KR20170125212A - Laser cutting apparatus and method - Google Patents

Abstract

The present invention relates to a laser cutting apparatus to laser cut a polarizing film formed of a plurality of film layers including at least a protective film layer, an active layer, and a transmittance enhancement layer, comprising: a laser oscillator oscillating a laser beam; and a laser head repeatedly irradiating the polarizing film with the laser beam along a predetermined intended cutting line, and cutting the polarizing film in a stepwise manner by a cutting depth of a predetermined range. According to the laser cutting apparatus and a method thereof, the polarizing film is cut in the stepwise manner by a cutting depth of a predetermined range, and a cooling time to sufficiently cool a cut surface of the polarizing film is provided between cutting steps such that an empty space, wherein bubbles may be trapped, is able to be prevented from being formed on the cut surface of the polarizing film due to the overheated and expanded cut surface of the polarizing film. As such, in accordance with the laser cutting apparatus and the method thereof, bubbles are prevented from being trapped on the cut surface of the polarizing film such that detachment in an attachment area of the polarizing film and a liquid crystal panel is able to be prevented from occurring due to the bubbles trapped on the cut surface of the polarizing film.

Description

[0001] The present invention relates to a laser cutting apparatus and method,

The present invention relates to an apparatus and a method for cutting a polarizing film.

A cathode ray tube (CRT), which is one of the display devices conventionally used, has been mainly used for monitors such as a TV, a measurement device, and an information terminal device. However, due to the large weight and size of the CRT itself, Could not respond positively to the demand of

In order to replace such a CRT, a liquid crystal display device having advantages of small size and light weight has been actively developed, and in recent years, a demand for a flat panel display device has been developed to such a degree that it can sufficiently perform its function.

The principle of image realization of such a liquid crystal display device utilizes optical anisotropy and polarization property of a liquid crystal. The liquid crystal has an anisotropy having a long molecular structure and a directionality in arrangement, and a polarization in which the direction of the molecular arrangement is changed according to the size It has properties. Accordingly, the liquid crystal display device has a liquid crystal panel composed of a pair of transparent insulating substrates, each of which has electric field generating electrodes formed on the surfaces thereof facing each other with a liquid crystal layer sandwiched therebetween as an essential component, The arrangement direction of the molecules is artificially adjusted, and various images are displayed by using the transmittance of light which is changed at this time.

At this time, a polarizing film for visualizing the liquid crystal alignment change of the liquid crystal display device is positioned on the upper and lower sides of the liquid crystal panel. Since the polarizing film transmits light of the polarized light component coinciding with the transmissive side, The degree of light transmission is determined by the arrangement of the axes and the arrangement characteristics of the liquid crystals.

Such a polarizing film is produced by cutting a polarizing film by using a wood cutting device or a laser cutting device, and the proportion of use of the laser processing device is gradually increasing due to the physical superiority of the laser beam. However, in the conventional laser cutting apparatus, air bubbles are generated on the cut surfaces of the polarizing film due to defective cutting quality of the polarizing film, and there is a problem that lifting phenomenon occurs at the attachment region of the polarizing film and the liquid crystal panel.

It is an object of the present invention to provide a laser cutting apparatus and a laser cutting method in which a structure is improved so that bubbles are not generated on a cut surface of a polarizing film.

According to an aspect of the present invention, there is provided a laser cutting apparatus for cutting a polarizing film composed of a plurality of film layers including at least a protective film layer, an active layer, and a transmittance improving layer, A laser oscillator for oscillating a laser beam; And a laser head repeatedly irradiating the laser beam along a predetermined line to be cut on the polarizing film to cut the polarizing film stepwise by a predetermined cut depth.

Preferably, the laser head is a laser scanner capable of irradiating the laser beam in a predetermined scanning area.

Preferably, the laser head has at least one galvanometer mirror capable of adjusting an optical path of the laser beam.

Preferably, the apparatus further includes a transfer unit capable of transferring the laser head or the polarizing film in parallel with the line to be cut.

Preferably, the transfer unit continuously transfers the laser head or the polarizing film at a predetermined transfer speed, and the laser head moves the laser beam along a predetermined section of the line to be cut belonging to the scan area at a predetermined scan speed .

Preferably, the scan speed is set to be faster than the feed speed.

Preferably, the transfer unit intermittently transfers the laser head or the polarizing film by a predetermined unit distance so as to repeat the transfer or stop of the polarizing film, and the laser head moves the laser head or the polarizing film to the transfer stop The laser beam is repeatedly irradiated repeatedly at a predetermined scan speed along a specific section of the line to be cut belonging to the scan area.

Preferably, the unit distance is set to be equal to or shorter than the length of the specific section.

Preferably, the laser head repeatedly irradiates the laser beam along a predetermined line to be cut along a predetermined direction.

Preferably, the transfer unit continuously conveys the laser head or the polarizing film at a predetermined speed, and the laser head irradiates the laser beam repeatedly in the one direction along a specific section of the line to be cut belonging to the scan area .

Preferably, the laser head irradiates the laser beam along the line along which the object is to be cut so as to form an acute angle or an obtuse angle with the polarizing film with respect to the extending direction of the line along which the object is intended to be cut.

Preferably, the laser beam has a wavelength of 9.3 탆 to 10.6 탆.

Preferably, the laser beam is a CO ₂ laser beam.

Preferably, the protective film layer comprises at least one of polyethylene terephthalate and polyethylene.

Preferably, the active layer comprises at least one of polyvinyl alcohol and liquid crystal.

Preferably, the transmittance improving layer comprises at least one of acrylic, triacetylcellulose and an olefin polymer.

According to another aspect of the present invention, there is provided a laser cutting method for laser cutting a polarizing film comprising a plurality of film layers including at least a protective film layer, an active layer, and a transmittance improving layer, Wherein the polarizing film is repeatedly irradiated with the laser beam along a predetermined line to be cut on the polarizing film by using a laser head capable of irradiating a laser beam to a predetermined scan region, Stepwise cut.

Preferably, the laser head is continuously conveyed in parallel with the line along which the object is intended to be cut at a predetermined conveying speed, and the laser beam is repeatedly reciprocated at a predetermined scanning speed along a specific section of the line along which the object is intended to be cut, do.

Preferably, the scan speed is set to be faster than the feed speed.

Preferably, the laser head is intermittently conveyed by a predetermined unit distance so as to repeat the feeding or stopping of feeding, and when the feeding is stopped, the laser beam is scanned along a predetermined section of the to-be- Repeatedly scan at the speed.

Preferably, the unit distance is set to be equal to or shorter than the length of the specific section.

Preferably, the laser head is continuously transported in parallel with the line to be cut at a predetermined transporting speed, and at the same time, the laser beam is repeatedly irradiated in a predetermined direction along a specific section of the line to be cut belonging to the scan area .

The apparatus and method for laser cutting according to the present invention are characterized in that the polarizing film is stepwise cut by a predetermined cutting depth to provide a cooling time between the cutting steps so that the cut surface of the polarizing film can be sufficiently cooled, It is possible to prevent an empty space in which the cut surface is overheated and expanded and the bubbles can be trapped on the cut surface of the polarizing film. Therefore, the apparatus and method for cutting a laser according to the present invention prevent the bubbles from being caught on the cut surface of the polarizing film, and cause lifting of the polarizing film and the attachment portion of the liquid crystal panel due to bubbles trapped on the cut surface of the polarizing film Can be prevented.

1 is a sectional view of a polarizing film for cutting using a laser cutting apparatus according to a first embodiment of the present invention;
2 is a perspective view of a laser cutting apparatus according to a first embodiment of the present invention;
3 is a perspective view showing a galvanometer mirror of the laser head shown in Fig. 2;
4 is a view for explaining a laser cutting method of a polarizing film using a laser cutting apparatus according to a comparative example;
Fig. 5 is a sectional view of a polarizing film cut by the laser cutting apparatus shown in Fig. 4; Fig.
6 is a plan view of a polarizing film cut by the laser cutting apparatus shown in Fig.
7 is a view for explaining a laser cutting method using the laser cutting apparatus according to the first embodiment of the present invention.
8 is a cross-sectional view of a polarizing film cut by the laser cutting apparatus shown in Fig.
Fig. 9 is a plan view of a polarizing film cut by the laser cutting apparatus shown in Fig. 7; Fig.
10 is a view for explaining a laser cutting method using a laser cutting apparatus according to a second embodiment of the present invention.
11 is a view for explaining a laser cutting method using a laser cutting apparatus according to a third embodiment of the present invention.
12 is a view for explaining a laser cutting method using a laser cutting apparatus according to a fourth embodiment of the present invention.
13 is a sectional view of a polarizing film cut by the laser cutting apparatus shown in Fig.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

In the drawings, the size of each element or a specific part constituting the element is exaggerated, omitted or schematically shown for convenience and clarity of description. Therefore, the size of each component does not entirely reflect the actual size. In the following description, it is to be understood that the detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a cross-sectional view of a polarizing film for cutting using a laser cutting apparatus according to a first embodiment of the present invention.

A laser cutting apparatus (1) according to a first embodiment of the present invention relates to a laser cutting apparatus for laser cutting a polarizing film (10) composed of a plurality of film layers. The laminated structure of the polarizing film 10 is not particularly limited. For example, as shown in Fig. 1, the polarizing film 10 may include at least a protective film layer 11, an active layer 12, and a transmittance improving layer 13.

First, the protective film layer 11 is a film layer for preventing surface damage of the polarizing film 10.

The material of the protective film layer 11 is not particularly limited. For example, the protective film layer 11 may comprise at least one of polyethylene terephthalate (PET) and polyethylene (PE). 1, the protective film layer 11 is adhered to the first adhesive layer 14 formed by applying a first tackifier to the TAC film layer 15 of the permeation enhancing layer 13 to be described later . The first pressure sensitive adhesive is preferably a pressure sensitive adhesive (PSA), but is not limited thereto.

Next, the active layer 12 is a film layer for changing the polarization characteristics of light.

The active layer 12 may be composed of polyvinyl alcohol (PVA) or a liquid crystal.

Next, the transmittance improving layer 13 is a film layer for transmitting the light source to the front side of the display as much as possible.

The transmittance improving layer 13 may include at least one of triacetyl cellulose (TAC), acrylic, and olefin polymer. In particular, the olefin polymer is preferably a cycloolefin polymer (COP). For example, the transmittance improving layer 12 may be formed of a material having a high transmittance. A TAC film layer 15 provided between the active layer 12 and the protective film layer 11 and a COP film layer 16 provided between the active layer 12 and a release film layer 18 to be described later can do.

This polarizing film 10 may further include a release film layer 18 for separating the adhesive layer for adhering the polarizing film 10 to the liquid crystal panel from contaminants.

The material of the release film layer 18 is not particularly limited. For example, the release film layer 18 may comprise at least one of polyethylene terephthalate (PET) and polyethylene (PE). 1, the release film layer 18 may be adhered to the COP film layer 16 so as to be peeled off from the second adhesive layer 17 formed by applying the second adhesive. Therefore, when attaching the polarizing film 10 to the liquid crystal panel, the release film layer 18 is peeled from the second adhesive layer 17 so that the second adhesive layer 17 is exposed to the outside, The polarizing film 10 can be attached to the liquid crystal film by using the liquid crystal layer 17. The second pressure sensitive adhesive is preferably a pressure sensitive adhesive (PSA), but is not limited thereto.

2 is a perspective view of a laser cutting apparatus according to a first embodiment of the present invention.

Referring to FIG. 2, a laser cutting apparatus 1 according to a first embodiment of the present invention includes a laser oscillator 20 for oscillating a laser beam LV; A laser head 30 for repeatedly reciprocatingly irradiating the polarizing film 10 with the laser beam LV along a predetermined line to be cut E and cutting the polarizing film 10 stepwise by a predetermined cutting depth, ); And a transfer unit (40) capable of transferring the laser head (30) in parallel with the line to be sectioned (E).

First, the laser oscillator 20 is a device for providing a laser beam LV for laser cutting the polarizing film 10.

The laser oscillator 20 is provided on one side of the base A and generates and oscillates a laser beam LV for laser cutting the polarizing film 10. Generally, the laser beam can be cut depending on the wavelength. This is because the laser absorbance for a specific wavelength is changed depending on the material. Further, the wavelength of the laser beam is determined according to the laser source. Therefore, the laser oscillator 20 can oscillate by generating a laser beam LV having a wavelength of 9.3 탆 to 10.6 탆 in consideration of the material of the polarizing film 10 described above. This laser beam LV may be a CO ₂ laser beam.

1, the laser beam LV emitted from the laser oscillator 20 is guided by at least one reflector 20a provided between the laser oscillator 20 and the laser head 30, And can be transmitted to the laser head 30.

FIG. 3 is a perspective view showing a galvanometer mirror of the laser head shown in FIG. 2. FIG.

Next, the laser head 30 is a device for irradiating the polarizing film 10 with the laser beam LV provided from the laser oscillator 20. [

2, the laser head 30 is fixed to a slider 45 of a transfer unit 40 to be described later so as to be transported in parallel with a line E to be cut of the polarizing film 10, And irradiates the laser beam LV transmitted through the laser beam 20a along the line E to be cut of the polarizing film 10. The line to be sectioned E refers to a virtual line set on the polarizing film 10 for cutting the polarizing film 10 to a size corresponding to the liquid crystal panel. For convenience of explanation, the first embodiment of the present invention will be described by taking, as an example, a case where the line along which the object is to be cut E is provided parallel to the width direction of the polarizing film 10 .

The laser head 30 is preferably a laser scanner having at least one galvano mirror capable of adjusting the optical path of the laser beam LV to irradiate the laser beam LV to a predetermined scan area . 3, the laser head 30 is driven by the X-axis servo motor 33 and changes the optical path of the laser beam LV in the width direction of the polarizing film 10 A Y-axis servo motor 37 driven by the Y-axis servo motor and capable of changing the optical path of the laser beam LV in the longitudinal direction of the polarizing film 10 . The laser beam LV whose optical path has been changed by the mirrors 31 and 35 can be condensed by the lens 39 provided in the laser head 30 and irradiated to the polarizing film 10. The lens 39 preferably has an F-theta (f-theta) but is not limited thereto.

Next, the transfer unit 40 is a device for transferring the laser head 30 reciprocally.

The structure of the transfer unit 40 is not particularly limited. For example, as shown in Fig. 2, the transfer unit 40 includes a frame 41 provided so as to cross the polarizing film 10 in the width direction, a frame 41 for guiding the movement of the laser head 30, A slider 45 which is movably provided on the cross rail 43 and is engaged with the laser head 30 and a slider 45 which is provided on the cross rail 43, And a slider moving means 47 for providing a driving force so as to move along the slider.

The frame 41 is provided on the base A so as to cross the polarizing film 10 in the width direction as shown in Fig. 2 and has a plate phenomenon that the polarizing film 10 can pass downward .

The cross rail 43 is provided on the frame 41 so as to be parallel to the width direction of the polarizing film 10, as shown in Fig. The cross rail 43 may have a slit 43a formed parallel to the width direction of the polarizing film 10.

2, the slider 45 is provided inside the cross rail 43 so as to be movable in the width direction of the polarizing film 10 and is coupled with the laser head 30 through the slit 43a. do.

The slider moving means 47 includes a lead screw 47a provided inside the cross rail 43 in parallel with the width direction of the polarizing film 10 and engaged with the slider 45, And a driving motor 47b for driving the lead screw 47a to rotate. The lead screw 47a is driven in the forward or reverse direction by the drive motor 47b to move the laser head 30 coupled to the slider 45 and the slider 45 in the width direction of the polarizing film 10 Can be transported round-trip. The laser beam head 30 coupled to the slider 45 and the slider 45 is cut by the lead screw 47a so as to be cut by the lead screw 47a, And can be reciprocated in parallel with the line E.

On the other hand, the transfer unit 40 has been described as transferring the laser head 30 in parallel to the line along which the object is to be cut E. However, the present invention is not limited thereto. In other words, the transfer unit 40 may be provided with a plurality of drive rolls and driven rolls so as to be capable of transferring the polarizing film 10 in parallel with the line along which the object is intended to be cut E. For convenience of explanation, the first embodiment of the present invention will be described based on the case where the transfer unit 40 transfers the laser head 30 in parallel with the line along which the object is intended to be cut E. [

4 is a view for explaining a laser cutting method using a laser cutting apparatus according to a comparative example.

The laser cutting apparatus 100 according to the comparative example corresponds to a conventional laser cutting apparatus and is configured such that the laser beam LV is irradiated once along the line E to be cut of the polarizing film 10 composed of a plurality of film layers And the polarizing film 10 is cut. 4, the conveying unit (not shown) continuously conveys the laser head 130 at a predetermined conveyance speed in parallel with the line E to be cut of the polarizing film 10, The laser head 130 irradiates a laser beam LV provided from a laser oscillator (not shown) to a point on the line E to be cut facing the laser head 130. 4, the laser beam LV provided from the laser oscillator (not shown) is irradiated once at the conveying speed along the line E to be cut of the polarizing film 10. Then, since the polarizing film 10 is cut at the feeding speed, the cutting speed of the polarizing film 10 is equal to the feeding speed.

Since the film layers of the polarizing film 10 have different materials from each other, the laser absorption rates are also different from each other. Therefore, laser cutting of a film layer having a low laser absorption rate like the COP film layer 16 requires a relatively large energy and cutting time as compared with laser cutting of a film layer having a high laser absorption rate. Therefore, the laser cutting apparatus 100 according to the comparative example smoothly transfers the energy of the laser beam LV to the film layer having a low laser absorption rate, and cuts the polarizing film 10 only by irradiating the laser beam LV once The physical properties of the laser beam LV and the feed rate (= cutting speed) of the laser head 130 are adjusted. For example, the laser beam LV is a CO ₂ laser beam having a frequency of 10 kHz, a pulse width of 4.2 μs, an output of 19.4 W, and a wavelength of 9.4 μm, and the feed rate of the laser head 130 Lt; / RTI >

5 and 6 are diagrams for explaining the case where the physical properties of the laser beam LV and the feed rate (= cutting speed) of the laser head 130 are set as described above, Sectional view and plan view of the film (10). For reference, the adhesive member C shown in Fig. 5 is a member that is attached to such two pieces and interconnects the two pieces after the polarizing film 10 is laser cut and separated into two pieces. Such an adhesive member (C) assists in easily collecting the two pieces at a time, but is not related to laser cutting of the polarizing film (10).

The laser cutting apparatus 100 according to the above-described comparative example is configured such that during the laser cutting of the film layer having a low laser absorption rate, such as the COP film layer 16, The energy of the laser beam LV is continuously applied. Then, the cut surface of the film layer in which the laser cutting is completed first becomes an overheated state by the energy of the laser beam LV continuously applied even after completion of the laser cutting. That is, the cut surface of the film layer in which the laser cutting is completed first is continuously heated until the laser cutting of the film layer having a low laser absorption rate is completed, while not being sufficiently cooled even after completion of the laser cutting. Therefore, as shown in Fig. 5, the cut surface of the film layer having a relatively high laser absorption rate among the film layers of the polarizing film 10 is expanded due to the above-mentioned overheating condition. Further, as shown in FIG. 6, a void space is generated in the process of overheat expansion of the cut surface of the overheated expanded film layer, and the bubble B is captured in the void space. Therefore, in the laser cutting apparatus 100 according to the comparative example, since the angle of incidence of the cut surface T of the polarizing film 10 is large and the polarizing film 10 is polarized by the bubble B captured on the cut surface T of the polarizing film 10, A floating phenomenon occurs at the attachment portion of the film 10 and the liquid crystal panel.

7 is a view for explaining a laser cutting method using the laser cutting apparatus according to the first embodiment of the present invention.

The laser cutting apparatus 1 according to the first embodiment of the present invention repeatedly reciprocates the laser beam LV along the line E to be cut of the polarizing film 10 so that the polarizing film 10 is irradiated repeatedly Cut stepwise by the cutting depth of the range. That is, the laser cutting apparatus 1 according to the first embodiment of the present invention cuts the polarizing film 10 in a stepwise manner by reciprocally irradiating the laser beam LV to the line to be cut E several times . 7, the transfer unit 40 continuously transfers the laser head 30 at a predetermined conveying speed, and the laser head 30 irradiates the laser beam LV to the above-mentioned scan area < RTI ID = 0.0 > At a predetermined scan speed along a specific section S of the line along which the object is intended to be cut E belonging to. The scan speed is set such that the laser beam LV can be alternately repeatedly irradiated along the line along which the laser beam 30 is intended to be cut or along the line E to be cut, Is set to be faster than the conveyance speed. The laser beam LV is moved along the line E to be cut along the feed direction of the laser head 30 in the same direction as the scanning direction of the laser head 30, Speed - It is irradiated at a speed corresponding to the above feed rate. When the scanning direction of the laser head 30 is opposite to the feeding direction of the laser head 30, the laser beam LV is moved in the opposite direction of the feeding direction of the laser head 30 along the line along which the laser beam 30 is intended to be cut At a speed corresponding to the scan speed + the feed speed. Then, the polarizing film 10 is cut at a speed corresponding to the scanning speed + the feeding speed in accordance with the scanning direction of the laser beam LV, so that the cutting speed of the polarizing film 10 is the scanning speed +/- the feeding speed .

The laser cutting apparatus 1 according to the first embodiment of the present invention repeatedly reciprocates the laser beam LV along the line along which the substrate is to be cut E and cuts the laser beam LV stepwise by a predetermined cutting depth The physical properties of the laser beam LV and the cutting speed of the polarizing film 10 are adjusted. For reference, the cutting depth of the polarizing film 10 can be changed within a predetermined range according to the material of the film layer where laser cutting is currently being performed. In consideration of these points, the pulse width and the output of the laser beam LV are set to be relatively low as compared with the laser cutting apparatus 100 according to the comparative example described above, and the cutting speed of the polarizing film 10 is set to be lower than that of the comparative example Is set relatively faster than the laser cutting apparatus 100 according to the first embodiment. For example, the laser beam LV is a CO ₂ laser beam having a frequency of 10 kHz, a pulse width of 3.0 μs, an output of 2.5 W and a wavelength of 9.4 μm, a feed rate of the laser head 30 is 0.2 μV, 30) is 1 스캔, and the cutting speed of the polarizing film 10 may be 1 賊 0.2 ㎧.

8 and 9 are diagrams showing a case where the physical properties of the laser beam LV, the feed speed of the laser head 30, the scan speed of the laser head 30 and the cutting speed of the polarizing film 10 are set as described above. Sectional view and a plan view of a polarizing film 10 cut by a laser cutting apparatus according to a first embodiment of the present invention.

The laser cutting apparatus 1 according to the first embodiment of the present invention described above sets the pulse width and the output of the laser beam LV lower than that of the laser cutting apparatus 100 according to the comparative example, Is set faster than the laser cutting apparatus 100 according to the comparative example and the laser beam LV is repeatedly irradiated repeatedly along the line along which the cut is to be cut E. [ As a result, the laser beam LV is repetitively and repeatedly irradiated to the polarizing film 10 in a state where the energy level is lower than that of the laser cutting apparatus 100 according to the comparative example described above, ) Is cut stepwise by a predetermined cutting depth. Then, a predetermined cooling time in which the cut surface of the film layer that has already been cut is sufficiently cooled can be provided between the cut steps, so that the cut surface of the film layer is prevented from overheating. 8, the cut surface T of the polarizing film 10 is flattened relative to the laser cutting apparatus 100 according to the comparative example described above, so that a void space in which the bubble B can be captured Is prevented from being formed on the cut surface (T) of the polarizing film (10). In addition, the inclination angle of the cut surface T of the polarizing film 10 is smaller than that of the laser cutting apparatus 100 according to the comparative example described above. The laser cutting apparatus 1 according to the first embodiment of the present invention prevents the bubble B from being caught on the cut surface T of the polarizing film 10, And it is possible to prevent a floating phenomenon from occurring in the attachment region of the liquid crystal panel.

10 is a view for explaining a laser cutting method using the laser cutting apparatus according to the second embodiment of the present invention.

The laser cutting apparatus 2 according to the second embodiment of the present invention differs from the laser cutting apparatus 1 according to the first embodiment of the present invention in that the laser irradiation system is different from the laser cutting apparatus 1 according to the above- Is the same as the laser cutting apparatus 1 according to the first embodiment. Therefore, the laser cutting apparatus 2 according to the second embodiment of the present invention will be described below focusing on the laser irradiation system.

The above-described laser cutting apparatus 1 according to the first embodiment of the present invention repeatedly irradiates the polarizing film 10 with the laser beam LV while continuously feeding the laser head 30. On the other hand, the laser cutting apparatus 2 according to the second embodiment of the present invention repeatedly irradiates the polarizing film 10 with the laser beam LV when the feeding of the laser head 30 is stopped. For example, as shown in Fig. 10, the transfer unit 40 intermittently transfers a predetermined unit distance L repeatedly so as to repeatedly transfer or stop the laser head 30, and at the same time, The head 30 repeatedly irradiates the laser beam LV repeatedly at a predetermined scan speed along the specific section S of the line E to be cut of the polarizing film 10 belonging to the scan area when the feed is stopped. Here, it is preferable that the unit distance L is set to be equal to the length of the specific section S or to be shorter than the length of the specific section S. Then, the ends of the specific sections S are tangent to each other or overlap each other by a predetermined length, so that the polarizing film 10 can be cut smoothly over the entire section.

The laser cutting apparatus 2 according to the second embodiment of the present invention repeatedly irradiates the polarizing film 10 with the laser light repeatedly while the feeding of the laser head 30 is stopped, Unlike the laser cutting apparatus 1 according to the first embodiment of the present invention in which the cutting speed of the polarizing film 10 is different according to the scanning direction of the laser beam 30, It is possible to maintain a constant cutting speed.

11 is a view for explaining a laser cutting method using the laser cutting apparatus according to the third embodiment of the present invention.

The laser cutting apparatus 3 according to the third embodiment of the present invention differs from the cutting apparatus 1 according to the first embodiment of the present invention described above in that the laser irradiation decoration is different from that of the above- Is the same as the laser cutting apparatus 1 according to the embodiment. Therefore, in the following, the laser cutting apparatus 3 according to the third embodiment of the present invention will be described focusing on the laser irradiation system.

The laser cutting apparatus 3 according to the third embodiment of the present invention irradiates the laser beam LV repeatedly in a predetermined direction along a line along which the substrate is to be cut E so as to move the polarizing film 10 in a predetermined range By the cutting depth of the cutter. 11, the conveying unit 30 conveys the laser head 20 in a predetermined conveying direction so as to be parallel to the line E to be cut, while at the same time, the laser head 20 And repeatedly irradiates the laser beam LV in a direction opposite to the transport direction along a specific section S belonging to the current scan area. However, the present invention is not limited thereto, and the laser head 20 may repeatedly irradiate the laser beam along the specific section S in the transport direction.

The laser cutting apparatus 1 according to the first embodiment described above repeatedly irradiates the laser beam LV repeatedly along the line along which the substrate is to be cut E so that the polarizing film 10 is staggered by a predetermined cut- . According to the laser cutting apparatus 1 according to the first embodiment described above, a cooling time is provided so that the cut surface T of the polarizing film 10 can be cooled between respective cutting steps. Therefore, the cooling time of the cut surface T is shortened toward the end of the scan region in which the scan direction of the laser beam LV is reversely changed due to the laser beam LV being radially reciprocated along the line along which the object is intended to be cut Loses. Since the laser cutting apparatus 1 according to the third embodiment repeatedly irradiates the laser beam LV only in one direction along the line along which the substrate is intended to be cut E, The cooling time can be uniformly given over the entire area of the scan area.

FIG. 12 is a view for explaining a laser cutting method using a laser cutting apparatus according to a fourth embodiment of the present invention, and FIG. 13 is a sectional view of a polarizing film cut by the laser cutting apparatus shown in FIG.

The laser cutting apparatus 4 according to the fourth embodiment of the present invention differs from the cutting apparatus 1 according to the first embodiment of the present invention described above in that the laser irradiation decoration is different from that of the above- Is the same as the laser cutting apparatus 1 according to the embodiment. Therefore, the laser cutting apparatus 4 according to the fourth embodiment of the present invention will be described below focusing on the laser irradiation system.

The laser cutting apparatus 4 according to the fourth embodiment of the present invention is configured to repeatedly irradiate the laser beam LV repeatedly along a line E to be cut or repeatedly irradiate the laser beam LV in a predetermined direction, Is irradiated along the line E to be cut at an acute angle or an obtuse angle with the polarizing film 10 with reference to the extending direction of the line E to be cut so that the polarizing film 10 is cut by a predetermined cutting depth Stepwise cut.

12, when the line along which the object is intended to be cut E is set to be in parallel with the width direction of the polarizing film 10, the laser head 20 is moved in the width direction of the polarizing film 10 The laser beam LV is irradiated along the line E to be cut at an acute angle or an obtuse angle with the polarizing film 10 and the laser beam LV is irradiated when viewed in the longitudinal direction of the polarizing film 10 Repeatedly reciprocating along the line E or repeatedly irradiating in a predetermined direction. 13, the polarizing film 10 is formed so that the cut surface T is inclined by a predetermined cutting depth so as to form an inclined surface inclined at an angle corresponding to the irradiation angle [theta] of the laser beam LV Respectively. Therefore, the laser cutting apparatus 4 according to the fourth embodiment of the present invention prevents bubbles from being captured on the cut surface T, and prevents gas (fume) generated when the polarizing film 10 is cut It can be guided toward the irradiation direction of the laser beam LV and smoothly removed, and the angle of the cut surface T can be adjusted to the product characteristic.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

1, 2: Laser cutting device
10: polarizing film
11: protective film layer
12: active layer
13: Transmittance improving layer
14: first adhesive layer
15: TAC film layer
16: COP film layer
17: Second adhesive layer
18: release film layer
20: laser oscillator
20a: Reflector
30: Laser head
31: X-axis mirror
33: X axis servo motor
35: Y-axis mirror
37: Y-axis servo motor
39: Lens
40:
41: frame
43: Cross rail
43a: slit
45: Slider
47: Slider moving means
47a: Lead Screw
47b: drive motor

Claims (22)

A laser cutting apparatus for laser cutting a polarizing film composed of a plurality of film layers including at least a protective film layer, an active layer and a transmittance improving layer,
A laser oscillator for oscillating a laser beam; And
And a laser head repeatedly irradiating the laser beam along a predetermined line to be cut on the polarizing film to cut the polarizing film stepwise by a predetermined cutting depth. The method according to claim 1,
The laser head
Wherein the laser beam is a laser scanner capable of irradiating the laser beam in a predetermined scan area. 3. The method of claim 2,
The laser head
And at least one galvanometer mirror capable of adjusting an optical path of the laser beam. 3. The method of claim 2,
Further comprising: a transfer unit capable of transferring the laser head or the polarizing film in parallel with the line to be cut. 5. The method of claim 4,
Wherein the transporting unit continuously transports the laser head or the polarizing film at a predetermined transporting speed,
Wherein the laser head repeatedly irradiates the laser beam repeatedly at a predetermined scan speed along a specific section of the line to be cut belonging to the scan area. 6. The method of claim 5,
Wherein the scan speed is set to be faster than the feed speed. 5. The method of claim 4,
The transfer unit intermittently feeds the laser head or the polarizing film by a predetermined unit distance so as to repeat the transfer or the stop of the transfer,
Wherein the laser head repeatedly reciprocally irradiates the laser beam at a predetermined scan speed along a specific section of the line to be cut belonging to the scan area when the laser head or the polarizing film stops feeding, Device. 8. The method of claim 7,
Wherein the unit distance is set to be equal to or shorter than a length of the specific section. 5. The method of claim 4,
Wherein the laser head repeatedly irradiates the laser beam in a predetermined direction along the line along which the object is intended to be cut. 10. The method of claim 9,
Wherein the transfer unit continuously transfers the laser head or the polarizing film at a predetermined speed,
Wherein the laser beam repeatedly irradiates the laser beam in the one direction along a specific section of the line to be cut belonging to the scan area. The method according to claim 1,
Wherein the laser beam irradiates the laser beam along the line to be cut so as to form an acute angle or an obtuse angle with the polarizing film with respect to the extending direction of the line along which the object is intended to be cut. The method according to claim 1,
Wherein the laser beam has a wavelength of 9.3 탆 to 10.6 탆. 13. The method of claim 12,
Wherein the laser beam is a CO ₂ laser beam. The method according to claim 1,
Wherein the protective film layer comprises at least one of polyethylene terephthalate and polyethylene. The method according to claim 1,
Wherein the active layer comprises at least one of polyvinyl alcohol and liquid crystal. The method according to claim 1,
Wherein the transmittance improving layer comprises at least one of acrylic, triacetylcellulose and an olefin polymer. A laser cutting method for laser cutting a polarizing film composed of a plurality of film layers including at least a protective film layer, an active layer and a transmittance improving layer,
The polarizing film is repeatedly irradiated with the laser beam along a predetermined line to be cut on the polarizing film by using a laser head capable of irradiating a laser beam in a predetermined scan region to cut the polarizing film stepwise by a predetermined cut depth And a laser beam. 18. The method of claim 17,
The laser head is continuously conveyed in parallel with the line along which the object is intended to be cut at a predetermined feeding speed and at the same time repeatedly reciprocatingly irradiates the laser beam at a predetermined scanning speed along a specific section of the line to be cut belonging to the scanning area . 19. The method of claim 18,
Wherein the scan speed is set to be faster than the feed speed. 18. The method of claim 17,
The laser head is intermittently conveyed by a predetermined unit distance so as to repeat the feeding or stopping of feeding, and when the feeding is stopped, the laser beam is repeatedly ejected at a predetermined scanning speed along a specific section of the line to be cut belonging to the scanning area Is irradiated with laser light. 21. The method of claim 20,
Wherein the unit distance is set to be equal to or shorter than a length of the specific section. 18. The method of claim 17,
Wherein the laser head is continuously transported in parallel with the line along which the object is intended to be cut at a predetermined feeding speed and simultaneously irradiates the laser beam repeatedly in a predetermined direction along a specific section of the line to be cut belonging to the scan area Lt; / RTI >

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