KR100793039B1 - A manufacturing apparatus of polarizer employed in the backlight unit and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for manufacturing a polarizer for use in a backlight device. Method of manufacturing a polarizer used in the backlight device of the present invention is the step of applying a UV resin (UV Resin) on the base film moving on the conveyor belt and a lens having a specific focal length of the ultraviolet light on the UV resin coated base film Irradiating through to form a plurality of lines having a predetermined interval. The manufacturing apparatus and method of the polarizer may pass through ultraviolet light through a lens to irradiate the UV resin to form a line of a predetermined interval to produce a polarizer to perform the role of a thin film multilayer reflective polarizing film.

Backlight device, polarizer, partial curing

Description

A manufacturing apparatus and method for a polarizer used in a backlight device {A MANUFACTURING APPARATUS OF POLARIZER EMPLOYED IN THE BACKLIGHT UNIT AND MANUFACTURING METHOD THEREOF}

1 is a cross-sectional view illustrating a liquid crystal display device using a backlight device according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of the backlight device of FIG. 1.

3 is a perspective view illustrating the polarizer of FIG. 2.

4 is a cross-sectional view schematically showing an apparatus for manufacturing a polarizer according to an exemplary embodiment of the present invention.

5 is a cross-sectional view showing a UV resin coating device of the manufacturing apparatus of FIG.

6A is a cross-sectional view illustrating a UV resin curing apparatus of the manufacturing apparatus of FIG. 4.

6B and 6C are cross-sectional views illustrating a process of curing the UV resin by the UV resin curing apparatus of FIG. 6A.

7 is a cross-sectional view illustrating a polarizer after being washed and dried by a washing apparatus and a drying apparatus of the manufacturing apparatus of FIG. 4.

The present invention relates to a manufacturing apparatus and method of a polarizer used in a backlight device, and more particularly to a manufacturing apparatus and method for manufacturing a polarizer capable of performing the role of a thin film multilayer reflective polarizing film.

In general, a liquid crystal display device (hereinafter referred to as an "LCD device") is an electronic device that transmits various electrical information generated by various devices to visual information by using a change in liquid crystal transmittance according to an applied voltage. Element.

Since the LCD element is a display element of various information and does not have its own light emitting source, a separate device is required to lightly illuminate the entire screen of the LCD element by placing a light source on the back side thereof. Back Light Unit (hereinafter referred to as "BLU").

The backlight device includes a mold frame in which a storage space is formed, a reflective sheet disposed on a bottom surface of the storage space to reflect light toward the liquid crystal display panel, a light guide plate disposed on the reflective sheet on an upper surface thereof, and guiding the light; And a light source disposed between sidewalls of the storage space to emit light, optical sheets stacked on an upper surface of the light guide plate to diffuse and collect light, and an upper portion of the mold frame to define an edge portion of the liquid crystal display panel. It consists of a top chassis covering from to the side of the mold frame.

At this time, the upper and lower portions of the liquid crystal display panel are each provided with a polarizing plate that transmits only a specific polarization of the incident light and absorbs the remaining polarization, and the light passing through each polarizing plate has a phase difference of 90 degrees with each other. do.

In addition, the optical sheets include a diffusion sheet for diffusing light, a prism sheet for condensing the light diffused and stacked on an upper surface of the diffusion sheet, and transferring the light to a liquid crystal display panel, and a protective sheet for protecting the diffusion sheet and the prism sheet. It consists of.

In the case of the LCD device having the above configuration, the intensity of the light emitted from the first light source is gradually canceled through the light guide plate and the optical sheets until the light is finally incident to the liquid crystal display panel, so that the luminance displayed on the screen is substantially reduced. There is a problem that is reduced to a few hundredths.

That is, the recent trend is that a display device of high brightness is required, and the backlight device structure does not support such a recent trend.

One way to overcome this has been to use a protective sheet provided on the prism sheet as a thin multi-layer reflective polarizer film.

The thin film multilayer reflective polarizing film functions to increase the transmission efficiency of specific polarized light transmitted by the lower polarizing plate provided under the liquid crystal display panel among the light passing through the prism sheet.

That is, the thin film multilayer reflective polarizing film transmits a specific polarized light from the light passing through the prism sheet, reflects the other polarized light, and the reflected light is re-reflected by a reflective sheet or the like and converted into unpolarized light, and then the thin film multilayer It is to serve to increase the amount of light passing through the lower polarizing plate to be incident on the reflective polarizing film.

In this case, the specific polarized light is a polarized light transmitted through the lower polarizing plate, and may be a longitudinal wave (P wave) or a transverse wave (S wave), and other polarizations become transverse wave (S wave) or longitudinal wave (S wave), respectively. .

Through this, the conventional backlight device may reuse the polarized light discarded to achieve an overall brightness enhancement effect.

Meanwhile, the thin film multilayer reflective polarizing film is made by stacking transparent materials having different refractive indices in multiple layers. However, the thin film multilayer reflective polarizing film has a disadvantage in that the transmission efficiency of a specific polarization and the reflection efficiency of the other polarizations are not so high. The wire grid polarizer developed by irradiating a polarized pulsed laser beam was developed to improve the shortcomings of the thin film multilayer reflective polarizing film, which is well shown in Korean Application No. 2005-0040544.

On the other hand, the grating polarizer forms a metal thin film on the transparent film, and irradiated with a polarized pulse laser beam to form a metal pattern having a fine gap.

However, since the gap should be formed in fine units, it was difficult to accurately pattern it on the transparent film. In addition, since the process of patterning the glass substrate is difficult, the time required to manufacture one reflective polarizer is long, and mass production is difficult.

Therefore, there is a need for manufacturing a reflective polarizer in a convenient manner.

An object of the present invention is to form a line at a predetermined interval by passing ultraviolet rays through a lens to irradiate the UV resin, the polarizer of the polarizer used in a backlight device capable of manufacturing a reflective polarizer to serve as a thin film multilayer reflective polarizing film It is to provide a manufacturing apparatus and method.

It is also an object of the present invention to provide an apparatus and method for manufacturing a polarizer for use in a backlight device which can be mass-produced and shorten manufacturing time.

In order to achieve the object as described above, the manufacturing method of the polarizer used in the backlight device according to an embodiment of the present invention is the step of applying a UV resin (UV Resin) on the base film moving on the conveyor belt and the UV Irradiating the base film coated with the resin with ultraviolet rays through a lens having a specific focal length to form a plurality of lines having a predetermined interval.

In addition, the manufacturing apparatus of the polarizer according to the present invention is a UV resin coating device for applying a UV resin to a predetermined thickness on the first conveyor belt for moving the base film, the base film moving on the first conveyor belt and the UV resin is applied It is characterized in that it comprises a UV resin curing device for curing the UV resin to form a line of a predetermined interval by irradiating ultraviolet rays through a lens having a specific focal length to the base film.

The apparatus and method for manufacturing a polarizer used in the backlight device may produce a reflective polarizer that serves as a thin film multilayer reflective polarizer by forming ultraviolet rays through a lens and irradiating UV resin to form a line at a predetermined interval. .

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the manufacturing apparatus and method of the polarizer used in the backlight device according to the present invention.

1 is a cross-sectional view illustrating a liquid crystal display device using a backlight device according to an exemplary embodiment of the present invention, FIG. 2 is a cross-sectional view of the backlight device of FIG. 1, and FIG. 3 is a perspective view of the polarizer of FIG. 2. to be.

Referring to FIG. 1, a liquid crystal display device (hereinafter referred to as an “LCD device”) includes a liquid crystal panel (LC panel) 200 and a backlight device 202.

The LC panel 200 includes a lower polarizing film 204, an upper polarizing film 206, a lower substrate 208, an upper substrate 210, a color filter 212, a black matrix 214, a pixel electrode 216, The common electrode 218, the liquid crystal layer 220, and the TFT array 222 are included.

The color filter 212 includes color filters corresponding to red, green, and blue, and generates an image corresponding to red, green, or blue when light is applied.

The TFT array 222 switches the pixel electrode 216 as a switching element.

The common electrode 218 and the pixel electrode 216 arrange molecules of the liquid crystal layer 220 according to a predetermined voltage applied from the outside.

The liquid crystal layer 220 is composed of predetermined molecules, and the molecules are arranged corresponding to the voltage difference between the pixel electrode 216 and the common electrode 218.

As a result, light provided from the backlight device 202 below is incident on the color filter 212 corresponding to the molecular arrangement of the liquid crystal layer 220.

A back light unit (hereinafter referred to as "BLU") 202 is located under the LC panel 200 and provides light, for example, white light, to the LC panel 200.

Referring to FIG. 2, the BLU 202 may include a light source unit 300, a light guide plate 310, a reflective sheet 320, and an optical film 330.

The light source unit 300 is located at the side of the BLU 202 and includes one or more light sources 302 and a light source reflector 304.

The light source 302 is formed of an aggregate of one or more Cold Cathode Fluorescent Lamps (CCFLs). Preferably, two light sources 302 positioned adjacent to both ends of the light guide plate 310 are used.

The CCFL provides very bright white light.

The light source 302 may be a light emitting diode (LED) or an external electrode fluorescent lamp (EEFL) in addition to the CCFL.

The LED can be composed of red, green and blue or a single color of white light. In the case of the BLU 202 using the LED as a light source, it is possible to maintain the uniformity of the light while miniaturizing the BLU 202 and improving the light efficiency.

The EEFL has a higher luminance than the CCFL and is advantageous in that the electrode is external to operate in parallel. In particular, the EEFL can reduce the number of inverters required by the conventional light source, thereby reducing the cost of components and the weight of the LCD device.

The light source reflector 304 surrounds the light source 302 and is intended to improve light efficiency by allowing light emitted from the light source 302 to enter the side of the light guide plate 310. To this end, the light source reflector 304 is made of a highly reflective material, and may coat silver (Ag) on its surface.

The reflective sheet 320 is positioned below the light guide plate 310 to reflect light from the light source 302 to the front surface of the light guide plate 310. Reflective sheet 320 according to an embodiment of the present invention is coated on a silver (silver) on a sheet made of SUS, Brass, aluminum, PET and the like, even if the heat is generated fine titanium coating to prevent deformation due to endothermic long time Can be produced. In addition, the reflective sheet 320 according to another embodiment of the present invention may be manufactured by dispersing bubbles for scattering light on a sheet made of synthetic resin such as PET.

The light guide plate 310 is designed such that continuous total reflection occurs at or above a critical angle after light is incident on the side surface. Since the light source 302 is located on the side of the BLU 202, the light generated from the light source 302 is concentrated at the edges rather than uniformly transmitted over the front of the BLU 202. Therefore, the light guide plate 310 is required to uniformly transmit the light to the front surface. The light guide plate 310 is generally made of a transparent acrylic resin such as polymethyl methacrylate (hereinafter referred to as "PMMA"). The PMMA is characterized by high strength, low cracking, low deformation, and high visible light transmittance.

In addition, the light guide plate 310 propagates light toward the LC panel 200.

The optical film 330 includes a diffusion sheet 332, a prism sheet 334, a protective sheet 336, and a reflective polarizer 338.

Light uniformly diffused in the light guide plate 310 passes through the diffusion sheet 332. The diffusion sheet 332 widens the viewing angle.

The light passing through the diffusion sheet 332 is sharply reduced in brightness, the prism sheet 334 is used to prevent this.

The prism sheet 334 collects some of the light propagated from the light guide plate 310 toward the protective sheet 336 and reflects the remaining light toward the diffusion sheet 332 using the reflective liquid crystals. Accordingly, most of the light passing through the prism sheet 334 runs perpendicular to the plane of the LC panel 200 to have a uniform luminance distribution.

The protective sheet 336 is positioned on the prism sheet 334 to prevent scratches of the prism sheet 334 and to widen the viewing angle narrowed by the prism sheet 334.

As illustrated in FIG. 3, the reflective polarizer 338 has a plurality of lines 410 patterned on the base film 400.

The plurality of lines 410 have a constant spacing, preferably, the spacing between the lines 410 is 200 nm or less. Lines 410 are formed by curing the UV resin. UV resins are polymer blends containing special ingredients that are sensitive to UV (ultraviolet) radiation. Preferably, lines 410 are formed by including a metal material such as Ag or Al in the UV resin.

The reflective polarizer 338 reflects some of the light diffused by the protective sheet 336 in the direction of the light guide plate 310, and provides the remaining light to the LC panel 200.

For example, the reflective polarizer 338 transmits a longitudinal wave (P wave) of light diffused by the protective sheet 336, and the transverse wave (S wave) reflects in the direction of the light guide plate 310.

The transverse wave reflected by the reflective polarizer 338 is reflected back by the light guide plate 310 or the reflective sheet 320.

In this case, due to the physical properties of the light, the re-reflected light includes longitudinal and transverse waves.

That is, the transverse wave reflected by the reflective polarizer 338 is changed to light including the transverse wave and the longitudinal wave by being reflected back by the light guide plate 310 or the reflective sheet 320.

Subsequently, the changed light passes through the diffusion sheet 332, the prism sheet 334, and the protective sheet 336 and is incident back to the reflective polarizer 338.

As a result, the longitudinal wave of the changed light passes through the reflective polarizer 338, and the transverse wave is reflected toward the light guide plate 310.

Subsequently, the reflected light is again reflected by the light guide plate 310 or the reflective sheet 320 to be converted into light including longitudinal waves and transverse waves.

The BLU 202 repeats this process to improve the efficiency of the light.

Hereinafter, the light emission operation of the LCD element will be described in detail.

Referring back to FIG. 1, the BLU 202 provides the LC panel 200 with plane light that is white light.

Subsequently, the TFT array 222 switches the pixel electrode 216.

Subsequently, a predetermined voltage difference is applied between the pixel electrode 216 and the common electrode 218, so that the liquid crystal layer 220 is arranged corresponding to the red color filter, the green color filter, and the blue color filter, respectively.

In this case, the amount of light is adjusted while the plane light provided from the BLU 202 passes through the liquid crystal layer 220, and the plane light whose light amount is adjusted is provided to the color filter 212.

As a result, the color filter 212 implements an image with a predetermined gray scale.

In detail, the red color filter, the green color filter, and the blue color filter form one pixel, and the pixels implement a predetermined image by a combination of light passing through the red color filter, the green color filter, and the blue color filter. do.

Hereinafter, the manufacturing apparatus and manufacturing process of the reflective polarizer 338 used for the BLU 202 are explained in full detail.

4 is a cross-sectional view schematically showing a manufacturing apparatus of a polarizer according to an embodiment of the present invention, Figure 5 is a cross-sectional view showing a UV resin coating apparatus of the manufacturing apparatus of Figure 4, Figure 6a is a manufacturing of FIG. Figure 6 is a cross-sectional view showing a UV resin curing device of the device, Figure 6b and 6c is a cross-sectional view showing the process of curing the UV resin by the UV resin curing device of Figure 6a, Figure 7 is a cleaning device of the manufacturing apparatus of Figure 4 And a polarizer after being washed and dried by a drying apparatus.

Referring to FIG. 4, the apparatus for manufacturing a reflective polarizer according to the present invention includes a first conveyor belt 500, a UV resin coating device 510 to be described later, a UV resin curing device 520, a washing device, and a drying device. do.

The first conveyor belt 500 moves the base film 400 for manufacturing the reflective polarizer 338 at a constant speed and transmits the same to each manufacturing apparatus.

The base film 400 is wound in the shape of a roll on one end of the first conveyor belt 500. The base film 400 wound on the roll is introduced into the first conveyor belt 500 while one end of the base film 400 is unwinded as the first conveyor belt 500 moves.

The base film 400 introduced into the first conveyor belt 500 reaches the other end of the first conveyor belt 500 through each manufacturing process as the first conveyor belt 500 moves, and passes through the manufacturing processes. The manufacture of the reflective polarizer 338 according to the invention is complete. The reflective polarizer 338, thus manufactured, is rolled and stored in the upper portion of the other end of the first conveyor belt 500.

Hereinafter, each manufacturing apparatus and manufacturing process shown schematically in FIG. 4 are explained in full detail.

The base film 400 introduced into the first conveyor belt 500 first moves to the UV resin coating device 510.

Referring to FIG. 5, the UV resin applicator 510 includes a UV resin supply part 512 and a knife 514. The UV resin supply unit 512 supplies the resin of a certain amount of UV to the base film 400 at a constant speed. The UV resin supplied to the base film 400 is located on one side of the UV resin supply part 512 as the base film 400 moves on the first conveyor belt 500, and is spaced apart from the base film 400 by a predetermined distance. The UV resin layer 412 having a constant thickness is coated on the base film 400 while passing through the knife 514.

The base film 400 coated with the UV resin layer 412 moves to the UV resin curing apparatus 520 along the first conveyor belt 500.

Referring to FIG. 6A, the UV resin curing apparatus 520 includes a second conveyor belt 522, an ultraviolet lamp 526, a plurality of lenses 524, and an optical film 528.

The second conveyor belt 522 is controlled to move at the same speed as the first conveyor belt 500.

At least one ultraviolet lamp 526 is installed, and is a device for providing ultraviolet (UV) to the UV resin layer 412.

UV generated by the ultraviolet lamp 526 is focused in a direction perpendicular to the lenses 524 as it passes through the optical film 528. On the other hand, the optical film 528 can be selectively used according to the design conditions of the UV resin curing device 520.

UV light passing through the optical film 528 is incident in a direction perpendicular to the lenses 524. The lenses 524 preferably use a lenticular lens.

UV incident on the lenses 524 has a constant focal length as shown in FIG. 6B and is emitted to irradiate a specific area of the UV resin layer 412. At this time, since the base film 400 is a transparent material, all of the UV can be irradiated to the UV resin layer 412.

The UV emitted from the lenses 524 is irradiated to a specific region 414 of the UV resin layer 412 and positioned at the second conveyor 522 at the same speed as that of the first conveyor belt 500. As 524 moves, the UV emitted from lenses 524 can continue to be irradiated to a specific area 414 of the UV resin layer 412.

Accordingly, as shown in FIG. 6C, the specific region 414 of the UV resin layer 412 cures in response to UV. That is, the UV resin layer 412 of the region 416 not irradiated with UV is not cured, and the UV resin layer 412 of the specific region 414 irradiated with UV is cured.

As such, the base film 400 coated with the UV resin layer 412 on which the specific region 414 irradiated with UV is moved is moved to the cleaning apparatus. The UV resin layer 412 is washed with a cleaning liquid capable of washing the UV resin, such as an organic solvent, in the washing apparatus. Accordingly, the UV resin of the uncured portion 416 of the UV resin layer 412 in the UV curing apparatus is removed.

Subsequently, when moving to a drying apparatus to dry the base film 400 coated with the UV resin layer 412, the reflective polarizer 338 in which constant lines 410 are patterned with UV resin as shown in FIG. 7. ) Is formed.

That is, the UV resin is patterned into a plurality of lines 410 having regular intervals. At this time, the interval between the UV resins is about 200 nm or less. Preferably between about 100 nm and 130 nm.

The spacing between the lines 410 may be controlled by adjusting the characteristics of the lenses 524 that irradiate the UV resin layer 412 with UV.

Preferred embodiments of the invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention will be capable of various modifications, changes, additions within the spirit and scope of the present invention, such modifications, changes And additions should be considered to be within the scope of the following claims.

As described above, the manufacturing device and method of the polarizer used in the backlight device according to the present invention forms a line at a predetermined interval by passing ultraviolet rays through the lens to irradiate the UV resin to perform the role of a thin film multilayer reflective polarizing film There is an advantage that can be produced a reflective polarizer.

In addition, the manufacturing apparatus and method of the polarizer used in the backlight device according to the present invention has the advantage that it is possible to mass-produce, shorten the manufacturing time.

Claims (13)

(a) applying UV Resin onto a base film moving on a conveyor belt; And (b) irradiating the UV resin-coated base film through a lens having a specific focal length to form a plurality of lines having a predetermined interval, wherein the polarizer is used in a backlight device. Manufacturing method. The method of claim 1, In the step (a), the UV resin manufacturing method of the polarizer characterized in that it contains a metal material. The method of claim 1, In the step (b), the lens is a lenticular lens (Lenticular lens) characterized in that the manufacturing method of the polarizer. The method of claim 1, In the step (b), the interval between the lines, the manufacturing method of the polarizer, characterized in that 100nm to 130nm. The method of claim 1, In step (b), (c) irradiating ultraviolet light through the lens on the bottom surface of the base film to a UV resin in a portion where the line is formed; And (d) irradiating the ultraviolet rays to the portion where the line is to be formed by moving the lens at the same speed as the movement speed of the base film on the conveyor belt, and curing the UV resin of the portion where the line is to be formed. Method for producing a polarizer, characterized in that. The method of claim 5, In step (b), (e) washing the base film to remove uncured portions of the UV resin applied to the base film; And (f) drying the base film including a plurality of lines formed by curing the UV resin. A first conveyor belt for moving the base film; UV resin coating device for applying a UV resin to a predetermined thickness on the base film moving on the first conveyor belt; And And a UV resin curing device that irradiates ultraviolet rays through a lens having a specific focal length to the base film to which the UV resin is applied, thereby curing the UV resin to form a line having a predetermined interval. Apparatus for producing a polarizer used. The method of claim 7, wherein The UV resin curing device, At least one ultraviolet lamp; The plurality of lenses converting the ultraviolet rays generated by the ultraviolet lamp into ultraviolet rays having a specific focal length and irradiating the base film; And And a second conveyor belt for moving the lenses to correspond to the moving speed of the first conveyor belt. The method of claim 8, And an optical film for condensing the ultraviolet rays generated by the ultraviolet lamp and providing the lenses to the lenses. The method of claim 7, wherein The UV resin manufacturing apparatus of the polarizer characterized in that it contains a metal material. The method of claim 7, wherein The lens is a lenticular lens (Lenticular lens) characterized in that the manufacturing device of the polarizer. The method of claim 7, wherein The interval between the lines, the manufacturing apparatus of the polarizer, characterized in that 100nm to 130nm. The method of claim 7, wherein A washing apparatus for removing an uncured portion of the UV resin applied to the base film; And And a drying device for drying the base film including a plurality of lines formed by curing the UV resin.

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