Lens assembly and display device

Abstract

The invention relates to a lens assembly and a display device. The lens assembly includes an incident side on which light is incident and an exit side opposite to the incident side, the lens assembly including: a first polarization layer disposed adjacent to the incident side; a second polarization layer provided between the first polarization layer and the exit side; and the phase delay layer is arranged between the first polarization layer and the second polarization layer. The phase retardation layer has a first phase retardation refractive index along a first direction, a second phase retardation refractive index along a second direction equal to the first phase retardation refractive index, and a third phase retardation refractive index along a third direction perpendicular to the first direction and the second direction, and the first phase delay refractive index and the second phase delay refractive index are different from the third phase delay refractive index.

Description

Technical Field

[0001] The present disclosure relates to a lens assembly and a display device including the lens assembly. Background Art

[0002] As information technology has developed, the importance of display devices as a connection medium between users and information has emerged. Therefore, the use of display devices such as liquid crystal display devices and organic light emitting display devices has increased.

[0003] Recently, as one type of display device, a head mounted display (HMD) has been developed. A head mounted display is a display device that is mounted on a user's head and provides an image, and is currently available on the market and widely used in various fields including the entertainment industry.

[0004] For example, head mounted displays may be used for various applications such as virtual reality (VR) and augmented reality (AR).

[0005] Recently, research has been conducted on methods for improving the display quality of head-mounted displays. For example, research is being conducted on methods for reducing ghost images to provide users with virtual reality and augmented reality that are closer to reality. Summary of the invention

[0006] Embodiments of the present disclosure provide a lens assembly that can improve display quality and a display device including the lens assembly.

[0007] An embodiment of the present disclosure provides a lens assembly, including an incident side where light is incident and an exit side opposite to the incident side, wherein the lens assembly includes: a first polarization layer, arranged adjacent to the incident side; a second polarization layer, arranged between the first polarization layer and the exit side; a phase retardation layer, arranged between the first polarization layer and the second polarization layer; a first quarter wave plate, arranged between the second polarization layer and the exit side; a partial reflector layer, arranged between the first quarter wave plate and the exit side; a second quarter wave plate, arranged between the partial reflector layer and the exit side; and a third polarization layer, arranged adjacent to the exit side. In such an embodiment, the phase retardation layer has a first phase retardation refractive index along a first direction, has a second phase retardation refractive index equal to the first phase retardation refractive index along a second direction, and has a third phase retardation refractive index along a third direction perpendicular to the first direction and the second direction, and the first phase retardation refractive index and the second phase retardation refractive index are different from the third phase retardation refractive index.

[0008] In an embodiment, the phase retardation layer may include a material having a refractive index anisotropy.

[0009] In an embodiment, the phase retardation layer may have a phase retardation value (R ) in the range of about 500 nm to about 1500 nm with respect to visible light. th In such an embodiment, the phase retardation value (R th ) satisfies the following equation: R th ={(N X +N Y ) / 2-N Z}×d, where N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

[0010] In an embodiment, the material having refractive index anisotropy may include a discotic material or a liquid crystal material.

[0011] In an embodiment, the first to third phase-retarding refractive indices may be in a range of about 1.5 to about 1.9.

[0012] In an embodiment, the phase retardation layer may change a polarization state of light incident in a direction different from the third direction, and the first direction and the second direction may be the same as a direction in which a plane in which the phase retardation layer is disposed extends.

[0013] In an embodiment, a light transmission axis of the first polarizing layer and a light transmission axis of the second polarizing layer may be parallel to each other.

[0014] In an embodiment, the first polarizing layer may be a linear polarizing layer.

[0015] In an embodiment, the first polarizing layer may be in a film shape.

[0016] In an embodiment, the first polarization layer and the phase retardation layer may be spaced apart from each other.

[0017] In an embodiment, a material having isotropic refractive index may be disposed between the first polarization layer and the phase retardation layer.

[0018] In an embodiment, the lens assembly may further include an adhesive layer disposed between the first polarizing layer and the phase retardation layer, wherein the phase retardation layer may be coupled to the first polarizing layer through the adhesive layer.

[0019] In an embodiment, the phase retardation layer and the first polarization layer may contact each other.

[0020] In an embodiment, the phase retardation layer may be a layer formed on the first polarizing layer by a coating or deposition process.

[0021] Another embodiment of the present disclosure provides a display device, the display device comprising: a display panel, comprising a base layer disposed on a plane defined based on a first direction and a second direction different from the first direction, and a light-emitting element disposed on the base layer; and a lens assembly disposed on the display panel, wherein the lens assembly transmits light provided from the display panel, and the lens assembly comprises an incident side adjacent to the display panel and an exit side opposite to the incident side. In such an embodiment, the lens assembly comprises: a first polarizing layer disposed adjacent to the incident side; a second polarizing layer disposed between the first polarizing layer and the exit side; a phase delay layer disposed between the first polarizing layer and the second polarizing layer; a first quarter wave plate disposed between the second polarizing layer and the exit side; a partial reflector layer disposed between the first quarter wave plate and the exit side; a second quarter wave plate disposed between the partial reflector layer and the exit side; and a third polarizing layer disposed adjacent to the exit side. In such an embodiment, the phase retardation layer has a first phase retardation refractive index along the first direction, a second phase retardation refractive index along the second direction that is equal to the first phase retardation refractive index, and a third phase retardation refractive index along a third direction perpendicular to the first direction and the second direction, and the first phase retardation refractive index and the second phase retardation refractive index are different from the third phase retardation refractive index.

[0022] In an embodiment, the phase retardation layer may have a phase retardation value (R ) in the range of about 500 nm to about 1500 nm with respect to visible light. th In such an embodiment, the phase retardation value (R th ) satisfies the following equation: R th ={(N X +N Y ) / 2-N Z}×d, where N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

[0023] In an embodiment, the phase retardation layer may include a material having a refractive index anisotropy, and the phase retardation layer changes a polarization state of light incident in a direction different from the third direction.

[0024] In an embodiment, a light transmission axis of the first polarizing layer, a light transmission axis of the second polarizing layer, and a light transmission axis of the third polarizing layer may be parallel to each other.

[0025] Another embodiment of the present disclosure provides a lens assembly, which is configured to guide light and includes an incident side where the light is incident and an exit side opposite to the incident side, and the lens assembly includes: a first polarization layer, which is arranged adjacent to the incident side; a second polarization layer, which is arranged between the first polarization layer and the exit side; and a phase delay layer, which is arranged between the first polarization layer and the second polarization layer. In such an embodiment, the phase delay layer has a first phase delay refractive index along a first direction, a second phase delay refractive index along a second direction that is equal to the first phase delay refractive index, and a third phase delay refractive index along a third direction perpendicular to the first direction and the second direction, and the first phase delay refractive index and the second phase delay refractive index are different from the third phase delay refractive index.

[0026] In an embodiment, the phase retardation layer may have a phase retardation value (R ) in the range of about 500 nm to about 1500 nm with respect to visible light. th In such an embodiment, the phase retardation value (R th ) satisfies the following equation: R th ={(N X +N Y ) / 2-N Z}×d, where N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

[0027] According to the embodiments of the present disclosure, a lens assembly that can improve display quality and a display device including the lens assembly can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A display device according to an embodiment is schematically shown.

[0029] Figure 2 A schematic top plan view of a display panel according to an embodiment is shown.

[0030] Figure 3 A schematic cross-sectional view of a lens assembly according to an embodiment is shown.

[0031] Figure 4The light paths of the side light and the front light emitted from the display panel are schematically shown.

[0032] FIG. 5A to FIG. 5F The TECH WIZ 1D simulation results of the outgoing light according to the presence or absence of the phase retardation layer and the phase retardation value of the phase retardation layer are shown.

[0033] Figure 6 The path of the light path being folded is schematically shown.

[0034] Figure 7 A schematic cross-sectional view of a lens assembly according to another embodiment is shown.

[0035] Figure 8 A schematic cross-sectional view of a lens assembly according to another embodiment is shown.

[0036] Fig. 9 and Fig.10 The schematic diagram shows the application Figure 1 An embodiment of an electronic device of a display device.

[0037] Fig.11 An embodiment of a head mounted display worn on a user is schematically shown. DETAILED DESCRIPTION

[0038] The present invention will now be described more fully below with reference to the accompanying drawings showing various embodiments. However, the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and the scope of the present invention will be fully conveyed to those skilled in the art. The same reference numerals always refer to the same elements.

[0039] It will be understood that when an element is referred to as being "on" another element, the element can be directly on the other element or intervening elements may be present between the element and the other element. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0040] It will be understood that, although the terms "first", "second", "third", etc. can be used in this article to describe various elements, components, areas, layers and / or parts, these elements, components, areas, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer or part from another element, component, area, layer or part. Therefore, without departing from the teachings herein, the "first element", "first component", "first area", "first layer" or "first part" discussed below can be referred to as the second element, second component, second area, second layer or second part.

[0041] The terms used herein are only used to describe the purpose of specific embodiments, and are not intended to be limited. Unless the context clearly indicates otherwise, as used herein, "one", "one (kind / person)", "described (the)" and "at least one (kind / person)" do not represent quantitative restrictions, and are intended to include both singular and plural. Therefore, the reference to "described (the)" element after the reference to "one" element in the claim includes one element and multiple described (the) elements. For example, unless the context clearly indicates otherwise, "element" has the same meaning as "at least one element". "At least one (kind / person)" should not be interpreted as limiting "one" or "one (kind / person)". "Or" means "and / or". As used herein, the term "and / or" includes any combination and all combinations of one or more of the related listed items. It will also be understood that the terms “comprises and / or comprising” or “includes and / or including” when used in this specification specify the presence of stated features, regions, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or groups thereof.

[0042] Moreover, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. It will be understood that relative terms are intended to cover different orientations of the device in addition to the orientation depicted in the accompanying drawings. For example, if the device in a figure is turned over, then the element described as being on the "lower" side of the other elements will then be oriented on the "upper" side of the other elements. Therefore, depending on the specific orientation of the accompanying drawings, the term "lower" can cover both the "lower" and "upper" orientations. Similarly, if the device in a figure is turned over, then the element described as being "below" or "under" the other elements will then be oriented "above" the other elements. Therefore, the terms "below..." or "under..." can cover both the upper and lower orientations.

[0043] As used herein, "about" or "approximately" includes the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, taking into account the measurements in question and the errors associated with the measurements of a particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0044] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should also be understood that, unless explicitly defined as such herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the context of the present disclosure, and not interpreted in an idealized or overly formal sense.

[0045] Embodiments are described herein with reference to cross-sectional views as schematic diagrams of idealized embodiments. As such, variations in the shapes of the diagrams due to, for example, manufacturing techniques and / or tolerances are anticipated. Therefore, the embodiments described herein should not be construed as being limited to the specific shapes of the zones shown herein, but rather to deviations in shapes, for example, caused by manufacturing. For example, a zone shown or described as flat may typically have rough and / or nonlinear features. In addition, the sharp corners shown may be rounded. Therefore, the zones shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the zones, and are not intended to limit the scope of the claims.

[0046] Hereinafter, a lens assembly and a display device including the same according to embodiments will be described with reference to the accompanying drawings.

[0047] First, refer to Figure 1 The configuration included in the display device DD is briefly described.

[0048] Figure 1 A display device according to an embodiment is schematically shown.

[0049] In an embodiment, the display device DD may include a display panel DP and a lens assembly OCP.

[0050] The display panel DP is configured to emit light. In some embodiments, the display panel DP can display a moving image or a still image. The display panel DP can be used as a display screen of a portable electronic device such as a mobile phone, a smart phone, a tablet personal computer (PC), a smart watch, a watch phone, a mobile communication terminal, an electronic note, an electronic book, a portable multimedia player (PMP), a navigation device, and an ultra-mobile PC (UMPC), and can be used as a display screen of various products such as a television, a laptop computer, a monitor, a billboard, and an Internet of Things (IOT) device. However, the application field of the display panel DP is not limited to a specific example.

[0051] The lens assembly OCP may transmit light provided (or emitted) from the display panel DP. The lens assembly OCP may guide the light provided from the display panel DP. The lens assembly OCP may guide the light provided from the display panel DP to increase the area (observation window or eye box) in which the user can observe the image. Therefore, the lens assembly OCP may effectively provide virtual reality or augmented reality to the user.

[0052] The lens assembly OCP may be disposed on the display panel DP. In some embodiments, the lens assembly OCP may be disposed to be spaced apart from the display panel DP by a predetermined distance. In some embodiments, the lens assembly OCP may be directly disposed on the display panel DP.

[0053] In the following, reference will be made to Figure 2 The display panel DP of the display device DD is described.

[0054] Figure 2 A schematic top plan view of a display panel according to an embodiment is shown.

[0055] Reference Figure 2 , an embodiment of the display panel DP includes a base layer BSL on a plane defined based on a first direction DR1 and a second direction DR2 crossing the first direction DR1, and a light emitting element disposed on the base layer BSL.

[0056] The display panel DP may be formed in a flat shape having a rectangular shape having a short side in a first direction DR1 and a long side in a second direction DR2 (different from the first direction DR1) intersecting the first direction DR1. The corners where the short side of the first direction DR1 and the long side of the second direction DR2 intersect may be rounded to have a predetermined curvature, or may be formed to have a right angle. The flat shape of the display panel DP is not limited to a quadrilateral shape, and may be formed in a rounded shape such as another polygonal shape, a circular shape, or an elliptical shape. The display panel DP may be formed to be flat, but is not limited thereto. In an embodiment, for example, the display panel DP may include a curved portion formed at the left and right ends, and have a constant curvature or a variable curvature. In addition, the display panel DP may be formed to be flexible (e.g., may be bent, curved, folded, or curled).

[0057] In the present disclosure, the first direction DR1 is the row direction of the pixels PXL, which may also be referred to as the "horizontal" direction. The second direction DR2 may be the column direction of the pixels PXL, which may also be referred to as the "vertical" direction. The first direction DR1 and the second direction DR2 may be perpendicular to each other. The third direction DR3 may be the display direction of the display panel DP, or the normal direction of the plane on which the base layer BSL is set. The third direction DR3 may be the thickness direction of the display panel DP or the base layer BSL.

[0058] The display panel DP may include a display area DA and a non-display area NDA. The non-display area NDA may mean an area other than the display area DA. The non-display area NDA may surround at least a portion of the display area DA.

[0059] The display area DA may refer to an area in which the pixels PXL are disposed. The non-display area NDA may refer to an area in which the pixels PXL are not disposed. In the non-display area NDA, a driving circuit part, wirings, and pads connected to the pixels PXL of the display area DA may be disposed.

[0060] In some embodiments, the pixel PXL (or sub-pixel SPX) may include a first sub-pixel SPX1, a second sub-pixel SPX2, and a third sub-pixel SPX3. At least one selected from the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may form or collectively define a pixel unit PXU capable of emitting light of various colors. Figure 2 An embodiment is shown in which each of the plurality of pixels PXL includes three sub-pixels SPX1 , SPX2 , and SPX3 , ie, a first sub-pixel SPX1 , a second sub-pixel SPX2 , and a third sub-pixel SPX3 , but the present invention is not limited thereto.

[0061] In some embodiments, the pixel PXL (or sub-pixel SPX) may be arranged in a stripe or However, the present disclosure is not necessarily limited thereto.

[0062] The first sub-pixel SPX1 may emit a first light, the second sub-pixel SPX2 may emit a second light, and the third sub-pixel SPX3 may emit a third light. Here, the first light may be light of a red band, the second light may be light of a green band, and the third light may be light of a blue band. The red band is a band of about 600 nanometers (nm) to about 750 nm, the green band is a band of about 480 nm to about 560 nm, and the blue band may be a band of about 370 nm to about 460 nm, but is not limited thereto.

[0063] Each of the first subpixel SPX1, the second subpixel SPX2, and the third subpixel SPX3 may include an inorganic light emitting element including an inorganic semiconductor, or an organic light emitting diode (OLED) as a light emitting element emitting light. However, the embodiments of the specification are not limited thereto.

[0064] In the following, reference will be made to Figures 3 to 6 A lens assembly OCP according to an embodiment is described.

[0065] Figure 3A schematic cross-sectional view of a lens assembly according to an embodiment is shown. Figure 4 The light paths of the side light and the front light emitted from the display panel are schematically shown. Figure 4 Shows Figure 3 area S1 and the display panel DP. FIG. 5A to FIG. 5F The TECH WIZ 1D simulation results of the outgoing light according to the presence or absence of the phase retardation layer and the phase retardation value of the phase retardation layer are shown. Figure 6 The path of the light path being folded is schematically shown. Figure 6 Shows Figure 3 area S2.

[0066] For reference, TECH WIZ is one of several optical simulation programs known in the art.

[0067] Reference Figure 3 The lens assembly OCP may include a lens assembly that can be aligned with the display panel DP in the third direction DR3 (eg, see Figure 1 ) is an incident side A1 arranged adjacent to the incident side A1 and an exit side A2 opposite to the incident side A1.

[0068] The lens assembly OCP may include a first polarizing layer POL1, a phase retardation layer RTHL, a second polarizing layer POL2, a first quarter wave plate QWP1, a partial reflector layer HFM, a second quarter wave plate QWP2, and a third polarizing layer POL3. In some embodiments, the lens assembly OCP may have a structure in which the first polarizing layer POL1, the phase retardation layer RTHL, the second polarizing layer POL2, the first quarter wave plate QWP1, the partial reflector layer HFM, the second quarter wave plate QWP2, and the third polarizing layer POL3 are sequentially arranged.

[0069] In the drawings of the present disclosure, the components of the lens assembly OCP are shown as having flat surfaces, and the cross-sections of the components of the lens assembly OCP are shown as having quadrilateral shapes, but the present disclosure is not limited thereto. In some embodiments, each of the multiple components of the lens assembly OCP may have a concave surface or a convex surface, and the cross-sections of each of the multiple components of the lens assembly OCP may be concave or convex.

[0070] In an embodiment of the lens assembly OCP, a first polarizing layer POL1 may be disposed on the display panel DP relative to a third direction DR3. The first polarizing layer POL1 may be disposed adjacent to the incident side A1. In an embodiment, for example, the first polarizing layer POL1 may be disposed closer to the display panel DP than the second polarizing layer POL2. In some embodiments, the first polarizing layer POL1 and the display panel DP may be physically spaced apart from each other. The first polarizing layer POL1 and the display panel DP may not contact each other. However, the present disclosure is not limited thereto. In an embodiment, the first polarizing layer POL1 may be disposed directly on the display panel DP to contact the display panel DP.

[0071] The first polarizing layer POL1 may have a transmission axis (e.g., a light transmission axis) (or a passing axis) aligned along a predetermined direction. For example, the first polarizing layer POL1 may have a transmission axis aligned along a fourth direction DR4, which is a direction perpendicular to the third direction DR3. The fourth direction DR4 may be parallel to Figure 2 . The first polarization layer POL1 may be a linear polarization layer. The first polarization layer POL1 may be in a film shape. The first polarization layer POL1 may linearly polarize non-polarized or partially polarized light emitted from the display panel DP. In an embodiment, for example, the first polarization layer POL1 may transmit only a component of light vibrating along a transmission axis of the first polarization layer POL1, and not transmit the remaining component of the light. Therefore, as the light emitted from the display panel DP passes through the first polarization layer POL1, the light may be aligned with the transmission axis of the first polarization layer POL1 and be linearly polarized.

[0072] The second polarization layer POL2 may be disposed on the first polarization layer POL1 relative to the third direction DR3. The second polarization layer POL2 may be disposed between the exit side A2 and the first polarization layer POL1. The second polarization layer POL2 may be disposed farther from the incident side A1 than the first polarization layer POL1. For example, the second polarization layer POL2 may be disposed closer to the exit side A2 than the first polarization layer POL1. The second polarization layer POL2 may be disposed farther from the display panel DP than the first polarization layer POL1.

[0073] The second polarization layer POL2 may have a transmission axis (or a transmission axis) aligned along a predetermined direction. The second polarization layer POL2 may have a transmission axis in the same direction as the first polarization layer POL1 (or the transmission axis of the first polarization layer POL1 and the transmission axis of the second polarization layer POL2 are parallel to each other). In an embodiment, for example, the second polarization layer POL2 may have a transmission axis aligned along a fourth direction DR4. The second polarization layer POL2 may be a linear polarization layer. The second polarization layer POL2 may linearly polarize light passing through the second polarization layer POL2. For example, the second polarization layer POL2 may transmit only a component of light vibrating along the transmission axis of the second polarization layer POL2, and may not transmit the remaining components of the light.

[0074] The phase retardation layer RTHL may be disposed on the first polarization layer POL1 relative to the third direction DR3. The phase retardation layer RTHL may be disposed adjacent to the first polarization layer POL1. The phase retardation layer RTHL may be disposed between the first polarization layer POL1 and the second polarization layer POL2. The phase retardation layer RTHL may be disposed to be spaced apart from the first polarization layer POL1 and the second polarization layer POL2 and disposed between the first polarization layer POL1 and the second polarization layer POL2. The phase retardation layer RTHL may not be in contact with the first polarization layer POL1 and the second polarization layer POL2.

[0075] The material with isotropic refractive index (or the material with isotropic refractive index) may be filled between the phase retardation layer RTHL and the first polarization layer POL1 and between the phase retardation layer RTHL and the second polarization layer POL2. In an embodiment, for example, air may be filled between the phase retardation layer RTHL and the first polarization layer POL1 and between the phase retardation layer RTHL and the second polarization layer POL2.

[0076] The phase retardation layer RTHL may have a phase retardation value within a numerical range. The phase retardation value may be represented by Equation 1 below.

[0077] [Equation 1]

[0078] R th ={(N X +N Y ) / 2-N Z}×d

[0079] In Equation 1, R th represents the phase delay value of the phase delay layer RTHL, N X represents the refractive index of the phase retardation layer RTHL in the first direction DR1, N Y represents the refractive index of the phase retardation layer RTHL in the second direction DR2, N Zdenotes a refractive index of the phase retardation layer RTHL in the third direction DR3, and d denotes a thickness D of the phase retardation layer RTHL.

[0080] In the present disclosure, the thickness D is defined in the third direction DR3, and the first direction DR1 and the second direction DR2 are the same as the direction in which the plane in which the phase retardation layer RTHL is disposed extends. X 、N Y and N Z The phase retardation layer RTHL may have a first phase retardation refractive index (N ) along the first direction DR1. X The phase retardation layer RTHL may have a second phase retardation refractive index (N ) along the second direction DR2. Y The phase retardation layer RTHL may have a third phase retardation refractive index (N ) along a third direction DR3 perpendicular to the first direction DR1 and the second direction DR2. Z ).

[0081] The first phase retardation refractive index (N X ) and the second phase retardation refractive index (N Y ) is a refractive index of a plane of the phase retardation layer RTHL (eg, a plane on which the phase retardation layer RTHL is disposed), and may have the same value as each other. The third phase retardation refractive index (N Z ) is a refractive index in the thickness direction (eg, the third direction DR3), and may be related to the first phase delay refractive index (N X ) and the second phase retardation refractive index (N Y ) has different values. The third phase retardation refractive index (N Z ) may have a refractive index relative to the first phase delay (N X ) and the second phase retardation refractive index (N Y ). Therefore, the polarization state of light incident on the phase retardation layer RTHL can be changed by forming an angle relative to the third direction DR3 (or along a direction different from the third direction DR3).

[0082] In some embodiments, each of the first phase-retarding refractive index, the second phase-retarding refractive index, and the third phase-retarding refractive index may be in a range of about 1.5 to about 1.9. However, the present disclosure is not limited thereto.

[0083] The phase retardation layer RTHL may have a phase retardation value in the range of about 500 nm to about 1500 nm with respect to visible light (e.g., light having a wavelength of about 400 nm to about 700 nm). The phase retardation value may be determined according to process conditions. For example, when the “(N X +N Y ) / 2-N Z ” When the liquid crystal is vertically aligned and the phase retardation layer RTHL has a thickness of about 3.5 micrometers (μm), the phase retardation value may be about 525 nm (=0.15×3.5 μm).

[0084] The phase retardation layer RTHL may include a material having a refractive index anisotropy. In an embodiment, for example, the material having a refractive index anisotropy may include a liquid crystal material. In an embodiment, for example, the material having a refractive index anisotropy may include a reactive liquid crystal element. In an embodiment, for example, the material having a refractive index anisotropy may include a disc-shaped material (e.g., a disc-shaped liquid crystal element).

[0085] In some embodiments, the phase retardation layer RTHL may be a film layer. The phase retardation layer RTHL may be a single film layer.

[0086] Reference Figure 4 , the display panel DP (eg, the light emitting element of the display panel DP) may emit light similar to Lambertian distribution, and the light emitted from the display panel DP may include front light FLGT and side light SLGT.

[0087] Experimentally, when the display device DD (see Figure 1 ) is implemented as a head mounted display, the front light FLGT and the side light SLGT emitted from the display panel DP may form an image for providing virtual reality and augmented reality to the user. For example, the front light FLGT and the side light SLGT emitted from the display panel DP may pass through the lens assembly OCP (see Figure 3 ) and forms an image in front of the user's eyes.

[0088] The front light FLGT is light emitted in a direction perpendicular to the display panel DP and may be parallel to the third direction DR3. The side light SLGT is light emitted in a direction not perpendicular to the display panel DP and may be emitted in a direction forming an angle with respect to the third direction DR3.

[0089] Experimentally, when the display device DD is implemented as a head-mounted display, the front light FLGT may be light that forms a focus in front of the user's eyes and may be chief ray angle (CRA) light that enters the user's viewing angle (or eye box). Because the side light SLGT may not form an appropriate focus, the side light SLGT may form a ghost image to provide a virtual image to the user, and may cause the light emitted from the light emitting element to be mixed.

[0090] The display device DD according to the embodiment of the present disclosure can minimize the loss of the front light FLGT while appropriately minimizing the amount of the side light SLGT emitted outside the lens assembly OCP. Therefore, the display quality of the display device DD can be improved.

[0091] When the front light FLGT is emitted from the display panel DP, passes through the first polarization layer POL1 and passes through the phase delay layer RTHL, the front light FLGT is parallel to the third direction DR3, so that the front light FLGT can pass through without changing the individual light information. That is, when the front light FLGT passes through the phase delay layer RTHL, the front light FLGT can pass through the phase delay layer RTHL without changing the polarization state of the front light FLGT. Therefore, since the polarization state of the front light FLGT that has passed through the phase delay layer RTHL is not changed, the front light FLGT can pass through the second polarization layer POL2. Hereinafter, the light passing through the second polarization layer POL2 is defined as "second polarization layer passing light LGT".

[0092] In such an embodiment, when the side light SLGT is emitted from the display panel DP and passes through the first polarization layer POL1 and the phase delay layer RTHL, since the side light SLGT is incident at an angle relative to the third direction DR3, the polarization state can be changed according to the phase delay value. That is, when the side light SLGT passes through the phase delay layer RTHL, the polarization state of the side light SLGT can be changed. Therefore, among the components of the side light SLGT whose polarization states have been changed after passing through the phase delay layer RTHL, the components that do not vibrate along the transmission axis of the second polarization layer POL2 can be blocked by the second polarization layer POL2. In other words, the polarization state of the side light SLGT can be changed by passing through the phase delay layer RTHL, and at least a portion of the side light SLGT that vibrates in a direction different from the transmission axis of the second polarization layer POL2 may not be allowed to be transmitted through the second polarization layer POL2.

[0093] In this regard, reference will be made to FIG. 5A to FIG. 5F Combined with Figure 1 , Figure 3 and Figure 4 The simulation results of the optical information according to the presence or absence of the phase retardation layer RTHL and the phase retardation value of the phase retardation layer RTHL are described. FIG. 5A to FIG. 5FThe TECH WIZ1D simulation results of the outgoing light according to the presence or absence of the phase retardation layer RTHL and the phase retardation value of the phase retardation layer RTHL are shown. FIG. 5A to FIG. 5F The simulation results shown in are defined as first to sixth images 5A to 5F, respectively.

[0094] exist FIG. 5A to FIG. 5F , the first image 5A is a simulation result of light emitted from a lens component OCP in which a phase retardation layer RTHL is not provided. The second image 5B is a simulation result of light emitted from a lens component OCP in which the phase retardation layer RTHL is set to have a phase retardation value of 300nm. The third image 5C is a simulation result of light emitted from a lens component OCP in which the phase retardation layer RTHL is set to have a phase retardation value of 500nm. The fourth image 5D is a simulation result of light emitted from a lens component OCP in which the phase retardation layer RTHL is set to have a phase retardation value of 1000nm. The fifth image 5E is a simulation result of light emitted from a lens component OCP in which the phase retardation layer RTHL is set to have a phase retardation value of 1500nm. The sixth image 5F is a simulation result of light emitted from a lens component OCP in which the phase retardation layer RTHL is set to have a phase retardation value of 1800nm.

[0095] These images show the viewing angle distribution of transmittance for each light. For each brightness and darkness, the transmittance of the light corresponds to Vlax shown on the right, and the unit of the transmittance is au (arbitrary unit).

[0096] Comparing the first image 5A with the second image 5B to the sixth image 5F, it can be seen that the first image 5A has a dark result value (for example, a value of Vlax 30 to 40) in a relatively large area corresponding to the center when compared with the second image 5B to the sixth image 5F. In the TECH WIZ 1D simulation result, the relatively dark result values ​​corresponding to the values ​​of Vlax 30 to 40 are widely distributed in the central area, which means that the emittance of the side light SLGT from the outgoing light is large. That is, comparing the first image 5A with the second image 5B to the sixth image 5F, it can be seen that more side light SLGT may be generated in the lens component OCP in which the phase retardation layer RTHL is not provided.

[0097] Comparing the second image 5B with the third image 5C, it can be seen that the second image 5B has a dark result value in a relatively large area when compared with the third image 5C. This may be because when the phase retardation value of the phase retardation layer RTHL is less than 500nm, only a small amount of the side light SGLT in the outgoing light is blocked. Experimentally, when only a small amount of the side light SGLT in the outgoing light is blocked, a ghost image may often be formed. Therefore, when the phase retardation layer RTHL is formed to have a phase retardation value less than 500nm, only a small amount of the side light SGLT is blocked, so that a ghost image may often be formed.

[0098] Comparing the fifth image 5E with the sixth image 5F, it can be seen that the sixth image 5F has a relatively narrow black result value (e.g., a value of Vlax 0 to 5) in the area adjacent to the edge area in the diagonal direction when compared with the fifth image 5E. Experimentally, the reduction of the black portion (e.g., the area with a value of Vlax 0 to 5) in the edge area may mean that the brightness of the emitted light is reduced. Therefore, this may indicate that when the phase delay value of the phase delay layer RTHL exceeds 1500nm, the brightness of the display device DD may be excessively reduced. As a result, when the phase delay layer RTHL is formed to have a phase delay value exceeding 1500nm, the brightness of the display device DD may be excessively reduced to degrade the quality of the display device DD.

[0099] Therefore, it is desirable to design or set the phase retardation layer RTHL by selecting a proper range of phase retardation values ​​that can properly block the side light SLGT without excessively reducing the brightness.

[0100] Reference Figure 3 and Figure 6 In an embodiment of the lens assembly OCP, the first quarter wave plate QWP1 may be disposed on the second polarizing layer POL2 relative to the third direction DR3. The first quarter wave plate QWP1 may be disposed adjacent to the second polarizing layer POL2. The first quarter wave plate QWP1 may be disposed between the second polarizing layer POL2 and the exit side A2. In some embodiments, the first quarter wave plate QWP1 may be physically spaced apart from the second polarizing layer POL2. The first quarter wave plate QWP1 may not contact the second polarizing layer POL2.

[0101] The first quarter wave plate QWP1 may have an optical axis aligned at approximately 45 degrees relative to the transmission axis of the first polarization layer POL1 and the second polarization layer POL2. By providing a phase difference of λ / 4, the first quarter wave plate QWP1 may change linear polarized light into circular polarized light, or change circular polarized light into linear polarized light. In an embodiment, for example, when the second polarization layer passing light LGT is 0° linear polarized light, and when the second polarization layer passing light LGT passes through the first quarter wave plate QWP1, the second polarization layer passing light LGT may become the first light L1 of left-handed circular polarization (LCP). In some embodiments, when the second polarization layer passing light LGT passes through the first quarter wave plate QWP1, the second polarization layer passing light LGT may be right-handed circularly polarized (RCP), but in the present disclosure, for convenience, an embodiment in which the second polarization layer passing light LGT is left-handed circularly polarized will be mainly described.

[0102] A material having an isotropic refractive index may be filled between the first quarter wave plate QWP1 and the second polarization layer POL2. In an embodiment, for example, air may be filled between the first quarter wave plate QWP1 and the second polarization layer POL2.

[0103] The partial mirror layer HFM may be disposed on the first quarter wave plate QWP1 relative to the third direction DR3. The partial mirror layer HFM may be disposed adjacent to the first quarter wave plate QWP1. The partial mirror layer HFM may be disposed between the first quarter wave plate QWP1 and the exit side A2. In some embodiments, the partial mirror layer HFM may be physically spaced apart from the first quarter wave plate QWP1. The partial mirror layer HFM may not contact the first quarter wave plate QWP1.

[0104] The partially reflective mirror layer HFM may comprise a metallic mirror coating or other mirror coatings such as a 50% transparent and 50% reflective dielectric multilayer coating on its surface.

[0105] At least a portion of the first light L1 may pass through the partial reflective mirror layer HFM to become the second light L2. The polarization state of the first light L1 and the polarization state of the second light L2 may be identical to each other.

[0106] A material with isotropic refractive index (or a material having isotropic refractive index) may be filled between the partial mirror layer HFM and the first quarter wave plate QWP1. In an embodiment, for example, air may be filled between the partial mirror layer HFM and the first quarter wave plate QWP1.

[0107] The second quarter wave plate QWP2 may be disposed on the partial mirror layer HFM relative to the third direction DR3. The second quarter wave plate QWP2 may be disposed adjacent to the partial mirror layer HFM. The second quarter wave plate QWP2 may be disposed between the partial mirror layer HFM and the exit side A2. In some embodiments, the second quarter wave plate QWP2 may be physically spaced apart from the partial mirror layer HFM. The second quarter wave plate QWP2 may not be in contact with the partial mirror layer HFM.

[0108] The second quarter wave plate QWP2 may provide a phase difference of λ / 4 so that the second polarization layer passing light LGT is vertically polarized. The second polarization layer passing light LGT may be vertically polarized to become the third light L3. For example, when the second polarization layer passing light LGT is a linear polarized light having a transmission axis of 0° relative to the transmission axis of the first polarization layer POL1 and the transmission axis of the second polarization layer POL2, the second polarization layer passing light LGT may pass through the first quarter wave plate QWP1 and the second quarter wave plate QWP2 to be polarized to be a linear polarized light having a transmission axis of 90° relative to the transmission axis of the first polarization layer POL1 and the second polarization layer POL2.

[0109] The material with isotropic refractive index may be filled between the second quarter wave plate QWP2 and the partial mirror layer HFM. In an embodiment, for example, air may be filled between the second quarter wave plate QWP2 and the partial mirror layer HFM.

[0110] The third polarization layer POL3 may be disposed on the second quarter wave plate QWP2 relative to the third direction DR3. The third polarization layer POL3 may be disposed adjacent to the exit side A2. The third polarization layer POL3 may be disposed adjacent to the second quarter wave plate QWP2. In some embodiments, the third polarization layer POL3 may be physically spaced apart from the second quarter wave plate QWP2. The third polarization layer POL3 may not contact the second quarter wave plate QWP2.

[0111] The refractive index isotropic material may be filled between the third polarization layer POL3 and the second quarter wave plate QWP2. In an embodiment, for example, air may be filled between the third polarization layer POL3 and the second quarter wave plate QWP2.

[0112] The third polarizing layer POL3 may have a transmission axis (or a passing axis) aligned along a predetermined direction. In an embodiment, for example, the third polarizing layer POL3 may have a transmission axis aligned along a fourth direction DR4. The third polarizing layer POL3 may be a reflective polarizing layer. In an embodiment, for example, the third polarizing layer POL3 may transmit only a component of light vibrating along the transmission axis of the third polarizing layer POL3, and may reflect the remaining component of the light.

[0113] Therefore, when the light LGT passing through the second polarization layer is a linear polarized light of 0° relative to the transmission axis of the first polarization layer POL1 and the second polarization layer POL2, and the third light L3 is a linear polarized light of 90° relative to the transmission axis of the first polarization layer POL1 and the second polarization layer POL2, the third light L3 can be reflected from the third polarization layer POL3 to become the fourth light L4.

[0114] The fourth light L4 may pass through the second quarter wave plate QWP2 again to become the fifth light L5 of right circular polarization. The fifth light L5 of right circular polarization may be reflected from the partial reflector layer HFM. In this case, when the circularly polarized light is reflected, the phase may change by 180°, and the fifth light L5 of right circular polarization may be reflected from the partial reflector layer HFM to become the sixth light L6 of left circular polarization. The sixth light L6 of left circular polarization may pass through the second quarter wave plate QWP2 again to become the seventh light L7 of linear polarized light of 0° relative to the transmission axis of the first polarization layer POL1 and the second polarization layer POL2.

[0115] As a result, the second polarizing layer passing light LGT and the seventh light L7 may have the same polarization value or state, and the seventh light L7 may pass through the third polarizing layer POL3.

[0116] In the embodiment, as described above, while the light emitted from the display panel DP passes through the second polarizing layer POL2, the first quarter wave plate QWP1, the partial mirror layer HFM, the second quarter wave plate QWP2, and the third polarizing layer POL3, the light path may be folded, and the light path may increase the distance between the third polarizing layer POL3 and the partial mirror layer HFM. Therefore, compared with the case where the lens assembly OCP does not include the second polarizing layer POL2, the first quarter wave plate QWP1, the partial mirror layer HFM, the second quarter wave plate QWP2, and the third polarizing layer POL3, the lens assembly OCP may be formed close to the focus, and the thickness of the display device DD may be reduced.

[0117] In the following, reference will be made to Figure 7 A lens assembly OCP' according to another embodiment is described. Figure 7 A schematic cross-sectional view of a lens assembly according to another embodiment is shown.

[0118] In addition to the phase retardation layer RTHL' being adhered (or bonded) to the first polarization layer POL1 through the adhesive layer 101, Figure 7 The lens assembly OCP' shown in Figure 3The lens assembly OCP shown in FIG. 1 is substantially the same. However, the position of the phase retardation layer RTHL' is not limited thereto, and in some embodiments, the phase retardation layer RTHL' may be adhered to the lower portion of the second polarizing layer POL2 by an adhesive layer 101. For ease of description, repeated detailed descriptions of elements identical or similar to those described above will be omitted or simplified.

[0119] In an embodiment, Figure 7 As shown in FIG. 1 , the phase retardation layer RTHL′ may be adhered to (or coupled to) the first polarizing layer POL1 through an adhesive layer 101 to form a phase retardation film attached to the first polarizing layer POL1 .

[0120] The adhesive layer 101 may include an optically isotropic material.

[0121] The adhesive layer 101 may include a flexible material. In some embodiments, the flexible material may include at least one selected from polyimide, polyethylene terephthalate, and polyethylene phthalate.

[0122] The adhesive layer 101 may include at least one selected from a pressure sensitive adhesive (PSA) and an optically clear adhesive (OCA). However, the present disclosure is not limited thereto.

[0123] In the following, reference will be made to Figure 8 A lens assembly OCP is described according to another embodiment. Figure 8 A schematic cross-sectional view of a lens assembly according to another embodiment is shown.

[0124] In addition to the phase retardation layer RTHL" being directly disposed on the first polarization layer POL1, Figure 8 The lens assembly shown in the OCP" Figure 3 The lens assembly OCP shown in FIG. 1 is substantially the same. However, the position of the phase retardation layer RTHL'' is not limited thereto, and in some embodiments, the phase retardation layer RTHL'' may be disposed directly below the second polarization layer POL2.

[0125] For convenience of description, repeated detailed descriptions of elements that are the same as or similar to those described above will be omitted or simplified.

[0126] In an embodiment, Figure 8 As shown in FIG. 1 , the phase retardation layer RTHL” can be directly disposed on the first polarization layer POL1 by a coating or deposition process.

[0127] In an embodiment, for example, the phase retardation layer RTHL' may be provided by directly coating or depositing a material having a phase retardation value in the range of about 500 nm to about 1500 nm on the first polarizing layer POL1.

[0128] The coating or deposition process can be performed by methods commonly used in the art. In an embodiment, for example, one or more of the coating processes such as spin coating, roller coating, rod coating, dip coating, gravure coating, curtain coating, die coating, spray coating, blade coating, and kneader coating can be used. In an embodiment, for example, one or more of a deposition process such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and plasma enhanced chemical vapor deposition (PECVD) and a printing process such as screen printing, spray printing, inkjet printing, iron plate printing, single plate printing, and lithographic printing can be used.

[0129] Fig. 9 and Fig.10 The schematic diagram shows the application Figure 1 An embodiment of an electronic device of a display device.

[0130] Reference Fig. 9 , display device DD (see Figure 1 ) can be implemented as a head mounted display 2000. The head mounted display 2000 may be a wearable electronic device that can be worn on the head of a user. The head mounted display 2000 may include a head mounting band 2100 and a display device accommodating housing 2200.

[0131] The head mounting band 2100 may be connected to the display device accommodating housing 2200 to fix the display device accommodating housing 2200. Fig. 9 As shown in , the head mounting band 2100 includes a horizontal band and a vertical band for fixing the head mounted display 2000 to the user's head, the horizontal band can surround the side portion of the user's head, and the vertical band can surround the upper portion of the user's head. However, the present disclosure is not necessarily limited thereto, and the head mounting band 2100 can be implemented in the form of a glasses frame or a helmet.

[0132] Reference Fig.10 , display device DD (see Figure 1 ) may be implemented as smart glasses 1000 as another form of head-mounted display. The smart glasses 1000 may include a frame 111 and a lens portion 112. The smart glasses 1000 are wearable electronic devices that can be worn on the face of a user, and may have a structure in which a portion of the frame 111 is folded or unfolded. For example, the smart glasses 1000 may be a wearable device for augmented reality. However, the present disclosure is not limited thereto.

[0133] The frame 111 may include a housing 111b supporting the lens portion 112 and a leg portion 111a for a user to wear. The leg portion 111a may be coupled to the housing 111b by a hinge to be folded or unfolded.

[0134] A battery, a touch pad, a microphone, and / or a camera may be embedded in the frame 111. In addition, a projector that outputs light and / or a processor that controls a light signal, etc. may be embedded in the frame 111.

[0135] The lens portion 112 may be an optical member that transmits light or reflects light. The lens portion 112 may include glass and / or a transparent synthetic resin.

[0136] The display device DD may be applied to the lens portion 112 of the smart glasses 1000. For example, the user may recognize an image displayed by an optical signal transmitted from the projector of the frame 111 through the lens portion 112. For example, the user may recognize information such as time and date displayed in the lens portion 112.

[0137] Fig.11 An embodiment of a head mounted display worn on a user is schematically shown.

[0138] Reference Fig.11 , the first display panel DP1 and the second display panel DP2 are provided in the head mounted display 2000. The head mounted display 2000 may further include one or more lenses LOCP and ROCP. The lenses LOCP and ROCP may correspond to the above-mentioned lens assembly OCP. Fig.11 The head mounted display 2000 shown in FIG. 1 may correspond to Fig. 9 The embodiment shown in .

[0139] In the display device accommodating housing 2200, a right-eye lens ROCP may be disposed between the first display panel DP1 and the right eye of the user. In the display device accommodating housing 2200, a left-eye lens LOCP may be disposed between the second display panel DP2 and the left eye of the user.

[0140] The image output from the first display panel DP1 may be displayed to the right eye of the user through the right eye lens ROCP. The right eye lens ROCP may refract the light from the first display panel DP1 to be directed to the right eye of the user. The right eye lens ROCP may perform an optical function to adjust the viewing distance between the first display panel DP1 and the right eye of the user.

[0141] The image output from the second display panel DP2 may be displayed to the left eye of the user through the left eye lens LOCP. The left eye lens LOCP may refract the light from the second display panel DP2 to be directed to the left eye of the user. The left eye lens LOCP may perform an optical function to adjust the viewing distance between the second display panel DP2 and the left eye of the user.

[0142] In an embodiment, each of the right-eye lens ROCP and the left-eye lens LOCP may include an optical lens having a flat cross-section. The optical lens having a flat cross-section may include Figure 3 , a second polarization layer POL2, a first quarter wave plate QWP1, a partial reflector layer HFM, a second quarter wave plate QWP2 and a third polarization layer POL3 are shown in FIG.

[0143] In an embodiment, each of the right eye lens ROCP and the left eye lens LOCP may include a multi-channel lens including sub-regions having different optical characteristics. In such an embodiment, each display panel outputs an image corresponding to a sub-region of the multi-channel lens, and the output image can pass through the sub-region and be viewed by the user.

[0144] The present invention should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art.

[0145] While the invention has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit or scope of the invention as defined by the appended claims.

Claims

1. A lens assembly comprising an incident side where light is incident and an exit side opposite to the incident side, wherein: The lens assembly comprises: A first polarizing layer is disposed adjacent to the incident side; A second polarizing layer, disposed between the first polarizing layer and the exit side; A phase retardation layer, disposed between the first polarization layer and the second polarization layer; A first quarter wave plate, disposed between the second polarization layer and the exit side; a partial reflector layer disposed between the first quarter wave plate and the exit side; a second quarter wave plate disposed between the partial reflector layer and the exit side; and A third polarizing layer is disposed adjacent to the exit side, The phase retardation layer has a first phase retardation refractive index along a first direction, a second phase retardation refractive index along a second direction that is equal to the first phase retardation refractive index, and a third phase retardation refractive index along a third direction that is perpendicular to the first direction and the second direction, and Wherein, the first phase-retardation refractive index and the second phase-retardation refractive index are different from the third phase-retardation refractive index.

2. The lens assembly according to claim 1, wherein: The phase retardation layer includes a material having a refractive index anisotropy.

3. The lens assembly according to claim 2, wherein: The phase retardation layer has a phase retardation value in the range of 500nm to 1500nm with respect to visible light, Wherein, the phase delay value of the phase delay layer is R th It expresses and satisfies the following equation: R th ={(N X +N Y ) / 2-N Z }×d, in, N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

4. The lens assembly according to claim 2, wherein: The material having refractive index anisotropy includes a discotic material or a liquid crystal material.

5. The lens assembly according to claim 3, wherein: Each of the first to third phase-retarding refractive indices is in a range of 1.5 to 1.

9.

6. The lens assembly according to claim 3, wherein: The phase retardation layer changes the polarization state of light incident in a direction different from the third direction, and The first direction and the second direction are the same as a direction in which a plane in which the phase retardation layer is disposed extends.

7. The lens assembly according to claim 3, wherein: A light transmission axis of the first polarizing layer and a light transmission axis of the second polarizing layer are parallel to each other.

8. The lens assembly according to claim 3, wherein: The first polarizing layer is a linear polarizing layer.

9. The lens assembly according to claim 3, wherein: The first polarizing layer is in a film shape.

10. The lens assembly according to claim 9, wherein: The first polarization layer and the phase retardation layer are spaced apart from each other.

11. The lens assembly according to claim 10, wherein: The material having isotropic refractive index is disposed between the first polarization layer and the phase retardation layer.

12. The lens assembly according to claim 9, wherein: The lens assembly further comprises: an adhesive layer disposed between the first polarizing layer and the phase retardation layer, Wherein, the phase retardation layer is coupled to the first polarization layer through the adhesive layer.

13. The lens assembly according to claim 3, wherein: The phase retardation layer and the first polarization layer contact each other.

14. The lens assembly of claim 13, wherein: The phase retardation layer is a layer formed on the first polarizing layer through a coating or deposition process.

15. A display device, wherein: The display device comprises: A display panel including a base layer disposed on a plane defined based on a first direction and a second direction different from the first direction, and a light emitting element disposed on the base layer; and a lens assembly disposed on the display panel, wherein the lens assembly transmits light provided from the display panel, and the lens assembly includes an incident side adjacent to the display panel and an exit side opposite to the incident side, Wherein, the lens assembly comprises: A first polarizing layer is disposed adjacent to the incident side; A second polarizing layer, disposed between the first polarizing layer and the exit side; A phase retardation layer, disposed between the first polarization layer and the second polarization layer; A first quarter wave plate, disposed between the second polarization layer and the exit side; a partial reflector layer disposed between the first quarter wave plate and the exit side; a second quarter wave plate disposed between the partial reflector layer and the exit side; and A third polarizing layer is disposed adjacent to the exit side, wherein the phase retardation layer has a first phase retardation refractive index along the first direction, a second phase retardation refractive index along the second direction that is equal to the first phase retardation refractive index, and a third phase retardation refractive index along a third direction perpendicular to the first direction and the second direction, and The first phase-retarding refractive index and the second phase-retarding refractive index are different from the third phase-retarding refractive index.

16. The display device according to claim 15, wherein: The phase retardation layer has a phase retardation value in the range of 500nm to 1500nm with respect to visible light, Wherein, the phase delay value of the phase delay layer is R th It expresses and satisfies the following equation: R th ={(N X +N Y ) / 2-N Z }×d, in, N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

17. The display device according to claim 16, wherein: The phase retardation layer includes a material having anisotropy of refractive index, and The phase retardation layer changes a polarization state of light incident in a direction different from the third direction.

18. The display device according to claim 16, wherein: A light transmission axis of the first polarizing layer, a light transmission axis of the second polarizing layer, and a light transmission axis of the third polarizing layer are parallel to each other.

19. A lens assembly comprising an incident side where light is incident and an exit side opposite to the incident side, wherein: The lens assembly comprises: A first polarizing layer is disposed adjacent to the incident side; A second polarizing layer, disposed between the first polarizing layer and the exit side; a phase delay layer, disposed between the first polarization layer and the second polarization layer, The phase retardation layer has a first phase retardation refractive index along a first direction, a second phase retardation refractive index along a second direction that is equal to the first phase retardation refractive index, and a third phase retardation refractive index along a third direction perpendicular to the first direction and the second direction, and The first phase-retarding refractive index and the second phase-retarding refractive index are different from the third phase-retarding refractive index.

20. The lens assembly of claim 19, wherein: The phase retardation layer has a phase retardation value in the range of 500nm to 1500nm with respect to visible light, Wherein, the phase delay value of the phase delay layer is R th It expresses and satisfies the following equation: R th ={(N X +N Y ) / 2-N Z }×d, in, N X represents the first phase retardation refractive index, N Y represents the second phase retardation refractive index, N Z represents the third phase retardation refractive index, and d represents the thickness of the phase retardation layer.

Images