TWI468733B - Pressure sensitive adhesive film for an orientating treatment in a photo-orientable layer - Google Patents

Description

Pressure sensitive mucosa for directional treatment in a photoalignable layer

The present invention relates to a method for preparing a pressure sensitive mucosa, a laminate film, an optical filter or a stereoscopic image display device for directional processing in a photoalignable layer.

The present application claims priority to Korean Patent Application No. 2010-0005907 to the Korean Intellectual Property Office on January 22, 2010, the content of which is hereby incorporated by reference.

The stereoscopic image display device is a display device that can display an image with a sense of depth. Conventional display devices only display information of a two-dimensional plane (ie, a visual display plane), so that there are severely limited problems in information loss, and in particular, information on the depth of the displayed object is lost.

The stereoscopic image display device can display an object in three dimensions, which not only displays a two-dimensional plane, but also displays a spatial state, so that the original three-dimensional information of the object can be displayed, thereby displaying more realistic information.

The technology for displaying three-dimensional images can be divided into glasses type and glasses-free type. In addition, the glasses type can be divided into a polarized glasses type and a liquid crystal shutter glass type (LC shutter glass), and the non-glasses type can be divided into a stereoscopic/multi-view point binocular disparity (volume type). (volumetric), holographic and similar styles.

The present invention is directed to a method of producing a pressure sensitive mucosa, a laminate film, an optical filter, or a stereoscopic image display device for directional processing in a photoalignable layer.

The present invention relates to a pressure sensitive mucosa for use in a directional treatment in a photoalignable layer, comprising a substrate formed with at least one light transmissive portion and at least one light blocking portion.

The pressure sensitive mucosa is detailed below.

In one embodiment, the pressure sensitive mucosa can be used during a process of orientation processing wherein the light orientable layer can be oriented by illuminating the light orientable layer. In a specific embodiment, the pressure sensitive film can be used for orientation processing to form a pattern including at least a first orientation area and at least a second orientation area in the light orientable layer, wherein the first orientation area has a first Orienting direction, and the second orientation zone has a second orientation direction that is different from the first orientation direction, or forms an area comprising at least two regions having different orientation directions. During the aligning process, the substrate on which at least one of the light transmitting portions and the at least one light blocking portion are formed may serve as a reticle. In particular, when the film is a pressure sensitive film, the film can be attached to the light orientable layer for orientation treatment, that is, the gap between the substrate and the photoalignable layer is scarcely present, so that non-directionality can be avoided. Area to form an orientation pattern with high accuracy.

As used herein, a "photo-orientable layer" can include all types of orientable layers commonly used in the art, including molecules that can be oriented in a predetermined direction by illumination. In one embodiment, the photoalignable layer can be an orientable layer that can be oriented by irradiation with polarized ultraviolet light (such as linearly polarized ultraviolet light), and the rear photoalignable layer can be induced by interaction with the liquid crystal compound. The orientation of the liquid crystal compound formed on the settable layer.

In one embodiment, the photoalignable layer can be an orientable layer for use in an optical filter for a stereoscopic image display device. An example of an optical filter for a stereoscopic image display device may include a patterned retarder for a stereoscopic image display device.

The term "light transmitting portion" as used herein refers to a substrate region through which light can be transmitted from the upper side or the lower side of the substrate, and the term "light shielding portion" as used herein refers to illumination from the upper side or the lower side of the substrate. A region of the substrate that cannot penetrate light.

Fig. 1 is a cross-sectional view showing an embodiment of a substrate (10) included in a pressure sensitive mucosa. As shown in FIG. 1 , the substrate (10) of the pressure sensitive mucous membrane comprises at least one light transmitting portion (T) and at least one light blocking portion (B), wherein light irradiated by the thickness direction can penetrate the light transmitting portion, and the light shielding portion It can block or absorb light. Light is indicated by the arrows in Figure 1. One or two or more light transmitting portions and one or two or more light blocking portions may be formed in the substrate.

The shape of the light transmitting portion and the light shielding portion is not particularly limited and may be formed according to an orientation pattern required for the light alignable layer.

In one embodiment, the light transmitting portion and the light shielding portion may have strip shapes extending in the same direction, and may be alternately arranged in the short side direction of the strip shape. Figure 2 shows a schematic view of a substrate as seen from the upper side of the substrate. In the substrate (10) of FIG. 2, the light transmitting portion (T) and the light shielding portion (B) have strip shapes extending in the same direction, and are alternately arranged in the short side direction of the strip shape.

In the example in which the light transmitting portion (T) and the light shielding portion (B) respectively have strip shapes extending in the same direction and are alternately arranged in the short side direction of the strip shape, the distance between the portions (ie, the width and phase of the light shielding portion) The interval between the adjacent light-shielding portions and the interval between the adjacent light-shielding portions are not particularly limited, and may be controlled depending on the use of the light-orientable layer. Figure 2 shows the spacing as P and the spacing as V.

For example, when the light orientable layer is a light orientable layer used for the optical filter in the stereoscopic image display device, the distance between the light transmitting portion and the light shielding portion may be a unit pixel forming a right eye image or forming a left eye image. The unit pixel is twice the width. Conventionally, as shown in FIG. 6, the stereoscopic image display device may include components for displaying images, such as a display panel (62), and an optical filter (63) such as a regular compensation film. Moreover, as described above, the component for displaying an image may include a unit pixel (left eye unit pixel (UL)) for forming a left eye image and a unit pixel for forming a right eye image (right The eye unit pixel (UR), both of which have strip shapes extending in the same direction, and are alternately arranged in the direction of the strip short sides, as shown in FIG. As described above, when the optical filter of the stereoscopic image display device uses a light-orientable layer coated with a pressure sensitive film, the value of the pitch (P) preferably has a unit pixel (UR) or (in the display image element). UL) twice the width of the equivalent value. In Figure 3, the width of the unit pixel (UR) or (UL) is indicated as W1 or W2.

As used herein, "equal value" includes substantially equivalent values that do not detract from the scope of the advantages of the invention, and which may include a variety of factors (such as process variations and variations).

For example, a cell with a width equal to twice the equivalent value includes an error within ±60 μm, an error within ±40 μm, or an error within ±20 μm.

In the present invention, as described above, the distance between the substrates can be controlled to avoid the occurrence of non-oriented regions after the alignment treatment, and to form an orientation pattern with high accuracy. Therefore, when the stereoscopic image display device uses the optical filter including the above-described orientable layer, it is possible to avoid the occurrence of so-called crosstalk in the device.

In addition, as described above, the interval between adjacent light-shielding portions (such as (V) in FIG. 2) preferably has a unit pixel (UR) or (UL) width in the display image element of the stereoscopic image display device (eg, Two times equal value of (W1) or (W2) in Fig. 3. As used above, the term "equal value" as used herein refers to approximately equal values, for example, it can include errors within ±30 μm, errors within ±20 μm, or errors close to ±10 μm. .

In the present invention, the interval can be controlled to be equal to the cell pixel width, and the non-directional region can be prevented from being formed after the alignment process to form an orientation pattern with high accuracy. Moreover, when an optical filter including the above-mentioned fixable layer is used in the stereoscopic image display device, the polarization transforming parts can each correspond to the cell pixels with high accuracy, so that so-called crosstalk can be avoided in the device. .

In the substrate of the present invention, the shape of the light transmitting portion and the light shielding portion is not limited to the above-described strip shape, and may be changed depending on the shape of the display image element or other application to which the light alignable layer is applicable.

For example, when the light alignable layer is a light alignable layer used in the optical filter in the stereoscopic image display device, and the unit pixels forming the left eye image and the right eye image in the display image element form a cross strip pattern, The light transmitting portion and the light blocking portion may also form a cross strip pattern corresponding to the unit pixel pattern. In this example, the distance between the light transmitting portion and the light blocking portion and the interval can be controlled in the same manner as described above. For example, the distance between the light transmitting portion and the light blocking portion may be substantially equal to twice the width of the unit pixel (forming the intersecting strip pattern), and the interval between the adjacent light blocking portions may be substantially equal to the cell pixel width. As described above, the distance and interval between the transparent strip portion and the light shielding portion intersecting strip pattern may be longitudinal or lateral spacing and longitudinal or lateral spacing, and the unit pixel width in the unit pixel cross strip pattern may be vertical or Horizontal width.

In the present invention, the substrate may include: a light-transmitting plate, and a light-shielding or light-absorbing ink that forms a light-shielding portion on the plate.

That is to say, the light-shielding or light-absorbing ink can be printed on the light-transmitting plate according to the desired pattern to form a light-shielding portion, thereby producing a substrate.

As mentioned above, a light-transmissive plate is a plate that allows an effective amount of light to pass through, wherein the light system is used to orient the light-orientable layer, such as ultraviolet light, and the effective amount is to direct the light. The amount of light that is effectively oriented by the layer. For example, the light-transmitting plate may be a plate having a low light absorption rate, and may be a plate having a light absorption rate of approximately 10% or less for light having a wavelength close to 320 nm or less. The light-transmitting plate may be exemplified by a cellulose plate (such as a cellulose triacetate plate) or an olefin plate (such as a plate formed of a norbornene derivative), but the light-transmitting plate usable here is not limited thereto, as long as It has a suitable light transmitting property. The thickness of the board is not particularly limited and can be controlled based on application, light transmittance, and the like.

The board as described above can also serve as a substrate for the protective film, which can be used to avoid alignment film contamination and improve the orientation during the preparation of the optical filter process. In a specific embodiment, the light shielding portion can be directly formed on the substrate of the protective film. Therefore, the film can be used not only as a protective film but also as a pressure sensitive film to serve as a light mask. Accordingly, the high-accuracy optical filter productivity can be increased by a simple method of illuminating the orientable film before and after the film is attached, without requiring additional equipment.

The kind of the ink which forms the light-shielding portion in the sheet is not particularly limited, and any light-shielding or light-absorbing ink known in the art can be used. As described above, an ink containing an inorganic dye such as carbon black, graphite or oxidized steel or an organic dye such as an azo dye or a titanium pigment dye can be exemplified as an example, and the above ink can be combined with a suitable binder and/or Or the solvent is mixed before printing.

As described above, the printing method for forming the light shielding portion is not particularly limited, and an example thereof may be used, such as screen printing or gravure printing, or selective printing of spray ink.

Here, the printing height of the ink can be close to 0.1 μm to 4 μm, preferably close to 0.5 μm to 2.0 μm. However, the printing height is not limited to this. For example, if the printing height is too low, the light-shielding property is lowered, or if the printing height is too high, it is difficult to use the film as a protective film, so the printing height can be controlled based on the above factors.

The pressure sensitive mucosa may further comprise a pressure sensitive adhesive layer formed on at least one side of the substrate, and the pressure sensitive adhesive layer may be used to attach the substrate to the light orientable layer. As described above, the attachment may mean a state in which there is almost no gap between the substrate and the photo-orientable layer. 4 is a cross-sectional view of an exemplary sexy pressure-sensitive adhesive film, as shown in FIG. 4, the pressure-sensitive adhesive film may include: a substrate (10) formed with at least one light transmitting portion (T) and at least one light shielding portion (B); A pressure sensitive adhesive layer (20) is formed on one side of the substrate (10).

As described above, the material and thickness of the pressure-sensitive adhesive layer are not particularly limited, and may be appropriately selected in consideration of the directional processing conditions and the like. For example, the pressure-sensitive adhesive layer may include a light-transmitting pressure-sensitive adhesive, and examples thereof include an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a polyisobutylene pressure-sensitive adhesive, and a rubber pressure-sensitive adhesive (such as styrene-butyl) Ethylene rubber, SBR), polyvinyl ether pressure-sensitive adhesive, epoxy pressure adhesive, melamine pressure-sensitive adhesive, polyester pressure-sensitive adhesive, phenolic pressure-sensitive adhesive or crepe pressure adhesive, or at least A mixed sensitizing adhesive of two of the above materials.

The invention also relates to a laminated film for preparing an optical filter, comprising: a substrate; a photoalignable layer formed on the substrate; and a pressure sensitive film attached to the photoalignable layer .

The kind of the substrate used in the laminated film is not particularly limited, and it can be exemplified as a substrate which is conventionally used for an optical filter. A conventional glass substrate or a plastic substrate can be used as the substrate. The plastic substrate may be exemplified by using cellulose triacetate (TAC), cyclic olefin copolymer (COP), polyacrylate (Pac), polyether oxime (PES), polycarbonate (PC), polyether ether ketone ( PEEK), polymethyl methacrylate (PMMA), polyether phthalimide (PEI), polyethylene naphthalene (PEN), polyethylene terephthalate (PET), polyimine (PI), polyfluorene A plastic substrate made of (PSF), polyvinyl alcohol (PVA), polyarylate (PAR), and/or amorphous fluororesin.

In a specific embodiment, when the optical filter is a regular compensation film, the (-)c plate characteristic can be used, R _{e is} close to 10 nm or less (preferably close to 5 nm or less), and R _{th is} close to 300 nm or less. (Substrate is preferably close to 100 nm, more preferably close to 60 nm, especially preferably below 15 nm), and the substrate having a refractive index close to 1.33 to 1.53 is used as a plastic substrate.

As stated above, the (-)c plate characteristic means that the relationship of "N _x =N _y >N _z " is satisfied, and R _e is a value calculated by "(N _x -N _y )×d", and R _th is a value calculated by "{(N _x + N _y )/2 - N _z } × d"). N _x means the refractive index of the substrate plane along the slow axis direction, N _y means the refractive index of the substrate plane along the fast axis direction, and N _z is the refractive index of the substrate along the thickness direction. d refers to the thickness of the substrate.

For example, when the optical filter is a regular compensation film, the use of the plastic substrate having the above optical anisotropy can maximize the compensation film performance in the device and minimize crosstalk, so that the device has excellent brightness. Moreover, optical filters of light weight, thinness, and excellent flexibility can be obtained by using such a plastic substrate.

Traditionally, if a plastic substrate is used as the substrate of the optical filter, due to the inherent characteristics of the plastic substrate, the formation temperature, solvent and/or the shrinkage of the directional layer during the preparation process may seriously affect the substrate, so An directional pattern with high accuracy is formed. However, by using the pressure sensitive film of the present invention for orientation treatment, the advantages of the plastic substrate can be extremely exhibited without deriving the above problems.

The kind of the orientable layer in the laminated film is not particularly limited, and any kind of orientable layer conventionally used in the art can be used. In one embodiment, the orientable layer can include a compound that is subjected to a cis-trans isomerization reaction, a Fries rearrangement reaction, and/or a dimerization reaction initiated by linearly polarized ultraviolet light. The orientation direction is determined, and the compound can induce the orientation of adjacent liquid crystal compounds depending on the orientation direction thereof. By way of example, the orientable layer may comprise a monomer, oligomer or polymeric compound having a choice selected from the group consisting of azobenzene, styryl benzene, cumarine, chalcone (chalcone). At least one functional group or group in the group of fluorine and cinnamate, and preferably may comprise a norbornene resin having a fluorine or cinnamate group.

The method of forming the orientable layer on the substrate is not particularly limited, and the above-mentioned compound which has been diluted with a suitable solvent can be exemplified by a conventional coating method such as roll coating, spin coating or bar coating. Coated on a substrate. Further, the coating thickness of the orientable layer is not particularly limited.

In one embodiment, the photo-orientable layer can be a photo-orientable layer that is subjected to primary orientation processing. For example, before attaching the pressure sensitive film, the light-alignable layer can be irradiated with linearly polarized ultraviolet light for the initial orientation treatment. In the initial orientation treatment, it is preferred to irradiate the entire surface of the orientable layer with linearly polarized ultraviolet light.

If more than one linearly polarized ultraviolet light is applied to orient the light orientable layer, the orientation direction is determined by the last linearly polarized ultraviolet light. Accordingly, if the orientable layer contained in the laminated film is initially oriented using linearly polarized ultraviolet light having a predetermined direction, and then the linearly polarized ultraviolet light is used after attaching the pressure sensitive film (the direction and the initial orientation) Processing the linearly polarized ultraviolet light direction is different) performing a second orientation treatment, thereby effectively forming an orientation pattern comprising at least one first orientation area and at least one second orientation area, wherein the first orientation area has a first orientation The direction, and the second orientation region has a second orientation direction that is different from the first orientation direction, or includes at least two regions having different orientation directions.

In a specific embodiment, the linear orientation ultraviolet light may be used for the initial orientation treatment, and the linearly polarized ultraviolet light may be a linear polarization ultraviolet light, which intersects with the light transmissive portion and the light shielding portion edge formed in the pressure sensitive mucosa. Preferably, the angle formed by the non-right angle is formed, and the linearly polarized ultraviolet light having an angle of substantially 45 degrees is formed to intersect the edge of the light transmitting portion and the light shielding portion formed in the pressure sensitive film. In the present invention, when defining an angle, it may include an error within ±10 degrees, an error within ±5 degrees, or an error within ±3 degrees. In the above example, the second directional treatment may be performed using linearly polarized ultraviolet light, and the linearly polarized ultraviolet light of the second directional treatment may be formed by intersecting with the edge of the light transmitting portion and the light shielding portion formed in the pressure sensitive mucosa. Linearly polarized ultraviolet light with a non-orthogonal angle. Further, in this example, the linearly polarized ultraviolet light of the second orientation treatment preferably has a direction which forms an angle of nearly 90 degrees with the direction of the linearly polarized ultraviolet light of the initial alignment treatment. By controlling the direction of the initial and second orientation processes, an optical filter that provides excellent performance of the device can be provided.

The pressure sensitive mucosa may be attached to a photo-orientable layer that has been subjected to primary orientation treatment or unoriented to produce a laminate film. In the case where the pressure sensitive mucous membrane comprises a pressure sensitive adhesive layer, the pressure sensitive adhesive layer can be attached to the light orientable layer through the pressure sensitive adhesive layer. The pressure sensitive mucosa is preferably closely adhered to the photoalignable layer. The term "closely attached" as used herein refers to a state in which there is almost no gap between the pressure sensitive film and the light orientable layer. By attaching the pressure sensitive mucous membrane to the light orientable layer, the diffusion of the illumination light between the gaps can be avoided, and the light having the desired uniform intensity can be irradiated onto the light orientable layer. It is also possible to avoid blurring of the boundaries between the orientation areas and to prevent the formation of non-directional areas.

The invention also relates to a method of making an optical filter using the laminated film of the invention. The optical filter preparation method may include a step of illuminating the light of the laminated film through the substrate of the laminated film in the laminated film.

When the light orientable layer is illuminated through the pressure sensitive mucus, the light can only pass through the light transmissive area of the pressure sensitive film, so only the light orientable layer corresponding to the light transmissive area of the pressure sensitive film is oriented. That is, the orientation direction caused by the initial orientation treatment of the region of the light-visient layer corresponding to the pressure-sensitive adhesive film may be changed, or the unoriented region of the light-sensitive layer of the light-sensitive layer may be changed. Orientation.

In one embodiment, as described above, the photo-orientable layer can be a photo-alignable layer that has been initially oriented by linearly polarized ultraviolet light. The linearly polarized ultraviolet light may have a linearly polarized ultraviolet light that intersects with an edge of the light transmitting portion and the light shielding portion (formed in the pressure sensitive film) to form a non-orthogonal angle, and more preferably has a light transmitting portion and a light shielding portion ( Formed in the pressure sensitive mucosa) the edges intersect to form a linearly polarized ultraviolet light having an angle of approximately 45 degrees. In this example, the light irradiated in the process may be the light used for the second directional treatment, and the light used for the second directional treatment may have the light transmissive portion and the light shielding portion (formed in the sensible pressure) The edge of the mucosa intersects to form a linearly polarized ultraviolet light in a non-orthogonal angle, which may also form an angle of approximately 90 degrees with the direction of the linearly polarized ultraviolet light of the initial orientation treatment.

Figure 5 is a diagram showing an exemplary preparation method of the optical filter of the present invention. As shown in Figures 5(a) to (d), the optical filter preparation method may include: forming a photo-orientable layer (2) on the substrate (1) (Fig. 5(a)); by linear polarization Ultraviolet light (arrow) for initial orientation of the photoalignable layer (2) (Fig. 5(b)); adhesion of the pressure sensitive mucosa (3) to the photoalignable layer (2) (Fig. 5(c)) And the second orientation of the photoalignable layer by a linearly polarized ultraviolet light (arrow) having a direction different from the direction of the linearly polarized ultraviolet light of the initial orientation treatment (Fig. 5(d)). By the above treatment, regions (21) and (22) having different orientation directions can be formed in the photoalignable layer.

The method for preparing an optical filter of the present invention may further comprise: removing the pressure sensitive film (3) after illuminating, and then forming a liquid crystal layer (4) on the light alignable layer (2), as shown in FIG. 5(e) and ( An exemplary illustration of f).

The method of forming the liquid crystal layer (4) is not particularly limited, and examples thereof may include: (a) coating a photocrosslinkable or photopolymerizable liquid crystal compound on the photoalignable layer for orientation, and then (b) The photo-crosslinking or photopolymerization of the liquid crystal compound. By the above treatment, regions (41) and (42) in which the alignment directions of the liquid crystal compounds are different can be formed on the photoalignable layer.

The type of the liquid crystal compound is not particularly limited, and it can be selected in consideration of the application of the optical filter. For example, when the optical filter is a regular compensation film, the liquid crystal compound may be a compound which can be oriented according to the orientation pattern of the photoalignable layer, and then converted into a liquid crystal polymer layer by photocrosslinking or photopolymerization, wherein liquid crystal polymerization The layer has a λ/4 phase delay characteristic. Using this type of liquid crystal compound, a regular compensation film can be obtained which can separate the irradiation light into left-handed circularly polarized light and right-handed circularly polarized light. In the field, various liquid crystal compounds which can be used depending on the optical filter application are known, and all of the above compounds can be used in the present invention.

As described above, the method of aligning the liquid crystal compound with the alignment pattern of the photo-alignable layer after coating the liquid crystal compound on the photo-alignable layer is not particularly limited, and various known alignment methods can be appropriately selected and used.

Thereafter, appropriate light may be irradiated to crosslink or polymerize the aligned liquid crystal compound to form a liquid crystal layer (e.g., a phase retardation layer).

The invention also relates to an optical filter comprising: a substrate; and a photoalignable layer formed on the substrate and having at least a first orientation region and at least a second orientation region, first The orientation area has a first orientation direction, and the second orientation area has a second orientation direction that is different from the first orientation direction, wherein the area ratio of the non-oriented area of the photo-orientable layer relative to the overall area of the photo-orientable layer It is 10% or less.

In one embodiment, the optical filter can be an optical filter used in a stereoscopic image display device, which is preferably a regular compensation film used in a stereoscopic image display device.

In the above optical filter, the substrate and the photo-alignable layer which can be used can be as described above.

In the optical filter, an orientation pattern is formed on the photo-orientable layer, and specifically, an orientation pattern including at least one first alignment region and at least one second alignment region may be formed on the photo-orientable layer, wherein The first orientation zone is processed to have a first orientation direction, and the second orientation zone is processed to have a second orientation direction that is different from the first orientation direction. In a specific embodiment, the first orientation area and the second orientation area may have strip shapes extending in the same direction, and may be alternately arranged in the light orientable layer in the direction of the strip short sides.

In the optical filter, the non-oriented area ratio of the light-orientable layer to the entire surface of the light-orientable layer is 10% or less, preferably 5% or less, more preferably 2% or less. For example, in the conventional orientation method, when light passes through the gap between the light-orientable layer and the reticle, a phenomenon such as light diffusion occurs, thereby forming a non-directional region.

However, in the present invention, the orientation treatment can be performed in a state in which the pressure-sensitive adhesive film (as a photomask) is closely attached to the light-orientable layer, so that the formation of the non-oriented region can be minimized.

As stated above, the area ratio of the non-directional areas can be evaluated as follows. That is, if the optical filter film is placed between the two polarizers (the light absorption axes are perpendicular to each other), the orientation direction of the optical filter is appropriately arranged along the light absorption axis of the polarizer, and then the polarizer is irradiated with the light source. Only non-directional areas will cause light leakage. Therefore, in the above state, the area where light leakage occurs can be observed by a polarizing microscope to evaluate the area ratio of the non-oriented area.

Further, the optical filter may have a crosstalk ratio of 5% or less, more preferably 2% or less. The crosstalk ratio can be calculated by the following formula 1.

[Formula 1]

X _T =(X _TL +X _TR )/2

In the formula 1, X _T represents the crosstalk ratio of the stereoscopic image display device to which the optical filter is applied, X _TL represents the crosstalk ratio observed by the left eye of the stereoscopic image display device to which the optical filter is applied, and X _TR represents the applied optics. The crosstalk ratio observed by the right eye of the stereoscopic image display device of the filter.

In Formula 1, X _TL and T _TR can be calculated from the following Formulas 2 and 3, respectively.

[Formula 2]

X _TL ={(L _(LB-RW) -L _(LB-RB) /(L _(LW-RB) -L _(LB-RB) )}×100

[Formula 3]

X _TR ={(L _(LW-RB) -L _(LB-RB) /(L _(LB-RW) -L _(LB-RB) )}×100

In the formulas 2 and 3, L _(LB-RW) represents the luminance estimated by the left-eye pixel in the stereoscopic image display device to which the optical filter is applied and the right-eye pixel is white, L _{(LB- RB)} represents the brightness estimated when the left-eye pixels and the right-eye pixels of the stereoscopic image display device using the optical filter are black, and L _(LW-RB) represents the stereoscopic image display device to which the optical filter is applied. The brightness of the middle left eye is white and the right eye is black.

The method for evaluating the brightness required for the above formulas 2 and 3 is not particularly limited and can be measured using a conventional method known in the art.

In the present invention, since the photo-alignable layer can be oriented using the above-described pressure sensitive film, it is possible to avoid formation of a non-directional region, thereby providing an optical filter having a low crosstalk ratio.

The optical filter of the present invention may further comprise a liquid crystal layer formed on the photoalignable layer. Further, when the optical filter is a regular compensation film, the liquid crystal layer may be a phase retardation layer. In one embodiment, the phase retardation layer can be a phase retardation layer having a λ/4 retardation. In the phase retardation layer, a pattern including at least a first region and at least a second region may be formed according to an orientation pattern of the light orientable layer below, wherein the first region has a first slow axis of the first direction, and The two regions have a second slow axis in a second direction (different from the first slow axis direction). Moreover, by way of example, the first and second regions may have strip shapes extending in the same direction and may be alternately arranged in the direction of the strip short sides, as shown in FIG.

The first slow axis direction of the first region may intersect with the first and second region edges to form a non-orthogonal angle, for example, may form an angle of about 45 degrees with the first and second region edges. Moreover, the second slow axis direction of the second region may intersect the first and second region edges to form a non-orthogonal angle and form an angle of approximately 90 degrees with the first slow axis direction.

When a phase retardation layer having a λ/4 retardation and a slow axis relationship is applied to a stereoscopic image display device, the phase retardation layer can form left-handed circularly polarized light and right-handed circularly polarized light, respectively.

The present invention also relates to a stereoscopic image display device including the above optical filter.

In one embodiment, the optical filter may be a regular compensation film, and the stereoscopic image display device may be a polarized glasses stereoscopic image display device.

In the above-described stereoscopic image display device, the components or operating elements constituting the device are not particularly limited, and all of the conventional device types are applicable as long as the device includes the optical filter of the present invention.

Figure 6 is a cross-sectional view of an exemplary apparatus of a particular embodiment.

The display device (60) may be a polarized glasses type, which can display a three-dimensional image to a viewer (not shown) by placing polarized glasses. The display device (60) may be composed of a backlight unit (61), a display panel (62) (such as a liquid crystal display panel), and a compensation film (63) arranged in sequence. As described above, the compensation film (63) may be the optical filter of the present invention, which may include: a substrate (631); a photo-alignable layer (not shown in FIG. 6) formed on the base And a liquid crystal layer (632) formed on the photo-orientable layer and having the first region (632A) and the second region (632B). The liquid crystal layer (632) can be a phase retardation layer. In the display device (60), the surface of the compensation film (63) is an image display surface and is oriented toward the viewing side. Moreover, in a particular embodiment, the display device (60) is arranged such that the image display surface is parallel to the vertical surface (vertical surface, y-z plane in Figure 6). Furthermore, the image display device may be rectangular in shape, and the longitudinal direction of the image display surface is parallel to the horizontal direction (y-axis direction in the drawing). In addition, when the polarized glasses are placed on the front side of the viewer's eyeball, the viewer can see the image display surface.

The backlight unit (61) may have a reflector, a light source, and an optical sheet (not shown). The reflector deflects the light from the source to the side of the optical sheet and has reflection, scattering, diffusion, and the like. Examples of the reflecting plate include a polyethylene terephthalate (PET) foam. Therefore, the light emitted from the light source can be effectively utilized. The light source illuminates the display panel (62) from the back side, and may include, for example, a plurality of line sources arranged in parallel at regular intervals, or a plurality of point sources arranged in a two-dimensional array. Further, the line light source may be, for example, a hot cathode fluorescent lamp (HCFL), a cold cathode fluorescent lamp (CCFL), or the like. The point light source can be exemplified by a light emitting diode (LED) or the like. The optical sheet can uniformly disperse the brightness of the light from the light source or adjust the deviation of the light from the light source to the desired range, such as a diffusing plate, a reflective polarizing element, and a phase difference plate. Furthermore, the light source can be of the edge light type. In this case, a light guide plate or a light guide film may be used as needed.

The display panel (62) may be a transmissive liquid crystal display panel, wherein a plurality of pixels are two-dimensionally arranged in the direction of the rows and columns, and each pixel is driven according to the image signal to display the image. As described above, the pixel examples may include, as shown in FIG. 3, left eye pixels and right eye pixels. As shown in FIG. 6, the display panel (62) may have a transparent substrate (622), a pixel electrode (623), an alignment film (624), and a liquid crystal layer (625), as exemplified by the backlight unit (10) side. An alignment film (626), a common electrode (627), a color filter (628), and a transparent substrate (629) (opposing substrate). Further, in the present invention, the first polarizing plate (621A) is attached to the transparent substrate (622), and the second polarizing plate (621B) is attached to the transparent substrate (629).

The first polarizing plate (621A) is disposed on the light incident side of the display panel (62), and the second polarizing plate (621B) is disposed on the light emitting side of the display panel (62). The polarizing plates (621A) and (621B) are optical shutters that transmit only light (polarized light) in a specific vibration direction. For example, the polarizing plates (621A) and (621B) are arranged such that their polarization axes are different from each other and at a specific angle (for example, 90 degrees), whereby the liquid crystal layer transmits or blocks the light emitted by the backlight unit (61). .

The absorption axis (not shown) of the first polarizing plate (621A) is set in a range in which the light emitted from the backlight unit (61) can be transmitted. For example, when the polarization axis of the light emitted by the backlight unit (61) is in the vertical direction, the transmission axis of the first polarizing plate (621A) is also in the vertical direction, when the polarization axis of the light emitted by the backlight unit (61) is in the horizontal direction. In the upper direction, the transmission axis of the first polarizing plate (621A) is also in the horizontal direction. Further, the light emitted by the backlight unit (61) is not limited to linearly polarized light, and may be circular or elliptical polarized light, or unpolarized light.

The absorption axis direction of the second polarizing plate (621B) is set within the transmittable range of the light transmitted by the display panel (62). For example, when the absorption axis of the first polarizing plate (621A) is in the horizontal direction, the absorption axis of the second polarizing plate (621B) is in a direction perpendicular to the horizontal direction (vertical direction). When the absorption axis of the first polarizing plate (621A) is in the vertical direction, the absorption axis of the second polarizing plate (621B) is in the direction perpendicular to the vertical direction (horizontal direction).

The transparent substrates (622) and (629) are transparent to visible light. Further, the transparent substrate on the side of the backlight unit (61) may have an active driving circuit formed thereon as an example. The circuit includes a thin film transistor (TFT, which is a driving element electrically connected to a transparent pixel electrode) and a line. An example of the pixel electrode (623) may include indium tin oxide (ITO), which serves as an electrode for each pixel. The alignment film (624) may, for example, comprise a polymeric material, such as a polyimine, which causes the liquid crystal to undergo an alignment treatment. The liquid crystal layer (625) may include, for example, a VA (vertical alignment) mode liquid crystal, a TN (twisted nematic) mode liquid crystal, or an STN (super twisted nematic) mode liquid crystal. Each pixel liquid crystal layer (625) can transmit or block light emitted by the backlight unit (61) in response to an applied voltage from a driving circuit (not shown). The common electrode (627) may include, for example, ITO as a common counter electrode. Arranging a filter portion (628A) for separating light emitted by the backlight unit (61) into three primary color splits such as red (R), green (G), and blue (B) to form a color filter ( 628). The color filter (628) has a black matrix portion (628B) that blocks the light in the region between the filter portions (628A) (corresponding to the pixel boundary).

In one embodiment, the optical filter (63) of the present invention can split the light irradiated from the second polarizing plate (621B) into left-handed circularly polarized light and right-handed circularly polarized light, and transmits the light to the polarized glasses. Viewers.

【advantage】

The present invention provides a pressure sensitive mucosa for directional treatment in a photoalignable layer and a method for preparing an optical filter using a pressure sensitive mucosa which minimizes the formation of non-oriented regions and forms an orientation pattern with high accuracy. Further, the present invention can provide an optical filter and a stereoscopic image display device having excellent performance.

The invention can be explained in more detail by the following examples and comparative examples of the invention, and the scope of the invention is not limited to the embodiments.

Example 1 Preparation of pressure sensitive mucosa for directional treatment

The light-shielding ink was printed on a cellulose triacetate (TAC) plate (UZ80, manufactured by FUJI), and a light-shielding region was formed on a cellulose triacetate plate (which is a light-transmitting plate). Here, the light shielding area is formed in a strip shape, and the light transmitting area and the light shielding area are alternately arranged as shown in FIG. 2 . The distance between the light-transmitting area and the light-shielding area (P) is about 1080 μm, and the distance between adjacent light-shielding areas is about 540 μm, and the ink printing height is about 1.5 μm. Thereafter, an acrylic pressure sensitive adhesive was used to form a pressure-sensitive adhesive layer on one side (relative to the printing side) of the TAC substrate to obtain a pressure-sensitive adhesive film for orientation treatment. Figure 7 is a photograph of the front side of the pressure sensitive mucosa.

Preparation of optical filters

An optical filter was prepared by using a pressure sensitive film as shown in FIG. First, a polycinnamate type photoalignable layer (2) is formed on a triacetate substrate (1) having a thickness of 80 μm, and a thickness of the photoalignable layer (2) after drying is 1,000. . The photo-alignable layer (2) is formed by coating a solution forming a photo-alignable layer on a substrate (1) by a roll coating method, and drying at 80 ° C for about 2 minutes to remove Solvent. The solution (polynorbornene: acrylic monomer: photoinitiator (weight ratio) = 2:1: 0.25) was obtained by polynorbornene (weight average molecular weight of 150,000, which has the following formula 1) The mixture of the cinnamate group and the acrylic acid monomer is mixed with a photoinitiator (Igacure 907) and dissolved in a cyclohexanone solvent, wherein the solid content of the polynorbornene is 2 wt%. (% by weight).

[Formula 1]

Subsequently, the photoalignable layer (2) was subjected to initial orientation by irradiation with linearly polarized ultraviolet light (300 mW/cm ² ). Controlling the polarization direction of the linearized ultraviolet light in the initial orientation, so that the polarization direction is approximately 45 degrees from the edge of the light-sensitive region (T) and the light-shielding region (B) of the pressure sensitive film (3) to be attached after the initial orientation treatment. Angle. After the initial orientation, the pressure sensitive adhesive film (3) is closely attached to the light-orientable layer (2) by pressure-sensitive adhesive layer. Next, the light-orientable layer (2) was irradiated with linearly polarized ultraviolet light (300 mW/cm ² ) for the second orientation treatment. In the second orientation, the polarization direction of the linearly polarized ultraviolet light is controlled such that it is at an angle of approximately 90 degrees to the polarization direction of the linearly polarized ultraviolet light of the initial orientation treatment. After the alignment process is completed, the pressure sensitive film (2) is peeled off and a phase retardation layer (4) having a λ/4 phase retardation characteristic is formed thereon. Specifically, the liquid crystal compound (LC242 ^TM, manufactured from BASF) was applied to the light may be oriented layer (2), and the thickness of the liquid crystal compound is dried 1 μm. The liquid crystal compound is oriented according to the orientation pattern of the photo-orientable layer (2), and is cross-linked and polymerized by irradiation of ultraviolet light (300 mW/cm ² ) for about 10 seconds to obtain a region containing two regions. An optical filter, wherein the two regions have slow axes of different directions depending on the orientation pattern of the photo-orientable layer (2).

Comparative example 1

The steps for preparing the optical filter are the same as those described in Embodiment 1, except that the photosensitive mask (2) is not used and the conventional photomask is used for orientation of the photoalignable layer. Specifically, the second directional treatment is to illuminate the light alignable layer after the initial directional treatment by using a ray mask, wherein the reticle is disposed on the light alignable layer, and the reticle is covered by the polarized ultraviolet light. The distance from the photo-orientable layer is maintained at 0.7 mm.

Comparative example 2

The steps for preparing the optical filter are the same as those described in Example 1 except that instead of using the pressure sensitive film (2) and the conventional mask for the orientation of the photoalignable layer. Specifically, the second directional treatment is to illuminate the light alignable layer after the initial directional treatment by using a ray mask, wherein the reticle is disposed on the light alignable layer, and the reticle is covered by the polarized ultraviolet light. The distance from the photo-orientable layer is maintained at 1.1 mm.

1. Evaluation of directional patterns

The orientation patterns of Example 1 and Comparative Examples 1 and 2 were evaluated. 8 is an enlarged view of the light-orientable layer after orientation of Embodiment 1, and FIG. 9 is an enlarged view of the phase retardation layer on the light-orientable layer after the orientation of Embodiment 1. Figure 10 is an enlarged view of the light-orientable layer after orientation of Comparative Example 1, and Figure 11 is an enlarged view of the phase retardation layer on the light-orientable layer after the orientation of Comparative Example 1. Figure 12 is an enlarged view of the light-orientable layer after orientation of Comparative Example 2. It is clearly shown in the figure that the edge of the orientation pattern can be clearly observed in Embodiment 1, and a phase retardation layer having high accuracy is formed. However, the edges of the orientation patterns in Comparative Examples 1 and 2 were not conspicuous.

2. Evaluation of non-directional area and crosstalk ratio

For the light orientable layers of Example 1 and Comparative Examples 1 and 2, the area of the non-oriented regions in the photo-orientable layer relative to the overall area of the photo-orientable layer was evaluated. In addition, the crosstalk ratio is evaluated for each of the aligned light orientable layers.

The optical filter is placed between two polarizers whose light absorption axes are perpendicular to each other, so that the orientation direction of the optical filter is along the light absorption axis of the polarizer, and then the polarizer is irradiated with the light source and observed by a polarizing microscope. The area where light leakage occurs, and then the area ratio of the non-directional area is evaluated.

In addition, the optical filter is applied to a conventional polarized glasses type stereoscopic image display device, and then the brightness of the right eye unit pixel and the left eye unit pixel is changed, thereby evaluating the center of the image display surface of the stereoscopic image display device by 1.8 m. The brightness of the place. The crosstalk ratio was calculated from the evaluated brightness using the general formulas 1 to 3.

The evaluation results are shown in Table 1 below.

Table 1 clearly shows that the non-directional area ratio and crosstalk ratio of the photo-orientable layer of Example 1 can be minimized.

Fig. 13 is a photograph of a stereoscopic image display device viewed using polarized glasses, wherein the device uses the optical filter manufactured in Example 1. Fig. 13(a) is a photograph of the right eye viewed by the polarized glasses, and Fig. 13(b) is a photograph of the left eye viewed by the polarized glasses.

As shown in FIG. 13, when the left-eye and right-eye images of the optical filter of the present invention having different polarization properties are viewed from one side of the polarized glasses, when the polarization direction and the phase retardation direction of the polarized glasses are perpendicular to each other, , the image will be displayed in black; and when the polarization direction and the phase of the retardation film of the polarized glasses are parallel to each other, the image will be displayed in white. In addition, when viewed from the other side of the polarized glasses, the black and white images of the same film are clearly exchanged.

1,631. . . Substrate

2. . . Light alignable layer

21,22,41,42. . . region

3. . . Pressure sensitive mucosa

4,625,632. . . Liquid crystal layer

10. . . Substrate

20. . . Pressure sensitive layer

60. . . Display device

61. . . Backlight unit

62. . . Display panel

621A. . . First polarizer

621 B. . . Second polarizer

622,629. . . Transparent substrate

623. . . Pixel electrode

624,626. . . Orientation film

627. . . Common electrode

628. . . Color filter

628A. . . Filter section

628B. . . Black matrix department

63. . . Optical filter

632A. . . First area

632B. . . Second area

B. . . Shading

T. . . Translucent part

P. . . spacing

V. . . interval

UR, UL. . . Unit pixel

W1, W2. . . width

1 is a cross-sectional view of an exemplary aspect of a substrate included in a pressure sensitive mucosa.

2 is an exemplary view of a substrate as seen from the upper side of the substrate.

3 is a view showing an exemplary aspect of a unit pixel (UL) forming a left eye image and a unit pixel (UR) shape forming a right eye image in an image element.

Figure 4 is a cross-sectional view showing an exemplary aspect of a pressure sensitive mucosa.

Fig. 5 is a view showing an exemplary aspect of a method of producing an optical filter of the present invention.

Fig. 6 is a cross-sectional view showing an exemplary aspect of the display device.

Figure 7 is a photograph of the front side of the preparation of the pressure sensitive mucosa.

Figure 8 is an enlarged photograph of the photo-alignable layer after orientation of Example 1.

Figure 9 is an enlarged photograph of the phase retardation film on the photoalignable layer after orientation in Example 1.

Figure 10 is an enlarged photograph of the photo-alignable layer after orientation of Comparative Example 1.

Figure 11 is an enlarged photograph of the phase retardation film on the photo-orientable layer after orientation of Comparative Example 1.

Figure 12 is an enlarged photograph of the photo-alignable layer after orientation of Comparative Example 2.

Fig. 13 is a photograph of a stereoscopic image display device viewed using polarized glasses, wherein the device uses the optical filter manufactured in Example 1.

10. . . Substrate

20. . . Pressure sensitive layer

B. . . Shading

T. . . Translucent part

Claims (8)

A pressure sensitive mucosa for directional treatment in a photoalignable layer, wherein the photoalignable layer is used for an optical filter in a stereoscopic image display device, and the pressure sensitive mucosa for directional treatment in the photoalignable layer comprises a substrate having at least one light transmissive portion through which light illuminating from an upper side or a lower side of the substrate can penetrate the substrate; and at least one light shielding portion passing through the light shielding portion Light illuminating the upper side or the lower side of the substrate cannot penetrate the substrate; and a pressure sensitive mucous layer formed on at least one side of the substrate and for attaching the substrate to the light alignable layer, wherein Each of the light transmitting portion and the light shielding portion has a strip shape extending in the same direction, and is alternately arranged in a short side direction of the strip shape, and wherein a distance between the light transmitting portion and the adjacent light shielding portion is The unit pixel of the right-eye image or the unit pixel width of the left-eye image formed in the display image element of the stereoscopic image display device is twice as large. The pressure sensitive mucosa for directional treatment in the photoalignable layer according to claim 1, wherein the interval between the light shielding portions has a unit pixel forming a right eye image or a unit pixel forming a left eye image. Two times the width is equal. a pressure sensitive film for directional treatment in a photoalignable layer according to claim 1, wherein the substrate comprises: a light transmissive plate; and a light blocking ink or a light absorbing ink to form the light transmissive plate The light shielding portion. A laminated film for preparing an optical filter, comprising: a substrate; A photo-alignable layer formed on the substrate; and the pressure-sensitive adhesive film according to claim 1, which is attached to the photo-alignable layer. The laminated film for preparing an optical filter according to claim 4, wherein the photo-orientable layer is a light-orientable layer which is subjected to initial orientation treatment. A method for preparing an optical filter, comprising: illuminating a light-orientable layer of the laminated film according to claim 4, wherein the substrate is in the pressure-sensitive adhesive film of the laminated film . The optical filter preparation method of claim 6, further comprising: after the illuminating, removing the pressure sensitive film, and forming a liquid crystal layer on the light orientable layer. The optical filter preparation method of claim 7, wherein the step of forming the liquid crystal layer comprises: (a) coating a photocrosslinkable or photopolymerizable liquid crystal compound on the photoalignable layer, Orientation is carried out, and then (b) the liquid crystal compound is subjected to photocrosslinking or photopolymerization.