KR101527165B1 - Method of fabricating patterned retarder using polarized pulse ＵＶ - Google Patents

Abstract

The present invention relates to a patterned retarder having a first and a second phase pattern by forming a first domain optically oriented in a first direction and a second domain optically oriented in a second direction by irradiating a polarizing pulse UV onto the alignment layer According to one embodiment of the present invention, there is provided a manufacturing method comprising the steps of: (a) preparing a substrate; (b) forming a photoreactive layer by applying a photoreactive agent on the substrate; And (c) exposing the photoreactive layer to form a photo alignment layer in which stripe-type first domains and second domains are alternately continuous, wherein the first domain is a first domain by a polarization pulse UV, And the second domain is optically oriented in a second direction by a polarizing pulse UV. The present invention also provides a method of manufacturing a patterned retarder using a polarization pulse UV.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a patterned retarder using a polarizing pulse UV,

The present invention relates to a method of manufacturing a patterned retarder, and more particularly, to a method of manufacturing a patterned retarder by forming a first domain optically oriented in a first direction and a second domain optically oriented in a second direction by irradiating a polarizing pulse UV onto the orientation film , And a method of manufacturing a pattern reliader having first and second phase patterns.

2. Description of the Related Art With advances in liquid crystal panel manufacturing technology, liquid crystal display devices have been widely used in the field of optical information processing.

TN (Twisted Nematic) display method is most widely applied as a liquid crystal display device applied to small and medium-sized displays in the related art. In this case, electrodes are arranged on two substrates, liquid crystal directors are twisted at 90 degrees, And applying a voltage to drive the liquid crystal director.

The TN mode liquid crystal display device provides excellent contrast and color reproducibility. Among them, the TN mode liquid crystal display device has a vertical alignment (VA) mode in which long axes of liquid crystal molecules are vertically aligned with the upper and lower display plates Liquid crystal display elements are in the spotlight because of their large contrast ratio. However, the TN type liquid crystal display device has a problem that the viewing angle is narrow.

In order to solve the viewing angle problem of the TN mode, there are a PVA mode (Patterned Vertically Aligned Mode) in which a cutout is applied to a liquid crystal display device of a vertical alignment mode, and a method of forming two electrodes on one substrate, An IPS mode (In-Plane Switching Mode) was introduced to control the director of the liquid crystal by the transverse electric field.

Thereafter, in order to improve the low aperture ratio and transmittance of the IPS mode, a counter electrode and a pixel electrode are formed as transparent conductors while a gap between the counter electrode and the pixel electrode is narrowed, A FFS mode (Fringe Field Switching Mode) for operating liquid crystal molecules by a fringe field has been developed.

In order to solve the problem that the light efficiency of the FFS mode does not reach the TN mode, the FIS mode has been developed. In addition, not only can the low transmittance between the pixel electrodes be improved in the conventional FFS mode, So that a liquid crystal display device capable of low voltage driving can be obtained.

Each of these modes has a unique liquid crystal arrangement and optical anisotropy. Therefore, in order to compensate the retardation due to the optical anisotropy of these liquid crystal modes, optical anisotropic optical retardation films corresponding to the respective modes are required. The optical phase difference film has been developed as a color compensation film of an LCD, but in recent years, various functions such as high wavelength dispersion, wide viewing angle, temperature compensation, and high retardation film have been required.

In recent years, there has been developed a display device capable of expressing a realistic image due to stereoscopic effect, that is, a display device capable of 3D image display in response to the increase in demand of a display device capable of realizing a 3D image.

In general, stereoscopic images expressing 3D are made by the principle of stereoscopic vision through two eyes. Using the binocular disparity that appears because the time difference of the two eyes, that is, the two eyes are separated by about 65 mm A 3D image display device capable of displaying stereoscopic images has been proposed.

A typical 3D image realization display device mainly includes a liquid crystal display device for displaying an image, a patterned retarder attached to the outer surface of the liquid crystal display device, and an image from the liquid crystal display device through the pattern drifter And optically transmissive glasses.

At this time, the patterned retarder is set to have a different phase value for the left eye image and the right eye image out of the 2D images coming from the liquid crystal display device, for example, to be left-handed circularly polarized light for the left eye image and rightward circularly polarized light for the right eye image And this requires the formation of optically oriented multi-domains at different angles. Regarding such a pattern reliader and its manufacturing method, a number of applications such as Korean Patent Laid-Open No. 10-2013-0035631 (Patent Document 1) and the like are disclosed.

A contact rubbing method of applying a polymer film such as polyimide to a substrate such as glass and rubbing the surface with fibers such as nylon or polyester in a predetermined direction is used as a conventional method of orienting the liquid crystal. The liquid crystal alignment by the contact type rubbing method as described above is advantageous in that a simple and stable alignment performance of liquid crystal can be obtained. However, when the fibers and the polymer film are rubbed, fine dust or electrostatic discharge (ESD) As the rolls become larger due to an increase in the process time and the enlargement of the glass, the process difficulties such as unevenness of rubbing strength can cause serious problems in manufacturing the liquid crystal panel.

In order to solve the problems of the contact type rubbing method as described above, studies on the production of a new non-contact type alignment film have been actively conducted. The non-contact alignment layer may be formed by photo-alignment, energy beam alignment, vapor deposition alignment, or lithography.

In particular, the photo-alignment method is a method in which a photoreactive material (optical isomerization, photo-dimerization, photodecomposition) caused by linearly polarized UV is bonded to a photoreactive polymer to form a uniform arrangement and thereby a liquid-crystal alignment film .

For this purpose, when irradiating linearly polarized ultraviolet light, the photoreactive material should be arranged in a certain direction and angle according to the polarization direction, and the liquid crystal alignment with the reactive liquid crystal should be well matched with the reactive liquid crystal . In particular, the photo alignment material forming the photo alignment layer should have good physical properties such as printability, orientation stability, and thermal stability.

Photochemical reaction (light dimerization) of cinnamate, coumarin, chalcone, stilbene, diazo, etc., optical isomerization reaction of cis-trans isomerization and molecular chain cleavage of decomposition It is known. There are cases in which the molecular light reaction by ultraviolet rays is applied to the liquid crystal alignment by ultraviolet ray irradiation through designing suitable alignment film molecules and optimizing ultraviolet ray irradiation conditions.

For example, Korean Patent Registration No. 10-0423213 (Patent Document 2) discloses a method for producing a liquid crystal alignment film characterized by imparting liquid crystal aligning ability by linearly polarized ultraviolet irradiation without rubbing treatment And a liquid crystal display element having the liquid crystal alignment film. These patents related to the photo-alignment method have been filed in many cases in Japan, Korea, Europe, and the United States, which are related to the LCD industry. However, after the initial idea has been derived, some of it is still in production, but it is not widely applied in industry as a whole.

This is because it is possible to induce a simple liquid crystal alignment by the photoreaction but it does not maintain or provide stable orientation characteristics in terms of external heat, light, physical impact and chemical impact. That is, the photo alignment method has lower productivity or reliability than the rubbing method. The main causes of these problems are lower anchoring energy and lower liquid crystal alignment stability than the rubbing method.

KR 10-2013-0035631 A (2013.04.09 open) KR 10-0423213 B1 (March 4, 2004 Enrollment)

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above-mentioned problems, and it is an object of the present invention to provide a patterning method using a polarizing pulse UV, which has an effect of improving productivity by maximizing the efficiency of photo- And to provide a retarder manufacturing method.

According to a preferred embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: (a) preparing a substrate; (b) forming a photoreactive layer by applying a photoreactive agent on the substrate; And (c) exposing the photoreactive layer to form a photo alignment layer in which stripe-type first domains and second domains are alternately continuous, wherein the first domain is a first domain by a polarization pulse UV, And the second domain is optically oriented in a second direction by a polarizing pulse UV. The present invention also provides a method of manufacturing a patterned retarder using a polarization pulse UV.

The step (c) may further include the steps of: (c-1) irradiating the photoreactive layer with a polarizing pulse UV polarized in a first direction to perform a front exposure; And (c-2) irradiating the photoreactive layer with a polarized pulse UV polarized in a second direction, blocking a region corresponding to the first domain using a photomask, and removing only a region corresponding to the second domain And partially exposing the substrate.

(D) applying, drying and curing the reactive liquid crystal on the secondarily exposed photo alignment layer.

At this time, the polarizing pulse UV preferably has an energy of 0.1 mJ / pulse to 500 J / pulse.

It is preferable that the polarizing pulse UV is irradiated at 1 Hz to 60 Hz.

It is preferable that the flash voltage of the polarizing pulse UV is 1 kV to 4 kV.

It is preferable that the exposure time by the polarizing pulse UV is 0.1 sec to 10.0 sec.

It is preferable that the exposure time and the exposure energy in the step (c-2) are larger than the exposure time and the exposure energy in the step (c-1).

In addition, the exposure distance by the polarizing pulse UV is preferably 0.5 cm to 10.0 cm.

According to the method of manufacturing the patterned retarder using the polarized pulse UV according to the preferred embodiment of the present invention, it is possible to shorten the formation time of the multi-domain by the exposure process and reduce the energy by using the polarized pulse UV, It is easy to produce.

1 is a flow diagram of a method of manufacturing a patterned retarder using a polarizing pulse UV according to an embodiment of the present invention;
FIGS. 2A to 2C are process charts of a method of manufacturing a patterned retarder using a polarizing pulse UV according to an embodiment of the present invention.
3 is a graph comparing peak power of general UV and pulse UV.
FIG. 4 is a photograph of a polarized light microscope according to the exposure time of general UV and pulse UV. FIG.
FIG. 5 is a graph comparing the micro-orientation distribution diagrams of the photo-alignment layers according to the exposure time of the general UV and the pulse UV.
6 is a graph comparing changes in retardation of a photo alignment layer with exposure time of general UV and pulse UV.
7 is a polarized light microscope photograph according to the exposure distance of the polarizing pulse UV.
8 is a graph showing a micro-orientation distribution diagram of the photo-alignment layer according to the exposure distance of the polarizing pulse UV.
9 is a graph showing a change in phase difference of the photo alignment layer depending on the exposure distance of the polarizing pulse UV.
FIG. 10 is a photograph of a polarized light microscope by frequency and frequency of a pulse UV at an exposure distance of 1.5 cm. FIG.
FIG. 11 is a graph showing the micro-orientation distribution of the photo-alignment layer by frequency and pulse voltage of the UV at an exposure distance of 1.5 cm. FIG.
12 is a graph comparing the phase difference of the photo-alignment layer with respect to the frequency of the pulse UV and the frequency of the pulse UV at an exposure distance of 1.5 cm.
Fig. 13 is a photograph of a polarized light microscope by frequency and frequency of pulsed UV at an exposure distance of 7.0 cm. Fig.
14 is a graph showing a micro-orientation distribution diagram of a photo-alignment layer by frequency and a pulse UV at an exposure distance of 7.0 cm.
FIG. 15 is a graph comparing changes in phase difference of the photo-alignment layer by the flash voltage and the frequency at the exposure distance of 7.0 cm.
16 is a graph comparing pre-tilt angles according to exposure time of general UV and pulse UV.
FIG. 17 is a polarized light micrograph of a comparison of the orientations according to the 0 ° / 45 ° multi-domain formation method in polarized pulse UV exposure. FIG.
18 is a graph comparing orientations according to the 0 ° / 45 ° multi-domain formation method in polarized pulse UV exposure.
FIG. 19 is a polarized light microscope photograph comparing the orientation properties according to the 0 ° / 90 ° multi-domain formation method in polarized pulse UV exposure. FIG.
FIG. 20 is a graph comparing orientations according to a 0 ° / 90 ° multi-domain formation method in polarized pulse UV exposure. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a method for manufacturing a patterned retarder using a polarizing pulse UV according to the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

In addition, the following embodiments are not intended to limit the scope of the present invention, but merely as exemplifications of the constituent elements set forth in the claims of the present invention, and are included in technical ideas throughout the specification of the present invention, Embodiments that include components replaceable as equivalents in the elements may be included within the scope of the present invention.

Example

FIG. 1 is a flowchart illustrating a method of manufacturing a patterned retarder using a polarizing pulse UV according to an embodiment of the present invention. FIGS. 2A to 2C illustrate a patterned retarder using a polarizing pulse UV according to an embodiment of the present invention. Fig. Hereinafter, a method for manufacturing a patterned retarder using a polarizing pulse UV will be described with reference to FIGS. 1 to 2C.

Substrate preparation step ( S10 ):

A substrate 10 for forming a multi-domain on the surface is prepared. The substrate 10 can be selected according to various standards as required, and is formed of a transparent insulating substrate such as a glass substrate, a film, and a flexible substrate. In this case, the film may be made of a material selected from the group consisting of tri-acetate cellulose (TAC), cyclo olefin polymer (COP), cyclic olefin copolymer (COC), poly vinyl alcohol (PVA), polycarbonate (PC), poly methyl methacrylate (PMMA), polyethylene terephthalate ), PEN (polyethylene naphthalate), PES (polyethersulfone), PS (polystyrene), PI (polyimide), polyarylate, and PEEK (polyetheretherketone).

Meanwhile, the substrate 10 may include a photo-mask 40 for forming a multi-domain pattern.

The photoreactive layer  Formation step ( S20 ):

As shown in FIG. 2A, a photoreactive layer 20 is formed by applying a photoreactive agent to the surface of the prepared substrate 10. Herein, the photoreactive agent may be at least one selected from the group consisting of polyimide, polyvinyl, polysiloxane, poly (vinylidene fluoride), poly And may be made of a polyacrylic material.

Polarized pulse UV  Multi domain formation step by irradiation ( S30 ):

The photoactive layer 20 on the substrate 10 is irradiated with a polarizing pulse UV to form a photo alignment layer 30 in which stripe type first domain 31 and second domain 32 alternate with each other, . At this time, the first domain 31 is oriented in a first direction by a polarized pulse UV polarized in a first direction (e.g., 0 占 and the second domain 32 is oriented in a second direction Is polarized in the second direction by the polarized pulse UV.

According to an embodiment of the present invention, first, as shown in FIG. 2B, a polarizing pulse UV polarized in a first direction is applied to the entire area of the photoreactive layer 20 so that the photoreactive layer 20 moves in the first direction To form a first domain 31 having a photo-aligned state.

Next, as shown in FIG. 2C, a photo-mask 40 having a light transmission area TA and a blocking area BA is placed on the substrate 10, The polarizing pulse UV polarized in the second direction from above is radiated perpendicularly to the substrate 10. At this time, in the photoresponsive layer 20 constituting the first domain 31, a region corresponding to the transmissive region TA of the photomask 40 is partially exposed and the second domain having a photo-oriented state in the second direction (32).

That is, the photoreactive layer 20 is exposed to the first domain 31 in the first direction and the second domain 32 in the second direction through the front exposure step and the partial exposure step with the polarizing pulse UV Thereby forming the optical alignment layer 30 alternately continuous.

The first domain 31 and the second domain 31 having different orientations in the photo alignment layer 30 are formed by the front exposure of the photoreactive layer 20 and the partial exposure using the photomask 40 32 are formed. However, the method of forming the multi-domain photo-alignment layer 30 may be variously performed.

For example, a first photomask is formed by using a first photomask in which a region corresponding to the first domain 31 is a transmissive region TA and a region corresponding to the second domain 32 is a blocking region BA, After the exposure, a second photomask is formed by using a second photomask in which the region corresponding to the first domain 31 is the blocking region BA and the region corresponding to the second domain 32 is the transmissive region TA, A multi-domain can also be formed by exposure.

In contrast to the embodiment shown in Figs. 2B and 2C, there is also a method of first forming the first domain 31 by partial exposure, and then forming the second domain 32 by front exposure.

However, the method of forming the multi-domain using the first photomask and the second photomask has a lower processability than that of the embodiment shown in FIGS. 2B and 2C, and the method of forming the multi-domains by the whole exposure after the partial exposure The orientation is lower than the embodiment shown in Figs. 2B and 2C. This will be described later with reference to Figs. 17 to 20.

FIG. 3 compares the peak power and the irradiation time when the normal UV and the pulse UV are irradiated with the same energy of 1200 Watt-seconds.

A method of manufacturing a patterned retarder using a polarizing pulse UV according to an embodiment of the present invention is characterized by using a polarizing pulse UV in exposure for forming a multi-domain.

That is, in the conventional photo alignment method, UV (Ultra Violet) having a constant energy is continuously irradiated for a predetermined period of time. In the present invention, UV having a high energy is irradiated in a pulse form. These pulsed UVs are only irradiated for a very short time and are cooled for a relatively long time. That is, the UV irradiation time is short and the cooling time is long as a whole because the duty cycle (the time at which the pulse is turned on / the total time at which the pulse is repeated × 100 (%)) has a very small value of less than 1% There is an advantage that heat is not generated during the pulse UV irradiation process.

Referring to FIG. 3, a typical UV with a peak power of 10 Watts is irradiated for 120 seconds, while a pulse having a pulse width of 1 millisecond and a peak power of 100,000 Watts The UV is irradiated with 12 pulses (multiple pulses) for 12 seconds, and the pulse UV with a pulse width of 3 milliseconds and a peak power of 400,000 Watts is irradiated with one (single pulse) pulse. That is, the pulse UV can irradiate the same energy in a very short time compared with the general UV.

According to one embodiment of the present invention, the polarizing pulse UV can be irradiated with a pulse width of 20 microseconds or less and a waveform of 1 to 60 Hz per second with a pulse width of 0.1 mJ / pulse to 500 J / pulse, It is possible to shorten the processing time by shortening the irradiation time and to improve the productivity by this. At this time, the flash voltage of the polarizing pulse UV is preferably 1 kV to 4 kV, and the exposure time is preferably 0.1 second to 10.0 second.

On the other hand, the luminous intensity of the luminescent lamp at the point corresponding to the center of the lamp and the peripheral portion thereof becomes more significant as the distance from the surface of the object increases. Therefore, the intensity and uniformity of the UV light emitted from the UV lamp at the time of light distribution are better as the distance is closer to the substrate, but in the conventional case, the minimum exposure distance has to be maintained due to thermal deformation directly received by the substrate. Generally, an exposure distance of about 10 to 15 cm is secured. In this case, the uniformity of the central portion and the peripheral portion of the UV light irradiated to the substrate is about 30%.

However, in the case of irradiating the pulsed UV according to an embodiment of the present invention, since heat generation is almost insignificant, the surface of the substrate is not thermally affected, and therefore, by irradiating the pulsed UV as close as possible to the surface of the substrate, The uniformity can be maintained at almost 100%. According to an embodiment of the present invention, the exposure distance of the polarizing pulse UV is preferably 0.5 cm to 10.0 cm.

In addition, since the polarizing pulse UV irradiates an instantaneous pulse wave at the initial time, it has a strong penetrating power at the time of light distribution. As a result, the polarizing pulse UV can uniformly orient the thick layer of the photoreactive layer evenly.

In terms of cost, the use of a polarized pulse UV lamp can reduce the power consumption by 80% or more as compared with the case of using a conventional arc discharge UV lamp. Because the polarization pulse UV uses instantaneous UV energy, the power consumption is reduced.

In addition, since the polarizing pulse UV can instantaneously turn on / off the function, the UV lamp can be turned off when the UV irradiation is not required in the process flow, so that the energy saving effect is achieved and a separate opening and closing device such as a shutter is not required . In addition, since there is no need to replace consumables such as a cold mirror and a hot mirror, which are used for conventional light conversion using general UV, there is an advantage in terms of economy.

General polarization UV And a polarizing pulse UV  Depending on the exposure time Orientation  compare

A liquid crystal cell was prepared and used as follows to compare the alignment properties according to the respective exposure times in the case of forming a photo alignment layer by irradiation with normal UV and the case of forming a photo alignment layer by irradiation with a pulse UV.

First, a glass substrate or a triacetate (TAC) substrate was used as a substrate, and a photoreactive material dissolved in a 1% MEK / toluene organic solvent was coated on a substrate to form a photoreactive layer / RTI >

Then, the photo-reactive layer was irradiated with the general polarized UV and the polarized pulse UV at an exposure distance of 7 cm for 0.1 second to 0.4 second, respectively, to form a photo alignment layer on the substrate. The reactive liquid crystal was dissolved in a 12% toluene organic solvent, And dried.

At this time, the general polarized UV was irradiated at a power density of 10.5 mW / cm 2, and the polarized pulse UV was irradiated at a flash voltage of 3 kV and a frequency of 50 Hz.

FIG. 4 is a polarized optical microscope (POM) photograph according to the exposure time of the general UV and pulse UV, and FIG. 5 is a graph comparing the micro-orientation distribution of the photo alignment layer with the exposure time of the general UV and the pulse UV And FIG. 6 is a graph comparing changes in retardation of the photo alignment layer with exposure time of general UV and pulse UV.

As shown in FIG. 4, as the exposure time increases in both the case of irradiating with the general polarized UV and the case of irradiating with the polarizing pulse UV, the black image and the white image are clearly visible .

However, as shown in FIG. 5, in the case of irradiation with the general polarized UV, the field distribution is lowered to 1% or less when the exposure time reaches 0.4 seconds, whereas when the polarized pulse UV is irradiated, The orientation distribution degree dropped to 1% or less. At this time, as shown in FIG. 4, the black image and the white image were clear.

That is, in the case of forming the photo alignment layer by irradiating the polarizing pulse UV according to an embodiment of the present invention, it is understood that the photo alignment process time is reduced by about 50% by the improvement of the photo alignment speed.

In addition, according to the general polarized UV, the exposure energy is 5.0 mJ / cm 2 for 0.4 second until the degree of the unoriented distribution becomes 1% or less, while the polarizing pulse UV is irradiated according to the embodiment of the present invention, The exposure energy of 3.2 mJ / cm 2 was required for 0.2 second. Therefore, according to the embodiment of the present invention, the exposure energy saving effect is about 36% as compared with the conventional case.

6 shows that the retardation converges to a certain range (for example, 125 nm +/- 10 nm) within a shorter time when the polarizing pulse UV is used, as compared with the case of using the general polarized UV, .

Polarized pulse UV  When using At the exposure distance  Following Orientation  compare

In order to compare the alignment properties according to the exposure distance in the case of forming the photo alignment layer by irradiating the polarizing pulse UV, the following liquid crystal cell was prepared and used.

First, a glass substrate or a triacetate (TAC) substrate was used as a substrate, and a photoreactive material dissolved in a 1% MEK / toluene organic solvent was coated on a substrate to form a photoreactive layer / RTI >

Then, the photo-reactive layer was formed by irradiating the photo-reactive layer with a polarizing pulse UV under a severe condition of exposure time of 0.1 sec while varying the exposure distance by 1.5 cm, 3 cm, 4 cm, and 7 cm, respectively. The reactive liquid crystal was immersed in 12% Dissolved in a solvent, and dried.

At this time, the polarizing pulse UV was irradiated with a flash voltage of 3 kV and a frequency of 50 Hz.

FIG. 7 is a photograph of a polarized light microscope according to the exposure distance of the polarizing pulse UV, and FIG. 8 is a graph showing a micro-orientation distribution diagram of the photo alignment layer according to the exposure distance of the polarizing pulse UV.

As shown in FIGS. 7 and 8, the closer the exposure distance between the UV lamp that irradiates the polarizing pulse UV and the exposure surface (the photoreactive layer), the smaller the micro-orientation distribution and the clearer the black image and the white image. On the other hand, as the exposure distance increases, the sharpness of the black image and the white image decreases as the distribution of the unidirectional orientation increases. When the exposure distance exceeds 7 cm, the variation of the unidirectional distribution with the exposure distance increases is small.

FIG. 9 is a graph showing the phase difference change of the photo alignment layer according to the exposure distance of the polarizing pulse UV, and it can be seen that the phase difference decreases with a certain slope as the exposure distance increases.

Polarized pulse UV  When using flash by voltage, by frequency Orientation  compare

In the case of forming the photo alignment layer by irradiating the polarizing pulse UV, a liquid crystal cell was prepared and used as follows to compare the orientation of the polarized pulse UV light with respect to the flash voltage and frequency.

First, a glass substrate or a triacetate (TAC) substrate was used as a substrate, and a photoreactive material dissolved in a 1% MEK / toluene organic solvent was coated on a substrate to form a photoreactive layer / RTI >

Thereafter, the photo-reactive layer was irradiated with a polarizing pulse UV at an exposure time of 0.2 seconds and an exposure distance of 1.5 cm to form a photo alignment layer. The reactive liquid crystal was dissolved in a 12% toluene organic solvent and applied and dried. At this time, the flash voltage of the polarizing pulse UV was set to 2.0 kV, 2.5 kV, and 3.0 kV, respectively, and polarized pulse UVs of 1 Hz, 20 Hz, 30 Hz, 40 Hz, and 50 Hz frequencies were irradiated from the respective flash voltages.

Fig. 10 is a photograph of a polarized light microscope by frequency and frequency of a pulse UV at an exposure distance of 1.5 cm, Fig. 11 is a graph showing micro-orientation distribution of a photo- And FIG. 12 is a graph comparing changes in phase difference of the photo-alignment layers by the flash voltage and the frequency at the exposure distance of 1..5 cm.

FIGS. 10 and 11 show that as the frequency of the polarizing pulse UV increases, and as the flash voltage of the polarizing pulse UV increases, the non-oriented distribution decreases and a black image appears clearly.

Also, FIG. 12 shows that as the flash voltage of the polarizing pulse UV increases, the orientation can be achieved at a lower frequency.

In particular, when the frequency of the polarized pulse UV is 40 Hz or higher, the unidirectional distribution is less than 1% at the flash voltage of 2.0 kV. When the flash voltage is 3 kV, the unidirectional distribution is less than 1% at the frequency of 20 Hz. That is, when the flash voltage of the polarizing pulse UV is 3 kV, the optimum black image is realized at the frequency of 20 Hz and the unbalanced distribution is the minimum. When the flash voltage of the polarizing pulse UV is 2.0 kV and 2.5 kV, Image implementation and unoriented distribution were minimized.

FIG. 13 is a photograph of a polarized light microscope by frequency and frequency of the pulse UV at an exposure distance of 7.0 cm, FIG. 14 is a photograph of the microvolume of the pulse UV at the exposure distance of 7.0 cm, And FIG. 15 is a graph comparing changes in the phase difference of the photo-alignment layer with respect to the pulse voltage and the frequency of the pulse UV at an exposure distance of 7.0 cm.

Referring to FIGS. 13 to 15, when the exposure distance is increased from 1.5 cm to 7.0 cm, when the flash voltage of the polarizing pulse UV is 3 kV, it is optimum at a frequency of 20 Hz, and when the flash voltage is 2.5 kV, It can be confirmed that the image is implemented. In addition, when the exposure distance is set to 7 cm, the unevenness distribution as a whole is increased as compared with the above-described experimental example in which the exposure distance is 1.5 cm. This is due to an increase in light leakage in the outer portion of the liquid crystal cell as the exposure distance increases.

General polarization UV And a polarizing pulse UV  When using Pretilt angle ( pretilt angle ) compare

In order to compare the pretilt angles with the respective exposure times in the case of forming the photo alignment layer by irradiating general UV and the case of forming the photo alignment layer by irradiating the pulse UV, a liquid crystal cell is prepared and used as follows Respectively.

First, a glass substrate or a triacetate (TAC) substrate was used as a substrate, and a photoreactive material dissolved in a 1% MEK / toluene organic solvent was coated on a substrate to form a photoreactive layer / RTI >

Then, the photo-reactive layer was irradiated with the general polarized UV and the polarizing pulse UV at an exposure distance of 7 cm for 0.1 second to 0.4 second, respectively, to form a photo alignment layer. The liquid crystal layer was formed by a twisted nematic (TN) liquid crystal Respectively.

At this time, the general polarized UV was irradiated at a power density of 10.5 mW / cm 2, and the polarized pulse UV was irradiated at a flash voltage of 3 kV and a frequency of 50 Hz.

16 is a graph comparing the pretilt angles of the general polarized UV and the pulsed polarized UV according to the exposure time. As shown in FIG. 16, the pretilt angle tends to decrease with increasing exposure time, both in the case of irradiation with the general polarized UV and in the case of irradiation with the polarizing pulse UV.

However, in the case of exposure by the polarizing pulse UV, the pretilt angle is lower than that in the case of exposure by the general polarized UV, and the pretilt angle converges to a constant value when the exposure time is 0.2 second in the case of the polarizing pulse UV Orientation, whereas in the case of general polarized UV, the alignment is observed after an exposure time of 0.4 second. That is, in the case of using the polarizing pulse UV according to an embodiment of the present invention, superior horizontal alignment can be realized with less energy.

Polarized pulse UV  Depending on the method of forming multi-domains in exposure Orientation  compare

In order to compare the orientations according to the method of forming the multi-domains in the polarizing pulse UV exposure, the multi-domains were formed by the following three different methods.

In this case, a glass substrate or triacetate (TAC) substrate was used as the substrate, and a photoreactive material dissolved in a 1% MEK / toluene organic solvent was coated on the substrate to form a photoreactive layer / RTI >

In addition, the exposure for forming the multi-domain was performed by polarized pulse UV irradiation with a flash voltage of 3 kV, a frequency of 50 Hz, and an exposure distance of 7 cm, and then the reactive liquid crystal was dissolved and dissolved in a 12% toluene organic solvent.

Case  One

First, the photoreactive layer is firstly exposed using a first photomask having a region corresponding to the first domain as a transmissive region and a region corresponding to the second domain as a blocking region, The multidomain was formed by secondary exposure using a second photomask having a corresponding region as a blocking region and a region corresponding to the second domain as a transmissive region. At this time, the first domain is formed by the primary exposure to irradiate the polarized pulse UV in the first direction and the second domain is formed by the secondary exposure to irradiate the polarized pulse UV polarized in the second direction.

Case  2

First, the entire surface of the photoreactive layer is irradiated with a polarizing pulse UV polarized in a first direction to perform a first front exposure, and then a region corresponding to the first domain is set as a blocking region and a region corresponding to the second domain Domain was exposed using a photomask having a region as a transmissive region to form a multi-domain. At this time, the first domain is formed by the first-order front exposure that irradiates the polarized pulse UV in the first direction and the second domain is formed by the second-order partial exposure which irradiates the polarized pulse UV which is polarized in the second direction do.

Case  3

The third method was performed in the reverse order of the second method. First, the first domain was formed by the first partial exposure, and then the second domain was formed by the second front exposure. That is, first, the photoreactive layer is first partially exposed using a photomask having a region corresponding to the first domain as a transmissive region and a region corresponding to the second domain as a blocking region, The entire surface area of the formed photoreactive layer was subjected to the second whole surface exposure to form the second domain. At the time of the first partial exposure, the polarized pulse UV polarized in the first direction is irradiated to the photoreactive layer through the photomask. In the second frontal exposure, the polarized pulse UV polarized in the second direction is partially incident on the first domain The total area of the formed photoreactive layer was examined.

FIG. 17 is a polarized light microscope photograph showing a comparison of alignment properties according to the 0 ° / 45 ° multi-domain formation method in polarized pulse UV exposure.

The first and second domains were irradiated with a polarizing pulse UV on the photoreactive layer by the above-mentioned three methods, and the result was observed with a polarizing optical microscope. As a result, all of the three methods were stripe-type The black image and the white image appeared alternately sharp. This indicates that a multi-domain including the first domain and the second domain is formed in the photo alignment layer, and thus it is possible to manufacture the patterned retarder by using the polarizing pulse UV in the exposure process.

FIG. 18 is a graph comparing orientations according to a 0 ° / 45 ° multi-domain formation method in polarized-pulse UV exposure, and shows an orientation angle? According to exposure time. At this time, the orientation angle [theta] shown in the drawing indicates the angle between the liquid crystal optical axis aligned by the primary exposure and the liquid crystal optical axis aligned by the secondary exposure, the exposure time in the front exposure was 0.2 seconds, The exposure time was 0.2 seconds to 1.4 seconds.

In the case of the second method (Case 2), the orientation angle (?) Increases with an increase in the second partial exposure time, and the orientation angle (?) Is 45 degrees when the exposure time is 0.8 seconds. That is, the exposure time and the exposure energy in the secondary partial exposure are preferably larger than the exposure time and the exposure energy in the primary front exposure. In the second method (Case 2), the first front exposure time is 0.2 second, the second partial exposure time is 0.8 second, and the second partial exposure time is 0.8 second. It can be seen that the orientation is most excellent.

In the case of the third method (Case 3), the orientation angle (?) Increases as the first partial exposure time increases, and then the orientation angle (?) Decreases as the first partial exposure time exceeds 0.8 seconds have. That is, in the case of the third method (Case 3), the best orientation is obtained when the first partial exposure time is 0.8 second and the second general exposure time is 0.2 second. However, in the case of the third method (Case 3), since the orientation angle (θ) is less than 45 ° regardless of the exposure time, the orientation is less than that of the second method (Case 2) .

In addition, in the case of the first method (Case 1), it is shown that the 45 ° orientation is achieved by the 0.2 second primary exposure and the 0.2 second secondary exposure, but the first photomask and the second photomask are separately prepared and managed Since the first photomask and the second photomask are appropriately replaced during the exposure process, there is a problem that the processability is lower than the second method (Case 2) and the third method (Case 3).

The second method (Case 2) is superior to the first method (Case 1) and the third method (Case 3) in consideration of the orientation and fairness.

Figure 19 is a polarized light micrograph of polarized light UV exposure comparing alignment in accordance with the 0 ° / 90 ° multi-domain formation method and Figure 20 shows the orientation in accordance with the 0 ° / 90 ° multi-domain formation method during polarized pulse UV exposure FIG.

Even when the orientation angle [theta] is changed by 90 [deg.], The results as described above are shown with reference to Figs. 17 and 18. [

The second method (Case 2) showed the best results when the orientation and fairness were taken into consideration. The second method (Case 2) showed the best orientation at 0.2 sec for the first front exposure time and 0.8 sec for the second partial exposure time .

On the other hand, various applications can be manufactured by the pattern-reliader manufacturing method using the polarizing pulse UV as described above. For example, by irradiating a polarizing pulse UV onto a photoreactive layer formed on a substrate, a photo alignment layer optically aligned in at least one direction can be obtained, and a liquid crystal display including such a photo alignment layer can be manufactured.

(For example,? / 4 or? / 2 phase difference film, polarizing film and the like) having a photo alignment film formed by polarized pulse UV irradiation can be manufactured. It is also possible to manufacture.

10: substrate
20: Photoreactive layer
30: photo alignment layer
31: First domain
32: second domain
40: Photomask

Claims (13)

(a) preparing a substrate;
(b) forming a photoreactive layer by applying a photoreactive agent on the substrate; And
(c) exposing the photoreactive layer to form a photo alignment layer in which stripe-type first domains and second domains alternate with each other, the method comprising the steps of:
Characterized in that the first domain is optically oriented in a first direction by a polarization pulse UV and the second domain is optically oriented in a second direction by a polarization pulse UV,
The step (c)
(c-1) irradiating the photoreactive layer with a polarized pulse UV polarized in a first direction to perform front exposure; And
(c-2) irradiating the photoreactive layer with a polarized pulse UV polarized in a second direction, blocking a region corresponding to the first domain using a photomask, and removing only a region corresponding to the second domain Comprising the steps of:
The polarizing pulse UV has an energy of 0.1 mJ / pulse to 500 J / pulse,
And the exposure time by the polarizing pulse UV is 0.1 sec to 10.0 sec.
delete The method according to claim 1,
(d) coating and drying the reactive liquid crystal on the secondarily exposed photo alignment layer, and then curing the liquid crystal layer.
delete The method according to claim 1,
Wherein the polarizing pulse UV is irradiated at a frequency of 1 Hz to 60 Hz.
The method according to claim 1,
And the flash voltage of the polarizing pulse UV is 1 kV to 4 kV.
delete The method according to claim 1,
Wherein the exposure time and the exposure energy in the step (c-2) are greater than the exposure time and the exposure energy in the step (c-1).
The method according to claim 1,
And the exposure distance by the polarizing pulse UV is 0.5 cm to 10.0 cm.
A photo-alignment film produced by the method according to any one of claims 1, 3, 5, 6, 8 and 9.
A liquid crystal display characterized by being manufactured by the method according to any one of claims 1, 3, 5, 6, 8 and 9.
An optical film produced by the method according to any one of claims 1, 3, 5, 6, 8, and 9.
A 3D display lens characterized by being manufactured by the method according to any one of claims 1, 3, 5, 6, 8 and 9.

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