JP7099882B2 - Manufacturing method of ray direction control element, display device, and ray direction control element - Google Patents

Description

The present disclosure relates to a ray direction control element, a display device, and a method for manufacturing a ray direction control element.

Flat panel display devices are used as display devices in various information processing devices such as mobile phones, PDAs (Personal Digital Assistants), ATMs (Automatic Teller Machines), personal computers, etc. In recent years, flat panels with a wide visible range have been used. Display devices have been put into practical use.

Examples of such a flat panel display device include a liquid crystal display device. The liquid crystal display device is equipped with an optical element that adjusts the emission direction of light incident from the back, a backlight that uniformly emits light toward this optical element, and a liquid crystal display that displays images. Configurations with are generally known.

Further, the liquid crystal display device is required to have various light distribution characteristics due to the increase in size and versatility of the display.

In particular, from the viewpoint of information leakage, there is a request to limit the visible range so that it is not seen by others, and a request to prevent light from being emitted in an unnecessary direction. As an optical element that responds to this, an optical film capable of limiting the visible range (or emission range) of the display has been proposed and put into practical use.

However, in the liquid crystal display device using the optical film, when the display is viewed from a plurality of directions at the same time, it is necessary to remove the optical film each time. This imposes complicated processing on the user and causes a loss of time. Therefore, there is an increasing demand for easily realizing each state of a wide visible range and a narrow visible range without taking the trouble of removing it.

Therefore, in response to such a requirement, a light ray direction control element capable of switching the visible range of the display between the wide field of view mode and the narrow field of view mode has been proposed. As a technique relating to such a light ray direction control element, there are US Pat. No. 7,751667 (Patent Document 1) and International Publication No. 2015/122083 (Patent Document 2).

FIG. 16 is a cross-sectional view of the light ray direction control element described in Patent Document 1. The light ray direction control element 611 described in Patent Document 1 is formed on the transparent substrate 621, the transparent conductive film 631 arranged on the main surface 621a of the transparent substrate 621, and the main surface 631a of the transparent conductive film 631 so as to be separated from each other. It has a plurality of transparent pillars 640 and a mixture 660 of a transparent solvent and a light absorbing element arranged between the transparent pillars 640. Further, in the light ray direction control element 611 described in Patent Document 1, a transparent cover 622 having a transparent conductive film 632 on a main surface 622a is arranged on the upper surface 640a side of the transparent pillar 640.

FIG. 17 is a cross-sectional view of the light ray direction control element described in Patent Document 2. The light ray direction control element 711 described in Patent Document 2 includes a first transparent substrate 721, a plurality of conductive light-shielding film patterns 730 arranged apart from each other on the main surface 721a of the first transparent substrate, and each conductivity. A light transmission region 740 formed on the main surface 721a of the first transparent substrate and between the electrophoresis element 760 arranged on the main surface 730a of the light-shielding film pattern 730 and each of the electrophoresis elements 760. Have. Further, in the light ray direction control element 711 described in Patent Document 2, a second transparent substrate 722 having a transparent conductive film 732 on the main surface 722a is arranged on the upper surface 740a side of the light transmission region 740.

US Pat. No. 7,751667 International Publication No. 2015/122083

However, for the light rays passing through the light ray direction control element 1611 described in Patent Document 1, the interface between the transparent substrate 621 and the transparent conductive film 631, the interface between the transparent conductive film 631 and the transparent pillar 640, and the transparent pillar 640. Since light reflection occurs at the interface between the transparent conductive film 632 and the transparent conductive film 632 and the interface between the transparent conductive film 632 and the transparent cover 644, the transmittance is lowered.

Similarly, for light rays passing through the light ray direction control element 711 described in Patent Document 2, the interface between the light transmission region 740 and the transparent conductive film 732, and between the transparent conductive film 732 and the second transparent substrate 722. Since light reflection occurs at the interface of the above, the transmittance is lowered. Therefore, it is an object of the present disclosure to provide a ray direction control element that realizes a high transmittance.

In order to solve the above problems, one aspect of the present disclosure adopts the following configuration. The light ray direction control element is formed on a first transparent substrate, a second transparent substrate arranged to face the first transparent substrate, and a first surface of the first transparent substrate facing the second transparent substrate. , A first conductive film pattern having an opening, a second conductive film pattern formed on the second surface of the second transparent substrate facing the first transparent substrate and having an opening, and the first conductive film pattern. An electrophoretic element sandwiched between the second conductive film pattern and a light-shielding electrophoretic particle having a surface charge and a translucent dispersion medium, the first transparent substrate and the second transparent substrate. The first conductive film pattern and the second conductive film pattern are sandwiched between at least a part of the opening of the first conductive film pattern and at least a part of the opening of the second conductive film pattern. It is characterized by having a plane parallel to the above and including a plurality of light transmitting regions surrounded by a side wall of the electrophoretic element.

According to the present disclosure, it is possible to provide a ray direction control element that realizes a high transmittance.

It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 1. FIG. It is sectional drawing which shows an example of the ray direction control element of the wide field of view mode (wide field of view state) in Example 1. FIG. It is a graph which shows the simulation result of the front transmittance for each wavelength of the ray direction control element of Example 1 and the ray direction control element of the related technique. It is a top view which shows an example of the ray direction control element in Example 1. FIG. It is a top view which shows an example of the ray direction control element in Example 1. FIG. It is a top view which shows an example of the ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (transparent conductive film forming process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (transparent conductive film forming process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (photosensitive resin laminating process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (exposure light irradiation process and position control process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (transparent substrate installation process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is explanatory drawing which shows an example of the process (phoresis element filling process) of the manufacturing method of the light ray direction control element in Example 1. FIG. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 2. FIG. It is explanatory drawing which shows an example of the process (irradiation formation process) of the manufacturing method of the light ray direction control element in Example 2. FIG. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 3. FIG. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 3. FIG. It is explanatory drawing which shows an example of the process (transparent conductive film forming process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (insulating film stack formation process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (photosensitive resin laminating process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (exposure light irradiation process and position control process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (transmission area forming process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (transparent substrate installation process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is explanatory drawing which shows an example of the process (phoresis element filling process) of the manufacturing method of the light ray direction control element in Example 3. FIG. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 4. FIG. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 4. FIG. It is explanatory drawing which shows an example of the display device which includes the ray direction control element in Example 5. FIG. It is sectional drawing which shows an example of the ray direction control element in a related technique. It is sectional drawing which shows an example of the ray direction control element in a related technique. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 6. It is sectional drawing which shows an example of the ray direction control element of the narrow field of view mode (narrow field of view state) in Example 6. It is explanatory drawing which shows an example of the process (transparent conductive film forming process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (insulating film stack formation process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (step of removing a part of an insulating film) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (photosensitive resin laminating process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (exposure light irradiation process and position control process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (transmission area forming process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (transparent substrate installation process) of the manufacturing method of the light ray direction control element in Example 6. It is explanatory drawing which shows an example of the process (phoresis element filling process) of the manufacturing method of the light ray direction control element in Example 6.

Hereinafter, embodiments will be described with reference to the accompanying drawings. It should be noted that this 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 configurations in each figure. Also, the shapes drawn in the drawings do not always match the actual dimensions and ratios.

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

The light ray direction control element 11 includes a first transparent substrate 21, a transparent conductive film pattern 31, a light transmitting region 40, an electrophoresis element 60, a second transparent substrate 22, and a transparent conductive film pattern 32. The transparent conductive film pattern 31 is formed on the surface (main surface) 21a of the first transparent substrate 21. The transparent conductive film pattern 32 is formed on the surface (main surface) 22a of the second transparent substrate 22. The first transparent substrate 21 and the second transparent substrate 22 have a main surface 31a of the transparent conductive film pattern 31.
And the main surface 32a of the transparent conductive film pattern 32 are arranged so as to face each other.

The electrophoresis element 60 is arranged so as to be sandwiched between the main surface 31a of the transparent conductive film pattern 31 and the main surface 32a of the transparent conductive film pattern 32. The electrophoresis element 60 includes an electrophoresis particle 61 and a dispersion medium 62. Further, in the examples of FIGS. 1 and 2, the entire upper surface 60a of the electrophoresis element 60 is in contact with the transparent conductive film pattern 32, and the entire lower surface 60b of the electrophoresis element 60 is in contact with the transparent conductive film pattern 31. ..

The cross sections of the light transmission region 40 and the dispersion medium 62 are shown without hatching for the sake of clarity. The light transmission region 40 is arranged in the voids of the first transparent substrate 21, the transparent conductive film pattern 31, the second transparent substrate 22, and the transparent conductive film pattern 32.

The narrow field of view mode shown in FIG. 1 is realized by dispersing the electrophoresis particles 61 in the electrophoresis element 60 arranged in the gaps of the light transmission regions 40 in the dispersion medium 62. Thereby, the spread of the light rays transmitted from the bottom to the top in the drawing is limited by the electrophoresis element 60 between the first transparent substrate 21 and the second transparent substrate 22. As a result, the viewing angle becomes narrower when compared before and after transmission, and the narrow field of view mode is set. On the other hand, the wide field mode shown in FIG. 2 is realized by concentrating the electrophoretic particles 61 in the vicinity of the transparent conductive film pattern 31. For example, the electrophoretic particles 61 are collected in the vicinity of the transparent conductive film pattern 31 by setting the relative potential of the transparent conductive film pattern 31 with respect to the transparent conductive film pattern 32 to have a polarity opposite to the surface charge of the electrophoretic particles 61. .. Thereby, the spread of the light rays transmitted from the bottom to the top in the drawing is hardly limited 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 the viewing angle when compared before and after transmission, and the wide field of view mode is established.

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

Hereinafter, the configuration contents when the surface charge of the electrophoretic particle 61 is a negative charge (−) will be described. Even when the surface charge of the electrophoresis particles 61 is a positive charge (+), it can be similarly dealt with by reversing the polarity of the conductive light-shielding film pattern 30.

The transparent conductive film 631 of FIG. 16 is arranged so as to cover the main surface 621a of the transparent substrate 621, but in the example of FIG. 1, the transparent conductive film pattern 31 and the transparent conductive film pattern 32 have an opening. It is formed, and a light transmission region 40 is arranged in the opening. In particular, in the example of FIG. 1, the light transmitting region 40 is not in contact with the main surface 31a of the transparent conductive film pattern 31 and the main surface 32a of the transparent conductive film pattern 32.

As a result, among the light rays incident on the light transmitting region 40, the light passes through an interface having a high reflectance (for example, an interface between the light transmitting region and the transparent conductive film and an interface between the transparent conductive film and the transparent substrate). It is possible to increase the proportion of light rays that are not. As a result, it is possible to realize the light ray direction control element 11 having a high transmittance.

FIG. 3 is a graph showing the simulation results of the front transmittance for each wavelength in the light ray direction control element 11 of this embodiment and the light ray direction control element 711 described in Patent Document 2, which is a related technique. Here, the front means that the viewpoint is placed in the normal direction with respect to the surface of the substrate. FIG. 3 shows the transmittance 301 in the light ray direction control element 11 of this embodiment and the transmittance 302 in the light ray direction control element 711 of FIG. The simulation results of FIG. 3 show that the transmittance of the ray direction control element 11 is about 3 to 8% higher than that of the ray direction control element 711 at all wavelengths.

Next, the configuration of the light ray 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 (PolyCarbonate), PEN (PolyEthylene Naphthalate), or COT (CycloOlefin Polymer). The same applies to the second transparent substrate 22.

The film thickness of the transparent conductive film pattern 31 is appropriately in the range of 10 [nm] to 1000 [nm], and is 50 [nm] in this embodiment. Further, as a constituent material of the transparent conductive film pattern 31, ITO (Indium Tin Oxide), ZnO, IGZO (Indium Gallium Zinc Oxide), or the like can be adopted, which is ITO in this embodiment. The same applies to the transparent conductive film pattern 32.

Further, a light transmitting region 40 is formed at a position complementary to the transparent conductive film pattern 31 on the first transparent substrate 21. As shown in FIG. 1, the “complementary position” here means a positional relationship in which the transparent conductive film pattern 31 and the light transmitting region 40 are alternately arranged on the main surface of the first transparent substrate 21. It is preferable that the transparent conductive film pattern 31 and the light transmitting region 40 are arranged so as not to intersect each other (without overlapping). The same applies to the positional relationship between the transparent conductive film pattern 32 on the second transparent substrate 22 and the light transmitting region 40.

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. Further, 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.

As described above, the electrophoresis element 60, which is a mixture of the electrophoresis particles 61 and the dispersion medium 62, is arranged between the light transmission regions 40.

Next, three examples shown in FIGS. 4 to 6 will be described as examples of arrangement of each light transmission region 40 and the electrophoresis element 60. 4 to 6 are examples of plan views of the light ray direction control element 11. In FIGS. 4 to 6, the transparent conductive film pattern 32 and the second transparent substrate 22 are not shown.

In the example of the structure of the square pattern of FIG. 4 (first example), the square light transmission regions 40 have a planar shape arranged in a grid pattern, and a plurality of electrophoresis elements 60 (transparent conductive film patterns 31 to 32) are provided. It forms a square grid that fills the gaps in the light transmission region 40. That is, the light ray direction control element 11 in this case is formed so 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 (light). The light-shielding film pattern width 41b and the light-shielding film pattern width 42b, which correspond to the width between the transmission regions 40), are also formed to be equal to each other.

In the example of the structure of the rectangular pattern of FIG. 5 (second example), the planar shapes of the light transmitting region 40 and the electrophoretic element 60 (transparent conductive film patterns 31 to 32) form a rectangular grid shape. That is, the light ray direction control element 11 in this case is formed so that the light transmission pattern width 42a is longer than the light transmission pattern width 41a. On the other hand, the lengths of the light-shielding film pattern width 41b and the light-shielding film pattern width 42b are formed to be equal to each other.

In the example of the structure of the stripe pattern of FIG. 6 (third example), the planar shapes of the light transmission region 40 and the electrophoresis element 60 (transparent conductive film patterns 31 to 32) form a stripe shape. That is, in the light ray direction control element 11 in this case, the light transmission pattern width 41a by each light transmission region 40 and the light shielding film pattern width 41b of the electrophoresis element 60 are arranged so as to be alternately continuous. In the case of the stripe pattern, the plurality of transparent conductive film patterns 31 to 32 are electrically connected and driven outside (not shown).

Hereinafter, each step of the manufacturing method of the light ray direction control element 11 in this embodiment will be described with reference to FIGS. 7A to 7F. First, as shown in FIG. 7A, a transparent conductive film pattern 31 is formed on the surface (main surface) of the first transparent substrate 21 (transparent conductive film pattern forming step). Next, as shown in FIG. 7B, 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 pattern 31 is formed (photosensitivity). Sex resin laminating process). The transparent photosensitive resin layer 41 is a member that becomes a light transmitting region 40 through a transmission region forming step described later.

Next, as shown in FIG. 7C, the transparent photosensitive resin layer 41 is exposed by irradiating the transparent photosensitive resin layer 41 with the exposure light 75 through the photomask 70 provided with the mask pattern 71 (exposure light irradiation step). ). In this exposure light irradiation step, the alignment marks (not shown) formed on the first transparent substrate 21 and the photomask 70 are used so that the position of the mask pattern 71 overlaps with the transparent conductive film pattern 31. Control is performed to adjust the positions of the photomask 70 and the first transparent substrate 21 (position control step).

Next, the exposed transparent photosensitive resin layer 41 is subjected to a developing process to form a plurality of light transmitting regions 40 separated from each other as shown in FIG. 7D (transmission region forming step).

Subsequently, using the alignment marks (not shown) formed on the second transparent substrate 22 and the first transparent substrate 21, the transparent conductive film is formed on the surface of the light transmitting region 40 as shown in FIG. 7E. A second transparent substrate 22 provided with the pattern 32 is installed (transparent substrate installation step).

Then, as shown in FIG. 7F, the electrophoresis element 60 is filled in the voids formed by the transparent conductive film pattern 31, the light transmitting region 40, and the transparent conductive film pattern 32 (electrophoresis element filling step).

In the above description based on FIGS. 7A to 7F, a method of executing the migration element filling step after the transparent substrate installation step has been shown, but in these two steps, even if the order is reversed, the light beam is similarly applied. The direction control element 11 can be manufactured.

That is, after carrying out the same as the description based on FIGS. 7A to 7D, the migration 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, You may carry out the transparent substrate installation step of installing the second transparent substrate 22 provided with the transparent conductive film pattern 32 on the surfaces of the light transmission region 40 and the electrophoresis element 60.

Here, the exposure light 75 used for the exposure is parallel light in the stacking direction (direction in which the transparent photosensitive resin layer 41 and the like are laminated). Further, a UV light source is used as the light source of the exposure light 75, and in the exposure light irradiation step in the present embodiment, for example, UV light having a wavelength of 365 [nm] is irradiated as the exposure light 75.

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, one of a film forming method such as a slit die coater, a wire coater, an applicator, a dry film transfer, spray coating, or screen printing is used. Can be done. By such a film forming method, in this example, the thickness of the transparent photosensitive resin layer 41, which is appropriate in the range of 30 [μm] to 300 [μm], is formed to be 60 [μm].

Further, 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 Microchem Co., Ltd. can be adopted. The features of this transparent photosensitive resin are as follows.

The first feature is the negative of an epoxy-based (specifically, a glycidyl ether derivative of bisphenol A novolac) in which a photoinitiator generates an acid when irradiated with ultraviolet rays and polymerizes a curable monomer using this protonic acid as a catalyst. The point is that it is a resist. The second feature is that it has a very transparent property in the visible light region.

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

The fourth feature is that the light transmission is very good even at wavelengths in the near-ultraviolet region, so that even a thick film can transmit ultraviolet rays. The fifth feature is that it is possible to form a pattern having a high aspect ratio of 3 or more because it has each of the above-mentioned features. The sixth feature is that since the curable monomer contains many functional groups, it becomes a very high-density crosslink after curing and is very stable both thermally and chemically. .. Therefore, processing after pattern formation becomes easy.

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

In the transmission region forming step of FIG. 7D, the transparent photosensitive resin layer 41 is subjected to a developing process after exposure. That is, the transparent photosensitive resin layer 41 is developed, and then heat annealing (heat annealing treatment) is performed under the conditions of 120 to 150 [° C.] and 30 to 60 [minutes] to obtain the transparent photosensitive resin layer. A plurality of light transmission regions 40 are formed in 41. For example, when the first transparent substrate 21 is a glass substrate, it is desirable that the conditions are 150 [° C.] and 30 minutes.

The space width (light-shielding film 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 in the case of being formed by the above "SU-8" is 1.5 to 1.6.

In the transparent substrate installation step of FIG. 7F, the second transparent substrate 22 provided with the transparent conductive film pattern 32 is arranged on the light transmitting region 40. The second transparent substrate 22 is fixed at the outer peripheral portion of the first transparent substrate 21 with an adhesive (not shown). As the adhesive used for this fixing, either thermosetting or UV curable may be used.

As described above, in the light ray direction control element 11 of the present embodiment, the transparent conductive film pattern 31 and the transparent conductive film pattern 32 are formed so as to have an opening instead of a series of shapes, and the opening and the light transmission are formed. Regions 40 are in contact. In particular, in the example of FIG. 1, the light transmission region 40 is in contact with only the opening thereof, and is not in contact with the main surface 31a of the transparent conductive film pattern 31 and the main surface 32a of the transparent conductive film pattern 32.

As a result, among the light rays incident on the light transmitting region 40, the light passes through an interface having high transmittance (for example, an interface between the light transmitting region and the transparent conductive film and an interface between the transparent conductive film and the transparent substrate). It is possible to increase the proportion of light rays that are not used, and it is possible to realize a light beam direction control element 11 having a high transmittance.

Hereinafter, the light ray direction control element 11 of this embodiment will be described. Differences from the first embodiment will be described. FIG. 8 is a cross-sectional view showing an example of a light ray direction control element in a narrow field of view mode (narrow field of view state). In the light ray direction control element 11 of the second embodiment, a conductive light-shielding film pattern 30 is formed on the surface (main surface) 21a of the first transparent substrate 21 instead of the transparent conductive film pattern 31.

As a constituent material of the conductive light-shielding film pattern 30, a light-shielding conductive material such as aluminum, chromium, copper, or chromium oxide can be preferably used, and in this embodiment, aluminum is used. The film thickness of the conductive light-shielding film pattern 30 is preferably in the range of 10 [nm] to 1000 [nm], and is 300 [nm] in this embodiment.

In the manufacturing methods shown in FIGS. 7A to 7F, the light ray direction control element 11 of this embodiment can be manufactured by using the conductive light-shielding film pattern 30 instead of the transparent conductive film pattern 31. Hereinafter, another example of the manufacturing method of the light ray direction control element 11 of this embodiment will be described.

FIG. 9 is an explanatory diagram showing an example of an irradiation forming step in the manufacturing process of the light ray direction control element 11. In the manufacturing process of the light ray direction control element 11 of the present embodiment, the irradiation forming step shown in FIG. 9 may be adopted instead of the exposure light irradiation step and the transmission region forming step of the manufacturing process in the first embodiment. In the exposure light irradiation step, the transparent photosensitive resin layer 41 is patterned by irradiating the exposure light 75 from the back surface side of the first transparent substrate 21 using the conductive light-shielding film pattern 30 as a photomask. Irradiation formation step).

Parallel light is used as the exposure light 75 used for the above exposure, and a UV light source is used as the light source. In this embodiment, UV light having a wavelength of 365 [nm] was irradiated as the exposure light 75. The exposure amount preferably in the range of 100 [mJ / cm ² ] to 1000 [mJ / cm ² ] was set to 200 [mJ / cm ² ] here as well.

As described above, by using the conductive light-shielding film pattern 30 as the photomask, in addition to the effect in the first embodiment, the position control step of adjusting the positions of the photomask 70 and the first transparent substrate 21 in the first embodiment. Even if this is not performed, the relative positions of the light transmitting region 40 and the conductive light-shielding film pattern 30 naturally have a complementary relationship. Further, even if the position control step is not performed, the upper surface 60a of the electrophoresis element 60 is in contact with the transparent conductive film pattern 32 as an electrode, and the entire lower surface 60b of the electrophoresis element 60 is in contact with the conductive light-shielding film pattern 30 as an electrode. As described above, the light ray direction control element 11 can be manufactured.

Hereinafter, the light ray direction control element 11 of this embodiment will be described. Differences from the first embodiment will be described. 10 and 11 are cross-sectional views showing an example of the light ray direction control element 11 in the narrow field of view mode (narrow field of view state).

The light ray direction control element 11 of FIG. 10 further includes an insulating film 81 and an insulating film 82. The insulating film 81 is formed in a layer on the surface (main surface) 21a of the first transparent substrate 21 so as to cover the transparent conductive film pattern 31. Further, the insulating film 82 is formed in a layer on the surface (main surface) 22a of the second transparent substrate 22 so as to cover the transparent conductive film pattern 32. The light transmission region 40 and the electrophoresis element 60 are arranged at positions sandwiched between the insulating film 81 and the insulating film 82. Examples of the constituent materials of the insulating film 81 and the insulating film 82 include silicon oxide and silicon nitride.

In the light ray direction control element 11 of FIG. 11, a conductive light-shielding film pattern 30 is formed in place of the transparent conductive film pattern 31 of FIG. The details of the conductive light-shielding film pattern 30 are as described in Example 2.

An example of a method for manufacturing the light ray direction control element of FIG. 10 will be described with reference to FIGS. 12A to 12G. Since the transparent conductive film pattern forming step of FIG. 12A is the same as the transparent conductive film pattern forming step of FIG. 7A, the description thereof will be omitted. In FIG. 12B, an insulating film 81 is formed on the first transparent substrate 21 on which the transparent conductive film pattern 31 is formed so as to cover the transparent conductive film pattern 31 by using a method such as CVD (Chemical Vapor Deposition). (Insulating film laminating process).

Next, in FIG. 12C, as in FIG. 7B, the transparent photosensitive resin layer 41 as a negative photoresist film is formed on the main surface side of the first transparent substrate 21 on which the transparent conductive film pattern 31 and the insulating film 81 are formed. (Photosensitive resin laminating step).

Next, in FIG. 12D, the transparent photosensitive resin layer 41 is exposed by irradiating the transparent photosensitive resin layer 41 with the exposure light 75 through the photomask 70 provided with the mask pattern 71, as in FIG. 7C. Exposure light irradiation step). In this exposure light irradiation step, control is performed to adjust the positions of the photomask 70 and the first transparent substrate 21 so that the position of the mask pattern 71 overlaps with the transparent conductive film pattern 31 (position control step).

Next, in FIG. 12E, the transparent photosensitive resin layer 41 exposed in the same manner as in FIG. 7D is subjected to a developing process to form a plurality of light transmitting regions 40 separated from each other as shown in FIG. 12E (as shown in FIG. 12E). Transmission region forming step).

Subsequently, in FIG. 12F, a second transparent substrate 22 provided with the transparent conductive film pattern 32 and the insulating film 82 is installed on the surface of the light transmission region 40 (transparent substrate installation step). Then, as shown in FIG. 12G, the electrophoresis element 60 is filled in the voids formed by the transparent conductive film pattern 31, the light transmitting region 40, and the transparent conductive film pattern 32 (electrophoresis element filling step).

The method for manufacturing the light ray direction control element 11 in FIG. 11 is the same as the method for manufacturing the light ray direction control element 11 in FIG. 10, but FIG. 8 is shown in Example 2 instead of the exposure light irradiation step and the transmission region forming step. The irradiation forming step (back exposure) described in use may be performed.

In the light ray direction control element 11 of this embodiment, the insulating characteristics between the electrodes are improved by arranging the insulating film on the surface of the transparent conductive film (or the conductive light-shielding film pattern) which is an electrode. Further, it is possible to suppress the adhesion of the electrophoretic particles 61 to the electrode surface. Therefore, it is possible to suppress the deterioration of the electrophoresis element 60 caused by the adhesion of the electrophoresis particles 61 to the electrode surface. In addition, a higher electric field can be applied, and the responsiveness is improved.

Hereinafter, the light ray direction control element 11 of this embodiment will be described. Differences from the first embodiment will be described. FIG. 13 is a cross-sectional view showing an example of the light ray direction control element 11 in the narrow field of view mode (narrow field of view state). In the light ray direction control element 11 of FIG. 13, the pattern width A of the transparent conductive film pattern 31 and the transparent conductive film pattern 32 is larger than the width B of the electrophoresis element 60.

Specifically, in this embodiment, the width of the light transmitting region 40 is 20 [μm], and the width B of the electrophoresis elements 60 between the light transmitting regions 40 is 5 [μm]. The pattern width A of the film pattern 31 and the transparent conductive film pattern 32 is more than 5 [μm] and less than 25 [μm], and for example, 6 [μm] is suitable. Further, the protrusion widths C and D of the transparent conductive film pattern 31 and the transparent conductive film pattern 32 from the electrophoresis element 60 are, for example, both more than 0 [μm] and less than 20 [μm], for example, 1 [μm]. Is preferable.

The method for manufacturing the light ray direction control element 11 in FIG. 13 is, for example, the same as the manufacturing method for the first embodiment. In the light ray direction control element 11 of FIG. 13, since the pattern width A is larger than the width B of the electrophoresis element 60, even if some positional deviation occurs in the position control step, the upper surface 60a of the electrophoresis element 60 is an electrode. The light ray direction control element 11 can be manufactured so that the entire lower surface 60b of the electrophoresis element 60 is in contact with the transparent conductive film pattern 31 which is an electrode on a certain transparent conductive film pattern 32.

FIG. 14 is a cross-sectional view showing an example of the light ray direction control element 11 in the narrow field of view mode (narrow field of view state). In the light ray direction control element 11 of FIG. 14, the width A'of the transparent conductive film pattern 31 is larger than the pattern width A of the transparent conductive film pattern 32, which is different from the light ray direction control element 11 of FIG.

Specifically, for example, when the pattern width A of the transparent conductive film pattern 32 is 5 [μm], the pattern width A'of the transparent conductive film pattern 31 is preferably 6 [μm] to 10 [μm]. The method for manufacturing the light ray direction control element 11 in FIG. 14 is, for example, the same as the manufacturing method for the first embodiment.

In the light ray direction control element 11 of FIG. 14, the pattern width A'of the transparent conductive film pattern 31 is larger than the pattern width A of the transparent conductive film pattern 32. Misalignment can also be tolerated. That is, even if some misalignment occurs in the process of installing the transparent substrate, the transparent conductive film pattern 32 in which the upper surface 60a of the electrophoresis element 60 is an electrode and the entire lower surface 60b of the electrophoresis element 60 are electrodes. The ray direction control element 11 can be manufactured so as to be in contact with the pattern 31.

Hereinafter, in this embodiment, an example of a display device including the ray direction control element 11 will be described with reference to FIG. The display device includes, for example, a light ray direction control element 11 bonded by a transparent adhesive layer or the like, and a display unit 100 for displaying an image. In the example of FIG. 15, the light ray direction control element 11 is arranged on the surface (display surface) 100a side of the display unit 100. That is, the opposite surface of the main surface of the first transparent substrate 21 is adhered to the display unit 100. The light ray direction control element 11 in the example of FIG. 15 is the light ray direction control element 11 of FIG. 11 in which the conductive light-shielding film pattern 30 is formed on the first transparent substrate 21 (for example, FIG. 8). It may be a ray direction control element 11).

In the example of FIG. 15, the light ray direction control element 11 is arranged so that the conductive light-shielding film pattern 30 is on the observer side, that is, the transparent conductive film pattern 32 is close to the surface 100a of the display unit 100. By arranging the light ray direction control element 11 in this way, even if optical moire occurs when the relative positions of the transparent conductive film pattern 32 and the light transmission region 40 deviate from each other, the observer can visually recognize the optical moire. It is possible to secure a good display state.

Hereinafter, the light ray direction control element 11 of this embodiment will be described. Differences from the third embodiment will be described. 18 and 19 are cross-sectional views showing an example of the light ray direction control element 11 in the narrow field of view mode (narrow field of view state).

The light ray direction control element 11 of FIG. 18 includes an insulating film pattern 111 and an insulating film pattern 112. The insulating film pattern 111 is formed in a pattern on the surface (main surface) 21a of the first transparent substrate 21. Each element (non-opening portion) of the insulating film pattern 111 covers the element (non-opening portion) of the transparent conductive film pattern 31. Further, the insulating film pattern 112 is formed in a pattern on the surface (main surface) 22a of the second transparent substrate 22. Each element (non-opening portion) of the insulating film pattern 112 covers the element of the transparent conductive film pattern 32. There may be an element of the insulating film pattern 111 that covers a plurality of elements (non-openings) of the transparent conductive film pattern 31.

The light transmission region 40 and the electrophoresis element 60 are formed on the surface (main surface) 21a of the first transparent substrate 21, the insulating film pattern 111, the surface (main surface) 22a of the second transparent substrate 22, and the insulating film pattern 112. It is placed in the position where it is sandwiched. Examples of the constituent materials of the insulating film pattern 111 and the insulating film pattern 112 include silicon oxide and silicon nitride.

In the light ray direction control element 11 of FIG. 19, a conductive light-shielding film pattern 30 is formed in place of the transparent conductive film pattern 31 of FIG. The details of the conductive light-shielding film pattern 30 are as described in Example 2.

An example of a method for manufacturing the light ray direction control element of FIG. 18 will be described with reference to FIGS. 20A to 20H. Since the transparent conductive film pattern forming step of FIG. 20A and the insulating film forming step of FIG. 20B are the same as the transparent conductive film pattern forming step of FIG. 12A and the insulating film forming step of FIG. 12B, the description thereof will be omitted. Next, in FIG. 20C, the insulating film 81 other than the portion covering each element of the transparent conductive film pattern 31 is removed to form the insulating film pattern 111 (partial insulating film removing step).

Next, in FIG. 20D, as in FIG. 7B, a transparent photosensitive resin as a negative photoresist film is formed on the main surface side of the first transparent substrate 21 on which the transparent conductive film pattern 31 and the insulating film pattern 111 are formed. The layers 41 are laminated and formed (photosensitive resin laminating step).

Next, in FIG. 20E, the transparent photosensitive resin layer 41 is exposed by irradiating the transparent photosensitive resin layer 41 with the exposure light 75 through the photomask 70 provided with the mask pattern 71, as in FIG. 7C. Exposure light irradiation step). In this exposure light irradiation step, control is performed to adjust the positions of the photomask 70 and the first transparent substrate 21 so that the position of the mask pattern 71 overlaps with the transparent conductive film pattern 31 (position control step).

Next, in FIG. 20F, the transparent photosensitive resin layer 41 exposed in the same manner as in FIG. 7D is subjected to a developing process to form a plurality of light transmitting regions 40 separated from each other as shown in FIG. 20F (as shown in FIG. 20F). Transmission region forming step).

Subsequently, in FIG. 20G, a second transparent substrate 22 provided with the transparent conductive film pattern 32 and the insulating film pattern 112 is installed on the surface of the light transmission region 40 (transparent substrate installation step). Then, as shown in FIG. 20H, the first transparent substrate 21, the insulating film pattern 111, the second transparent substrate 22, the insulating film pattern 112, the transparent conductive film pattern 31, the light transmitting region 40, and the transparent conductive film pattern 32 are formed. The formed void is filled with the electrophoresis element 60 (electrophoresis element filling step).

The method for manufacturing the light ray direction control element 11 in FIG. 19 is the same as the method for manufacturing the light ray direction control element 11 in FIG. 18, but FIG. 8 is shown in Example 2 instead of the exposure light irradiation step and the transmission region forming step. The irradiation forming step (back exposure) described in use may be performed.

The light ray direction control element 11 of this embodiment is a light ray direction control element having a higher transmittance by patterning an insulating film arranged on the surface of a transparent conductive film (or a conductive light-shielding film pattern) which is an electrode. 11 can be realized.

Although the present embodiment has been described in detail with reference to the attached drawings, the present disclosure is not limited to such a specific configuration, and various changes and equivalents within the scope of the attached claims. It includes the composition of.

11 Ray direction control element, 21 transparent substrate, 22 transparent substrate, 30 conductive light-shielding film pattern, 31 transparent conductive film pattern, 32 transparent conductive film pattern, 40 light transmission region, 60 electrophoretic element, 61, electrophoretic particles, 62 Dispersion medium, 81 insulating film, 82 insulating film, 100 display unit, 111 insulating film pattern, 112 insulating film pattern

Claims (11)

The first transparent board and
A second transparent substrate arranged to face the first transparent substrate and
A first conductive film pattern formed on the first surface of the first transparent substrate facing the second transparent substrate and having an opening, and a first conductive film pattern.
A second conductive film pattern formed on the second surface of the second transparent substrate facing the first transparent substrate and having an opening, and a second conductive film pattern.
An electrophoretic element sandwiched between the first conductive film pattern and the second conductive film pattern, which contains surface-charged light-shielding electrophoretic particles and a translucent dispersion medium.
It is arranged between the first transparent substrate and the second transparent substrate, and is sandwiched between at least a part of the opening of the first conductive film pattern and at least a part of the opening of the second conductive film pattern. A plurality of light transmitting regions having a surface parallel to the first conductive film pattern and the second conductive film pattern and having a side wall surrounded by the electrophoretic element are included.
A light ray direction control element, characterized in that at least one of the light transmitting region and the insulating film is arranged in each of the opening of the first conductive film pattern and the opening of the second conductive film pattern . The ray direction control element according to claim 1.
A light ray direction control element, wherein the first conductive film pattern and the second conductive film pattern are transparent conductive film patterns. The ray direction control element according to claim 1.
The light ray direction control element, wherein the first conductive film pattern is a conductive light-shielding film pattern, and the second conductive film pattern is a transparent conductive film pattern. A display device including the light ray direction control element according to claim 3.
Including a display unit including a display surface for displaying an image,
A display device characterized in that the opposite surface of the second surface of the second transparent substrate is adhered to the display unit. The ray direction control element according to claim 1.
A first insulating film formed on the first surface overlying the first conductive film pattern,
The second surface includes a second insulating film formed over the second conductive film pattern.
The electrophoretic element is a light ray direction control element characterized in that it is sandwiched between the first insulating film and the second insulating film. The ray direction control element according to claim 1.
A ray direction control element characterized in that the pattern widths of the first conductive film pattern and the second conductive film pattern are larger than the width of the electrophoresis element. The light ray direction control element according to claim 6.
A ray direction control element characterized in that the pattern width of one of the first conductive film pattern and the second conductive film pattern is larger than the pattern width of the other. A first conductive film pattern forming step of forming a first conductive film pattern having an opening on the first surface of the first transparent substrate,
A photosensitive resin laminating step of laminating a transparent photosensitive resin layer on the first surface of the first transparent substrate on which the first conductive film pattern is formed.
An exposure light irradiation step of irradiating the laminated transparent photosensitive resin with an exposure light composed of parallel light in the laminated direction.
A transmission region forming step of subjecting the transparent photosensitive resin irradiated with the exposure light to a developing process to form a plurality of light transmitting regions separated from each other.
A second transparent substrate installation step of installing a second transparent substrate having a second conductive film pattern having an opening formed on the second surface so that the second surface faces the plurality of light transmission regions.
Electricity containing surface-charged light-shielding electrophoretic particles and a translucent dispersion medium in the voids formed by the first conductive film pattern, the plurality of light-transmitting regions, and the second conductive film pattern. The migration element filling process for filling the migration element and
A method for manufacturing a light ray direction control element, which comprises. The method for manufacturing a ray direction control element according to claim 8.
The first conductive film pattern is a conductive light-shielding film pattern.
A method for manufacturing a light ray direction control element, which comprises irradiating the exposure light from the opposite surface side of the first surface of the first transparent substrate in the exposure light irradiation step. The ray direction control element according to claim 1.
A first insulating film pattern formed on the first surface so as to cover the non-opening portion of the first conductive film pattern and having an opening portion .
The second surface includes a second insulating film pattern formed by covering the non-opening portion of the second conductive film pattern and having an opening portion .
The electrophoresis element is sandwiched between the first insulating film pattern and the second insulating film pattern.
A light ray direction control element , wherein each of the plurality of light transmission regions is sandwiched between the opening of the first insulating film pattern and the opening of the second insulating film pattern . The first transparent board and
A second transparent substrate arranged to face the first transparent substrate and
A first conductive film pattern formed on the first surface of the first transparent substrate facing the second transparent substrate and having an opening, and a first conductive film pattern.
A second conductive film pattern formed on the second surface of the second transparent substrate facing the first transparent substrate and having an opening, and a second conductive film pattern.
An electrophoretic element sandwiched between the first conductive film pattern and the second conductive film pattern, which contains surface-charged light-shielding electrophoretic particles and a translucent dispersion medium.
It is arranged between the first transparent substrate and the second transparent substrate, and is sandwiched between at least a part of the opening of the first conductive film pattern and at least a part of the opening of the second conductive film pattern. A plurality of light transmitting regions having a surface parallel to the first conductive film pattern and the second conductive film pattern and having a side wall surrounded by the electrophoretic element are included.
The first surface and the surface parallel to the second surface of the plurality of light transmission regions are in contact with the first transparent substrate and the second transparent substrate, or in contact with the insulating film, respectively. Control element.

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