Liquid crystal display element and display device

Abstract

A liquid crystal display element according to the present disclosure comprises: a first substrate; a second substrate disposed facing the first substrate so as to interpose a liquid crystal layer including a plurality of liquid crystal molecules between the second substrate and the first substrate; a first electrode unit formed on an effective pixel region and a peripheral region of the effective pixel region on the first substrate; a second electrode unit having a pixel electrode unit formed on an effective pixel region on the second substrate, and a peripheral driving electrode formed on a peripheral region on the second substrate; a first alignment film formed on the effective pixel regions on each of the first substrate and the second substrate, whose alignment direction is a first azimuth angle; and a second alignment film formed on the peripheral regions on each of the first substrate and the second substrate, whose alignment direction is a second azimuth angle differing by 45° relative to the first azimuth angle.

Description

Liquid crystal display element and display device

[0001] The present disclosure relates to a liquid crystal display element and a display device.

[0002] In liquid crystal display elements, technologies have been developed to suppress the effects of ionic impurities that have flowed into the liquid crystal layer on the display characteristics (see, for example, Patent Documents 1 and 2). Patent Document 1 proposes a technology in which different driving voltages are applied between multiple electrodes provided in the peripheral region of the effective pixel region to generate a horizontal electric field, thereby moving impurity ions outside the effective pixel region.

[0003] JP 2008-58497 A JP 2012-123144 A

[0004] In the above-mentioned technology, it is conceivable that unwanted light may be generated in the peripheral region. In such a case, for example, a mechanical light-shielding portion may be provided to suppress the unwanted light, but in that case, vignetting of the light emitted from the effective pixel region may occur, which may result in degradation of image quality.

[0005] It is desirable to provide a liquid crystal display element and a display device that can suppress deterioration of image quality and generation of unnecessary light.

[0006] A liquid crystal display element according to one embodiment of the present disclosure comprises: a second substrate arranged opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a second electrode portion having a first electrode portion formed in an effective pixel region of the first substrate and a peripheral region of the effective pixel region of the first substrate, a pixel electrode portion formed in the effective pixel region of the second substrate, and a peripheral driving electrode portion formed in the peripheral region of the second substrate; a first alignment film formed in the effective pixel region of each of the first substrate and the second substrate, the alignment direction of which is at a first azimuth angle; and a second alignment film formed in the peripheral region of each of the first substrate and the second substrate, the alignment direction of which is at a second azimuth angle that is 45° different from the first azimuth angle.

[0007] A display device according to one embodiment of the present disclosure includes a liquid crystal display element and a projection optical system that projects an image generated by the liquid crystal display element, and the liquid crystal display element includes: a first substrate; a second substrate arranged opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a second electrode portion having a first electrode portion formed in an effective pixel region of the first substrate and a peripheral region of the effective pixel region of the first substrate, a pixel electrode portion formed in the effective pixel region of the second substrate, and a peripheral driving electrode portion formed in the peripheral region of the second substrate; a first alignment film formed in the effective pixel region of each of the first substrate and the second substrate, and having an alignment direction at a first azimuth angle; and a second alignment film formed in the peripheral region of each of the first substrate and the second substrate, and having an alignment direction at a second azimuth angle that is 45° different from the first azimuth angle.

[0008] In a liquid crystal display element or display device according to one embodiment of the present disclosure, a peripheral drive electrode portion is formed in the peripheral region of the effective pixel region, and a second alignment film is formed in the peripheral region, the second alignment film having an azimuth angle that differs by 45° from that of the first alignment film formed in the effective pixel region.

[0009] 1 is a cross-sectional view showing a first configuration example of a liquid crystal display element according to a comparative example; FIG. 2 is a cross-sectional view showing a first configuration example of a liquid crystal display element according to a first embodiment of the present disclosure; FIG. 3 is a plan view showing a first configuration example of a liquid crystal display element according to the first embodiment; FIG. 4 is an explanatory diagram showing an overview of a luminance modulation type liquid crystal element; FIG. 5 is an explanatory diagram showing an overview of a phase modulation type liquid crystal element; FIG. 6 is a cross-sectional view showing a second configuration example of a liquid crystal display element according to a comparative example; FIG. 7 is a cross-sectional view showing a second configuration example of a liquid crystal display element according to the first embodiment; FIG. 8 is a plan view showing a first modified example of a liquid crystal display element according to the first embodiment; FIG. 9 is a cross-sectional view showing a second modified example of a liquid crystal display element according to the first embodiment;

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order: 1. First embodiment (liquid crystal element with luminance modulation type effective pixel area) 1.1 Configuration and operation of liquid crystal display element (FIGS. 1 to 7) 1.2 Modifications (FIGS. 8 and 9) 1.3 Application example to display device (FIGS. 10 and 11) 1.4 Effects 2. Second embodiment (liquid crystal element with phase modulation type effective pixel area) (FIGS. 12 and 13) 3. Other embodiments

[0011] 1. First embodiment (liquid crystal element having a luminance modulation type effective pixel area) [1.1 Configuration and operation of liquid crystal display element] (Liquid crystal display element according to comparative example) FIG. 1 shows an example of a cross-sectional configuration of a liquid crystal display element 101 according to a first configuration example of the comparative example.

[0012] As a first configuration example of a comparative example, a configuration example of a reflective liquid crystal display element is shown. This liquid crystal display element 101 is configured as a brightness modulation type liquid crystal element as a whole. This liquid crystal display element 101 includes a counter substrate 10 as a first substrate and a pixel substrate 20 as a second substrate. The pixel substrate 20 is disposed opposite the counter substrate 10 so as to sandwich a liquid crystal layer 30 containing a plurality of liquid crystal molecules 31 between the pixel substrate 20 and the counter substrate 10. The peripheries of the counter substrate 10 and the pixel substrate 20 are joined to each other via a sealant 13.

[0013] The counter substrate 10 is made of an optically transparent material such as glass or transparent resin. A counter electrode section 11 serving as a first electrode section is formed over the entire surface of the effective pixel region 130 of the counter substrate 10 and the peripheral region 120 of the effective pixel region 130 of the counter substrate 10. The counter electrode section 11 is a common electrode formed of a transparent conductive film such as an ITO (indium tin oxide) film. A single alignment film 12 is formed over the entire surface of the effective pixel region 130 and the peripheral region 120 of the counter substrate 10, covering the counter electrode section 11. The alignment direction of the alignment film 12 is, for example, inclined at 45° with respect to the polarization direction of incident light. The alignment film 12 is, for example, made of a vapor-deposited film of an inorganic material or an organic film obtained by rubbing an organic material such as polyimide.

[0014] The effective pixel area 130 is, for example, a rectangular area when the liquid crystal display element 101 is viewed in a plan view. The peripheral area 120 is an area that surrounds the rectangular effective pixel area 130 when the liquid crystal display element 101 is viewed in a plan view.

[0015] The pixel substrate 20 is formed, for example, by a TFT (Thin Film Transistor) substrate. A pixel electrode section 21A is formed in an effective pixel region 130 of the pixel substrate 20. The pixel electrode section 21A includes, for example, a plurality of pixel electrodes arranged in a matrix. A peripheral driving electrode section 21B is formed in a peripheral region 120 of the effective pixel region 130 of the pixel substrate 20. A single alignment film 22 is formed in the effective pixel region 130 and the peripheral region 120 of the pixel substrate 20 so as to cover the pixel electrode section 21A and the peripheral driving electrode section 21B over the entire surface. The alignment direction of the alignment film 22 is, for example, inclined at 45° with respect to the polarization direction of incident light. The alignment film 22 is formed, for example, by a vapor-deposited film made of an inorganic material or an organic film obtained by rubbing an organic material such as polyimide.

[0016] The peripheral driving electrode unit 21B includes one or more electrodes. The peripheral driving electrode unit 21B generates a horizontal electric field by applying a periodically alternating rectangular driving voltage between adjacent electrodes among the plurality of electrodes, for example, and is capable of moving impurity ions to the peripheral region 120. In a method in which a rectangular driving voltage is also applied to the pixel electrode unit 21A, the frequency of the driving voltage applied to the peripheral driving electrode unit 21B may be set higher than the frequency of the driving voltage applied to the pixel electrode unit 21A. Furthermore, the magnitude (amplitude) of the driving voltage applied to the peripheral driving electrode unit 21B may be set higher than the magnitude (amplitude) of the driving voltage applied to the pixel electrode unit 21A.

[0017] In the liquid crystal display element 101, in the effective pixel region 130, incident light that has entered the counter substrate 10 is modulated by the liquid crystal layer 30, reflected by the pixel electrode portion 21A, and emitted from the counter substrate 10 side. In the liquid crystal display element 101, reflected light whose polarization direction (reflection polarization axis) is perpendicular to the polarization direction of the incident light (incident polarization axis) is emitted as output light L1 via the analyzer 41. The analyzer 41 is, for example, a polarizing plate having a predetermined transmission polarization axis. The transmission polarization axis of the analyzer 41 is configured to be in the same direction as the reflection polarization axis of the reflected light that is emitted from the liquid crystal display element 101.

[0018] In the liquid crystal display element 101, the alignment film 12 and the alignment film 22 are formed in the effective pixel region 130 and the peripheral region 120, with the same alignment direction. Therefore, even in the peripheral region 120, incident light entering the counter substrate 10 is modulated by the liquid crystal layer 30, reflected by the peripheral drive electrode section 21B, and emitted from the counter substrate 10. That is, in the liquid crystal display element 101, reflected light in the peripheral region 120, whose polarization direction (reflection polarization axis) is perpendicular to the polarization direction (incident polarization axis) of the incident light, is emitted as output light L2 via the analyzer 41. This output light L2 in the peripheral region 120 becomes unwanted light. In this case, it is conceivable to suppress the unwanted light by providing a light-shielding mask 51 as a mechanical light-shielding section. However, providing the light-shielding mask 51 may cause vignetting of the output light L1 from the effective pixel region 130, resulting in degradation of image quality. Therefore, in the configuration of the liquid crystal display element 101, it is difficult to suppress vignetting of the light L1 emitted from the effective pixel area 130 while suppressing image quality degradation due to impurity ions using the peripheral drive electrode portion 21B.

[0019] (Liquid crystal display element according to the first embodiment) Fig. 2 shows an example of a cross-sectional configuration of a liquid crystal display element 1 according to a first configuration example of the first embodiment of the present disclosure. Fig. 3 shows an example of a planar configuration of a liquid crystal display element 1 according to the first configuration example of the first embodiment. Below, we will explain the parts that are different from the liquid crystal display element 101 according to the comparative example shown in Fig. 1.

[0020] As a first configuration example of the first embodiment, a configuration example of a reflective liquid crystal display element is shown. In this liquid crystal display element 1, first alignment films (alignment films 12A and 22A) are formed in the effective pixel region 130 of each of the counter substrate 10 and the pixel substrate 20. The alignment film 12A is formed on the counter substrate 10 so as to cover the counter electrode portion 11 in the effective pixel region 130. The alignment film 22A is formed on the pixel substrate 20 so as to cover the pixel electrode portion 21A in the effective pixel region 130. The alignment directions (first azimuth angle) of the alignment films 12A and 22A are inclined at 45° with respect to the polarization direction of incident light, for example. The alignment film 12 is formed, for example, by a vapor deposition film made of an inorganic material or an organic film made by rubbing an organic material such as polyimide.

[0021] Furthermore, in this liquid crystal display element 1, second alignment films (alignment films 12B and 22B) are formed in the peripheral region 120 of each of the counter substrate 10 and the pixel substrate 20. The alignment film 12B is formed on the counter substrate 10 so as to cover the counter electrode portion 11 in the peripheral region 120. The alignment film 22B is formed on the pixel substrate 20 so as to cover the peripheral drive electrode portion 21B in the peripheral region 120. The alignment directions (second azimuth angles) of the alignment films 12B and 22B are configured to be 45° different from the alignment directions (first azimuth angles) of the alignment films 12A and 22A. The alignment directions (second azimuth angles) of the alignment films 12B and 22B are, for example, parallel to the polarization direction of incident light. Alternatively, the alignment directions (second azimuth angles) of the alignment films 12B and 22B may be configured to be perpendicular to the polarization direction of incident light. The alignment film 12B and the alignment film 22B are made of, for example, a vapor-deposited film made of an inorganic material, or an organic film made of an organic material such as polyimide that has been subjected to a rubbing treatment.

[0022] This liquid crystal display element 1 is configured to operate as a luminance modulation type liquid crystal element in the effective pixel region 130, and as a phase modulation type liquid crystal element (SLM (Spatial Light Modulator)) in the peripheral region 120. Fig. 4 shows an overview of a luminance modulation type liquid crystal element. Fig. 5 shows an overview of a phase modulation type liquid crystal element. For the purpose of explanation, Figs. 4 and 5 show an example of the configuration of a transmissive type liquid crystal element.

[0023] In a brightness modulation liquid crystal element, a polarizer 42, e.g., a polarizing plate, is generally arranged in the direction of light incidence, and an analyzer 41, e.g., a polarizing plate, is arranged in the direction of light emission. The polarizer 42 has a predetermined transmission polarization axis and emits polarized light polarized in a predetermined polarization direction. In a brightness modulation liquid crystal element, the orientation direction of the liquid crystal molecules 31 in the liquid crystal layer 30 (the long axis of the liquid crystal molecules 31) is tilted at 45° with respect to the transmission polarization axis of the polarizer 42 when viewed from the front, as shown in FIG. 4 . The inclination of the liquid crystal molecules 31 in the cross section changes depending on the voltage applied to the liquid crystal layer 30. As a result, the polarization state of modulated light emitted from the brightness modulation liquid crystal element changes depending on the applied voltage. The amount of light finally emitted from the analyzer 41 changes depending on the polarization state of the modulated light.

[0024] For example, when no voltage is applied to the liquid crystal layer 30, the liquid crystal molecules 31 are aligned almost perpendicular to the substrate surface of the liquid crystal element. Linearly polarized light incident on the liquid crystal layer 30 passes through the liquid crystal layer 30 without being affected by the liquid crystal molecules 31. When the polarizer 42 and the analyzer 41 are arranged in a crossed Nicol configuration, the final light output state is a black display.

[0025] Furthermore, for example, when a predetermined voltage is applied to the liquid crystal layer 30, the liquid crystal molecules 31 are oriented substantially parallel to the substrate surface of the liquid crystal element. In this case, linearly polarized light incident on the liquid crystal layer 30 becomes linearly polarized light rotated by 90° within the liquid crystal layer 30. Under the condition that the polarizer 42 and the analyzer 41 are arranged in a crossed Nicol configuration, the modulated light passes through the analyzer 41, and the final emitted light displays white.

[0026] In a phase modulation type liquid crystal element, a polarizer 42, for example, made of a polarizing plate, is generally arranged in the incident direction of light, and an analyzer 42 is not arranged in the outgoing direction of light. In a phase modulation type liquid crystal element, the orientation direction of the liquid crystal molecules 31 in the liquid crystal layer 30 (the long axes of the liquid crystal molecules 31) is, for example, parallel to the transmission polarization axis of the polarizer 42 when viewed from the front, as shown in FIG. 5 . The inclination of the liquid crystal molecules 31 in the cross section changes depending on the voltage applied to the liquid crystal layer 30. As a result, the phase state of the modulated light emitted from the phase modulation type liquid crystal element changes depending on the applied voltage.

[0027] In a phase modulation type liquid crystal element, only the phase of light changes depending on the tilt of the liquid crystal molecules 31, and the polarization state does not change, so the brightness does not change.

[0028] For example, when no voltage is applied to the liquid crystal layer 30, the liquid crystal molecules 31 are aligned almost perpendicular to the substrate surface of the liquid crystal element. The polarization direction of linearly polarized light incident on the liquid crystal layer 30 is consistent with the director of the liquid crystal molecules 31, so the polarization direction does not change. If the refractive index of the liquid crystal layer 30 in this state is n1 and the thickness of the liquid crystal layer 30 is d, then the phase delay of the light emitted from the phase modulation type liquid crystal element is n1d.

[0029] Furthermore, for example, when a predetermined voltage is applied to the liquid crystal layer 30, the liquid crystal molecules 31 are oriented approximately parallel to the substrate surface of the liquid crystal element. In this case, the polarization direction of linearly polarized light incident on the liquid crystal layer 30 coincides with the director of the liquid crystal molecules 31, so the polarization direction does not change. When the liquid crystal molecules 31 are parallel to the substrate surface of the liquid crystal element, the refractive index anisotropy of the liquid crystal molecules 31 is maximized. The refractive index of the liquid crystal layer 30 is calculated by subtracting the refractive index of the ordinary ray no from the refractive index of the extraordinary ray n e. If the refractive index of the liquid crystal layer 30 in this state is n2 and the thickness of the liquid crystal layer 30 is d, the phase delay amount of the light emitted from the phase modulation type liquid crystal element is n2d.

[0030] Returning to FIGS. 2 and 3, the liquid crystal display element 1 will be described again.

[0031] As described above, the liquid crystal display element 1 has a first alignment film and a second alignment film whose alignment directions are 45° different from each other in the effective pixel region 130 and the peripheral region 120. This allows the liquid crystal display element 1 to function as a brightness modulation liquid crystal element in the effective pixel region 130 and as a phase modulation liquid crystal element in the peripheral region 120. Therefore, even if incident light entering the counter substrate 10 is modulated by the liquid crystal layer 30 in the peripheral region 120, the polarization direction remains unchanged, and only the phase changes. In the peripheral region 120, even if reflected light whose polarization direction (reflection polarization axis) is parallel to the polarization direction (incident polarization axis) of the incident light reaches the analyzer 41 as output light L2, the reflected light is blocked by the analyzer 41. This means that unwanted light can be suppressed without the need for a light-shielding mask 51 for suppressing unwanted light, as in the liquid crystal display element 101 of the comparative example shown in FIG. 1 . This allows the liquid crystal display element 1 to suppress image quality degradation due to impurity ions using the peripheral drive electrode unit 21B while suppressing vignetting of output light L1 from the effective pixel region 130.

[0032] Although the above description has been given taking the configuration of a reflective liquid crystal display element as an example, the present technology can also be applied to a transmissive liquid crystal display element.

[0033] FIG. 6 shows an example of a cross-sectional configuration of a liquid crystal display element 102 according to a second configuration example of the comparative example.

[0034] Here, we will explain the differences from the liquid crystal display element 101 according to the comparative example shown in Fig. 1. Also, here, we will explain an example in which a polarizer 42 made of a polarizing plate is arranged on the pixel substrate 20 side, and an analyzer 41 is arranged on the counter substrate 10 side. The transmission polarization axis of the polarizer 42 and the transmission polarization axis of the analyzer 41 are orthogonal to each other, and the polarizer 42 and the analyzer 41 are arranged in a crossed Nicol configuration.

[0035] In the liquid crystal display element 102, in the effective pixel region 130, incident light that has entered the pixel substrate 20 is modulated by the liquid crystal layer 30 and emitted from the counter substrate 10. In the liquid crystal display element 102, transmitted light whose polarization direction is orthogonal to the polarization direction of the incident light (incident polarization axis) is emitted as output light L11 via the analyzer 41.

[0036] In the liquid crystal display element 102, alignment films 12 and 22 with the same alignment direction are formed in the effective pixel region 130 and the peripheral region 120. Therefore, even in the peripheral region 120, incident light entering the pixel substrate 20 is modulated by the liquid crystal layer 30 and emitted from the counter substrate 10. That is, in the liquid crystal display element 102, even in the peripheral region 120, transmitted light whose polarization direction is perpendicular to the polarization direction (incident polarization axis) of the incident light is emitted as output light L12 via the analyzer 41. This output light L12 in the peripheral region 120 becomes unwanted light. In this case, it is possible to suppress the unwanted light by providing, for example, a light-shielding mask 51 as a mechanical light-shielding unit. However, providing the light-shielding mask 51 may cause vignetting of the output light L11 from the effective pixel region 130, resulting in degradation of image quality. For this reason, in the configuration of the liquid crystal display element 102, it is difficult to suppress vignetting of the light L11 emitted from the effective pixel area 130 while suppressing image quality degradation due to impurity ions using the peripheral drive electrode portion 21B.

[0037] Fig. 7 shows an example of a cross-sectional configuration of a liquid crystal display element 2 according to a second configuration example of the first embodiment. Below, differences from the liquid crystal display element 102 according to the comparative example shown in Fig. 6 and the liquid crystal display element 1 shown in Fig. 2 will be described. Here, an example will be described in which a polarizer 42 made of a polarizing plate is disposed on the pixel substrate 20 side, and an analyzer 41 is disposed on the counter substrate 10 side. The transmission polarization axes of the polarizer 42 and the analyzer 41 are orthogonal to each other, and the polarizer 42 and the analyzer 41 are disposed in a crossed Nicol configuration.

[0038] The liquid crystal display element 2 has a first alignment film (alignment film 12A, alignment film 22A) and a second alignment film (alignment film 12B, alignment film 22B) whose alignment directions differ by 45° between the effective pixel region 130 and the peripheral region 120. This allows the liquid crystal display element 2 to function as a brightness modulation type liquid crystal element in the effective pixel region 130 and as a phase modulation type liquid crystal element in the peripheral region 120. Therefore, even if incident light entering the pixel substrate 20 is modulated by the liquid crystal layer 30 in the peripheral region 120, the polarization direction remains unchanged, and only the phase changes. In the peripheral region 120, even if transmitted light whose polarization direction is parallel to the polarization direction (incident polarization axis) of the incident light reaches the analyzer 41 as output light L12, it is blocked by the analyzer 41. In other words, it is possible to suppress unwanted light without providing a light-shielding mask 51 for suppressing unwanted light, as in the liquid crystal display element 102 according to the comparative example shown in FIG. 6 . As a result, in the liquid crystal display element 2, the peripheral drive electrode portion 21B can suppress deterioration of image quality due to impurity ions, while suppressing vignetting of the light L11 emitted from the effective pixel region 130.

[0039] [1.2 Modifications] (Modification 1) FIG. 8 shows a configuration example of Modification 1 of the liquid crystal display element 1 according to the first embodiment.

[0040] 3, the liquid crystal molecules 31 in the peripheral region 120 are configured to be parallel to the horizontal direction when the liquid crystal display element 1 is viewed in a plane, but as shown in Fig. 8, the liquid crystal molecules 31 in the peripheral region 120 may be configured to be parallel to the vertical direction when viewed in a plane. In this case, too, the alignment direction (second azimuth angle) of the second alignment film (alignment film 12B, alignment film 22B) is configured to be a direction that differs by 45° from the alignment direction (first azimuth angle) of the first alignment film (alignment film 12A, alignment film 22A).

[0041] (Modification 2) FIG. 9 shows a configuration example of modification 2 of the liquid crystal display element 1 according to the first embodiment.

[0042] In the configuration of the liquid crystal display element 1 shown in FIG. 2 , the peripheral drive electrode unit 21B may be configured to include multiple electrodes. In this case, a rectangular drive voltage that periodically alternates between adjacent electrodes among the multiple electrodes generates a transverse electric field, making it possible to migrate impurity ions to the peripheral region 120. In a system in which a rectangular drive voltage is also applied to the pixel electrode unit 21A, the frequency of the drive voltage applied to the peripheral drive electrode unit 21B may be set higher than the frequency of the drive voltage applied to the pixel electrode unit 21A. Furthermore, the magnitude (amplitude) of the drive voltage applied to the peripheral drive electrode unit 21B may be set higher than the magnitude (amplitude) of the drive voltage applied to the pixel electrode unit 21A.

[0043] [1.3 Example of application to a display device] Fig. 10 shows a first example of the configuration of a display device according to the first embodiment. Fig. 10 shows an example of the configuration of a projection display device (projector) using a reflective liquid crystal display element as the display device. As the reflective liquid crystal display element, for example, the liquid crystal display element 1 shown in Fig. 2 can be used.

[0044] The display device shown in FIG. 10 includes a light source 60, an illumination optical system 61, a PBS (polarizing beam splitter) 62, a liquid crystal display element 1, and a projection optical system .

[0045] The light source 60 is, for example, a laser light source. The illumination optical system 61 includes a fly's eye lens, a collimating lens, etc. The illumination optical system 61 emits light from the light source 60 as illumination light toward the PBS 62. The PBS 62 reflects, for example, S-polarized light and transmits P-polarized light. The PBS 62 acts as a polarizer for the illumination light from the illumination optical system 61. The PBS 62 emits the S-polarized light toward the liquid crystal display element 1. The liquid crystal display element 1 modulates the S-polarized light and emits P-polarized light toward the PBS 62. The PBS 62 acts as an analyzer for the light emitted from the liquid crystal display element 1. The modulated light from the liquid crystal display element 1 is incident on the projection optical system 70 via the PBS 62. The projection optical system 70 is, for example, a projection lens. The projection optical system 70 projects the modulated light from the liquid crystal display element 1 onto a screen 71 as an image.

[0046] FIG. 11 shows a second configuration example of the display device according to the first embodiment.

[0047] 11 shows an example of the configuration of a projection display device (projector) using a transmissive liquid crystal display element as a display device. As the transmissive liquid crystal display element, for example, the liquid crystal display element 2 shown in FIG. 7 can be used.

[0048] 11 includes a light source 60, an illumination optical system 61, a polarizer 42, a liquid crystal display element 2, an analyzer 41, and a projection optical system 70. The transmission polarization axis of the polarizer 42 and the transmission polarization axis of the analyzer 41 are orthogonal to each other, and the polarizer 42 and the analyzer 41 are arranged in a crossed Nicol state.

[0049] The light source 60 is, for example, a laser light source. The illumination optical system 61 includes a fly's eye lens, a collimator lens, etc. The illumination optical system 61 emits light from the light source 60 as illumination light toward the liquid crystal display element 2 via the analyzer 41. The liquid crystal display element 2 modulates the incident light and emits it toward the analyzer 41. The modulated light from the liquid crystal display element 2 is incident on the projection optical system 70 via the analyzer 41. The projection optical system 70 is, for example, a projection lens. The projection optical system 70 projects the modulated light from the liquid crystal display element 2 as an image onto a screen 71.

[0050] [1.4 Effects] As described above, in the liquid crystal display element and display device according to the first embodiment, the peripheral drive electrode section 21B is formed in the peripheral region 120 of the effective pixel region 130, and the second alignment film (alignment film 12B, alignment film 22B) whose azimuth angle differs by 45° from that of the first alignment film (alignment film 12A, alignment film 22A) formed in the effective pixel region 130 is formed in the peripheral region 120. This makes it possible to suppress image quality degradation and generation of unnecessary light.

[0051] The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved. The same applies to the effects of other embodiments described below.

[0052] 2. Second embodiment (liquid crystal element having a phase modulation type effective pixel area) Next, a liquid crystal display element and a display device according to a second embodiment of the present disclosure will be described. Note that, hereinafter, parts that are substantially the same as the components of the liquid crystal display element and the display device according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0053] FIG. 12 shows an example of the configuration of a liquid crystal display element 102A and a display device according to a comparative example.

[0054] The display device shown in FIG. 12 includes a light source 80, an illumination optical system 81, a liquid crystal display element 102A, a light-shielding mask 82, and a projection optical system 90.

[0055] The liquid crystal display element 102A according to the comparative example has an effective pixel area 130A and a peripheral area 120A, and the entire area including the effective pixel area 130A and the peripheral area 120A is configured as a phase modulation type liquid crystal element. The effective pixel area 130A is provided with a counter electrode section 11 and a pixel electrode section 21A, similar to the liquid crystal display element according to the comparative example of the first embodiment. The peripheral area 120A is provided with a counter electrode section 11 and a peripheral drive electrode section 21B, similar to the liquid crystal display element according to the comparative example of the first embodiment.

[0056] The light source 80 is, for example, a laser light source. The illumination optical system 81 includes a fly's eye lens, a collimator lens, etc. The illumination optical system 81 emits light from the light source 80 as illumination light toward the liquid crystal display element 102A. The liquid crystal display element 102A phase-modulates the incident light and emits it toward the projection optical system 90. The projection optical system 90 is, for example, a projection lens. The projection optical system 90 projects the modulated light from the liquid crystal display element 102A onto the screen 71 as an image.

[0057] Here, in the liquid crystal display element 102A, similar to the liquid crystal display element according to the comparative example of the first embodiment, alignment films with the same alignment direction are formed in the effective pixel region 130A and the peripheral region 120A. Therefore, light is phase-modulated and emitted even in the peripheral region 120A. This emitted light in the peripheral region 120A becomes unwanted light. In this case, it is conceivable to suppress the unwanted light by providing a light-shielding mask 82 as a mechanical light-shielding unit. However, providing the light-shielding mask 82 may cause vignetting of the light emitted from the effective pixel region 130A, resulting in image quality degradation. Therefore, with the configuration of the liquid crystal display element 102A, it is difficult to suppress vignetting of the light emitted from the effective pixel region 130A while suppressing image quality degradation due to impurity ions using the peripheral drive electrode unit 21B.

[0058] 13 shows an example of the configuration of a liquid crystal display element 2A and a display device according to the second embodiment. The following describes the differences from the liquid crystal display element 102A and the display device according to the comparative example shown in FIG.

[0059] The display device shown in FIG. 13 includes a light source 80, an illumination optical system 81, a liquid crystal display element 2A, an analyzer 83, and a projection optical system 90.

[0060] The liquid crystal display element 2A has a first alignment film and a second alignment film formed in the effective pixel region 130A and the peripheral region 120A, whose alignment directions differ by 45° from each other. This allows the liquid crystal display element 2A to function as a phase modulation type liquid crystal element in the effective pixel region 130A and as a brightness modulation type liquid crystal element in the peripheral region 120A. In the liquid crystal display element 2A, the alignment direction (first azimuth angle) of the first alignment film formed in the effective pixel region 130A is parallel (0°) to the polarization direction of the incident light. The alignment direction (second azimuth angle) of the second alignment film formed in the peripheral region 120A is tilted by 45°. Therefore, in the liquid crystal display element 2A, the polarization direction of the incident light is rotated by 90° in the peripheral region 120A. Even if the light emitted from the peripheral region 120A reaches the analyzer 83, it is blocked by the analyzer 83. The transmission polarization axis of the analyzer 83 is in the same direction as the light emitted from the effective pixel region 130A of the liquid crystal display element 2A, and the light emitted from the effective pixel region 130A passes through the analyzer 83. That is, the liquid crystal display element 2A can suppress unwanted light without providing the light-shielding mask 82 for suppressing unwanted light as in the liquid crystal display element 102A according to the comparative example shown in Fig. 12. As a result, the liquid crystal display element 2A can suppress vignetting of the light L11 emitted from the effective pixel region 130A while suppressing image quality degradation due to impurity ions using the peripheral drive electrode portion 21B.

[0061] Other configurations, operations, and effects may be substantially the same as those of the liquid crystal display element and display device according to the first embodiment.

[0062] 3. Other Embodiments The technology according to the present disclosure is not limited to the above-described embodiments, and various modifications are possible.

[0063] For example, the present technology can be configured as follows: According to the present technology configured as follows, a peripheral drive electrode is formed in a peripheral region of an effective pixel region, and a second alignment film is formed in the peripheral region, the second alignment film having an azimuth angle that differs by 45° from that of the first alignment film formed in the effective pixel region. This makes it possible to suppress image quality degradation and generation of unnecessary light.

[0064] (1) A liquid crystal display element comprising: a first substrate; a second substrate disposed opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a first electrode portion formed in an effective pixel region of the first substrate and in a peripheral region of the effective pixel region of the first substrate; a second electrode portion having a pixel electrode portion formed in the effective pixel region of the second substrate and a peripheral drive electrode formed in the peripheral region of the second substrate; a first alignment film formed in the effective pixel region of each of the first substrate and the second substrate, the alignment direction of which is at a first azimuth angle; and a second alignment film formed in the peripheral region of each of the first substrate and the second substrate, the alignment direction of which is at a second azimuth angle that is 45° different from the first azimuth angle. (2) The liquid crystal display element according to (1), wherein the first azimuth angle is a direction tilted by 45° with respect to the polarization direction of incident light, and the second azimuth angle is parallel or perpendicular to the polarization direction of the incident light. (3) The liquid crystal display element according to (2), wherein the liquid crystal display element is configured to operate as a brightness modulation liquid crystal element in the effective pixel region and as a phase modulation liquid crystal element in the peripheral region. (4) The liquid crystal display element according to (1), wherein the first azimuth angle is parallel to the polarization direction of incident light, and the second azimuth angle is a direction tilted by 45° with respect to the polarization direction of the incident light. (5) The liquid crystal display element according to (4), wherein the liquid crystal display element is configured to operate as a phase modulation liquid crystal element in the effective pixel region and as a brightness modulation liquid crystal element in the peripheral region. (6) The liquid crystal display element according to any one of (1) to (5), wherein the peripheral drive electrode includes a plurality of electrodes. (7) The liquid crystal display element according to (6), wherein periodically alternating drive voltages are applied between adjacent electrodes in the plurality of electrodes of the peripheral drive electrode.(8) A display device including a liquid crystal display element and a projection optical system that projects an image generated by the liquid crystal display element, wherein the liquid crystal display element comprises: a first substrate; a second substrate disposed opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a first electrode portion formed in an effective pixel region of the first substrate and in a peripheral region of the effective pixel region of the first substrate; a second electrode portion having a pixel electrode portion formed in the effective pixel region of the second substrate and a peripheral drive electrode formed in the peripheral region of the second substrate; a first alignment film formed in the effective pixel region of each of the first substrate and the second substrate, and having an alignment direction at a first azimuth angle; and a second alignment film formed in the peripheral region of each of the first substrate and the second substrate, and having an alignment direction at a second azimuth angle that is 45° different from the first azimuth angle. (9) The display device according to (8), further including an analyzer arranged on the output side of the light from the liquid crystal display element.

[0065] This application claims priority based on Japanese Patent Application No. 2021-205013, filed on December 17, 2021, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0066] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A liquid crystal display element comprising: a first substrate; a second substrate disposed opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a first electrode portion formed in an effective pixel area of ​​the first substrate and in a peripheral area of ​​the effective pixel area of ​​the first substrate; a second electrode portion having a pixel electrode portion formed in the effective pixel area of ​​the second substrate and a peripheral drive electrode portion formed in the peripheral area of ​​the second substrate; a first alignment film formed in the effective pixel area of ​​each of the first substrate and the second substrate, the alignment direction of which is at a first azimuth angle; and a second alignment film formed in the peripheral area of ​​each of the first substrate and the second substrate, the alignment direction of which is at a second azimuth angle that is 45° different from the first azimuth angle.

2. A liquid crystal display element according to claim 1, wherein the first azimuth angle is a direction tilted at 45° with respect to the polarization direction of the incident light, and the second azimuth angle is parallel or perpendicular to the polarization direction of the incident light.

3. The liquid crystal display element according to claim 2, which is configured to operate as a luminance modulation type liquid crystal element in the effective pixel region and as a phase modulation type liquid crystal element in the peripheral region.

4. A liquid crystal display element according to claim 1, wherein the first azimuth angle is parallel to the polarization direction of the incident light, and the second azimuth angle is inclined at 45° to the polarization direction of the incident light.

5. The liquid crystal display element according to claim 4, which is configured to operate as a phase modulation type liquid crystal element in the effective pixel region and as a brightness modulation type liquid crystal element in the peripheral region.

6. The liquid crystal display element according to claim 1, wherein the peripheral drive electrode section includes a plurality of electrodes.

7. The liquid crystal display element according to claim 6, wherein a driving voltage that alternates periodically is applied between adjacent electrodes in the plurality of electrodes of the peripheral driving electrode section.

8. A display device comprising: a liquid crystal display element; and a projection optical system for projecting an image generated by the liquid crystal display element, wherein the liquid crystal display element comprises: a first substrate; a second substrate disposed opposite the first substrate so as to sandwich a liquid crystal layer containing a plurality of liquid crystal molecules between the first substrate and the second substrate; a first electrode portion formed in an effective pixel region of the first substrate and in a peripheral region of the effective pixel region of the first substrate; a second electrode portion having a pixel electrode portion formed in the effective pixel region of the second substrate and a peripheral drive electrode portion formed in the peripheral region of the second substrate; a first alignment film formed in the effective pixel region of each of the first substrate and the second substrate, and having an alignment direction at a first azimuth angle; and a second alignment film formed in the peripheral region of each of the first substrate and the second substrate, and having an alignment direction at a second azimuth angle that is 45° different from the first azimuth angle.

9. The display device according to claim 8, further comprising an analyzer arranged on the light output side of the liquid crystal display element.