Optical phase modulation element and display device

Abstract

The present invention improves the reflectance of a reflective optical phase modulation element. This optical phase modulation element comprises a liquid crystal layer that adjusts the phase of incident light, a first orientation film and a second orientation film that orient the liquid crystal molecules of the liquid crystal layer, a counter electrode that is disposed in proximity to the second orientation film and applies a drive voltage to the liquid crystal layer, and a plurality of regions that include: a reflecting electrode that is disposed in proximity to the first orientation film and applies a drive voltage to the liquid crystal layer and reflects the incident light transmitted through the counter electrode and the liquid crystal layer; and a reflective film that is disposed between the first orientation film and the reflecting electrode, is formed by laminating a plurality of dielectric layers, and reflects at least some of the incident light transmitted through the liquid crystal layer. The plurality of regions are each provided with a reflective film having a configuration corresponding to the wavelength of the incident light.

Description

Optical phase modulation element and display device

[0001] The present disclosure relates to an optical phase modulation element and a display device.

[0002] Display devices are being used that include an optical phase modulation element that modulates the phase of incident light. This optical phase modulation element is an element that includes a liquid crystal panel and modulates the phase of light based on a control signal. Display devices that use this optical phase modulation element are capable of arbitrarily controlling the focal plane and orientation direction of light, and are therefore expected to be used for three-dimensional video display. Display devices are also being used that utilize a reconstructed image generated by phase modulation according to an image displayed by the optical phase modulation element as illumination light for a light intensity modulation element for video display. As such an optical phase modulation element, a reflective phase modulation element has been proposed, in which a display area is divided into two or more regions, each region is filled with a liquid crystal material having a different refractive index anisotropy, and the phase pattern can be displayed according to the wavelength corresponding to each region (see, for example, Patent Document 1).

[0003] International Publication No. 2022 / 050028

[0004] However, in the above-mentioned conventional technology, since each region has the same film configuration, there is a problem in that the reflectance decreases for incident light of a plurality of wavelengths.

[0005] Therefore, the present disclosure proposes an optical phase modulation element with improved reflectance and a display device using the optical phase modulation element.

[0006] The optical phase modulation element of the present disclosure has a liquid crystal layer that adjusts the phase of incident light, a first alignment film and a second alignment film that align liquid crystal molecules in the liquid crystal layer, a counter electrode arranged close to the second alignment film and applying a drive voltage to the liquid crystal layer, a reflective electrode arranged close to the first alignment film and applying a drive voltage to the liquid crystal layer and reflecting incident light that has passed through the counter electrode and the liquid crystal layer, and a plurality of regions that include a reflective film arranged between the first alignment film and the reflective electrode and configured by stacking a plurality of dielectric layers to reflect at least a portion of the incident light that has passed through the liquid crystal layer, and each of the plurality of regions includes the reflective film configured according to the wavelength of the incident light.

[0007] FIG. 1 is a diagram illustrating a configuration example of an optical phase modulation element according to a first embodiment of the present disclosure. FIG. 2 is a diagram illustrating a configuration example of an optical phase modulation element according to the first embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the first embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the first embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the first embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the second embodiment of the present disclosure. FIG. 8 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the second embodiment of the present disclosure. FIG. 9 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the second embodiment of the present disclosure. FIG. 10 is a diagram illustrating an example of a configuration example of an optical phase modulation element according to a third embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the third embodiment of the present disclosure. FIG. 12 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the third embodiment of the present disclosure. FIG. 13 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the third embodiment of the present disclosure. FIG. 10 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to a fourth embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example of a manufacturing method of an optical phase modulation element according to the fourth embodiment of the present disclosure. FIG. 12 is a diagram illustrating an example of a configuration of an optical phase modulation element according to a fifth embodiment of the present disclosure. FIG. 13 is a diagram illustrating an example of a configuration of an optical phase modulation element according to a sixth embodiment of the present disclosure. FIG. 14 is a diagram illustrating another example of a configuration of an optical phase modulation element according to the sixth embodiment of the present disclosure. FIG. 15 is a diagram illustrating another example of a configuration of an optical phase modulation element according to the sixth embodiment of the present disclosure. FIG. 16 is a diagram illustrating another example of a configuration of an optical phase modulation element according to the seventh embodiment of the present disclosure. FIG. 17 is a diagram illustrating an example of a configuration of an optical phase modulation element according to an eighth embodiment of the present disclosure. FIG. 18 is a diagram illustrating another example of a configuration of an optical phase modulation element according to the eighth embodiment of the present disclosure.13 is a diagram illustrating another configuration example of an optical phase modulation element according to an eighth embodiment of the present disclosure. FIG. 14 is a diagram illustrating a configuration example of a display device according to an embodiment of the present disclosure. FIG. 15 is a diagram illustrating a configuration example of a display device according to an embodiment of the present disclosure.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. Note that in the following embodiments, the same components will be assigned the same reference numerals to avoid redundant description. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Fourth embodiment 5. Fifth embodiment 6. Sixth embodiment 7. Seventh embodiment 8. Eighth embodiment 9. Configuration of display device

[0009] 1. First Embodiment [Configuration of Optical Phase Modulation Element] FIG. 1 is a diagram illustrating a configuration example of an optical phase modulation element according to a first embodiment of the present disclosure. The figure is a plan view illustrating a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 generates reflected light by modulating the phase of incident light. The optical phase modulation element 10 modulates the phase of incident light by two-dimensionally modulating the phase lead and delay within the panel surface. The optical phase modulation element 10 is divided into multiple regions. The optical phase modulation element 10 in the figure illustrates an example in which it includes regions 11, 12, and 13. Region 11 corresponds to, for example, red light. Region 12 corresponds to, for example, green light. Region 13 corresponds to, for example, blue light. The letters in the figure indicate the wavelengths of incident light corresponding to each region. "R" represents red light, "G" represents green light, and "B" represents blue light. Region 11 is an example of a "red light region" in the present disclosure. Region 12 is an example of a "green light region" in the present disclosure. Region 13 is an example of a "blue light region" in the present disclosure.

[0010] 2 is a diagram showing a configuration example of an optical phase modulation element according to the first embodiment of the present disclosure. The figure is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. As described above, the optical phase modulation element 10 includes regions 11 to 13. In the figure, open arrows represent incident light, and dotted arrows represent reflected light. Red light is incident on region 11, green light is incident on region 12, and blue light is incident on region 13.

[0011] The configuration of the optical phase modulation element 10 will be described using the region 11 as an example. The optical phase modulation element 10 includes a first substrate 110, a reflective electrode 120, a reflective film 130, a liquid crystal layer 152, alignment films 151 and 153, a counter electrode 160, and a second substrate 180.

[0012] The first substrate 110 is a substrate that supports the reflective electrode 120, the reflective film 130, and the alignment film 151. The first substrate 110 also includes a drive circuit, which will be described later. The first substrate 110 can be made of, for example, silicon.

[0013] The reflective electrode 120 is an electrode disposed for each pixel, and applies a voltage to the liquid crystal layer 152 together with the counter electrode 160. The reflective electrode 120 is connected to a drive circuit that can actively control the voltage applied to each pixel, and applies a different voltage to each pixel according to the phase modulation pattern to be displayed. This is because a different potential is applied to each pixel. The pixels are separated by an insulating film 121. The reflective electrode 120 also reflects incident light that has passed through the liquid crystal layer 152.

[0014] The reflective film 130 reflects at least a portion of the incident light that has passed through the liquid crystal layer 152. The reflective film 130 is formed by stacking a plurality of dielectric layers. These dielectric layers have different refractive indices. Among the dielectric layers, a dielectric layer with a relatively high refractive index is referred to as a high-refractive index dielectric layer. Among the dielectric layers, a dielectric layer with a relatively low refractive index is referred to as a low-refractive index dielectric layer. The reflective film 130 in FIG. 2 is formed by stacking high-refractive index dielectric layers 131 and low-refractive index dielectric layers 132. The reflective film 130 in FIG. 2 is formed by alternately stacking the high-refractive index dielectric layers 131 and the low-refractive index dielectric layers 132. The high-refractive index dielectric layers 131 and the low-refractive index dielectric layers 132 can be configured to have a film thickness that is ¼ of the wavelength λ of the incident light.

[0015] By using such a layer structure, a high reflectance can be obtained. A slight reflection occurs at the interface between the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132. As described above, the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132 are configured to have a film thickness of λ / 4, so the light reflected from each layer is in phase and constructively interacts with each other. This allows a high reflectance to be obtained. On the other hand, light that is multiple-reflected and travels parallel to the incident light is attenuated because it cancels out each other.

[0016] The high refractive index dielectric layer 131 may be made of, for example, silicon nitride (SiN). The low refractive index dielectric layer 132 may be made of, for example, silicon oxide (SiO ２ ) can be applied to the high refractive index dielectric layer 131 and the low refractive index dielectric layer 132. ２ O ３ ), hafnium oxide (HfO ２ ), niobium oxide (Nb ２ O ５ ) and tantalum oxide (Ta ２ O ５ ) can also be applied.

[0017] The alignment films 151 and 153 align liquid crystal molecules 154 (not shown) in the liquid crystal layer 152. As described above, the liquid crystal layer 152 modulates the phase of incident light. The alignment film 151 is an example of a "first alignment film" in the present disclosure. The alignment film 153 is an example of a "second alignment film" in the present disclosure.

[0018] The counter electrode 103 is an electrode that applies a voltage to the liquid crystal layer 152 together with the reflective electrode 120. The counter electrode 103 can be made of, for example, ITO (Indium Tin Oxide).

[0019] The second substrate 180 is a substrate that supports the counter electrode 103 and the alignment film 153. The second substrate 180 can be made of, for example, quartz.

[0020] The reflective film 130 is configured according to the wavelength of the incident light. As described above, the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132 constituting the reflective film 130 are configured to have a film thickness of λ / 4 to obtain high reflectivity. The reflective film 130 in region 11 includes a high-refractive-index dielectric layer 131 and a low-refractive-index dielectric layer 132 with film thicknesses corresponding to the wavelength of red light. The reflective film 130 in region 12 includes a high-refractive-index dielectric layer 131 and a low-refractive-index dielectric layer 132 with film thicknesses corresponding to the wavelength of green light. The reflective film 130 in region 13 includes a high-refractive-index dielectric layer 131 and a low-refractive-index dielectric layer 132 with film thicknesses corresponding to the wavelength of blue light. This allows the reflective film 130 to be configured optimally for the incident light in each region.

[0021] In this way, the incident light is reflected by the reflective film 130 and the reflective electrode 120, so that high reflectivity can be obtained in the regions 11 to 13. Furthermore, since most of the incident light is reflected by the reflective film 130, the incident light that reaches the reflective electrode 120 can be reduced. This makes it possible to suppress a temperature rise in the reflective electrode 120 due to the incident light.

[0022] Furthermore, since the reflective film 130 has a configuration that corresponds to the wavelength of the incident light, the wavelength dependency increases, thereby reducing the influence of color mixing.

[0023] 2 shows an example in which the number of high-refractive-index dielectric layers 131 and the number of low-refractive-index dielectric layers 132 are adjusted in the regions 11 to 13. This allows the respective reflective films 130 in the regions 11 to 13 to be configured to have approximately the same thickness.

[0024] [Method of Manufacturing Optical Phase Modulation Element] Figures 3A to 3E are diagrams showing an example of a method of manufacturing an optical phase modulation element according to the first embodiment of the present disclosure. Figures 3A to 3E are diagrams showing an example of a manufacturing process for the reflective film 130 portion of the optical phase modulation element 10. First, reflective electrodes 120 are formed on the first substrate 110 (Figure 3A). Next, insulating films 121 are disposed between the reflective electrodes 120 (Figure 3B). This can be done, for example, by disposing a material film for the insulating film 121 and grinding the surface. Note that grinding can be done, for example, by chemical mechanical polishing (CMP) and etching (etch-back).

[0025] Next, the high refractive index dielectric layer 131 and the low refractive index dielectric layer 132 of the reflective film 130 (reflective film 130a) in region 11 are formed (FIG. 3C). This can be done by vapor deposition using a mask 401 having an opening 402 in the region 11. Next, the reflective film 130 in region 12 (reflective film 130b) is formed using a mask 403 having an opening 404 in the region 12 (FIG. 3D). Next, the reflective film 130 in region 13 (reflective film 130c) is formed using a mask 405 having an opening 406 in the region 13 (FIG. 3E). Through the above steps, the reflective films 130 in regions 11 to 13 can be formed.

[0026] The configuration of the optical phase modulation element 10 is not limited to this example. For example, the optical phase modulation element 10 may have a configuration having a region corresponding to infrared light (wavelength 1550±50 nm). In the region corresponding to this infrared light, a reflective film 130 including a high-refractive-index dielectric layer 131 and a low-refractive-index dielectric layer 132 having film thicknesses according to the wavelength of the infrared light is disposed.

[0027] In this way, in the optical phase modulation element 10 according to the first embodiment of the present disclosure, the reflective films 130 having a configuration according to the wavelength of the incident light are arranged in the regions 11 to 13. This makes it possible to optimize the configuration of the reflective films 130 according to the wavelength of the incident light, thereby improving the reflectance.

[0028] (2. Second Embodiment) In the optical phase modulation element 10 of the first embodiment described above, the reflective films 130 having the same thickness are arranged in the regions 11 to 13. In contrast, the optical phase modulation element 10 of the second embodiment of the present disclosure differs from the first embodiment described above in that the reflective films 130 having different thicknesses are arranged.

[0029] [Configuration of Optical Phase Modulation Element] Fig. 4 is a diagram showing a configuration example of an optical phase modulation element according to a second embodiment of the present disclosure. Similar to Fig. 2, this figure is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 of Fig. 4 differs from the optical phase modulation element 10 of Fig. 2 in that reflective films 130 with different thicknesses are arranged in regions 11 to 13.

[0030] The reflective films 130 in the regions 11 to 13 each include the same number of high-refractive-index dielectric layers 131 and low-refractive-index dielectric layers 132. As described above, the reflective films 130 are configured according to the wavelength of incident light, and therefore the thicknesses of the reflective films 130 may differ. The optical phase modulation element 10 in Fig. 4 is configured such that the thickness of the liquid crystal layer 152 in the regions 11 to 13 is adjusted so that the thicknesses of the reflective films 130 and the liquid crystal layer 152 are uniform in the regions 11 to 13.

[0031] [Method of Manufacturing Optical Phase Modulation Element] Figures 5A-5C are diagrams illustrating an example of a method of manufacturing an optical phase modulation element according to the second embodiment of the present disclosure. Figures 5A-5C are diagrams illustrating an example of a manufacturing process for the reflective film 130 of the optical phase modulation element 10. First, the processes of Figures 3A and 3B are performed. Next, a reflective film 130a is formed using a mask 401 (Figure 5A). Next, a reflective film 130b is formed using a mask 403. At this time, the same number of high-refractive-index dielectric layers 131 and low-refractive-index dielectric layers 132 as the reflective film 130a are formed (Figure 5B). Next, a reflective film 130c is formed using a mask 405. At this time, the same number of high-refractive-index dielectric layers 131 and low-refractive-index dielectric layers 132 as the reflective film 130a are formed (Figure 5C). Through the above processes, the reflective film 130 in regions 11 to 13 can be formed.

[0032] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0033] In this way, the optical phase modulation element 10 according to the second embodiment of the present disclosure adjusts the thickness of the liquid crystal layer 152 in accordance with the thickness of the reflective film 130. This allows the thicknesses of the regions 11 to 13 to be uniform.

[0034] (3. Third Embodiment) The optical phase modulation element 10 of the second embodiment described above includes the liquid crystal layer 152 having different thicknesses in the regions 11 to 13. In contrast, the optical phase modulation element 10 of the third embodiment of the present disclosure differs from the second embodiment described above in that it includes the liquid crystal layer 152 having the same thickness in the regions 11 to 13.

[0035] [Configuration of Optical Phase Modulation Element] Fig. 6 is a diagram showing a configuration example of an optical phase modulation element according to a third embodiment of the present disclosure. Similar to Fig. 4, this figure is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in Fig. 6 differs from the optical phase modulation element 10 in Fig. 4 in that it includes a liquid crystal layer 152 having the same thickness in regions 11 to 13 and further includes a planarization film 140.

[0036] The planarization film 140 is laminated on the reflective film 130 to planarize the upper surface of the reflective film 130. This planarization film 140 can be disposed in each of the regions 11 to 13. As described above, the reflective film 130 is configured according to the wavelength of incident light, and may be configured to have different thicknesses in the regions 11 to 13. Therefore, the planarization film 140 is disposed to planarize the surface on which the alignment film 151 is formed. This allows the liquid crystal layer 152 to have a uniform thickness in the regions 11 to 13.

[0037] [Method of Manufacturing Optical Phase Modulation Element] Figures 7A to 7C are diagrams showing an example of a method of manufacturing an optical phase modulation element according to the third embodiment of the present disclosure. Figures 7A to 7C are diagrams showing an example of a manufacturing process for the reflective film 130 portion of the optical phase modulation element 10. First, the processes of Figures 5A to 5C are performed (Figure 7A). Next, a material film 407 for the planarization film 140 is disposed on the surfaces of the reflective films 130a, 130b, and 130c (Figure 7B). Next, the surface of the material film 407 is ground to form the planarization film 140 (Figure 7C). Through the above processes, the reflective film 130 in regions 11 to 13 can be formed.

[0038] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0039] As described above, in the optical phase modulation element 10 according to the third embodiment of the present disclosure, the planarization film 140 is disposed in the regions 11 to 13 to planarize the upper surface of the reflective film 130. This makes it possible to make the thickness of the liquid crystal layer 152 uniform, and to uniformly modulate the optical phase in the regions 11 to 13.

[0040] (4. Fourth Embodiment) The optical phase modulation element 10 of the first embodiment described above includes the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132 formed individually for each of the regions 11 to 13. In contrast, the optical phase modulation element 10 of the fourth embodiment of the present disclosure differs from the first embodiment described above in that the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132 are common to the regions 11 to 13.

[0041] [Configuration of Optical Phase Modulation Element] Fig. 8 is a diagram showing a configuration example of an optical phase modulation element according to a fourth embodiment of the present disclosure. Similar to Fig. 2, Fig. 8 is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in Fig. 8 differs from the optical phase modulation element 10 in Fig. 2 in that it includes a high-refractive-index dielectric layer 131 and a low-refractive-index dielectric layer 132 that are common to regions 11 to 13.

[0042] The high refractive index dielectric layer 131 and the low refractive index dielectric layer 132 in Fig. 8 are commonly disposed in the adjacent regions 11 to 13. Furthermore, the high refractive index dielectric layer 131 and the low refractive index dielectric layer 132 in Fig. 8 have film thicknesses that change continuously at least at the boundaries between the regions 11 to 13. This can simplify the manufacturing process.

[0043] [Method of Manufacturing Optical Phase Modulation Element] Figures 9A-9C are diagrams illustrating an example of a method of manufacturing an optical phase modulation element according to the fourth embodiment of the present disclosure. Figures 9A-9C are diagrams illustrating an example of a manufacturing process for the reflective film 130 of the optical phase modulation element 10. First, the processes of Figures 3A and 3B are performed. Next, deposition is performed using a mask 408 having an opening 409 to form a high-refractive-index dielectric layer 131. During this deposition, the first substrate 110 is moved laterally. The moving speed of the first substrate 110 is controlled according to the film thickness of the high-refractive-index dielectric layer 131. As a result, the high-refractive-index dielectric layer 131 is formed in regions 11 to 13 (Figure 9A). This process is repeated to form multiple high-refractive-index dielectric layers 131 and low-refractive-index dielectric layers 132 (Figure 9B). Next, the surfaces of the high-refractive-index dielectric layer 131 and the low-refractive-index dielectric layer 132 are ground and planarized (Figure 9C). Through the above processes, the reflective film 130 in regions 11 to 13 can be formed.

[0044] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0045] In this way, the optical phase modulation element 10 according to the fourth embodiment of the present disclosure has a common high-refractive-index dielectric layer 131 and the like disposed in the regions 11 to 13. This allows the manufacturing process of the optical phase modulation element 10 to be simplified.

[0046] (5. Fifth Embodiment) The optical phase modulation element 10 of the first embodiment described above includes the reflective film 130. In contrast, the optical phase modulation element 10 of the fifth embodiment of the present disclosure differs from the first embodiment described above in that it further includes an anti-reflection film.

[0047] [Configuration of Optical Phase Modulation Element] Fig. 10 is a diagram showing a configuration example of an optical phase modulation element according to a fifth embodiment of the present disclosure. Similar to Fig. 2, Fig. 10 is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in Fig. 10 differs from the optical phase modulation element 10 in Fig. 2 in that it includes antireflection films 170 and 175.

[0048] The anti-reflection film 170 is disposed on the upper surface of the counter electrode 160 to prevent reflection of incident light by the counter electrode 160. The anti-reflection film 170 is configured by laminating dielectric layers (dielectric layers 171 and 172) having different refractive indices.

[0049] The anti-reflection film 175 is disposed on the outer side of the second substrate 180 and prevents reflection of incident light by the second substrate 180. The anti-reflection film 175 can be configured by, for example, an AR (Anti-reflection) coat.

[0050] It is also possible to dispose either one of the anti-reflection films 170 and 175 .

[0051] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0052] In this way, the optical phase modulation element 10 according to the fifth embodiment of the present disclosure can prevent reflection of unwanted light by arranging the antireflection films 170 and 175 .

[0053] (6. Sixth Embodiment) In the optical phase modulation element 10 of the first embodiment described above, a common liquid crystal layer 152 is disposed in the regions 11 to 13. In contrast, the optical phase modulation element 10 of the sixth embodiment of the present disclosure differs from the first embodiment described above in that individual liquid crystal layers 152 are disposed in the regions 11 to 13.

[0054] [Configuration of Optical Phase Modulation Element] Fig. 11 is a diagram showing a configuration example of an optical phase modulation element according to a sixth embodiment of the present disclosure. Similar to Fig. 1, this figure is a plan view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in this figure differs from the optical phase modulation element 10 in Fig. 1 in that a liquid crystal layer 152 is disposed in each of the regions 11 to 13.

[0055] The optical phase modulation element 10 in Fig. 11 includes a resin layer 17 that surrounds a liquid crystal layer 152. This resin layer 17 is formed by a sealing process. The resin layer 17 also includes an inlet 18 for injecting liquid crystal. This inlet 18 is closed by a closing member 19 after the liquid crystal is injected. The resin layer 17 is an example of a "separation portion" in the present disclosure.

[0056] By disposing the resin layer 17 in which the liquid crystal layer 152 is sealed in each of the regions 11 to 13, it is possible to dispose the liquid crystal layer 152 made of different materials in the regions 11 to 13. This makes it possible to apply the liquid crystal layer 152 according to the wavelength of the incident light.

[0057] 12 is a diagram showing another configuration example of an optical phase modulation element according to the sixth embodiment of the present disclosure. Similar to FIG. 1, this figure is a plan view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in this figure differs from the optical phase modulation element 10 in FIG. 1 in that the alignment of liquid crystal molecules in a liquid crystal layer 152 is adjusted in regions 11 to 13.

[0058] In regions 11 and 13, alignment films 151 and 153 are arranged to align liquid crystal molecules 154 in the horizontal direction in Fig. 12. On the other hand, in region 12, alignment films 151 and 153 are arranged to align liquid crystal molecules 154 in the vertical direction in Fig. 12. In this way, the liquid crystal molecules of the liquid crystal layer 152 in adjacent regions 11 to 13 are aligned in orthogonal directions. This makes it possible to suppress deterioration in the quality of the reproduced image caused by reflected light irradiating adjacent regions.

[0059] 13 is a diagram showing another configuration example of an optical phase modulation element according to the sixth embodiment of the present disclosure. The figure is a schematic cross-sectional view showing a portion of the liquid crystal layer 152 of the optical phase modulation element 10. In the optical phase modulation element 10 shown in the figure, the pretilt angles of the liquid crystal molecules 154 of the liquid crystal layer 152 are different in the regions 11 to 13. This makes it possible to optimize other optical characteristics such as inter-pixel crosstalk and phase modulation for each of the regions 11 to 13.

[0060] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0061] In this way, in the optical phase modulation element 10 according to the sixth embodiment of the present disclosure, the liquid crystal layer 152 and the like are arranged in each of the regions 11 to 13. This allows the liquid crystal layer 152 to be adjusted in the regions 11 to 13.

[0062] (7. Seventh Embodiment) The optical phase modulation element 10 of the first embodiment described above includes the reflective film 130. In contrast, the optical phase modulation element 10 of the seventh embodiment of the present disclosure differs from the first embodiment described above in that it further includes a second reflective film 190.

[0063] [Configuration of Optical Phase Modulation Element] Fig. 14 is a diagram showing a configuration example of an optical phase modulation element according to a seventh embodiment of the present disclosure. Similar to Fig. 2, this figure is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in this figure differs from the optical phase modulation element 10 in Fig. 1 in that it further includes a second reflective film 190.

[0064] The second reflective film 190 reflects the light reflected by the reflective film 130. Similar to the reflective film 130, the second reflective film 190 is configured by laminating multiple dielectric layers (dielectric layers 191 and 192) with different refractive indices. By arranging the reflective film 130 and the second reflective film 190, a Fabry-Perot type liquid crystal modulator can be configured that utilizes the resonance phenomenon between the dielectric multilayer films. In this case, it is possible to optimize the modulatable wavelength range for each of the regions 11 to 13.

[0065] The configuration of the optical phase modulation element 10 other than that described above is the same as the configuration of the optical phase modulation element 10 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0066] As described above, the optical phase modulation element 10 according to the seventh embodiment of the present disclosure includes the second reflective film 190. This allows a Fabry-Perot type liquid crystal modulator to be configured. The modulatable wavelength range can be optimized for each of the regions 11 to 13.

[0067] 8. Eighth Embodiment Variations of the optical phase modulation element 10 will be described.

[0068] [Configuration of Optical Phase Modulation Element] FIG. 15 is a diagram illustrating a configuration example of an optical phase modulation element according to an eighth embodiment of the present disclosure. Similar to FIG. 2, this figure is a schematic cross-sectional view illustrating a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in this figure differs from the optical phase modulation element 10 in FIG. 2 in that the reflective film 130 in the region 11 where the incident light has a long wavelength is thin, and the reflective film 130 in the region 13 where the incident light has a short wavelength is thick. The longer the wavelength of the incident light, the thicker the liquid crystal layer 152 must be. This is to obtain the desired phase modulation amount. Therefore, by thinning the reflective film 130 in the regions 11 and 12 where the incident light has a long wavelength, the driving voltage applied to the liquid crystal layer 152 can be ensured.

[0069] [Another Configuration of Optical Phase Modulation Element] Fig. 16 is a diagram showing another configuration example of an optical phase modulation element according to the eighth embodiment of the present disclosure. Similar to Fig. 2, this figure is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 of this figure differs from the optical phase modulation element 10 of Fig. 2 in that the reflective film 130 in the region 11 is omitted. This makes it possible to improve the drive voltage applied to the liquid crystal layer 152 in the region 11.

[0070] [Another Configuration of Optical Phase Modulation Element] Fig. 17 is a diagram showing another configuration example of an optical phase modulation element according to an eighth embodiment of the present disclosure. Similar to Fig. 2, Fig. 17 is a schematic cross-sectional view showing a configuration example of an optical phase modulation element 10. The optical phase modulation element 10 in Fig. 17 differs from the optical phase modulation element 10 in Fig. 2 in that a reflective film 130 having the same configuration is disposed in regions 11 and 12. By adopting this configuration, it is possible to share the manufacturing process of the reflective film 130 in regions 11 and 12. Furthermore, it is possible to improve the flatness of the surface of the reflective film 130 in regions 11 and 12.

[0071] 18A and 18B are diagrams showing other configuration examples of an optical phase modulation element according to an eighth embodiment of the present disclosure. Similar to Fig. 1, Figs. 18A and 18B are plan views showing configuration examples of an optical phase modulation element 10. The optical phase modulation element 10 of Figs. 18A and 18B differs from the optical phase modulation element 10 of Fig. 1 in that it includes a plurality of regions 11 to 13.

[0072] Fig. 18A shows an optical phase modulation element 10 including two sets of regions 11 to 13. Fig. 19B shows an optical phase modulation element 10 including regions 11 to 13 arranged in a two-dimensional lattice pattern. By arranging two or more regions for incident light of one wavelength and separating the regions corresponding to each wavelength, it is possible to prevent degradation in the quality of the reproduced image generated by the optical phase modulation element 10.

[0073] (9. Configuration of Display Device) A display device using the optical phase modulation element 10 will be described.

[0074] 19A and 19B are diagrams illustrating an example configuration of a display device according to an embodiment of the present disclosure. Fig. 19A is a block diagram illustrating an example configuration of a display device 1. This display device 1 corresponds to a projector. The display device 1 includes an optical phase modulation element 10, a light source 20, a beam shaping optical system 30, a light intensity modulation element 40, a polarization separation element 50, a projection lens 60, and a control unit 80.

[0075] The optical phase modulation element 10 described in FIG. 1 can be applied to the optical phase modulation element 10. The light source 20 generates light to be irradiated onto the optical phase modulation element 10. The light source 20 generates red light, green light, and blue light. The beam shaping optical system 30 shapes the light from the light source 20. The light intensity modulation element 40 intensity-modulates the incident light. The polarization separation element 50 separates the light from the optical phase modulation element 10 and the light from the light intensity modulation element 40. The projection lens 60 projects the light from the polarization separation element 50 onto a screen 70. The control unit 80 generates control signals for the optical phase modulation element 10 and the light intensity modulation element 40. In FIG. 19A , solid arrows represent the trajectories of light. Furthermore, dashed arrows represent control signals.

[0076] 19B is a block diagram showing an example of the configuration of the control unit 80. The control unit 80 includes a phase pattern calculation unit 81, an optical phase modulation element driving unit 82, an intensity modulation pattern calculation unit 83, an optical intensity modulation element driving unit 84, and a holding unit 85.

[0077] The phase pattern calculation unit 81 calculates a phase pattern to be displayed by the optical phase modulation element 10 based on an image signal. The phase pattern calculation unit 81 also generates an illumination light intensity modulation pattern and outputs it to the intensity modulation pattern calculation unit 83.

[0078] The optical phase modulation element driving section 82 causes the optical phase modulation element 10 to display the phase pattern calculated by the phase pattern calculation section 81 .

[0079] The intensity modulation pattern calculation section 83 calculates an intensity modulation pattern for generating an image to be displayed by the light intensity modulation element 40 based on the image signal.

[0080] The light-intensity modulation element driving section 84 causes the light-intensity modulation element 40 to display the intensity modulation pattern calculated by the intensity modulation pattern calculation section 83 .

[0081] The light from the optical phase modulation element 10 is incident as illumination light on the light intensity modulation element 40. The light intensity modulation element 40 performs intensity modulation on the illumination light based on an intensity modulation pattern, and generates a projection image.

[0082] The holding unit 85 holds a gamma table. This gamma table contains correction values ​​for driving the regions 11 to 13 of the optical phase modulation element 10 at voltage increments that allow sufficient gradation expression. The phase pattern calculation unit 81 can generate a phase pattern based on the gamma table in the holding unit 85. Note that if a gamma table is not used, the holding unit 85 can be omitted.

[0083] The configuration of the fifth embodiment of the present disclosure can be applied to other embodiments. Specifically, the anti-reflection films 170 and 175 in Fig. 10 can be applied to the second to fourth, sixth, and seventh embodiments of the present disclosure.

[0084] The configuration of the sixth embodiment of the present disclosure can be applied to other embodiments. Specifically, the resin layer 17 of FIG. 11 can be applied to the second to fifth and seventh embodiments of the present disclosure. Furthermore, the liquid crystal layer 152 and the alignment films 151 and 153 of FIG. 12 can be applied to the second to fifth and seventh embodiments of the present disclosure. Furthermore, the liquid crystal layer 152 and the alignment films 151 and 153 of FIG. 13 can be applied to the second to fifth and seventh embodiments of the present disclosure.

[0085] The configuration of the eighth embodiment of the present disclosure can be applied to other embodiments. Specifically, regions 11 to 13 in Figures 18A and 18B can be applied to the second to seventh embodiments of the present disclosure.

[0086] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0087] The present technology may also be configured as follows: (1) An optical phase modulation element having a liquid crystal layer that adjusts the phase of incident light, a first alignment film and a second alignment film that align liquid crystal molecules in the liquid crystal layer, a counter electrode disposed adjacent to the second alignment film and that applies a drive voltage to the liquid crystal layer, a reflective electrode disposed adjacent to the first alignment film and that applies a drive voltage to the liquid crystal layer and that reflects incident light that has transmitted through the counter electrode and the liquid crystal layer, and a plurality of regions that include a reflective film disposed between the first alignment film and the reflective electrode and that is configured by stacking a plurality of dielectric layers and that reflects at least a portion of the incident light that has transmitted through the liquid crystal layer, wherein each of the plurality of regions includes the reflective film having a configuration corresponding to the wavelength of the incident light. (2) The optical phase modulation element according to (1), wherein the reflective film is configured by alternately stacking high-refractive-index dielectric layers that are the dielectric layers with a high refractive index and low-refractive-index dielectric layers that are the dielectric layers with a low refractive index. (3) The optical phase modulation element according to (2), wherein the reflective film comprises the high-refractive index dielectric layer made of silicon nitride and the low-refractive index dielectric layer made of silicon oxide. (4) The optical phase modulation element according to (2), wherein the reflective film has a thickness adjusted according to the wavelength of the incident light. (5) The optical phase modulation element according to (4), wherein the reflective film comprises the high-refractive index dielectric layer and the low-refractive index dielectric layer, each having a thickness according to the incident light. (6) The optical phase modulation element according to (4), wherein the reflective film comprises the high-refractive index dielectric layer and the low-refractive index dielectric layer, the number of layers of which corresponds to the incident light. (7) The optical phase modulation element according to (4), further comprising a planarization film stacked on the reflective film. (8) The optical phase modulation element according to any one of (1) to (7), wherein the dielectric layer is commonly disposed in the adjacent regions and has a thickness that continuously changes at least at the boundary between the adjacent regions. (9) The optical phase modulation element according to any one of (1) to (8), wherein the liquid crystal layer is configured to have a thickness adjusted in accordance with the wavelength of the incident light.(10) The optical phase modulation element according to any one of (1) to (9), which has a red light region which is the region having the reflective film configured in response to red light, a green light region which is the region having the reflective film configured in response to green light, and a blue light region which is the region having the reflective film configured in response to blue light. (11) The optical phase modulation element according to (10), which has a plurality of the red light regions, a plurality of the green light regions, and a plurality of the blue light regions. (12) The optical phase modulation element according to any one of (1) to (11), wherein the plurality of regions each have the liquid crystal layer configured in response to the wavelength of the incident light. (13) The optical phase modulation element according to (12), wherein the regions further have a separation portion separating adjacent liquid crystal layers. (14) The optical phase modulation element according to (12), wherein the plurality of regions each have the liquid crystal layer in which liquid crystal molecules are oriented in different directions in adjacent liquid crystal layers. (15) The optical phase modulation element according to (12), wherein the plurality of regions each include the liquid crystal layer having a different pretilt angle. (16) The optical phase modulation element according to any one of (1) to (15), wherein the region further includes an antireflection film that prevents reflection of the incident light. (17) The optical phase modulation element according to (16), wherein the antireflection film is disposed on a side of the counter electrode different from the side that contacts the second alignment film. (18) The optical phase modulation element according to (17), wherein the antireflection film is formed by stacking a plurality of dielectric layers. (19) The optical phase modulation element according to (16), wherein the region further includes a first substrate that supports the reflective electrode, the reflective film, and the first alignment film, and a second substrate that supports the counter electrode and the second alignment film, and wherein the antireflection film is disposed on a surface of the second substrate. (20) The optical phase modulation element according to any one of (1) to (19), further comprising a second reflective film that reflects the light reflected by the reflective film.(21) A display device comprising: an optical phase modulation element comprising: a liquid crystal layer that adjusts the phase of incident light; a first alignment film and a second alignment film that align liquid crystal molecules of the liquid crystal layer; a counter electrode arranged adjacent to the second alignment film and applying a drive voltage to the liquid crystal layer; a reflective electrode arranged adjacent to the first alignment film and applying a drive voltage to the liquid crystal layer and reflecting incident light that has passed through the counter electrode and the liquid crystal layer; and a plurality of regions having a reflective film arranged between the first alignment film and the reflective electrode and configured by stacking a plurality of dielectric layers to reflect at least a part of the incident light that has passed through the liquid crystal layer, wherein the plurality of regions each have the reflective film configured according to the wavelength of the incident light; and a light source that irradiates incident light to the optical phase modulation element.

[0088] 1 Display device 10 Optical phase modulation element 11 to 13 Region 17 Resin layer 20 Light source 85 Holding portion 103 Counter electrode 110 First substrate 120 Reflecting electrode 130, 130a, 130b, 130c Reflecting film 131 High refractive index dielectric layer 132 Low refractive index dielectric layer 140 Planarizing film 151, 153 Alignment film 152 Liquid crystal layer 160 Counter electrode 170, 175 Anti-reflection film 180 Second substrate 190 Second reflecting film

Claims

1. An optical phase modulation element having a liquid crystal layer that adjusts the phase of incident light, a first alignment film and a second alignment film that align the liquid crystal molecules of the liquid crystal layer, a counter electrode that is arranged close to the second alignment film and applies a drive voltage to the liquid crystal layer, a reflective electrode that is arranged close to the first alignment film and applies a drive voltage to the liquid crystal layer and reflects the incident light that has passed through the counter electrode and the liquid crystal layer, and a plurality of regions that are provided with a reflective film that is arranged between the first alignment film and the reflective electrode and is composed of a plurality of laminated dielectric layers and reflects at least a portion of the incident light that has passed through the liquid crystal layer, wherein each of the plurality of regions has the reflective film configured according to the wavelength of the incident light.

2. The optical phase modulation element according to claim 1, wherein the reflective film is formed by alternately stacking high-refractive index dielectric layers that are the dielectric layers with a high refractive index and low-refractive index dielectric layers that are the dielectric layers with a low refractive index.

3. The optical phase modulation element according to claim 2, wherein the reflective film comprises the high refractive index dielectric layer made of silicon nitride and the low refractive index dielectric layer made of silicon oxide.

4. The optical phase modulation element according to claim 2, wherein the reflective film has a thickness adjusted according to the wavelength of the incident light.

5. An optical phase modulation element according to claim 4, wherein the reflective film comprises the high refractive index dielectric layer and the low refractive index dielectric layer, each having a thickness corresponding to the incident light.

6. An optical phase modulation element according to claim 4, wherein the reflective film comprises the high refractive index dielectric layers and the low refractive index dielectric layers, the number of which corresponds to the number of incident light beams.

7. The optical phase modulation element according to claim 4, further comprising a planarizing film laminated on said reflective film.

8. The optical phase modulation element according to claim 1, wherein the dielectric layer is disposed in common in the adjacent regions, and the thickness of the dielectric layer varies continuously at least at the boundary between the adjacent regions.

9. The optical phase modulation element according to claim 1, wherein the liquid crystal layer is configured to have a thickness adjusted according to the wavelength of the incident light.

10. An optical phase modulation element as described in claim 1, having a red light region which is the region having the reflective film configured in response to red light, a green light region which is the region having the reflective film configured in response to green light, and a blue light region which is the region having the reflective film configured in response to blue light.

11. The optical phase modulation element according to claim 10, comprising a plurality of said red light regions, a plurality of said green light regions, and a plurality of said blue light regions.

12. The optical phase modulation element according to claim 1, wherein each of the plurality of regions comprises the liquid crystal layer having a configuration corresponding to the wavelength of the incident light.

13. The optical phase modulation element according to claim 12, wherein the regions further have separation sections that separate adjacent portions of the liquid crystal layer.

14. The optical phase modulation element according to claim 12, wherein the plurality of regions each comprise a liquid crystal layer in which the liquid crystal molecules in adjacent regions are oriented in different directions.

15. The optical phase modulation element according to claim 12, wherein the plurality of regions each include the liquid crystal layer having a different pretilt angle.

16. The optical phase modulation element according to claim 1, wherein the region further comprises an anti-reflection film for preventing reflection of the incident light.

17. The optical phase modulation element according to claim 16, wherein the antireflection film is disposed on a side of the counter electrode different from the side in contact with the second alignment film.

18. The optical phase modulation element according to claim 17, wherein the antireflection film is formed by laminating a plurality of dielectric layers.

19. An optical phase modulation element as described in claim 16, wherein the region further comprises a first substrate supporting the reflective electrode, the reflective film, and the first alignment film, and a second substrate supporting the counter electrode and the second alignment film, and the anti-reflection film is disposed on the surface of the second substrate.

20. A display device comprising: an optical phase modulation element comprising: a liquid crystal layer that adjusts the phase of incident light; a first alignment film and a second alignment film that align liquid crystal molecules in the liquid crystal layer; a counter electrode arranged adjacent to the second alignment film and applying a drive voltage to the liquid crystal layer; a reflective electrode arranged adjacent to the first alignment film and applying a drive voltage to the liquid crystal layer and reflecting incident light that has passed through the counter electrode and the liquid crystal layer; and a plurality of regions having a reflective film arranged between the first alignment film and the reflective electrode and composed of a plurality of laminated dielectric layers that reflects at least a portion of the incident light that has passed through the liquid crystal layer, wherein each of the plurality of regions has the reflective film configured according to the wavelength of the incident light; and a light source that irradiates incident light to the optical phase modulation element.

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