WO2012046587A1

WO2012046587A1 - Laser cutter and slitter with same

Info

Publication number: WO2012046587A1
Application number: PCT/JP2011/071924
Authority: WO
Inventors: 幸治植田; 和範岸▲崎▼
Original assignee: 住友化学株式会社
Priority date: 2010-10-06
Filing date: 2011-09-26
Publication date: 2012-04-12
Also published as: JP5800486B2; KR20170045376A; CN103153526B; JP2012076143A; CN103153526A; TW201221262A; KR20130106847A; TWI501829B

Abstract

This laser cutter (10) is a device for cutting a polarizing film (6) by applying a laser beam (L6) thereto. The laser cutter (10) is provided with: a laser beam oscillator (1) for oscillating a laser beam (L1); a bend mirror (3) for reflecting the laser beam, which is oscillated by the laser beam oscillator (1), to the polarizing film (6); and a condenser lens (5) disposed between the polarizing film (6) and the bend mirror (3) and condensing a laser beam (L6). A beam splitter (4) through which the laser beam (L3) is transmitted and by which the laser beam (L3) is reflected is provided between the bend mirror (3) and the condenser lens (5).

Description

Laser cutting apparatus and slitter machine equipped with the same

The present invention relates to a laser cutting device and a slitter machine equipped with the same.

Polarizing films are widely used for liquid crystal panels. Conventionally, in the processing step of a polarizing film, a half cut of a polarizing film that cuts only the polarizing film in a laminate including the polarizing film, or cutting of an end portion of the polarizing film is performed. Although the polarizing film is cut with a blade, foreign matter such as film residue is hardly generated from the object to be cut. When this foreign material is mixed in the polarizing film, the yield is lowered.

Therefore, in recent years, laser cutting has been performed. When cutting with a laser, foreign objects such as film scraps are less likely to be generated from an object to be cut compared to cutting with a blade. This can suppress a decrease in yield. For this reason, the cutting method is useful, and various methods have been developed (for example, Patent Documents 1 and 2).

Japanese Patent Publication “Japanese Patent Laid-Open No. 2008-302376 (Released on Dec. 18, 2008)” Japanese Patent Publication “Japanese Unexamined Patent Application Publication No. 2009-22978 (published on Feb. 5, 2009)”

However, the conventional method for cutting a polarizing film using a laser has a problem that a problem occurs when the relatively moving polarizing film is cut. In other words, when the low output side of the laser is used, there is a problem that the laser output is unstable, so that proper cutting cannot be performed.

Specific explanation will be given below. When cutting the conveyed polarizing film, most of the cutting is performed while conveying the polarizing film at a constant speed. In order to improve production efficiency, the constant speed is a large speed of about 50 m / s, for example. Therefore, the polarizing film is cut even when accelerating and decelerating around a constant speed from the viewpoint of increasing the yield.

In the constant speed stage where the conveyance speed of the polarizing film is large, the energy per unit time of the portion irradiated with the laser decreases. Therefore, it is necessary to increase the laser output necessary for cutting. On the other hand, at the stage where the conveyance speed of the polarizing film is low, the energy per unit time of the portion irradiated with the laser increases. As a result, there is a risk that quality will deteriorate due to excessive heat acting on the cut surface of the polarizing film. Therefore, it is necessary to suppress the output of the laser.

Here, there is a problem that the oscillation of the laser may become unstable when the low output side of the laser is used to suppress the output of the laser. For this reason, the adjusted output is blurred, and there is a possibility that energy sufficient to cut the polarizing film may not be irradiated, and even at a stage where the conveyance speed is low, the quality of the cut surface is not deteriorated with a stable output. There is a demand for a laser cutting device for cutting a polarizing film.

In connection with such a problem, Patent Document 2 discloses a laser processing method in which the relative movement speed between the workpiece and the laser light is increased and the number of times of laser light irradiation is reduced. According to this technique, it is possible to avoid the etching depth from becoming excessively deep due to the increase in the power of the laser beam caused by the unstable output of the laser oscillator. However, in this technique, it is necessary to increase the relative moving speed between the workpiece and the laser beam, and there is a problem that it is difficult to apply when the relative speed is low.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a laser cutting device in which the output of the laser light does not become unstable and the quality of the cut surface of the polarizing film does not deteriorate. It is to provide.

In order to solve the above-described problems, the laser cutting device of the present invention is a laser cutting device that irradiates and cuts a polarizing film by irradiating a laser beam. A bend mirror that reflects the laser light to the polarizing film, and a condensing lens that is disposed between the polarizing film and the bend mirror, and condenses the laser light. A beam splitter for transmitting and reflecting the laser light is provided between them.

In the laser cutting device of the present invention, the laser beam is split into transmitted light and reflected light by the beam splitter, and the polarizing film is cut by the transmitted light. Therefore, even if the output of the laser beam oscillator is large, the energy of the laser beam irradiated on the polarizing film can be reduced. As a result, even when the relative speed between the laser cutting device and the polarizing film is small, the laser light oscillator can be used at a high output. That is, it is possible to obtain output stability, which is an advantage when the high output side of the laser beam oscillator is used. On the other hand, since the energy applied to the polarizing film by the beam splitter is reduced, it is possible to suppress degradation of the quality of the cut surface, which is a problem when the high output side of the laser oscillator is used.

As described above, the laser cutting device of the present invention includes a laser light oscillator that oscillates laser light, a bend mirror that reflects the laser light oscillated from the laser light oscillator to a polarizing film, a polarizing film, and a bend mirror. And a condensing lens for condensing the laser light, and a beam splitter for transmitting and reflecting the laser light between the bend mirror and the condensing lens.

Therefore, even when the relative speed between the laser cutting device and the polarizing film is small, the laser light oscillator can be used at a high output. That is, it is possible to obtain output stability, which is an advantage when the high output side of the laser beam oscillator is used. On the other hand, since the energy applied to the polarizing film by the beam splitter is reduced, it is possible to suppress the deterioration of the quality of the cut surface, which is a problem when the high output side of the laser oscillator is used. Play.

It is sectional drawing which shows the laser cutting device which concerns on this invention. It is a graph which shows the relationship between the time t at the time of conveying a polarizing film, and the output w. It is sectional drawing which shows the slitter machine which concerns on this invention. It is a top view which shows the cutting process of the polarizing film by the slitter machine which concerns on this invention. It is a side view which shows the polarizing film cut | disconnected in Example 1 and Comparative Example 1. FIG.

An embodiment of the present invention will be described with reference to FIGS. 1 to 4 as follows.

[Cutting device]
FIG. 1 is a cross-sectional view showing a laser cutting device 10 according to the present invention. The laser cutting device 10 includes a laser light oscillator 1, a beam expander 2, a bend mirror 3, a beam splitter 4, and a condenser lens 5.

The laser beam oscillator 1 is a member that oscillates laser beam and is not particularly limited. For example, a CO ₂ laser (carbon dioxide laser), UV laser, semiconductor laser, YAG laser, excimer laser, or the like can be used. Among these, a CO ₂ laser having high output and suitable for cutting a polarizing film is preferable.

When the output of the laser beam oscillator 1 is low, the output of the laser beam tends to become unstable. For this reason, it is preferable that an output is a high output. On the other hand, when the output is too high, the quality of the cut surface of the polarizing film is degraded due to excessive thermal expansion or the like.

The specific output of the laser oscillator 1 is desirably adjusted as appropriate according to the thickness of the polarizing film 6, the conveyance speed of the polarizing film 6, and the ratio of transmission and reflection by a beam splitter 4 described later. From these viewpoints, the output of the laser beam oscillator 1 is preferably 30 W or more and 400 W or less. In addition, when the output of the laser beam oscillator 1 is low, the output becomes unstable. Specifically, when the output is less than 30 W, the output tends to be unstable.

The frequency of the laser light to be irradiated is appropriately changed depending on the output of the laser light oscillator 1, the thickness of the polarizing film 6, the transport speed of the polarizing film, etc., but can generally be 5 kHz or more and 100 kHz or less.

The laser cutting device 10 includes a beam expander 2 as a preferred form. The beam expander 2 is a member that spreads laser light into a parallel light beam, and a known beam expander may be used. With the beam expander 2, the diameter of the laser beam L1 can be expanded to about 2 to 10 times, for example, to obtain the laser beam L2. When the polarizing film 6 is irradiated with the laser light L6, the laser light L6 is easily focused by increasing the diameter of the laser light.

The bend mirror 3 is a member that reflects the laser light oscillated from the laser light oscillator 1 to the polarizing film 6. In the laser cutting device 10, one bend mirror 3 is provided, but it is sufficient if the laser beam L2 can be reflected as the laser beam L3 to the polarizing film 6, and a plurality of bend mirrors 3 may be provided.

The output of the laser oscillator in a general laser cutting device will be described with reference to FIG. FIG. 2 is a graph showing the relationship between the time t when the polarizing film is conveyed and the output w of the laser beam oscillator. When cutting while transporting the polarizing film, first, the polarizing film is accelerated (acceleration region), then at a constant speed suitable for cutting (constant speed region), the polarizing film is decelerated (deceleration region), Cutting ends.

Since the speed of the polarizing film is small in the acceleration region and the deceleration region, the energy per unit time to the polarizing film increases under the same irradiation conditions. Therefore, it is necessary to reduce the output of the laser beam oscillator. For this reason, in a part of the acceleration region and the deceleration region, the output of the laser beam oscillator is low, and the output of the laser beam oscillator becomes unstable (unstable region). As a result, uncutting may occur in the acceleration region and the deceleration region due to the unstable output of the laser oscillator. Due to the above limitations, a general laser cutting device cannot increase the output of the laser beam oscillator in the acceleration region and the deceleration region.

On the other hand, in the laser cutting device 10 according to the present invention, a beam splitter 4 is provided between the bend mirror 3 and the condenser lens 5. The beam splitter 4 is a member that transmits and reflects the laser beam L3, and a known beam splitter can be used. The laser beam L3 is branched by the beam splitter 4 into a laser beam L4 that is transmitted light and a laser beam L5 that is reflected light.

The ratio of transmitting and reflecting the laser light from the beam splitter 4 is not particularly limited, but may be appropriately adjusted according to the output of the laser light oscillator 1, the thickness of the polarizing film 6, the conveying speed of the polarizing film 6, and the like. desirable. When the output of the laser beam oscillator is 30 W or more and 400 W or less, the ratio of transmitting and reflecting the laser beam of the beam splitter is preferably 3: 7 to 7: 3. If it is the said setting range, the laser cutting device 10 can be used conveniently for the cutting | disconnection of a polarizing film.

In the laser cutting device 10, the laser beam L3 is branched into transmitted light and reflected light by the beam splitter 4, and the polarizing film 6 is cut by the transmitted light. Therefore, according to the laser cutting device 10, even if the output of the laser beam oscillator 1 is large, the energy of the laser beam L6 irradiated to the polarizing film 6 can be reduced. That is, even in the acceleration region and the deceleration region, the laser beam oscillator 1 can be used at a high output, and the output stability, which is an advantage when the high output side of the laser beam oscillator 1 is used, is improved. Obtainable. On the other hand, since the energy applied to the polarizing film by the beam splitter 4 is reduced, it is possible to suppress degradation of quality at the cut surface, which is a problem when the high output side of the laser light oscillator 1 is used. .

The laser beam L5 is condensed on the polarizing film 6 by the condenser lens 5. The condensing lens 5 is not particularly limited, and a spherical lens, an aspheric lens, or the like may be used. Since the cutting width is determined by the condensing diameter of the laser light L6, when the polarizing film is cut, the condensing diameter of the laser light L6 is preferably 5 μm or more and 500 μm or less, preferably 10 μm or more and 400 μm or less. It is more preferable that

A known polarizing film may be used as the polarizing film 6 to be cut by the laser cutting device 10. As the polarizing film in the present invention, a long polarizing film is usually used, but a short or plate-shaped polarizing film may be used. The long refers to the length of the polarizing film 6 in the cutting direction of 10 m or more, the short refers to 2 m or more and less than 10 m, and the plate shape refers to 10 cm or more and less than 2 m.

Specifically, as the polarizing film 6, a TAC (triacetyl cellulose) film, a COP (cycloolefin polymer) film, or the like is bonded as a protective film on both surfaces of the polarizer film, and is opposite to the laser cutting device 10. The protective film is laminated on the TAC film via an adhesive. Among the polarizing films 6, examples of the polarizer film located in the center include a film in which a polyvinyl alcohol film is dyed with iodine or the like, and a protective film such as TAC is bonded to the stretched film or the like. it can. Further, in place of the polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, an ethylene / vinyl acetate copolymer partially saponified film, a hydrophilic polymer film such as a cellulose film, etc. Polyene-oriented films such as vinyl chloride dehydrochlorinated products can also be used.

The total thickness including the polarizing film 6 and the protective film is not particularly limited, but may be 100 μm or more and 500 μm or less. In addition, the thickness of the polarizer film among the polarizing films 6 is generally 10 μm or more and 50 μm or less. Furthermore, in addition to the above three layers, other layers may be included within the practical range of the polarizing film 6.

As the protective film, a polyester film, a polyethylene terephthalate film, or the like can be used. The thickness and width of the protective film are not particularly limited, but from the viewpoint of being used as a protective film for a polarizing film, for example, a thickness of 5 μm or more and 50 μm or less, a width of 200 mm or more and 1500 mm or less. A protective film can be preferably used.

The cutting of the polarizing film 6 by the laser cutting device 10 is performed while moving the laser cutting device 10 or the polarizing film 6. Thereby, a cut surface can be formed in the polarizing film 6. Specifically, it can cut | disconnect, moving a polarizing film with the slitter machine mentioned later. In addition, when the laser cutting apparatus 10 is fixed and it cut | disconnects in the state in which the polarizing film 6 was conveyed, since stable cutting | disconnection is possible, it is suitable.

The term “cutting” the polarizing film in the present invention means “cutting at least a part of the polarizing film” and includes a process of forming a predetermined depth in the polarizing film. For example, cutting of the end portion of the polarizing film, half cutting, marking processing, etc. are also included in the act of “cutting”.

[Slitter]
Next, the slitter machine 20 which concerns on this invention is demonstrated. FIG. 3 is a sectional view showing a slitter machine 20 according to the present invention. The slitter machine 20 includes a laser cutting device 10, an unwinding unit 11, transport rolls 12, 12a, 12b, 12c, 12d, 12e, and 12f (hereinafter abbreviated as “12 to 12f”), a length measuring device 14, and a winding unit 13a. -It has 13b.

The unwinding unit 11 holds the long polarizing film 6 and unwinds it to the transport roll 12. It does not specifically limit as the unwinding part 11, A well-known unwinding part can be used. In the slitter machine 20, a cylindrical shaft is used as the unwinding unit 11, and a paper tube or a plastic tube around which the polarizing film 6 is wound can be held. Although not shown, a rotating device that rotates the unwinding portion 11 is provided on the side surface of the unwinding portion 11, and the unwinding portion 11 is rotated by the rotating device to unwind the polarizing film 6 in the transport direction. The tension applied to the polarizing film 6 and the conveying speed of the polarizing film can be set by a rotating device. Moreover, the height of the unwinding part 11 and the position in the horizontal direction of the unwinding part 11 can be adjusted suitably.

Although the unwinding part 11 is installed in one place, it may be installed in two places like the winding

parts

13a and 13b. Thereby, before all the polarizing films 6 of one unwinding part 11 are unwound, it can connect with the polarizing film of another unwinding part, and the time which replace | exchanges the original film of a polarizing film can be reduced.

In the slitter machine 20, transport rolls 12 to 12 f are arranged along the transport path of the polarizing film 6. What is necessary is just to change suitably the arrangement | positioning place of each conveyance roll according to the conveyance path | route of the polarizing film 6. FIG. The said conveyance roll is not specifically limited, What is necessary is just to use a well-known member. Further, the diameter and width of the transport roll are not limited. Usually, the width of the transport roll is about 1.5 m to 2.5 m. Moreover, the slitter machine 20 may be provided with a touch roll that presses the polarizing film 6 against the transport roll.

A laser cutting device 10 is provided between the transport roll 12b and the transport roll 12c. Thus, the laser cutting device 10 should just be provided between the unwinding part 11 and the winding part 13a. The structure of the laser cutting device 10 is as described above.

The winding

sections

13a and 13b are members that wind the polarizing film 6 that has been cut. Similar to the unwinding section 11, the side surfaces of the winding

sections

13a and 13b are provided with a rotating device (not shown) for rotating the winding

sections

13a and 13b, and the winding

sections

13a and 13b are rotated by the rotating apparatus. Thus, the polarizing film 6 is wound in the transport direction. The tension applied to the polarizing film 6 and the conveying speed of the polarizing film can be set by a rotating device. Moreover, the height of the winding

parts

13a and 13b and the position in the horizontal direction can be appropriately adjusted.

According to the slitter machine 20, the polarizing film 6 is conveyed by the unwinding part 11 and the winding part 13a. Although the conveyance speed of a polarizing film is not specifically limited, As an example, it can be 1 m / s or more and 100 m / s or less.

FIG. 4 is a plan view showing the cutting process of the polarizing film 6. As shown in FIGS. 4A to 4C, slits S are formed in the polarizing film 6 by the laser cutting device 10 as the polarizing film 6 is conveyed. In FIG. 4, the laser cutting device 10 is installed so as to cut the periphery of the end portion of the polarizing film 6. This is a case where the end of the polarizing film 6 is slit. The installation position of the laser cutting device 10 is not particularly limited as long as the polarizing film 6 can be irradiated with laser light. For example, if the laser cutting device 10 is installed so that the central portion of the polarizing film 6 is irradiated with laser light, the polarizing film 6 can be divided into two.

Since the slitter machine 20 according to the present invention includes the laser cutting device 10, even when the polarizing film 6 is accelerated or decelerated, i.e., when the conveying speed of the polarizing film is low, the laser light oscillator 1 has a high output. Can be used. As a result, it is possible to obtain output stability, which is an advantage when the high output side of the laser beam oscillator 1 is used. On the other hand, since the energy irradiated to the polarizing film by the beam splitter 4 is reduced, the deterioration of the quality at the cut surface of the polarizing film, which is a problem when the high output side of the laser light oscillator 1 is used, is suppressed. Can do.

Further, the present invention includes the following forms.

In the laser cutting device of the present invention, the output of the laser beam oscillator is preferably 30 W or more and 400 W or less, and the ratio of transmitting and reflecting the laser beam of the beam splitter is preferably 3: 7 to 7: 3. .

When the output of the laser beam oscillator is 30 W or more and 400 W or less, if the ratio of transmitting and reflecting the laser beam of the beam splitter is within the above range, it can be suitably used for cutting a polarizing film.

In the laser cutting device of the present invention, the laser beam oscillator is preferably a CO ₂ laser beam oscillator.

The CO ₂ laser light oscillator has a high output and is suitable for cutting a polarizing film.

Moreover, the slitter machine of this invention is equipped with the unwinding part which winds up a polarizing film, and the winding-up part which winds up a polarizing film, The said laser cutting device is provided between the said unwinding part and winding-up part. Is.

Since the slitter machine according to the present invention includes a laser cutting device, the laser light oscillator can be used at a high output even when the conveyance speed of the polarizing film is low. As a result, it is possible to obtain output stability, which is an advantage when the high output side of the laser beam oscillator is used. On the other hand, since the energy applied to the polarizing film by the beam splitter is reduced, it is possible to suppress deterioration in quality at the cut surface of the polarizing film, which is a problem when the high output side of the laser light oscillator is used. .

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

[Example 1]
The polarizing film was cut using the slitter machine 20 shown in FIG. The polarizing film 6 has a PET film (38 μm), an adhesive layer (22 μm: the adhesive layer is peeled off together with the protective film), a TAC film (80 μm), polyvinyl, as a protective film, in the order from the condensing lens 5 of the laser cutting device 10. An alcohol film (30 μm) and a COP (cycloolefin polymer) film (70 μm) are laminated, and the COP film has a configuration in which a PET film (38 μm) is laminated as a separate film via an adhesive layer. .

First, the polarizing film 6 was accelerated to 50 m / s after 5 seconds by the rotating device of the unwinding unit 11 and the winding unit 13a from the state where the polarizing film 6 was stationary. While accelerating to 50 m / s, the polarizing film 6 was cut under the following conditions.

Laser oscillator: CO ₂ laser Output of laser oscillator: 20 W or more, 280 W or less Laser wavelength: 9.4 μm
Laser frequency: 20 kHz
Condensing diameter of L6: 54 μm
Ratio of transmitted light and reflected light: 5: 5
[Comparative Example 1]
The polarizing film 6 was cut using a comparative cutting device in which the beam splitter 4 was removed from the laser cutting device 10 of the slitter machine 20. The configuration of the polarizing film 6 is the same as in Example 1. Similar to Example 1, the polarizing film 6 was accelerated to 50 m / s. The cutting conditions are as follows.

Laser oscillator: CO ₂ laser Output of laser oscillator: 10 W or more, 140 W or less Laser wavelength: 9.4 μm
Laser frequency: 20 kHz
Condensing diameter of L6: 54 μm
5 is a side view showing the polarizing film 6 cut in Example 1 and Comparative Example 1. FIG. 5A is the polarizing film 6 of Example 1, and FIG. 5B is the polarizing film 6 of Comparative Example 1. As can be seen from both results, the polarizing film 6 of Comparative Example 1 is deformed in its cross section due to thermal expansion. It was also observed that the uppermost PET film had lumps due to thermal expansion. On the other hand, unlike the comparative example 1, in the polarizing film 6 of Example 1, the cut surface is not deformed. Further, no lump is formed on the uppermost PET film. According to the slitter machine (laser cutting device) of the present invention, quality deterioration at the cut surface of the polarizing film can be suppressed even at a conveyance speed of 50 m / s, and the superiority of the present invention is apparent. Is shown in

Furthermore, a test was conducted as to whether or not the cut surface of the polarizing film 6 was good. A test method peels a separate film from the cut | polarized-light polarizing film, and affixes a COP film surface on a glass plate through an adhesion layer. If the COP film is deformed, bubbles are mixed between the COP film and the glass plate. When the polarizing film 6 after cutting of Example 1 and Comparative Example 1 was tested, no air bubbles were observed after being attached to the polarizing film 6 of Example 1, but the polarizing film 6 of Comparative Example 1 was observed. In the sample, bubbles were observed after being attached. This is a result resulting from the deformation state of the fourth COP film in the polarizing film 6. This result also confirms the superiority of the present invention.

The laser cutting device according to the present invention can be used for suitably cutting a polarizing film. Therefore, the present invention can be widely used in the field where a polarizing film is used.

DESCRIPTION OF SYMBOLS 1 Laser beam oscillator 2 Beam expander 3 Bend mirror 4 Beam splitter 5 Condensing lens 6 Polarizing film 10 Laser cutting device 11 Unwinding part 12 * 12a * 12b * 12d * 12e * 12f Conveyance roll 13a * 13b Winding part 14 Length meter 20 Slitting machine L1-L6 Laser light S Slit

Claims

In a laser cutting device that cuts a polarizing film by irradiating a laser beam,
A laser beam oscillator that oscillates the laser beam;
A bend mirror that reflects the laser light oscillated from the laser oscillator to the polarizing film;
It is disposed between the polarizing film and the bend mirror, and includes a condensing lens that condenses the laser light,
A laser cutting device comprising a beam splitter that transmits and reflects the laser light between the bend mirror and a condenser lens.
The output of the laser beam oscillator is 30 W or more and 400 W or less,
The laser cutting device according to claim 1, wherein a ratio of transmitting and reflecting the laser beam of the beam splitter is from 3: 7 to 7: 3.
The laser cutting device according to claim 1, wherein the laser beam oscillator is a CO 2 laser beam oscillator.
An unwinding unit for unwinding the polarizing film, and a winding unit for winding the polarizing film;
A slitter machine comprising the laser cutting device according to any one of claims 1 to 3 between the unwinding unit and the winding unit.