Display device

Abstract

Display device equipped with: a display panel that modulates a first polarization component, a first viewing angle control panel having a first liquid crystal layer containing hybrid aligned liquid crystal molecules, a second viewing angle control panel having a second liquid crystal layer containing twisted liquid crystal molecules, and a polarization axis rotating element provided between the first viewing angle control field and the second viewing angle control field, wherein the first viewing angle control panel is provided between the polarization axis rotating element and the display panel, in plan view, the initial alignment direction of the horizontally aligned first liquid crystal molecules among the liquid crystal molecules of the first liquid crystal layer is substantially orthogonal to the initial alignment direction of the second liquid crystal molecules positioned in a middle layer among the liquid crystal molecules of the second liquid crystal layer, a second polarization axis of a second polarization component penetrating the first viewing angle control panel is substantially parallel to a first polarization axis of the first polarization component, a third polarization axis of a third polarization component penetrating the second viewing angle control panel is different from the second polarization axis,and a polarization direction of light passing through the polarization axis rotating element is rotated from the third to the second polarization axis.,

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority based on Japanese Application No. 2021-065406 filed on April 7, 2021, the entire contents of which are incorporated herein by reference. Area

[0002] The embodiment of the present invention relates to a display device. background

[0003] The latter display devices require varying the viewing angle to achieve a specific contrast ratio. For example, for displays installed in vehicles such as cars, the viewing angle should be controlled so that a displayed image is visible from the passenger side, while the displayed image is not visible from the driver's side, e.g., when the driver is driving.

[0004] For applications requiring viewing angle control, several techniques for using twisted nematic liquid crystal elements have been proposed. For example, patent DE 10 2019 003 383 A1 discloses a switchable viewing angle control device for a private viewing display system. Brief explanation of the drawings

[0005] It shows: Fig. 1 is a view of a configuration example of a display device DSP of an embodiment; Fig. 2 a sectional view of a training example of the Fig. 1 shown display device DSP; Fig. 3 is a view illustrating the axial angle of each optical element which Fig. 1 forms the display device DSP; Fig. 4 is a view showing a configuration example of a first viewing angle control panel 1; Fig. 5 is a view illustrating the operation of a first viewing angle control panel 1; Fig. 6 is a view showing a configuration example of a second viewing angle control panel 2; Fig. 7 shows a plan view of an example of the pixel layout in a display panel PNL; Fig. 8 is a view showing a formation example of the display panel PNL; Fig. 9 is a view showing the alignment state of liquid crystal molecules LM2 in the off state in which no voltage is applied to a second liquid crystal layer LC2; Fig. 10 is a view showing the alignment state of liquid crystal molecules LM2 in the on state in which the voltage is applied to the second liquid crystal layer LC2; Fig. 11 is a diagram showing the viewing angle behavior of the second viewing angle control panel 2 in the off and on states; Fig. 12 is a diagram showing the viewing angle behavior of the first viewing angle control panel 1 in the off state; Fig. 13 is a diagram showing the viewing angle behavior of the first viewing angle control panel 1 in the on state; Fig. 14 is a view showing another configuration example of the display device DSP of the present embodiment; Fig. Fig. 15 is a view showing the axial angle of each optical element which has the Fig. 14 forms the display device DSP; Fig. 16 is a view showing a configuration example of a third viewing angle control panel 3; Fig. 17 is a view showing another embodiment of the third view angle control panel 3; Fig. 18 is a view showing another embodiment of the display device DSP of the present invention; Fig. 19 shows a comparative example of the display device DSP; Fig. 20 shows the viewing angle behavior of the display device DSP; Fig. 21 shows the frontal ratio based on the Fig. 20 simulation results shown; Fig. 22 shows the viewing angle behavior of the display device DSP; Fig. 23 shows an application example of the display device DSP. Detailed description

[0006] The purpose of the present embodiment is to provide a display device that can control a viewing angle.

[0007] According to one embodiment, the display device is provided with: a display panel that modulates a first polarization component, a first viewing angle control panel having a first liquid crystal layer containing hybrid aligned liquid crystal molecules, a second viewing angle control panel having a second liquid crystal layer containing twisted liquid crystal molecules, and a polarization axis rotating element provided between the first viewing angle control field and the second viewing angle control field, wherein the first viewing angle control panel is provided between the polarization axis rotating element and the display panel, in plan view, the initial alignment direction of the horizontally aligned first liquid crystal molecules among the liquid crystal molecules of the first liquid crystal layer is substantially orthogonal to the initial alignment direction of the second liquid crystal molecules positioned in a middle layer among the liquid crystal molecules of the second liquid crystal layer, a second polarization axis of a second polarization component penetrating the first viewing angle control panel is substantially parallel to a first polarization axis of the first polarization component, a third polarization axis of a third polarization component penetrating the second viewing angle control panel is different from the second polarization axis,and a polarization direction of light passing through the polarization axis rotating element is rotated from the third to the second polarization axis.

[0008] According to one embodiment, a display device capable of controlling a viewing angle may be provided.

[0009] The present embodiment will be explained below with reference to the drawings. The disclosure is merely an example, and the subject matter readily apparent to those skilled in the art regarding appropriate modification while maintaining the gist of the invention is naturally included within the scope of the present invention. To further clarify the explanation, the drawings may also schematically show the width, thickness, shape, etc. of the individual parts in comparison with the actual shape. However, this is merely an example and does not limit the interpretation of the present invention.In the present description and the respective drawings, the components that perform the same or similar functions as with reference to the previously mentioned drawings are designated by the same reference numerals, and overlapping detailed explanations may be omitted according to the circumstances. <Erstes Ausbildungsbeispiel>

[0010] Fig. 1 is a view showing a configuration example of a display device DSP of the present embodiment.

[0011] The display device DSP is provided with a display panel PNL, a first viewing angle control panel 1, a second viewing angle control panel 2, a polarization axis rotating element 100, first to fifth polarizing plates POL1 to POL5, and an illumination device IL.

[0012] The first viewing angle control panel 1 is provided between the display panel PNL and the polarization axis rotating element 100. The second viewing angle control panel 2 is provided between the polarization axis rotating element 100 and the illumination device IL. The polarization axis rotating element 100 is provided between the first viewing angle control panel 1 and the second viewing angle control panel 2.

[0013] The first polarizing plate POL1 is provided on the front side of the display panel PNL (or on the side of the viewing position at which the display device DSP is viewed). The second polarizing plate POL2 is provided between the display panel PNL and the first viewing angle control panel 1. The third polarizing plate POL3 is provided between the first viewing angle control panel 1 and the polarization axis rotating element 100. The fourth polarizing plate POL4 is provided between the polarization axis rotating element 100 and the second viewing angle control panel 2. The fifth polarizing plate POL5 is provided on the back side of the second viewing angle control panel 2 (or between the second viewing angle control panel 2 and the illuminator IL).

[0014] The details of the first viewing angle control panel 1 and the second viewing angle control panel 2 will be described later. It is also possible for the second viewing angle control panel 2 to be provided between the display panel PNL and the polarization axis rotating element 100, and the first viewing angle control panel 1 to be provided between the polarization axis rotating element 100 and the illuminator IL.

[0015] In this way, the display device DSP of the present embodiment is provided with various viewing angle control panels between the display panel PNL and the illuminator IL.

[0016] Fig. 2 shows a sectional view of a training example of the Fig. 1. The first direction X, the second direction Y, and the third direction Z shown here are orthogonal to each other, but may intersect at an angle other than 90 degrees. For example, the first direction X and the second direction Y correspond to the directions parallel to a substrate included in the DSP display device, and the third direction Z corresponds to the thickness direction of the DSP display device.

[0017] The display panel PNL is, for example, a liquid crystal screen and is provided with a first substrate SUB1, a second substrate SUB2, and a liquid crystal layer LC. The liquid crystal layer LC is held between the first substrate SUB1 and the second substrate SUB2 and sealed with a gasket SE. The display panel PNL explained here is, for example, designed such that the alignment state of the liquid crystal molecules contained in the liquid crystal layer LC is controlled by an electric field along the principal plane of the substrate. The display panel PNL is not limited to the example shown and can also be designed such that it controls the alignment state of the liquid crystal molecules by an electric field along the normal to the principal plane of the substrate. The principal plane of the substrate here corresponds to the XY plane, which is defined by the first direction X and the second direction Y.

[0018] The first substrate SUB1 is positioned on the front side of the second substrate SUB2. The first substrate SUB1 is provided with an insulating substrate 10 and an alignment film AL1.

[0019] The second substrate SUB2 is provided with an insulating substrate 20, an insulating film 21, a common electrode CE, a plurality of pixel electrodes PE, and an alignment film AL2. The common electrode CE is provided between the insulating substrate 20 and the insulating film 21. The plurality of pixel electrodes PE are provided between the insulating film 21 and the alignment film AL2. In the display area DA where images are displayed, the plurality of pixel electrodes PE are superimposed on the single common electrode CE via the insulating film 21. The pixel electrodes PE and the common electrode CE are controlled to apply a voltage to the liquid crystal layer LC. The alignment film AL1 and the alignment film AL2 are in contact with the liquid crystal layer LC.The alignment film AL1 and the alignment film AL2 are, in one example, parallel alignment films having an alignment regulating force substantially parallel to the XY plane, but they may also be vertical alignment films.

[0020] Although only the main parts of the display panel PNL are simplified here, the first substrate SUB1 is further provided with a light-shielding layer, a color filter layer, an overcoat layer, and a spacer, etc. Furthermore, the second substrate SUB2 is provided with a plurality of scanning lines, a plurality of signal lines, a switching element electrically connected to each pixel electrode PE, various insulating films, etc.

[0021] The first viewing angle control panel 1 is, for example, a liquid crystal display and is provided with a third substrate SUB3, a fourth substrate SUB4, and a first liquid crystal layer LC1. The first liquid crystal layer LC1 is held between the third substrate SUB3 and the fourth substrate SUB4 and sealed by the gasket SE1. The first liquid crystal layer LC1 contains hybrid-aligned liquid crystal molecules, as described later.

[0022] The third substrate SUB3 is positioned on the front side of the fourth substrate SUB4. The third substrate SUB3 is provided with an insulating substrate 30, a first transparent electrode TE1, and an alignment film AL3. The first transparent electrode TE1 is formed substantially over the entire area of ​​a valid viewing angle control area AA1 and is provided between the insulating substrate 30 and the alignment film AL3.

[0023] The fourth substrate SUB4 is provided with an insulating substrate 40, a second transparent electrode TE2, and an alignment film AL4. The second transparent electrode TE2 is formed substantially over the entire area of ​​the valid viewing angle control area AA1 and is provided between the insulating substrate 40 and the alignment film AL4. The alignment film AL3 and the alignment film AL4 are in contact with the first liquid crystal layer LC1. One of these alignment films AL3 and AL4 is a horizontal alignment film, and the other is a vertical alignment film.

[0024] The first transparent electrode TE1 overlies the second transparent electrode TE2 via the first liquid crystal layer LC1. The first transparent electrode TE1 and the second transparent electrode TE2 are controlled such that a voltage is applied to the first liquid crystal layer LC1.

[0025] The second viewing angle control panel 2 is, for example, a liquid crystal display provided with a fifth substrate SUB5, a sixth substrate SUB6, and a second liquid crystal layer LC2. The second liquid crystal layer LC2 is held between the fifth substrate SUB5 and the sixth substrate SUB6 and sealed with a gasket SE2. The second liquid crystal layer LC2 contains twisted liquid crystal molecules, as described later.

[0026] The fifth substrate SUB5 is positioned on the front side of the sixth substrate SUB6. The fifth substrate SUB5 is provided with an insulating substrate 50, a third transparent electrode TE3, and an alignment film AL5. The third transparent electrode TE3 is formed substantially over the entire area of ​​a valid viewing angle control area AA2 and is provided between the insulating substrate 50 and the alignment film AL5.

[0027] The sixth substrate SUB6 is provided with an insulating substrate 60, a fourth transparent electrode TE4, and an alignment film AL6. The fourth transparent electrode TE4 is formed substantially over the entire area of ​​the valid viewing angle control area AA2 and is provided between the insulating substrate 60 and the alignment film AL6. The alignment film AL5 and the alignment film AL6 are in contact with the second liquid crystal layer LC2. These alignment film AL5 and the alignment film AL6 are horizontal alignment films. The second liquid crystal layer LC2, as described later, has the optical rotatability to rotate the polarization axis of the polarization component, which is linearly polarized light.

[0028] The third transparent electrode TE3 overlies the fourth transparent electrode T via the second liquid crystal layer LC2. The third transparent electrode TE3 and the fourth transparent electrode TE4 are controlled such that a voltage is applied to the second liquid crystal layer LC2.

[0029] The first transparent electrode TE1, the second transparent electrode TE2, the third transparent electrode TE3 and the fourth transparent electrode TE4 are each, for example, single sheet-shaped electrodes, but may also be electrodes divided into a plurality of electrodes along at least one of the first direction X and the second direction Y.

[0030] Here, the relationship between the display field PNL, the first viewing angle control field 1 and the second viewing angle control field 2 is considered.

[0031] The liquid crystal layer LC, the first liquid crystal layer LC1, and the second liquid crystal layer LC2 are superimposed in the third direction Z. The display area DA, the valid area AA1, and the valid area AA2 are superimposed in the third direction Z. The common electrode CE, the plurality of pixel electrodes PE, the first transparent electrode TE1, the second transparent electrode TE2, the third transparent electrode TE3, and the fourth transparent electrode TE4 are superimposed in the third direction Z.

[0032] The insulating substrates 10, 20, 30, 40, 50, 60 are transparent substrates, such as glass or resin substrates. The insulating substrates 10 and 20 can be glass substrates, for example, and the insulating substrates 30 and 40 can be resin substrates.

[0033] In addition, the insulating substrates 10 and 40 may be glass substrates and the insulating substrates 20 and 30 may be resin substrates.

[0034] The common electrode CE, the pixel electrode PE, the first transparent electrode TE1, the second transparent electrode TE2, the third transparent electrode TE3 and the fourth transparent electrode TE4 are transparent electrodes made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0035] The first polarizing plate POL1 is bonded to the insulating substrate 10, the second polarizing plate POL2 is bonded to at least one of the insulating substrate 20 and the insulating substrate 30, the third polarizing plate POL3 is bonded to the insulating substrate 40, the fourth polarizing plate POL4 is bonded to the insulating substrate 50, and the fifth polarizing plate POL5 is bonded to the insulating substrate 60. These first to fifth polarizing plates POL1 to POL5 have an adhesive on one side of a preformed film, but can also be formed directly on the surface of the insulating substrate.

[0036] The polarization axis rotating member 100 may be bonded to at least one of the third polarizing plate POL3 and the fourth polarizing plate POL4, or may be formed integrally with the third polarizing plate POL3 or the fourth polarizing plate POL4.

[0037] In such a display device DSP, the illumination light (unpolarized light) emitted from the illumination device IL travels along the third direction Z, and after sequentially passing through the second viewing angle control panel 2, the polarization axis rotating element 100, and the first viewing angle control panel 1, the display panel PNL is illuminated.

[0038] Specifically, if the illumination light emitted by the illumination device IL is unpolarized, the fifth polarization plate POL5 allows some polarization components of the illumination light to pass through.

[0039] The second viewing angle control panel 2 rotates the polarization axis of the polarization components penetrating the fifth polarization plate POL5 in the second liquid crystal layer LC2. The fourth polarization plate POL4 allows the polarization components penetrating the second viewing angle control panel 2 to pass through.

[0040] The polarization axis rotating element 100 allows the polarization components penetrating the fourth polarization plate POL4 to pass through. The third polarization plate POL3 allows the polarization components penetrating the polarization axis rotating element 100 to pass through.

[0041] The first viewing angle control field 1 modulates and allows the polarization components penetrating the third polarization plate POL3 to pass through the first liquid crystal layer LC1. The second polarization plate POL2 allows the polarization components penetrating the first viewing angle control field 1 to pass through.

[0042] The display panel PNL is illuminated with the polarization component penetrating the second polarization plate POL2 and modulates the polarization components in the liquid crystal layer LC. The first polarization plate POL1 allows at least a portion of the polarization components penetrating the display panel PNL to pass through.

[0043] If the polarization component modulated by the display field PNL is considered as the first polarization component and the polarization component penetrating the first viewing angle control field 1 is considered as the second polarization component, the second polarization axis of the second polarization component runs substantially parallel to a first polarization axis of the first polarization component.

[0044] If the polarization component penetrating the second viewing angle control field 2 is regarded as a third polarization component, the third polarization axis of the third polarization component differs from the second polarization axis.

[0045] For example, each of the first polarization component, the second polarization component, and the third polarization component is linearly polarized light with a polarization axis in the XY plane. In the XY plane, when the first direction X is the reference azimuth, the first polarization component has a first polarization axis in an azimuth that forms a predetermined angle with the first direction, the second polarization component has a second polarization axis that is substantially parallel to the first polarization axis with respect to the first direction X, and the third polarization component has a third polarization axis in an azimuth that is different from the second polarization axis with respect to the first direction X.

[0046] The polarization axis rotating element 100 rotates the polarization axis of light from the second viewing angle control field 2 to the first viewing angle control field 1. The polarization axis rotating element 100 is, for example, an optical film (phase difference plate) formed to impart a phase difference of half a wavelength to the linearly polarized light passing therethrough.

[0047] The polarization axis rotating element 100 can be a single optical film or a multilayer optical film. The polarization axis rotating element 100 is not limited to the optical film and can also be an element with optical rotation capability, such as a twisted nematic liquid crystal element, as long as it can exhibit a polarization axis rotating function.

[0048] With such a polarization axis rotating element 100, the third polarization axis of the third polarization component penetrating the second viewing angle control panel 2 and the fourth polarizing plate POL4 rotates to coincide with the second polarization axis. Therefore, the absorption of the illumination light penetrating the second viewing angle control panel 2 by the third polarizing plate POL3 is suppressed, and a reduction in the luminance of the illumination light reaching the display panel PNL can be suppressed.

[0049] Fig. 3 is a view illustrating the axial angle of each optical element which forms the Fig. 1. Here, the azimuth of the arrowhead indicating the first direction X (X-axis) in the XY plane is considered the reference azimuth, and a counterclockwise angle with respect to the reference azimuth is considered a positive angle.

[0050] The first polarization plate POL1 has a first absorption axis A1 and a first transmission axis T1, which are substantially orthogonal to each other. The second polarization plate POL2 has a second absorption axis A2 and a second transmission axis T2, which are substantially orthogonal to each other. The polarization axis rotating element 100 has a fast axis F. The third polarization plate POL3 has a third transmission axis T3. The fourth polarization plate POL4 has a fourth transmission axis T4. The fifth polarization plate POL5 has a fifth transmission axis T5.

[0051] Although illustration is omitted, the slow phase axis of the polarization axis rotating element 100 is substantially orthogonal to the fast axis in the XY plane. Furthermore, the absorption axis of the third polarizing plate POL3 is substantially orthogonal to the third transmission axis T3, the absorption axis of the fourth polarizing plate POL4 is substantially orthogonal to the fourth transmission axis T4, and the absorption axis of the fifth polarizing plate POL5 is substantially orthogonal to the fifth transmission axis T5.

[0052] The respective transmission axes of the first polarization plate POL1 and the second polarization plate POL2, which clamp the display panel PNL, are orthogonal to each other. The first absorption axis A1, for example, runs substantially parallel to the first direction X and is positioned at an azimuth of 0°. The first transmission axis T1 is positioned at an azimuth of 90°. The second absorption axis A2 is substantially orthogonal to the first absorption axis A1 and is positioned at an azimuth of 90°. The second transmission axis T2 is substantially orthogonal to the first transmission axis T1 and is positioned at an azimuth of 0°.

[0053] The respective transmission axes of the second polarization plate POL2 and the third polarization plate POL3, which clamp the first viewing angle control panel 1, are parallel to each other. This means that the transmission axis T3 is positioned at an azimuth of 0°.

[0054] The respective transmission axes of the fourth polarization plate POL4 and the fifth polarization plate POL5, which clamp the second viewing angle control panel 2, are parallel to each other. The fourth transmission axis T4 is positioned at a different azimuth than the third transmission axis, namely at an azimuth of 45°. The fifth transmission axis T5 is essentially orthogonal to the fourth transmission axis T4 and is positioned at an azimuth of 135°.

[0055] Here, an azimuth of 0° corresponds to an azimuth over 0° to 180° in the XY plane, an azimuth of 90° corresponds to an azimuth from 90° to 270° in the XY plane, an azimuth of 45° corresponds to an azimuth from 45° to 225° in the XY plane, and an azimuth of 135° corresponds to an azimuth from 135° to 315° in the XY plane.

[0056] When the light in such a display device DSP travels along the third direction Z, linearly polarized light passing through the fifth polarizing plate POL5 has a polarization axis along the fifth transmission axis T5, and linearly polarized light (third polarization component) passing through the fourth polarizing plate POL4 via the viewing angle control panel 2 has a third polarization axis along the fourth transmission axis T4. That is, the third polarization axis is positioned at an azimuth of 45° to the X-axis (or azimuth of 45° to 225°).

[0057] Linearly polarized light (second polarization component) that passes through the first viewing angle control panel 1 after passing through the third polarization plate POL3 has a second polarization axis along the third transmission axis T3. That is, the second polarization axis is positioned at an azimuth of 0° (or azimuth of 0° - 180° or X-axis direction).

[0058] The fast axis F or the slow axis of the polarization axis rotating element 100 is positioned in the XY plane at an azimuth between the azimuth of the second polarization axis and the azimuth of the third polarization axis. Alternatively, the fast axis F and the slow axis are positioned at an azimuth between the azimuth of the third transmission axis T3 and the azimuth of the fourth transmission axis T4. That is, in the illustrated example, the fast axis F or the slow axis is positioned at an azimuth of 22.5° (or at an azimuth of 22.5° to 202.5°).

[0059] When the third transmission axis T3 is positioned at an azimuth of 90° and the fourth transmission axis T4 is positioned at an azimuth of 45°, the polarization axis rotating element 100 is arranged such that the fast axis F or the slow axis is positioned at an azimuth of 67.5° (or at an azimuth of 67.5° to 247.5°).

[0060] The polarization axis rotating element 100 corresponds to a half-wave plate as described above, so that when the polarization axis of the incident light is positioned at an azimuth of θ° to the fast axis, the polarization axis rotating element 100 has a function of rotating the polarization axis by 2*θ°. Therefore, when the third polarization component penetrating the fourth polarization plate POL4 penetrates the polarization axis rotating element 100, the third polarization axis rotates to coincide with the second polarization axis. That is, the third polarization component is converted into the second polarization component at the polarization axis rotating element 100. The second polarization component penetrating the polarization axis rotating element 100 is hardly absorbed by the third polarization plate POL3, and the display panel PNL is illuminated with the second polarization component via the first viewing angle control panel 1.

[0061] The first polarization component with which the display panel PNL is illuminated is appropriately modulated in the liquid crystal layer LC, and at least a portion of it penetrates the first polarizing plate POL1, forming a display image. Linearly polarized light that penetrates the first polarizing plate POL1 has a polarization axis along the first transmission axis T1. That is, the polarization axis of the linearly polarized light that penetrates the first polarizing plate POL1 is positioned at an azimuth of 90° (or azimuth from 90° to 270°). Therefore, a display image can be seen even when the display device DSP is viewed through polarized sunglasses.

[0062] Next, the first view angle control field 1 is explained.

[0063] Fig. 4 is a view illustrating a configuration example of the first viewing angle control panel 1. This view shows an initial alignment state of the liquid crystal molecules LM1 in the off state, in which no voltage is applied to the first liquid crystal layer LC1 between the third alignment film AL3 and the fourth alignment film AL4. This example explains the case where the alignment film AL4 is a vertically aligned film and the alignment film AL3 is a horizontally aligned film. As described above, it is also possible for the alignment film AL3 to be a vertically aligned film and the alignment film AL4 to be a horizontally aligned film.

[0064] Alignment processing is required for the alignment film AL3, which is a horizontally aligned film, while alignment processing is not required for the alignment film AL4, which is a vertically aligned film. However, from the viewpoint of maintaining a stable alignment state, it is desirable to perform alignment processing on the alignment film AL4. In this case, the alignment processing direction AD4 of the alignment film AL4 is substantially parallel and opposite to the alignment processing direction AD3 of the alignment film AL3. The alignment processing may be a rubbing treatment or light alignment.

[0065] In the Fig. In the embodiment shown in Figure 4, the alignment processing direction AD3 and the alignment processing direction AD4 are positioned at an azimuth of 90° to 270°. The alignment processing direction AD4 is substantially orthogonal to the third transmission axis T3, and the alignment processing direction AD3 is substantially orthogonal to the second transmission axis T2. The second transmission axis T2 and the third transmission axis T3 can be positioned at an azimuth of 0° to 180°, with the second transmission axis T2 and the third transmission axis T3 being parallel to the alignment processing direction AD3 and the alignment processing direction AD4.

[0066] In the first liquid crystal layer LC1, the liquid crystal molecules LM1, which are arranged along the third direction Z, are hybridly aligned. In Fig. Figure 4 shows a schematic top view of the plurality of liquid crystal molecules LM1. The liquid crystal molecules LMA adjacent to the third polarization plate POL3 and the fourth substrate SUB4 are vertically aligned such that their longitudinal axis runs along the normal of the substrate (third direction).

[0067] The liquid crystal molecules LMB adjacent to the second polarizing plate POL2 and the third substrate SUB3 are aligned horizontally along the XY plane such that their longitudinal axis runs along the alignment processing direction AD3. Alternatively, the liquid crystal molecules LMB are aligned in an azimuth orthogonal to the second transmission axis T2 and the third transmission axis T3. That is, the liquid crystal molecules LMB are aligned in an azimuth of 90° to 270°. Furthermore, the liquid crystal molecules LMB are tilted such that the end of the tip of the arrow indicating the alignment processing direction AD3 is spaced from the third substrate SUB3 (alternatively, the liquid crystal molecules LMB are tilted such that the end on the reverse side of the arrow indicating the alignment processing direction AD3 is adjacent to the third substrate SUB3).

[0068] The arrow indicating the alignment processing direction AD3 and the arrow indicating the alignment processing direction AD4 can also point in opposite directions. Furthermore, the liquid crystal molecules LMA can be positioned at an azimuth of 90° to 270°, and the liquid crystal molecules LMB can be aligned vertically.

[0069] Fig. 5 is a view illustrating the operation of the first viewing angle control panel 1. The section shown on the left side of the drawing shows the off state (OFF) in which no potential difference is generated between the first transparent electrode TE1 and the second transparent electrode TE2, and the section shown on the right side of the drawing shows the on state (ON) in which a potential difference is generated between the first transparent electrode TE1 and the second transparent electrode TE2.

[0070] The first liquid crystal layer LC1 is formed with a liquid crystal material with negative dielectric constant anisotropy (negative-type liquid crystal material). The plurality of liquid crystal molecules LM1 arranged along the third direction Z includes the liquid crystal molecules LMA and LMB. In the off state, the liquid crystal molecules LMA near the alignment film AL4 have a substantially vertical alignment, while the liquid crystal molecules LMB near the alignment film AL3 have a substantially horizontal alignment. Furthermore, in the liquid crystal molecules LM1, each tilt angle between the liquid crystal molecules LMA and the liquid crystal molecules LMB continuously changes. The liquid crystal molecules LM1 are thus initially aligned to have a hybrid alignment.

[0071] In the switched-on state, the long axis of the liquid crystal molecules LM1 in negative liquid crystal materials is aligned such that it crosses the electric field. This means that the liquid crystal molecules LM1 are each aligned horizontally.

[0072] Here, the case where the first liquid crystal layer LC1 as the first viewing angle control panel 1 is made of a negative-type liquid crystal material will be explained. However, the first liquid crystal layer LC1 may also be formed of a positive-type liquid crystal material having positive dielectric constant anisotropy. The first viewing angle control panel 1 may also be a liquid crystal display panel employing an electrically controlled birefringence mode. In this case, too, the alignment processing direction AD4 of the alignment film AL4 and the alignment processing direction AD3 of the alignment film AL3 are set to be parallel and opposite to each other and positioned at an azimuth of 90° to 270°.

[0073] Next, the second viewing angle control field 2 is explained.

[0074] Fig. 6 is a view showing a configuration example of the second viewing angle control panel 2. Here, the initial alignment state of the liquid crystal molecules LM2 is in the off state in which no voltage is applied to the second liquid crystal layer LC2 between the alignment film AL5 and the alignment film AL6.

[0075] The alignment processing direction AD6 of the alignment film AL6 is substantially orthogonal to the alignment processing direction AD5 of the alignment film AL5. Fig. In the embodiment shown in Figure 6, the alignment processing direction AD6 is substantially parallel to the fifth transmission axis T5, and the alignment processing direction AD5 is substantially parallel to the fourth transmission axis T4. That is, the alignment processing direction AD6 is positioned at an azimuth of 135°, and the alignment processing direction AD5 is positioned at an angle of 45°.

[0076] In the second liquid crystal layer LC2, the liquid crystal molecules LM2, which are arranged along the third direction Z, are aligned in a twisted manner. Fig. Figure 6 schematically shows the plurality of liquid crystal molecules LM2 in a top view. A chiral agent is added to the second liquid crystal layer LC2, and the liquid crystal molecules LM2 are formed in such a way that they are twisted counterclockwise from the fifth polarizing plate POL5 (or the sixth substrate SUB6) to the fourth polarizing plate POL4 (or the fifth substrate SUB5).

[0077] The liquid crystal molecules LMC adjacent to the fifth polarizing plate POL5 and the sixth substrate SUB6 are aligned such that their longitudinal axes run along the alignment processing direction AD6. Alternatively, the liquid crystal molecules LMC are aligned in an azimuth along the fifth transmission axis T5. That is, the liquid crystal molecules LMC are aligned at an azimuth of 135°. Furthermore, the liquid crystal molecules LMC are tilted (pre-tilted) such that the end on the tip side of the arrow indicating the direction of the alignment processing direction AD6 is spaced from the sixth substrate SUB6.

[0078] The liquid crystal molecules LMD adjacent to the fourth polarizing plate POL4 and the fifth substrate SUB5 are aligned such that their long axes run along the alignment processing direction AD5. Alternatively, the liquid crystal molecules LMD are aligned in azimuth along the fourth transmission axis T4. That is, the liquid crystal molecules LMD are aligned at an angle of 45°. Furthermore, the liquid crystal molecules LMD are tilted such that the end on the tip side of the arrow indicating the alignment processing direction AD5 is spaced from the fifth substrate SUB5 (or the end on the reverse side of the arrow indicating the alignment processing direction AD5 is adjacent to the fifth substrate SUB5).

[0079] The liquid crystal molecules (second liquid crystal molecules) LME in the substantially central (middle layer) in the third direction (thickness direction) Z of the second liquid crystal layer LC2 are aligned such that their longitudinal axis runs along the first direction X. Such an alignment direction of the liquid crystal molecules LME and the Fig. The alignment direction of the liquid crystal molecules LMB shown in Figure 4 is essentially orthogonal to each other in the XY plane.

[0080] In addition, the long axis of the liquid crystal molecules LME in the XY plane is essentially parallel to the first absorption axis A1 of the Fig. 3 shown first polarization plate POL1.

[0081] At least one of the arrows indicating the alignment processing direction AD5 and the arrow indicating the alignment processing direction AD6 may point in opposite directions. Furthermore, the alignment processing direction AD6 and the fifth transmission axis T5 may be positioned at an angle of 45°, and the alignment processing direction AD5 and the fourth transmission axis T4 may be positioned at an azimuth of 135°. Furthermore, the liquid crystal molecules LM2 may be aligned clockwise in the third direction Z, as long as the liquid crystal molecules LME are aligned along the first direction X.

[0082] Next, the PNL display field is explained. Fig. Figure 7 shows a top view of an example of the pixel layout in the display panel PNL. Only the components necessary for explanation are shown here. The second substrate SUB2 is provided with a plurality of scanning lines G, a plurality of signal lines S, a plurality of switching elements SW, and a plurality of pixel electrodes PE1 and PE2.

[0083] The plurality of scanning lines G each extend linearly along the first direction X and are spaced apart in the second direction Y. The plurality of signal lines S each extend generally along the second direction Y and are spaced apart in the first direction X. The switching element SW is electrically connected to one of the scanning lines G and one of the signal lines S. Each of the pixel electrodes PE1 and PE2 is electrically connected to one of the switching elements SW.

[0084] A plurality of pixel electrodes PE1 are lined up along the first direction X. The pixel electrode PE1 has a band electrode Pa1 overlying the common electrode CE. The band electrode Pa1 extends along a direction D1 that is different from the first direction X and the second direction Y.

[0085] A plurality of pixel electrodes PE2 are lined up along the first direction X. The pixel electrode PE2 has a strip electrode Pa2 overlying the common electrode CE. The strip electrode Pa2 extends in a direction D2 that differs from the direction D1. The number of strip electrodes Pa1 and Pa2 can be one or three or more.

[0086] Fig. Figure 8 is a view illustrating a formation example of the display panel PNL. This shows the initial alignment state of the off-state liquid crystal molecules LM, in which no voltage is applied to the liquid crystal layer LC between the alignment film AL1 and the alignment film AL2.

[0087] The alignment processing direction AD1 of the alignment film AL1 and the alignment processing direction AD2 of the alignment film AL2 are substantially parallel and opposite to each other. The alignment processing direction AD1 and the alignment processing direction AD2 are, for example, parallel to the first transmission axis T1. That is, in the XY plane, the tip of the arrow indicating the direction of the alignment processing direction AD2 is positioned at an azimuth of 90°, and the tip of the arrow indicating the alignment processing direction AD1 is positioned at an azimuth of 270°. In the liquid crystal layer LC, the liquid crystal molecules LM, which are lined up along the third direction Z, are homogeneously aligned. The liquid crystal molecules LM are aligned such that their longitudinal axis runs along the second direction Y.

[0088] The alignment processing direction AD1 and the alignment processing direction AD2 may be substantially orthogonal to the first transmission axis T1. Furthermore, the second transmission axis T2 may be positioned at an azimuth of 90°, and the first transmission axis T1 may be positioned at an azimuth of 0°. As described above, however, from the perspective of viewing the displayed image through polarized sunglasses, it is desirable that the first transmission axis T1 be positioned at an azimuth of 90° and the second transmission axis T2 be positioned at an azimuth of 0°.

[0089] Next, the viewing angle behavior of the second viewing angle control field 2 is explained.

[0090] Fig. Figure 9 is a view showing the alignment state of liquid crystal molecules LM2 in the off state, in which no voltage is applied to the second liquid crystal layer LC2. The long axis LX of the liquid crystal molecules LME is substantially parallel to the first direction X and substantially parallel to the XY plane. As shown in Fig. 6 etc., when the fourth polarizing plate POL4 and the fifth polarizing plate POL5 clamping the second viewing angle control panel 2 are arranged in a crossed Nikol relationship, the maximum degree of transparency is obtained when turning off.

[0091] Fig. Figure 10 is a view showing the alignment state of the liquid crystal molecules LM2 in the on state in which the voltage is applied to the second liquid crystal layer LC2. As the voltage applied to the second liquid crystal layer LC2 increases, the degree of transparency decreases. When the voltage applied to the second liquid crystal layer LC2 is the maximum voltage, Fig. 10 shows the alignment state when applying a voltage of approximately half the maximum voltage to the second liquid crystal layer LC2. Here, the longitudinal axis LX of the liquid crystal molecules LME is essentially parallel to the first direction X and inclined to the XY plane.

[0092] In the second viewing angle control panel 2 in such a turned-on state, the respective degrees of transparency are asymmetrical depending on the case where the viewing position on the right side of the drawing (on the tip side of the arrow indicating the first direction X) is inclined with respect to the normal direction (third direction Z) of the display device, and the case where the viewing position on the left side of the drawing (on the back side of the arrow indicating the first direction X) is inclined with respect to the normal direction.

[0093] Fig. Figure 11 shows a graph showing the viewing angle behavior of the second viewing angle control panel 2 in the off and on states. The abscissa of the graph is the polar angle (°) to the normal of the display device, and corresponds to the first direction X in the above XY plane, i.e., the azimuth from 0° to 180°. The azimuth of 0° in the XY plane (tip of the arrow indicating the first direction X) is a positive angle, and the azimuth of 180° in the XY plane (rear end of the arrow indicating the first direction X) is a negative angle. The ordinate of the graph shows the luminance (relative value).

[0094] The conditions of the simulation explained here are as follows: The illumination light of the illumination device IL is unpolarized, the second viewing angle control panel 2 is sandwiched between the fourth polarization plate POL4 and the fifth polarization plate POL5, no other optical elements are provided, the drive voltage of the second liquid crystal layer LC2 in the on state is 2.5 V, and the wavelength of transmitted light is 550 nm.

[0095] Symbol A in the diagram corresponds to the viewing angle behavior in the off state. In the off state, a substantially symmetrical luminance distribution is obtained, even when the viewing position is tilted to the left with respect to the normal direction, or even when the viewing position is tilted to the right with respect to the normal direction.

[0096] The symbol B in the diagram corresponds to the viewing angle behavior in the on-state. When the viewing position is tilted to the right with respect to the normal direction, a luminance of approximately 20% or more is obtained in the on-state range from 0° to +50°. Conversely, when the viewing position is tilted to the left with respect to the normal direction in the diagram, the luminance is approximately 3% or less in the range of 30° or more (in the range of -30° to -80° in the diagram), and approximately 1% or less in the range of 40° or more (in the range of -40° to -80° in the diagram), which is essentially a light-shielding state.

[0097] Next, the viewing angle behavior of the first viewing angle control field 1 is explained.

[0098] Fig. Figure 12 shows a graph showing the viewing angle behavior of the first viewing angle control panel 1 in the off state. The abscissa of the graph represents the polar angle (°) with respect to the normal of the display device, and the ordinate of the graph represents the luminance (relative value).

[0099] The conditions of the simulation explained here are as follows. The illumination light from the illumination device IL is unpolarized, the first viewing angle control panel 1 is sandwiched between the second polarizing plate POL2 and the third polarizing plate POL3, no other optical elements are provided, and the wavelength of transmitted light is 550 nm. The anisotropy of the refractive index Δn in the first liquid crystal layer LC1 is 0.1482, and the first liquid crystal layer LC1 is made of a negative-type liquid crystal material. The applied voltage of the first liquid crystal layer LC1 is 0 V (off).

[0100] Here, the luminance versus polar angle was simulated for different thicknesses d of the first liquid crystal layer LC1. The thicknesses d were 5 µm, 15 µm, 25 µm, 35 µm, 45 µm, 55 µm, 65 µm, and 75 µm.

[0101] Under all conditions of thickness d, the maximum luminance is obtained when viewed from the normal direction. Furthermore, under all conditions of thickness d, a substantially symmetrical luminance distribution is obtained even when the viewing position is tilted to the left with respect to the normal direction, or even when the viewing position is tilted to the right with respect to the normal direction. In particular, it has been found that as the thickness d increases, the high luminance region tends to shrink (or is limited to a polar angle close to the normal). However, when the thickness d exceeds 55 μm, the luminance does not decrease sufficiently in the region where the polar angle exceeds 40°. Therefore, in order to limit the viewing angle to a narrow range, conditions for a preferred thickness d exist, and in the above example, the thickness d is preferably about 45 μm.

[0102] Fig. Figure 13 shows a graph showing the viewing angle behavior of the first viewing angle control panel 1 in the on state. The abscissa of the graph represents the polar angle (°) with respect to the normal of the display device, and the ordinate of the graph represents the luminance (relative value).

[0103] The simulation conditions are as described above. The voltage applied to the first liquid crystal layer LC1 is 30 V (switched on).

[0104] Under all conditions of thickness d, an equivalent viewing angle behavior is obtained in the switched-on state. Therefore, the viewing angle behaviors for all thicknesses in Fig. 13 overlapped. Furthermore, under all conditions of thickness d, a substantially symmetrical luminance distribution is obtained, even when the viewing position is tilted to the left with respect to the normal direction, or even when the viewing position is tilted to the right with respect to the normal direction. The area of ​​the high LED in the on state is larger than the area of ​​the high LED in the off state. <Zweites Ausbildungsbeispiel>

[0105] Fig. 14 is a view showing another configuration example of the display device DSP of the present embodiment.

[0106] The Fig. The second training example shown in Figure 14 differs from the one shown in Fig. 1 in that the display device DSP is further provided with a third viewing angle control field 3 and a sixth polarizing plate POL6.

[0107] The first viewing angle control field 1 is provided between the display panel PNL and the polarization axis rotating element 100. The second viewing angle control field 2 and the third viewing angle control field 3 are provided between the polarization axis rotating element 100 and the illumination device IL. In the illustrated embodiment, the third viewing angle control field 3 is provided between the second viewing angle control field 2 and the illumination device IL. The polarization axis rotating element 100 is provided between the first viewing angle control field 1 and the second viewing angle control field 2 or between the first viewing angle control field 1 and the third viewing angle control field 3.

[0108] The first polarizing plate POL1 is provided on the front side of the display panel PNL (or on the side of the viewing position at which the display device DSP is viewed). The second polarizing plate POL2 is provided between the display panel PNL and the first viewing angle control panel 1. The third polarizing plate POL3 is provided between the first viewing angle control panel 1 and the polarization axis rotating element 100. The fourth polarizing plate POL4 is provided between the polarization axis rotating element 100 and the second viewing angle control panel 2. The fifth polarizing plate POL5 is provided between the second viewing angle control panel 2 and the third viewing angle control panel 3. The sixth polarizing plate POL6 is provided on the back side of the third viewing angle control panel 3 (or between the third viewing angle control panel 3 and the illuminator IL).

[0109] The third viewing angle control panel 3 is a twisted nematic liquid crystal element, such as the one shown in Fig. 2 shown second view angle control field 2. As in Fig. 14, the third viewing angle control panel 3 is provided with a seventh substrate SUB7, an eighth substrate SUB8, and a third liquid crystal layer LC3.

[0110] The seventh substrate SUB7 is positioned on the front side of the eighth substrate SUB8. The seventh substrate SUB7 is provided with an insulating substrate 70, a fifth transparent electrode TE5, and an alignment film AL7. The fifth transparent electrode TE5 is provided between the insulating substrate 70 and the alignment film AL7.

[0111] The eighth substrate SUB8 is provided with an insulating substrate 80, a sixth transparent electrode TE6, and an alignment film AL8. The sixth transparent electrode TE6 is provided between the insulating substrate 80 and the alignment film AL8. The alignment film AL7 and the alignment film AL8 are in contact with the third liquid crystal layer LC3. These alignment films AL7 and AL8 are horizontally aligned films.

[0112] The third liquid crystal layer LC3 is held between the seventh substrate SUB7 and the eighth substrate SUB8 and sealed by a gasket. The third liquid crystal layer LC3 contains twisted liquid crystal molecules and has the optical rotation ability to rotate the polarization axis of the polarization component, which is linearly polarized light.

[0113] That is, the third viewing angle control panel 3 is a liquid crystal display formed in the same manner as the second viewing angle control panel 2, but the alignment state of the liquid crystal molecules in the third liquid crystal layer LC3 differs from that in the second liquid crystal layer LC2, as will be described later. The different alignment state of the liquid crystal molecules includes, for example,the case where, when the liquid crystal layer is viewed in plan view, the plurality of liquid crystal molecules lined up in the third direction Z are twistedly aligned in different rotation directions, the case where the initial azimuth of alignment of the liquid crystal molecules positioned close to the substrate interface in the liquid crystal layer is different, the case where the initial azimuth of alignment of the liquid crystal molecules positioned in the middle layer of the liquid crystal layers is different, the case where the pretilt angle of the liquid crystal molecules is different, or the case where the twist angle of the liquid crystal molecules is different.

[0114] Fig. Fig. 15 is a view showing the axial angle of each optical element which has the Fig. 14 shown display device DSP.

[0115] The respective transparency axes of the first polarizing plate POL1, the second polarizing plate POL2, the third polarizing plate POL3, the fourth polarizing plate POL4, and the fifth polarizing plate POL5 as well as the fast axis of the polarization axis rotating element 100 are the same as in the Fig. 3 training example shown.

[0116] The sixth polarization plate POL6 has a sixth transmission axis T6.

[0117] The respective transmission axes of the fifth polarization plate POL5 and the sixth polarization plate POL6, which clamp the third viewing angle control panel 3, are orthogonal to each other. This means that the fifth transmission axis T5 is positioned at an azimuth of 135°. The sixth transmission axis T6 is essentially orthogonal to the fifth transmission axis T5 and is positioned at an azimuth of 45°.

[0118] Next, the third viewing angle control field 3 is explained.

[0119] Fig. 16 is a view showing a configuration example of the third viewing angle control panel 3. Here, the initial alignment state of the liquid crystal molecules LM3 is in the off state when no voltage is applied to the liquid crystal layer LC3 between the alignment film AL8 and the alignment film AL7.

[0120] The alignment processing direction AD8 of the alignment film AL8 is substantially orthogonal to the alignment processing direction AD7 of the alignment film AL7. Fig. In the embodiment shown in Figure 16, the alignment processing direction AD8 is substantially orthogonal to the sixth transmission axis T6, and the alignment processing direction AD7 is substantially orthogonal to the fifth transmission axis T5. That is, the alignment processing direction AD8 is positioned at an azimuth of 135°, and the alignment processing direction AD7 is positioned at an azimuth of 225°.

[0121] In the third liquid crystal layer LC3, the liquid crystal molecules LM3, which are arranged along the third direction Z, are aligned in a twisted manner. Fig. 16 schematically shows the plurality of liquid crystal molecules LM3 in a plan view. A chiral agent is added to the third liquid crystal layer LC3, and the liquid crystal molecules LM3 are formed such that they are twisted counterclockwise from the sixth polarizing plate POL6 (or from the eighth substrate SUB8) to the fifth polarizing plate POL5 (or to the seventh substrate SUB7). That is, the liquid crystal molecules LM3 are twisted in a different direction than the liquid crystal molecules LM2 of the second liquid crystal layer LC2. Furthermore, the liquid crystal molecules LM2 of the second liquid crystal layer LC2 and the liquid crystal molecules LM3 of the third liquid crystal layer LC3 can also be twisted in the same direction. That is, the liquid crystal molecules LM2 and the liquid crystal molecules LM3 can each be twisted clockwise or counterclockwise.

[0122] The liquid crystal molecules LMF adjacent to the sixth polarization plate POL6 and the eighth substrate SUB8 are aligned such that their longitudinal axis runs along the alignment processing direction AD8. Alternatively, the liquid crystal molecules LMF may also be aligned substantially orthogonally to the sixth transmission axis T6. That is, the liquid crystal molecules LMF are aligned at an azimuth of 135°. The alignment azimuth of the liquid crystal molecules LMF is substantially parallel to the alignment azimuth of the liquid crystal molecules LMC in the Fig. 6 in the XY plane. Furthermore, the end of the liquid crystal molecules LMF on the tip side of the arrow indicating the alignment processing direction AD8 is tilted away from the eighth substrate SUB8.

[0123] The liquid crystal molecules LMG adjacent to the fifth polarizing plate POL5 and the seventh substrate SUB7 are aligned such that their longitudinal axes run along the alignment processing direction AD7. Alternatively, the liquid crystal molecules LMG may also be aligned substantially orthogonally to the fifth transmission axis T5. That is, the liquid crystal molecules LMG are aligned at an azimuth of 225°. Furthermore, the end of the liquid crystal molecules LMG on the tip side of the arrow indicating the alignment processing direction AD7 is tilted away from the seventh substrate SUB7 (or the end on the back side of the arrow indicating the processing direction AD7 is adjacent to the seventh substrate SUB7).

[0124] The liquid crystal molecules (third liquid crystal molecules) LMH in the substantially central (middle layer) in the third direction (thickness direction) Z of the third liquid crystal layer LC3 are aligned such that their longitudinal axis runs along the second direction Y. The longitudinal axis of the liquid crystal molecules LMH is substantially parallel to the first transmission axis T1 of the Fig. 14. This means that in the XY plane, the orientation azimuth of the liquid crystal molecules LME in the second liquid crystal layer LC2 differs from the orientation azimuth of the liquid crystal molecules LMF in the third liquid crystal layer LC3 and is, for example, orthogonal to it.

[0125] At least one of the arrows indicating the alignment processing direction AD7 and the arrow indicating the alignment processing direction AD8 may be oriented in opposite directions. Furthermore, the alignment processing direction AD8 may be positioned at an azimuth of 225°, and the alignment processing direction AD7 may be positioned at an azimuth of 135°. When the liquid crystal molecules LMH are aligned along the second direction Y, the liquid crystal molecules LM3 aligned along the third direction Z may be aligned in a counterclockwise twisted direction.

[0126] Such a third viewing angle control panel 3 is rotationally symmetric at 90° with respect to the above second viewing angle control panel 2 in the XY plane. Therefore, the viewing angle behavior of the third viewing angle control panel 3 is rotationally symmetric at 90° with respect to the viewing angle behavior of the second viewing angle control panel 2 in the XY plane. In the on-state in which a voltage is applied to the third liquid crystal layer LC3, the respective luminance distributions are asymmetric depending on the case where the viewing position on the upper side of the drawing (on the tip side of the arrow indicating the second Y direction) is inclined with respect to the normal direction (third Z direction) of the display device, and the case where the viewing position on the lower side of the drawing (on the back side of the arrow indicating the second Y direction) is inclined with respect to the normal direction.

[0127] In this way, in the present embodiment, the first viewing angle control panel 1, the second viewing angle control panel 2, and the third viewing angle control panel 3 are combined, whereby the viewing angle can be controlled not only in the lateral direction but also in the vertical direction. <Zweites Ausbildungsbeispiel; Abgewandeltes Beispiel>

[0128] In the modified example explained below, the display device DSP of the device described with reference to Fig. 14 and Fig. 15 explains the formation of the third viewing angle control field 3. The third viewing angle control field 3 in the modified example is explained below.

[0129] Fig. 17 is a view showing another embodiment of the third viewing angle control panel 3. Here, the initial alignment state of the liquid crystal molecules LM3 is in the off state when no voltage is applied to the liquid crystal layer LC3 between the alignment film AL8 and the alignment film AL7.

[0130] The alignment processing direction AD8 of the alignment film AL8 is substantially orthogonal to the alignment processing direction AD7 of the alignment film AL7. Fig. In the embodiment shown in Figure 17, the alignment processing direction AD8 is substantially parallel to the sixth transmission axis T6, and the alignment processing direction AD7 is substantially parallel to the fifth transmission axis T5. That is, the alignment processing direction AD8 is positioned at an azimuth of 45°, and the alignment processing direction AD7 is positioned at an angle of 135°.

[0131] In the third liquid crystal layer LC3, the liquid crystal molecules LM3, which are arranged along the third direction Z, are aligned in a twisted manner. Fig. 17 schematically illustrates the plurality of liquid crystal molecules LM3 in a plan view. A chiral agent is added to the third liquid crystal layer LC3, and the liquid crystal molecules LM3 are formed such that they are twisted counterclockwise from the sixth polarizing plate POL6 (or the eighth substrate SUB8) to the fifth polarizing plate POL5 (or the seventh substrate SUB7). That is, the alignment state of the liquid crystal molecules LC3 is different from the alignment state of the liquid crystal molecules LC2, and the liquid crystal molecules LM3 of the third liquid crystal layer LC3 are twisted in a different direction than the liquid crystal molecules LM2 of the second liquid crystal layer LC2.

[0132] The liquid crystal molecules LMF adjacent to the sixth polarization plate POL6 and the eighth substrate SUB8 are aligned such that their longitudinal axis runs along the alignment processing direction AD8. Alternatively, the liquid crystal molecules LMF are also aligned in an azimuth substantially parallel to the sixth transmission axis T6. That is, the liquid crystal molecules LMF are aligned in an azimuth of 45°. In addition, the alignment azimuth of the liquid crystal molecules LMF in the XY plane is substantially orthogonal to the alignment azimuth of the liquid crystal molecules LMC in the Fig. 6. Furthermore, the end of the liquid crystal molecules LMF on the tip side of the arrow indicating the alignment processing direction AD8 is tilted away from the eighth substrate SUB8.

[0133] The liquid crystal molecules LMG adjacent to the fifth polarizing plate POL5 and the seventh substrate SUB7 are aligned such that their longitudinal axis runs along the alignment processing direction AD7. Alternatively, the liquid crystal molecules LMG are aligned in an azimuth substantially parallel to the fifth transmission axis T5. That is, the liquid crystal molecules LMG are aligned at an angle of 135°. Furthermore, the alignment azimuth of the liquid crystal molecules LMG is substantially orthogonal in the XY plane to the alignment azimuth of the Fig. 6 are arranged in the second liquid crystal layer LC2. Furthermore, the end of the liquid crystal molecules LMG on the tip side of the arrow indicating the alignment processing direction AD7 is tilted away from the seventh substrate SUB7 (or the end on the back side of the arrow indicating the processing direction AD7 is adjacent to the seventh substrate SUB7).

[0134] The liquid crystal molecules (third liquid crystal molecules) LMH in the substantially central (middle layer) in the third direction (thickness direction) Z of the third liquid crystal layer LC3 are aligned such that their longitudinal axis runs along the first direction X. The longitudinal axis of the liquid crystal molecules LMH is substantially orthogonal to the first transmission axis T1 of the Fig. 14. That is, in the XY plane, the alignment azimuth of the liquid crystal molecules LME in the second liquid crystal layer LC2 is substantially parallel to the alignment azimuth of the liquid crystal molecules LMF in the third liquid crystal layer LC3.

[0135] At least one of the arrows indicating the alignment processing direction AD7 and the arrow indicating the alignment processing direction AD8 may be oriented in opposite directions. Furthermore, the alignment processing direction AD8 may be positioned at an azimuth of 135°, and the alignment processing direction AD7 may be positioned at an azimuth of 45°. When the liquid crystal molecules LMH are aligned along the first direction X, the liquid crystal molecules LM3 aligned along the third direction Z may be aligned in a counterclockwise twisted direction. <Drittes Ausbildungsbeispiel>

[0136] Fig. 18 shows a view of another embodiment of the display device DSP of the present invention.

[0137] The Fig. The third training example shown in Figure 18 differs from the one shown in Fig. 14 is different in that the third polarizing plate POL3 is omitted. That is, the first viewing angle control panel 1 faces the polarization axis rotating element 100. The polarization axis rotating element 100 is, for example, bonded to the insulating substrate 40 forming the first viewing angle control panel 1.

[0138] When the light passing through the polarization axis rotating element 100 is linearly polarized light having the same degree of polarization as the second polarization component incident on the first viewing angle control panel 1, the third polarizing plate POL3 may be omitted.

[0139] Therefore, in addition to the above effects, the number of components constituting the display device DSP can be reduced and the cost can be reduced. <vergleichsbeispiel>

[0140] Fig. 19 shows a comparative example of the display device DSP.

[0141] The Fig. The comparison example shown in Figure 19 differs from the one shown in Fig. 18 shown third embodiment in that the first viewing angle control field 1 is omitted. <Blickwinkelverhalten der Anzeigevorrichtung DSP>

[0142] Next, the viewing angle behavior of the DSP display device is explained.

[0143] Fig. Figure 20 shows the viewing angle behavior of the DSP display. The abscissa of the graph represents the polar angle (°) relative to the normal of the DSP display, and the ordinate of the graph represents the luminance (relative value).

[0144] The conditions of the simulation explained here are as follows. The configuration of the display device DSP assumed here is as explained in the modified example of the second embodiment example, in which the display panel PNL is sandwiched between the first polarizing plate POL1 and the second polarizing plate POL2, the first viewing angle control panel 1 is sandwiched between the second polarizing plate POL2 and the third polarizing plate POL3, the second viewing angle control panel 2 is sandwiched between the fourth polarizing plate POL4 and the fifth polarizing plate POL5, the third viewing angle control panel 3 is sandwiched between the fifth polarizing plate POL5 and the sixth polarizing plate POL6, and the polarization axis rotating element 100 is sandwiched between the third polarizing plate POL3 and the fourth polarizing plate POL4. The configuration of the second viewing angle control panel 2 is as described with reference to Fig. 6, and the formation of the third viewing angle control field 3 is as described with reference to Fig. 17 explained.

[0145] The illumination light from the illumination device IL is unpolarized, and the transmitted light wavelength is 550 nm. The anisotropy of the refractive index Δn in the first liquid crystal layer LC1 is 0.1482, and the first liquid crystal layer LC1 is made of a negative-type liquid crystal material. The applied voltage of the first liquid crystal layer LC1 is 0 V (off), and the applied voltage of the second liquid crystal layer LC2 is 2.5 V (on).

[0146] Here, the luminance versus polar angle was simulated for different thicknesses d of the first liquid crystal layer LC1. The thicknesses d were 1 µm, 1.5 µm, 2 µm, 2.5 µm, 3 µm, 3.5 µm, 4 µm, and 4.5 µm.

[0147] Under all conditions of thickness d, the maximum luminance is obtained when viewed from near the normal direction. Under all conditions of thickness d, due to the influences of the viewing angle behavior of the second viewing angle control panel 2 and the viewing angle control panel 3, an asymmetric luminance distribution is obtained depending on the case where the viewing position on the right side of the drawing is tilted with respect to the normal direction and the case where the viewing position on the left side of the drawing is tilted with respect to the normal direction. In the training example shown in the drawing, the luminance obtained when the viewing position is tilted to the right with respect to the normal direction is higher than the luminance obtained when the viewing position is tilted to the left with respect to the normal direction.

[0148] Fig. 21 shows the frontal ratio based on the Fig. The simulation results shown in Figure 20. The abscissa of the diagram shows the thickness d of the first liquid crystal layer LC1, and the ordinate of the figure shows the frontal ratio. The frontal ratio is defined here as the ratio of the luminance at a polar angle of 60° to the luminance at a polar angle of 0°.

[0149] From the results, it was found that when the thickness d is 1 µm or more, the frontal ratio in the direction of the polar angle of 60° is 12.5% ​​or less.

[0150] In this way, in the present embodiment, at least the first viewing angle control panel 1 and the second viewing angle control panel 2 are combined, whereby the viewing angle of the display device DSP can be controlled. <Vergleich von Blickwinkelverhalten>

[0151] Next, the above training and comparison examples are explained by comparing the respective viewing angle behaviors of the display device DSP.

[0152] Fig. Figure 22 shows the viewing angle behavior of the DSP display. The abscissa of the graph represents the polar angle (°) relative to the normal of the DSP display, and the ordinate of the graph represents the luminance (relative value).

[0153] The character C in the diagram shows the viewing angle behavior of the display device DSP in the comparative example, the character D in the diagram shows the viewing angle behavior of the display device DSP in the first embodiment example (the thickness d of the first liquid crystal layer LC1 is 1.5 µm), the character E in the diagram shows the viewing angle behavior of the display device DSP in the second embodiment example, and the character F in the diagram shows the viewing angle behavior of the display device DSP in the third embodiment example.

[0154] In each example, it was found that when the maximum luminance is 1, the luminance in the range of -20° or less (in the range of -20° to -80° in the diagram) of the polar angle is less than 10%, which is essentially a light-shielding state.

[0155] Furthermore, it was found that the viewing angle behaviors of the first, second, and third training examples can reduce the luminance compared to the viewing angle behavior of the comparative example even when the viewing position on the right side of the drawing is inclined with respect to the normal direction and even when the viewing position on the left side of the drawing is inclined with respect to the normal direction.

[0156] In particular, according to the second and third training examples, it was found that when the maximum luminance is 1, the luminance can be reduced to less than 10% in the range of 40° or more of the polar angle. <anwendungsbeispiel>

[0157] Fig. 23 shows an example application of the display device DSP. Fig. The display device DSP shown in Fig. 23 corresponds to a vehicle display device installed in a vehicle 200. The vehicle 200 is provided with: a windshield 210 provided at the front of the vehicle, side windows 211 and 212 provided at the sides of the vehicle 200, respectively, a driver's seat 221 and a passenger's seat 222, an instrument panel 230 provided in front of the driver's seat 221 and the passenger's seat 222, a display device DSP provided on the instrument panel 230, and side mirrors 241 and 242 provided at the sides of the vehicle 200, respectively.

[0158] The display device DSP is positioned in front of the driver's seat 221 and the passenger's seat 222. It is further assumed that the driver's seat 221 and the passenger's seat 222 are aligned in the first direction X explained in each of the above embodiment examples.

[0159] When the display device DSP is formed by applying each of the above forming examples, the azimuth on the tip side of the arrow indicating the first direction X in Fig. 3, the azimuth on the passenger side, and the azimuth on the back of the arrow, which indicates the first direction X, corresponds to the azimuth on the driver side. Fig. 22 etc., the range of positive pole angles corresponds to the pole angle when viewing the DSP display from the passenger side, and the range of negative pole angles corresponds to the pole angle when viewing the DSP display from the driver side.

[0160] Now, the driver in the driver's seat 221 views the DSP display device essentially from the front or from the left oblique direction. The passenger in the passenger seat 222 views the DSP display device essentially from the front or from the right oblique direction.

[0161] When the first angle control field 1 is set to the off state and the second angle control field 2 is set to the on state, the settings in Fig. 22 is maintained. Therefore, when the driver in the driver's seat 221 attempts to observe the display device DSP in a polar angle range of 20° or more (range from -20° to -80°), it essentially enters the light-shielding state. Consequently, the driver cannot see the image displayed on the display device DSP. The driver can see the image displayed on the display device DSP in the mode in which the second view angle control panel 2 is set to the off state.

[0162] On the other hand, when the passenger on the passenger seat 222 tries to observe the display device DSP in a polar angle range of 30° or less (range from 0° to 30°), he can see the image displayed on the display device DSP.

[0163] In a polar angle range above 40° (in the range of 40° to 80°), as described above, the luminance is reduced to less than 10%. Therefore, an undesirable phenomenon (reflection) of the displayed image being projected onto the side window 212 is suppressed. This can suppress a reduction in visibility when the driver sees the side mirror 242 through the side window 212.

[0164] In the above application example, an example in which the display device DSP is installed in a vehicle was explained, but it is not limited to this. The display device DSP according to the present embodiment can be used, for example, for electronic devices such as portable electronic devices and various monitors.

[0165] As explained above, according to the present embodiment, a display device capable of controlling the viewing angle can be provided.

[0166] This invention is not limited to the above-mentioned embodiments, but can be made more concrete by modifying the components to the extent that the implementation does not deviate from the gist of the invention. Various inventions can also be formed by appropriately combining the multiple components disclosed in the above-mentioned embodiments. For example, some of the components may be deleted from all of the components shown in the embodiments. Furthermore, components from different embodiments can be combined as needed.< / anwendungsbeispiel> < / vergleichsbeispiel>

Claims

[1] Display device provided with: a display panel that modulates a first polarization component, a first viewing angle control panel having a first liquid crystal layer containing hybrid aligned liquid crystal molecules, a second viewing angle control panel having a second liquid crystal layer containing twisted liquid crystal molecules, and a polarization axis rotating element provided between the first viewing angle control field and the second viewing angle control field, wherein the first viewing angle control panel is provided between the polarization axis rotating element and the display panel, in plan view, the initial alignment direction of the horizontally aligned first liquid crystal molecules among the liquid crystal molecules of the first liquid crystal layer is substantially orthogonal to the initial alignment direction of the second liquid crystal molecules positioned in a middle layer among the liquid crystal molecules of the second liquid crystal layer, a second polarization axis of a second polarization component penetrating the first viewing angle control panel is substantially parallel to a first polarization axis of the first polarization component, a third polarization axis of a third polarization component penetrating the second viewing angle control panel is different from the second polarization axis,and a polarization direction of light passing through the polarization axis rotating element is rotated from the third to the second polarization axis., [2] A display device according to claim 1, wherein the polarization axis rotating element is configured to impart a phase difference of half a wavelength to the third polarization component. [3] A display device according to claim 2, further comprising: a first polarizing plate provided on the front side of the display panel, a second polarizing plate provided between the display panel and the first viewing angle control panel, a third polarizing plate provided between the first viewing angle control panel and the polarization axis rotating element, a fourth polarizing plate provided between the polarization axis rotating element and the second viewing angle control panel, and a fifth polarizing plate provided on the back of the second viewing angle control panel, wherein the third polarization plate has a third transmission axis which allows the second polarization component to penetrate, the fourth polarization plate has a fourth transmission axis that allows the third polarization component to pass through, and in plan view, the fast axis and the slow axis of the polarization axis rotating element are positioned in an azimuth between the azimuth of the third transmission axis and the azimuth of the fourth transmission axis. [4] A display device according to claim 3, wherein the first polarizing plate has a first absorption axis, and in plan view, the initial alignment direction of the second liquid crystal molecules is substantially parallel to the first absorption axis. [5] A display device according to claim 3, further comprising a third viewing angle control panel including a third liquid crystal layer containing twisted aligned liquid crystal molecules, wherein the alignment state of the third liquid crystal layer is different from the alignment state of the second liquid crystal layer, and in plan view, the initial alignment direction of the third liquid crystal molecules positioned in the middle layer among the liquid crystal molecules of the third liquid crystal layer is substantially orthogonal to the initial alignment direction of the second liquid crystal molecules. [6] A display device according to claim 5, further comprising a sixth polarizing plate provided on the back side of the third viewing angle control panel, wherein the liquid crystal molecules are aligned in a twisted manner from the fifth polarizing plate to the fourth polarizing plate, and the liquid crystal molecules of the third liquid crystal layer are aligned in a twisted manner from the sixth polarizing plate to the fifth polarizing plate. [7] A display device according to claim 6, wherein, in plan view, the initial alignment direction of the liquid crystal molecules adjacent to the fifth polarizing plate among the liquid crystal molecules of the second liquid crystal layer is substantially parallel to the initial alignment direction of the liquid crystal molecules adjacent to the sixth polarizing plate among the liquid crystal molecules of the third liquid crystal layer. [8] A display device according to claim 7, wherein in the second liquid crystal layer, the liquid crystal molecules adjacent to the fifth polarizing plate are aligned at an azimuth of 135° counterclockwise with respect to the reference azimuth, the liquid crystal molecules adjacent to the fourth polarizing plate are aligned at an azimuth of 45° counterclockwise with respect to the reference azimuth, in the third liquid crystal layer, the liquid crystal molecules adjacent to the sixth polarizing plate are aligned at an azimuth of 135° counterclockwise with respect to the reference azimuth, and the liquid crystal molecules adjacent to the fifth polarizing plate are aligned at an azimuth of 225° counterclockwise with respect to the reference azimuth. [9] A display device according to claim 3, further comprising a third viewing angle control panel including a third liquid crystal layer containing twisted aligned liquid crystal molecules, wherein the alignment state of the third liquid crystal layer is different from the alignment state of the second liquid crystal layer, and in plan view, the initial alignment direction of the third liquid crystal molecules positioned in the middle layer among the liquid crystal molecules of the third liquid crystal layer is substantially parallel to the initial alignment direction of the second liquid crystal molecules. [10] A display device according to claim 9, further comprising a sixth polarizing plate provided on the back side of the third viewing angle control panel, wherein, in plan view, the initial alignment direction of the liquid crystal molecules adjacent to the fifth polarizing plate among the liquid crystal molecules of the second liquid crystal layer is substantially orthogonal to the initial alignment direction of the liquid crystal molecules adjacent to the sixth polarizing plate among the liquid crystal molecules of the third liquid crystal layer. [11] A display device according to claim 10, wherein in the second liquid crystal layer, the liquid crystal molecules adjacent to the fifth polarizing plate are aligned at an azimuth of 135° counterclockwise with respect to the reference azimuth, the liquid crystal molecules adjacent to the fourth polarizing plate are aligned at an azimuth of 45° counterclockwise with respect to the reference azimuth, in the third liquid crystal layer, the liquid crystal molecules adjacent to the sixth polarizing plate are aligned at an azimuth of 45° counterclockwise with respect to the reference azimuth, and the liquid crystal molecules adjacent to the fifth polarizing plate are aligned at an azimuth of 135° counterclockwise with respect to the reference azimuth.

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