illustrating the second wide-field mode according to Embodiment 1;

[0039] Figure 11 This is a flowchart illustrating a method for manufacturing a light direction control element according to Embodiment 1;

[0040] Figure 12This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 2;

[0041] Figure 13 This is a cross-sectional view showing the light direction controller according to Embodiment 2;

[0042] Figure 14 This is a schematic diagram illustrating the third diagonal narrow field mode according to Embodiment 2;

[0043] Figure 15 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 2 in a plane parallel to the XZ plane;

[0044] Figure 16 This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 3;

[0045] Figure 17 This is a schematic diagram illustrating the second vertical narrow field mode according to Embodiment 3;

[0046] Figure 18 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 3 in a plane parallel to the YZ plane;

[0047] Figure 19 This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 4;

[0048] Figure 20 This is a cross-sectional view showing the light direction controller according to Embodiment 4;

[0049] Figure 21 This is a schematic diagram illustrating the third vertical narrow field mode according to Embodiment 4;

[0050] Figure 22 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 4 in a plane parallel to the XZ plane;

[0051] Figure 23 This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 5;

[0052] Figure 24 This is a schematic diagram illustrating the sixth vertical narrow field mode according to Embodiment 5;

[0053] Figure 25 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 5 in a plane parallel to the YZ plane;

[0054] Figure 26 This is a perspective view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 6;

[0055] Figure 27 This is a schematic diagram illustrating the ninth vertical narrow field mode according to Embodiment 6;

[0056] Figure 28 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 6 in a plane parallel to the XZ plane;

[0057] Figure 29 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 6 in a plane parallel to the YZ plane;

[0058] Figure 30 This is a schematic diagram illustrating the tenth vertical narrow field mode according to Embodiment 6;

[0059] Figure 31 This is a schematic diagram illustrating the tenth vertical narrow field mode according to Embodiment 6;

[0060] Figure 32 This is a plan view showing the first light-transmitting area, the first light-absorbing area, and the second light-transmitting area according to Embodiment 7;

[0061] Figure 33 This is a side view showing the first light-transmitting area, the first light-absorbing area, the second light-transmitting area, and the second light-absorbing area according to Embodiment 7;

[0062] Figure 34 This is a schematic diagram illustrating the twelfth vertical narrow field mode according to Embodiment 7;

[0063] Figure 35 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 7 in a plane parallel to the XZ plane;

[0064] Figure 36 This is a diagram showing the angular distribution of the emitted light from the light direction control element according to Embodiment 7 in a plane parallel to the YZ plane;

[0065] Figure 37 This is a schematic diagram illustrating the fourteenth vertical narrow field mode according to Embodiment 7;

[0066] Figure 38 This is a cross-sectional view showing the light direction controller according to Embodiment 8;

[0067] Figure 39 This is a schematic diagram illustrating the fifth diagonal narrow field mode according to Embodiment 8;

[0068] Figure 40This is a schematic diagram illustrating the fifteenth vertical narrow field mode according to Embodiment 8;

[0069] Figure 41 This is a schematic diagram illustrating the fifteenth wide-field mode according to Embodiment 8;

[0070] Figure 42 This is a cross-sectional view showing a light direction controller according to an improved example; and

[0071] Figure 43 This is a schematic diagram illustrating a display device based on an improved example. Detailed Implementation

[0072] In the following description, with reference to the accompanying drawings, light direction control elements and display devices according to various embodiments are described.

[0073] Example 1

[0074] refer to Figure 1-11 Simultaneously, the light direction control element 200 according to this embodiment is described. For example... Figure 1 As shown, the light direction control element 200 includes a light direction controller 100 and a voltage controller 110. The light direction controller 100 controls the angular distribution of the transmitted light (i.e., the emitted light of the light direction controller 100). Figure 2 As shown, the light direction controller 100 includes a first light-transmitting substrate 10, a second light-transmitting substrate 20, a first light-transmitting region 32, a first light-absorbing region 34, a second light-transmitting region 42, and a second light-absorbing region 44. The light-transmitting dispersion medium 52 and the electrophoretic particles 54 are enclosed within the first light-absorbing region 34 and the second light-absorbing region 44. The voltage controller 110 controls the voltage applied to the electrophoretic particles 54. Note that in this embodiment, and in this description, for ease of understanding, [the following is used]... Figure 1 The light direction controller 100 refers to the rightward direction (rightward on the paper) as the "+X direction", the upward direction (upward on the paper) as the "+Z direction", and the direction perpendicular to the +X and +Z directions (depth direction on the paper) as the "+Y direction". Additionally, the +X, -X, +Y, and -Y directions can also be referred to as the leftward, rightward, upward, and downward directions, respectively.

[0075] like Figure 3 As shown, the light direction control element 200 and the display panel 210 constitute the display device 300. The display device 300 is installed in a smartphone, laptop computer, vehicle, information display, or the like. The display panel 210 displays text, images, and the like. The display panel 210 is implemented as a liquid crystal display panel, an organic electroluminescent (EL) display panel, or the like.

[0076] The light direction control element 200 controls the angular distribution of light emitted from the display panel 210 and transmitted through the light direction controller 100. The light direction controller 100 of the light direction control element 200 is arranged on the display surface of the display panel 210.

[0077] Back Figure 2 The first light-transmitting substrate 10 of the light direction controller 100 transmits visible light. In one example, the first light-transmitting substrate 10 is implemented as a flat glass substrate. The first light-transmitting substrate 10 includes a first light-transmitting electrode 12 on a first main surface 10a. In this embodiment, the first light-transmitting electrode 12 is formed over the entire first main surface 10a. The first light-transmitting electrode 12 is formed of indium tin oxide (ITO). In addition, an insulating layer (not shown) is disposed on the first light-transmitting electrode 12. In one example, the insulating layer is formed of silicon dioxide (SiO2).

[0078] Similar to the first light-transmitting substrate 10, the second light-transmitting substrate 20 of the light direction controller 100 transmits visible light. In one example, the second light-transmitting substrate 20 is implemented as a flat glass substrate. The second light-transmitting substrate 20 includes a second light-transmitting electrode 22 on a first main surface 20a. The second light-transmitting electrode 22 is formed over the entire first main surface 20a. The second light-transmitting electrode 22 is formed of ITO. In addition, an insulating layer is disposed on the second light-transmitting electrode 22.

[0079] The second light-transmitting substrate 20 faces the first light-transmitting substrate 10. In this embodiment, the first main surface 10a of the first light-transmitting substrate 10 and the first main surface 20a of the second light-transmitting substrate 20 face each other.

[0080] The first light-transmitting area 32 of the light direction controller 100 is a region that transmits visible light. In this example, the first light-transmitting area 32 is a light-transmitting layer formed of a light-transmitting resin. The first light-transmitting area 32 is disposed on the first main surface 10a of the first light-transmitting substrate 10. In this embodiment, a plurality of first light-transmitting areas 32 are arranged in the X direction at a predetermined spacing. The first light-transmitting area 32 has a rectangular parallelepiped shape, and as shown... Figure 4 As shown, it extends in the Y direction. Additionally, as... Figure 2 As shown, the first light-transmitting area 32 extends from the first light-transmitting substrate 10 toward the second light-transmitting substrate 20, perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and is continuous with the second light-transmitting area 42.

[0081] like Figure 2 and Figure 4As shown, the first light-absorbing region 34 of the light direction controller 100 is located in the area between adjacent first light-transmitting regions 32. Like the first light-transmitting regions 32, the first light-absorbing region 34 extends from the first light-transmitting substrate 10 toward the second light-transmitting substrate 20, perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Details of the first light-absorbing region 34 will be described later.

[0082] Similar to the first light-transmitting area 32, the second light-transmitting area 42 of the light direction controller 100 is a region that transmits visible light. In this example, the second light-transmitting area 42 is a light-transmitting layer formed of a light-transmitting resin. The second light-transmitting area 42 is disposed on the first main surface 20a of the second light-transmitting substrate 20. In this embodiment, a plurality of second light-transmitting areas 42 are arranged in the X direction at the same spacing as the first light-transmitting area 32. The second light-transmitting area 42 has an oblique quadrangular prism shape, and as shown... Figure 4 As shown, it extends in the Y direction. Furthermore, the second light-transmitting region 42 extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10 and is continuous with the first light-transmitting region 32. As... Figure 2 As shown, when observing the cross-section (XZ plane) of the first main surface 10a of the first light-transmitting substrate 10 and the first main surface 20a of the second light-transmitting substrate 20 perpendicular to the first main surface 10a of the first light-transmitting substrate 10, the second light-transmitting region 42 is tilted by an angle θ towards the +X direction relative to the direction perpendicular to the first main surface 10a of the first light-transmitting substrate 10. In this embodiment, the angle θ satisfies tanθ≥D1 / H2, where H2 is the height of the second light-transmitting region 42 in the Z direction, and D1 is the width of the first light-transmitting region 32 and the second light-transmitting region 42 in the X direction.

[0083] The second light-transmitting area 42 is inclined relative to the direction perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and the first light-transmitting area 32 extends perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Therefore, when observing the cross-section (XZ plane) perpendicular to the first main surface 10a of the first light-transmitting substrate 10 and the first main surface 20a of the second light-transmitting substrate 20, as... Figure 2 As shown, the tilt angles of the first light-transmitting area 32 and the second light-transmitting area 42 relative to the first main surface 10a of the first light-transmitting substrate 10 are different. Note that in the example, the ratio of the sum H of the height H1 of the first light-transmitting area 32 in the Z direction and the height H2 of the second light-transmitting area 42 in the Z direction to the width D1 of the first light-transmitting area 32 and the second light-transmitting area 42 in the X direction is 4:1 to 3:1.

[0084] like Figure 2 and Figure 4As shown, the second light-absorbing region 44 of the light direction controller 100 is located in the area between adjacent second light-transmitting regions 42. When observing a cross-section on the XZ plane, the second light-transmitting region 42 is tilted at an angle θ relative to the +Z direction toward the +X direction, and similarly, the second light-absorbing region 44 is also tilted at an angle θ relative to the +Z direction toward the +X direction. Like the second light-transmitting region 42, the second light-absorbing region 44 extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10 and is continuous with the first light-absorbing region 34. Details of the second light-absorbing region 44 will be described later.

[0085] The light-transmitting dispersion medium 52 of the light direction controller 100 is enclosed in the first light-absorbing region 34 and the second light-absorbing region 44. The light-transmitting dispersion medium 52 transmits visible light. The light-transmitting dispersion medium 52 disperses electrophoretic particles 54.

[0086] The electrophoretic particles 54 of the light direction controller 100 are dispersed in a light-transmitting dispersion medium 52 and absorb visible light. The electrophoretic particles 54 carry either a positive or negative charge, and their dispersion state in the light-transmitting dispersion medium 52 changes according to the voltage applied by the first light-transmitting electrode 12 and the second light-transmitting electrode 22. In one example, the electrophoretic particles 54 are implemented as charged carbon black particles. In this embodiment, it is assumed that the electrophoretic particles 54 carry a negative charge.

[0087] Next, the first light-absorbing region 34 and the second light-absorbing region 44 are described.

[0088] The light-transmitting dispersion medium 52 and the electrophoretic particles 54 dispersed in the light-transmitting dispersion medium 52 are enclosed in the first light-absorbing region 34 and the second light-absorbing region 44. Therefore, the first light-absorbing region 34 and the second light-absorbing region 44, together with the first light-transmitting electrode 12 and the second light-transmitting electrode 22, together serve as electrophoretic elements.

[0089] When the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 are equal and no voltage is applied to the electrophoretic particles 54, the electrophoretic particles 54 are uniformly dispersed throughout the first light-absorbing region 34 and the second light-absorbing region 44, and the entire first light-absorbing region 34 and the second light-absorbing region 44 act as a light-absorbing layer. By controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22, the electrophoretic particles 54 can be dispersed only in the first light-absorbing region 34, only in the second light-absorbing region 44, or similarly, and the region corresponding to the dispersion state of the electrophoretic particles 54 can act as a light-absorbing layer. The dispersion state of the electrophoretic particles 54 and the operation of the light direction control element 200 will be described later.

[0090] The voltage controller 110 of the light direction control element 200 controls the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 to control the voltage to be applied to the electrophoretic particles 54. In one example, the voltage controller 110 is implemented as a control circuit including a controller, a power supply circuit, etc.

[0091] Next, the operation of the light direction control element 200 is described. In this description of the operation of the light direction control element 200, it is assumed that a surface light source (uniformly diffused surface light source) 500 with constant brightness regardless of the viewing direction is arranged on the first light-transmitting substrate 10 side of the light direction controller 100. The light direction control element 200 controls the angular distribution of light 510 entering from the -Z direction and emitted in the +Z direction.

[0092] Light blocking mode

[0093] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the electrophoretic particles 54 are uniformly dispersed throughout the first light-absorbing region 34 and the second light-absorbing region 44. Therefore, the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers.

[0094] When observing the cross-section on the XZ plane, the first light-absorbing region 34 is perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and the second light-absorbing region 44 is tilted at an angle θ (tanθ ≥ D1 / H2) relative to the Z direction towards the +X direction. Like this, Figure 5 As shown, the first light-absorbing region 34 and the second light-absorbing region 44, which act as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Furthermore, since the first light-absorbing region 34 and the second light-absorbing region 44 extend in the Y direction, similarly, when observing the cross-section on the YZ plane, the first light-absorbing region 34 and the second light-absorbing region 44, which act as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Therefore, when the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 are equal, the light direction control element 200 blocks the light 510 from the surface light source 500. In the following text, this state is referred to as the "light blocking mode." In the light blocking mode, the light direction control element 200 blocks the emitted light from the display panel 210.

[0095] First diagonal narrow field mode

[0096] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), the negatively charged electrophoretic particles 54 gather in the second light-absorbing region 44 and disperse in the second light-absorbing region 44, such as... Figure 6As shown. Meanwhile, electrophoretic particles 54 are almost non-existent in the first absorption region 34. Therefore, only the second absorption region 44 functions as the light-absorbing layer. In the following text, this state is referred to as the "first diagonal narrow-field mode".

[0097] When observing the cross-section on the XZ plane, the second light-absorbing region 44 and the second light-transmitting region 42 are tilted at an angle θ (tanθ ≥ D1 / H2) relative to the Z direction towards the +X direction. Therefore, in the first diagonal narrow-field mode, in the light 510 entering from the surface light source 500, light with an angle close to θ relative to the Z direction and the +X direction is not absorbed by the second light-absorbing region 44 and is emitted from the light direction controller 100. Furthermore, in the XZ plane, light other than light with an angle close to θ relative to the Z direction and the +X direction is absorbed by the second light-absorbing region 44. Therefore, in a plane parallel to the XZ plane, when the +X direction is 0°, the +Z direction is 90°, and the -X direction is 180°, the emitted light of the light direction control element 200 in the first diagonal narrow-field mode has a narrow-angle distribution close to 90°-θ, as shown below. Figure 7 As shown. Note that in the following embodiments, a similar description is given, wherein the angular distribution of the emitted light from the light direction control element 200 in a plane parallel to the XZ plane is 0° in the +X direction, 90° in the +Z direction, and 180° in the -X direction. The plane parallel to the XZ plane includes the XZ plane itself.

[0098] In this embodiment, the second light-transmitting region 42 and the second light-absorbing region 44, which are tilted at an angle θ (tanθ ≥ D1 / H2) towards the +X direction, extend in the Y direction. Therefore, in a plane parallel to the plane tilted towards the +X direction relative to the YZ plane (0° < tilt angle < 2×θ), the emitted light of the light direction control element 200 in the first diagonal narrow field mode has a uniform angular distribution.

[0099] As described above, in the first diagonal narrow field mode, the emitted light from the light beam control element 200 has a narrow angular distribution of approximately 90°-θ in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to a plane tilted towards the +X direction relative to the YZ plane. Therefore, in the first diagonal narrow field mode, the light beam control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to an angle θ approximately to the right (+X direction) relative to the front surface (+Z direction).

[0100] First Vertical Narrow Field Mode

[0101] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), the negatively charged electrophoretic particles 54 gather in the first light-absorbing region 34 and disperse in the first light-absorbing region 34, such as... Figure 8 As shown. Meanwhile, electrophoretic particles 54 are almost nonexistent in the second absorption region 44. Therefore, only the first absorption region 34 functions as the light-absorbing layer. In the following text, this state is referred to as the "first vertical narrow-field mode".

[0102] When observing the cross-section on the XZ plane, the first light-absorbing region 34 and the first light-transmitting region 32 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the first vertical narrow-field mode of light 510 entering from the surface light source 500, light except for light near the +Z direction is absorbed by the first light-absorbing region 34, such as... Figure 8 As shown. Furthermore, in the XZ plane, among the light 510 entering from the surface light source 500, light approaching the +Z direction is emitted from the ray direction controller 100. Therefore, in a plane parallel to the XZ plane, the emitted light from the ray direction control element 200 in the first vertical narrow-field mode has a narrow angular distribution approaching 90° (+Z direction), as shown. Figure 7 As shown.

[0103] In a plane parallel to the YZ plane, the first light-transmitting region 32 and the first light-absorbing region 34 extend in the Y direction, and thus, the emitted light of the light direction control element 200 in the first vertical narrow field mode has a uniform angular distribution. Note that the plane parallel to the YZ plane includes the YZ plane itself.

[0104] As described above, in the first vertical narrow field mode, the emitted light from the light direction control element 200 has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane. Therefore, in the first vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0105] First wide field mode

[0106] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the first diagonal narrow-field mode (V2 >> V1), negatively charged electrophoretic particles 54 gather on the side of the second light-transmitting electrode 22 in the second light-absorbing region 44, such as... Figure 9 As shown. Therefore, the first light-absorbing region 34 and the second region 44 can hardly function as light-absorbing layers. In the following text, this state is referred to as the "first wide-field mode".

[0107] In the first wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, in a plane parallel to the XZ plane, the emitted light from the light direction control element 200 in the first wide-field mode has a uniform angular distribution, such as... Figure 7 As shown. Furthermore, in a plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the first wide-field mode has a uniform angular distribution. In the first wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300.

[0108] Second wide field mode

[0109] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the first vertical narrow-field mode (V1 >> V2), negatively charged electrophoretic particles 54 gather on the side of the first light-transmitting electrode 12 in the first light-absorbing region 34, such as... Figure 10 As shown. Therefore, the first light-absorbing region 34 and the second light-absorbing region 44 can hardly function as light-absorbing layers. In the following text, this state is referred to as the "second wide-field mode".

[0110] In the second wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the second wide-field mode has a uniform angular distribution, as in the first wide-field mode. In the second wide-field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0111] Therefore, by using the light direction control element 200, light can be emitted in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 (the voltage applied to the electrophoretic particles 54).

[0112] In the light direction control element 200, when transitioning from a light-blocking mode to a first diagonal narrow-field mode, the transition is preferably performed via a first wide-field mode. Furthermore, when transitioning from a light-blocking mode to a first vertical narrow-field mode, the transition is preferably performed via a second wide-field mode. This improves the stable dispersion of electrophoretic particles 54 in the first absorption region 34 or the second absorption region 44, and enhances mode transition reproducibility.

[0113] Next, a specific example of transitioning from the light-blocking mode to the first diagonal narrow field mode is described.

[0114] Voltage controller 110 controls the voltage applied to the electrophoretic particles 54, causing the dispersion state of the electrophoretic particles 54 to change from a dispersion state in which the electrophoretic particles 54 are dispersed in the first light-absorbing region 34 and the second light-absorbing region 44 (light blocking mode) to a dispersion state in which the electrophoretic particles 54 are dispersed in the second light-absorbing region 44 but not in the first light-absorbing region 34 (first diagonal narrow field mode). In light blocking mode, no voltage is applied to the electrophoretic particles 54. In first diagonal narrow field mode, a voltage of a first voltage value (V2>V1) is applied to the electrophoretic particles 54. In this scenario, the voltage controller 110 first applies a second voltage value (V2 >> V1) greater than the first voltage value to the electrophoretic particles 54. This causes the electrophoretic particles 54 to transition from a dispersed state in which they are dispersed in the first light-absorbing region 34 and the second light-absorbing region 44, via a dispersed state in which they are aggregated in the second light-absorbing region 44 (first wide-field mode), to a dispersed state in which they are dispersed in the second light-absorbing region 44 but not in the first light-absorbing region 34. As a result, the electrophoretic particles 54 first aggregate in the second light-absorbing region 44, and then disperse in the second light-absorbing region 44, and thus a stable dispersion state can be formed. Note that the same applies when transitioning from the light-blocking mode to the first vertical narrow-field mode.

[0115] Next, the manufacturing method of the light direction control element 200 is described. Figure 11 This is a flowchart illustrating a method for manufacturing a light direction control element 200. The method for manufacturing the light direction control element 200 includes: forming a first light-transmitting region 32 on a first main surface 10a of a first light-transmitting substrate 10 (step S10); forming a second light-transmitting region 42 on a first main surface 20a of a second light-transmitting substrate 20 (step S20); adhering the first light-transmitting substrate 10 and the second light-transmitting substrate 20 to each other to connect the first light-transmitting region 32 to the second light-transmitting region 42 (step S30); filling with a light-transmitting dispersion medium 52 in which electrophoretic particles 54 are dispersed (step S40); and electrically connecting a voltage controller 110 (step S50).

[0116] In step S10, a first light-transmitting region 32 is formed on the first main surface 10a of the first light-transmitting substrate 10 using a known photolithography technique. A first light-transmitting electrode 12 and an insulating layer are disposed on the first light-transmitting substrate 10. In one example, the first light-transmitting region 32 is formed using a chemically amplifying photoresist known as SU-8 (product name, Nippon Kayaku Co., Ltd.).

[0117] In step S10, in step S20, a second light-transmitting area 42 is formed on the first main surface 20a of the second light-transmitting substrate 20, and a second light-transmitting electrode 22 and an insulating layer are disposed on the second light-transmitting substrate 20.

[0118] In step S30, the first main surface 10a of the first light-transmitting substrate 10 and the first main surface 20a of the second light-transmitting substrate 20 are brought together to face each other, thereby stacking the second light-transmitting substrate 20 on the first light-transmitting substrate 10. In this case, the second light-transmitting substrate 20 can be directly stacked on the first light-transmitting substrate 10, or the first light-transmitting substrate 10 and the second light-transmitting substrate 20 can be adhered to each other by an adhesive. As a result, the first light-transmitting region 32 is connected to the second light-transmitting region 42. The adhesive is a thermosetting adhesive, an ultraviolet (UV) curable adhesive, or the like.

[0119] In step S40, the spacing between adjacent first light-transmitting regions 32 and the spacing between adjacent second light-transmitting regions 42 are filled with a light-transmitting dispersion medium 52, in which electrophoretic particles 54 are dispersed. As a result, a first light-absorbing region 34 and a second light-absorbing region 44 are formed. The first light-absorbing region 34 and the second light-absorbing region 44 are sealed with an adhesive.

[0120] In step S50, the voltage controller 110 is electrically connected to the first light-transmitting electrode 12 and the second light-transmitting electrode 22. Therefore, a light direction control element 200 can be manufactured.

[0121] As described above, when observing the cross-section on the XZ plane, the first light-transmitting area 32 and the second light-transmitting area 42 have different tilt angles relative to the first main surface 10a of the first light-transmitting substrate 10. In this way, the light direction control element 200 can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 (the voltage applied to the electrophoretic particles 54).

[0122] Example 2

[0123] In Embodiment 1, the first light-transmitting region 32 and the first light-absorbing region 34 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. However, when observing the cross-section on the XZ plane, it is possible that the first light-transmitting region 32 and the first light-absorbing region 34 are tilted relative to the direction perpendicular to the first main surface 10a of the first light-transmitting substrate 10 (+Z direction).

[0124] In the light direction control element 200 of this embodiment, the configuration of the first light-transmitting region 32 and the first light-absorbing region 34 differs from that of Embodiment 1. The other configurations of the light direction control element 200 in this embodiment are the same as those in Embodiment 1. Next, the configuration of the first light-transmitting region 32 and the first light-absorbing region 34, as well as the operation of the light direction control element 200, will be described.

[0125] Similar to the first light-transmitting area 32 in Embodiment 1, the first light-transmitting area 32 in this embodiment is a region that transmits visible light. Furthermore, the first light-transmitting area 32 in this embodiment is disposed on the first main surface 10a of the first light-transmitting substrate 10.

[0126] Similar to the second light-transmitting zone 42, as Figure 12 As shown, the first light-transmitting area 32 in this embodiment has the shape of an oblique quadrangular prism and is arranged in the X direction. As... Figure 13 As shown, when observing the cross-section (XZ plane) of the first main surface 10a of the first light-transmitting substrate 10 and the first main surface 20a of the second light-transmitting substrate 20 perpendicular to the first main surface 10a of the first light-transmitting substrate 10, the first light-transmitting area 32 in this embodiment is tilted towards the -X direction relative to the direction perpendicular to the first main surface 10a of the first light-transmitting substrate 10 (+Z direction). In other words, the first light-transmitting area 32 in this embodiment is tilted in the opposite direction to the second light-transmitting area 42 relative to the +Z direction. The other configurations of the first light-transmitting area 32 in this embodiment are the same as those in Embodiment 1.

[0127] Similar to the first light-absorbing region 34 in Embodiment 1, the first light-absorbing region 34 in this embodiment is located in the area between adjacent first light-transmitting regions 32. When observing the cross-section on the XZ plane, the first light-transmitting region 32 is tilted towards the -X direction relative to the +Z direction at an angle. Furthermore, in this embodiment, the first light-absorbing region 34 is also tilted at an angle relative to the +Z direction towards the -X direction. The other configurations of the first light-absorbing region 34 in this embodiment are the same as those in Embodiment 1.

[0128] Next, the operation of the light direction control element 200 of this embodiment will be described. As in Embodiment 1, the operation of the light direction control element 200 of this embodiment will be described assuming that the surface light source 500 is arranged on the side of the first light-transmitting substrate 10 of the light direction controller 100.

[0129] Light blocking mode

[0130] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in Example 1.

[0131] When observing the cross-section on the XZ plane, the first light-absorbing region 34 is tilted towards the -X direction relative to the Z direction at an angle. Furthermore, the second light-absorbing region 44 is tilted at an angle θ (tanθ ≥ D1 / H2) relative to the Z direction towards the +X direction. In this way, similar to the light-blocking mode of Embodiment 1, the first light-absorbing region 34 and the second light-absorbing region 44, acting as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Additionally, since the first light-absorbing region 34 and the second light-absorbing region 44 extend in the Y direction, similarly, when observing the cross-section on the YZ plane, the first light-absorbing region 34 and the second light-absorbing region 44, acting as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Therefore, when the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 are equal, the light direction control element 200 of this embodiment blocks the light 510 from the surface light source 500, just like the light direction control element 200 of Embodiment 1. In other words, the light direction control element 200 blocks the emitted light of the display panel 210.

[0132] Second diagonal narrow field mode

[0133] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "second diagonal narrow field mode".

[0134] The configuration of the second light-absorbing region 44 in this embodiment is the same as that in Embodiment 1. In this way, in the XZ plane of the second diagonal narrow-field mode, light 510 entering from the surface light source 500, having an angle θ close to the Z-direction and +X-direction sides, is emitted from the light direction controller 100. Furthermore, in the XZ plane of the second diagonal narrow-field mode, light other than light having an angle θ close to the Z-direction and +X-direction sides is absorbed by the second light-absorbing region 44. Therefore, in a plane parallel to the XZ plane, the emitted light of the light direction control element 200 in the second diagonal narrow-field mode has a narrow-angle distribution close to 90°-θ, which is the same as the first diagonal narrow-field mode of Embodiment 1. Figure 6 and Figure 7 The same as below.

[0135] The second light-transmitting region 42 and the second light-absorbing region 44, which are tilted at an angle θ (tanθ≥D1 / H2) towards the +X direction, extend in the Y direction. And in this way, in a plane parallel to the plane tilted towards the +X direction relative to the YZ plane (0°<tilt angle<2×θ), the emitted light of the light direction control element 200 in the second diagonal narrow field mode has a uniform angular distribution.

[0136] As described above, in the second diagonal narrow field mode, the emitted light from the light direction control element 200 has a narrow angular distribution of approximately 90°-θ in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to a plane inclined to the +X direction relative to the YZ plane. Therefore, in the second diagonal narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to an angle θ approximately to the right (+X direction) relative to the front surface (+Z direction).

[0137] Third diagonal narrow field mode

[0138] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), the electrophoretic particles 54 aggregate in the first light-absorbing region 34 and disperse in the first light-absorbing region 34, such as... Figure 14 As shown. Meanwhile, electrophoretic particles 54 are almost nonexistent in the second absorption region 44. Therefore, only the first absorption region 34 functions as the absorption layer. In the following text, this state is referred to as the "third diagonal narrow-field mode".

[0139] When observing the cross-section on the XZ plane, the first light-absorbing region 34 and the first light-transmitting region 32 are tilted towards the -X direction relative to the +Z direction at an angle. In this way, in the third diagonal narrow field mode, the light 510 entering from the surface light source 500 has an angle close to the Z-direction and the -X-direction side. The light emitted from the ray direction controller 100 is not absorbed by the first light-absorbing region 34. Furthermore, in the XZ plane, light other than light with an angle close to angle θ relative to the +Z and +X directions is absorbed by the first light-absorbing region 34. Therefore, in a plane parallel to the XZ plane, the emitted light from the ray direction control element 200 in the third diagonal narrow-field mode has a near- Narrow-angle distribution, such as Figure 15 As shown.

[0140] Tilt angle in the -X direction The first light-transmitting region 32 and the first light-absorbing region 34 extend in the Y direction and are inclined in the -X direction parallel to the YZ plane. In the plane of the plane, the emitted light of the light direction control element 200 in the third diagonal narrow field mode has a uniform angular distribution.

[0141] As described above, the emitted light from the ray direction control element 200 in the third diagonal narrow field mode has approximately [missing information - likely a characteristic value] in a plane parallel to the XZ plane. The light direction control element 200 has a narrow angle distribution and a uniform angle distribution in a plane parallel to a plane inclined to the -X direction relative to the YZ plane. Therefore, in the third diagonal narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to an angle close to the left-right direction (-X direction) relative to the front surface (+Z direction).

[0142] Third wide field mode

[0143] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the second diagonal narrow field mode (V2 >> V1), as in the first wide field mode of Embodiment 1, the electrophoretic particles 54 gather on the side of the second light-transmitting electrode 22 of the second light-absorbing region 44 (hereinafter referred to as the "third wide field mode"). Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the third wide field mode has a uniform angular distribution, as in the first wide field mode of Embodiment 1. In the third wide field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0144] Fourth wide field mode

[0145] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the third diagonal narrow-field mode (V1 >> V2), as in the second wide-field mode of Embodiment 1, the electrophoretic particles 54 gather on the side of the first light-transmitting electrode 12 of the first light-absorbing region 34 (hereinafter referred to as the "fourth wide-field mode"). Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the fourth wide-field mode has a uniform angular distribution, as in the second wide-field mode of Embodiment 1. In the fourth wide-field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0146] Therefore, when observing the cross-section on the XZ plane, the tilt angles of the first light-transmitting area 32 and the second light-transmitting area 42 relative to the first main surface 10a of the first light-transmitting substrate 10 will be different. In this way, the light direction control element 200 of this embodiment can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0147] Example 3

[0148] The arrangement of the first light-transmitting area 32 and the second light-transmitting area 42 of the light direction controller 100 in the X and Y directions is possible. In the light direction control element 200 of this embodiment, the arrangement of the first light-transmitting area 32, the first light-absorbing area 34, the second light-transmitting area 42, and the second light-absorbing area 44 differs from that in Embodiment 1. Other configurations of the light direction control element 200 in this embodiment are the same as those in Embodiment 1. Next, the configuration of the first light-transmitting area 32, the first light-absorbing area 34, the second light-transmitting area 42, and the second light-absorbing area 44, as well as the operation of the light direction control element 200, will be described.

[0149] Similar to the first light-transmitting area 32 in Embodiment 1, the first light-transmitting area 32 in this embodiment is a region that transmits visible light. Furthermore, the first light-transmitting area 32 in this embodiment is disposed on the first main surface 10a of the first light-transmitting substrate 10.

[0150] like Figure 16 As shown, the first light-transmitting area 32 in this embodiment has a prism shape and is arranged in a matrix in the X and Y directions. Similar to the first light-transmitting area 32 in Embodiment 1, the first light-transmitting area 32 in this embodiment extends from the first light-transmitting substrate 10 toward the second light-transmitting substrate 20, perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and is continuous with the second light-transmitting area 42. The other configurations of the first light-transmitting area 32 in this embodiment are the same as those in Embodiment 1.

[0151] Similar to the first light-absorbing region 34 in Embodiment 1, the first light-absorbing region 34 in this embodiment is located in the region between adjacent first light-transmitting regions 32. In this embodiment, the first light-transmitting regions 32, which are prism-shaped, are arranged in a matrix, and thus, the first light-absorbing regions 34 form a lattice-shaped region. Like the first light-transmitting region 32 in this embodiment, the first light-absorbing region 34 in this embodiment is perpendicular to the first main surface 10a of the first light-transmitting substrate 10. The other configurations of the first light-absorbing region 34 in this embodiment are the same as those in Embodiment 1.

[0152] Similar to the second light-transmitting region 42 in Embodiment 1, the second light-transmitting region 42 in this embodiment is a region that transmits visible light. The second light-transmitting region 42 in this embodiment has an oblique quadrangular prism shape and is arranged in a matrix in the X and Y directions. The second light-transmitting region 42 in this embodiment extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10 and is continuous with the first light-transmitting region 32. Similar to the second light-transmitting region 42 in Embodiment 1, when observing a cross-section on the XZ plane, the second light-transmitting region 42 in this embodiment is tilted at an angle θ (tanθ ≥ D1 / H2) relative to the Z direction toward the +X direction. Other configurations of the second light-transmitting region 42 in this embodiment are the same as those of the second light-transmitting region 42 in Embodiment 1.

[0153] Similar to the second light-absorbing region 44 in Embodiment 1, the second light-absorbing region 44 in this embodiment is located in the region between adjacent second light-transmitting regions 42. In this embodiment, the oblique quadrangular prism-shaped second light-transmitting regions 42 are arranged in a matrix, and thus, the second light-absorbing region 44 in this embodiment forms a lattice-shaped region, wherein the X-direction side surface is tilted at an angle θ towards the +X-direction side. The other configurations of the second light-absorbing region 44 in this embodiment are the same as those in Embodiment 1.

[0154] Next, the operation of the light direction control element 200 of this embodiment will be described. As in Embodiment 1, the operation of the light direction control element 200 of this embodiment will be described assuming that the surface light source 500 is arranged on the first light-transmitting substrate 10 side of the light direction controller 100. Note that in the following embodiments, the operation of the light direction control element 200 will be described assuming that the surface light source 500 is arranged on the first light-transmitting substrate 10 side of the light direction controller 100.

[0155] Light blocking mode

[0156] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in Example 1.

[0157] When observing the cross-section on the XZ plane, similar to the light-blocking mode in Embodiment 1, the first light-absorbing region 34 and the second light-absorbing region 44, acting as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Similarly, when observing the cross-section on the YZ plane, the first light-absorbing region 34 and the second light-absorbing region 44, acting as light-absorbing layers, absorb all the light 510 entering from the surface light source 500. Therefore, when the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 are equal, the light direction control element 200 of this embodiment blocks the light 510 from the surface light source 500, similar to the light direction control element 200 in Embodiment 1. In other words, the light direction control element 200 blocks the emitted light from the display panel 210.

[0158] Fourth diagonal narrow field mode

[0159] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "fourth diagonal narrow field mode".

[0160] When observing a cross-section on a plane parallel to the XZ plane, including the second light-transmitting region 42, the second light-absorbing region 44 and the second light-transmitting region 42 are tilted at an angle θ (tanθ ≥ D1 / H2) relative to the Z direction towards the +X direction. Therefore, in the plane parallel to the XZ plane, including the second light-transmitting region 42, the emitted light of the light direction control element 200 in the fourth diagonal narrow-field mode has a narrow-angle distribution close to 90°-θ, which is the same as in the first diagonal narrow-field mode of Embodiment 1. Meanwhile, when observing a cross-section on a plane parallel to the XZ plane, including the lattice portion of the second light-absorbing region 44, the second light-absorbing region 44 extends in the X direction, and thus, in the fourth diagonal narrow-field mode, the light 510 entering from the surface light source 500 is absorbed by the second light-absorbing region 44.

[0161] When observing a cross-section on a plane parallel to a plane tilted to the +X direction relative to the YZ plane (0° < tilt angle < 2×θ), the second light-absorbing region 44 and the second light-transmitting region 42 are alternately arranged in the Y direction. Therefore, in the plane parallel to the plane tilted to the +X direction relative to the YZ plane (0° < tilt angle < 2×θ), the emitted light of the light direction control element 200 in the fourth diagonal narrow-field mode has a narrow-angle distribution.

[0162] As described above, the emitted light from the light direction control element 200 in the fourth diagonal narrow field mode has a narrow angular distribution of approximately 90°-θ in a plane parallel to the XZ plane, including the second light-transmitting area 42, and also has a narrow angular distribution in a plane parallel to a plane inclined to the +X direction relative to the YZ plane. Therefore, in the fourth diagonal narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to an angle θ approximately to the right (+X direction) relative to the front surface (+Z direction). Furthermore, the light direction control element 200 can reduce the viewing angle of the display device 300 in the vertical direction (Y direction).

[0163] Second vertical narrow field mode

[0164] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), only the first light-absorbing region 34 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "second vertical narrow field mode".

[0165] When observing a cross-section on a plane parallel to the XZ plane, including the first light-transmitting region 32, the first light-absorbing region 34 and the first light-transmitting region 32 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Therefore, in the plane parallel to the XZ plane, including the first light-transmitting region 32, the emitted light of the light direction control element 200 in the second vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction), which is similar to the first vertical narrow field mode in Embodiment 1. Figure 7 and Figure 8 The same applies. At the same time, when observing a cross-section on a plane parallel to the XZ plane, including the lattice portion of the first light-absorbing region 34, the first light-absorbing region 34 extends in the X direction, and in this way, in the second vertical narrow field mode, the light 510 entering from the surface light source 500 is absorbed by the first light-absorbing region 34.

[0166] When observing a cross-section on a plane parallel to the YZ plane, including the first light-transmitting region 32, the first light-absorbing region 34 and the first light-transmitting region 32 in this embodiment are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the second vertical narrow-field mode of light 510 entering from the surface light source 500, light other than light near the +Z direction is absorbed by the first light-absorbing region 34, such as... Figure 17 As shown. Furthermore, in the light 510 entering from the surface light source 500, light approaching the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the YZ plane, when the +Y direction is 0°, the +Z direction is 90°, and the -Y direction is 180°, in a plane parallel to the YZ plane including the first light-transmitting region 32, the emitted light from the light direction control element 200 in the second vertical narrow-field mode has a narrow-angle distribution approaching 90° (+Z direction), as shown. Figure 18 As shown. Simultaneously, when observing a cross-section on a plane parallel to the YZ plane, including the lattice portion of the first light-absorbing region 34, the first light-absorbing region 34 extends in the Y direction, and thus, in the second vertical narrow-field mode, light 510 entering from the surface light source 500 is absorbed by the first light-absorbing region 34. Note that in the following embodiments, a description is given in which the angular distribution of the emitted light from the light direction control element 200 in a plane parallel to the YZ plane (vertical direction) is 0° in the +Y direction, 90° in the +Z direction, and 180° in the -Y direction.

[0167] As described above, the emitted light from the light direction control element 200 in the second vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane including the first light-transmitting area 32, and also has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the YZ plane including the first light-transmitting area 32. Therefore, in the second vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 to near the front surface (+Z direction).

[0168] Fifth wide field mode

[0169] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the fourth diagonal narrow field mode (V2 >> V1), as in the first wide field mode of Embodiment 1, the electrophoretic particles 54 gather on the side of the second light-transmitting electrode 22 of the second light-absorbing region 44 (hereinafter referred to as the "fifth wide field mode"). Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the fifth wide field mode has a uniform angular distribution, as in the first wide field mode of Embodiment 1. In the fifth wide field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0170] Sixth wide field mode

[0171] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the second vertical narrow field mode (V1 >> V2), as in the second wide field mode of Embodiment 1, the electrophoretic particles 54 gather on the side of the first light-transmitting electrode 12 of the first light-absorbing region 34 (hereinafter referred to as the "sixth wide field mode"). Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the sixth wide field mode has a uniform angular distribution, as in the second wide field mode of Embodiment 1. In the sixth wide field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0172] Therefore, similar to the light direction control element 200 in Embodiments 1 and 2, the light direction control element 200 in this embodiment can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0173] Example 4

[0174] When observing a cross-section in the XZ plane, a configuration in which the shape of the first light-transmitting region 32 and the shape of the second light-transmitting region 42 are different is possible. In the case of the light-direction control element 200 of the present embodiment, the configurations of the second light-transmitting region 42 and the second light-absorbing region 44 are different from those in the first embodiment. Other configurations of the light-direction control element 200 of the present embodiment are the same as those of the light-direction control element 200 of the first embodiment. Next, the configurations of the second light-transmitting region 42 and the second light-absorbing region 44, and the operation of the light-direction control element 200 are described.

[0175] Similar to the second light-transmitting region 42 of the first embodiment, the second light-transmitting region 42 of the present embodiment is a region that transmits visible light. The second light-transmitting region 42 of the present embodiment is provided on the first main surface 20a of the second light-transmitting substrate 20.

[0176] As Figure 19 and Figure 20 shown, the second light-transmitting region 42 of the present embodiment has the shape of a rectangular parallelepiped extending in the Y direction and is arranged at a predetermined pitch in the X direction. The width D2 of the second light-transmitting region 42 of the present embodiment in the X direction is narrower (D2 < D1) than the width D1 of the first light-transmitting region 32 of the present embodiment (the widths D1 of the first light-transmitting region 32 and the second light-transmitting region 42 of the first embodiment) in the X direction. Therefore, when observing a cross-section in the XZ plane, the shape of the first light-transmitting region 32 and the shape of the second light-transmitting region 42 are different.

[0177] The second light-transmitting region 42 of the present embodiment extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10, perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and is continuous with the first light-transmitting region 32. Other configurations of the second light-transmitting region 42 of the present embodiment are the same as those of the second light-transmitting region 42 of the first embodiment.

[0178] Similar to the second light-absorbing region 44 of the first embodiment, the second light-absorbing region 44 of the present embodiment is the region between adjacent second light-transmitting regions 42. Similar to the second light-transmitting region 42, the second light-absorbing region 44 of the present embodiment extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10, perpendicular to the first main surface 10a of the first light-transmitting substrate 10. In addition, the second light-absorbing region 44 of the present embodiment extends in the Y direction. In the present embodiment, the width D2 of the second light-transmitting region 42 in the X direction is narrower than the width D1 of the first light-transmitting region 32 in the X direction, and thus, the width of the second light-absorbing region 44 of the present embodiment in the X direction is wider than the width of the first light-absorbing region 34 in the X direction. Other configurations of the second light-absorbing region 44 of the present embodiment are the same as those of the second light-absorbing region 44 of the first embodiment.

[0179] Next, the operation of the light-direction control element 200 of the present embodiment is described.

[0180] Third Vertical Narrow Field Mode

[0181] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in Example 1. In the following text, this state is referred to as the "third vertical narrow field mode".

[0182] When observing the cross-section on the XZ plane, the first light-absorbing region 34 and the second light-absorbing region 44 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the third vertical narrow-field mode, in the light 510 entering from the surface light source 500, light other than light near the +Z direction is absorbed by the first light-absorbing region 34 and the second light-absorbing region 44, as shown below. Figure 21 As shown. Furthermore, in the XZ plane, among the light 510 entering from the surface light source 500, light approaching the +Z direction is emitted from the ray direction controller 100. Therefore, in a plane parallel to the XZ plane, the emitted light from the ray direction control element 200 in the third vertical narrow field mode has a narrow angular distribution approaching 90° (+Z direction), as shown. Figure 22 As shown. In this embodiment, the width D2 of the second light-transmitting region 42 in the X direction is narrower than the width D1 of the first light-transmitting region 32 and the second light-transmitting region 42 in the X direction in Embodiment 1. Thus, the angular distribution of emitted light in the third vertical narrow-field mode is narrower than the angular distribution of emitted light in the first vertical narrow-field mode of Embodiment 1, and the transmittance in the third vertical narrow-field mode is lower than the transmittance in the first vertical narrow-field mode.

[0183] Therefore, in a plane parallel to the YZ plane, including the first light-transmitting area 32 and the second light-transmitting area 42, the first light-transmitting area 32 and the second light-transmitting area 42 extend in the Y direction, and thus, the emitted light of the light direction control element 200 in the third vertical narrow field mode has a uniform angular distribution. In another plane parallel to the YZ plane, the first light-absorbing area 34 and the second light-absorbing area 44 extend in the Y direction, and thus, the light 510 entering from the surface light source 500 is absorbed by the first light-absorbing area 34 and the second light-absorbing area 44.

[0184] As described above, the emitted light from the light direction control element 200 in the third vertical narrow field mode has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane, which includes the first light-transmitting area 32 and the second light-transmitting area 42. Therefore, in the third vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0185] Fourth vertical narrow field mode

[0186] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "fourth vertical narrow field mode".

[0187] When observing the cross-section on the XZ plane, the second light-absorbing region 44 and the second light-transmitting region 42 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the fourth vertical narrow-field mode, in the light 510 entering from the surface light source 500, light except for light near the +Z direction is absorbed by the second light-absorbing region 44, as in the third vertical narrow-field mode. Furthermore, on the XZ plane, in the light 510 entering from the surface light source 500, light near the +Z direction is emitted from the light direction controller 100.

[0188] In a plane parallel to the YZ plane, including the second light-transmitting region 42, the second light-transmitting region 42 extends in the Y direction, and thus, the emitted light from the light direction control element 200 in the fourth vertical narrow-field mode has a uniform angular distribution. In another plane parallel to the YZ plane, the second light-absorbing region 44 extends in the Y direction, and thus, the light 510 entering from the surface light source 500 is absorbed by the second light-absorbing region 44. Therefore, in the fourth vertical narrow-field mode, light with the same angular distribution as in the third vertical narrow-field mode exits from the light direction control element 200.

[0189] As described above, in the fourth vertical narrow field mode, light with the same angular distribution as in the third vertical narrow field mode is emitted from the light direction control element 200. Therefore, in the fourth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0190] Fifth vertical narrow field mode

[0191] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), only the first light-absorbing region 34 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "fifth vertical narrow field mode".

[0192] When observing the cross-section on the XZ plane, the first light-absorbing region 34 and the first light-transmitting region 32 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the fifth vertical narrow-field mode, in the light 510 entering from the surface light source 500, light other than light near the +Z direction is absorbed by the first light-absorbing region 34. Furthermore, on the XZ plane, in the light 510 entering from the surface light source 500, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the XZ plane, the emitted light of the light direction control element 200 in the fifth vertical narrow-field mode has a narrow angle distribution of approximately 90° (+Z direction), as shown below. Figure 22 As shown.

[0193] In a plane parallel to the YZ plane including the first light-transmitting region 32, the first light-transmitting region 32 extends in the Y direction. Therefore, in a plane parallel to the YZ plane including the first light-transmitting region 32, the emitted light of the light direction control element 200 in the fifth vertical narrow field mode has a uniform angular distribution. Simultaneously, in a plane parallel to the YZ plane including the first light-absorbing region 34, the first light-absorbing region 34 extends in the Y direction, and thus, in the fifth vertical narrow field mode, the light 510 entering from the surface light source 500 is absorbed by the first light-absorbing region 34.

[0194] In this embodiment, the width D1 of the first light-transmitting region 32 in the X direction is wider than the width D2 of the second light-transmitting region 42 in the X direction. Furthermore, the angular distribution of emitted light in the fifth vertical narrow-field mode is wider than that in the third and fourth vertical narrow-field modes. Additionally, the transmittance in the fifth vertical narrow-field mode is higher than that in the third and fourth vertical narrow-field modes.

[0195] As described above, the emitted light from the light direction control element 200 in the fifth vertical narrow field mode has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane, including the first light-transmitting area 32. Therefore, in the fifth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0196] Seventh wide field mode

[0197] When the voltage controller 110 executes control such that the potential V2 of the second transparent electrode 22 is greater than the potential V1 of the first transparent electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the fourth vertical narrow field mode (V2 >> V1), as in Embodiment 1, the electrophoretic particles 54 aggregate on the side of the second transparent electrode 22 of the second light-absorbing region 44, and the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as a light-absorbing layer. In the following text, this state is referred to as the "seventh wide field mode".

[0198] In the seventh wide-field mode, the first absorption region 34 and the second absorption region 44 hardly function as absorption layers. Therefore, in a plane parallel to the XZ plane, the emitted light from the light direction control element 200 in the seventh wide-field mode has a uniform angular distribution, such as... Figure 22 As shown. In this embodiment, the width D2 of the second light-transmitting area 42 in the X direction is narrower than the width D1 of the first light-transmitting area 32 and the second light-transmitting area 42 in the X direction in Embodiment 1, and thus, the transmittance in the seventh wide-field mode is lower than that in the first wide-field mode. Furthermore, in a plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the seventh wide-field mode has a uniform angular distribution. In the seventh wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300.

[0199] Eighth wide field mode

[0200] When the voltage controller 110 executes control such that the potential V1 of the first transparent electrode 12 is greater than the potential V2 of the second transparent electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the fifth vertical narrow field mode (V1>>V2), as in Embodiment 1, the electrophoretic particles 54 aggregate on the side of the first transparent electrode 12 of the first light-absorbing region 34, and the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. In the following text, this state is referred to as the "eighth wide field mode".

[0201] In the eighth wide-field mode, the first absorption region 34 and the second absorption region 44 hardly function as light-absorbing layers. Therefore, in a plane parallel to the XZ plane, the emitted light from the light direction control element 200 in the eighth wide-field mode has a uniform angular distribution, such as... Figure 22 As shown. Furthermore, in a plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the eighth wide-field mode has a uniform angular distribution. In the eighth wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300.

[0202] In this embodiment, the width D1 of the first light-transmitting area 32 in the X direction is wider than the width D2 of the second light-transmitting area 42 in the X direction, and thus, the transmittance in the eighth wide-field mode is higher than the transmittance in the seventh wide-field mode.

[0203] As described above, when observing the cross-section on the XZ plane, the shape of the first light-transmitting area 32 is different from the shape of the second light-transmitting area 42. In this way, the light direction control element 200 of this embodiment can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0204] Example 5

[0205] In Embodiment 4, the second light-transmitting areas 42 are arranged in the X direction, but a matrix arrangement of the second light-transmitting areas 42 is possible. In the case of the light direction control element 200 of this embodiment, the arrangement of the second light-transmitting areas 42 and the second light-absorbing areas 44 differs from that in Embodiment 4. Other configurations of the light direction control element 200 in this embodiment are the same as those in Embodiment 4. Next, the configuration of the second light-transmitting areas 42 and the second light-absorbing areas 44, and the operation of the light direction control element 200, will be described.

[0206] Similar to the second light-transmitting area 42 in Embodiment 4, the second light-transmitting area 42 in this embodiment is a region that transmits visible light. The second light-transmitting area 42 in this embodiment is disposed on the first main surface 20a of the second light-transmitting substrate 20.

[0207] like Figure 23 As shown, the second light-transmitting area 42 in this embodiment has a prism shape and is arranged in a matrix in the X and Y directions. The width D2 of the second light-transmitting area 42 in the X direction is narrower than the width D1 of the first light-transmitting area 32 in the X direction (the widths D1 of the first light-transmitting area 32 and the second light-transmitting area 42 in the X direction in Embodiment 1). The second light-transmitting area 42 in this embodiment extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10, perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and is continuous with the first light-transmitting area 32. In this embodiment, like the first light-transmitting area 32 in Embodiment 4, the first light-transmitting area 32 has a rectangular parallelepiped extending in the Y direction, and the second light-transmitting area 42 and the first light-transmitting area 32 are configured such that a plurality of second light-transmitting areas 42 are arranged along the Y direction (a predetermined first direction) on a first light-transmitting area 32. The other configurations of the second light-transmitting area 42 in this embodiment are the same as those of the second light-transmitting area 42 in Embodiment 4.

[0208] Similar to the second light-absorbing region 44 in Embodiment 4, the second light-absorbing region 44 in this embodiment is located in the region between adjacent second light-transmitting regions 42. In this embodiment, the prism-shaped second light-transmitting regions 42 are arranged in a matrix, and thus, the second light-absorbing regions 44 form a lattice-shaped region. The second light-absorbing region 44 in this embodiment is perpendicular to the first main surface 10a of the first light-transmitting substrate 10. The other configurations of the second light-absorbing region 44 in this embodiment are the same as those in Embodiment 4.

[0209] Next, the operation of the light direction control element 200 in this embodiment will be described.

[0210] Sixth Vertical Narrow Field Mode

[0211] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in Example 1. In the following text, this state is referred to as the "sixth vertical narrow field mode".

[0212] When observing a cross-section on a plane parallel to the XZ plane, including the first light-transmitting region 32 and the second light-transmitting region 42, the first light-absorbing region 34 and the second light-absorbing region 44 are perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the sixth vertical narrow field mode, as in the third vertical narrow field mode of Embodiment 4 (… Figure 21 As shown below, in the light 510 entering from the surface light source 500, light except for light near the +Z direction is absorbed by the first light-absorbing region 34 and the second light-absorbing region 44. Additionally, in the light 510 entering from the surface light source 500, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the XZ plane including the first light-transmitting region 32 and the second light-transmitting region 42, the emitted light of the light direction control element 200 in the sixth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction), which is the same as in the third vertical narrow field mode. Simultaneously, when observing a cross-section on a plane parallel to the XZ plane including the first light-transmitting region 32 and the second light-absorbing region 44, the second light-absorbing region 44 extends in the X direction, and thus, the light 510 entering from the surface light source 500 is absorbed by the second light-absorbing region 44.

[0213] In this embodiment, the width D2 of the second light-transmitting region 42 in the X direction is narrower than the width D1 of the first light-transmitting region 32 and the second light-transmitting region 42 in the X direction in Embodiment 1. Furthermore, as in the third vertical narrow-field mode, the angular distribution of emitted light in the sixth vertical narrow-field mode is narrower than the angular distribution of emitted light in the first vertical narrow-field mode of Embodiment 1. Additionally, the transmittance in the sixth vertical narrow-field mode is lower than the transmittance in the first vertical narrow-field mode.

[0214] When observing a cross-section on a plane parallel to the YZ plane, including the first light-transmitting region 32 and the second light-transmitting region 42, the second light-transmitting region 42 has a prism shape. Thus, in the sixth vertical narrow-field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32, and in the light transmitted through the first light-transmitting region 32, light other than light near the +Z direction is absorbed by the second light-absorbing region 44, as shown... Figure 24 As shown. Furthermore, in the light transmitted through the first light-transmitting region 32, light approaching the +Z direction is emitted from the light direction controller 100. Therefore, as... Figure 25 As shown, in a plane parallel to the YZ plane including the first light-transmitting region 32 and the second light-transmitting region 42, the emitted light of the light direction control element 200 in the sixth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction). Meanwhile, when observing a cross-section on a plane parallel to the YZ plane including the second light-absorbing region 44, the second light-absorbing region 44 extends in the Y direction, and thus, the light 510 entering from the surface light source 500 is absorbed by the second light-absorbing region 44.

[0215] As described above, the emitted light from the light direction control element 200 in the sixth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane including the first light-transmitting area 32 and the second light-transmitting area 42, and also has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the YZ plane including the first light-transmitting area 32 and the second light-transmitting area 42. Therefore, in the sixth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 to near the front surface (+Z direction).

[0216] Seventh Vertical Narrow Field Mode

[0217] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "seventh vertical narrow field mode".

[0218] When observing a cross-section on a plane parallel to the XZ plane, including the first light-transmitting region 32 and the second light-transmitting region 42, the second light-absorbing region 44 is perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the seventh vertical narrow-field mode, in the light 510 entering from the surface light source 500, light except for light approaching the +Z direction is absorbed by the second light-absorbing region 44, as in the sixth vertical narrow-field mode. Furthermore, in the light 510 entering from the surface light source 500, light approaching the +Z direction is emitted from the light direction controller 100. Similarly, in a plane parallel to the YZ plane, including the first light-transmitting region 32 and the second light-transmitting region 42, light approaching the +Z direction is emitted from the light direction controller 100, as in the sixth vertical narrow-field mode. Therefore, in the seventh vertical narrow-field mode, light with the same angular distribution as in the sixth vertical narrow-field mode is emitted from the light direction control element 200.

[0219] As described above, in the seventh vertical narrow field mode, light with the same angular distribution as in the sixth vertical narrow field mode is emitted from the light direction control element 200. Therefore, in the seventh vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 to near the front surface (+Z direction), as in the sixth vertical narrow field mode.

[0220] Eighth Vertical Narrow Field Mode

[0221] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), only the first light-absorbing region 34 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "eighth vertical narrow field mode".

[0222] In this embodiment, the first light-transmitting area 32 and the first light-absorbing area 34 have the same shape as those in Embodiment 4. Therefore, in the eighth vertical narrow field mode, light with the same angular distribution as in the fifth vertical narrow field mode of Embodiment 4 is emitted from the light direction control element 200. Furthermore, in the eighth vertical narrow field mode, the light direction control element 200 can restrict the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction), as in the fifth vertical narrow field mode.

[0223] Ninth Wide Field Mode

[0224] When the voltage controller 110 executes control such that the potential V2 of the second transparent electrode 22 is greater than the potential V1 of the first transparent electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the seventh vertical narrow field mode (V2 >> V1), as in Embodiment 1, the electrophoretic particles 54 aggregate on the side of the second transparent electrode 22 of the second light-absorbing region 44, and the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. In the following text, this state is referred to as the "ninth wide field mode".

[0225] In the ninth wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, the emitted light from the light direction control element 200 in the ninth wide-field mode has a uniform angular distribution in both the plane parallel to the XZ plane and the plane parallel to the YZ plane. In the ninth wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300. In this embodiment, the width D2 of the second light-transmitting region 42 in the X direction is narrower than the width D1 of the first light-transmitting region 32 in the X direction in Embodiment 1, and the second light-absorbing region 44 has a lattice shape. Thus, the transmittance in the ninth wide-field mode is lower than that in the first wide-field mode.

[0226] Tenth wide field mode

[0227] When the voltage controller 110 executes control such that the potential V1 of the first transparent electrode 12 is greater than the potential V2 of the second transparent electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the eighth vertical narrow field mode (V1>>V2), as in Embodiment 1, the electrophoretic particles 54 aggregate on the side of the first transparent electrode 12 of the first light-absorbing region 34, and the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. In the following text, this state is referred to as the "tenth wide field mode".

[0228] In the tenth wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, the emitted light from the light direction control element 200 in the tenth wide-field mode has a uniform angular distribution in both the plane parallel to the XZ plane and the plane parallel to the YZ plane. In the tenth wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300. In this embodiment, the width D1 of the first light-transmitting region 32 in the X direction is wider than the width D2 of the second light-transmitting region 42 in the X direction, and thus, the transmittance in the tenth wide-field mode is higher than that in the ninth wide-field mode.

[0229] Therefore, similar to the light direction control element 200 in Embodiment 4, the light direction control element 200 in this embodiment can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0230] Example 6

[0231] In Embodiment 4, the first light-transmitting area 32 and the second light-transmitting area 42 have the shape of a rectangular parallelepiped extending in the Y direction. However, it is possible for the first light-transmitting area 32 and the second light-transmitting area 42 to have a rectangular parallelepiped shape extending in different directions. In the case of the light direction control element 200 of this embodiment, the configuration of the second light-transmitting area 42 and the second light-absorbing area 44 is different from that in Embodiment 4. The other configurations of the light direction control element 200 of this embodiment are the same as those of the light direction control element 200 of Embodiment 4. Next, the configuration of the second light-transmitting area 42 and the second light-absorbing area 44, as well as the operation of the light direction control element 200, will be described.

[0232] Similar to the second light-transmitting area 42 in Embodiment 4, the second light-transmitting area 42 in this embodiment is a region that transmits visible light. The second light-transmitting area 42 in this embodiment is disposed on the first main surface 20a of the second light-transmitting substrate 20. For example... Figure 26 As shown, the second light-transmitting area 42 in this embodiment has the shape of a rectangular parallelepiped extending in the X direction and is arranged at a predetermined interval in the Y direction. Therefore, when observing the cross-section on the XZ plane, the shapes of the first light-transmitting area 32 and the second light-transmitting area 42 are different.

[0233] In this embodiment, the second light-transmitting region 42 extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10, perpendicular to the first main surface 10a of the first light-transmitting substrate 10, and is continuous with the first light-transmitting region 32. The other configurations of the second light-transmitting region 42 in this embodiment are the same as those in Embodiment 4.

[0234] Similar to the second light-absorbing region 44 in Embodiment 4, the second light-absorbing region 44 in this embodiment is located in the region between adjacent second light-transmitting regions 42. In this embodiment, the second light-absorbing region 44 extends in the X direction, the same as the second light-transmitting region 42. Furthermore, like the second light-transmitting region 42, the second light-absorbing region 44 extends from the second light-transmitting substrate 20 toward the first light-transmitting substrate 10, perpendicular to the first main surface 10a of the first light-transmitting substrate 10. The other configurations of the second light-absorbing region 44 in this embodiment are the same as those in Embodiment 4.

[0235] Next, the operation of the light direction control element 200 in this embodiment will be described.

[0236] Ninth Vertical Narrow Field Mode

[0237] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in Example 1. In the following text, this state is referred to as the "ninth vertical narrow field mode".

[0238] When observing a cross-section on a plane parallel to the XZ plane, including the first light-transmitting region 32 and the second light-transmitting region 42, the first light-absorbing region 34 is perpendicular to the first main surface 10a of the first light-transmitting substrate 10. Thus, in the ninth vertical narrow-field mode, in the light 510 entering from the surface light source 500, light other than light near the +Z direction is absorbed by the first light-absorbing region 34, such as... Figure 27 As shown. Additionally, the incoming light 510 passes through the surface light source 500, with light in the near +Z direction passing through the first light-transmitting area 32. The light transmitted through the first light-transmitting area 32 passes through the second light-transmitting area 42 and exits from the light direction controller 100. Therefore, in a plane parallel to the XZ plane including the first and second light-transmitting areas 32, the emitted light from the light direction control element 200 in the ninth vertical narrow-field mode has a narrow-angle distribution of approximately 90° (in the +Z direction), as... Figure 28 As shown. At the same time, when observing the cross-section on a plane parallel to the XZ plane, including the first light-transmitting area 32 and the second light-absorbing area 44, in the ninth vertical narrow field mode, the second light-absorbing area 44 extends in the X direction, and light 510 entering from the surface light source 500 is absorbed by the second light-absorbing area 44.

[0239] In this embodiment, the second light-absorbing region 44 extending in the X direction absorbs a portion of the light transmitted through the first light-absorbing region 34, and thus, the transmittance in the ninth vertical narrow field mode is low.

[0240] When observing a cross-section on a plane parallel to the YZ plane, including the first light-transmitting area 32 and the second light-transmitting area 42, the sixth vertical narrow field mode of Example 5 ( Figure 24 Similarly, in the ninth vertical narrow field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32, and in the light transmitted through the first light-transmitting region 32, light other than light near the +Z direction is absorbed by the second light-absorbing region 44. In the light transmitted through the first light-transmitting region 32, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the YZ plane including the first light-transmitting region 32 and the second light-transmitting region 42, the emitted light of the light direction control element 200 in the ninth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction), such as... Figure 29As shown. At the same time, when observing the cross-section on a plane parallel to the YZ plane including the first light-absorbing region 34 and the second light-transmitting region 42, in the ninth vertical narrow field mode, the first light-absorbing region 34 extends in the Y direction, and light 510 entering from the surface light source 500 is absorbed by the first light-absorbing region 34.

[0241] As described above, the emitted light from the light direction control element 200 in the ninth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane including the first light-transmitting area 32 and the second light-transmitting area 42, and also has a narrow angle distribution of approximately 90° (+Z direction) in a plane parallel to the YZ plane including the first light-transmitting area 32 and the second light-transmitting area 42. Therefore, in the ninth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 to near the front surface (+Z direction).

[0242] Tenth Vertical Narrow Field Mode

[0243] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "tenth vertical narrow field mode".

[0244] When observing a cross-section on a plane parallel to the XZ plane, including the second absorption region 44, such as Figure 30 As shown, in the tenth vertical narrow field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, and then absorbed by the second light-absorbing region 44 extending in the X direction. Simultaneously, when observing a cross-section on a plane parallel to the XZ plane including the second light-transmitting region 42, as... Figure 31 As shown, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, and then transmitted through the second light-transmitting region 42. Therefore, in a plane parallel to the XZ plane including the second light-transmitting region 42, the emitted light of the light direction control element 200 in the tenth vertical narrow field mode has a uniform angular distribution, such as... Figure 28 As shown.

[0245] When observing the cross-section on the YZ plane, in the tenth vertical narrow field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32 and the first light-absorbing region 34. Of the light transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, light other than that near the +Z direction is absorbed by the second light-absorbing region 44. Of the light transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the tenth vertical narrow field mode has a narrow angular distribution of approximately 90° (+Z direction), as shown below. Figure 29 As shown.

[0246] Since the light 510 entering from the surface light source 500 is not absorbed by the first light-absorbing region 34, the transmittance in the tenth vertical narrow field mode is higher than that in the ninth vertical narrow field mode.

[0247] As described above, the emitted light from the light direction control element 200 in the tenth vertical narrow field mode has a uniform angular distribution in a plane parallel to the XZ plane, including the second light-transmitting area 42, and a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the YZ plane. Therefore, in the tenth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the vertical direction (Y direction) to be close to the front surface (+Z direction).

[0248] Eleventh Vertical Narrow Field Mode

[0249] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), only the first light-absorbing region 34 acts as a light-absorbing layer, as in Example 1. In the following text, this state is referred to as the "eleventh vertical narrow field mode".

[0250] In this embodiment, the first light-transmitting region 32 and the first light-absorbing region 34 have the same shape as those in Embodiment 4. When observing the cross-section on the XZ plane, in the eleventh vertical narrow-field mode of the light 510 entering from the surface light source 500, light other than light near the +Z direction is absorbed by the second light-absorbing region 44, as in the fifth vertical narrow-field mode of Embodiment 4. Furthermore, in the light 510 entering from the surface light source 500, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the XZ plane, the emitted light of the light direction control element 200 in the eleventh vertical narrow-field mode has the same narrow-angle distribution of approximately 90° (+Z direction) as in the fifth vertical narrow-field mode, as... Figure 28As shown. Furthermore, in a plane parallel to the YZ plane, the emitted light from the ray direction control element 200 in the eleventh vertical narrow-field mode has the same uniform angular distribution as in the fifth vertical narrow-field mode, such as... Figure 29 As shown.

[0251] Since the light 510 entering from the surface light source 500 is not absorbed by the second light-absorbing region 44, the transmittance in the eleventh vertical narrow field mode is higher than that in the ninth vertical narrow field mode.

[0252] As described above, in the eleventh vertical narrow field mode, the emitted light from the light direction control element 200 has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane. Therefore, in the eleventh vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0253] Eleventh Wide Field Mode

[0254] When the voltage controller 110 executes control such that the potential V2 of the second transparent electrode 22 is greater than the potential V1 of the first transparent electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the tenth vertical narrow field mode (V2 >> V1), as in Embodiment 1, the first light-absorbing region 34 and the second light-absorbing region 44 can hardly function as light-absorbing layers. In the following text, this state is referred to as the "eleventh wide field mode".

[0255] In the eleventh wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the eleventh wide-field mode has a uniform angular distribution. In the eleventh wide-field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0256] Twelfth Wide Field Mode

[0257] When the voltage controller 110 executes control such that the potential V1 of the first transparent electrode 12 is greater than the potential V2 of the second transparent electrode 22, and the difference between potential V1 and potential V2 is greater than the eleventh vertical narrow field mode (V1>>V2), as in Embodiment 1, the first light-absorbing region 34 and the second light-absorbing region 44 can hardly function as light-absorbing layers. In the following text, this state is referred to as the "twelfth wide field mode".

[0258] In the twelfth wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the twelfth wide-field mode has a uniform angular distribution. In the twelfth wide-field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0259] Therefore, similar to the light direction control element 200 in Embodiment 4, the light direction control element 200 in this embodiment can emit light in three or more angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0260] Example 7

[0261] In Embodiment 4, the first light-transmitting regions 32 of the rectangular parallelepiped are arranged in the X direction, and the first light-absorbing regions 34 are arranged between adjacent first light-transmitting regions 32. However, it is possible for the first light-transmitting regions 32 to have a lattice shape and for the first light-absorbing regions 34 to be disposed in the openings of the lattice. In the light direction control element 200 of this embodiment, the arrangement of the first light-transmitting region 32, the first light-absorbing region 34, the second light-transmitting region 42, and the second light-absorbing region 44 differs from that in other embodiments. Other arrangements of the light direction control element 200 of this embodiment are the same as those of the light direction control element 200 in other embodiments. Next, the arrangement of the first light-transmitting region 32, the first light-absorbing region 34, the second light-transmitting region 42, and the second light-absorbing region 44, as well as the operation of the light direction control element 200, will be described.

[0262] As in other embodiments, the first light-transmitting area 32 in this embodiment is a region that transmits visible light. In this embodiment, the first light-transmitting area 32 is disposed on the first main surface 10a of the first light-transmitting substrate 10. Figure 32 As shown, the first light-transmitting region 32 in this embodiment has a lattice shape. The other configurations of the first light-transmitting region 32 in this embodiment are the same as those in other embodiments.

[0263] In this embodiment, the first light-absorbing region 34 is a region within the lattice opening of the first light-transmitting region 32 and is positioned between the first light-transmitting regions 32. Therefore, the first light-absorbing region 34 in this embodiment has a prism shape and is arranged in a matrix in the X and Y directions. The other configurations of the first light-absorbing region 34 in this embodiment are the same as those in other embodiments.

[0264] In other embodiments, the second light-transmitting area 42 in this embodiment is a region that transmits visible light and is disposed on the first main surface 20a of the second light-transmitting substrate 20. Figure 32 and Figure 33As shown, the second light-transmitting region 42 of this embodiment has the shape of a rectangular parallelepiped extending in the Y direction (a predetermined second direction) and is arranged in the X direction. When viewed from above, the second light-transmitting region 42 of this embodiment is positioned on a lattice extending along the Y direction of the first light-transmitting region 32 and is connected to the first light-transmitting region 32. The width D4 of the second light-transmitting region 42 in the X direction is narrower than the width D3 of the lattice of the first light-transmitting region 32 in the X direction. Therefore, when observing a cross-section on the XZ plane, the shape of the first light-transmitting region 32 is different from the shape of the second light-transmitting region 42. Other configurations of the second light-transmitting region 42 in this embodiment are the same as those in other embodiments.

[0265] As in other embodiments, the second light-absorbing region 44 in this embodiment is the region between adjacent second light-transmitting regions 42. The second light-absorbing region 44 in this embodiment extends in the Y direction. Other configurations of the second light-absorbing region 44 in this embodiment are the same as in other embodiments.

[0266] Next, the operation of the light direction control element 200 in this embodiment will be described.

[0267] Twelfth Vertical Narrow Field Mode

[0268] When the voltage controller 110 executes control to make the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22 equal (V1=V2), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in other embodiments. In the following, this state is referred to as the "twelfth vertical narrow field mode".

[0269] When observing a cross-section on a plane parallel to the XZ plane, including the lattice portion of the first light-transmitting region 32, in the twelfth vertical narrow-field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32, as shown... Figure 34 As shown. In the light transmitted through the first light-transmitting area 32, light except for light near the +Z direction is absorbed by the second light-absorbing area 44, and light near the +Z direction is emitted from the light direction controller 100. When observing a cross-section parallel to the XZ plane including the first light-absorbing area 34, in the twelfth vertical narrow field mode, in the light 510 entering from the surface light source 500, light near the +Z direction is emitted from the light direction controller 100, as in the third vertical narrow field mode of embodiment 4 ( Figure 21 Therefore, in a plane parallel to the XZ plane, the emitted light from the ray direction control element 200 in the twelfth vertical narrow field mode has a narrow angular distribution of approximately 90° (in the +Z direction), as shown below. Figure 35 As shown.

[0270] When observing a cross-section on a plane parallel to the YZ plane, including the lattice portions of the first and second light-transmitting regions 32 and 42, the second light-transmitting region 42, extending along the Y direction, is positioned on the lattice extending along the Y direction of the first light-transmitting region 32. Therefore, in the plane parallel to the YZ plane, including the lattice portions of the first and second light-transmitting regions 32 and 42, the emitted light from the ray direction control element 200 in the twelfth vertical narrow-field mode has a uniform angular distribution, such as... Figure 36 As shown. At the same time, when observing the cross-section on a plane parallel to the YZ plane including the second light-absorbing region 44, the second light-absorbing region 44 extends in the Y direction, and light 510 entering from the surface light source 500 is absorbed by the second light-absorbing region 44.

[0271] As described above, the emitted light from the light direction control element 200 in the twelfth vertical narrow field mode has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane, which includes the lattice portion including the first light-transmitting region 32 and the second light-transmitting region 42. Therefore, in the twelfth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0272] Thirteenth Vertical Narrow Field Mode

[0273] When the voltage controller 110 executes control such that the potential V2 of the second light-transmitting electrode 22 is greater than the potential V1 of the first light-transmitting electrode 12 (V2>V1), only the second light-absorbing region 44 acts as a light-absorbing layer, as in other embodiments. In the following, this state is referred to as the "thirteenth vertical narrow field mode".

[0274] When observing the cross-section on the XZ plane, in the thirteenth vertical narrow-field mode, light 510 entering from the surface light source 500 is transmitted through the first light-transmitting region 32 and the first light-absorbing region 34. Of the light transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, light other than that near the +Z direction is absorbed by the second light-absorbing region 44. Furthermore, of the light transmitted through the first light-transmitting region 32 and the first light-absorbing region 34, light near the +Z direction is emitted from the light direction controller 100. Therefore, in a plane parallel to the XZ plane, the emitted light from the light direction control element 200 in the thirteenth vertical narrow-field mode has a narrow angular distribution of approximately 90° (+Z direction), as shown below. Figure 35 As shown.

[0275] In a plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the thirteenth vertical narrow field mode has a uniform angular distribution, as in the twelfth vertical narrow field mode.

[0276] As described above, the emitted light from the light direction control element 200 in the thirteenth vertical narrow field mode has a narrow angular distribution of approximately 90° (+Z direction) in a plane parallel to the XZ plane, and a uniform angular distribution in a plane parallel to the YZ plane, including the lattice portions of the first and second light-transmitting regions 32. Therefore, in the thirteenth vertical narrow field mode, the light direction control element 200 can limit the viewing angle of the display device 300 in the left-right direction (X direction) to be close to the front surface (+Z direction).

[0277] Fourteenth Vertical Narrow Field Mode

[0278] When the voltage controller 110 executes control such that the potential V1 of the first light-transmitting electrode 12 is greater than the potential V2 of the second light-transmitting electrode 22 (V1>V2), only the first light-absorbing region 34 acts as a light-absorbing layer, as in other embodiments. In the following, this state is referred to as the "fourteenth vertical narrow field mode".

[0279] When observing a cross-section on a plane parallel to the XZ plane excluding the first light-absorbing region 34, in the fourteenth vertical narrow-field mode, light 510 entering from the surface light source 500 exits from the light direction control element 200 without being absorbed by the first light-absorbing region 34 and the second light-absorbing region 44. In the plane parallel to the XZ plane excluding the first light-absorbing region 34, the emitted light from the light direction control element 200 in the fourteenth vertical narrow-field mode has a uniform angular distribution.

[0280] Furthermore, when observing a cross-section on a plane parallel to the XZ plane, including the first light-absorbing region 34, such as Figure 37 As shown, in the light 510 entering from the surface light source 500, light except for light near the +Z direction is absorbed by the second light-absorbing region 44, and light near the +Z direction is emitted from the light direction controller 100. In a plane parallel to the XZ plane including the first light-absorbing region 34, the emitted light of the light direction control element 200 in the fourteenth vertical narrow field mode has a narrow angle distribution of approximately 90° (+Z direction).

[0281] Therefore, based on the entire light direction controller 100, the emitted light of the light direction control element 200 in the fourteenth vertical narrow field mode has the following angular distribution, such as... Figure 35 As shown, in a plane parallel to the XZ plane, the transmittance gradually decreases towards 0° and 180°, with the maximum value at 90°.

[0282] The first light-absorbing region 34 has a prism shape and is arranged in a matrix in the X and Y directions. Thus, in a plane parallel to the YZ plane excluding the first light-absorbing region 34, the emitted light of the light direction control element 200 in the fourteenth vertical narrow-field mode has a uniform angular distribution. Furthermore, in a plane parallel to the YZ plane including the first light-absorbing region 34, the emitted light of the light direction control element 200 in the fourteenth vertical narrow-field mode has a narrow angular distribution of approximately 90° (+Z direction). Therefore, based on the entire light direction controller 100, the emitted light of the light direction control element 200 in the fourteenth vertical narrow-field mode has an angular distribution, such as... Figure 35 As shown, in a plane parallel to the YZ plane, the transmittance gradually decreases towards 0° and 180°, with the maximum value at 90°.

[0283] As described above, the emitted light of the light direction control element 200 in the fourteenth vertical narrow field mode has the following angular distribution, wherein the transmittance gradually decreases towards 0° and 180° in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, with a maximum value at 90°. Therefore, in the fourteenth vertical narrow field mode, the light direction control element 200 can narrow the viewing angle in both the vertical and horizontal directions of the display device 300.

[0284] Thirteenth Wide Field Mode

[0285] When the voltage controller 110 executes control such that the potential V2 of the second transparent electrode 22 is greater than the potential V1 of the first transparent electrode 12, and the difference between potential V2 and potential V1 is greater than the difference between the two in the thirteenth vertical narrow field mode (V2 >> V1), the electrophoretic particles 54 gather on the side of the second transparent electrode 22 of the second light-absorbing region 44, and the first light-absorbing region 34 and the second light-absorbing region 44 can hardly function as a light-absorbing layer. In the following text, this state is referred to as the "thirteenth wide field mode".

[0286] In the thirteenth wide-field mode, the first absorption region 34 and the second absorption region 44 hardly function as light-absorbing layers. Therefore, as Figure 35 and 36 As shown, in both the plane parallel to the XZ plane and the plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the thirteenth wide-field mode has a uniform angular distribution. When viewed from above, the area of ​​the second light-absorbing region 44 where the electrophoretic particles 54 are concentrated is large, and thus, the transmittance decreases in the thirteenth wide-field mode. In the thirteenth wide-field mode, the light direction control element 200 does not limit the viewing angle of the display device 300.

[0287] Fourteenth Wide Field Mode

[0288] When the voltage controller 110 executes control such that the potential V1 of the first transparent electrode 12 is greater than the potential V2 of the second transparent electrode 22, and the difference between potentials V1 and V2 is greater than the difference between the two in the fourteenth vertical narrow field mode (V1>>V2), the electrophoretic particles 54 gather on the side of the first transparent electrode 12 of the first light-absorbing region 34, and the first light-absorbing region 34 and the second light-absorbing region 44 hardly function as light-absorbing layers. In the following text, this state is referred to as the "fourteenth wide field mode".

[0289] In the fourteenth wide-field mode, the first absorption region 34 and the second absorption region 44 hardly function as light-absorbing layers. Therefore, as Figure 35 and 36 As shown, in both the plane parallel to the XZ plane and the plane parallel to the YZ plane, the emitted light from the light direction control element 200 in the fourteenth wide-field mode has a uniform angular distribution. Furthermore, when viewed from above, the area of ​​the first light-absorbing region 34 is smaller than the area of ​​the second light-absorbing region 44, and thus, the transmittance in the fourteenth wide-field mode is higher than that in the thirteenth wide-field mode. In the fourteenth wide-field mode, the light direction control element 200 does not restrict the viewing angle of the display device 300.

[0290] Therefore, the light direction control element 200 of this embodiment can emit light in three or more types of angular distributions by controlling the potential V1 of the first light-transmitting electrode 12 and the potential V2 of the second light-transmitting electrode 22.

[0291] Example 8

[0292] In embodiments 1-7, the first light-transmitting region 32, the first light-absorbing region 34, the second light-transmitting region 42, and the second light-absorbing region 44 are sandwiched between the first light-transmitting substrate 10 including the first light-transmitting electrode 12 and the second light-transmitting substrate 20 including the second light-transmitting electrode 22. However, it is possible for the light direction controller 100 to be configured such that a third light-transmitting substrate 80 is provided between the first light-transmitting region 32 and the first light-absorbing region 34 and the second light-transmitting region 42 and the second light-absorbing region 44. Here, the third light-transmitting substrate 80 includes a third light-transmitting electrode 82 and a fourth light-transmitting electrode 84. Except for including the third light-transmitting substrate 80, the configuration of the light direction control element 200 in this embodiment is the same as that of the light direction control element 200 in embodiment 1.

[0293] The third light-transmitting substrate 80 transmits visible light. In one example, the third light-transmitting substrate 80 is implemented as a light-transmitting film substrate. Figure 38As shown, a third light-transmitting substrate 80 is disposed between the first light-transmitting region 32 and the first light-absorbing region 34, and between the second light-transmitting region 42 and the second light-absorbing region 44. The third light-transmitting substrate 80 includes a third light-transmitting electrode 82 positioned on a first main surface 80a on the side of the first light-transmitting substrate 10. Additionally, the third light-transmitting substrate 80 includes a fourth light-transmitting electrode 84 positioned on a second main surface 80b on the side of the second light-transmitting substrate 20. Therefore, the third light-transmitting electrode 82 and the fourth light-transmitting electrode 84 are arranged between the first light-transmitting region 32 and the first light-absorbing region 34, and between the second light-transmitting region 42 and the second light-absorbing region 44. In one example, the third light-transmitting electrode 82 and the fourth light-transmitting electrode 84 are formed of ITO.

[0294] In this embodiment, the first light-transmitting region 32 and the second light-transmitting region 42, as well as the first light-absorbing region 34 and the second light-absorbing region 44, are connected via the third light-transmitting electrode 82, the third light-transmitting substrate 80, and the fourth light-transmitting electrode 84. The potentials of the third light-transmitting electrode 82 and the fourth light-transmitting electrode 84 are controlled by the voltage controller 110.

[0295] Next, the operation of the light direction control element 200 in this embodiment will be described.

[0296] Light blocking mode

[0297] When the voltage controller 110 executes control to make the potentials V1 of the first light-transmitting electrode 12, V2 of the second light-transmitting electrode 22, V3 of the third light-transmitting electrode 82, and V4 of the fourth light-transmitting electrode 84 equal (V1 = V2 = V3 = V4), the first light-absorbing region 34 and the second light-absorbing region 44 act as light-absorbing layers, as in the light-blocking mode of Embodiment 1. Therefore, when the potentials V1 of the first light-transmitting electrode 12, V2 of the second light-transmitting electrode 22, V3 of the third light-transmitting electrode 82, and V4 of the fourth light-transmitting electrode 84 are equal, the light direction control element 200 blocks the light 510 of the surface light source 500, as in the light-blocking mode of Embodiment 1.

[0298] Fifth diagonal narrow field mode

[0299] When the voltage controller 110 executes control such that the potentials V2 of the second light-transmitting electrode 22, V3 of the third light-transmitting electrode 82, and V4 of the fourth light-transmitting electrode 84 are equal, and the potential V1 of the first light-transmitting electrode 12 is less than V2 to V4 (V2 = V3 = V4 > V1), the electrophoretic particles 54 in the first light-absorbing region 34 aggregate on the side of the third light-transmitting electrode 82, and the electrophoretic particles 54 in the second light-absorbing region 44 are uniformly dispersed, such as... Figure 39 As shown. Therefore, the first light-absorbing region 34 hardly functions as a light-absorbing layer, while the second light-absorbing region 44 functions as a light-absorbing layer. In the following text, this state is referred to as the "fifth diagonal narrow-field mode".

[0300] In the fifth diagonal narrow field mode, the first light absorption region 34 hardly functions as a light absorption layer, and the second light absorption region 44 functions as a light absorption layer. Therefore, in a plane parallel to the XZ plane, the emitted light of the light direction control element 200 in the fifth diagonal narrow field mode has a narrow angular distribution close to 90° - θ, which is the same as that in the first diagonal narrow field mode of Embodiment 1. In addition, in a plane parallel to a plane inclined by an angle of (0° < tilt angle < 2×θ) toward the +X direction with respect to the YZ plane, the emitted light of the light direction control element 200 in the fifth diagonal narrow field mode has a uniform angular distribution.

[0301] Fifteenth vertical narrow field mode

[0302] When the voltage controller 110 performs control such that the potentials V1 of the first light transmissive electrode 12, the potential V3 of the third light transmissive electrode 82, and the potential V4 of the fourth light transmissive electrode 84 are equal and the potential V2 of the second light transmissive electrode 22 is less than the potentials V1, V3, and V4 (V1 = V3 = V4 > V2), the electrophoretic particles 54 in the second light absorption region 44 aggregate on the side of the fourth light transmissive electrode 84, and the electrophoretic particles 54 in the first light absorption region 34 are uniformly dispersed, as Figure 40 shown. Therefore, the second light absorption region 44 hardly functions as a light absorption layer, and the first light absorption region 34 functions as a light absorption layer. Hereinafter, this state is referred to as the "fifteenth vertical narrow field mode".

[0303] In the fifteenth vertical narrow field mode, the second light absorption region 44 hardly serves as a light absorption layer, and the first light absorption region 34 functions as a light absorption layer. Therefore, in a plane parallel to the XZ plane, the emitted light of the light direction control element 200 in the fifteenth vertical narrow field mode has a narrow angular distribution close to 90° (+Z direction), which is the same as that in the first vertical narrow field mode of Embodiment 1. In addition, in a plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the fifteenth vertical narrow field mode has a uniform angular distribution.

[0304] Fifteenth wide field mode

[0305] When the voltage controller 110 performs control such that the potential V1 of the first light transmissive electrode 12 and the potential V2 of the second light transmissive electrode 22 are equal, and the potential V3 of the third light transmissive electrode 82 and the potential V4 of the fourth light transmissive electrode 84 are equal and greater than the potentials V1 and V2 (V1 = V2 < V3 = V4), the electrophoretic particles 54 in the first light absorption region 34 aggregate on the side of the third light transmissive electrode 82, and the electrophoretic particles 54 in the second light absorption region 44 aggregate on the side of the fourth light transmissive electrode 84, as Figure 41 shown. Therefore, the first light absorption region 34 and the second light absorption region 44 hardly function as light absorption layers. Hereinafter, this state is referred to as the "fifteenth wide field mode".

[0306] In the fifteenth wide-field mode, the first light-absorbing region 34 and the second light-absorbing region 44 can hardly function as light-absorbing layers. Therefore, in the plane parallel to the XZ plane and in the plane parallel to the YZ plane, the emitted light of the light direction control element 200 in the fifteenth wide-field mode has a uniform angular distribution, which is the same as in the first wide-field mode and the second wide-field mode of Embodiment 1.

[0307] Therefore, similar to the light direction control element 200 of Embodiment 1, the light direction control element 200 of this embodiment can emit light in three or more types of angular distributions.

[0308] Improved Example

[0309] Embodiments have been described, but various modifications may be made to this disclosure without departing from the spirit and scope thereof.

[0310] For example, it is possible for the first light-transmitting substrate 10 and the second light-transmitting substrate 20 to be formed of light-transmitting resin. It is possible for the third light-transmitting substrate 80 to be configured as a glass substrate. It is possible for the electrophoretic particles 54 to be positively charged.

[0311] Furthermore, it is possible for the first light-transmitting area 32 and the second light-transmitting area 42 to be integrally formed. For example, in Embodiment 1, the first light-transmitting area 32 and the second light-transmitting area 42 can be formed as a light-transmitting layer that is bent in the middle.

[0312] In Embodiment 3, the first light-transmitting region 32 is perpendicular to the first main surface 10a of the first light-transmitting substrate 10. However, it is possible for the first light-transmitting region 32 of Embodiment 3 to be arranged in the opposite direction to the second light-transmitting region 42 with respect to the +Z direction, just like the first light-transmitting region 32 of Embodiment 2.

[0313] In embodiment 8, the third light-transmitting electrode 82 and the fourth light-transmitting electrode 84 are disposed on the third light-transmitting substrate 80, and the third light-transmitting electrode 82 and the fourth light-transmitting electrode 84 are arranged between the first light-transmitting region 32 and the first light-absorbing region 34 and the second light-transmitting region 42 and the second light-absorbing region 44. Figure 42 As shown, it is possible to arrange the fifth light-transmitting electrode 86 between the first light-transmitting region 32 and the first light-absorbing region 34, and between the second light-transmitting region 42 and the second light-absorbing region 44. The fifth light-transmitting electrode 86 is disposed on the first main surface 80a and the second main surface 80b of the third light-transmitting substrate 80 via through holes. In this case, the angular distribution of light transmitted through the light direction controller 100 can be controlled by controlling the potential V1 of the first light-transmitting electrode 12, the potential V2 of the second light-transmitting electrode 22, and the potential V5 of the fifth light-transmitting electrode 86.

[0314] For example, by making the potential V1 of the first light-transmissive electrode 12, the potential V2 of the second light-transmissive electrode 22, and the potential V5 of the fifth light-transmissive electrode 86 equal (V1 = V2 = V5), the light direction control element 200 can block the light 510 from the surface light source 500, as in the light-blocking mode of Example 8. Additionally, by making the potential V1 of the first light-transmissive electrode 12 and the potential V5 of the fifth light-transmissive electrode 86 equal, and making the potential V2 of the second light-transmissive electrode 22 less than the potential V1 and the potential V5 (V1 = V5 > V2), the same angular distribution as in the fifth diagonal narrow field mode of Example 8 can be obtained. Furthermore, by making the potential V2 of the second light-transmissive electrode 22 and the potential V5 of the fifth light-transmissive electrode 86 equal, and making the potential V1 of the first light-transmissive electrode 12 less than the potential V2 and the potential V5 (V1 < V2 = V5), the same angular distribution as in the fifteenth vertical narrow field mode of Example 8 can be obtained. By making the potential V1 of the first light-transmissive electrode 12 and the potential V2 of the second light-transmissive electrode 22 equal, and making the potential V1 and the potential V2 less than the potential V5 of the fifth light-transmissive electrode 86 (V1 = V2 < V5), the angular distribution in the fifteenth wide field mode of Example 8 can be obtained.

[0315] The voltage controller 110 is not limited to a control circuit. The voltage controller 110 can be configured from an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a central processing unit (CPU), and a read only memory (ROM) or the like.

[0316] As Figure 43 shown, it is possible to configure the display device 300 to include the light direction control element 200, the transmissive liquid crystal display panel 215, and the backlight 220. The backlight 220 is arranged on the side opposite to the display surface of the transmissive liquid crystal display panel 215 and supplies light to the transmissive liquid crystal display panel 215. The light direction controller 100 of the light direction control element 200 is arranged between the transmissive liquid crystal display panel 215 and the backlight 220 and controls the angular distribution of the light supplied from the backlight 220 to the transmissive liquid crystal display panel 215

[0317] Some exemplary embodiments have been described for explanatory purposes. Although the previous 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 invention. Thus, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. Therefore, this detailed description should not be understood in a restrictive sense, and the scope of the invention is defined only by the full scope of the included claims and the equivalents authorized by these claims.

Claims

1. A light direction control element, comprising: First light-transmitting substrate; The second light-transmitting substrate faces the first light-transmitting substrate; A first light-transmitting area is disposed on a first main surface of the first light-transmitting substrate and extends from the first light-transmitting substrate toward the second light-transmitting substrate; The second light-transmitting area is disposed on the first main surface of the second light-transmitting substrate facing the first main surface of the first light-transmitting substrate, extends from the second light-transmitting substrate toward the first light-transmitting substrate, and is continuous with the first light-transmitting area; Multiple first light-absorbing regions are positioned within the first light-transmitting regions and extend from the first light-transmitting substrate toward the second light-transmitting substrate; A plurality of second light-absorbing regions are positioned within the second light-transmitting regions, extending from the second light-transmitting substrate toward the first light-transmitting substrate, and are continuous with the first light-absorbing regions; A light-transmitting dispersion medium is enclosed within the first light-absorbing region and the second light-absorbing region; as well as Charged electrophoretic particles are dispersed in the transparent dispersion medium and have a dispersion state that changes according to the applied voltage, wherein When observing cross-sections perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the shapes or tilt angles of the first light-transmitting area and the second light-transmitting area relative to the first main surface of the first light-transmitting substrate are different. When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones are arranged in the same direction, and When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas extend perpendicular to the first main surface of the first light-transmitting substrate, and the plurality of second light-transmitting areas are tilted relative to the direction perpendicular to the first main surface of the first light-transmitting substrate.

2. The light direction control element according to claim 1 further includes: A voltage controller controls the voltage applied to the electrophoretic particles, wherein When the dispersion state of the electrophoretic particles is changed from a dispersion state in which the electrophoretic particles are dispersed in the first light-absorbing region and the second light-absorbing region to a dispersion state formed by a voltage of a first voltage value applied to the electrophoretic particles, wherein the electrophoretic particles are dispersed in one of the first light-absorbing region and the second light-absorbing region and not dispersed in the other of the first light-absorbing region and the second light-absorbing region, the voltage controller applies a second voltage value greater than the first voltage value to the electrophoretic particles to change the dispersion state of the electrophoretic particles via the dispersion state in which the electrophoretic particles are concentrated in one of the first light-absorbing region and the second light-absorbing region.

3. The light direction control element according to claim 1, wherein, When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas have different widths in the direction parallel to the first main surface of the first light-transmitting substrate.

4. The light direction control element according to claim 2, wherein, When viewed from above, the plurality of first light-transmitting areas and the second light-transmitting areas extend in the same direction.

5. The light direction control element according to claim 1, wherein, When viewed from above, the plurality of first light-transmitting areas extend in a predetermined first direction, and the plurality of second light-transmitting areas are arranged on the first light-transmitting areas.

6. The light direction control element according to claim 1, wherein, When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones extend in different directions from each other.

7. The light direction control element according to claim 1, wherein, When viewed from above, the first light-transmitting region has a lattice shape, and a plurality of second light-transmitting regions are arranged in a predetermined second direction.

8. The light direction control element according to claim 1, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and second transparent electrodes.

9. The light direction control element according to claim 1, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a third and a fourth light-transmitting electrode located between the first light-transmitting region and the first light-absorbing region and the second light-transmitting region and the second light-absorbing region. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and third transparent electrodes and the voltage applied by the second and fourth transparent electrodes.

10. The light direction control element according to claim 1, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a fifth light-transmitting electrode between the first light-transmitting area and the first light-absorbing area and the second light-transmitting area and the second light-absorbing area, and The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and fifth transparent electrodes and the voltage applied by the second and fifth transparent electrodes.

11. A light direction control element, comprising: First light-transmitting substrate; The second light-transmitting substrate faces the first light-transmitting substrate; A first light-transmitting area is disposed on a first main surface of the first light-transmitting substrate and extends from the first light-transmitting substrate toward the second light-transmitting substrate; The second light-transmitting area is disposed on the first main surface of the second light-transmitting substrate facing the first main surface of the first light-transmitting substrate, extends from the second light-transmitting substrate toward the first light-transmitting substrate, and is continuous with the first light-transmitting area; Multiple first light-absorbing regions are positioned within the first light-transmitting regions and extend from the first light-transmitting substrate toward the second light-transmitting substrate; A plurality of second light-absorbing regions are positioned within the second light-transmitting regions, extending from the second light-transmitting substrate toward the first light-transmitting substrate, and are continuous with the first light-absorbing regions; A light-transmitting dispersion medium is enclosed within the first light-absorbing region and the second light-absorbing region; as well as Charged electrophoretic particles are dispersed in the transparent dispersion medium and have a dispersion state that changes according to the applied voltage, wherein When observing cross-sections perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the shapes or tilt angles of the first light-transmitting area and the second light-transmitting area relative to the first main surface of the first light-transmitting substrate are different. When viewed from above, multiple first light-transmitting areas and multiple second light-transmitting areas are arranged in the same direction, and When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas are tilted in opposite directions relative to the direction perpendicular to the first main surface of the first light-transmitting substrate.

12. The light direction control element according to claim 11, further comprising: A voltage controller controls the voltage applied to the electrophoretic particles, wherein When the dispersion state of the electrophoretic particles is changed from a dispersion state in which the electrophoretic particles are dispersed in the first light-absorbing region and the second light-absorbing region to a dispersion state formed by a voltage of a first voltage value applied to the electrophoretic particles, wherein the electrophoretic particles are dispersed in one of the first light-absorbing region and the second light-absorbing region and not dispersed in the other of the first light-absorbing region and the second light-absorbing region, the voltage controller applies a second voltage value greater than the first voltage value to the electrophoretic particles to change the dispersion state of the electrophoretic particles via the dispersion state in which the electrophoretic particles are concentrated in one of the first light-absorbing region and the second light-absorbing region.

13. The light direction control element according to claim 11, wherein, When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas have different widths in the direction parallel to the first main surface of the first light-transmitting substrate.

14. The light direction control element according to claim 12, wherein, When viewed from above, the plurality of first light-transmitting areas and the second light-transmitting areas extend in the same direction.

15. The light direction control element according to claim 11, wherein, When viewed from above, the plurality of first light-transmitting areas extend in a predetermined first direction, and the plurality of second light-transmitting areas are arranged on the first light-transmitting areas.

16. The light direction control element according to claim 11, wherein, When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones extend in different directions from each other.

17. The light direction control element according to claim 11, wherein, When viewed from above, the first light-transmitting region has a lattice shape, and a plurality of second light-transmitting regions are arranged in a predetermined second direction.

18. The light direction control element according to claim 11, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and second transparent electrodes.

19. The light direction control element according to claim 11, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a third and a fourth light-transmitting electrode located between the first light-transmitting region and the first light-absorbing region and the second light-transmitting region and the second light-absorbing region. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and third transparent electrodes and the voltage applied by the second and fourth transparent electrodes.

20. The light direction control element according to claim 11, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a fifth light-transmitting electrode between the first light-transmitting area and the first light-absorbing area and the second light-transmitting area and the second light-absorbing area, and The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and fifth transparent electrodes and the voltage applied by the second and fifth transparent electrodes.

21. A light direction control element, comprising: First light-transmitting substrate; The second light-transmitting substrate faces the first light-transmitting substrate; A first light-transmitting area is disposed on a first main surface of the first light-transmitting substrate and extends from the first light-transmitting substrate toward the second light-transmitting substrate; The second light-transmitting area is disposed on the first main surface of the second light-transmitting substrate facing the first main surface of the first light-transmitting substrate, extends from the second light-transmitting substrate toward the first light-transmitting substrate, and is continuous with the first light-transmitting area; Multiple first light-absorbing regions are positioned within the first light-transmitting regions and extend from the first light-transmitting substrate toward the second light-transmitting substrate; A plurality of second light-absorbing regions are positioned within the second light-transmitting regions, extending from the second light-transmitting substrate toward the first light-transmitting substrate, and are continuous with the first light-absorbing regions; A light-transmitting dispersion medium is enclosed within the first light-absorbing region and the second light-absorbing region; as well as Charged electrophoretic particles are dispersed in the transparent dispersion medium and have a dispersion state that changes according to the applied voltage, wherein When observing cross-sections perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the shapes or tilt angles of the first light-transmitting area and the second light-transmitting area relative to the first main surface of the first light-transmitting substrate are different. When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones are arranged in a matrix, and When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas extend perpendicular to the first main surface of the first light-transmitting substrate, and the plurality of second light-transmitting areas are tilted relative to the direction perpendicular to the first main surface of the first light-transmitting substrate.

22. The light direction control element according to claim 21, further comprising: A voltage controller controls the voltage applied to the electrophoretic particles, wherein When the dispersion state of the electrophoretic particles is changed from a dispersion state in which the electrophoretic particles are dispersed in the first light-absorbing region and the second light-absorbing region to a dispersion state formed by a voltage of a first voltage value applied to the electrophoretic particles, wherein the electrophoretic particles are dispersed in one of the first light-absorbing region and the second light-absorbing region and not dispersed in the other of the first light-absorbing region and the second light-absorbing region, the voltage controller applies a second voltage value greater than the first voltage value to the electrophoretic particles to change the dispersion state of the electrophoretic particles via the dispersion state in which the electrophoretic particles are concentrated in one of the first light-absorbing region and the second light-absorbing region.

23. The light direction control element according to claim 21, wherein, When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas have different widths in the direction parallel to the first main surface of the first light-transmitting substrate.

24. The light direction control element according to claim 22, wherein, When viewed from above, the plurality of first light-transmitting areas and the second light-transmitting areas extend in the same direction.

25. The light direction control element according to claim 21, wherein, When viewed from above, the plurality of first light-transmitting areas extend in a predetermined first direction, and the plurality of second light-transmitting areas are arranged on the first light-transmitting areas.

26. The light direction control element according to claim 21, wherein, When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones extend in different directions from each other.

27. The light direction control element according to claim 21, wherein, When viewed from above, the first light-transmitting region has a lattice shape, and a plurality of second light-transmitting regions are arranged in a predetermined second direction.

28. The light direction control element according to claim 21, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and second transparent electrodes.

29. The light direction control element according to claim 21, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a third and a fourth light-transmitting electrode located between the first light-transmitting region and the first light-absorbing region and the second light-transmitting region and the second light-absorbing region. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and third transparent electrodes and the voltage applied by the second and fourth transparent electrodes.

30. The light direction control element according to claim 21, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a fifth light-transmitting electrode between the first light-transmitting area and the first light-absorbing area and the second light-transmitting area and the second light-absorbing area, and The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and fifth transparent electrodes and the voltage applied by the second and fifth transparent electrodes.

31. A light direction control element, comprising: First light-transmitting substrate; The second light-transmitting substrate faces the first light-transmitting substrate; A first light-transmitting area is disposed on a first main surface of the first light-transmitting substrate and extends from the first light-transmitting substrate toward the second light-transmitting substrate; The second light-transmitting area is disposed on the first main surface of the second light-transmitting substrate facing the first main surface of the first light-transmitting substrate, extends from the second light-transmitting substrate toward the first light-transmitting substrate, and is continuous with the first light-transmitting area; Multiple first light-absorbing regions are positioned within the first light-transmitting regions and extend from the first light-transmitting substrate toward the second light-transmitting substrate; A plurality of second light-absorbing regions are positioned within the second light-transmitting regions, extending from the second light-transmitting substrate toward the first light-transmitting substrate, and are continuous with the first light-absorbing regions; A light-transmitting dispersion medium is enclosed within the first light-absorbing region and the second light-absorbing region; as well as Charged electrophoretic particles are dispersed in the transparent dispersion medium and have a dispersion state that changes according to the applied voltage, wherein When observing cross-sections perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the shapes or tilt angles of the first light-transmitting area and the second light-transmitting area relative to the first main surface of the first light-transmitting substrate are different. When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones are arranged in a matrix, and When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas are tilted in opposite directions relative to the direction perpendicular to the first main surface of the first light-transmitting substrate.

32. The light direction control element according to claim 31, further comprising: A voltage controller controls the voltage applied to the electrophoretic particles, wherein When the dispersion state of the electrophoretic particles is changed from a dispersion state in which the electrophoretic particles are dispersed in the first light-absorbing region and the second light-absorbing region to a dispersion state formed by a voltage of a first voltage value applied to the electrophoretic particles, wherein the electrophoretic particles are dispersed in one of the first light-absorbing region and the second light-absorbing region and not dispersed in the other of the first light-absorbing region and the second light-absorbing region, the voltage controller applies a second voltage value greater than the first voltage value to the electrophoretic particles to change the dispersion state of the electrophoretic particles via the dispersion state in which the electrophoretic particles are concentrated in one of the first light-absorbing region and the second light-absorbing region.

33. The light direction control element according to claim 31, wherein, When observing the cross-section perpendicular to the first main surface of the first light-transmitting substrate and the first main surface of the second light-transmitting substrate, the plurality of first light-transmitting areas and the plurality of second light-transmitting areas have different widths in the direction parallel to the first main surface of the first light-transmitting substrate.

34. The light direction control element according to claim 32, wherein, When viewed from above, the plurality of first light-transmitting areas and the second light-transmitting areas extend in the same direction.

35. The light direction control element according to claim 31, wherein, When viewed from above, the plurality of first light-transmitting areas extend in a predetermined first direction, and the plurality of second light-transmitting areas are arranged on the first light-transmitting areas.

36. The light direction control element according to claim 31, wherein, When viewed from above, multiple first light-transmitting zones and multiple second light-transmitting zones extend in different directions from each other.

37. The light direction control element according to claim 31, wherein, When viewed from above, the first light-transmitting region has a lattice shape, and a plurality of second light-transmitting regions are arranged in a predetermined second direction.

38. The light direction control element according to claim 31, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and second transparent electrodes.

39. The light direction control element according to claim 31, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a third and a fourth light-transmitting electrode located between the first light-transmitting region and the first light-absorbing region and the second light-transmitting region and the second light-absorbing region. The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and third transparent electrodes and the voltage applied by the second and fourth transparent electrodes.

40. The light direction control element according to claim 31, wherein... A first light-transmitting electrode is disposed on a first main surface of the first light-transmitting substrate, and a second light-transmitting electrode is disposed on a first main surface of the second light-transmitting substrate. The light direction control element further includes a fifth light-transmitting electrode between the first light-transmitting area and the first light-absorbing area and the second light-transmitting area and the second light-absorbing area, and The dispersion state of the electrophoretic particles changes according to the voltage applied by the first and fifth transparent electrodes and the voltage applied by the second and fifth transparent electrodes.

41. A display device, comprising: The light direction control element according to any one of claims 1 to 40; as well as Display panel, in which The light direction control element is arranged on the display surface of the display panel.

42. A display device, comprising: The light direction control element according to any one of claims 1 to 40; Transmissive liquid crystal display panel; as well as A backlight, which is arranged on the side of the transmissive liquid crystal display panel opposite to the display surface, supplies light to the transmissive liquid crystal display panel, wherein... The light direction control element is arranged between the transmissive liquid crystal display panel and the backlight.

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