KR20120080801A - Method of manufacturing the patterned retarder - Google Patents

Abstract

The present invention relates to a method of manufacturing a patterned retarder, and more particularly, to position a polarization filter having a light blocking portion and a wire grid pattern portion repeatedly formed on an alignment layer and irradiating light from an upper portion of the polarization filter to orient the light. By including an alignment step, the present invention relates to a method for producing a patterned retarder having less light loss due to scattering and interfacial reflection by using one polarizing filter, and allowing a continuous process to be easy for mass production and productivity improvement.

Description

Method of manufacturing the patterned retarder

The present invention relates to a method of manufacturing a patterned retarder that can be applied to a stereoscopic image display device or a transflective LCD using a polarizing glasses method.

Recently, various image display apparatuses such as liquid crystal display (LCD), electroluminescence (EL) display, plasma display (PDP), field emission display (FED), etc. have been reported realistically and three-dimensionally beyond time and space. The paradigm toward a superspatial three-dimensional (3D) image display device that is felt and enjoyed is changing.

In general, three-dimensional images representing a three-dimensional image is made by the principle of stereo vision through two eyes of a person. A method of realizing a three-dimensional effect by using a binocular parallax that appears because the two eyes are about 65 mm apart. to be.

The principle of binocular disparity is a method of capturing the left eye image viewed through the left eye and the right eye image viewed through the right eye from different angles with at least two stereoscopic image capturing cameras, and then separating them and delivering them to the viewer's eyes. . The two human eyes receive things through the retina at different angles, and these two images can be synthesized in the brain.

Three-dimensional stereoscopic imaging techniques can be broadly classified into a binocular parallax (stereoscopic technique) and a compound parallax (autostereoscopic technique). The binocular parallax method uses a parallax image of the left and right eyes having the largest stereoscopic effect, and includes a polarized glasses method and a glasses-free method.

The three-dimensional stereoscopic image device of the polarizing glasses method described in Japanese Patent Application Laid-Open No. 10-232365 and Korean Patent Publication No. 2008-0108034 is as follows.

The liquid crystal panel having a right eye image area R and a left eye image area L, a polarizing plate disposed on the front of the liquid crystal panel, and a rotation direction of the polarization axes of the right eye image and the left eye image which are disposed on the polarizing plate and pass through the polarizing plate are opposite to each other. And a three-dimensional stereoscopic image device having a patterned retarder that emits with circularly polarized light. In addition, it is provided with a polarized glasses for viewing the right eye image and the left eye image emitted from the stereoscopic image device as a stereoscopic image.

Patterned retarders applied to the three-dimensional stereoscopic imaging apparatus and a manufacturing method thereof are known in various ways. As disclosed in US Pat. No. 5,327,285, a photoresist is coated on a polarizing film in which a TAC (triacetyl cellulose) film and an iodine-stretched stretched PVA (polyvinyl alcohol) film are laminated, and after exposure to a predetermined portion, potassium hydroxide It is prepared by the method of treatment with solution to lose the phase difference delay function of a certain part.

On the other hand, Korean Patent Application No. 2000-0087186 discloses that the phase retardant material is coated on a transparent substrate and partially exposed the phase retardant material to light through a mask, whereby the chiral property is modulated and the original property is maintained. A method of manufacturing a stereoscopic image display device for forming an optical filter (optical film) in which parts are alternately arranged is provided.

However, the manufacturing method of US Pat. No. 5,327,285 suffers from a complicated manufacturing step following chemical etching, thus high manufacturing cost and low productivity. In the polarization filter manufacturing method of Korean Patent Application No. 2000-0087186, it is difficult to control the chiral characteristics of the retardant material with light intensity, so that the yield is low and there are many problems in practical use such as instability due to temperature.

In order to improve this, Korean Patent Publication No. 2010-0089782 discloses a pattern mask 50 in which light transmission regions and light blocking regions are alternately arranged up and down and left and right alternately so that different polarized light is selectively passed on the polymer membrane. And a polarizing plate 60 having two distinct areas, each of which transmits different polarizations, on the pattern mask 50, and irradiates ultraviolet rays from the upper part of the polarizing plate to the polymer film to each other in a micro area of the polymer film. A photo alignment method of forming alignment films having different alignment directions has been proposed (FIG. 5).

However, Korean Patent Publication No. 2010-0089782 discloses a low amount of light reaching the alignment layer per unit time due to light scattering and light loss due to interfacial reflection at the optical interface between the polarizing plate and the pattern mask. As a result, there was a disadvantage of low fairness and productivity.

The present invention can minimize light loss due to light scattering and interface reflection on the optical interface, and can form alignment layers having different alignment directions by a single light irradiation process, and do not include a separate mask. Therefore, the exposure equipment is simplified to provide a method of manufacturing a patterned retarder with improved mass production and productivity.

In order to solve the above problems, the method of manufacturing a patterned retarder according to the present invention places a polarization filter having a light blocking portion and a wire grid pattern portion repeatedly formed on an alignment layer, and irradiates light from an upper portion of the polarization filter. To a light orientation step.

The alignment layer may be aligned in a predetermined direction, and may include a photo alignment step of aligning the alignment layer in a direction different from that of the alignment layer.

The wire grid pattern portion may have a straight line shape.

In addition, the method of manufacturing a patterned retarder of the present invention includes a first polarization filter part, a second light blocking part and a first wire grid pattern part, in which a first light blocking part and a first wire grid pattern part are repeatedly formed on an alignment layer. And a light alignment step of positioning a polarization filter including a second polarization filter part repeatedly formed with a second wire grid pattern part in a different direction from the pattern, and irradiating and orienting light from an upper portion of the polarization filter.

The polarizing filter may be formed such that the first light blocking part of the first polarizing filter part and the second wire grid pattern part of the second polarizing filter part are adjacent to each other.

The alignment layer may be unoriented.

The shape of the first wire grid pattern portion and the second wire grid pattern portion may be a straight line, respectively.

The method may include forming a liquid crystal coating layer on the photo-aligned alignment layer.

The optical alignment step may include a film contact part moving while the film is in close contact; And a pattern forming unit which transmits the light irradiated from the light emitting unit to the film portion in close contact with the film adhesion unit and forms a polarization pattern on the film portion.

The pattern forming unit may include a polarization filter.

The distance between the curved surface of the polarizing filter provided on the pattern forming unit and the curved surface of the roller may be kept constant within the range of 50 to 150 μm.

According to the present invention, the light loss due to scattering, interfacial reflection, or the like is reduced by using one polarizing filter, and the amount of light reaching the alignment layer is high.

In addition, the present invention can form alignment films having different alignment directions in a photo alignment process by one light irradiation.

Since the pattern mask required in the one light irradiation step is not provided, the exposure equipment can be simplified.

In addition, the present invention can be produced in a patterned retarder in a continuous process to enable mass production and improve productivity.

1 and 2 show the polarization filter of the present invention,
3 and 4 show an example of a polarizing filter located on an alignment film according to the present invention,
5 illustrates a mask and a polarizer positioned on an alignment layer according to a comparative example (Korean Patent Publication No. 2010-0089782),
6 illustrates a configuration of an apparatus for manufacturing a patterned retarder according to an example of the present invention.
7 illustrates a configuration of an exposure system according to an example of the present invention.

The present invention can minimize light loss due to scattering of light and reflection of an interface at an optical interface using one polarizing filter, and enables formation of alignment films having different alignment directions in a photo alignment process by one light irradiation. It relates to a method for manufacturing a fire retarder.

Hereinafter, the present invention will be described in detail.

The method of manufacturing a patterned retarder according to the present invention includes a light alignment step of placing a polarization filter repeatedly formed with a light blocking portion and a wire grid pattern portion on an alignment layer, and irradiating light from an upper portion of the polarization filter to orient it. .

In the present invention, the polarizing filter may form polarized light that vibrates in a limited direction after passing the light vibrating in various directions through the polarizing filter, and only a part of the polarizing filters may form polarized light vibrating in the same direction. Refers to an optical element.

The alignment film is used that is oriented in a predetermined direction. The alignment film is dried and formed by applying a conventional alignment film forming composition onto a film.

The method for forming the alignment film oriented in the predetermined direction is not particularly limited, but non-contact type, such as polarized light exposure, is preferred as compared to the contact type such as a rubbing roll on the coating surface.

In the optical alignment step using the alignment layer oriented in a predetermined direction, as shown in FIG. 3, the light blocking unit 21 and the wire grid pattern unit 22 of FIG. 1 are repeatedly formed on the film 5 on which the alignment layer is formed ( 20) is positioned and orientated in a direction different from that of the alignment layer.

The method of using the polarizing filter according to the present invention can improve the resolution reduction of the exposure light as compared to the conventional method in which the polarizing plate 60 and the pattern mask 50 are separated. Specifically, since the polarizing plate 60 and the pattern mask 50 are separated and the light is diffracted as the exposure light proceeds by the interval therebetween, the resolution of the exposure light is reduced, but in the present invention, since the exposure light passes through one polarization filter, its resolution is reduced. The problem of degradation is not taken into account.

In addition, the method of manufacturing a patterned retarder according to the present invention includes a first polarization filter part, a second light blocking part and a first wire grid pattern, in which a first light blocking part and a first wire grid pattern part are repeatedly formed on an alignment layer. And a light alignment step of positioning a polarization filter including a second polarization filter part repeatedly formed with a second wire grid pattern part in a direction different from the negative pattern and irradiating light from an upper portion of the polarization filter.

At this time, the alignment film uses an unoriented alignment film.

In the optical alignment step using the non-oriented alignment layer, as shown in FIG. 4, the first light blocking unit 23 and the first wire grid pattern unit 24 of FIG. 2 are repeatedly formed on the film 5 on which the alignment layer is formed. A polarization filter 20 including a first polarization filter part 40, a second polarization filter part 41 in which the second light blocking part 25 and the second wire grid pattern part 26 are repeatedly formed is used. .

In this case, the second wire grid pattern portion 26 is patterned in a direction different from the pattern of the first wire grid pattern portion 24 to align the alignment layer to have alignment regions in different directions.

In the polarization filter, the first polarization filter part 40 and the second polarization filter part 41 are positioned side by side with respect to the advancing direction of the alignment layer, and the first light blocking part 23 of the first polarization filter part 40. The second wire grid pattern part 26 of the second polarization filter part 41 is formed to be adjacent to each other.

When using the polarizing filter of FIG. 2 for the oriented film oriented in a fixed direction, it is preferable to use the oriented film formed by the oriented film formation composition comprised from the component which is not fixed by the light exposure.

The light blocking part and the first and second light blocking parts respectively absorb and reflect incident light to prevent the light blocking part from reaching the alignment layer, and the wire grid pattern part and the first and second wire grid pattern parts are respectively incident. It is a structure which polarizes light to reach on an oriented film.

The shape of the wire grid pattern portion and the first and second wire grid pattern portions are each a straight line, specifically, a plurality of metal wires protruding in a parallel straight line shape are arranged at predetermined intervals. The metal wire is formed from aluminum (Al), silver (Ag), chromium (Cr), copper (Cu), nickel (Ni), Ti (titanium), gold (Au) or two or more alloys thereof.

The method of forming the wire grid pattern portion and the first and second wire grid pattern portions may use a conventional method in the art. For example, after the master pattern is formed, it is manufactured using a mold that is the reverse phase of the formed master pattern, and the metal layer and the polymer layer are sequentially stacked on the transparent protective film or glass substrate, and then the pattern is applied to the polymer layer using the mold. Mold. Next, a metal grid may be deposited on the molded pattern through gradient deposition to form a wire grid pattern. Alternatively, the wire grid pattern may be formed by etching the polymer layer of the molded pattern and forming a metal pattern by dry etching or wet etching the metal layer exposed on the surface, and then removing the polymer remaining on the formed metal pattern. .

In the wire grid pattern portion and the first and second wire grid pattern portions, the width (width of the pattern), the height (the height of the pattern), and the spacing between the metal wires (period of the pattern) of each metal wire are the same as the transmittance and the reflectance. The value may be adjusted according to the optical design related to the polarization characteristic. For example, the width of the pattern is 150 nm or less, preferably 10 to 100 nm, the height of the pattern is 600 nm or less, preferably 50 to 500 nm, and the period of the pattern is 300 nm or less, preferably 20 to 200 nm.

The length of the polarizing filter, the length of the first polarizing filter part and the second polarizing filter part may be adjusted according to the size and the moving direction of the alignment layer. Further, the size and spacing between the light shielding portion and the wire grid pattern portion, the first light shielding portion and the first wire grid pattern portion, and the second light shielding portion and the second wire grid pattern portion, and the spacing therebetween are the desired patterning. Can be adjusted according to the retarder.

Light is not particularly limited, but electron beams, ion beams, plasma beams, radiations, and the like may be used, and ultraviolet rays which are easy to handle are preferably used.

In the patterned retarder manufactured according to the present invention, it is preferable to perform the photonavigation step so that the orientation directions are perpendicular to each other. In this case, the vertical includes a case in which two lines form a 90 ° state as well as a substantially vertical effect.

After performing the photo alignment step, the alignment layer is cured to form a liquid crystal coating layer. The liquid crystal coating layer is formed by applying and drying a liquid crystal coating layer-forming composition containing a liquid crystal compound having optical anisotropy on the cured alignment film and having crosslinkability by light. The liquid crystal compound is preferably a substance having refractive index anisotropy of 0.05 or more, for example, using a reactive liquid crystal compound (RM).

Photocuring the dried coating layer to prepare a patterned retarder in which the liquid crystal is aligned in accordance with the alignment direction of the alignment layer.

According to the present invention, in addition to the optical alignment step performed using a specific polarization filter on the alignment layer, other parts, for example, the type of the alignment layer and the liquid crystal coating layer, the formation method, the characteristics such as thickness, the photo alignment conditions, etc. are applicable in addition to the above description. It may be appropriately selected and applied to exhibit optical characteristics generally required in the art.

On the other hand, the patterned retarder according to the present invention can be manufactured using a device generally used in the art.

As an example, as shown in Figure 6, the transfer unit for unwinding and / or winding and transporting the roll film; An alignment film forming unit (not shown) for forming an alignment film on the film to be transferred; A photo alignment unit for aligning the alignment film formed on the film by irradiating with light; After the liquid crystal coating layer is formed on the alignment layer, a manufacturing apparatus including a patterned retarder forming unit configured to irradiate light to form a patterned retarder may be used.

The first roll 7 and the second roll 9 of the conveying unit 11 are independently connected to a driving source (not shown) such as a motor and a power transmission member (not shown) such as a belt or a chain and rotated by receiving a driving force. It is desirable to be arranged so that it can. In addition, a plurality of guide rolls (not shown) and accumulators (not shown) for controlling the feeding amount of the film according to the process may be provided for maintaining the tension and transferring the stable film. In addition, the film 5 on which the alignment film is formed is preferably moved in a conventional roll to roll manner.

The alignment layer may be formed in the process immediately before the alignment by the alignment layer forming unit, and in some cases, the alignment layer may be formed on the film through a separate alignment layer forming process. In addition, a conventional drying apparatus can be used for an oriented film formation part, as needed, in order to harden the formed oriented film.

The patterned retarder forming portion 3 includes a mixed solution applying portion 31, a mixed solution drying portion 33, and a hardening portion 35.

In addition, after the patterned retarder forming unit 3, the present invention may include a defect inspection unit (not shown) to perform defect inspection of the patterned retarder. The defect inspection unit specifies a specified defect by scanning an optical filter, etc., and displays the specified defect using a marking device such as ink marking or barcode marking on the specified defect, or the defect information (shape, size, position) in a separate storage unit. ) May be stored and applied to a stereoscopic image display device.

The exposure system used in the optical alignment unit may be performed while closely contacting the film to a cylindrical roller as shown in FIG. 7 in order to minimize meandering and shaking of the film that proceeds continuously.

Specifically, the exposure system includes a film contact portion moving while the film is in close contact; And a pattern forming part configured to transfer the light irradiated from the light emitting part to the film part in close contact with the film contact part, to form a polarization pattern on the film part.

The film contact part is a cylindrical roller 160, it is preferable that the film (5) on which the alignment layer is formed moves while being in close contact with the curved surface of the roller.

The pattern forming unit 150 serves to transmit the light irradiated from the light emitting unit toward the rotation axis of the roller. The pattern forming unit includes the polarizing filter according to the present invention, and the distance between the curved surface of the polarizing filter provided in the pattern forming unit 150 and the curved surface of the roller 160 is maintained to be constant (AA '= BB' = CC '). .

The distance between the curved surface of the polarizing filter provided in the pattern forming unit 150 and the curved surface of the roller 160 is preferably maintained to 50 to 150㎛, preferably 50 to 100㎛.

In addition, the pattern forming unit 150 may be positioned without being particularly limited as long as it is a portion capable of forming a pattern, such as an inlet, a center, and an outlet of the roller.

In addition, the pattern forming unit preferably includes a chamber in which the internal air pressure is adjusted to adjust the curved surface of the polarizing filter.

The surface of the roller is preferably anti-reflective or scattering-free treatment.

In addition, the exposure system of the present invention includes a first reflector 120 for reflecting the light 110 output from the light emitting unit; A condenser 130 for condensing and transferring the light reflected by the first reflector; And a second reflector 140 reflecting the light transmitted from the light collector to the pattern forming unit.

In this case, the pattern forming unit may directly receive the light irradiated from the light emitting unit and transmit the light to the film part in close contact with the film contact part.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example 1

The triacetyl cellulose film was transferred by the transfer unit as in the manufacturing apparatus of FIG. 6. An acrylate alignment liquid was applied onto the film to be transferred, followed by hot air drying at 40 ° C. for 120 seconds to form an alignment film having a thickness of 1,000 μm. Subsequently, ultraviolet rays polarized with a 14mW exposure lamp were irradiated on the alignment layer to form an alignment layer oriented in a predetermined direction.

While moving the film on which the alignment layer is formed, the ultraviolet ray having a polarization filter of FIG. 1 is continuously irradiated with a UV of 20 mW / cm 2 while moving the substrate at a speed of 4 m / min for 1 second. It was formed to have an alignment direction different from that of the alignment layer by passing through only.

After the curing of the alignment layer was carried out, the liquid crystal coating layer-forming composition was applied, preliminarily dried at 80 ° C. for 20 seconds, and then dried at 110 ° C. for 5 seconds to form a coating layer having a thickness of 1.5 μm. Photocuring was performed to prepare a patterned retarder. The production speed of the patterned retarder was 4 m / min.

Example 2

In the same manner as in Example 1, a patterned retarder was prepared using an unoriented alignment film and the polarization filter of FIG. 2. The production speed of the patterned retarder was 8 m / min.

Example 3

A patterned retarder was manufactured in the same manner as in Example 1, using an exposure system in which a film was optically oriented while being in close contact with a cylindrical roller as shown in FIG. 7. At this time, the distance between the curved surface of the polarizing filter provided in the pattern forming unit 150 and the curved surface of the roller 160 was maintained at 70㎛. The production speed of the patterned retarder was 8 m / min.

Comparative example

A light polarizer having the same pattern as that of Example 1, but having a pattern mask 50 having a light transmitting region and a light blocking region repeatedly formed on the alignment layer as shown in FIG. 60) was positioned to make a patterned retarder. The production speed of the patterned retarder was 4 m / min.

Test Example

Optical loss according to the method of manufacturing the patterned retarder of the Examples and Comparative Examples was measured by the method and the results are shown in Table 1 below.

Light loss

The patterned retarder prepared above was placed on a polarizing plate whose absorption axes were perpendicular to each other, and the image passing through the polarizing plate and the patterned retarder was captured by a microscope (Olympus). The captured image was measured for luminance in a predetermined area using a digital image analysis program.

At this time, the captured image is a portion where light leakage is generated as shown in the following figure (right-comparative example, right-side example 1) in a plane shape or linear shape (gap between patterns). In the following captured image, the black portion is in a well-formed state, and the blurry portion is a double-orientation due to diffraction, resulting in an unclear orientation. At this time, in the comparative example, a pattern was formed in an up and down direction, and in Example 1, a pattern was formed in a direction from the upper right portion toward the lower left portion.

In the embodiment, the boundary between the patterns is narrow and clear, but in the comparative example, the boundary between the patterns is wide and the precision of the patterned retarder may be confirmed.

If the luminance is 0, the image is considered to be completely black and the light loss is 0%, and if the luminance is 100, it is considered to be completely white and the light loss is 100%.

division Example 1 Example 2 Example 3 Comparative example Light loss (%) 3 5 3 15 Production speed (m / min) 4 8 8 4

As shown in Table 1, Examples 1 to 3 according to the present invention was confirmed that the light loss is significantly lower while showing the production rate or more equivalent to the comparative example.

DESCRIPTION OF SYMBOLS 1: Light alignment part 3: Patterned retarder formation part
5: film in which alignment film was formed 7: first roll
9: 2nd roll 11: transfer part
13: light source 20: polarization filter
21: light shield 22: wire grid pattern portion
23: first light shielding portion 24: first wire grid pattern portion
25: second light shielding part 26: second wire grid pattern part
31 mixed solution coating unit 33 mixed solution drying unit
35: hardened part
40: first polarization filter unit 41: second polarization filter unit
50: pattern mask 60: polarizing plate
110: light source 120: first reflecting unit
130: light collector 140: second reflecting unit
150: pattern forming unit 160: roller

Claims (12)

On top of the alignment layer
Position the polarization filter formed by the light blocking portion and the wire grid pattern portion repeatedly,
And a light alignment step of irradiating and orienting light from the upper portion of the polarizing filter.
The method of claim 1, wherein the alignment layer is oriented in a constant direction.
The method of manufacturing a patterned retarder according to claim 2, comprising a light alignment step of aligning in a direction different from that of the alignment film.
The method of manufacturing a patterned retarder according to claim 1, wherein the shape of the wire grid pattern portion is a straight line.
On top of the alignment layer
A first polarization filter part in which the first light blocking part and the first wire grid pattern part are repeatedly formed, and a second polarization filter in which a second wire grid pattern part in a direction different from the pattern of the second light blocking part and the first wire grid pattern part is repeatedly formed Place the included polarization filter,
And a light alignment step of irradiating and orienting light from the upper portion of the polarizing filter.
The method of claim 5, wherein the polarizing filter is formed such that the first light blocking part of the first polarizing filter part and the second wire grid pattern part of the second polarizing filter part are adjacent to each other.
The method of claim 5, wherein the alignment layer is unoriented.
The method of manufacturing a patterned retarder according to claim 5, wherein the shapes of the first wire grid pattern portion and the second wire grid pattern portion are straight lines, respectively.
6. The method of claim 1 or 5, comprising forming a liquid crystal coating layer on the photo-aligned alignment film.
The method according to claim 1 or 5, wherein the optical alignment step is a film contact portion moving while the film is in close contact; And a pattern forming unit which transmits the light irradiated from the light emitting unit to the film portion in close contact with the film adhesion unit and forms a polarization pattern on the film portion.
The method of claim 10, wherein the pattern forming unit comprises a polarizing filter.
The method of claim 11, wherein the distance between the curved surface of the polarizing filter provided on the pattern forming unit and the curved surface of the roller is kept constant within a range of 50 to 150 μm.

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