Stereoscopic image display apparatus

Abstract

Provided is a stereoscopic image display apparatus, comprising: a display unit having a light emitting device; a first polarizing plate; and a pancake lens assembly, wherein the first polarizing plate comprises: a first polarizer; a first phase difference layer bonded to the display unit side of the first polarizer; and a second phase difference layer bonded to the assembly side of the first polarizer, the pancake lens assembly comprises a phase difference layer, a slow axis of the second phase difference layer is substantially perpendicular to a slow axis of the phase difference layer in the pancake lens assembly, and a short-wavelength dispersion is 0.84 to 0.88, and a long-wavelength dispersion is 1.01 to 1.04.

Description

3D image display device

[0001] It relates to a three-dimensional image display device.

[0002] Recently, interest has been growing in display devices that display three-dimensional images, moving beyond display devices that simply display a flat screen.

[0003] Devices displaying stereoscopic images are known to utilize pancake lenses. However, the stereoscopic images provided by these devices have limited resolution. Resolution, in this context, refers to the difference in contrast between bright and dark areas within the device's screen.

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

[0005] The purpose is to provide a three-dimensional image display device with high resolution, which allows the user to perceive the same light output according to wavelength, eliminates light leakage occurring at the edge of the viewing angle from the viewer's perspective, and has the same light output level according to wavelength.

[0006] According to one embodiment, a three-dimensional image display device is provided.

[0007] The stereoscopic image display device comprises at least a display unit having a light-emitting element, a first polarizing plate, and a pancake lens assembly, wherein the first polarizing plate comprises a first polarizer; a first phase difference layer bonded to the display unit side of the first polarizer; and a second phase difference layer bonded to the assembly side of the first polarizer, wherein the pancake lens assembly comprises a phase difference layer, and a slow axis of the second phase difference layer is substantially orthogonal to a slow axis of the phase difference layer in the pancake lens assembly, and the short wavelength dispersion of each 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.

[0008] Since the level of light output is the same according to wavelength, the user perceives the same light output according to wavelength, light leakage occurring at the edge of the field of view is eliminated from the viewer, and resolution can be high.

[0009] Figure 1 is a conceptual diagram of a three-dimensional image display device according to one embodiment.

[0010] Figure 2 is a cross-sectional view of a first polarizing plate of one embodiment.

[0011] Figures 3 and 4 illustrate the axial relationship between the first polarizing plate of one embodiment and the phase difference layer during assembly.

[0012] Figure 5 is a conceptual diagram of a stereoscopic image display device of another embodiment.

[0013] Figure 6 is a conceptual diagram of a stereoscopic image display device of another embodiment.

[0014] Fig. 7 is a cross-sectional view of a second polarizing plate of one embodiment.

[0015] Figures 8 and 9 illustrate the axial relationship between the first polarizing plate, the second polarizing plate, and the phase difference layer in the assembly of one embodiment.

[0016] Hereinafter, embodiments of the present application will be described in more detail with reference to the attached drawings. However, the technology disclosed in the present application is not limited to the embodiments described herein and may be embodied in other forms. However, the embodiments introduced herein are provided so that the disclosed content can be thorough and complete and so that the spirit of the present application can be sufficiently conveyed to those skilled in the art. In order to clearly express the components of each device in the drawings, the sizes of the components, such as width and thickness, are somewhat enlarged. However, the sizes of the components, such as width and thickness, in the present invention do not limit the scope of the present invention. The same reference numerals in multiple drawings indicate substantially the same components.

[0017] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0018] In this specification, "upper" and "lower" are defined based on the drawing, and depending on the perspective, "upper" may be changed to "lower" and "lower" may be changed to "upper", and reference to "on" or "on" may include not only directly on but also cases where another structure is interposed in between. On the other hand, reference to "directly on" or "directly above" or "directly formed" indicates cases where there is no intervening other structure such as an intermediate body.

[0019] In this specification, the “in-plane phase difference (Re)” is expressed by the following formula A, the “thickness direction phase difference (Rth)” is expressed by the following formula B, and the “degree of biaxiality (NZ)” is expressed by the following formula C:

[0020] [Formula A]

[0021] Re = (nx - ny) xd

[0022] [Formula B]

[0023] Rth = ((nx + ny) / 2 - nz) xd

[0024] [Formula C]

[0025] NZ = (nx - nz) / (nx - ny)

[0026] (In the above formulas A to C, nx, ny, and nz are the refractive indices in the slow axis direction, the fast axis direction, and the thickness direction of the optical element, respectively, at the measurement wavelength, and d is the thickness of the optical element (unit: nm).)

[0027] The above 'ground axis' refers to the axis with the highest refractive index in the direction within the plane, and the 'true axis' refers to the axis with the lowest refractive index in the direction within the plane.

[0028] In the above formulas A to C, the “optical element” may be a first phase difference layer, a second phase difference layer, a protective layer, or a phase difference layer stack. In the above formulas A to C, the “measurement wavelength” may mean a wavelength of 450 nm, 550 nm, or 650 nm.

[0029] 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 in-plane phase differences at wavelengths of 450 nm, 550 nm, and 650 nm, respectively, of the phase difference layer.

[0030] In this specification, 'orthogonal transmittance (Tc)' is the average value of values ​​measured perpendicular to the polarizer and in a polarized state at a wavelength of 380 to 780 nm.

[0031] When describing a numerical range in this specification, “X to Y” means X or more and Y or less (X≤ and ≤Y).

[0032] A stereoscopic image display device according to one embodiment is capable of implementing artificial reality or is related to a device implementing artificial reality. Artificial reality is a form of reality that has been manipulated 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.

[0033] A stereoscopic image display device according to one embodiment is assumed to include a pancake lens assembly. The pancake lens assembly can allow a user to perceive artificial reality by controlling the optical path of light emitted from a display unit having a light-emitting element. In the stereoscopic image display device, a first polarizing plate is provided between the display unit and the pancake lens assembly.

[0034] The first polarizing plate has a first phase difference layer and a second phase difference layer, and the short wavelength dispersion and the long wavelength dispersion of each of the first phase difference layer and the second phase difference layer are adjusted to the ranges described below, and the slow axis of the second phase difference layer and the slow axis of the phase difference layer in the pancake lens assembly are substantially orthogonal. Accordingly, the stereoscopic image display device has the same degree of light output according to wavelength, so that the user recognizes the same light output according to wavelength, and can eliminate light leakage occurring at the edge within the viewing angle on the viewer side and increase the resolution. Here, 'resolution' means the difference in contrast ratio between a bright area and a dark area within the screen of the device. The higher the resolution, the more likely it is to provide a screen without a ghost image.

[0035] A stereoscopic image display device according to one embodiment comprises at least a display unit having a light-emitting element, a first polarizing plate, and a pancake lens assembly, wherein the first polarizing plate comprises a first polarizer; a first phase difference layer bonded to the display unit side of the first polarizer; and a second phase difference layer bonded to the assembly side of the first polarizer, wherein the pancake lens assembly comprises a phase difference layer, and a slow axis of the second phase difference layer is substantially orthogonal to a slow axis of the phase difference layer in the pancake lens assembly, and the first phase difference layer and the second phase difference layer each have a short wavelength dispersion of 0.84 to 0.88 and a long wavelength dispersion of 1.01 to 1.04.

[0036] The ground axis of the second phase difference layer is substantially orthogonal to the ground axis of the phase difference layer in the pancake lens assembly. Here, "substantially orthogonal" means an angle within the range of -5 to +5° from 90°, preferably 90°. This can provide the effect of eliminating ghost images and blocking light leaked due to internal scattering.

[0037] The short wavelength dispersion is 0.84 to 0.88, and the long wavelength dispersion is 1.01 to 1.04. In the present invention, two phase difference layers are arranged on both sides of the polarizer in the first polarizing plate, and the short wavelength dispersion and the long wavelength dispersion of the two phase difference layers are adjusted while making the slow axis of the second phase difference layer substantially orthogonal to the slow axis of the phase difference layer in the pancake lens assembly. Through this, the stereoscopic image display device has the effect of increasing the resolution on the screen on the viewer side and significantly eliminating light leakage occurring at the edge.

[0038] If the above short-wavelength dispersion is less than 0.84, there may be a problem in which short-wavelength light leaks out and a blue ghost image may be recognized.

[0039] If the above short-wavelength dispersion exceeds 0.88, there may be a problem in which long-wavelength light leaks out and a red ghost image may be recognized.

[0040] If the above long wavelength dispersion is less than 1.01, there may be a problem in which long wavelength light leaks out and a red ghost image may be recognized.

[0041] If the above long-wavelength dispersion exceeds 1.04, there may be a problem in which short-wavelength light leaks out and a blue ghost image may be recognized.

[0042] In one embodiment, the short wavelength dispersion may be 0.85 to 0.87, and the long wavelength dispersion may be 1.02 to 1.03.

[0043] In one specific example, the first phase difference layer may have substantially the same short-wavelength dispersion as the second phase difference layer. The first phase difference layer may have substantially the same long-wavelength dispersion as the second phase difference layer. This allows the degree of circular polarization to vary by wavelength, thereby eliminating the problem of providing a uniform image due to differences in light output by wavelength in the user's perception. Here, "substantially the same" includes not only a case where the error is 0, but also a value within the range of -0.001 to +0.001 from 0.

[0044] According to one embodiment, the slow axis of the first phase difference layer may be substantially orthogonal to the slow axis of the second phase difference layer. Here, 'substantially orthogonal' means an angle within a range of -5 to +5° from 90°, preferably 90°. This can help reduce light loss and equalize the output for each wavelength by allowing light from the display unit to be circularly polarized to substantially the same degree when the light is circularly polarized while passing through the first phase difference layer and then circularly polarized again while sequentially passing through the polarizer and the second phase difference layer.

[0045] According to one implementation, the polarizer of the first polarizing plate may have an orthogonal transmittance of 0.1% or less, for example, 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1%, for example, 0 to 0.1%, 0.01 to 0.1%. In the above range, it may be easy to provide an effect of minimizing ghost images by increasing an anti-reflection effect in a device having an angle relationship between the above-described ground axes. The short-wavelength dispersion and long-wavelength dispersion of the above-described phase difference layer may be easy to increase the above-described effect when applying a polarizer having the above-described orthogonal transmittance to the first polarizing plate.

[0046] Below, a three-dimensional image display device according to an embodiment is described in detail.

[0047] first polarizing plate

[0048] The first polarizing plate may be positioned between the display portion having the light-emitting element and the pancake lens assembly.

[0049] 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 assembly side of the first polarizer.

[0050] The first phase difference layer has the short wavelength dispersion and the long wavelength dispersion described above. The second phase difference layer has the short wavelength dispersion and the long wavelength dispersion described above.

[0051] In one specific example, the first phase difference layer and the second phase difference layer may each have reverse wavelength dispersion.

[0052] In one specific example, the first phase difference layer can have an in-plane retardation of 115 to 125 nm, for example, 119 to 123 nm, at a wavelength of 450 nm. The first phase difference layer can have an in-plane retardation of 135 to 145 nm, for example, 139 to 143 nm, at a wavelength of 550 nm. The first phase difference layer can have an in-plane retardation of 140 to 150 nm, for example, 142 to 146 nm, at a wavelength of 650 nm. Within the above ranges, the above-described short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0053] In one specific example, the second phase difference layer may have an in-plane retardation of 115 to 125 nm, for example, 119 to 123 nm, at a wavelength of 450 nm. The second phase difference layer may have an in-plane retardation of 135 to 145 nm, for example, 139 to 143 nm, at a wavelength of 550 nm. The second phase difference layer may have an in-plane retardation of 140 to 150 nm, for example, 142 to 146 nm, at a wavelength of 650 nm. In the above ranges, the above-described short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0054] The first phase difference layer and the second phase difference layer each have a ground axis in the in-plane direction, and as described above, the ground axes of these two are substantially orthogonal.

[0055] According to one embodiment, the ground axis of the first phase difference layer may be substantially 45° with respect to the reference. The ground axis of the second phase difference layer may be substantially 135° with respect to the reference. Within the above range, the degree of circular polarization of light emitted from the display unit may be increased.

[0056] According to one embodiment, the ground axis of the first phase difference layer may be substantially 135° with respect to the reference. The ground axis of the second phase difference layer may be substantially 45° with respect to the reference. Within the above range, the degree of circular polarization of light emitted from the display unit may be increased.

[0057] In this specification, the term "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. When the display unit has a horizontal direction, which is the long side, and a vertical direction, which is the short side, the absorption axis of the first polarizer may be substantially in the same direction as the horizontal direction.

[0058] In one specific example, the first phase difference layer may have a thickness-wise phase difference of 50 to 80 nm, for example, 50, 55, 60, 65, 70, 75, 80 nm, for example, 55 to 75 nm, at a wavelength of 550 nm. In this range, the above-described in-plane phase difference can be easily achieved, and may help to thin the first polarizing plate.

[0059] In one specific example, the first phase difference layer may have a degree of biaxiality of 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, 1.1, for example, 0.8 to 1.0, at a wavelength of 550 nm. In this range, the above-described in-plane phase difference can be easily achieved, and it can help to thin the first polarizing plate.

[0060] In one specific example, the second phase difference layer may have a thickness-wise phase difference of 50 to 80 nm at a wavelength of 550 nm, for example, 50, 55, 60, 65, 70, 75, 80 nm, for example, 55 to 75 nm. In this range, the above-described in-plane phase difference can be easily achieved, and may help to thin the first polarizing plate.

[0061] In one specific example, the second phase difference layer may have a degree of biaxiality of 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, 1.1, for example, 0.8 to 1.0, at a wavelength of 550 nm. In this range, the above-described in-plane phase difference can be easily achieved, and it can help to thin the first polarizing plate.

[0062] The first phase difference layer and the second phase difference layer may each have a thickness of 1 to 40 μm, for example, 1.5 to 35 μm. Within the above range, they can be used in the first polarizing plate.

[0063] There is no limitation on the materials of the first phase difference layer and the second phase difference layer as long as they can satisfy the wavelength dispersion and phase difference characteristics described above.

[0064] The first phase difference layer and the second phase difference layer may each be a liquid crystal layer or a non-liquid crystal layer.

[0065] In one specific example, the first phase difference layer and the second phase difference layer may each be a liquid crystal layer. For example, the liquid crystal layer may include a cured product of a liquid crystal composition including at least one of a nematic liquid crystal, a smectic liquid crystal, a discotic liquid crystal, and a cholesteric liquid crystal. In addition, the first phase difference layer and the second phase difference layer may each further include an alignment film to facilitate alignment of the liquid crystal within the liquid crystal layer. The above-described liquid crystal layer and the above-described alignment film can be easily manufactured by referring to information known to those skilled in the art.

[0066] When the first phase difference layer and the second phase difference layer are each liquid crystal layers, the short wavelength dispersion and the long wavelength dispersion described above can be provided by controlling the thickness of the liquid crystal layer, the type of liquid crystal molecules forming the liquid crystal layer, the content of liquid crystal molecules in the liquid crystal layer, etc.

[0067] When the first phase difference layer and the second phase difference layer are each liquid crystal layers, the first phase difference layer and the second phase difference layer may further include an optical film. The optical film can facilitate the formation of the liquid crystal layer without affecting the phase difference of the first phase difference layer and the second phase difference layer.

[0068] In one specific example, the optical film may have an in-plane retardation of 10 nm or less, for example, 0 to 5 nm, at a wavelength of 550 nm. In this range, the retardation of the first retardation layer and the second retardation layer may not be affected.

[0069] In one specific example, the optical film may be a film including an optically transparent resin. For example, the resin may include at least one of a cellulose-based resin including triacetyl cellulose, a polyester-based resin including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, a cyclic olefin polymer (COC)-based resin, a cyclic olefin polymer (COP)-based resin, a polycarbonate-based resin, a polyethersulfone-based resin, a polysulfone-based resin, a polyamide-based resin, a polyimide-based resin, a polyolefin-based resin, a polyarylate-based resin, a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, a polyvinylidene chloride-based resin, and an acrylic-based resin.

[0070] In another specific embodiment, the first phase difference layer and the second phase difference layer can each be a non-liquid crystal layer.

[0071] For example, the non-liquid crystal layer may be a film that is uniaxially stretched in MD or TD of an optically transparent resin that is not stretched, or a film that is biaxially stretched in MD and TD. The optically transparent resin is substantially the same as described above.

[0072] When the first phase difference layer and the second phase difference layer are each non-liquid crystal layers, the short wavelength dispersion and the long wavelength dispersion described above can be provided by controlling 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.

[0073] For example, the non-liquid crystal layer may be a coating layer manufactured by coating a composition including at least one of a cellulose-based compound and a polystyrene-based compound as a main component and then drying and / or curing the coating.

[0074] When the first phase difference layer and the second phase difference layer are each non-liquid crystal layers, the first phase difference layer and the second phase difference layer may further include an optical film. The optical film can facilitate the formation of the coating layer without affecting the phase difference of the first phase difference layer and the second phase difference layer. Since the optical film is substantially the same as described above, its description is omitted.

[0075] The first polarizer can linearly polarize the circular polarizing plate incident from the first phase difference layer and output it to the second phase difference layer.

[0076] The first polarizer may have an orthogonal transmittance of 0.1% or less, for example, 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1%, for example, 0 to 0.1%, 0.01 to 0.1%. In the above range, it may be easy to provide an effect of minimizing ghost images by increasing an anti-reflection effect in a device having an angle relationship between the above-described ground axes.

[0077] The first polarizer may have a degree of polarization of 99% or more, for example, 99.99% to 100%, and a single-light transmittance (Ts) of 42% or more, for example, 42 to 45%. Since the first polarizer satisfies both the degree of polarization and the single-light transmittance, the reflectance may be significantly reduced when laminated on the phase difference layer. The "single-light transmittance" refers to the single-light transmittance (Ts) measured in the visible light region, for example, at a wavelength of 400 nm to 700 nm, and may be measured by a conventional method known to those skilled in the art. The "degree of polarization" may be measured by a conventional method known to those skilled in the art. Specifically, the degree of polarization may be 99% to 99.9999%, and the light transmittance may be 42% to 50%.

[0078] The light absorption axis of the first polarizer may be the stretching direction, for example, the machine direction (MD) of the polarizer, when manufacturing the polarizer from the polyvinyl alcohol-based film. The first polarizer may include a polyvinyl alcohol-based polarizer manufactured by uniaxially stretching the polyvinyl alcohol-based film. In one specific example, the first polarizer may be manufactured by dyeing, stretching, crosslinking, and color correction processes of the polyvinyl alcohol-based film. A polarizer having both the above-described polarization degree and light transmittance can be achieved by appropriately changing the conditions in the above-described dyeing, stretching, crosslinking, and color correction processes.

[0079] The first polarizer may have a thickness of 5 μm to 40 μm. Within this range, it may be used in a polarizing plate.

[0080] A resin layer may be further laminated on the assembly side of the first polarizer.

[0081] In one specific example, the resin layer may be directly formed on the assembly side of the first polarizer and bonded to the assembly side of the first polarizer. Here, “directly formed” means that no other adhesive layer, bonding layer, and / or curable coating layer is formed between the first polarizer and the resin layer. The resin layer may further enhance the ghost image removal effect by covering fine irregularities formed on the surface of the first polarizer. The resin layer may be a cured product of a composition including at least one of a thermosetting resin and an ultraviolet-curable resin. The thermosetting resin and the ultraviolet-curable resin may be selected from general types known to those skilled in the art. For example, the resin layer may be a cured product of a composition including a (meth)acrylic resin.

[0082] In another specific embodiment, a laminate of the resin layer and the optical film may be formed on the assembly side of the first polarizer. The optical film may increase the mechanical strength of the first polarizer, and the resin layer may further enhance the ghost image removal effect by covering the fine irregularities formed on the surface of the optical film. The resin layer and the optical film may be substantially the same as described above.

[0083] In one specific example, the resin layer may be, but is not limited to, a hard coating layer.

[0084] In one specific example, the optical film and the resin layer may be sequentially laminated on the assembly side of the first polarizer.

[0085] The first polarizing plate may further have a protective layer, a functional coating layer, or a protective layer formed with a functional coating layer formed on the outermost side of the assembly.

[0086] The above protective layer can protect the first polarizer, increase the reliability of the first polarizing plate, and increase the mechanical strength of the first polarizing plate. If the mechanical properties of the first polarizing plate can be secured even without the protective layer, the protective layer may be omitted.

[0087] According to one embodiment, the protective layer may be formed on the assembly side of the second phase difference layer.

[0088] The protective layer may include at least one of an optically transparent protective film or a protective coating layer. The protective film may include a film formed of at least one of a cellulose ester resin including triacetyl cellulose (TAC) or the like, a cyclic polyolefin resin including amorphous cyclic polyolefin (COP) or the like, a polycarbonate resin, a polyester resin including polyethylene terephthalate (PET) or the like, a polyethersulfone resin, a polysulfone resin, a polyamide resin, a polyimide resin, an acyclic-polyolefin resin, a poly(meth)acrylate resin including polymethyl methacrylate resin, a polyvinyl alcohol resin, a polyvinyl chloride resin, and a polyvinylidene chloride resin, but is not limited thereto.

[0089] The protective coating layer can be formed from an active energy ray-curable resin composition containing an active energy ray-curable compound and a polymerization initiator. The active energy ray-curable compound can include at least one of a cationic polymerizable curable compound, a radical polymerizable curable compound, a urethane resin, and a silicone resin.

[0090] The protective layer may be a phase-free layer or may have an in-plane phase difference of a predetermined range. For example, the protective layer may have an in-plane phase difference of less than 5000 nm, or greater than 5000 nm, or 120 to 160 nm, or 5 to 0 nm at a wavelength of 550 nm. Within the above range, the polarizing plate can be protected without affecting the effect of the phase-differentiation layer stack.

[0091] The protective layer may have a thickness of 10 μm or less, or 5 μm to 300 μm, or 5 μm or less, or 5 μm to 200 μm. In the above range, it may be used in a polarizing plate.

[0092] The functional coating layer may be formed on one or both sides of the protective layer to provide additional functions to the protective layer or the first polarizing plate. The functional coating layer may include, but is not limited to, one or more of a hard coating layer, an anti-fingerprint layer, an anti-reflection layer, an anti-glare layer, a low-reflection layer, and an ultra-low-reflection layer.

[0093] In one specific example, the functional coating layer may be a low-reflection layer, an anti-reflection layer, or an anti-glare layer. The low-reflection layer, the anti-reflection layer, or the anti-glare layer may minimize ghost images by reflecting unnecessary light that may enter from the outside or absorbing light reflected at the interface. The first polarizing plate may include at least one of a low-reflection layer, an anti-reflection layer, and an anti-glare layer.

[0094] For example, the low-reflection layer and the anti-reflection layer may each have a minimum reflectivity of 3% or less, for example, 0 to 2%. Within the above range, ghost images can be minimized.

[0095] For example, the anti-glare layer may have an external haze of 0 to 50% and an internal haze of 0 to 10%. In the above range, ghost images can be minimized. Here, the 'internal haze' is a value measured in the same way as the overall haze of the polarizing plate after spraying alcohol (e.g., ethanol) on a glass plate with an overall haze of less than 1% and then laminating the anti-glare layer side to smooth out the unevenness of the surface of the anti-glare layer.

[0096] Here, "total haze" refers to the value measured by a conventional haze meter of the antiglare layer, such as the NHD-2000. Here, "external haze" refers to the difference between the total haze of the antiglare layer and the internal haze. Here, "haze" refers to the value measured in the visible light range, such as a wavelength of 380 nm to 780 nm, and unless otherwise specified, refers to the average value.

[0097] The above low-reflection layer, anti-reflection layer, and anti-glare layer can be easily manufactured by methods known to those skilled in the art.

[0098] Figure 2 is a cross-sectional view of a first polarizing plate of one embodiment.

[0099] Referring to FIG. 2, the first polarizing plate may include a first polarizer 210; a first phase difference layer 220 bonded to a display portion (not shown) side of the first polarizer 210; and a second phase difference layer 230 sequentially bonded to an assembly (not shown) side of the first polarizer 210, and a protective layer 240 having a functional coating layer formed thereon.

[0100] Although not shown in FIG. 2, when bonding the first polarizer, the first phase difference layer, the second phase difference layer, and the protective layer, an adhesive layer or a pressure-sensitive adhesive layer (e.g., a pressure-sensitive adhesive (PSA) layer) may be laminated.

[0101] Figures 3 and 4 illustrate the axial relationship between the first polarizing plate of one embodiment and the phase difference layer during assembly.

[0102] Referring to FIG. 3, in the first polarizing plate, the light absorption axis 211 of the first polarizer 210 forms a substantially 45° angle with the slow axis 221 of the first phase difference layer 220, and forms a substantially 135° angle with the slow axis 231 of the second phase difference layer 230, and 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 substantially orthogonal.

[0103] Referring to FIG. 4, in the first polarizing plate, the light absorption axis 211 of the first polarizer 210 forms a substantially 135° angle with the slow axis 221 of the first phase difference layer 220, and forms a substantially 45° angle with the slow axis 231 of the second phase difference layer 230, and 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 substantially orthogonal.

[0104] According to one embodiment, the first polarizing plate may have a light transmittance of 3% or less, for example, 0 to 3%, at a wavelength of 380 nm. Within this range, the light-emitting element of the display unit may be prevented from being damaged by UV rays incident from the outside. Methods for achieving this light transmittance are known to those skilled in the art. For example, a method of including a light absorbing agent that absorbs light at a wavelength of 380 nm in any one of the first polarizing plates may be considered.

[0105] Pancake Lens Assembly

[0106] The pancake lens assembly can allow a three-dimensional image to be viewed by changing the path of light emitted from the first polarizing plate after the light from the display unit having the light emitting element is incident on the first polarizing plate.

[0107] The pancake lens assembly may include a first lens, a phase difference layer, and a reflective polarizer sequentially arranged from the first polarizing plate.

[0108] The first lens transmits light incident from the second phase difference layer to the phase difference layer or reflects circularly polarized light from the phase difference layer, thereby displaying a three-dimensional image and increasing light efficiency.

[0109] The first lens may be configured to provide the aforementioned function by having one of its two surfaces curved. For example, the first lens may be a spherically concave surface, a spherically convex surface, a plane surface, a rotationally symmetric aspherical surface, or a free-form shape.

[0110] The first lens may be formed of glass or plastic, and the first lens may be manufactured according to methods known in the art for making pancake lenses.

[0111] The phase difference layer has a slow axis in the in-plane direction, and the slow axis of the phase difference layer is substantially orthogonal to the slow axis of the second phase difference layer. If the slow axis of the phase difference layer is not substantially orthogonal to the slow axis of the second phase difference layer, the image is magnified through the normal optical path within the pancake lens, but there may be a problem in that the polarization state is not restored and an image cannot be created that is magnified by passing through the optical system.

[0112] Referring to FIGS. 3 and 4, the ground axis 231 of the second phase difference layer 230 can be substantially orthogonal to the ground axis 321 of the phase difference layer 320 during assembly.

[0113] The phase difference layer may have an in-plane phase difference of 130 to 150 nm, for example, 135 to 145 nm, at a wavelength of 550 nm. Within this range, circular polarization may be easily achieved.

[0114] The phase difference layer can be formed of the liquid crystal layer or non-liquid crystal layer material described above. A detailed description thereof is omitted.

[0115] A reflective polarizer can reflect some of the circularly polarized light incident from the phase difference layer and re-incident it into the phase difference layer or transmit the remaining part.

[0116] In one specific example, the reflective polarizer may be formed by alternately stacking two layers having different refractive indices. For example, the reflective polarizer may be a film stacked in the order of a high refractive index layer, a low refractive index layer, a high refractive index layer, and a low refractive index layer.

[0117] Among the pancake lens assemblies, the first lens, the phase difference layer, and the reflective polarizer can be purchased and used as commercially available products.

[0118] Figure 1 is a conceptual diagram of a stereoscopic image display device according to one embodiment.

[0119] Referring to FIG. 1, a stereoscopic image display device includes a display unit 100; a first polarizing plate 200 having a first phase difference layer 220, a first polarizer 210, and a second phase difference layer 230; and a pancake lens assembly 300 including a first lens 310, a phase difference layer 320, and a reflective polarizer 330. Light ultimately emitted through the pancake lens assembly 300 can be recognized by a user's eye 10.

[0120] Referring to FIG. 1, 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, passes through the phase difference layer 320 again, becomes circularly polarized, and is then reflected again by the first lens 310, passes through the phase difference layer 320, and is emitted in a linearly polarized state through the reflective polarizer 330.

[0121] In a pancake lens assembly, the reflective polarizer may further include a third polarizer on the outermost side of the stereoscopic display device, i.e., on the side opposite the phase contrast layer.

[0122] The third polarizer can provide the effect of minimizing ghost images by absorbing linearly polarized light in a different direction from the linearly polarized light emitted from the reflective polarizer (linearly polarized light substantially orthogonal to the linearly polarized light emitted from the reflective polarizer).

[0123] The third polarizer has a light absorption axis in the in-plane direction, and the light absorption side can be substantially orthogonal to the light absorption axis of the first polarizer of the first polarizing plate. Here, 'substantially orthogonal' can include an angle of 90° or a range of -5° to +5° from 90°.

[0124] In one embodiment, the optical absorption axis of the third polarizer may be substantially identical to the mechanical direction of the third polarizer.

[0125] The third polarizer can be manufactured in substantially the same manner as described for the first polarizer described above.

[0126] A protective layer having the protective layer or the functional coating layer formed thereon may be further adhered to one or both sides of the third polarizer.

[0127] Figure 5 is a conceptual diagram of a three-dimensional image display device according to one embodiment.

[0128] Referring to FIG. 5, instead of the pancake lens assembly 300 of FIG. 1, a pancake lens assembly 300' may be included, which includes a first lens 310, a phase difference layer 320, a reflective polarizer 330, and a third polarizer 340. The third polarizer 340 transmits some of the linearly polarized light emitted from the reflective polarizer 330 and absorbs linearly polarized light substantially perpendicular thereto, thereby minimizing ghost images.

[0129] Display section

[0130] The display portion may include a conventional display portion having a light-emitting element. The light-emitting element may include at least one of an organic light-emitting element, an inorganic light-emitting element, or an organic-inorganic light-emitting element.

[0131] Below, another example of a stereoscopic image display device is described.

[0132] The above stereoscopic image display device may further include a second polarizing plate between the first polarizing plate and the pancake lens assembly.

[0133] The second polarizing plate includes a second polarizer, a third phase difference layer, and a fourth phase difference layer, as described below. The second polarizing plate can increase light efficiency by transmitting circularly polarized light emitted from the first polarizing plate in a circularly polarized state or by emitting light other than circularly polarized light emitted from the first polarizing plate in a circularly polarized state.

[0134] 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 assembly side of the second polarizer.

[0135] In one specific example, the third phase difference layer and the fourth phase difference layer may each have reverse wavelength dispersion.

[0136] In one specific example, the short wavelength dispersion of each 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. Within the above range, the internal transmittance can be increased, thereby increasing the brightness of the optical display device.

[0137] In one specific example, the third phase difference layer can have an in-plane retardation of 115 to 125 nm, for example, 119 to 123 nm, at a wavelength of 450 nm. The third phase difference layer can have an in-plane retardation of 135 to 145 nm, for example, 139 to 143 nm, at a wavelength of 550 nm. The third phase difference layer can have an in-plane retardation of 140 to 150 nm, for example, 142 to 146 nm, at a wavelength of 650 nm. Within the above ranges, the above-described short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0138] In one specific example, the fourth phase difference layer can have an in-plane retardation of 115 to 125 nm, for example, 119 to 123 nm, at a wavelength of 450 nm. The fourth phase difference layer can have an in-plane retardation of 135 to 145 nm, for example, 139 to 143 nm, at a wavelength of 550 nm. The fourth phase difference layer can have an in-plane retardation of 140 to 150 nm, for example, 142 to 146 nm, at a wavelength of 650 nm. Within the above ranges, the above-described short-wavelength dispersion and long-wavelength dispersion can be easily achieved.

[0139] In one embodiment, the third phase difference layer may have substantially the same short-wavelength dispersion and long-wavelength dispersion as the fourth phase difference layer. This may eliminate the problem of providing a uniform image due to different wavelength-specific light output from the user's perception, as the degree of circular polarization varies by wavelength. Here, "substantially the same" includes not only a case where the error is 0, but also a value within the range of -0.001 to +0.001 from 0.

[0140] The third phase difference layer and the fourth phase difference layer each have a ground axis in the in-plane direction, and the ground axes of the two are substantially orthogonal.

[0141] According to one embodiment, the ground axis of the third phase difference layer may be substantially 45° with respect to the reference. The ground axis of the fourth phase difference layer may be substantially 135° with respect to the reference. Within the above range, the degree of circular polarization of light emitted from the display unit according to wavelength can be increased.

[0142] According to another embodiment, the ground axis of the third phase difference layer may be substantially 135° with respect to the reference. The ground axis of the fourth phase difference layer may be substantially 45° with respect to the reference. Within the above range, the degree of circular polarization of light emitted from the display unit according to wavelength can be increased.

[0143] In this specification, the term "reference" refers to the absorption axis of the first polarizer in the first polarizing plate. The absorption axis of the first polarizer is the mechanical direction of the first polarizer. When the display unit has a horizontal direction, which is the long side, and a vertical direction, which is the short side, the absorption axis of the first polarizer may be substantially in the same direction as the horizontal direction.

[0144] In one specific example, the third phase difference layer may have a thickness-wise phase difference of 50 to 80 nm at a wavelength of 550 nm, for example, 50, 55, 60, 65, 70, 75, 80 nm, for example, 55 to 75 nm. In this range, the in-plane phase difference described above can be easily achieved, and may help to thin the second polarizing plate.

[0145] In one specific example, the third phase difference layer may have a degree of biaxiality of 0.7 to 1.1, for example, 0.7, 0.8, 0.9, 1.0, 1.1, for example, 0.8 to 1.0, at a wavelength of 550 nm. In this range, the above-described in-plane phase difference can be easily achieved, and it can help to thin the second polarizing plate.

[0146] In one specific example, the fourth phase difference layer may have a thickness-wise phase difference of 50 to 80 nm, for example, 55 to 75 nm, at a wavelength of 550 nm. Within this range, the in-plane phase difference described above can be easily achieved, and may assist in thinning the second polarizing plate.

[0147] In one specific example, the fourth phase difference layer may have a degree of biaxiality of 0.7 to 1.1, for example, 0.8 to 1.0, at a wavelength of 550 nm. Within this range, the above-described in-plane phase difference can be easily achieved, and may assist in thinning the second polarizing plate.

[0148] The third phase difference layer and the fourth phase difference layer may each have a thickness of 1 to 40 μm, for example, 1.5 to 35 μm. Within the above range, they may be used in the first polarizing plate.

[0149] There are no restrictions on the materials of the third phase difference layer and the fourth phase difference layer, as long as they can satisfy the wavelength dispersion and phase difference characteristics described above. The third phase difference layer and the fourth phase difference layer may each be a liquid crystal layer or a non-liquid crystal layer.

[0150] The above liquid crystal layer and the non-liquid crystal layer are omitted as they have been described in detail in the first polarizing plate. Of course, the third phase difference layer and the fourth phase difference layer may also further include the optical film described above.

[0151] The third phase difference layer and the fourth phase difference layer may each further include an optical film. The optical film can facilitate the formation of the coating layer without affecting the phase difference of the third phase difference layer and the fourth phase difference layer. Since the optical film is substantially the same as described above, its description is omitted.

[0152] The second polarizer can linearly polarize the circular polarizing plate incident from the third phase difference layer and output it to the fourth phase difference layer.

[0153] The second polarizer has an optical absorption axis in the in-plane direction, and the optical absorption axis can be substantially parallel to the optical absorption axis of the first polarizer in the first polarizing plate. Here, 'substantially parallel' means 0° or an angle of -5° to +5° from 0°.

[0154] The second polarizer may have an orthogonal transmittance of 0.1% or less, for example, 0 to 0.1%, or 0.01 to 0.1%. In this range, it may be advantageous to provide an effect of minimizing ghost images by enhancing an anti-reflection effect in a device having an angle relationship between the above-described ground axes.

[0155] The second polarizer may have a polarization degree of 99% or more, for example, 99.99% to 100%, and a single-light transmittance (Ts) of 42% or more, for example, 42 to 45%. By simultaneously satisfying the polarization degree and single-light transmittance, the polarizer can significantly reduce reflectance when laminated on a phase difference laminate.

[0156] The light absorption axis of the second polarizer may be the stretching direction, for example, the machine direction (MD) of the polarizer, when manufacturing the polarizer from the polyvinyl alcohol-based film. The second polarizer may include a polyvinyl alcohol-based polarizer manufactured by uniaxially stretching the polyvinyl alcohol-based film. In one specific example, the first polarizer may be manufactured by dyeing, stretching, crosslinking, and color correction processes of the polyvinyl alcohol-based film. A polarizer having both the above-described polarization degree and light transmittance can be achieved by appropriately changing the conditions in the above-described dyeing, stretching, crosslinking, and color correction processes.

[0157] The second polarizer may have a thickness of 5 μm to 40 μm. Within this range, it may be used in a polarizing plate.

[0158] A resin layer may be further laminated on the assembly side of the second polarizer.

[0159] In one specific example, the resin layer may be formed directly on the assembly side of the second polarizer and bonded to the assembly side of the second polarizer. Here, “directly formed” means that no other adhesive layer, bonding layer, and / or curable coating layer is formed between the second polarizer and the resin layer. The resin layer may further enhance the ghost image removal effect by covering fine irregularities formed on the surface of the second polarizer. The resin layer may be a cured product of a composition including at least one of a thermosetting resin and an ultraviolet-curable resin. The thermosetting resin and the ultraviolet-curable resin may be selected from general types known to those skilled in the art. For example, the resin layer may be a cured product of a composition including a (meth)acrylic resin.

[0160] In another specific embodiment, a laminate of the resin layer and the optical film may be formed on the assembly side of the second polarizer. The optical film may increase the mechanical strength of the second polarizer, and the resin layer may further enhance the ghost image removal effect by covering the fine irregularities formed on the surface of the optical film. The resin layer and the optical film may be substantially the same as described above.

[0161] In one specific example, the resin layer may be, but is not limited to, a hard coating layer.

[0162] The second polarizing plate may further have a protective layer, a functional coating layer, or a protective layer formed on the outermost side of the assembly.

[0163] The above protective layer can protect the second polarizer, increase the reliability of the second polarizing plate, and increase the mechanical strength of the second polarizing plate. If the mechanical properties of the second polarizing plate can be secured even without the protective layer, the protective layer may be omitted.

[0164] The above protective layer can be formed on the assembly side of the fourth phase difference layer.

[0165] The protective layer may include at least one of an optically transparent protective film or a protective coating layer. The protective film may include a film formed of at least one of a cellulose ester resin including triacetyl cellulose (TAC) or the like, a cyclic polyolefin resin including amorphous cyclic polyolefin (COP) or the like, a polycarbonate resin, a polyester resin including polyethylene terephthalate (PET) or the like, a polyethersulfone resin, a polysulfone resin, a polyamide resin, a polyimide resin, an acyclic-polyolefin resin, a poly(meth)acrylate resin including polymethyl methacrylate resin, a polyvinyl alcohol resin, a polyvinyl chloride resin, and a polyvinylidene chloride resin, but is not limited thereto.

[0166] The protective coating layer can be formed from an active energy ray-curable resin composition containing an active energy ray-curable compound and a polymerization initiator. The active energy ray-curable compound can include at least one of a cationic polymerizable curable compound, a radical polymerizable curable compound, a urethane resin, and a silicone resin.

[0167] The protective layer may be a phase-free layer or may have an in-plane phase difference of a predetermined range. For example, the protective layer may have an in-plane phase difference of less than 5000 nm, or greater than 5000 nm, or 120 to 160 nm, or 5 to 0 nm at a wavelength of 550 nm. Within the above range, the polarizing plate can be protected without affecting the effect of the phase-differentiation layer stack.

[0168] The protective layer may have a thickness of 10 μm or less, or 5 μm to 300 μm, or 5 μm or less, or 5 μm to 200 μm. In the above range, it may be used in a polarizing plate.

[0169] The functional coating layer may be formed on one or both sides of the protective layer to provide additional functions to the protective layer or the first polarizing plate. The functional coating layer may include, but is not limited to, one or more of a hard coating layer, an anti-fingerprint layer, an anti-reflection layer, an anti-glare layer, a low-reflection layer, and an ultra-low-reflection layer.

[0170] In one specific example, the functional coating layer may be a low-reflection layer, an anti-reflection layer, or an anti-glare layer. The low-reflection layer, the anti-reflection layer, or the anti-glare layer may minimize ghost images by reflecting unnecessary light that may enter from the outside or absorbing light reflected at the interface. The first polarizing plate may include at least one of a low-reflection layer, an anti-reflection layer, and an anti-glare layer.

[0171] For example, the low-reflection layer and the anti-reflection layer may each have a minimum reflectivity of 3% or less, for example, 0 to 2%. Within the above range, ghost images can be minimized.

[0172] For example, the anti-glare layer may have an external haze of 0 to 50% and an internal haze of 0 to 10%. Within the above range, ghost images can be minimized.

[0173] The above low-reflection layer, anti-reflection layer, and anti-glare layer can be easily manufactured by methods known to those skilled in the art.

[0174] Fig. 7 is a cross-sectional view of a second polarizing plate of one embodiment.

[0175] Referring to FIG. 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 sequentially bonded to the assembly (not shown) side of the second polarizer 410, and a protective layer 440 having a functional coating layer formed thereon.

[0176] Although not shown in FIG. 7, when bonding the second polarizer, the third phase difference layer, the fourth phase difference layer, and the protective layer, an adhesive layer or a pressure-sensitive adhesive layer (e.g., a pressure-sensitive adhesive (PSA) layer) may be laminated.

[0177] Figures 8 and 9 illustrate the axial relationship between the first polarizing plate of one embodiment and the phase difference layer during assembly.

[0178] Referring to FIG. 8, the light absorption axis 211 of the first polarizer 210 forms substantially 45° with the slow axis 221 of the first phase difference layer 220, forms substantially 135° with 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 are substantially orthogonal, the absorption axis 411 of the second polarizer 410 forms substantially 45° with the slow axis 421 of the third phase difference layer 420, the absorption axis 411 of the second polarizer 410 forms substantially 135° with the slow axis 431 of the fourth phase difference layer 430, and the slow axis 421 of the third phase difference layer 420 and the slow axis 431 of the second phase difference layer 430 can be substantially orthogonal. there is.

[0179] Referring to FIG. 9, the light absorption axis 211 of the first polarizer 210 forms substantially 135° with the slow axis 221 of the first phase difference layer 220, forms substantially 45° with 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 are substantially orthogonal, the absorption axis 411 of the second polarizer 410 forms substantially 135° with the slow axis 421 of the third phase difference layer 420, the absorption axis 411 of the second polarizer 410 forms substantially 45° with the slow axis 431 of the fourth phase difference layer 430, and the slow axis 421 of the third phase difference layer 420 and the slow axis 431 of the second phase difference layer 430 can be substantially orthogonal. there is.

[0180] According to one embodiment, the second polarizing plate may have a light transmittance of 3% or less, for example, 0 to 3%, at a wavelength of 380 nm. Within this range, the light-emitting element of the display unit may be prevented from being damaged by UV rays incident from the outside. Methods for achieving the above light transmittance are known to those skilled in the art. For example, a method of including a light absorbing agent that absorbs light at the wavelength of 380 nm described above in one of the first polarizing plates may be considered.

[0181] Figure 6 is a conceptual diagram of a stereoscopic image display device of another embodiment.

[0182] Referring to FIG. 6, a second polarizing plate 400 having a second polarizer 410, a third phase difference layer 420, and a fourth phase difference layer 430 may be additionally placed between the pancake lens assembly 300 and the first polarizing plate 200 compared to FIG. 1.

[0183] Although not shown in FIG. 6, a second lens may be additionally laminated between the second polarizing plate 400 and the first polarizing plate 200.

[0184] The second lens can magnify the light perceived by the user by magnifying the circularly polarized light emitted from the first polarizing plate.

[0185] The second lens may be configured to have both surfaces curved to facilitate the above-described function. For example, the second lens may be a spherically concave surface, a spherically convex surface, a planar surface, a rotationally symmetric aspherical surface, or a free-form shape.

[0186] The second lens may be formed of glass or plastic, and the second lens may be manufactured according to methods known in the art for making pancake lenses.

[0187]

[0188] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0189]

[0190] Example 1

[0191] A polyvinyl alcohol film (Kuraray, Japan, thickness before stretching: 60 ㎛) was dyed in an iodine aqueous solution at 55°C, and stretched 6 times along the MD axis of the film to produce a first polarizer (light transmittance: 44%, orthogonal transmittance: 0.07%, thickness: 10 ㎛).

[0192] A triacetyl cellulose film was laminated to one side of a first polarizer, and a composition containing an acrylic resin was coated and cured on one side of the triacetyl cellulose film, thereby manufacturing a laminate formed in the order of the first polarizer, the triacetyl cellulose film, and the resin layer.

[0193] A first polarizing plate was manufactured by laminating phase difference layers on both sides of the manufactured laminate in the order of first phase difference layer (liquid crystal layer) - first polarizer - triacetyl cellulose film - resin layer - second phase difference layer (liquid crystal layer). The first phase difference layer and the second phase difference layer each have reverse wavelength dispersion, and the short wavelength dispersion and long wavelength dispersion are shown in Table 1 below. The first phase difference layer and the second phase difference layer were each manufactured using nematic liquid crystal.

[0194] A module for a three-dimensional image display device was manufactured by arranging the first polarizing plate manufactured above, the display unit including the OLED element, and the pancake lens assembly as shown in Fig. 1.

[0195] At this time, the ground axis of the second phase difference layer in the first polarizing plate forms a 90° angle with the ground axis of the phase difference layer in the pancake lens assembly.

[0196] The light absorption axis of the polarizer in the first polarizing plate forms a 45° angle with the ground axis of the first phase difference layer, and the ground axis of the first phase difference layer and the ground axis of the second phase difference layer form a 90° angle.

[0197]

[0198] Example 2

[0199] In Example 1, a module for a stereoscopic image display device was manufactured in the same manner as in Example 1, except that the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer were changed as shown in Table 1 below.

[0200]

[0201] Example 3

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

[0203] A triacetyl cellulose film was laminated to one side of a second polarizer, and a composition including an acrylic resin was coated and cured on one side of the triacetyl cellulose film, thereby manufacturing a laminate in which a second polarizer, a triacetyl cellulose film, and a resin layer were formed.

[0204] A second polarizing plate was manufactured by laminating phase difference layers on both sides of the manufactured laminate in the order of a third phase difference layer - a second polarizer - a triacetyl cellulose film - a resin layer - a fourth phase difference layer. The third phase difference layer and the fourth phase difference layer each have reverse wavelength dispersion, and the short wavelength dispersion and long wavelength dispersion are shown in Table 1 below. The third phase difference layer and the fourth phase difference layer were each manufactured using a nematic liquid crystal.

[0205] A module was manufactured in the same manner as in Example 1, except that the second polarizing plate manufactured above was additionally placed between the first polarizing plate and the pancake lens assembly.

[0206]

[0207] Examples 4 and 5

[0208] In Example 3, a module for a stereoscopic image display device was manufactured in the same manner as in Example 3, except that the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer were changed as shown in Table 1 below.

[0209]

[0210] Comparative Examples 1 and 2

[0211] In Example 1, a module for a stereoscopic image display device was manufactured in the same manner as in Example 1, except that the short-wavelength dispersion and long-wavelength dispersion of the phase difference layer were changed as shown in Table 1 below.

[0212]

[0213] Comparative Example 3

[0214] A module for a stereoscopic image display device was manufactured in the same manner as in Example 1, except that the ground axis of the second phase difference layer in the first polarizing plate was at an angle of 45° to the ground axis of the phase difference layer in the pancake lens assembly.

[0215]

[0216] The modules for the three-dimensional image display device of the examples and comparative examples were evaluated as follows, and the results are shown in Table 1.

[0217] *Resolution (MTF, modulation transfer function) (unit: %): This was evaluated using Radiant's ProMetric equipment, measuring the difference between bright and dark areas of the screen (contrast ratio). A higher MTF indicates higher resolution.

[0218] MTF calculation formula = (maximum contrast ratio - minimum contrast ratio) / (maximum contrast ratio + minimum contrast ratio) x 100

[0219] *Light leak: Diagonal light leaks were observed with the naked eye in a darkroom. If they were not visible to the naked eye, they were expressed as “none.” Depending on the intensity of the light leak, they were evaluated as weak, medium, and strong.

[0220] First polarizing plateSecond polarizing plateAngular resolutionLight leakFirst phase difference layerSecond phase difference layerThird phase difference layerFourth phase difference layerShort wavelength dispersionGrowth wavelength dispersionShort wavelength dispersionGrowth wavelength dispersionShort wavelength dispersionGrowth wavelength dispersionShort wavelength dispersionGrowth wavelength dispersionExample 10.8621.0240.8621.024----9085None Example 20.8641.0230.8641.023----9086None Example 30.8621.0240.8631.0200.8621.0240.8621.0249091None Example 40.8581.0220.8631.0210.8621.0240.863 1.0209092No comparison example 50.8551.0220.8631.0210.8641.0230.8611.0219091No comparison example 10.9101.0120.8631.020----9051Heavy comparison example 20.7911.0780.8631.020----9061Heavy comparison example 30.8551.0220.8631.021----4526Strong

[0221]

[0222] *Angle: The angle formed by the ground axis of the second phase contrast layer and the ground axis of the phase contrast layer in the pancake lens assembly.

[0223]

[0224] As shown in Table 1 above, the stereoscopic image display device of the embodiment can eliminate light leakage occurring at the edge within the viewing angle on the viewer's side and have high resolution.

[0225]

[0226] Simple modifications or changes of the present invention can be easily implemented by a person having ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims

1. At least a display unit having a light-emitting element, a first polarizing plate and a pancake lens assembly are provided. The first polarizing plate comprises 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 assembly side of the first polarizer. The above pancake lens assembly includes a phase contrast layer, The ground axis of the second phase difference layer is substantially orthogonal to the ground axis of the phase difference layer in the pancake lens assembly, A stereoscopic image display device, wherein the short wavelength dispersion of each 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. A stereoscopic image display device according to claim 1, wherein the first polarizing plate is positioned between the display unit having the light-emitting element and the pancake lens assembly.

3. A stereoscopic image display device in the first paragraph, wherein the ground axis of the first phase difference layer is substantially orthogonal to the ground axis of the second phase difference layer.

4. A stereoscopic image display device according to claim 1, wherein the first polarizer has an orthogonal transmittance of 0.1% or less.

5. A three-dimensional image display device in the first paragraph, wherein the first polarizer further has a resin layer laminated on the assembly side.

6. A three-dimensional image display device according to claim 5, wherein the resin layer is a hard coating layer.

7. A three-dimensional image display device in the first paragraph, wherein the display unit is formed in a horizontal direction as the long side and a vertical direction as the short side, and the absorption axis of the first polarizer is in the same direction as the horizontal direction.

8. A stereoscopic image display device according to claim 1, further comprising a second polarizing plate between the first polarizing plate and the pancake lens assembly.

9. A stereoscopic image display device according to claim 8, wherein the second polarizing plate comprises: 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 assembly side of the second polarizer.

10. A stereoscopic image display device in claim 9, wherein the short wavelength dispersion of each 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. A stereoscopic image display device in claim 9, wherein the ground axis of the third phase difference layer is substantially 45° with respect to the absorption axis of the first polarizer, and the ground axis of the fourth phase difference layer is substantially 135° with respect to the absorption axis of the first polarizer.

12. A 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. A stereoscopic image display device in claim 9, wherein the second polarizer has an orthogonal transmittance of 0.1% or less.

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

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

Images