Non-polarizing twist nematic filter for glasses-free 2d-3d switchable display

Abstract

The present invention relates to a filter for a display comprising: a lower substrate; a lower lens disposed on the lower substrate; a liquid crystal layer disposed on the lower lens and comprising a plurality of liquid crystal molecules; an upper lens disposed on the liquid crystal layer; and an upper substrate disposed on the upper lens, wherein the surfaces of the upper lens and the lower lens each comprise a stripe-shaped pattern, and the orientation of liquid crystal molecules within the liquid crystal layer is defined by an inclination angle (θ) and an azimuth angle (φ) with respect to the substrate, and in a state where no voltage is applied, the azimuth angle (φ) changes linearly from 0° to 90° in the thickness direction of the liquid crystal layer, so that the liquid crystal molecules within the liquid crystal layer form a 90° twist orientation structure in the vertical direction.

Description

Technology Field

[0001] The present invention relates to a display device, and more specifically, to a filter for a glasses-free display capable of switching between 2D mode and 3D mode without using a polarizer. Background Technology

[0002] Three-dimensional (3D) imaging technology is a technology that utilizes human binocular parallax to enable the perception of depth on flat displays. 3D displays are broadly classified into glasses-based and glasses-free types, and glasses-free 3D displays have recently been receiving a lot of attention for providing convenience to users.

[0003] However, displays that operate exclusively in 3D mode present a problem where image quality degrades when viewing 2D content. To address this, display technology capable of switching between 2D and 3D modes is being developed. This 2D-3D switching technology attaches a separate conversion filter to the top of the existing display; in 2D mode, it utilizes the display's original resolution, while in 3D mode, the conversion filter operates using a lenticular or barrier method to provide a sense of depth.

[0004] Lenticular lenses, a representative type among existing 2D-3D conversion filters, consist of a lens structure with an isotropic refractive index and a liquid crystal layer whose refractive index is controlled by the application of voltage. In this method, liquid crystal molecules are aligned parallel to the substrate when no voltage is applied, and align perpendicularly when voltage is applied, thereby controlling the path of light. However, in this structure, since the change in the liquid crystal's refractive index occurs along only one axis, a method is generally used in which a polarizer is attached to the bottom plate to ensure that only polarized light in a specific direction is incident. This results in a disadvantage where the amount of light decreases by more than 50%.

[0005] Furthermore, 3D image quality is significantly affected by the viewer's position. To address this, current 2D-3D conversion displays are linked with cameras to track the viewer's face and eye positions, and adjust the video and conversion filters accordingly to provide optimal 3D image quality. However, existing methods still suffer from the fundamental problem of reduced brightness caused by the use of polarizers.

[0006] Therefore, there is a need to develop a new type of filter for displays that enables effective switching between 2D and 3D modes without using a polarizer.

[0007] Korean registered patent No. 10-1651995, which is the background technology of the present invention, relates to a glasses-free 3D display device that does not require eye width adjustment. The problem to be solved

[0008] The present invention aims to solve the problems of the aforementioned conventional technology by providing a filter for a glasses-free 2D-3D switching display that can control the direction of light propagation without using a polarizer.

[0009] In addition, a 2D-3D switchable display with excellent image quality including the above-mentioned display filter is provided.

[0010] In addition, a television including the above display is provided.

[0011] In addition, a mobile device including the above display is provided.

[0012] In addition, medical imaging equipment including the above-mentioned display is provided.

[0013] However, the technical problems that the embodiments of the present invention aim to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0014] As a technical means for achieving the above-mentioned technical problem, the first aspect of the present invention provides a filter for a display comprising: a lower substrate; a lower lens disposed on the lower substrate; a liquid crystal layer disposed on the lower lens and comprising a plurality of liquid crystal molecules; an upper lens disposed on the liquid crystal layer; and an upper substrate disposed on the upper lens, wherein the surfaces of the upper lens and the lower lens each comprise a stripe-shaped pattern, and the orientation of liquid crystal molecules within the liquid crystal layer is defined by an inclination angle (θ) and an azimuth angle (φ) with respect to the substrate, and in a state where no voltage is applied, the azimuth angle (φ) changes linearly from 0° to 90° in the thickness direction of the liquid crystal layer, so that the liquid crystal molecules within the liquid crystal layer form a 90° twist orientation structure in the vertical direction.

[0015] According to one embodiment of the present invention, a lower electrode is disposed between the lower substrate and the lower lens, and an upper electrode is disposed between the upper substrate and the upper lens, and depending on whether voltage is applied to the lower electrode and the upper electrode, the orientation of liquid crystal molecules within the liquid crystal layer may change to cause a transition between a 2D mode and a 3D mode, but is not limited thereto.

[0016] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the liquid crystal molecules in the central part of the liquid crystal layer are oriented at an angle of inclination (θ) with respect to the substrate of 80° to 90°, and the liquid crystal molecules near the upper and lower boundary surfaces of the liquid crystal layer are maintained at an angle of inclination (θ) with respect to the substrate of 10° or less, and the change in the azimuth angle (φ) of the liquid crystal molecules is reduced so that the twist orientation structure is reduced, thereby allowing all polarization components of the incident light to be refracted and operate in a 3D mode, but is not limited thereto.

[0017] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the change in the azimuth angle (φ) may be 10° or less in an area within 3μm from the upper and lower boundary surfaces of the liquid crystal layer, respectively, but is not limited thereto.

[0018] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the inclination angle (θ) of the liquid crystal molecules in the liquid crystal layer may have a maximum value at the center of the liquid crystal layer and a distribution that decreases as it goes toward the upper and lower boundary surfaces, but is not limited thereto.

[0019] According to one embodiment of the present invention, when a voltage of more than 50V is applied, all liquid crystal molecules in the liquid crystal layer may be oriented perpendicular to the substrate so that all polarization components of the incident light pass through without refraction and operate in a 2D mode, but are not limited thereto.

[0020] According to one embodiment of the present invention, the lower lens and the upper lens may comprise an isotropic material having a refractive index of no, but are not limited thereto.

[0021] According to one embodiment of the present invention, the liquid crystal molecules in the liquid crystal layer may have a short axis refractive index no and a long axis refractive index ne, but are not limited thereto.

[0022] According to one embodiment of the present invention, the refractive index no of the isotropic material and the uniaxial refractive index no of the liquid crystal molecule may match, but are not limited thereto.

[0023] According to one embodiment of the present invention, the stripe-shaped patterns of the upper lens and the lower lens may be arranged so as to be parallel to each other and have their horizontal positions aligned, but are not limited thereto.

[0024] According to one embodiment of the present invention, the liquid crystal molecules in the liquid crystal layer may have a horizontal orientation on the lens surface or a horizontal orientation having a predetermined tilt angle, but are not limited thereto.

[0025] According to one embodiment of the present invention, an upper alignment layer may be disposed between the upper lens and the liquid crystal layer, and a lower alignment layer may be disposed between the lower lens and the liquid crystal layer, but is not limited thereto.

[0026] According to one embodiment of the present invention, the upper alignment layer and the lower alignment layer may be rubbed orthogonally to each other so that the liquid crystal molecules in the liquid crystal layer form a 90° twist orientation, but are not limited thereto.

[0027] According to one embodiment of the present invention, the rubbing direction of the lower alignment film may coincide with the direction of the stripe-shaped pattern of the lower lens, and the rubbing direction of the upper alignment film may be perpendicular to the stripe-shaped pattern of the upper lens, but is not limited thereto.

[0028] According to one embodiment of the present invention, a lower electrode may be disposed between the lower lens and the liquid crystal layer, and an upper electrode may be disposed between the upper lens and the liquid crystal layer, but is not limited thereto.

[0029] According to one embodiment of the present invention, a lower alignment layer may be disposed between the lower electrode and the liquid crystal layer, and an upper alignment layer may be disposed between the upper electrode and the liquid crystal layer, but is not limited thereto.

[0030] According to one embodiment of the present invention, the thickness of the liquid crystal layer may be 10 μm or more, but is not limited thereto.

[0031] According to one embodiment of the present invention, the upper lens and the lower lens are repeatedly arranged in the horizontal direction with a period of 100 μm or more and 400 μm or less, and the height from the lens valley to the lens apex may be 15 μm or more and 80 μm or less, but is not limited thereto.

[0032] According to one embodiment of the present invention, each of the upper lens and the lower lens may have a radius of curvature of R in the portion adjacent to the outside of the display filter and a radius of curvature of R or greater than infinity (∞) in the portion adjacent to the inside of the display filter, or a radius of curvature of R in the portion adjacent to the inside of the display filter and a radius of curvature of R or greater than infinity (∞) in the portion adjacent to the outside of the display filter, but is not limited thereto.

[0033] According to one embodiment of the present invention, the direction of the stripe-shaped pattern of the upper lens and the direction of the stripe-shaped pattern of the lower lens may be arranged to form an angle between 0° and 90°, but are not limited thereto.

[0034] Additionally, a second aspect of the present invention provides a display comprising a filter for a display according to the first aspect of the present invention.

[0035] Additionally, a third aspect of the present invention provides a 3D television comprising a display according to the second aspect of the present invention.

[0036] Additionally, the fourth aspect of the present invention provides a mobile device comprising a display according to the second aspect of the present invention.

[0037] Additionally, the fifth aspect of the present invention provides medical imaging equipment including a display according to the second aspect of the present invention.

[0038] The means for solving the problem described above are merely exemplary and should not be interpreted as intended to limit the present invention. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and the detailed description of the invention. Effects of the invention

[0039] The glasses-free twist nematic non-polarized 2D-3D switchable filter according to the present invention enables effective 2D-3D mode switching without using a polarizer. Accordingly, it is possible to provide brighter and clearer display quality by securing a light transmittance improved by approximately 2 times compared to conventional methods.

[0040] In addition, the display filter according to the present invention provides the ability to simultaneously control light of all polarization components by utilizing a twisted nematic liquid crystal alignment structure. Specifically, by changing the orientation of molecules within the liquid crystal layer in response to voltage application, all polarization components of incident light can be effectively refracted or straightened, thereby overcoming the limitations of the existing polarization-dependent method.

[0041] Furthermore, the filter according to the present invention can implement different operating modes depending on the voltage application level. Multi-mode switching is possible, operating in 3D mode when an intermediate voltage level (20V to 50V) is applied, and then back to 2D mode when a high voltage (over 50V) is applied. This characteristic significantly improves the flexibility of display utilization.

[0042] The display filter according to the present invention can provide a more natural 3D stereoscopic effect by forming a three-dimensional lens effect using different orientation characteristics of the region near the surface and the central region of the liquid crystal layer. In particular, the formation of a lens effect through the reduction of the change in azimuth angle near the liquid crystal layer boundary and the increase in the tilt angle in the central region can achieve superior 3D image quality compared to conventional methods.

[0043] The display filter according to the present invention can be applied to various display applications such as televisions, mobile devices, and medical imaging equipment, and can significantly contribute to the development of high-quality 3D imaging systems that require high brightness and clarity. Through this, it is expected that a more realistic 3D content experience can be provided in various fields such as entertainment, education, medical visualization, and advertising.

[0044] However, the effects obtainable from this invention are not limited to those described above, and other effects may exist. Brief explanation of the drawing

[0045] FIG. 1 is a cross-sectional view illustrating the operating principle of a 2D-3D conversion filter according to the prior art, where the left side shows a state where no voltage is applied and the right side shows a state where voltage is applied. FIG. 2 is a cross-sectional view showing the basic structure of a filter for a glasses-free, non-polarized 2D-3D switchable display according to one embodiment of the present invention. FIG. 3 is a cross-sectional view showing the liquid crystal molecule orientation state when an intermediate voltage (20V to 50V) is applied according to one embodiment of the present invention. FIG. 4 is a cross-sectional view showing the liquid crystal molecule orientation state when a high level voltage (greater than 50V) is applied according to one embodiment of the present invention. FIG. 5 is a cross-sectional view illustrating the principle of light refraction according to the polarization direction in a display filter according to one embodiment of the present invention. FIG. 6a is a diagram showing the definitions of Phi and Theta defining the orientation of liquid crystal molecules according to one embodiment of the present invention and the results of a liquid crystal distribution simulation according to the application of voltage. FIG. 6b is an enlarged view showing the changes in Phi and Theta and the approximate distribution of liquid crystal molecules near the surface of the liquid crystal layer according to one embodiment of the present invention. FIG. 7 is a drawing showing the overall cross-sectional structure and initial liquid crystal alignment state of a display filter according to one embodiment of the present invention. Specific details for implementing the invention

[0046] Embodiments of the present invention are described below with reference to the attached drawings to enable those skilled in the art to easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0047] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other elements interposed between them.

[0048] Throughout the entire specification, when a component is described as being located "on," "on top," "on top," "under," "on bottom," or "on bottom" of another component, this includes not only cases where the component is in contact with the other component but also cases where another component exists between the two components.

[0049] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0050] As used herein, terms of degree such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding the invention. Furthermore, throughout this specification, “a step of” or “a step of” does not mean “a step for”.

[0051] Throughout this specification, the term “combination thereof” included in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including one or more selected from the group consisting of said components.

[0052] Throughout the entire specification, the description "A and / or B" means "A, B, or A and B".

[0053] Hereinafter, a filter for a display and a display including the same according to the present invention will be described in detail with reference to embodiments, examples, and drawings. However, the present invention is not limited to these embodiments, examples, and drawings.

[0055] FIG. 1 is a cross-sectional view illustrating the operating principle of a 2D-3D conversion filter according to the prior art, with the left side showing a state where no voltage is applied and the right side showing a state where voltage is applied. The prior art display consists of a lens-shaped structure (10) and a liquid crystal layer (20), and the refractive index of the liquid crystal layer (20) is controlled by the application of voltage. As shown on the left side of FIG. 1, when no voltage is applied, the liquid crystal molecules are arranged parallel to the substrate, and as shown on the right side of FIG. 1, when voltage is applied, they are arranged vertically. In this method, since the change in the refractive index of the liquid crystal appears only along one axis, a polarizer must be used, which has the disadvantage of reducing the amount of light by 50%.

[0056] As a technical means for achieving the above-mentioned technical problem, the first aspect of the present invention comprises: a lower substrate (100); a lower lens (120) disposed on the lower substrate (100); a liquid crystal layer (140) disposed on the lower lens (120) and comprising a plurality of liquid crystal molecules; and an upper lens (160) disposed on the liquid crystal layer (140). A display filter is provided that includes an upper substrate (180) disposed on the upper lens (160), wherein the surfaces of the upper lens (160) and the lower lens (120) each include a stripe-shaped pattern, and the orientation of liquid crystal molecules within the liquid crystal layer (140) is defined by an inclination angle (θ) and an azimuth angle (φ) with respect to the substrate, and in a state where no voltage is applied, the azimuth angle (φ) changes linearly from 0° to 90° in the thickness direction of the liquid crystal layer (140) so that the liquid crystal molecules within the liquid crystal layer (140) form a 90° twist orientation structure in the vertical direction.

[0057] In order to implement a liquid crystal lens that does not use a polarizer in the present invention, a lens structure of a symmetrical shape is arranged on an upper lens (160) and a lower lens (120) as shown in FIG. 2. The display filter of the present invention has a stacked structure of a lower substrate (100), a lower lens (120), a liquid crystal layer (140), an upper lens (160), and an upper substrate (180). The surfaces of the lower lens (120) and the upper lens (160) are treated so that the liquid crystal is oriented horizontally, and through rubbing or an equivalent process, the liquid crystal is oriented at a certain angle of tilt. At this time, the rubbing direction can be set to be perpendicular to the upper and lower plates.

[0058] According to one embodiment of the present invention, a lower electrode (110) is disposed between the lower substrate (100) and the lower lens (120), and an upper electrode (170) is disposed between the upper substrate (180) and the upper lens (160). Depending on whether voltage is applied to the lower electrode (110) and the upper electrode (170), the orientation of liquid crystal molecules within the liquid crystal layer (140) may change, thereby causing a transition between a 2D mode and a 3D mode, but is not limited thereto.

[0059] Referring to FIG. 2, a lower electrode (110) and an upper electrode (170), a lower lens (120) and an upper lens (160), and an innermost liquid crystal layer (140) are respectively located between the lower substrate (100) and the upper substrate (180). By applying voltage to the lower electrode (110) and the upper electrode (170), the orientation of liquid crystal molecules within the liquid crystal layer (140) can be controlled, thereby enabling switching between 2D mode and 3D mode.

[0060] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the liquid crystal molecules in the central part of the liquid crystal layer (140) are oriented at an angle of inclination (θ) with respect to the substrate of 80° to 90°, and the liquid crystal molecules near the upper and lower boundary surface of the liquid crystal layer (140) are maintained at an angle of inclination (θ) with respect to the substrate of 10° or less, and the change in the azimuth angle (φ) of the liquid crystal molecules is reduced so that the twist orientation structure is reduced, thereby allowing all polarization components of the incident light to be refracted and operate in a 3D mode, but is not limited thereto.

[0061] FIG. 3 is a cross-sectional view showing the orientation state of liquid crystal molecules when an intermediate voltage (20V to 50V) is applied according to an embodiment of the present invention. In this state, liquid crystal molecules having positive dielectric anisotropy respond to the voltage and are oriented in a direction nearly perpendicular to the substrate (θ=80° to 90°) in the central part of the liquid crystal layer (140). On the other hand, near the upper and lower boundary surfaces, the tilt angle (θ) is maintained at 10° or less due to the influence of anchoring energy, and the change in the azimuth angle (φ) is also reduced. In this state, different refractive characteristics appear on the upper and lower sides of the liquid crystal layer, and all polarization components of the incident light are refracted and operate in a 3D mode.

[0062] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the inclination angle (θ) of the liquid crystal molecules in the liquid crystal layer (140) may have a maximum value at the center of the liquid crystal layer (140) and a distribution that decreases as it goes toward the upper and lower boundary surfaces, but is not limited thereto.

[0063] FIG. 6a is a diagram showing the definitions of Phi and Theta defining the orientation of liquid crystal molecules according to an embodiment of the present invention and the results of a simulation of liquid crystal distribution according to voltage application. The top-left figure of FIG. 6a shows the definitions of azimuth (φ) and tilt angle (θ), and the bottom-left figure shows the simulation model. As can be seen in the graph on the right, when voltage is applied (20V or more), the tilt angle (θ) of the liquid crystal molecules in the liquid crystal layer (140) has a maximum value of about 90° at the center and shows a distribution that decreases rapidly as it approaches the upper and lower boundary surfaces. This tilt angle distribution provides different refractive indices depending on the polarization state of the light, thereby causing a lens effect.

[0064] According to one embodiment of the present invention, when a voltage of 20V to 50V is applied, the change in the azimuth angle (φ) may be 10° or less in an area within 3μm from the upper and lower boundary surfaces of the liquid crystal layer (140), respectively, but is not limited thereto.

[0065] FIG. 6b is an enlarged view showing the change in Phi and Theta and the approximate distribution of liquid crystal molecules near the surface of a liquid crystal layer according to one embodiment of the present invention. When a voltage of 20V or higher is applied, the change in the azimuth angle (φ) is almost eliminated in the region within 3μm from the upper and lower boundary surfaces of the liquid crystal layer (140), respectively. As can be seen in the left graph of FIG. 6b, at a voltage of 20V or higher, it can be confirmed that the change in the Phi value within 3μm from the surface decreases to 10° or less. This means that the liquid crystal molecules are uniformly arranged along the surface orientation direction in that region.

[0066] According to one embodiment of the present invention, when a voltage greater than 50V is applied, all liquid crystal molecules within the liquid crystal layer (140) may be oriented perpendicular to the substrate so that all polarization components of the incident light pass through without refraction and operate in a 2D mode, but are not limited thereto.

[0067] FIG. 4 is a cross-sectional view showing the liquid crystal molecule orientation state when a high level voltage (greater than 50V) is applied according to an embodiment of the present invention. In this state, liquid crystal molecules are oriented in a direction almost perpendicular to the substrate in most areas of the liquid crystal layer (140). At this time, when light passes through, only the uniaxial refractive index (no) of the liquid crystal is felt, so the difference in refractive index between the lens layer and the liquid crystal layer disappears, and light passes through without refraction. Therefore, when a high voltage exceeding 50V is applied, it operates again in 2D mode.

[0068] According to one embodiment of the present invention, the lower lens (120) and the upper lens (160) may comprise an isotropic material with a refractive index of no, but are not limited thereto.

[0069] The lower lens (120) and the upper lens (160) are generally composed of an optically isotropic material and have the same refractive index (no) in all directions. This isotropic material serves to keep the lens effect constant and predictable.

[0070] According to one embodiment of the present invention, the liquid crystal molecules in the liquid crystal layer (140) may have a short axis refractive index no and a long axis refractive index ne, but are not limited thereto.

[0071] The liquid crystal molecules in the liquid crystal layer (140) have optical anisotropy, and the refractive index (ne) in the direction of the long axis of the molecule and the refractive index (no) in the direction of the short axis of the molecule are different from each other. This optical anisotropy allows the path of light to be effectively controlled through the change in orientation of the liquid crystal molecules according to the application of voltage.

[0072] According to one embodiment of the present invention, the refractive index no of the isotropic material and the uniaxial refractive index no of the liquid crystal molecule may match, but are not limited thereto.

[0073] FIG. 5 is a cross-sectional view illustrating the principle of light refraction according to the polarization direction in a display filter according to an embodiment of the present invention. By designing the isotropic material refractive index (no) of the lens structure (120, 160) to match the uniaxial refractive index (no) of the liquid crystal molecules, it is possible to prevent refraction from occurring at the interface between the lens and the liquid crystal layer when a high voltage exceeding 50V is applied. When a voltage exceeding 50V is applied, the liquid crystal molecules are oriented perpendicularly to the substrate, and in both of these states, the incident light experiences only the uniaxial refractive index (no) when passing through the liquid crystal layer (140). Therefore, the difference in refractive index between the lens structure and the liquid crystal layer is eliminated, so all polarization components of the incident light travel in a straight line without refraction and operate in 2D mode.

[0074] Meanwhile, when a voltage of 20V to 50V is applied, different refractive effects occur depending on the polarization direction. As shown in Fig. 5, when polarization perpendicular to the lens stripe direction is denoted as Polarization 1 and polarization perpendicular thereto is denoted as Polarization 2, in the case of Polarization 1, no change in refraction occurs at the lower boundary, but a refractive effect occurs at the upper boundary as it experiences the ne refractive index of the liquid crystal. On the other hand, Polarization 2 experiences the ne refractive index of the liquid crystal first at the lower boundary, causing refraction at the lower side, while passing through the upper side without any significant change in refraction. In this way, a lens effect occurs in both polarizations, making 3D implementation possible. That is, since all light is refracted regardless of polarization, effective 3D mode implementation is possible without a polarizer.

[0075] According to one embodiment of the present invention, the stripe-shaped patterns of the upper lens (160) and the lower lens (120) may be arranged so as to be parallel to each other and have their horizontal positions aligned, but are not limited thereto.

[0076] The stripe-shaped patterns of the upper lens (160) and the lower lens (120) are generally aligned parallel to each other and positioned so that their horizontal positions match. This arrangement is intended to accurately convey different images to the left and right eyes in 3D mode and plays an important role in effectively realizing a sense of depth.

[0077] According to one embodiment of the present invention, the liquid crystal molecules in the liquid crystal layer (140) may have a horizontal orientation on the lens surface or a horizontal orientation having a predetermined tilt angle, but are not limited thereto.

[0078] The liquid crystal molecules within the liquid crystal layer (140) are oriented horizontally on the lens surface in an initial state or have a horizontal orientation with a predetermined tilt angle. This initial orientation is essential for forming a twisted nematic structure and is an important factor in determining the movement of the liquid crystal molecules and the final orientation state when voltage is applied.

[0079] According to one embodiment of the present invention, an upper alignment layer may be disposed between the upper lens (160) and the liquid crystal layer (140), and a lower alignment layer may be disposed between the lower lens (120) and the liquid crystal layer (140), but is not limited thereto.

[0080] In one embodiment of the present invention, an upper alignment layer may be disposed between the upper lens (160) and the liquid crystal layer (140), and a lower alignment layer may be disposed between the lower lens (120) and the liquid crystal layer (140). These alignment layers may be composed of a polyimide-based horizontal alignment layer or a material capable of photo-alignment, and serve to determine the initial alignment direction of liquid crystal molecules.

[0081] According to one embodiment of the present invention, the upper alignment layer and the lower alignment layer may be rubbed orthogonally to each other so that the liquid crystal molecules in the liquid crystal layer (140) form a 90° twist alignment, but are not limited thereto.

[0082] The upper alignment layer and the lower alignment layer determine the orientation direction of the liquid crystal molecules through rubbing treatment. By rubbing the two alignment layers orthogonally (90°) to each other, the liquid crystal molecules within the liquid crystal layer (140) form a 90° twisted alignment structure between the substrates. This twisted structure is the core principle of the present invention and enables the control of the light path without a polarizer.

[0083] According to one embodiment of the present invention, the rubbing direction of the lower alignment film may coincide with the direction of the stripe-shaped pattern of the lower lens (120), and the rubbing direction of the upper alignment film may be perpendicular to the stripe-shaped pattern of the upper lens (160), but is not limited thereto.

[0084] The right side of FIG. 7 shows the initial liquid crystal alignment state, in which liquid crystal molecules near the surface of the lower lens (120) are oriented in a direction consistent with the stripe direction of the lens, and liquid crystal molecules near the surface of the upper lens (160) are oriented in a direction perpendicular to this. As a result, a 90° twist alignment structure is formed within the liquid crystal layer (140).

[0085] According to one embodiment of the present invention, a lower electrode may be disposed between the lower lens (120) and the liquid crystal layer (140), and an upper electrode may be disposed between the upper lens (160) and the liquid crystal layer (140), but is not limited thereto.

[0086] In another embodiment of the present invention, a lower electrode may be positioned between the lower lens (120) and the liquid crystal layer (140), and an upper electrode may be positioned between the upper lens (160) and the liquid crystal layer (140). This structure enables the formation of a more direct electric field between the electrodes and the liquid crystal layer, thereby allowing for more efficient control of the orientation change of liquid crystal molecules.

[0087] According to one embodiment of the present invention, a lower alignment layer may be disposed between the lower electrode and the liquid crystal layer (140), and an upper alignment layer may be disposed between the upper electrode and the liquid crystal layer (140), but is not limited thereto.

[0088] A lower alignment layer may be disposed between the lower electrode and the liquid crystal layer (140), and an upper alignment layer may be disposed between the upper electrode and the liquid crystal layer (140). In this structure, the alignment layer is positioned between the electrode and the liquid crystal layer to control the orientation of liquid crystal molecules while allowing the influence of the electric field to be directly transmitted to the liquid crystal layer.

[0089] According to one embodiment of the present invention, the thickness of the liquid crystal layer (140) may be 10 μm or more, but is not limited thereto.

[0090] The thickness of the liquid crystal layer (140) is generally designed to be 10 μm or more. This is to ensure that a sufficient twist orientation structure is formed within the liquid crystal layer and that a distinct difference in orientation between the liquid crystal molecules in the center and near the interface is observed when voltage is applied. The simulation in FIG. 6a shows the results when the cell gap is set to approximately 30 μm.

[0091] According to one embodiment of the present invention, the upper lens (160) and the lower lens (120) may be repeatedly arranged in the horizontal direction with a period of 100 μm or more and 400 μm or less, and the height from the lens valley to the lens apex may be 15 μm or more and 80 μm or less, but is not limited thereto.

[0092] The upper lens (160) and the lower lens (120) are designed to have specific sizes and periods to obtain an effective 3D effect. Generally, they are arranged repeatedly with periods between 100 μm and 400 μm, and the depth of the lens (height from the valley to the apex) is designed to be between 15 μm and 80 μm. These dimensions are optimized by taking into account the size and resolution of the display and the viewing distance.

[0093] According to one embodiment of the present invention, each of the upper lens (160) and the lower lens (120) may have a radius of curvature of R in the portion adjacent to the outside of the display filter and a radius of curvature of R or greater than infinity (∞) in the portion adjacent to the inside of the display filter, or a radius of curvature of R in the portion adjacent to the inside of the display filter and a radius of curvature of R or greater than infinity (∞) in the portion adjacent to the outside of the display filter, but is not limited thereto.

[0094] The design of the lens curvature is an important factor in optimizing the light refraction effect. In the present invention, a more effective lens effect can be obtained through the asymmetric curvature of the lens. The upper lens (160) and the lower lens (120) may be designed with different radii of curvature at the parts adjacent to the outside or inside of the display filter. This asymmetric curvature design allows for more precise control of the direction and angle of light refraction.

[0095] According to one embodiment of the present invention, the direction of the stripe-shaped pattern of the upper lens and the direction of the stripe-shaped pattern of the lower lens may be arranged to form an angle between 0° and 90°, but are not limited thereto.

[0096] The stripe pattern directions of the upper lens (160) and the lower lens (120) are generally arranged parallel to each other, but may be arranged at an angle between 0° and 90° for specific applications or to enhance 3D effects. This non-parallel arrangement can create more complex optical effects and, in particular, improve the stability of 3D effects depending on the viewing angle.

[0097] Additionally, a second aspect of the present invention provides a display comprising a filter for a display according to the first aspect of the present invention.

[0098] Regarding the display according to the second aspect of the present invention, detailed descriptions of parts that overlap with the first aspect of the present invention have been omitted, but even if such descriptions are omitted, the contents described in the first aspect of the present invention may be applied equally to the second aspect of the present invention.

[0099] A second aspect of the present invention is a display device comprising the filter for a glasses-free twist nematic non-polarized 2D-3D switchable display described above. This display device implements a 2D-3D switching function by attaching the filter of the present invention onto a conventional 2D display panel. Depending on whether voltage is applied, this display can provide both high-quality 2D and 3D images without a polarizer.

[0100] Additionally, a third aspect of the present invention provides a television comprising a display according to the second aspect of the present invention.

[0101] Regarding the television according to the third aspect of the present invention, detailed descriptions of parts that overlap with the second aspect of the present invention have been omitted, but even if such descriptions have been omitted, the contents described in the second aspect of the present invention may be applied equally to the third aspect of the present invention.

[0102] A third aspect of the present invention is a television comprising the previously described 2D-3D switchable display. This television allows a viewer to selectively switch between 2D mode and 3D mode as needed for viewing, and can provide clearer 3D images with brightness improved by approximately two times compared to conventional polarized 3D TVs.

[0103] Additionally, the fourth aspect of the present invention provides a mobile device comprising a display according to the second aspect of the present invention.

[0104] Regarding the mobile device according to the fourth aspect of the present invention, detailed descriptions of parts that overlap with the second aspect of the present invention have been omitted, but even if such descriptions are omitted, the contents described in the second aspect of the present invention may be applied equally to the fourth aspect of the present invention.

[0105] A fourth aspect of the present invention is a mobile device comprising the previously described 2D-3D switchable display. It is applied to mobile devices such as smartphones, tablets, and laptops, allowing users to selectively view content such as games, movies, and photos in 2D or 3D. In particular, battery life is important in mobile environments, and the high light transmittance of the present invention can achieve the same brightness with less power, thus offering advantages in terms of energy efficiency.

[0106] Additionally, the fifth aspect of the present invention provides medical imaging equipment comprising a display according to the second aspect of the present invention.

[0107] Regarding the medical imaging equipment according to the fifth aspect of the present invention, detailed descriptions of parts that overlap with the second aspect of the present invention have been omitted, but even if such descriptions are omitted, the contents described in the second aspect of the present invention may be applied equally to the fifth aspect of the present invention.

[0108] A fifth aspect of the present invention is a medical imaging device comprising the previously described 2D-3D switchable display. In the medical field, the ability to view diagnostic images such as CT, MRI, and ultrasound in 3D plays an important role in improving diagnostic accuracy. The high brightness and clarity of the present invention, along with the ability to freely switch between 2D and 3D, are particularly useful for medical image analysis.

[0109] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0110] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0111] 10: Lens-shaped structure (prior art) 20 : Liquid crystal layer (conventional technology) 100 : Lower substrate 110 : Lower electrode 120 : Lower lens 140 : Liquid crystal layer 160 : Upper lens 170 : Upper electrode 180 : Upper substrate

Claims

Claim 1 A lower substrate; a lower lens disposed on the lower substrate; a liquid crystal layer disposed on the lower lens and comprising a plurality of liquid crystal molecules; an upper lens disposed on the liquid crystal layer; and an upper substrate disposed on the upper lens; wherein the surfaces of the upper lens and the lower lens each include a stripe-shaped pattern, an upper alignment layer is disposed between the upper lens and the liquid crystal layer, and a lower alignment layer is disposed between the lower lens and the liquid crystal layer, wherein the orientation of liquid crystal molecules within the liquid crystal layer is defined by an inclination angle (θ) and an azimuth angle (φ) with respect to the substrate, wherein in a state where no voltage is applied, the azimuth angle (φ) changes linearly from 0° to 90° in the thickness direction of the liquid crystal layer so that the liquid crystal molecules within the liquid crystal layer form a 90° twist alignment structure in the vertical direction, wherein the stripe-shaped patterns of the upper lens and the lower lens are disposed so as to be parallel to each other and have corresponding horizontal positions, wherein the upper alignment layer and the lower alignment layer are rubbed orthogonally to each other to form the 90° twist alignment structure, and the rubbing direction of the lower alignment layer is the direction of the stripe-shaped pattern of the lower lens and The upper alignment layer is aligned, and the rubbing direction of the upper alignment layer is perpendicular to the stripe-shaped pattern of the upper lens; a lower electrode is disposed between the lower substrate and the lower lens, and an upper electrode is disposed between the upper substrate and the upper lens; depending on whether voltage is applied to the lower electrode and the upper electrode, the orientation of liquid crystal molecules within the liquid crystal layer changes, thereby causing a transition between 2D mode and 3D mode; under a voltage application state of 20V to 50V, the liquid crystal molecules in the central part of the liquid crystal layer are oriented with an inclination angle (θ) relative to the substrate of 80° to 90°, and the liquid crystal molecules near the upper and lower boundary surfaces of the liquid crystal layer maintain an inclination angle (θ) relative to the substrate of 10° or less, and the change in the azimuth angle (φ) of the liquid crystal molecules is reduced, thereby maintaining a state in which the twist alignment structure is reduced,A filter for a display, wherein all polarization components of incident light are refracted to operate in 3D mode, and when a voltage of 20V to 50V is applied, the change in the azimuth angle (φ) is 10° or less in the region within 3μm from each of the upper and lower boundary surfaces of the liquid crystal layer, and when a voltage of 20V to 50V is applied, the inclination angle (θ) of the liquid crystal molecules within the liquid crystal layer has a maximum value at the center of the liquid crystal layer and has a distribution that decreases as it goes toward the upper and lower boundary surfaces, and when a voltage of more than 50V is applied, all liquid crystal molecules within the liquid crystal layer are oriented perpendicular to the substrate so that all polarization components of incident light pass through without refraction to operate in 2D mode, wherein the lower lens and the upper lens comprise an isotropic material having a refractive index no, and the liquid crystal molecules within the liquid crystal layer have a uniaxial refractive index no and a major refractive index ne, and the refractive index no of the isotropic material matches the uniaxial refractive index no of the liquid crystal molecules. Claim 2 A lower substrate; a lower lens disposed on the lower substrate; a liquid crystal layer disposed on the lower lens and comprising a plurality of liquid crystal molecules; an upper lens disposed on the liquid crystal layer; and an upper substrate disposed on the upper lens; wherein the surfaces of the upper lens and the lower lens each include a stripe-shaped pattern, a lower electrode is disposed between the lower lens and the liquid crystal layer, an upper electrode is disposed between the upper lens and the liquid crystal layer, a lower alignment layer is disposed between the lower electrode and the liquid crystal layer, and an upper alignment layer is disposed between the upper electrode and the liquid crystal layer, wherein the orientation of liquid crystal molecules within the liquid crystal layer is defined by an inclination angle (θ) and an azimuth angle (φ) with respect to the substrate, wherein in a state where voltage is not applied, the azimuth angle (φ) changes linearly from 0° to 90° in the thickness direction of the liquid crystal layer so that the liquid crystal molecules within the liquid crystal layer form a 90° twist alignment structure in the vertical direction, wherein the stripe-shaped patterns of the upper lens and the lower lens are disposed such that they are parallel to each other and their horizontal positions coincide, and the upper alignment layer and the lower alignment layer are rubbed orthogonally to each other, and A 90° twist orientation structure is formed, wherein the rubbing direction of the lower alignment layer coincides with the direction of the stripe-shaped pattern of the lower lens, and the rubbing direction of the upper alignment layer is perpendicular to the stripe-shaped pattern of the upper lens, wherein the orientation of liquid crystal molecules within the liquid crystal layer changes depending on whether voltage is applied to the lower electrode and the upper electrode, thereby causing a transition between 2D mode and 3D mode, wherein under a voltage application state of 20V to 50V, the liquid crystal molecules in the central part of the liquid crystal layer are oriented with an inclination angle (θ) relative to the substrate of 80° to 90°, and the liquid crystal molecules near the upper and lower boundary surfaces of the liquid crystal layer maintain an inclination angle (θ) relative to the substrate of 10° or less, and thereby maintain a state in which the twist orientation structure is reduced by reducing the change in the azimuth angle (φ) of the liquid crystal molecules,A filter for a display, wherein all polarization components of incident light are refracted to operate in 3D mode, and when a voltage of 20V to 50V is applied, the change in the azimuth angle (φ) is 10° or less in the region within 3μm from each of the upper and lower boundary surfaces of the liquid crystal layer, and when a voltage of 20V to 50V is applied, the inclination angle (θ) of the liquid crystal molecules within the liquid crystal layer has a maximum value at the center of the liquid crystal layer and has a distribution that decreases as it goes toward the upper and lower boundary surfaces, and when a voltage of more than 50V is applied, all liquid crystal molecules within the liquid crystal layer are oriented perpendicular to the substrate so that all polarization components of incident light pass through without refraction to operate in 2D mode, wherein the lower lens and the upper lens comprise an isotropic material having a refractive index no, and the liquid crystal molecules within the liquid crystal layer have a uniaxial refractive index no and a major refractive index ne, and the refractive index no of the isotropic material matches the uniaxial refractive index no of the liquid crystal molecules. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 A display filter according to claim 1 or 2, wherein the liquid crystal molecules within the liquid crystal layer have a horizontal orientation on the lens surface or a horizontal orientation having a predetermined tilt angle. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 A filter for a display according to claim 1 or 2, wherein the thickness of the liquid crystal layer is 10 μm or more. Claim 18 A filter for a display according to claim 1 or 2, wherein the upper lens and the lower lens are repeatedly arranged in the horizontal direction with a period of 100 μm or more and 400 μm or less, and the height from the lens valley to the lens apex is 15 μm or more and 80 μm or less. Claim 19 A display filter according to claim 1 or 2, wherein each of the upper lens and the lower lens has a radius of curvature R at the portion adjacent to the outside of the display filter and a radius of curvature R greater than or equal to infinity (∞) at the portion adjacent to the inside of the display filter, or a radius of curvature R at the portion adjacent to the inside of the display filter and a radius of curvature R greater than or equal to infinity (∞) at the portion adjacent to the outside of the display filter. Claim 20 delete Claim 21 A display comprising a filter for a display according to claim 1 or 2. Claim 22 A television comprising a display according to claim 21. Claim 23 A mobile device comprising a display according to claim 21. Claim 24 Medical imaging equipment comprising a display according to claim 21.

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