Stereoscopic image display device

Abstract

A stereoscopic image display device is provided, comprising at least: a display portion having light-emitting devices, a first polarizing plate, and a pancake lens assembly. The first polarizing plate includes: a first polarizer; a first retardation layer bonded to the display portion side of the first polarizer; and a second retardation layer bonded to the assembly side of the first polarizer. The pancake lens assembly includes the retardation layer, the slow axis of the second retardation layer is substantially orthogonal to the slow axis of the retardation layer in the pancake lens assembly, the short-wavelength dispersion is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.04.

Description

Technical Field

[0001] This invention relates to a stereoscopic image display device. Background Technology

[0002] In recent years, display devices have evolved from simply displaying images on a flat surface to displaying stereoscopic images, attracting much attention.

[0003] As a device for displaying stereoscopic images, the use of pancake lenses is known. However, the stereoscopic images provided by this method have limitations in improving resolution. Resolution refers to the contrast difference between bright and dark areas within the image of the aforementioned device.

[0004] The background technology of this invention is disclosed in Korean Patent Publication No. 10-2013-0103595, etc. Summary of the Invention

[0005] The problem that the invention aims to solve

[0006] A stereoscopic image display device is provided that, because the output of light of the same wavelength is the same, the user perceives the same light output according to the wavelength, while eliminating light leakage at the edge of the viewer's side within the viewing angle and having high resolution.

[0007] Solution for solving the problem

[0008] According to one embodiment, a stereoscopic image display device is provided.

[0009] The aforementioned stereoscopic image display device includes at least: a display unit having light-emitting devices, a first polarizing plate, and a pancake lens assembly. The first polarizing plate includes: a first polarizer; a first retardation layer bonded to the display unit side of the first polarizer; and a second retardation layer bonded to the assembly side of the first polarizer. The pancake lens assembly includes a retardation layer, the slow axis of the second retardation layer is substantially orthogonal to the slow axis of the retardation layer in the pancake lens assembly, and the short-wavelength dispersion of the first retardation layer and the second retardation layer is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.04.

[0010] Invention Effects

[0011] Because the output of light is the same for all wavelengths, users perceive the same light output based on the wavelength, while eliminating light leakage at the edge of the viewer's side within the field of view and providing high resolution. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a stereoscopic image display device according to an embodiment.

[0013] Figure 2 This is a cross-sectional view of the first polarizing plate in one embodiment.

[0014] Figure 3 and Figure 4 This is a diagram illustrating the axial relationship between a first polarizing plate and a phase retardation layer in an assembly according to an embodiment.

[0015] Figure 5 This is a schematic diagram of a stereoscopic image display device according to another embodiment.

[0016] Figure 6 This is a schematic diagram of a stereoscopic image display device according to another embodiment.

[0017] Figure 7 This is a cross-sectional view of the second polarizing plate in one embodiment.

[0018] Figures 8 to 9 This is a diagram illustrating the axial relationship between a first polarizing plate, a second polarizing plate, and a phase retardation layer in an assembly according to an embodiment. Detailed Implementation

[0019] Embodiments of this application are described in detail with reference to the accompanying drawings. However, the technology disclosed in this application is not limited to the embodiments described herein, and can be embodied in other forms. The embodiments described herein are provided only to make the disclosure more thorough and complete, and to fully convey the spirit of the invention to those skilled in the art. To clearly show the components of the device, the width or thickness of the aforementioned components are shown enlarged in the drawings; however, the width or thickness of the aforementioned components in this invention are not limited to the scope of this invention. In the various drawings, the same symbols refer to substantially the same components.

[0020] The terminology used herein is for illustrative purposes only and is not intended to limit the invention. Unless the meaning clearly differs in the context, singular expressions include plural expressions.

[0021] In this specification, "upper part" and "lower part" are defined based on the accompanying drawings. Depending on the viewing position, "upper part" may be changed to "lower part" or "lower part" may be changed to "upper part". The expression "on" or "on" includes not only the case where it is directly above, but also the case where other structures are set in the middle. However, "directly on", "directly above", or "directly formed" refers to the case where no intermediate body or other structures are set in the middle.

[0022] In this specification, the following formula A represents "in-plane phase difference (Re)", the following formula B represents "thickness direction phase difference (Rth)", and the following formula C represents "biaxiality (NZ)".

[0023] [Formula A]

[0024] Re = (nx - ny) × d

[0025] [Formula B]

[0026] Rth = ((nx + ny) / 2 - nz) × d

[0027] [Formula C]

[0028] NZ = (nx - nz) / (nx - ny)

[0029] (In Equations A to C above, nx, ny, and nz are the refractive indices of the optical device along the slow axis, fast axis, and thickness direction, respectively, at the measurement wavelength, and d is the thickness of the optical device (unit: nm).

[0030] The “slow axis” mentioned above refers to the axis with the highest refractive index in the in-plane direction, while the “fast axis” refers to the axis with the lowest refractive index in the in-plane direction.

[0031] In formulas A to C above, "optical device" can be a first retardation layer, a second retardation layer, a protective layer, or a stack of retardation layers. In formulas A to C above, "measuring wavelength" can refer to a wavelength of 450 nm, 550 nm, or 650 nm.

[0032] In this specification, "short wavelength dispersion" is Re(450) / Re(550), "long wavelength dispersion" is Re(650) / Re(550), and Re(450), Re(550), and Re(650) are the in-plane phase differences at wavelengths of 450nm, 550nm, and 650nm, respectively, of the phase difference layer.

[0033] In this specification, "cross transmittance (Tc)" is the average value measured perpendicular to the polarizer and under polarized light conditions at wavelengths from 380 nm to 780 nm.

[0034] In this specification, when a numerical range is described, "X to Y" means above X and below Y (X ≤ and ≤ Y).

[0035] One embodiment of a stereoscopic image display device is capable of realizing artificial reality, or is related to a device for realizing artificial reality. Artificial reality is a form of reality that has been adjusted in some way before being presented or displayed to a user. For example, artificial reality may include virtual reality (VR), augmented reality (AR), mixed reality (MR), hybrid reality, or a combination thereof.

[0036] One embodiment of the stereoscopic image display device includes a pancake lens assembly. The pancake lens assembly allows a user to perceive an artificial reality by adjusting the light path emitted from a display unit having a light-emitting device. The stereoscopic image display device has a first polarizing plate between the display unit and the pancake lens assembly.

[0037] The aforementioned first polarizing plate includes a first phase retardation layer and a second phase retardation layer. The short-wavelength dispersion and long-wavelength dispersion of the first and second phase retardation layers are adjusted to the ranges described below. The slow axis of the second phase retardation layer is substantially orthogonal to the slow axis of the phase retardation layer in the pancake lens assembly. Therefore, in the aforementioned stereoscopic image display device, the output of light at the same wavelength is achieved, allowing the user to perceive the same light output based on the wavelength. Simultaneously, light leakage at the edge of the viewing angle on the viewer's side is eliminated, and resolution is improved. Here, "resolution" refers to the contrast difference between bright and dark areas within the image of the aforementioned device. Higher resolution provides an image without ghosting.

[0038] An embodiment of a stereoscopic image display device includes at least: a display unit having light-emitting devices, a first polarizing plate, and a pancake lens assembly. The first polarizing plate includes: a first polarizer; a first retardation layer bonded to the display unit side of the first polarizer; and a second retardation layer bonded to the assembly side of the first polarizer. The pancake lens assembly includes the retardation layer, the slow axis of the second retardation layer is substantially orthogonal to the slow axis of the retardation layer in the pancake lens assembly, and the short-wavelength dispersion of the first retardation layer and the second retardation layer is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.04.

[0039] The slow axis of the second phase retardation layer is substantially orthogonal to the slow axis of the phase retardation layer in the pancake lens assembly. "Substantially orthogonal" means an angle between -5° and +5° from 90°, preferably 90°. This provides the effect of eliminating ghosting and blocking light leakage due to internal scattering.

[0040] The aforementioned short-wavelength dispersion is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.04. In this invention, two phase retardation layers are disposed on both sides of the polarizer in the first polarizer, such that the slow axis of the second phase retardation layer is substantially orthogonal to the slow axis of the phase retardation layer in the pancake lens assembly, thereby adjusting the short-wavelength and long-wavelength dispersion of the two phase retardation layers. As a result, the stereoscopic image display device can improve the resolution on the viewer's side of the screen and significantly reduce light leakage at the edges.

[0041] If the aforementioned short-wavelength dispersion is less than 0.84, there may be short-wavelength light leakage, resulting in the perception of blue ghosting images.

[0042] If the short-wavelength dispersion is greater than 0.88, there may be long-wavelength light leakage, which could lead to the perception of red ghosting in the image.

[0043] If the aforementioned long-wavelength dispersion is less than 1.01, there may be long-wavelength light leakage, resulting in the perception of red ghosting in the image.

[0044] If the aforementioned long-wavelength dispersion is greater than 1.04, there may be short-wavelength light leakage, resulting in the perception of blue ghosting images.

[0045] In one specific embodiment, the short-wavelength dispersion can be from 0.85 to 0.87, and the long-wavelength dispersion can be from 1.02 to 1.03.

[0046] In one specific embodiment, the first phase difference layer may have essentially the same short-wavelength dispersion as the second phase difference layer. The first phase difference layer may also have essentially the same long-wavelength dispersion as the second phase difference layer. Therefore, the circular polarization degree of each wavelength changes, thereby avoiding the problem of inconsistent light output at different wavelengths, which could lead to an inability to provide a uniform image as perceived by the user. Here, "essentially the same" includes not only the case where the error is 0, but also values ​​in the range from -0.001 to +0.001.

[0047] According to one embodiment, the slow axis of the first phase retardation layer is substantially orthogonal to the slow axis of the second phase retardation layer. "Substantially orthogonal" means an angle within the range of -5 to +5° from 90°, preferably 90°. This helps reduce light loss and makes the output of each wavelength identical, because the light emitted from the display unit is circularly polarized while passing through the first phase retardation layer, and then circularly polarized again sequentially through the polarizer and the second phase retardation layer, resulting in substantially the same degree of circular polarization.

[0048] According to one embodiment, the orthogonal transmittance of the polarizer in the first polarizing plate can be 0.1% or less, for example, it can be 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%, for example, it can be from 0% to 0.1% or from 0.01% to 0.1%. Within the above range, in the device having the above-mentioned angular relationship between the slow axes, by improving the anti-reflection effect, it is easy to provide an effect that minimizes ghosting. Regarding the short-wavelength dispersion and long-wavelength dispersion of the retardation layer, when a polarizer having the above-mentioned orthogonal transmittance is applied to the first polarizing plate, the above-mentioned effect is easily improved.

[0049] Hereinafter, a stereoscopic image display device according to an embodiment will be described.

[0050] First polarizing plate

[0051] The first polarizing plate may be located between the display section with light-emitting devices and the pancake lens assembly.

[0052] The first polarizing plate includes: a first polarizer; a first phase difference layer bonded to the display portion side of the first polarizer; and a second phase difference layer bonded to the component side of the first polarizer.

[0053] The first phase difference layer has the aforementioned short-wavelength dispersion and the aforementioned long-wavelength dispersion. The second phase difference layer has the aforementioned short-wavelength dispersion and the aforementioned long-wavelength dispersion.

[0054] In one specific embodiment, the first phase difference layer and the second phase difference layer may each have inverse wavelength dispersion.

[0055] In one specific embodiment, the in-plane phase difference of the first phase retardation layer at a wavelength of 450 nm can be 115 nm to 125 nm, for example, 119 nm to 123 nm. The in-plane phase difference of the first phase retardation layer at a wavelength of 550 nm can be 135 nm to 145 nm, for example, 139 nm to 143 nm. The in-plane phase difference of the first phase retardation layer at a wavelength of 650 nm can be 140 nm to 150 nm, for example, 142 nm to 146 nm. Within the above ranges, the aforementioned short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0056] In one specific embodiment, the in-plane phase difference of the second phase retardation layer at a wavelength of 450 nm can be 115 nm to 125 nm, for example, 119 nm to 123 nm. The in-plane phase difference of the second phase retardation layer at a wavelength of 550 nm can be 135 nm to 145 nm, for example, 139 nm to 143 nm. The in-plane phase difference of the second phase retardation layer at a wavelength of 650 nm can be 140 nm to 150 nm, for example, 142 nm to 146 nm. Within the above ranges, the aforementioned short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0057] The first phase difference layer and the second phase difference layer each have a slow axis in the in-plane direction, and as mentioned above, their slow axes are substantially orthogonal.

[0058] According to one embodiment, the slow axis of the first phasing layer can be approximately 45° relative to the reference. The slow axis of the second phasing layer can be approximately 135° relative to the reference. Within the above range, the degree of circular polarization of the light emitted by the display unit can be improved.

[0059] According to one embodiment, the slow axis of the first phasing layer can be approximately 135° relative to the reference. The slow axis of the second phasing layer can be approximately 45° relative to the reference. Within the above range, the degree of circular polarization of the light emitted by the display unit can be improved.

[0060] In this specification, "reference" refers to the absorption axis of the first polarizer in the first polarizing plate. The absorption axis of the first polarizer is the machine direction of the first polarizer. Assuming that the display unit has a long horizontal side and a short vertical side, the absorption axis of the first polarizer can be in a direction substantially the same as the horizontal side.

[0061] In one specific embodiment, the phase difference in the thickness direction of the first phase retardation layer at a wavelength of 550 nm can be from 50 nm to 80 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, for example, 55 nm to 75 nm. Within the above range, the aforementioned in-plane phase difference is easily achieved, which helps to thin the first polarizing plate.

[0062] In one specific embodiment, the biaxiality of the first phase retardation layer at a wavelength of 550 nm can be from 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, or 1.1, or for example, 0.8 to 1.0. Within the above range, the aforementioned in-plane phase retardation can be easily achieved, which helps to thin the first polarizing plate.

[0063] In one specific embodiment, the phase difference in the thickness direction of the second phase retardation layer at a wavelength of 550 nm can be 50 nm to 80 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, for example, 55 nm to 75 nm. Within the above range, the aforementioned in-plane phase difference is easily achieved, which helps to thin the first polarizing plate.

[0064] In one specific embodiment, the biaxiality of the second phase retardation layer at a wavelength of 550 nm can be from 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, or 1.1, or for example, 0.8 to 1.0. Within the above range, the aforementioned in-plane phase retardation can be easily achieved, which helps to thin the first polarizing plate.

[0065] The thickness of both the first and second phase retardation layers can be from 1 μm to 40 μm, for example, from 1.5 μm to 35 μm. Within this range, they can be used in the first polarizing plate.

[0066] As long as the first phase difference layer and the second phase difference layer can satisfy the above-mentioned wavelength dispersion and phase difference characteristics, the material is not limited.

[0067] Both the first phase difference layer and the second phase difference layer can be liquid crystal layers or non-liquid crystal layers.

[0068] In one specific embodiment, both the first retardation layer and the second retardation layer can be liquid crystal layers. For example, the liquid crystal layer may comprise a cured liquid crystal composition, wherein the liquid crystal composition comprises one or more of nematic liquid crystals, smectic liquid crystals, disk-shaped liquid crystals, and cholesteric liquid crystals. Furthermore, each of the first retardation layer and the second retardation layer may also include an alignment film to facilitate the alignment of liquid crystals within their respective liquid crystal layers. The liquid crystal layer and the alignment film described above can be readily manufactured with reference to materials well known in the art.

[0069] When the first phase difference layer and the second phase difference layer are each liquid crystal layers, the aforementioned short-wavelength dispersion and the aforementioned long-wavelength dispersion can be provided by adjusting the thickness of the liquid crystal layer, the type of liquid crystal molecules forming the liquid crystal layer, and the content of liquid crystal molecules in the liquid crystal layer.

[0070] When both the first phase difference layer and the second phase difference layer are liquid crystal layers, the first phase difference layer and the second phase difference layer may further include optical thin films. These optical thin films facilitate the formation of the liquid crystal layer without affecting the phase difference between the first phase difference layer and the second phase difference layer.

[0071] In one specific embodiment, the in-plane phase difference of the optical thin film at a wavelength of 550 nm can be less than 10 nm, for example, it can be from 0 nm to 5 nm. Within the above range, the phase difference between the first phase difference layer and the second phase difference layer will not be affected.

[0072] In one specific embodiment, the aforementioned optical film may be a film comprising an optically transparent resin. For example, the resin may comprise one or more of the following resins: cellulose-based resins including triacetyl cellulose; polyester-based resins including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; cyclic olefin copolymer (COC)-based resins; cyclic olefin polymer (COP)-based resins; polycarbonate-based resins; polyethersulfone-based resins; polysulfone-based resins; polyamide-based resins; polyimide-based resins; polyolefin-based resins; polyarylate-based resins; polyvinyl alcohol-based resins; polyvinyl chloride-based resins; polyvinylidene chloride-based resins; and acrylic-based resins.

[0073] In another specific embodiment, both the first phase difference layer and the second phase difference layer can be non-liquid crystal layers.

[0074] For example, the aforementioned non-liquid crystal layer can be a film obtained by uniaxially stretching an optically transparent resin onto an unstretched MD or TD film, or by biaxially stretching it onto an MD or TD film. The aforementioned optically transparent resin is essentially the same as described above.

[0075] When the first phase difference layer and the second phase difference layer are each non-liquid crystal layers, the aforementioned short-wavelength dispersion and the aforementioned long-wavelength dispersion can be provided by adjusting the thickness of the non-liquid crystal layer, the stretching direction and / or stretching degree during the manufacture of the non-liquid crystal layer, the type of resin used to manufacture the non-liquid crystal layer, etc.

[0076] For example, the aforementioned non-liquid crystal layer may be a coating manufactured by coating a composition containing one or more of cellulose-based compounds and polystyrene-based compounds as main components, followed by drying and / or curing.

[0077] When both the first and second phase retardation layers are non-liquid crystal layers, each of the first and second phase retardation layers may further include an optical thin film. The aforementioned optical thin film can be easily formed into the coating without affecting the phase difference between the first and second phase retardation layers. The optical thin film described above is substantially the same as described above, therefore its detailed description is omitted.

[0078] The first polarizer can convert the circular polarizer incident from the first phase difference layer into linearly polarized light, which is then emitted to the second phase difference layer.

[0079] The orthogonal transmittance of the first polarizer can be less than 0.1%, for example, it can be 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%, for example, it can be from 0% to 0.1% or from 0.01% to 0.1%. Within the above range, the anti-reflection effect is improved in the device having the above-mentioned angular relationship between the slow axes, thereby easily improving the effect of minimizing ghosting.

[0080] The polarization degree of the first polarizer can be 99% or higher, for example, 99.99% to 100%, and the single-unit transmittance (Ts) can be 42% or higher, for example, 42% to 45%. The first polarizer simultaneously satisfies the aforementioned polarization degree and single-unit transmittance, thereby significantly reducing reflectivity when stacked on the retardation layer. The aforementioned "single-unit transmittance" refers to the single-unit transmittance (Ts) measured in the visible light region, for example, at wavelengths of 400 nm to 700 nm, and can be measured using conventional methods known to those skilled in the art. The aforementioned "polarization degree" can also be measured using conventional methods known to those skilled in the art. Specifically, the polarization degree can be 99% to 99.9999%, and the transmittance can be 42% to 50%.

[0081] The light absorption axis of the first polarizer can be the stretching direction during the manufacture of the polarizer from a polyvinyl alcohol (PVA) film, for example, the machine direction (MD) of the polarizer. The first polarizer may include a PVA-based polarizer manufactured by uniaxial stretching of a PVA film. In one specific embodiment, the first polarizer can be manufactured by performing dyeing, stretching, crosslinking, and tone correction processes on the PVA film. A polarizer possessing both the aforementioned polarization degree and transmittance can be achieved by appropriately modifying the conditions of the dyeing, stretching, crosslinking, and tone correction processes.

[0082] The thickness of the first polarizer can be from 5 μm to 40 μm. Within this range, it can be used for polarizing plates.

[0083] A resin layer may also be laminated on the component side of the first polarizer.

[0084] In one specific embodiment, the resin layer can be directly formed on the component side of the first polarizer to bond to the component side of the first polarizer. "Directly formed" means that no other adhesive layer, bonding layer, and / or cured coating is formed between the first polarizer and the resin layer. The resin layer can improve ghosting removal by covering the micro-unevenness formed on the surface of the first polarizer. The resin layer can be a cured product comprising one or more compositions of thermosetting resins and UV-curable resins. The thermosetting resins and UV-curable resins can be of conventional types known to those skilled in the art. For example, the resin layer can be a cured product comprising a composition of (meth)acrylic resins.

[0085] In another specific embodiment, the laminate of the resin layer and the optical film can be formed on the component side of the first polarizer. The optical film can improve the mechanical strength of the first polarizer, and the resin layer can further improve the ghosting removal effect by covering the fine irregularities formed on the surface of the optical film. The resin layer and the optical film can be substantially the same as described above.

[0086] In one specific embodiment, the resin layer may be a hard coating, but is not limited thereto.

[0087] In one specific embodiment, the optical thin film and the resin layer may be sequentially stacked on the component side of the first polarizer.

[0088] The first polarizing plate may also have a protective layer, a functional coating, or a protective layer with a functional coating formed on the outermost side of the aforementioned component.

[0089] The aforementioned protective layer can protect the first polarizer, improve the reliability of the first polarizer plate, and enhance its mechanical strength. Even without the protective layer, it can be omitted as long as the mechanical properties of the first polarizer plate can be ensured.

[0090] According to one embodiment, the protective layer may be formed on the component side of the second phase difference layer.

[0091] The aforementioned protective layer may include one or more of optically transparent protective films or protective coatings. The protective film may comprise a film formed from one or more of the following: cellulose ester resins, including triacetyl cellulose (TAC); cyclic polyolefin resins, including amorphous cyclic polyolefins (COP); polycarbonate resins; polyester resins, including polyethylene terephthalate (PET); polyethersulfone resins; polysulfone resins; polyamide resins; polyimide resins; non-cyclic polyolefin resins; poly(meth)acrylate resins, including polymethyl methacrylate resins; polyvinyl alcohol resins; polyvinyl chloride resins; and polyvinylidene chloride resins, but is not limited thereto.

[0092] The protective coating may be formed from an active energy line curable compound and an active energy line curable resin composition containing a polymerization initiator. The active energy line curable compound may contain one or more of cationic polymerizable curable compounds, free radical polymerizable curable compounds, urethane resin, and organosilicon resins.

[0093] The protective layer can be a lag-free layer or a layer with an in-plane phase difference within a specified range. For example, the in-plane phase difference of the protective layer at a wavelength of 550 nm can be less than 5000 nm, or greater than 5000 nm, between 120 nm and 160 nm, or between 5 nm and 0 nm. Within the above range, the polarizer can be protected without affecting the effect of the phase difference layer stack.

[0094] The thickness of the protective layer can be less than 10 μm or from 5 μm to 300 μm, or less than 5 μm or from 5 μm to 200 μm. Within the above range, it can be used for polarizing plates.

[0095] The aforementioned functional coating may be formed on one or both sides of the protective layer, thereby providing additional functionality to the protective layer or the first polarizing plate. The aforementioned functional coating may include, but is not limited to, one or more of the following: a hard coating, a fingerprint-resistant layer, an anti-reflective layer, an anti-glare layer, a low-reflection layer, and an ultra-low-reflection layer.

[0096] In one specific embodiment, the aforementioned functional coating may be a low-reflection layer, an anti-reflection layer, or an anti-glare layer. The low-reflection layer, anti-reflection layer, or anti-glare layer can minimize ghosting by reflecting unwanted light that can enter from the outside or absorbing light reflected at the interface. The first polarizing plate may include one or more of the following: a low-reflection layer, an anti-reflection layer, and an anti-glare layer.

[0097] For example, the minimum reflectivity of the aforementioned low-reflection layer and anti-reflection layer can be below 3%, such as 0% to 2%. Within this range, ghosting can be minimized.

[0098] For example, the external haze of the aforementioned anti-glare layer can be 0% to 50%, and the internal haze can be 0% to 10%. Within these ranges, ghosting can be minimized. "Internal haze" refers to the value measured using the same method as for the total haze of a polarizing plate, after spraying an alcohol (e.g., ethanol) onto a glass plate with a total haze of less than 1%, attaching one side of the anti-glare layer to flatten its surface.

[0099] The "total haze" is a value measured using a standard haze meter for the anti-glare layer, such as the NHD-2000. The "external haze" can be the difference between the total haze and the internal haze of the anti-glare layer. The "haze" value measured in the visible light region, such as wavelengths from 380nm to 780nm, refers to the average value unless otherwise specified.

[0100] The aforementioned low-reflection layer, anti-reflection layer, and anti-glare layer can be easily manufactured using methods known to those skilled in the art.

[0101] Figure 2 This is a cross-sectional view of the first polarizing plate in one embodiment.

[0102] Reference Figure 2 The first polarizing plate may include a first polarizer 210; a first phase difference layer 220 bonded to the display portion (not shown) side of the first polarizer 210; and a second phase difference layer 230 and a protective layer 240 having a functional coating formed thereon bonded to the component (not shown) side of the first polarizer 210.

[0103] Although not in Figure 2 As shown, when bonding the first polarizer, the first phase difference layer, the second phase difference layer, and the protective layer, an adhesive layer or bonding layer (e.g., a pressure relief adhesive (PSA) layer) may be laminated.

[0104] Figure 3 and Figure 4 This is a diagram illustrating the axial relationship between a first polarizing plate and a phase retardation layer in an assembly according to an embodiment.

[0105] Reference Figure 3In the first polarizing plate, the light absorption axis 211 of the first polarizer 210 is approximately 45° to the slow axis 221 of the first phase difference layer 220 and approximately 135° to the slow axis 231 of the second phase difference layer 230. The slow axis 221 of the first phase difference layer 220 and the slow axis 231 of the second phase difference layer 230 can be approximately orthogonal.

[0106] Reference Figure 4 In the first polarizing plate, the light absorption axis 211 of the first polarizer 210 is approximately 135° to the slow axis 221 of the first phase difference layer 220 and approximately 45° to the slow axis 231 of the second phase difference layer 230. The slow axis 221 of the first phase difference layer 220 and the slow axis 231 of the second phase difference layer 230 can be approximately orthogonal.

[0107] According to one embodiment, the transmittance of the first polarizing plate at a wavelength of 380 nm can be 3% or less, for example, it can be 0% to 3%. Within this range, damage to the light-emitting device of the display section due to externally incident UV radiation can be prevented. Methods for achieving the above-mentioned transmittance are well known to those skilled in the art. For example, a method of including a light-absorbing agent that absorbs light at the 380 nm wavelength in any of the first polarizing plates can be considered.

[0108] Pancake Lens Assembly

[0109] The pancake lens assembly can make a stereoscopic image visible by changing the path of the light emitted from the display unit with light-emitting devices, which is incident on the first polarizing plate and then emitted from the first polarizing plate.

[0110] The pancake lens assembly may include a first lens, a phase difference layer, and a reflective polarizer arranged sequentially from the first polarizing plate.

[0111] The first lens can display stereoscopic images and improve light efficiency by transmitting incident light from the second phase retardation layer to the phase retardation layer, or by reflecting circularly polarized light from the phase retardation layer.

[0112] One of the two surfaces of the first lens is curved, thereby easily providing the aforementioned function. For example, the first lens can be a spherical concave surface, a spherical convex surface, a plane, a rotationally symmetric aspherical surface, or a free shape.

[0113] The first lens may be made of glass or plastic, and may be manufactured according to methods known in the past for pancake lenses.

[0114] The retardation layer has a slow axis in the in-plane direction, and the slow axis of the aforementioned retardation layer is substantially orthogonal to the slow axis of the aforementioned second retardation layer. If the slow axis of the aforementioned retardation layer is not substantially orthogonal to the slow axis of the aforementioned second retardation layer, although the normal optical path within the pancake lens will be magnified, the polarization state cannot be restored, which may result in the inability to form a magnified image after passing through the optical system.

[0115] Reference Figure 3 and Figure 4 The slow axis 231 of the second phase difference layer 230 can be substantially orthogonal to the slow axis 321 of the phase difference layer 320 in the assembly.

[0116] The in-plane phase difference of the phase retardation layer at a wavelength of 550 nm can be between 130 nm and 150 nm, for example, between 135 nm and 145 nm. Within this range, circularly polarized light can be easily achieved.

[0117] The retardation layer can be made of the aforementioned liquid crystal layer or non-liquid crystal layer material. Detailed explanations will be omitted.

[0118] A reflective polarizer reflects a portion of the circularly polarized light incident from the retardation layer, allowing it to re-enter the retardation layer, or transmits the remaining portion.

[0119] In one specific embodiment, the reflective polarizer can be in the form of two layers with different refractive indices stacked alternately. For example, the reflective polarizer can be a thin film stacked in the order of a high-refractive-index layer, a low-refractive-index layer, another high-refractive-index layer, and a low-refractive-index layer.

[0120] The first lens, retardation layer, and reflective polarizer in the pancake lens assembly can be purchased as commercially available products.

[0121] Figure 1 This is a schematic diagram of a stereoscopic image display device according to an embodiment.

[0122] Reference Figure 1 The stereoscopic image display device includes: a display unit 100; a first polarizing plate 200 having a first retardation layer 220, a first polarizer 210, and a second retardation layer 230; and a pancake lens assembly 300 including a first lens 310, a retardation layer 320, and a reflective polarizer 330. The light ultimately emitted through the pancake lens assembly 300 can be perceived by the user's eye 10.

[0123] Reference Figure 1 The circularly polarized light emitted from the second phase difference layer 230 passes through the first lens 310 and the phase difference layer 320, is reflected by the reflective polarizer 330, then passes through the phase difference layer 320 again and is circularly polarized, is reflected again by the first lens 310 and passes through the phase difference layer 320, and is then emitted as linearly polarized light after passing through the reflective polarizer 330.

[0124] In the pancake lens assembly, the reflective polarizer is located on the side facing the phase difference layer, that is, the outermost part of the stereoscopic image display device may also include a third polarizer.

[0125] The third polarizer absorbs linearly polarized light that has a different direction from the linearly polarized light emitted from the reflective polarizer (linearly polarized light that is substantially orthogonal to the linearly polarized light emitted from the reflective polarizer), thereby providing the effect of minimizing ghosting.

[0126] The third polarizer has an in-plane light absorption axis, which is substantially orthogonal to the light absorption axis of the first polarizer in the first polarizer plate. "Substantially orthogonal" may include 90°, or an angle ranging from -5° to +5° from 90°.

[0127] In one specific embodiment, the light absorption axis of the third polarizer may be substantially the same as the mechanical direction of the third polarizer.

[0128] The third polarizer can be manufactured using a method substantially the same as that described for the first polarizer.

[0129] The aforementioned protective layer or a protective layer with the aforementioned functional coating may also be bonded to one or both sides of the third polarizer.

[0130] Figure 5 This is a schematic diagram of a stereoscopic image display device according to an embodiment.

[0131] Reference Figure 5 It may include a pancake lens assembly 300' having a first lens 310, a retardation layer 320, a reflective polarizer 330, and a third polarizer 340, replacing Figure 1 The pancake lens assembly 300. The third polarizer 340 transmits a portion of the linearly polarized light emitted from the reflective polarizer 330 and absorbs the linearly polarized light that is substantially perpendicular to it, thereby minimizing ghosting.

[0132] Display section

[0133] The display unit may include a conventional display unit with light-emitting devices. The light-emitting devices may include one or more of organic light-emitting devices, inorganic light-emitting devices, or organic-inorganic light-emitting devices.

[0134] Next, another embodiment of the stereoscopic image display device will be described.

[0135] The aforementioned stereoscopic image display device may further include a second polarizing plate between the first polarizing plate and the pancake lens assembly.

[0136] The second polarizing plate, comprising a second polarizer, a third retardation layer, and a fourth retardation layer, will be described below. The second polarizing plate can improve optical efficiency by allowing circularly polarized light emitted from the first polarizing plate to pass through in a circularly polarized state, or by circularly polarizing light other than circularly polarized light emitted from the first polarizing plate.

[0137] The second polarizing plate includes: a second polarizer; a third phase difference layer bonded to the display portion side of the second polarizer; and a fourth phase difference layer bonded to the component side of the second polarizer.

[0138] In one specific embodiment, the third phase difference layer and the fourth phase difference layer may each have inverse wavelength dispersion.

[0139] In one specific embodiment, the short-wavelength dispersion of the third phase retardation layer and the fourth phase retardation layer is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.04. Within the above range, the brightness of the optical display device can be improved by increasing the internal transmittance.

[0140] In one specific embodiment, the in-plane phase difference of the third phase retardation layer at a wavelength of 450 nm can be 115 nm to 125 nm, for example, 119 nm to 123 nm. The in-plane phase difference of the third phase retardation layer at a wavelength of 550 nm can be 135 nm to 145 nm, for example, 139 nm to 143 nm. The in-plane phase difference of the third phase retardation layer at a wavelength of 650 nm can be 140 nm to 150 nm, for example, 142 nm to 146 nm. Within the above ranges, the aforementioned short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0141] In one specific embodiment, the in-plane phase difference of the fourth phase retardation layer at a wavelength of 450 nm can be 115 nm to 125 nm, for example, 119 nm to 123 nm. The in-plane phase difference of the fourth phase retardation layer at a wavelength of 550 nm can be 135 nm to 145 nm, for example, 139 nm to 143 nm. The in-plane phase difference of the fourth phase retardation layer at a wavelength of 650 nm can be 140 nm to 150 nm, for example, 142 nm to 146 nm. Within these ranges, the aforementioned short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0142] In one specific embodiment, the third phase difference layer may have essentially the same short-wavelength and long-wavelength dispersion as the fourth phase difference layer. This causes a change in the circular polarization degree of each wavelength, thereby avoiding the problem of inconsistent light output at different wavelengths, which could lead to an inability to provide a uniform image. "Essentially the same" includes not only a zero error but also values ​​ranging from -0.001 to +0.001.

[0143] The third and fourth phase difference layers each have a slow axis in the in-plane direction, and their slow axes are basically orthogonal.

[0144] According to one embodiment, the slow axis of the third phase retardation layer can be approximately 45° relative to the reference. The slow axis of the fourth phase retardation layer can be approximately 135° relative to the reference. Within the above range, the degree of circular polarization of the light emitted by the display unit according to wavelength can be improved.

[0145] According to another embodiment, the slow axis of the third phase retardation layer can be approximately 135° relative to the reference. The slow axis of the fourth phase retardation layer can be approximately 45° relative to the reference. Within the above range, the degree of circular polarization of the light emitted by the display unit according to wavelength can be improved.

[0146] In this specification, "reference" refers to the absorption axis of the first polarizer in the first polarizing plate. The absorption axis of the first polarizer is the machine direction of the first polarizer. Assuming the display unit has a long horizontal side and a short vertical side, the absorption axis of the first polarizer can be in a direction substantially the same as the horizontal side.

[0147] In one specific embodiment, the phase difference in the thickness direction of the third phase retardation layer at a wavelength of 550 nm can be 50 nm to 80 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, for example, 55 nm to 75 nm. Within the above range, the aforementioned in-plane phase difference is easily achieved, which helps to thin the second polarizing plate.

[0148] In one specific embodiment, the biaxiality of the third phase retardation layer at a wavelength of 550 nm can be from 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, or 1.1, for example, from 0.8 to 1.0. Within the above range, the aforementioned in-plane phase retardation can be easily achieved, which is beneficial for the thinning of the second polarizing plate.

[0149] In one specific embodiment, the phase difference in the thickness direction of the fourth phase retardation layer at a wavelength of 550 nm can be 50 nm to 80 nm, for example, 55 nm to 75 nm. Within this range, the aforementioned in-plane phase difference is easily achieved, which helps to thin the second polarizing plate.

[0150] In one specific embodiment, the biaxiality of the fourth phase retardation layer at a wavelength of 550 nm can be from 0.7 to 1.1, for example, from 0.8 to 1.0. Within this range, the aforementioned in-plane phase retardation is easily achieved, which helps to thin the second polarizing plate.

[0151] The thickness of both the third and fourth phase retardation layers can be from 1 μm to 40 μm, for example, from 1.5 μm to 35 μm. Within this range, they can be used in the first polarizing plate.

[0152] As long as the third and fourth phase retardation layers can each satisfy the aforementioned wavelength dispersion and phase difference characteristics, their materials are not limited. Both the third and fourth phase retardation layers can be liquid crystal layers or non-liquid crystal layers.

[0153] The liquid crystal layer and the non-liquid crystal layer have been described in detail in the description of the first polarizing plate, and therefore their detailed description will be omitted. Of course, the third retardation layer and the fourth retardation layer may also include the optical thin film described above.

[0154] The third and fourth phase retardation layers may each include an optical thin film. The aforementioned optical thin film can be easily formed without affecting the phase difference between the third and fourth phase retardation layers. The optical thin film is substantially the same as described above, therefore its detailed description is omitted.

[0155] The second polarizer can convert the circular polarizer incident from the third phase difference layer into linearly polarized light, which is then emitted to the fourth phase difference layer.

[0156] The second polarizer has an in-plane light absorption axis, which is substantially parallel to the light absorption axis of the first polarizer in the first polarizer plate. "Substantially parallel" means 0°, or an angle of -5 to +5° with respect to 0°.

[0157] The cross transmittance of the second polarizer can be less than 0.1%, for example, it can be from 0% to 0.1% or from 0.01% to 0.1%. Within the above range, in a device having the above-mentioned angular relationship between the slow axes, by improving the anti-reflection effect, it is easy to provide an effect that minimizes ghosting.

[0158] The polarization degree of the second polarizer can be above 99%, for example, from 99.99% to 100%, and the single-unit transmittance (Ts) can be above 42%, for example, from 42% to 45%. The polarizer simultaneously satisfies the above polarization degree and single-unit transmittance, thereby significantly reducing reflectivity when stacked in a phase difference laminate.

[0159] The light absorption axis of the second polarizer can be the stretching direction during the manufacture of the polarizer from the polyvinyl alcohol (PVA) film, such as the machine direction (MD) of the polarizer. The second polarizer may include a PVA-based polarizer manufactured by uniaxial stretching of the PVA film. In one specific embodiment, the first polarizer can be manufactured by performing dyeing, stretching, crosslinking, and tone correction processes on the PVA film. A polarizer possessing both the aforementioned polarization degree and transmittance can be achieved by appropriately modifying the conditions of the dyeing, stretching, crosslinking, and tone correction processes.

[0160] The thickness of the second polarizer can be from 5 μm to 40 μm. Within this range, it can be used in polarizing plates.

[0161] A resin layer may also be laminated on the component side of the second polarizer.

[0162] In one specific embodiment, the resin layer can be directly formed on the component side of the second polarizer to bond it to the component side of the second polarizer. "Directly formed" means that no other adhesive layer, bonding layer, and / or cured coating is formed between the second polarizer and the resin layer. The resin layer can improve ghosting removal by covering the fine irregularities formed on the surface of the second polarizer. The resin layer can be a cured product comprising one or more compositions of thermosetting resins and UV-curable resins. The thermosetting resins and UV-curable resins can be of conventional types known to those skilled in the art. For example, the resin layer can be a cured product comprising a composition of (meth)acrylic resins.

[0163] In another specific embodiment, the laminate of the resin layer and the optical film can be formed on the component side of the second polarizer. The optical film can improve the mechanical strength of the second polarizer, and the resin layer can further improve the ghosting removal effect by covering the micro-unevennesses formed on the surface of the optical film. The resin layer and the optical film can be substantially the same as described above.

[0164] In one specific embodiment, the resin layer may be a hard coating, but is not limited thereto.

[0165] The second polarizer may also have a protective layer, a functional coating, or a protective layer with a functional coating formed on the outermost side of the aforementioned component.

[0166] The aforementioned protective layer protects the second polarizer, improves the reliability of the second polarizer plate, and enhances its mechanical strength. Even without the protective layer, it can be omitted as long as the mechanical properties of the second polarizer plate can be ensured.

[0167] The aforementioned protective layer may be formed on the component side of the fourth phase difference layer.

[0168] The aforementioned protective layer may include one or more of optically transparent protective films or protective coatings. The protective film may comprise a film formed from one or more of the following: cellulose ester resins, including triacetyl cellulose (TAC); cyclic polyolefin resins, including amorphous cyclic polyolefins (COP); polycarbonate resins; polyester resins, including polyethylene terephthalate (PET); polyethersulfone resins; polysulfone resins; polyamide resins; polyimide resins; non-cyclic polyolefin resins; poly(meth)acrylate resins, including polymethyl methacrylate resins; polyvinyl alcohol resins; polyvinyl chloride resins; and polyvinylidene chloride resins, but is not limited thereto.

[0169] The protective coating may be formed from an active energy line curable compound and an active energy line curable resin composition containing a polymerization initiator. The active energy line curable compound may contain one or more of cationic polymerizable curable compounds, free radical polymerizable curable compounds, urethane resin, and organosilicon resins.

[0170] The protective layer can be a lag-free layer or a layer with an in-plane phase difference within a specified range. For example, the in-plane phase difference of the protective layer at a wavelength of 550 nm can be less than 5000 nm, or greater than 5000 nm, between 120 nm and 160 nm, or between 5 nm and 0 nm. Within the above range, the polarizer can be protected without affecting the effect of the phase difference layer stack.

[0171] The thickness of the protective layer can be less than 10 μm or from 5 μm to 300 μm, or less than 5 μm or from 5 μm to 200 μm. Within the above range, it can be used for polarizing plates.

[0172] The aforementioned functional coating may be formed on one or both sides of the protective layer, thereby providing additional functionality to the protective layer or the first polarizing plate. The aforementioned functional coating may include, but is not limited to, one or more of the following: a hard coating, a fingerprint-resistant layer, an anti-reflective layer, an anti-glare layer, a low-reflection layer, and an ultra-low-reflection layer.

[0173] In one specific embodiment, the aforementioned functional coating may be a low-reflection layer, an anti-reflection layer, or an anti-glare layer. The low-reflection layer, anti-reflection layer, or anti-glare layer can minimize ghosting by reflecting unwanted light that can enter from the outside or absorbing light reflected at the interface. The first polarizing plate may include one or more of the following: a low-reflection layer, an anti-reflection layer, and an anti-glare layer.

[0174] For example, the minimum reflectivity of the aforementioned low-reflection layer and anti-reflection layer can be below 3%, such as 0% to 2%. Within this range, ghosting can be minimized.

[0175] For example, the external haze of the aforementioned anti-glare layer can be 0% to 50%, and the internal haze can be 0% to 10%. Within these ranges, ghosting can be minimized.

[0176] The aforementioned low-reflection layer, anti-reflection layer, and anti-glare layer can be easily manufactured using methods known to those skilled in the art.

[0177] Figure 7 This is a cross-sectional view of the second polarizing plate in one embodiment.

[0178] Reference Figure 7 The second polarizing plate may include: a second polarizer 410; a third phase difference layer 420 bonded to the display portion (not shown) side of the second polarizer 410; and a fourth phase difference layer 430 and a protective layer 440 having a functional coating formed thereon bonded sequentially to the component (not shown) side of the second polarizer 410.

[0179] Although not in Figure 7 As shown, when bonding the second polarizer, the third phase retardation layer, the fourth phase retardation layer, and the protective layer, an adhesive layer or bonding layer (e.g., a pressure-reducing adhesive (PSA) layer) may be laminated.

[0180] Figures 8 to 9 This is a diagram illustrating the axial relationship between a first polarizing plate and a phase retardation layer in an assembly according to an embodiment.

[0181] Reference Figure 8 The light absorption axis 211 of the first polarizer 210 is approximately 45° to the slow axis 221 of the first phase retardation layer 220 and approximately 135° to the slow axis 231 of the second phase retardation layer 230. The slow axis 221 of the first phase retardation layer 220 is approximately orthogonal to the slow axis 231 of the second phase retardation layer 230. The absorption axis 411 of the second polarizer 410 is approximately 45° to the slow axis 421 of the third phase retardation layer 420. The absorption axis 411 of the second polarizer 410 is approximately 135° to the slow axis 431 of the fourth phase retardation layer 430. The slow axis 421 of the third phase retardation layer 420 is approximately orthogonal to the slow axis 431 of the second phase retardation layer 430.

[0182] Reference Figure 9 The light absorption axis 211 of the first polarizer 210 is approximately 135° to the slow axis 221 of the first phase retardation layer 220 and approximately 45° to the slow axis 231 of the second phase retardation layer 230. The slow axis 221 of the first phase retardation layer 220 is approximately orthogonal to the slow axis 231 of the second phase retardation layer 230. The absorption axis 411 of the second polarizer 410 is approximately 135° to the slow axis 421 of the third phase retardation layer 420. The absorption axis 411 of the second polarizer 410 is approximately 45° to the slow axis 431 of the fourth phase retardation layer 430. The slow axis 421 of the third phase retardation layer 420 is approximately orthogonal to the slow axis 431 of the second phase retardation layer 430.

[0183] According to one embodiment, the transmittance of the second polarizing plate at a wavelength of 380 nm can be 3% or less, for example, it can be 0% to 3%. Within this range, damage to the light-emitting devices of the display section due to externally incident UV radiation can be prevented. Methods for achieving the above-mentioned transmittance are well known to those skilled in the art. For example, a method of including a light-absorbing agent that absorbs light at the 380 nm wavelength in any of the first polarizing plates can be considered.

[0184] Figure 6 This is a schematic diagram of a stereoscopic image display device according to another embodiment.

[0185] Reference Figure 6 In contrast Figure 1 Between the pancake lens assembly 300 and the first polarizing plate 200, a second polarizing plate 400 having a second polarizer 410, a third phase difference layer 420, and a fourth phase difference layer 430 may also be configured.

[0186] Although not in Figure 6 As shown, a second lens may also be stacked between the second polarizing plate 400 and the first polarizing plate 200.

[0187] The second lens can amplify the light perceived by the user by amplifying the circularly polarized light emitted from the first polarizing plate.

[0188] The two surfaces of the second lens are curved, which makes it easier to provide the above-mentioned functions. For example, the second lens can be a spherical concave surface, a spherical convex surface, a plane, a rotationally symmetric aspherical surface, or a free shape.

[0189] The second lens may be made of glass or plastic, and may be manufactured according to methods known in the past for pancake lenses.

[0190] Preferred Implementation

[0191] The structure and function of the present invention will now be described in more detail through preferred embodiments. However, this is merely presented as a preferred example of the present invention and should not be construed as limiting the present invention in any way.

[0192] Example 1

[0193] A polyvinyl alcohol-based film (Kuraray Corporation, Japan, thickness before stretching: 60 μm) was dyed and adsorbed in an iodine aqueous solution at 55°C, and then stretched 6 times along the MD of the film to produce a first polarizer (transmittance: 44%, orthogonal transmittance: 0.07%, thickness: 10 μm).

[0194] A triacetyl cellulose film is bonded to one side of a first polarizer, and a composition containing an acrylic resin is coated onto one side of the triacetyl cellulose film and then cured, thereby creating a laminate formed in the order of the first polarizer, the triacetyl cellulose film, and the resin layer.

[0195] A phase retardation layer is bonded to both sides of the aforementioned laminate to create a first polarizing plate, wherein the layers are bonded in the following order: first phase retardation layer (liquid crystal layer) - first polarizer - triacetyl cellulose film - resin layer - second phase retardation layer (liquid crystal layer). The first and second phase retardation layers each possess inverse wavelength dispersion, short-wavelength dispersion, and long-wavelength dispersion, as shown in Table 1 below. Both the first and second phase retardation layers are manufactured using nematic liquid crystal.

[0196] The aforementioned first polarizing plate, display section with OLED device, and pancake lens assembly are manufactured in the manner described above. Figure 1 The configuration shown is used to manufacture modules for stereoscopic image display devices.

[0197] At this point, the slow axis of the second phase retardation layer in the first polarizing plate is at 90° to the slow axis of the phase retardation layer in the pancake lens assembly.

[0198] The light absorption axis of the polarizer in the first polarizer plate is at 45° to the slow axis of the first phase reversal layer, and the slow axis of the first phase reversal layer is at 90° to the slow axis of the second phase reversal layer.

[0199] Example 2

[0200] Except for changing the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer in Example 1 as shown in Table 1 below, the module for the stereoscopic image display device is manufactured by the same method as in Example 1.

[0201] Example 3

[0202] A polyvinyl alcohol-based film (Kuraray Corporation, Japan, thickness before stretching: 60 μm) was dyed and adsorbed in an iodine aqueous solution at 55°C, and then stretched 6 times along the MD of the film to produce a second polarizer (transmittance: 44%, orthogonal transmittance: 0.07%, thickness: 10 μm).

[0203] A triacetyl cellulose film is laminated to one side of a second polarizer, and a composition containing an acrylic resin is coated onto one side of the triacetyl cellulose film and then cured, thereby creating a laminate formed in the order of the second polarizer, the triacetyl cellulose film, and the resin layer.

[0204] Phase retardation layers are bonded to both sides of the fabricated laminate, thereby creating a second polarizing plate with the following sequence: third phase retardation layer - second polarizer - triacetyl cellulose film - resin layer - fourth phase retardation layer. The third and fourth phase retardation layers each possess inverse wavelength dispersion, short-wavelength dispersion, and long-wavelength dispersion, as shown in Table 1 below. Both the third and fourth phase retardation layers are manufactured using nematic liquid crystal.

[0205] Except that the second polarizing plate described above is disposed between the first polarizing plate and the pancake lens assembly in Embodiment 1, the module is manufactured by the same method as in Embodiment 1.

[0206] Examples 4 to 5

[0207] Except for changing the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer in Example 3 as shown in Table 1 below, the module for the stereoscopic image display device is manufactured by the same method as in Example 3.

[0208] Comparative Example 1 and Comparative Example 2

[0209] Except for changing the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer in Example 1 as shown in Table 1 below, the module for the stereoscopic image display device is manufactured by the same method as in Example 1.

[0210] Comparative Example 3

[0211] Except that the slow axis of the second phase retardation layer in the first polarizing plate is at 45° to the slow axis of the phase retardation layer in the pancake lens assembly, the module for the stereoscopic image display device is manufactured by the same method as in Example 1.

[0212] The following evaluations were conducted on the modules for the stereoscopic image display apparatus in the embodiments and comparative examples, and the results are shown in Table 1.

[0213] * Resolution (Modulation Transfer Function (MTF)) (unit: %): Evaluated using Radiant's ProMetric device by measuring the luminance ratio within the image, i.e., the difference between bright and dark areas (contrast ratio). A higher measurement value indicates higher resolution.

[0214] MTF calculation formula = (Maximum contrast ratio - Minimum contrast ratio) / (Maximum contrast ratio + Minimum contrast ratio) × 100

[0215] * Light leakage: Observe diagonal light leakage with the naked eye in a dark room. If it is not visible to the naked eye, mark it as "none" and evaluate it as "weak", "medium" or "strong" according to the visible intensity.

[0216] Table 1

[0217]

[0218] * Angle: The angle formed by the slow axis of the second phase refraction layer and the slow axis of the phase refraction layer in the pancake lens assembly.

[0219] As shown in Table 1 above, the stereoscopic image display device of the embodiment can eliminate light leakage at the edge in the viewer's side view and has high resolution.

[0220] Simple variations or modifications of the present invention can be readily implemented by those skilled in the art, and these variations or modifications are considered to be included within the scope of the present invention.

Claims

1. A stereoscopic image display device, comprising at least: It includes a display unit with light-emitting devices, a first polarizing plate, and a pancake lens assembly. The first polarizing plate includes: a first polarizer; a first retardation layer bonded to the display portion side of the first polarizer; and a second retardation layer bonded to the component side of the first polarizer. The pancake lens assembly includes a phase retardation layer. The slow axis of the second retardation layer is substantially orthogonal to the slow axis of the retardation layer in the pancake lens assembly. The short-wavelength dispersion of the first phase difference layer and the second phase difference layer is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.

04.

2. The stereoscopic image display device according to claim 1, wherein, The first polarizing plate is located between the display section having the light-emitting device and the pancake lens assembly.

3. The stereoscopic image display device according to claim 1, wherein, The slow axis of the first phase difference layer is substantially orthogonal to the slow axis of the second phase difference layer.

4. The stereoscopic image display device according to claim 1, wherein, The cross transmittance of the first polarizer is less than 0.1%.

5. The stereoscopic image display device according to claim 1, wherein, The first polarizer is further laminated with a resin layer on the component side.

6. The stereoscopic image display device according to claim 5, wherein, The resin layer is a hard coating.

7. The stereoscopic image display device according to claim 1, wherein, The display section is composed of a long horizontal side and a short vertical side, and the absorption axis of the first polarizer is in the same direction as the horizontal side.

8. The stereoscopic image display device according to claim 1, wherein, A second polarizing plate is also included between the first polarizing plate and the pancake lens assembly.

9. The stereoscopic image display device according to claim 8, wherein, The second polarizing plate includes: a second polarizer; a third phase retardation layer bonded to the display side of the second polarizer; and a fourth phase retardation layer bonded to the component side of the second polarizer.

10. The stereoscopic image display device according to claim 9, wherein, The short-wavelength dispersion of the third phase difference layer and the fourth phase difference layer is 0.84 to 0.88, and the long-wavelength dispersion is 1.01 to 1.

04.

11. The stereoscopic image display device according to claim 9, wherein, The slow axis of the third phase difference layer is approximately 45° relative to the absorption axis of the first polarizer, and the slow axis of the fourth phase difference layer is approximately 135° relative to the absorption axis of the first polarizer.

12. The stereoscopic image display device according to claim 9, wherein, The light absorption axis of the second polarizer is substantially parallel to the light absorption axis of the first polarizer.

13. The stereoscopic image display device according to claim 9, wherein, The cross transmittance of the second polarizer is less than 0.1%.

14. The stereoscopic image display device according to claim 1, wherein, The reflective polarizer also includes a third polarizer on the side facing the phase difference layer.

15. The stereoscopic image display device according to claim 14, wherein, The light absorption axis of the third polarizer is substantially orthogonal to the light absorption axis of the first polarizer.

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