JP7219591B2 - light beam direction control element - Google Patents

Description

The present disclosure relates to light beam steering elements.

2. Description of the Related Art In recent years, viewing angle control devices have been used in smartphones, ATMs, aircraft entertainment displays, etc., in order to make it difficult for people other than the user to see the display content. In such a viewing angle control device, a light shielding pattern for controlling the viewing angle is formed, and a light shielding material (for example, electrophoretic particles or black ink) or the like is injected into the light shielding pattern (Patent Document 1). reference).

U.S. Pat. No. 7,751,667 WO2015/122083

In the manufacture of viewing angle control devices, it is desired to speed up the injection of the light shielding material. An object of the present disclosure is to provide a beam direction control element capable of injecting a light shielding material at high speed.

In order to solve the above problems, one aspect of the present disclosure employs the following configuration. The light direction control element includes a first transparent substrate, a second transparent substrate arranged to face the first transparent substrate, and a plurality of light beam direction control elements arranged between the first transparent substrate and the second transparent substrate. a light-shielding element, a plurality of light-transmitting regions disposed between the first transparent substrate and the second transparent substrate and having sidewalls surrounded by any one of the plurality of light-shielding elements; the first transparent substrate and the a resin layer disposed between the second transparent substrate and surrounding the outer periphery of the light-transmitting region pattern composed of the plurality of light-transmitting regions and having a sealed first opening; and the first opening of the resin layer. and a first buffer region in which a light shielding element is implanted and which is sandwiched between the light transmitting region pattern.

According to the present disclosure, it is possible to provide a beam direction control element capable of injecting a light shielding material at high speed.

2 is a cross-sectional view showing an example of a light beam direction control element in a narrow-field mode (narrow-field state) in Example 1. FIG. 4 is a cross-sectional view showing an example of a light beam direction control element in a wide-field mode (wide-field state) in Example 1. FIG. 4 is a plan view showing an example of a light beam direction control element in Example 1. FIG. 4 is a plan view showing an example of a light beam direction control element in Example 1. FIG. 4 is a plan view showing an example of a light beam direction control element in Example 1. FIG. 4 is a plan view showing an example of a light beam direction control element in Example 1. FIG. 2 is a plan view showing an example of a light-direction control element before an electrophoresis element is injected in Embodiment 1. FIG. FIG. 10 is a plan view showing an example of a light direction control element before an electrophoresis element is injected in Example 2; FIG. 10 is a plan view showing an example of a light direction control element before an electrophoresis element is injected in Example 3; FIG. 10 is an explanatory view showing an example of a process (transparent conductive film forming process) of a method for manufacturing a light direction control element in Example 3; FIG. 10 is an explanatory view showing an example of a process (transparent conductive film forming process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (photosensitive resin lamination process) of a method for manufacturing a light beam direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of the steps (exposure light irradiation step and position control step) of the method for manufacturing the light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (dam forming process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (transparent substrate installation process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (resin layer forming process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (electrophoresis element filling process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is a plan view showing an example of a light direction control element before an electrophoresis element is injected in Example 4; FIG. 11 is a plan view showing an example of a light-direction control element before an electrophoresis element is injected in Example 5; FIG. 11 is a plan view showing an example of a light-direction control element before an electrophoresis element is injected in Example 6; FIG. 11 is a plan view showing an example of a light-direction control element before an electrophoresis element is injected in Embodiment 7; FIG. 11 is an explanatory diagram showing an example of a process (resin layer forming process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (transparent substrate installation process) of a method for manufacturing a light direction control element in Example 3; FIG. 11 is an explanatory diagram showing an example of a process (electrophoresis element filling process) of a method for manufacturing a light direction control element in Example 3; FIG. 21 is a cross-sectional view showing an example of a light beam direction control element in a narrow-field mode (narrow-field state) in Example 8;

Embodiments will be described below with reference to the accompanying drawings. It should be noted that the present embodiment is merely an example for realizing the present disclosure and does not limit the technical scope of the present disclosure. The same reference numerals are given to the common components in each figure. Also, the shapes depicted in the drawings do not necessarily match the actual dimensions and proportions.

FIG. 1 is a cross-sectional view showing an example of a light beam direction control element in a narrow-field mode (narrow-field state). FIG. 2 is a cross-sectional view showing an example of a beam direction control element in a wide-field mode (wide-field state).

The light direction control element 11 includes a first transparent substrate 21 , a transparent conductive film 31 , a light transmission region 40 , an electrophoretic element 60 , a second transparent substrate 22 and a transparent conductive film 32 . The transparent conductive film 31 is formed on the surface (main surface) 21 a of the first transparent substrate 21 . The transparent conductive film 32 is formed on the surface (main surface) 22 a of the second transparent substrate 22 . The first transparent substrate 21 and the second transparent substrate 22 are arranged such that the main surface 31a of the transparent conductive film 31 and the main surface 32a of the transparent conductive film 32 face each other.

In the present disclosure, the direction perpendicular to the principal planes of the display panel 5 and the beam direction control element 11 is called the Z-axis direction, and the two directions perpendicular to the principal planes are called the X-axis direction and the Y-axis direction, respectively. The Z-axis direction is the lamination direction of the transparent substrate and the transparent conductive film.

The electrophoresis element 60 is arranged so as to be sandwiched between the principal surface 31 a of the transparent conductive film 31 and the principal surface 32 a of the transparent conductive film 32 . The electrophoretic element 60 includes electrophoretic particles 61 (colored) and a dispersion medium 62 . 1 and 2, the entire upper surface 60a of the electrophoretic element 60 is in contact with the transparent conductive film 32, and the entire lower surface 60b of the electrophoretic element 60 is in contact with the transparent conductive film 31. FIG.

On the main surface 31a of the transparent conductive film 31, the light transmission regions 40 and the electrophoretic elements 60 are alternately arranged (without overlapping each other). Similarly, on the main surface 32a of the transparent conductive film 32, the light transmission regions 40 and the electrophoretic elements 60 are alternately arranged (without overlapping each other).

Note that cross-sections of the light transmission region 40 and the dispersion medium 62 are shown without hatching for easy viewing. The light transmission region 40 is arranged in the gap between the transparent conductive films 31 and 32 .

The narrow-field mode shown in FIG. 1 is realized by dispersing the electrophoretic particles 61 in the electrophoretic element 60 arranged between the light transmission regions 40 in the dispersion medium 62 . As a result, the spread of light transmitted from bottom to top in the drawing is restricted by the electrophoretic element 60 between the first transparent substrate 21 and the second transparent substrate 22 . As a result, when compared before and after transmission, the viewing angle becomes narrower, resulting in a narrow viewing mode.

On the other hand, the wide-field mode shown in FIG. 2 is realized by concentrating the electrophoretic particles 61 near the transparent conductive film 31 . For example, the electrophoretic particles 61 are gathered in the vicinity of the transparent conductive film 31 by setting the relative potential of the transparent conductive film 31 with respect to the transparent conductive film 32 to a polarity opposite to the surface charge of the electrophoretic particles 61 . As a result, the spread of light transmitted from bottom to top in the drawing is hardly restricted by the electrophoretic particles 61 between the first transparent substrate 21 and the second transparent substrate 22 . As a result, there is almost no difference in viewing angle when compared before and after transmission, and the wide viewing mode is established.

That is, when the surface charge of the electrophoretic particles 61 is negative (-), the transparent conductive film 31 is used as the positive electrode. When the surface charge of the electrophoretic particles 61 is positive (+), the transparent conductive film 31 is used as the negative electrode.

Hereinafter, the configuration contents in the case where the surface charges of the electrophoretic particles 61 are negative (-) will be described. Even when the surface charge of the electrophoretic particles 61 is positive (+), it can be handled similarly by reversing the polarity of the transparent conductive film.

The transparent conductive film 31 is arranged so as to cover the main surface 21a of the first transparent substrate 21 . Similarly, the transparent conductive film 32 is arranged so as to cover the main surface 22a of the second transparent substrate 22 . However, openings may be provided in portions of the transparent conductive films 31 and 32 that are not in contact with the electrophoretic element 60 . That is, in this case, the light transmission region 40 is arranged in the opening. Further, the main surface 21a of the first transparent substrate 21 and the light transmission region 40 are in contact with each other at the opening of the transparent conductive film 31, and the main surface 22a of the second transparent substrate 22 and the light transmission region 40 are in contact with each other at the opening of the transparent conductive film 32. 40 touches.

Next, the configuration of the beam direction control element 11 will be described in more detail with reference to FIG. The first transparent substrate 21 is made of, for example, a glass substrate, PET (Poly Ethylene Terephthalate), PC (Poly Carbonate), PEN (Poly Ethylene Naphthalate), or COT (Cyclo Olefin Polymer). The same applies to the second transparent substrate 22 as well.

The film thickness of the transparent conductive film 31 is suitably within the range of 10 [nm] to 1000 [nm], and is 50 [nm] in this embodiment. As a constituent material of the transparent conductive film 31, ITO (Indium Tin Oxide), ZnO, IGZO (Indium Gallium Zinc Oxide), conductive nanowires, or the like can be employed, and ITO is used in this embodiment. The same applies to the transparent conductive film 32 as well.

The height of the light transmission region 40 is preferably in the range of 3 [μm] to 300 [μm], and is 60 [μm] in this embodiment. The width of the light transmission region 40 (light transmission pattern width) is preferably in the range of 1 [μm] to 150 [μm], and is 20 [μm] in this embodiment. Furthermore, the width between the light transmission regions 40 is preferably in the range of 0.25 [μm] to 40 [μm], and is 5 [μm] in this embodiment.

The electrophoretic elements 60, which are a mixture of the electrophoretic particles 61 and the dispersion medium 62, are arranged between the light transmitting regions 40, as described above.

Next, four examples shown in FIGS. 3 to 6 will be described as layout examples of the light transmission regions 40 and the electrophoretic elements 60. FIG. 3 to 6 are examples of plan views of the beam direction control element 11. FIG. 3 to 6, illustration of the transparent conductive film 32 and the second transparent substrate 22 is omitted. 3 to 6, a resin layer, which will be described later, is also omitted.

An example (first example) of the structure of the first square pattern in FIG. 3 has a planar shape in which square light-transmitting regions 40 are arranged in a lattice. Also, the electrophoretic elements 60 (the transparent conductive films 31 and 32) fill the gaps between the plurality of light transmitting regions 40. FIG. In the first example, the light beam direction control element 11 is formed so that the light transmission pattern width 41a corresponding to the width of each light transmission region 40 is equal to the light transmission pattern width 42a, and the width of the electrophoretic element 60 (light The light shielding pattern width 41b and the light shielding pattern width 42b corresponding to the width between the transmissive regions 40 are also formed to be equal.

An example (second example) of the structure of the second square pattern in FIG. 4 has a planar shape in which square light transmission regions 40 are arranged in a staggered manner. Also, the electrophoretic elements 60 (the transparent conductive films 31 and 32) fill the gaps between the plurality of light transmitting regions 40. FIG. The light beam direction control element 11 is formed such that the light transmission pattern width 41a corresponding to the width of each light transmission region 40 and the light transmission pattern width 42a are equal to each other, and the width of the electrophoresis element 60 (the mutual width of the light transmission regions 40) is equal. The light shielding pattern width 41b and the light shielding pattern width 42b corresponding to the width between the light shielding patterns are also formed to be equal.

The example (third example) of the structure of the rectangular pattern in FIG. 5 has a planar shape in which rectangular light-transmitting regions 40 are arranged in a staggered manner. Also, the electrophoretic elements 60 (the transparent conductive films 31 and 32) fill the gaps between the plurality of light transmitting regions 40. FIG. In the third example, the beam direction control element 11 is formed such that the light transmission pattern width 42a is longer than the light transmission pattern width 41a. On the other hand, the light shielding pattern width 41b and the light shielding pattern width 42b are formed to have the same length.

In the example (fourth example) of the stripe pattern structure shown in FIG. 6, the plane shape of the light transmission region 40 and the electrophoresis element 60 (the transparent conductive films 31 and 32) forms a stripe shape. In the fourth example, the light direction control element 11 is arranged such that the light transmission pattern width 41a of each light transmission region 40 and the light shielding pattern width 41b of the electrophoresis element 60 are alternately continuous. In the case of the stripe pattern, the plurality of transparent conductive films 31 and 32 are electrically connected outside (not shown) and driven.

In any of the first to fourth examples, in order to realize a high transmittance of the light beam direction control element 11, when the light blocking pattern width 41b is set to 1, the ratio of the light transmitting pattern width 41a to the light transmitting pattern width 41a is It should be three times or more (preferably four times or more) (light shielding pattern width 41b/light transmission pattern width 41a≧1/3 (preferably 1/4)). Similarly, when the light-shielding pattern width 42b is 1, the ratio of the light-transmitting pattern width 42a needs to be 3 times or more (preferably 4 times or more) (that is, light-shielding pattern width 42b/light-transmitting pattern width 42a > 1/3 (preferably 1/4).

Although the details will be described later, in the manufacturing process of the light direction control element 11, first, the light transmission region 40 is formed on the first transparent substrate 21 on which the transparent conductive film 31 is laminated. A second transparent substrate 22 having a transparent conductive film 32 is placed on the surface of the light transmission region 40 . Then, a resin layer having an injection hole is formed so as to cover the outer periphery of the pattern composed of the light transmission regions 40 . Finally, the electrophoresis element 60 is injected from the injection hole of the resin layer by, for example, vacuum injection or injection using capillary action under atmospheric pressure. The injection hole is then sealed.

Here, in FIGS. 3 to 6, it is assumed that the electrophoretic element 60 is injected only through the opening 63 while the electrophoretic element 60 has not yet been injected. The arrows in the beam steering element 11 in FIGS. 3-6 indicate the injection flow of the electrophoretic element 60 in this assumption.

In the example of FIG. 6, the injection itself of the electrophoresis element 60 in the Y-axis direction is impossible. In the examples of FIGS. 3 to 5, since the ratio of the width of the light-transmitting pattern to the width of the light-shielding pattern is three times or more, the injection speed of the electrophoretic element 60 in the X-axis direction reduces the electricity flow in the Y-axis direction. The injection speed of the migration element 60 is slow.

A configuration for performing high-speed injection of the electrophoretic element 60 will be described below with reference to FIG. FIG. 7 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In FIG. 7, illustration of the transparent conductive film 32 and the second transparent substrate 22 is omitted. Also, in FIG. 7, the pattern of the light transmission region 40 is the above-described first square pattern (first example), but other patterns (for example, the above-described second, third, or fourth example). may be Also, in FIG. 7, arrows indicate the flow of the electrophoresis element 60 when the electrophoresis element 60 is injected through an injection hole, which will be described later. In FIG. 7, the vertical direction is the X-axis direction, and the horizontal direction is the Y-axis direction. The same applies to other plan views showing an example of the light direction control element 11 before the electrophoresis element 60 is injected, which will be described later.

Hereinafter, a region in which the electrophoretic element 60 is injected into the gap between the light-transmitting regions 40 in the pattern of the light-transmitting regions 40 will also be referred to as an electrophoretic element injection region.

In the example of FIG. 7 , the light direction control element 11 includes a resin layer 80 surrounding the outer periphery of the first square pattern of light transmission areas 40 . The resin layer 80 has an injection hole 81 for injecting the electrophoresis element 60 . The width of the injection hole 81 is, for example, about 1 to 10 [mm], preferably 5 [mm] or less. Epoxy resin, for example, can be used as a constituent material of the resin layer 80 . A buffer region 90 that is a gap is provided between the surface of the resin layer 80 on which the injection hole 81 is provided and the first square pattern of the light transmission region 40 . The width of the buffer region 90 in the X-axis direction is desirably about 10 to 1000 times the light transmission pattern width 41a, for example, about 1 to 10 [mm].

When the electrophoresis element 60 is injected from the injection hole 81 , the electrophoresis element 60 spreads in the buffer region 90 in the Y-axis direction. After that, the electrophoresis element 60 spreads in the X-axis direction of the electrophoresis element injection region from the portion of the electrophoresis element injection region in contact with the buffer region 90 . Since the buffer region 90 has a sufficiently large width compared to the width of the light-shielding pattern, the speed at which the electrophoretic element 60 spreads in the Y-axis direction in the buffer region 90 is the same as the speed at which the electrophoretic element 60 spreads in the Y-axis direction in the electrophoretic element injection region. Sufficiently higher than the spreading speed in the direction.

Therefore, compared to the case where the buffer region 90 does not exist (that is, the surface of the resin layer 80 having the injection hole 81 is in contact with the first square pattern), the electrophoresis element 60 is injected into the entire electrophoresis element injection area. Increases injection speed.

In the example of FIG. 7, the buffer region 90 is in contact with the entire surface of the resin layer 80 having the injection hole 81, but only a portion of the surface (however, the buffer region 90 is in contact with the injection hole 81). ). In this case, the width of the buffer region 90 in the Y-axis direction is preferably ten times or more the width of the light-shielding pattern. In addition, in the example of FIG. 7 , the injection hole 81 is provided substantially at the center in the Y-axis direction, but may be provided at another position as long as it is in contact with the buffer region 90 .

After the electrophoresis element injection region and the buffer region 90 are filled with the electrophoresis element 60, the injection hole 81 is sealed with the same material as the resin layer 80, for example. If the number and width of the injection holes 81 are increased, the injection speed of the electrophoresis element 60 is increased. is preferably 5 [mm] or less as described above.

In this embodiment, the light beam direction control element 11 capable of switching between the narrow-field mode and the wide-field mode has been described, but the light-direction control element 11 may be capable of realizing only the narrow-field mode. . In this case, for example, instead of the electrophoretic element 60, black ink or the like is injected into the light direction control element 11 as a light shielding material. Also, the light direction control element 11 may not have the transparent conductive film 31 and the transparent conductive film 32 .

Differences from the first embodiment will be described. FIG. 8 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the resin layer 80 has an exhaust hole 82 on the surface opposite to the surface having the injection hole 81 . A buffer region 91, which is a gap, is further provided between the surface of the resin layer 80 on which the exhaust holes 82 are provided and the first square pattern of the light transmission region 40. As shown in FIG. The width of the buffer area 91 in the X-axis direction is, for example, about 1 to 10 mm, like the buffer area 90 .

As a result, even if air remains in the electrophoresis element injection area when the electrophoresis element 60 is injected, the air is exhausted from the exhaust hole 82 via the buffer area 91 . Therefore, in this embodiment, the electrophoretic elements 60 can be evenly injected into the entire electrophoretic element injection region. The electrophoresis element 60 spreads over the entire buffer area 91 after spreading over the entire electrophoresis element injection region.

In the example of FIG. 8, the exhaust hole 82 is provided on the surface of the resin layer 80 facing the surface having the injection hole 81, but it is provided on a surface other than the surface having the injection hole 81. good too. In this case, a buffer region 91 is provided between the other surface and the first square pattern of light transmission regions 40 . Also, although the exhaust hole 82 is provided substantially in the center in the Y-axis direction, it may be provided at another position as long as it is in contact with the buffer area 91 .

Differences from the second embodiment will be described. FIG. 9 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the beam direction control element 11 has a dam 85 between the surface of the resin layer 80 having no injection holes 81 and exhaust holes 82 and the first square pattern of the light transmission regions 40 . The width of the dam 85 is equal to or greater than the light transmission pattern width 41a, preferably five times or more.

A constituent material of the dam 85 is, for example, a photosensitive resin or the like. The constituent material of the dam 85 may be the same as the constituent material of the light transmission region 40 . The resin of the resin layer 80 is dammed up by the dam 85, so that the resin can be prevented from entering the electrophoretic element injection region, and further narrowing of the frame becomes possible.

10A to 10G illustrating each step of the manufacturing method of the light beam direction control element 11 according to the present embodiment. First, as shown in FIG. 10A, the transparent conductive film 31 is formed on the surface (principal surface) of the first transparent substrate 21 (transparent conductive film forming step). Next, as shown in FIG. 10B, a transparent photosensitive resin layer 41 is laminated as a negative photoresist film on the main surface side of the first transparent substrate 21 on which the transparent conductive film 31 is formed (photosensitive resin layer 41). resin lamination process). In addition, the transparent photosensitive resin layer 41 is a member that becomes the light transmission region 40 through a transmission region forming process described later.

Next, as shown in FIG. 10C, the transparent photosensitive resin layer 41 is exposed by irradiating the transparent photosensitive resin layer 41 with exposure light 75 through a photomask 70 having a mask pattern 71 (exposure light irradiation step). ). In this exposure light irradiation step, alignment marks (not shown) formed on the first transparent substrate 21 and the photomask 70 are aligned so that the position of the mask pattern 71 corresponds to the region into which the electrophoretic element 60 is injected. ) to control the positions of the photomask 70 and the first transparent substrate 21 (position control step).

Then, the exposed transparent photosensitive resin layer 41 is developed to form a plurality of light transmission regions 40 separated from each other as shown in FIG. 10D (transmission region forming step).

Subsequently, as shown in FIG. 10E, a dam 85 is formed on the first transparent substrate 21 and outside the light transmitting region 40 (dam forming step). If the material of the dam 85 is the same as that of the light transmission region 40, the light transmission region 40 and the dam 85 may be formed at the same time by the position control step and the transmission region forming step.

Subsequently, as shown in FIG. 10F, the second transparent substrate 22 having the transparent conductive film 32 is installed on the surface of the light transmission region 40 (transparent substrate installation step).

Subsequently, as shown in FIG. 10G, after securing a buffer region (buffer region 90 and buffer region 91 in this embodiment), a resin layer 80 is formed along the outer periphery of the dam 85 (resin layer formation). process). At this time, in this embodiment, the resin layer 80 is not formed in the portions corresponding to the injection hole 81 and the exhaust hole 82 .

Then, as shown in FIG. 10H, the gap formed by the transparent conductive film 31, the light transmission region 40, and the transparent conductive film 32 is filled with the electrophoretic element 60 (electrophoretic element filling step).

In the above description based on FIGS. 10A to 10G, the method in which the transparent substrate installation step is followed by the migration element filling step is shown. The directional control element 11 can be manufactured.

10A to 10E, the electrophoresis element filling step of filling the electrophoresis element 60 between the light transmission regions 40 is executed prior to the transparent substrate installation step, and then, A transparent substrate installation process may be performed to install the second transparent substrate 22 having the transparent conductive film 32 on the surfaces of the light transmission region 40 and the electrophoresis element 60 .

In addition, although the method of forming the resin layer 80 following the placement of the second transparent substrate 22 has been shown, the light direction control element 11 can be similarly manufactured by reversing the order of these two steps. be able to.

10A to 10E, a resin layer forming step for forming a resin layer 80 on the outside of the dam 85 is performed prior to the transparent substrate installing step, as shown in FIG. 15A. After that, as shown in FIG. 15B, a transparent substrate installation step is performed to install the second transparent substrate 22 having the transparent conductive film 32 on the surfaces of the light transmission region 40, the dam 85, and the resin layer 80. FIG. After that, as shown in FIG. 15C, an electrophoresis element filling step of filling the electrophoresis element 60 into the gap formed by the transparent conductive film 31, the light transmission region 40, and the transparent conductive film 32 may be performed.

Here, the exposure light 75 used for the exposure is parallel light with respect to the stacking direction (the direction in which the transparent photosensitive resin layer 41 and the like are stacked). A UV light source is used as a light source for the exposure light 75 , and UV light with a wavelength of 365 [nm], for example, is used as the exposure light 75 in the exposure light irradiation step in this embodiment.

The exposure amount for this irradiation is preferably in the range of 100 [mJ/cm ² ] to 1000 [mJ/cm ² ], and in this embodiment, the exposure amount of the exposure light 75 is 200 [mJ/cm ² ]. be.

As a method for forming the transparent photosensitive resin layer 41 in the exposure light irradiation step, for example, any film forming method such as a slit die coater, wire coater, applicator, dry film transfer, spray coating, or screen printing may be used. can be done. By such a film forming method, in this embodiment, the thickness of the transparent photosensitive resin layer 41, which is appropriately within the range of 30 [μm] to 300 [μm], was formed to be 60 [μm].

As the transparent photosensitive resin used for the transparent photosensitive resin layer 41, for example, a chemically amplified photoresist (trade name “SU-8”) manufactured by Kayaku Microchem can be used. The features of this transparent photosensitive resin are as follows.

The first feature is that the photoinitiator generates an acid when irradiated with ultraviolet rays, and the protonic acid is used as a catalyst to polymerize a curable monomer. The point is that it is a resist. The second feature is that it has very high transparency in the visible light region.

As a third feature, the curable monomer contained in the transparent photosensitive resin has a relatively small molecular weight before curing, so cyclopentanone, propylene glycol methyl ether acetate (PEGMEA), gamma butyl lactone (GBL), isobutyl Since it dissolves very well in solvents such as ketone (MIBK), it is easy to form a thick film.

The fourth feature is that it has very good light transmittance even at wavelengths in the near-ultraviolet region, so that even a thick film can transmit ultraviolet rays. A fifth feature is that, since each of the features described above is provided, a pattern with a high aspect ratio of 3 or more can be formed. The sixth feature is that since there are many functional groups in the curable monomer, it becomes a very high-density crosslink after curing, and is very stable both thermally and chemically. . Therefore, processing after pattern formation is also facilitated.

However, in this embodiment, the above-mentioned chemically amplified photoresist (trade name "SU-8") was used as the transparent photosensitive resin layer 41, but it is not limited to this, that is, it has the same characteristics. Any photocurable material may be used.

In addition, in the transmissive region forming step of FIG. 10D, development processing is performed on the transparent photosensitive resin layer 41 after exposure. That is, the transparent photosensitive resin layer 41 is developed, and then thermally annealed (thermally annealed) under the conditions of 120 to 150 [° C.] and 30 to 60 [minutes] to form the transparent photosensitive resin layer. 41, a plurality of partitioned light transmission regions 40 are formed. For example, when the first transparent substrate 21 is a glass substrate, the conditions are desirably 150 [° C.] and 30 minutes.

The space width (light shielding pattern width) between the light transmission regions 40 formed here is 5 [μm] as described above. Further, the refractive index of the light transmission region 40 when formed with the above "SU-8" is 1.5 to 1.6.

10F, the second transparent substrate 22 having the transparent conductive film 32 is arranged on the light transmission region 40. As shown in FIG. The second transparent substrate 22 is fixed to the outer periphery of the first transparent substrate 21 with an adhesive (not shown). The adhesive used for this fixation may be either thermosetting or UV curable.

The method of manufacturing the light direction control element 11 of Examples 1 and 2 is the same as the manufacturing method described above, except that the dam forming step is not included. That is, the transparent substrate installation process is performed following the transmission area formation process. Furthermore, in the resin layer forming step, the resin layer 80 is formed along the outermost periphery of the pattern of the light transmission regions 40 .

Differences from the third embodiment will be described. FIG. 11 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the dam 85 is located not only between the surface of the resin layer 80 having no injection holes 81 and exhaust holes 82 and the first square pattern of the light transmission region 40, but also between the injection holes of the resin layer 80. It is also formed between the surface having 81 and the buffer region 90 and between the surface having the exhaust holes 82 of the resin layer 80 and the buffer region 90 .

The dam 85 is provided with openings so as not to block the injection hole 81 and the exhaust hole 82 . With such a shape of the dam 85, the beam direction control element 11 of this embodiment can further enhance the effect of narrowing the frame. In addition, the buffer regions 90 and 91 can be narrowed while increasing the injection speed of the electrophoresis element 60 .

Differences from the second embodiment will be described. FIG. 12 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the buffer region 90 is provided between the entire surface of the resin layer 80 and the first square pattern of the light transmission regions 40 . The width in the Y-axis direction of the portion of the buffer region 90 that contacts the surface of the resin layer 80 that does not have the injection hole 81 and the exhaust hole 82 is, for example, about 1 to 10 [mm].

When the electrophoresis element 60 is injected from the injection hole 81 , the electrophoresis element 60 spreads in the Y-axis direction at the portion of the buffer region 90 that is in contact with the surface of the resin layer 80 having the injection hole 81 . After that, the electrophoresis element 60 spreads in the X-axis direction of the electrophoresis element injection region from the portion of the electrophoresis element injection region in contact with the buffer region 90 .

Furthermore, the electrophoresis element 60 spreads in the X-axis direction at the portion of the buffer region 90 that is in contact with the surface of the resin layer 80 that does not have the injection hole 81 and the exhaust hole 82 . After that, the electrophoresis element 60 spreads in the Y-axis direction of the electrophoresis element injection region from that part.

With such a shape of the buffer region 90 , the beam direction control 11 of this embodiment can further increase the injection speed of the electrophoresis element 60 .

Differences from the fifth embodiment will be described. FIG. 13 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the beam steering element 11 has a dam 85 . The dam 85 is formed between all surfaces of the resin layer 80 and the buffer region 90 . The dam 85 is provided with openings so as not to block the injection hole 81 and the exhaust hole 82 .

By providing the dam 85 in this way, the light beam direction control element 11 of the present embodiment can increase the injection speed of the electrophoresis element 60 and prevent the resin from entering the electrophoresis element injection region. You can get the effect of narrowing the frame. Also, the narrowing of the buffer region 90 can be realized.

Differences from the first embodiment will be described. FIG. 14 is a plan view showing an example of the beam direction control element 11 before the electrophoresis element 60 is injected. In this embodiment, the width of the buffer region 90 in the Y-axis direction is larger than the width of the injection hole 81 in the Y-axis direction, but smaller than the width of the surface of the resin layer 80 having the injection hole 81 in the Y-axis direction.

Also, in this embodiment, the beam direction control element 11 has dams 85 formed between each surface of the resin layer 80 and the first square pattern of the light transmission regions 40 . However, the dam 85 is provided with an opening so as not to block the buffer region 90 and the injection hole 81 .

Although the light beam direction control element 11 of the present embodiment is provided with the buffer region 90, its area is small. Therefore, although the injection speed of the electrophoresis element 60 is improved, the region filled with the electrophoresis element 60 is reduced. This makes it possible to further narrow the frame. In addition, since the dam 85 can block the resin from all directions of the resin layer 80, it is possible to prevent the resin from entering the electrophoresis element injection region. Further, the dam 85 realizes narrowing of the frame.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. A person skilled in the art can easily change, add, or convert each element of the above-described embodiments within the scope of the present disclosure. A part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

Differences from the first embodiment will be described. FIG. 16 is a cross-sectional view showing an example of a light beam direction control element in a narrow-field mode (narrow-field state). In the light direction control element of Example 1, the transparent conductive films 31 and 32 are in contact with the electrophoretic element 60 . On the other hand, the light direction control element 11 of this embodiment has a first transparent protective film 100 and a second transparent protective film 101 .

A first transparent protective film 100 is provided between the transparent conductive film 31 and the electrophoretic element 60 . A second transparent protective film 101 is provided between the transparent conductive film 32 and the electrophoretic element 60 . Specifically, for example, the first transparent protective film 100 is arranged so as to cover the main surface 31 a of the transparent conductive film 31 . Also, the second transparent protective film 101 is arranged so as to cover the main surface 32 a of the transparent conductive film 32 .

Note that the first transparent protective film 100 does not have to cover the entire main surface 31a of the transparent conductive film 31 as long as the main surface 31a and the electrophoretic element 60 are not in contact with each other. Specifically, for example, the first transparent protective film 100 is a transparent protective film pattern that is arranged only in a region on the +Z-axis direction of the upper surface 60a of the electrophoretic element 60 among the regions on the main surface 31a. may Similarly, the second transparent protective film 101 does not have to cover the entire main surface 32a of the transparent conductive film 32, as long as the main surface 32a and the electrophoretic element 60 are not in contact with each other. Specifically, for example, the second transparent protective film 101 is a transparent protective film pattern arranged only in a region on the −Z-axis direction of the lower surface 60b of the electrophoretic element 60 among the regions on the main surface 32a. There may be.

As a constituent material of the first transparent protective film 100, SiO2, Si3N4, or the like can be used, and SiO2 is used in this embodiment. The same applies to the second transparent protective film 101 as well. In the light direction control element 11 of this embodiment, the transparent conductive film 31 and the transparent conductive film 32 are covered with the first transparent protective film 100 and the second transparent protective film 101, respectively. Also, the effect that the electrophoretic particles 61 do not adhere to the surface of the transparent conductive film 32 is obtained.

11 light beam direction control element 21 transparent substrate 22 transparent substrate 30 conductive light shielding film pattern 31 transparent conductive film 32 transparent conductive film 40 light transmission region 60 electrophoretic element 61 electrophoretic particles 62 dispersion medium 80 resin layer 81 injection hole 82 exhaust hole 85 dam 90 buffer region 91 buffer region 100 first transparent protective film 101 second transparent protective film

Claims (6)

a first transparent substrate;
a second transparent substrate arranged to face the first transparent substrate;
a first electrode formed on a first surface of the first transparent substrate facing the second transparent substrate;
a second electrode formed on a second surface of the second transparent substrate facing the first transparent substrate;
a light shielding pattern sandwiched between the first electrode and the second electrode and into which colored electrophoretic particles and a dispersion medium are injected;
a plurality of light transmission regions disposed between the first transparent substrate and the second transparent substrate and having sidewalls surrounded by the light shielding pattern ;
a resin layer disposed between the first transparent substrate and the second transparent substrate, surrounding an outer periphery of the light-transmitting region pattern composed of the plurality of light-transmitting regions, and having a sealed first opening;
The first buffer region is sandwiched between the surface of the resin layer having the first opening and the light transmission region pattern, and includes a first buffer region into which the colored electrophoretic particles and the dispersion medium are injected. A light beam direction control element for
The resin layer has a sealed second opening on a surface different from the surface having the first opening,
The light direction control element is
a second buffer region sandwiched between the surface of the resin layer having the second opening and the light transmission region pattern, into which the colored electrophoretic particles and the dispersion medium are injected;
a first dam sandwiched between a surface of the resin layer that does not have the first opening and the second opening and the light transmission region pattern;
A light direction control element, wherein the electric potential of the first electrode and/or the second electrode is controlled to control the state of dispersion/concentration of the colored electrophoretic particles in the light shielding pattern. A light beam direction control element according to claim 1,
a second dam sandwiched between the surface of the resin layer having the first opening and the first buffer region;
a third dam sandwiched between the surface of the resin layer having the second opening and the second buffer region;
The second dam has an opening that overlaps with the first opening,
The light direction control element , wherein the third dam has an opening that overlaps with the second opening . a first transparent substrate;
a second transparent substrate arranged to face the first transparent substrate;
a first electrode formed on a first surface of the first transparent substrate facing the second transparent substrate;
a second electrode formed on a second surface of the second transparent substrate facing the first transparent substrate;
a light shielding pattern sandwiched between the first electrode and the second electrode and into which colored electrophoretic particles and a dispersion medium are injected;
a plurality of light transmission regions disposed between the first transparent substrate and the second transparent substrate and having sidewalls surrounded by the light shielding pattern;
a resin layer disposed between the first transparent substrate and the second transparent substrate, surrounding an outer periphery of the light-transmitting region pattern composed of the plurality of light-transmitting regions, and having a sealed first opening;
The first buffer region is sandwiched between the surface of the resin layer having the first opening and the light transmission region pattern, and includes a first buffer region into which the colored electrophoretic particles and the dispersion medium are injected. A beam direction control element,
The resin layer has a sealed second opening on a surface different from the surface having the first opening,
The light direction control element is
a second buffer region sandwiched between the surface of the resin layer having the second opening and the light transmission region pattern, into which the colored electrophoretic particles and the dispersion medium are injected;
The colored electrophoretic particles and the dispersion medium are sandwiched between a first surface of the resin layer different from the surface having the first opening and the surface having the second opening, and the light transmission region pattern. an implanted third buffer region;
a fourth dam sandwiched between the surface of the resin layer having the first opening and the first buffer region;
a fifth dam sandwiched between the surface of the resin layer having the second opening and the second buffer region;
a sixth dam sandwiched between the first surface of the resin layer and the third buffer region;
A light direction control element, wherein the electric potential of the first electrode and/or the second electrode is controlled to control the state of dispersion/concentration of the colored electrophoretic particles in the light shielding pattern. A light beam direction control element according to claim 3,
a seventh dam sandwiched between the surface of the resin layer having the first opening and the light transmission area pattern;
A light beam direction control element, comprising: a surface of the resin layer different from the surface having the first opening, and an eighth dam sandwiched between the light transmission region pattern. The light direction control element according to claim 1 or 3,
The light beam direction control element , wherein the pattern width of the light transmission region pattern is three times or more the pattern width of the light shielding pattern . The light direction control element according to claim 1 or 3,
a first transparent protective film sandwiched between the first electrode and the light shielding pattern;
and a second transparent protective film interposed between the second electrode and the light shielding pattern .

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