JP2007261915A - Method and apparatus for cutting glass by laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cutting glass comprising the step of irradiating a laser beam onto a glass sheet to form a scribe line thereon, wherein the efficiency of a cutting work is improved by enhancing the utilization rate of the laser beam. <P>SOLUTION: A glass sheet 9 is mounted on the light-reflecting treated surface 2 of a reflecting mirror plate 3, and a laser beam 10 is irradiated onto the surface of the glass sheet 9 through a first focusing lens 6 comprising biconvex lens and a second focussing lens 7 comprising a plano-concave lens. The second focusing lens 3 has a concave reflecting surface 13, so that the laser beam 10 repeatedly condenses on the position about 1/2 of the thickness of the glass sheet 9 as the result of repeated reflection within a resonator structure constituted between the light-reflecting treated surface 2 of the reflecting mirror plate 3 and the concave reflecting surface 13 of the second focussing lens 7, which results in efficient concentration of thermal stress on the area on which the laser condenses. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass cutting method and a cutting apparatus using a laser, and more particularly to a glass cutting method and a cutting apparatus having a laser beam irradiation step.

  Conventionally, a cutting method having a laser beam irradiation process has been proposed as one of means for cutting a glass plate. For example, as shown in FIG. 5, in order to propagate the cutting crack along the set scanning process of the laser beam, inward from the crack start point 51 at the end of the glass plate 50 before the laser beam irradiation. Make an incision with a depth of about 8 mm and a depth of about 0.1 mm.

  Then, the crack starting point 51 at the end of the glass plate 50 is used as the laser beam 52 irradiation starting point, and the laser beam 52 that has started irradiation is scanned along the cutting process set through the incision, and finally Laser beam 52 irradiation that cuts the glass plate 50 vertically is performed. At this time, a water jet 53 is blown in the vicinity of the irradiation region of the laser beam 52, and the laser beam 52 scan is advanced while cooling the portion heated by the laser beam 52 irradiation.

  At this time, when the laser beam 52 is irradiated to the incision region, an expansion stress is generated by the irradiation heat of the laser beam 52, and immediately after that, a tensile compressive stress is generated by cooling by spraying the water jet 53. Thus, since compressive stress is generated in the vicinity of the region where the expansion stress is generated, a stress gradient based on each stress is generated between both regions, and the crack is deeper in the thickness direction of the glass plate 50 than the cut line. 54 will be generated.

Then, the heating by the laser beam 52 irradiation and the cooling by spraying the water jet 53 proceed along the cutting process, whereby a continuous crack 54 is formed along the cutting process. Thereafter, pressure is applied manually or automatically to apply a bending moment to the crack 54 portion from the surface opposite to the laser beam 52 irradiation surface of the glass plate 50, and the glass plate 50 is divided along the cutting process. (For example, refer to Patent Document 1 or 2.)
JP-A-9-150286 Japanese Patent Laid-Open No. 9-012327

  By the way, the conventional method for cutting a glass plate by laser beam irradiation uses a laser beam because the laser beam once transmitted through the glass plate is emitted into the atmosphere as it is and does not contribute to the cutting of the glass plate. The efficiency was not sufficient.

  Therefore, the present invention was devised in view of the above problems, and its object is to cut a glass plate by irradiating it with a laser beam by increasing the utilization efficiency of the laser beam. It is an object of the present invention to provide a method and apparatus for improving work efficiency.

  In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention is a glass cutting method using a laser having a step of forming a scribe line by irradiating a glass plate with a laser beam emitted from a laser oscillator. Then, the laser beam irradiated to the glass plate is caused to generate a thermal stress locally on the glass plate by repeatedly reciprocating the glass plate.

  According to a second aspect of the present invention, in the first aspect of the present invention, the laser beam includes a plane reflecting surface of a reflector plate disposed so as to sandwich the glass plate and a spherical reflecting surface of a lens. It is characterized by reciprocating while repeating reflection in the resonator structure formed between them.

  According to a third aspect of the present invention, in any one of the first or second aspect, the laser oscillator is a YAG laser oscillator that emits a laser beam having a wavelength of 1030 nm or 1064 nm. It is a feature.

  According to a fourth aspect of the present invention, there is provided a glass cutting device using a laser used in a step of forming a scribe line by irradiating a glass plate with a laser beam emitted from a laser oscillator, the glass The plate is sandwiched between the plane reflecting surface of the reflecting plate and the spherical reflecting surface of the lens, and the laser beam applied to the glass plate is formed between the plane reflecting surface of the reflecting plate and the spherical reflecting surface of the lens. The glass plate is repeatedly reciprocated by repeatedly reciprocating within the resonator structure of the ceramic structure, so that a thermal stress is locally generated on the glass plate.

  According to a fifth aspect of the present invention, in the fourth aspect, the laser oscillator is a YAG laser oscillator that emits a laser beam having a wavelength of 1030 nm or 1064 nm.

  According to the laser cutting method and the cutting apparatus of the present invention, the laser beam irradiated to the glass plate in the scribe line forming step is repeatedly concentrated on the glass plate to generate a thermal stress by repeatedly reciprocating the glass plate. I made it.

  Therefore, a method and apparatus for improving the efficiency of the cutting operation by increasing the utilization efficiency of the laser beam has been realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIG. 1 to FIG. 4 (the same parts are given the same reference numerals and the description thereof will be omitted). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

  As shown in FIG. 1, the glass cutting device according to the present invention has a reflecting mirror plate 3 having a light reflecting surface 2 formed on at least one surface on a stage 1 movable in the surface direction. The processing surface 2 is placed so as to be opposite to the stage 1.

  An optical head 4 of a laser oscillator (not shown) is disposed above the reflecting mirror plate 3, and the laser emitting port between the laser emitting port 5 of the optical head 4 and the reflecting mirror plate 3 is the light reflection processing surface 2. A first focus lens 6 and a second focus lens 7 are arranged in order from the side closer to the laser emission port 5 on a straight line connecting the mirror 5 and the reflecting mirror plate 3 to the light reflection processing surface 2.

  That is, the first focus lens 6 and the second focus lens 7 share the optical axis X, and the optical axis X is substantially perpendicular to the light reflection processing surface 2 of the reflector plate 3.

  The first focus lens 6 is a biconvex lens, and the second focus lens 7 is a plano-concave lens. In particular, the second focus lens 7 is coated on both sides, of which a non-reflective coating is applied on the plane side and a total reflection coating is applied on the concave side.

  In addition, an injection nozzle 8 for injecting cooling water or dry air with the injection port directed is provided in the vicinity of the position where the optical axis X of the light reflection processing surface 2 of the reflecting mirror plate 3 penetrates.

  The laser used in the glass cutting apparatus of the present invention adopts a YAG laser having a wavelength of 1030 nm or 1064 nm, which has very high transmission characteristics of glass in consideration of absorption of the laser beam inside the glass.

  Next, a glass cutting method using the laser glass cutting device of the present invention will be described. First, the glass plate 9 to be cut is placed on the light reflection processing surface 2 of the reflecting mirror plate 3 placed on the stage 1.

  And while operating a laser oscillator, the cooling medium, such as cooling water and dry air, is injected from the injection nozzle 8, and the stage 1 on which the reflecting mirror plate 3 on which the glass plate 9 is mounted is placed in a predetermined direction in a predetermined direction. Move at speed.

  Then, a continuous oscillation laser beam 10 is emitted toward the first focus lens 6 from the laser emission port 5 of the optical head 4 of the laser oscillator.

  The laser beam 10 guided to the biconvex lens which is the first focus lens 6 and guided through the first focus lens 6 is directed to the second focus lens 7 while being condensed in the optical axis X direction.

  The laser beam that has reached the plane on which the anti-reflective coating of the plano-concave lens that is the second focus lens 7 is applied is refracted in the direction of the optical axis X and enters the second focus lens 7 to enter the second focus lens 7. The inside is guided to the concave surface on which the total reflection coating is applied.

  The total reflection coating applied to the concave surface of the second focus lens 7 has a property of transmitting the laser beam 10 irradiated from the laser emission port 5 and is guided through the second focus lens 7 to be a concave surface. The laser beam 10 that has reached is applied to the glass plate 9 through the total reflection coating layer.

  At this time, as shown in FIG. 2, the laser beam 10 irradiated to the glass plate 9 and incident from the light incident surface 11 of the glass plate 9 toward the object point P on the optical axis X is refracted by the light incident surface 11. Then, the light is condensed at the image point P ′ on the optical axis X at a position approximately ½ of the thickness of the glass plate 9, and further toward the light reflection processing surface 2 of the reflecting mirror plate 3.

  The laser beam 10 reaching the light reflection processing surface 2 is reflected by the light reflection processing surface 2 and returns to the concave surface of the second focus lens through the same optical path in the glass plate 9 and in the atmosphere.

  As described above, the total reflection coating is applied to the concave surface of the second focus lens, and the laser beam 10 that has returned to the concave reflection surface 13 of the second focus lens is totally reflected by the concave reflection surface 13 and thus has the same optical path. Follow the direction toward the glass plate 9.

  As described above, the laser beam 10 irradiated from the laser emission port 5 and reaches the second focus lens 7 via the first focus lens 6, the concave reflecting surface 13 of the second focus lens 7 and the reflecting mirror plate 3. In the resonator structure formed between the light reflection processing surface 2 and the light reflection processing surface 2, the light is repeatedly condensed at a position substantially half the thickness of the glass plate 9 while being repeatedly reflected. Therefore, thermal stress can be efficiently concentrated on the condensing part of the glass plate 9.

  Therefore, in order to establish such an optical system, the concave reflecting surface 13 of the second focus lens 7 is constituted by a spherical surface whose center is an object point P in the glass plate 9.

  The heating operation by the optical system of the laser beam is continuously performed on the glass plate 9 moving at a predetermined speed in a predetermined direction, and at the same time, a cooling operation for the heating unit performed immediately after the heating is also ejected from the ejection nozzle 8. This is continuously performed by spraying a cooling medium on the heating unit.

  As a result, a scribe line continuous to the glass plate can be formed by repeatedly performing the heating operation by the laser beam 10 and the cooling operation by the cooling medium from the surface of the moving glass plate 9.

  Then, in order to give a bending moment to a scribe line from the surface opposite to the laser beam 10 irradiation surface of the glass plate 9, pressure is applied manually or automatically, and the glass cutting process is completed by dividing into individual glass pieces.

  In the above embodiment, the optical head that emits the laser beam is fixed and the glass plate is moved. However, since the laser beam and the glass plate are required to move relative to each other, the glass plate is fixed. You may make it scan a laser beam, and you may make it scan a laser beam, moving a glass plate.

  FIG. 3 shows the state of thermal stress in the glass after the heating operation by irradiating the glass plate with a laser beam, and FIG. 4 shows the state after the cooling operation by spraying the cooling medium after irradiating the glass plate with the laser beam. It shows the state of thermal stress inside the glass.

  From FIG. 3, when the glass plate is irradiated with the laser beam, a compressive stress is generated on the glass plate toward the laser irradiating portion. By spraying the cooling medium from FIG. 4, the compressive stress remains inside the glass plate. In the vicinity of the surface, a tensile stress is generated outward from the cooling medium spray.

  As described above, since tensile stress is generated in the region where the compressive stress is generated, a stress strain based on each stress is generated, and a crack is generated in the thickness direction from the surface of the glass plate. By connecting, a scribe line is formed.

It is a side view which shows embodiment of this invention. Similarly, it is the elements on larger scale near glass irradiated with the laser beam of the embodiment of the present invention. Similarly, it is a conceptual diagram which shows the stress state of the glass plate which irradiated the laser beam in embodiment of this invention. Similarly, it is the conceptual diagram which shows the stress state of the glass plate which irradiated the cooling medium in embodiment of this invention. It is the schematic which shows the glass cutting method by the conventional laser.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stage 2 Light reflection processing surface 3 Reflective mirror plate 4 Optical head 5 Laser emission port 6 1st focus lens 7 2nd focus lens 8 Injection nozzle 9 Glass plate 10 Laser beam 11 Light emission surface 12 Atmosphere 13 Concave reflection surface

Claims (5)

  A glass cutting method using a laser having a step of forming a scribe line by irradiating a glass plate with a laser beam emitted from a laser oscillator, wherein the laser beam irradiated on the glass plate repeatedly reciprocates the glass plate A glass cutting method using a laser, wherein a thermal stress is locally generated on the glass plate.   The laser beam reciprocates while repeating reflection in the resonator structure of the resonator structure formed between the plane reflecting surface of the reflector plate arranged so as to sandwich the glass plate and the spherical reflecting surface of the lens. The method for cutting glass with a laser according to claim 1.   3. The glass cutting method using a laser according to claim 1, wherein the laser oscillator is a YAG laser oscillator that emits a laser beam having a wavelength of 1030 nm or 1064 nm.   A glass cutting device using a laser used in a process of forming a scribe line by irradiating a glass plate with a laser beam emitted from a laser oscillator, wherein the glass plate includes a plane reflecting surface of a reflector plate and a spherical reflecting surface of a lens. The laser beam applied to the glass plate is reciprocated in the resonator structure of the resonator structure formed between the plane reflecting surface of the reflecting mirror plate and the spherical reflecting surface of the lens while repeating reflection. Accordingly, the glass plate is repeatedly reciprocated to generate a thermal stress locally on the glass plate.   The laser cutting apparatus according to claim 4, wherein the laser oscillator is a YAG laser oscillator that emits a laser beam having a wavelength of 1030 nm or 1064 nm.

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