JP2015034095A - Method for cutting strengthened glass plate, and strengthened glass plate cutting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strengthened glass plate cutting method for cutting a strengthened glass plate by using a laser beam, without degrading the quality.SOLUTION: A cutting method in one mode of the invention cuts a strengthened glass plate 10 having a surface layer and a back layer having a residual compression stress, and an intermediate layer having a residual tensile stress, by moving the radiation range of a laser beam. At the cutting time, the irradiation energy of the laser beam per unit irradiation area on the strengthened glass plate is increased in the section from the near side of a crack occurrence position 43 to a cut ending point 42.

Description

  The present invention relates to a method for cutting a tempered glass sheet and a tempered glass sheet cutting apparatus.

  In recent years, in a portable device such as a mobile phone or a PDA, a cover glass (protective glass) is often used in order to enhance the protection and aesthetics of a display (including a touch panel). A glass substrate is widely used as a display substrate.

  On the other hand, the reduction in thickness and weight of portable devices has progressed, and the glass used in portable devices has become thinner. Since the strength decreases as the glass becomes thinner, tempered glass having a front surface layer and a back surface layer in which compressive stress remains has been developed to compensate for the insufficient strength of the glass. Tempered glass is also used as automotive window glass and architectural window glass.

  The tempered glass is produced by, for example, an air cooling tempering method or a chemical tempering method. The air cooling strengthening method rapidly cools the glass near the softening point from the front and back surfaces, and creates a temperature difference between the front and back surfaces of the glass and the inside, so that the surface layer and back surface layer where compressive stress remains is formed. Form. On the other hand, in the chemical strengthening method, the surface and the back surface of the glass are ion-exchanged, and ions having a small ion radius (for example, Li ions and Na ions) contained in the glass are replaced with ions having a large ion radius (for example, K ions). By doing so, the front surface layer and the back surface layer in which the compressive stress remains are formed. In either method, an intermediate layer in which tensile stress remains is formed between the front surface layer and the back surface layer as a reaction.

  When producing tempered glass, it is more efficient to temper a glass larger than the product size and then cut and take multiple faces rather than tempering glass of product size one by one. Therefore, as a method of cutting the tempered glass plate, a method of cutting the tempered glass plate by irradiating the surface of the tempered glass plate with laser light and moving the laser light irradiation area on the surface of the tempered glass plate is proposed. (See Patent Document 1 and Patent Document 2).

JP 2008-247732 A International Publication No. 2010/126977

  When cutting a tempered glass plate using laser light, it is necessary to optimize the conditions of the laser light applied to the tempered glass plate. In other words, if the conditions of the laser light applied to the tempered glass plate are inappropriate, the crack extends in an unintended direction, the cutting line deviates from the planned cutting line, and the quality of the tempered glass plate after cutting deteriorates. There was a problem.

  In view of the above problems, an object of the present invention is to provide a method of cutting a tempered glass plate and a tempered glass plate cutting device that cut a tempered glass plate using a laser beam without deteriorating the quality.

The method for cutting a tempered glass sheet according to the first aspect of the present invention includes a surface layer and a back surface layer in which compressive stress remains, and an intermediate layer formed between the surface layer and the back surface layer, in which tensile stress remains. The tempered glass plate is cut by moving the irradiation region of the laser beam irradiated to the tempered glass plate, wherein the tempered glass plate and the laser beam are the laser Assuming that the absorption coefficient of the tempered glass plate for light is α (cm ⁻¹ ) and the thickness of the tempered glass plate is t (cm), the formula 0 <α × t ≦ 3.0 is satisfied, When cutting the tempered glass sheet so as to have an acute angle with respect to the side surface toward the cutting end point located on the side surface, the cutting is performed from a predetermined position before a predetermined distance from the cutting end point of the tempered glass sheet. In the section to the end point The irradiation energy of the laser light per unit irradiation area irradiated to the tempered glass plate is made larger than the irradiation energy of the laser light per unit irradiation area required when cutting the tempered glass plate linearly, It is a cutting method of a tempered glass board.

  The method for cutting a tempered glass sheet according to a second aspect of the present invention is the above-described method for cutting a tempered glass sheet, wherein the predetermined position before a predetermined distance from the end point of cutting is directed to the side surface of the tempered glass sheet. This is just before the crack generation position where an unintended crack occurs.

  The method for cutting a tempered glass sheet according to the third aspect of the present invention is the above-described method for cutting a tempered glass sheet, wherein a line segment connecting the scanning position of the laser beam and the cutting end point, a side surface of the tempered glass sheet, The smaller the angle formed, the larger the irradiation energy of the laser light per unit irradiation area irradiated on the tempered glass plate.

  The method for cutting a tempered glass sheet according to the fourth aspect of the present invention is the above-described method for cutting a tempered glass sheet, in which the moving speed of the irradiation region of the laser beam is slowed down so that the laser beam per unit irradiation area is reduced. Increase the irradiation energy.

  The method for cutting a tempered glass sheet according to the fifth aspect of the present invention is the above-mentioned method for cutting a tempered glass sheet, wherein the laser beam output energy per unit irradiation area is increased by increasing the output of the laser beam. To do.

  The method for cutting a tempered glass sheet according to a sixth aspect of the present invention is the above-described method for cutting a tempered glass sheet, in which the area of the laser light irradiation region is reduced, thereby irradiating the laser light per unit irradiation area. Increase energy.

  The tempered glass sheet cutting method according to the seventh aspect of the present invention is the above-described tempered glass sheet cutting method, wherein the laser beam irradiation energy per unit irradiation area as the absorption coefficient α of the tempered glass sheet increases. Make it smaller.

  The tempered glass sheet cutting method according to the eighth aspect of the present invention is the above-described tempered glass sheet cutting method, wherein the laser beam irradiation energy per unit irradiation area increases as the thermal expansion coefficient of the tempered glass sheet increases. Make it smaller.

  The tempered glass sheet cutting method according to the ninth aspect of the present invention is the above-described tempered glass sheet cutting method, wherein the laser beam irradiation energy per unit irradiation area is increased as the thickness of the tempered glass sheet increases. Enlarge.

  The method for cutting a tempered glass sheet according to the tenth aspect of the present invention is the above-described method for cutting a tempered glass sheet, further cooling the periphery of the laser light irradiation region.

  The tempered glass sheet cutting method according to the eleventh aspect of the present invention is the above-described tempered glass sheet cutting method, wherein at least one of the front surface and the rear surface of the tempered glass plate is cooled around the laser light irradiation region. To do.

  A tempered glass sheet cutting method according to a twelfth aspect of the present invention is the above-described tempered glass sheet cutting method, wherein the periphery of the laser light irradiation region is cooled by blowing gas from a nozzle.

  A tempered glass sheet cutting apparatus according to a thirteenth aspect of the present invention includes a surface layer and a back surface layer in which compressive stress remains, and an intermediate layer formed between the surface layer and the back surface layer in which tensile stress remains. A tempered glass plate cutting device for cutting a tempered glass plate by moving an irradiation area of a laser beam applied to the tempered glass plate, the tempered glass plate being held and the tempered glass plate being predetermined A glass holding and driving unit that moves in the direction of the laser, a laser output unit that outputs laser light for cutting the tempered glass plate, and a control unit that controls the glass holding and driving unit and the laser output unit based on a control program; A control program generating unit that generates the control program, and the control program generating unit is directed toward a cutting end point located on a side surface of the tempered glass sheet. When cutting the tempered glass sheet so as to have an acute angle with respect to the side surface, the tempered glass in a section from a predetermined position before a predetermined distance from the cutting end point of the tempered glass sheet to the cutting end point. A control program is generated so that the irradiation energy of the laser beam per unit irradiation area irradiated on the plate is larger than the irradiation energy of the laser beam per unit irradiation area necessary for cutting the tempered glass plate in a straight line. To do.

  According to the present invention, it is possible to provide a tempered glass sheet cutting method and a tempered glass sheet cutting apparatus that cut a tempered glass sheet using laser light without degrading quality.

It is sectional drawing of a tempered glass board. It is a figure which shows distribution of the residual stress of the tempered glass board shown in FIG. It is a figure for demonstrating the cutting method of a tempered glass board. It is sectional drawing along the AA line of FIG. It is sectional drawing along the BB line of FIG. It is a figure for demonstrating the cutting method of the tempered glass board concerning embodiment. It is a figure which shows an example of the cutting | disconnection state of a tempered glass board when the conditions of the laser beam irradiated to a tempered glass board are improper. It is a figure which shows an example of the cutting state of the tempered glass board at the time of using the cutting method of the tempered glass board concerning this Embodiment. It is a figure which shows the other example of the cutting | disconnection state of a tempered glass board when the conditions of the laser beam irradiated to a tempered glass board are improper. It is a figure which shows the other example of the cutting | disconnection state of a tempered glass board at the time of using the cutting method of the tempered glass board concerning this Embodiment. It is a figure which shows the other example of the cutting | disconnection state of a tempered glass board when the conditions of the laser beam irradiated to a tempered glass board are improper. It is a figure which shows the other example of the cutting | disconnection state of a tempered glass board at the time of using the cutting method of the tempered glass board concerning this Embodiment. It is sectional drawing for demonstrating the cooling nozzle used for the cutting method of the tempered glass board concerning embodiment. It is a figure for demonstrating the effect of the cooling in the cutting method of the tempered glass board concerning embodiment. It is a figure for demonstrating the effect of the cooling in the cutting method of the tempered glass board concerning embodiment. It is a figure for demonstrating the cutting device of the tempered glass board concerning embodiment. It is a figure for demonstrating the cutting method of a tempered glass board. It is a figure for demonstrating the cutting method of a tempered glass board. It is a table | surface which shows the relationship between the irradiation energy of a laser beam per unit irradiation area, and a convex amount. It is a graph which shows the relationship between the irradiation energy of a laser beam per unit irradiation area, and a convex amount. It is a table | surface which shows the relationship between the presence or absence of cooling of a tempered glass board, and a convex amount.

  Embodiments of the present invention will be described below with reference to the drawings. First, the structure of the tempered glass plate and the principle of the method for cutting the tempered glass plate will be described.

  FIG. 1 is a cross-sectional view of a tempered glass sheet, and FIG. 2 is a diagram showing a distribution of residual stress in the tempered glass sheet shown in FIG. In FIG. 1, the direction of the arrow indicates the direction in which the stress is applied, and the size of the arrow indicates the magnitude of the stress.

  As shown in FIG. 1, the tempered glass plate 10 includes a front surface layer 13 and a back surface layer 15 where compressive stress remains, and an intermediate layer 17 provided between the front surface layer 13 and the back surface layer 15 where tensile stress remains. Have As shown in FIG. 2, the compressive stress (> 0) remaining on the front surface layer 13 and the back surface layer 15 tends to gradually decrease from the front surface 12 and the back surface 14 of the tempered glass plate 10 toward the inside. Further, the tensile stress (> 0) remaining in the intermediate layer 17 tends to gradually decrease from the inside of the glass toward the front surface 12 and the back surface 14.

In FIG. 2, CS is the maximum residual compressive stress (surface compressive stress) (> 0) in the surface layer 13 and the back layer 15, and CT is the internal residual tensile stress in the intermediate layer 17 (average value of residual tensile stress in the intermediate layer 17). (> 0) and DOL indicate the thicknesses of the surface layer 13 and the back surface layer 15, respectively. CS, CT, and DOL can be adjusted with reinforced processing conditions. For example, when the air cooling strengthening method is used, CS, CT, and DOL can be adjusted by the cooling rate of the glass. In addition, when the chemical strengthening method is used, CS, CT, and DOL are ion-exchanged by immersing glass in a treatment liquid (for example, KNO ₃ molten salt), so the concentration, temperature, immersion time, etc. of the treatment liquid It is adjustable. The front surface layer 13 and the back surface layer 15 have the same thickness and the same maximum residual compressive stress, but may have different thicknesses or different maximum residual compressive stresses.

  FIG. 3 is a diagram for explaining a method of cutting a tempered glass sheet. As shown in FIG. 3, the surface 12 of the tempered glass plate 10 is irradiated with laser light 20, and the irradiation region 22 of the laser light 20 is moved (scanned) on the surface 12 of the tempered glass plate 10, thereby strengthening glass. Stress is applied to the plate 10 to cut the tempered glass plate 10.

  An initial crack is formed in advance at the cutting start position at the end of the tempered glass plate 10. The method for forming the initial crack may be a general method, for example, a cutter, a file, or a laser. In order to reduce the number of steps, the initial crack need not be formed in advance.

  On the surface 12 of the tempered glass plate 10, the irradiation region 22 of the laser light 20 is moved in a straight line shape or a curved shape along the planned cutting line from the end of the tempered glass plate 10 to the inside. Thereby, the crack 31 is formed toward the inner side from the end of the tempered glass plate 10, and the tempered glass plate 10 is cut. The irradiation region 22 of the laser beam 20 may be moved in a P-shape, and in this case, the end of the movement path intersects the middle of the movement path.

  The light source of the laser light 20 is not particularly limited. For example, a UV laser (wavelength: 355 nm), a green laser (wavelength: 532 nm), a semiconductor laser (wavelength: 808 nm, 940 nm, 975 nm), a fiber laser (wavelength: 1060 to 6060). 1100 nm), YAG laser (wavelengths: 1064 nm, 2080 nm, 2940 nm) and the like. There is no limitation on the oscillation method of the laser beam 20, and either a CW laser that continuously oscillates the laser beam or a pulse laser that intermittently oscillates the laser beam can be used. The intensity distribution of the laser beam 20 is not limited, and may be a Gaussian type or a top hat type.

Assuming that the absorption coefficient of the tempered glass plate 10 with respect to the laser beam 20 is α (cm ⁻¹ ) and the thickness of the tempered glass plate 10 is t (cm), the tempered glass plate 10 and the laser beam 20 have 0 <α × t ≦ When the expression of 3.0 is satisfied, the tempered glass plate 10 can be cut using not only the action of the laser beam 20 but also the extension of cracks due to the residual tensile stress of the intermediate layer 17. That is, under the above conditions, heating of the intermediate layer 17 in the irradiation region 22 of the laser beam 20 at a temperature below the annealing point controls the extension of the crack 31 generated in the tempered glass plate 10 by the residual tensile stress of the intermediate layer 17. Thus, the tempered glass plate 10 can be cut by the crack 31 caused by the residual tensile stress. The intermediate layer 17 is heated at a temperature below the annealing point because when the heating is performed above the annealing point, the glass becomes high temperature and a viscous flow easily occurs even in a short time during which the laser beam passes. This is because the compressive stress generated by the laser beam is relieved by this viscous flow.

Assuming that the intensity of the laser beam 20 before entering the tempered glass plate 10 is I ₀ and the intensity of the laser beam 20 when moved through the tempered glass plate 10 by a distance L (cm) is I, I = I ₀ × The expression exp (−α × L) holds. This equation is called Lambert-Beer's law.

  By making α × t greater than 0 and 3.0 or less, the laser beam 20 reaches the inside without being absorbed by the surface of the tempered glass plate 10. Can be heated. As a result, the stress generated in the tempered glass plate 10 changes from the state shown in FIG. 1 to the state shown in FIG. 4 or FIG.

  4 is a cross-sectional view taken along the line AA in FIG. 3 and includes a laser light irradiation region. 5 is a cross-sectional view taken along line B-B in FIG. 3, and is a rear cross section from the cross section shown in FIG. 4. Here, “rear” means the upstream side of the laser beam 20 in the scanning direction. 4 and 5, the direction of the arrow indicates the direction of the stress, and the length of the arrow indicates the magnitude of the stress.

  In the intermediate layer 17 in the irradiation region 22 of the laser beam 20, since the intensity of the laser beam 20 is sufficiently high, the temperature is higher than that of the surrounding area, and a tensile stress smaller than the residual tensile stress shown in FIGS. , Compressive stress occurs. In a portion where a tensile stress smaller than the residual tensile stress or a compressive stress is generated, extension of the crack 31 is suppressed. In order to reliably prevent the extension of the crack 31, it is preferable that a compressive stress is generated as shown in FIG.

  As shown in FIG. 4, the surface layer 13 and the back layer 15 in the irradiation region 22 of the laser beam 20 have a compressive stress larger than the residual compressive stress shown in FIGS. Extension is suppressed.

  In order to balance with the compressive stress shown in FIG. 4, a tensile stress is generated in the intermediate layer 17 in the cross section behind the cross section shown in FIG. 4, as shown in FIG. 5. This tensile stress is larger than the residual tensile stress, and the crack 31 is formed in a portion where the tensile stress reaches a predetermined value. The crack 31 penetrates from the front surface 12 to the back surface 14 of the tempered glass plate 10, and the cutting shown in FIG. 3 is a so-called full cut cutting.

  When the irradiation region 22 of the laser beam 20 is moved in this state, the tip position of the crack 31 moves so as to follow the position of the irradiation region 22. That is, in the cutting method shown in FIG. 3, when the tempered glass plate 10 is cut, the extension direction of the crack 31 is controlled by the tensile stress (see FIG. 5) generated behind the scanning direction of the laser beam, and the laser beam is irradiated. Using the compressive stress (see FIG. 4) generated in the region that has been cut, the crack 31 is cut while suppressing the extension. Therefore, it can suppress that the crack 31 remove | deviates from the cutting planned line, and self-runs.

  Since high transparency is required for glass depending on the application, α × t is preferably closer to 0 when the laser wavelength used is close to the wavelength region of visible light. However, since α × t is too small, the absorption efficiency is deteriorated. Therefore, it is preferably 0.0005 or more (laser light absorption rate 0.05% or more), more preferably 0.002 or more (laser light absorption rate 0.2). % Or more), more preferably 0.004 or more (laser light absorption rate 0.4% or more).

  On the other hand, glass requires low transparency depending on the application. Therefore, when the used laser wavelength is close to the wavelength region of visible light, the larger α × t is better. However, if .alpha..times.t is too large, the surface absorption of the laser beam becomes large, and crack extension cannot be controlled. Therefore, α × t is preferably 3.0 or less (laser light absorptivity 95% or less), more preferably 0.1 or less (laser light absorptivity 10% or less), and further preferably 0.02 or less (laser Light absorption rate is 2% or less).

The absorption coefficient (α) is determined by the wavelength of the laser light 20, the glass composition of the tempered glass plate 10, and the like. For example, the content of iron oxide (including FeO, Fe ₂ O ₃ and Fe ₃ O ₄ ) in the tempered glass plate 10, the content of cobalt oxide (including CoO, Co ₂ O ₃ and Co ₃ O ₄ ), As the content of copper oxide (including CuO and Cu ₂ O) increases, the absorption coefficient (α) in the near-infrared wavelength region near 1000 nm increases. Furthermore, the absorption coefficient (α) increases in the vicinity of the absorption wavelength of the rare earth atom as the content of the oxide of the rare earth element (for example, Yb) in the tempered glass plate 10 increases.

The absorption coefficient (α) in the near-infrared wavelength region near 1000 nm is set according to the application. For example, in the case of window glass for automobiles, the absorption coefficient (α) is preferably 3 cm ⁻¹ or less. In the case of building window glass, the absorption coefficient (α) is preferably 0.6 cm ⁻¹ or less. In the case of display glass, the absorption coefficient (α) is preferably 0.2 cm ⁻¹ or less.

  The wavelength of the laser beam 20 is preferably 250 to 5000 nm. By setting the wavelength of the laser beam 20 to 250 to 5000 nm, both the transmittance of the laser beam 20 and the heating efficiency by the laser beam 20 can be achieved. The wavelength of the laser beam 20 is more preferably 300 to 4000 nm, still more preferably 800 to 3000 nm.

  The content of iron oxide in the tempered glass plate 10 depends on the type of glass constituting the tempered glass plate 10, but in the case of soda lime glass, it is, for example, 0.02 to 1.0% by mass. By adjusting the content of iron oxide in this range, α × t in the near infrared wavelength region near 1000 nm can be adjusted to a desired range. Instead of adjusting the content of iron oxide, the content of cobalt oxide, copper oxide, or rare earth element oxide may be adjusted.

  Although the thickness (t) of the tempered glass board 10 is set according to a use, it is preferable that it is 0.01-0.2 cm. In the case of chemically strengthened glass, the internal residual tensile stress (CT) can be sufficiently increased by setting the thickness (t) to 0.2 cm or less. On the other hand, when the thickness (t) is less than 0.01 cm, it is difficult to subject the glass to chemical strengthening treatment. The thickness (t) is more preferably 0.03 to 0.15 cm, still more preferably 0.05 to 0.15 cm.

  By using the method described above, the tempered glass plate can be cut.

  Next, the cutting method of the tempered glass board concerning this Embodiment is demonstrated. FIG. 6 is a diagram for explaining a method of cutting a strengthened glass sheet according to the present embodiment. FIG. 6 is a view of the tempered glass plate 10 as viewed from above. Moreover, the broken line 48 shown in the tempered glass board 10 has shown the cutting cutting line at the time of cutting out the sample 40 from the tempered glass board 10 using the cutting method demonstrated above. The sample 40 is a quadrangle having four corner portions and a straight portion having a predetermined radius of curvature. Note that the sample 40 shown in FIG. 6 is an example, and the method for cutting a tempered glass plate according to the present embodiment can also be used when a sample having another arbitrary shape is cut out from the tempered glass plate 10.

  When the sample 40 is cut out from the tempered glass plate 10, the laser beam is scanned so as to pass through the planned cutting line 48. In other words, the laser beam scanning is started from the cutting start point 41, the laser beam is scanned along the planned cutting line 48 in the direction of the arrow shown in FIG. 6, and the laser beam scanning is ended at the cutting end point 42. At this time, initial cracks are formed in advance at the cutting start point 41, that is, at the end of the tempered glass plate 10. The initial crack can be formed by, for example, a cutter, a file, or a laser.

  Thus, when cutting a tempered glass board using a laser beam, it is necessary to optimize the conditions of the laser beam irradiated to a tempered glass board. In other words, if the conditions of the laser light applied to the tempered glass plate are inappropriate, the crack extends in an unintended direction, the cutting line deviates from the planned cutting line, and the quality of the tempered glass plate after cutting deteriorates. There is a problem.

  FIG. 7A is a diagram illustrating an example of a cutting state of the tempered glass plate when the condition of the laser light applied to the tempered glass plate is inappropriate, and is an enlarged view in the vicinity of the cutting end point 42 illustrated in FIG. 6. . As shown in FIG. 7A, when the laser beam condition is inappropriate, an unintended crack 46 from the crack generation position 43 toward the cutting line 44 when the laser beam is scanned along the planned cutting line 48. Extends. Here, solid lines (cut lines 44 and 45) in the figure indicate a state where the tempered glass plate is cut (penetrated from the front surface to the back surface of the tempered glass plate 10), and a broken line (scheduled cutting line 48). ) Shows a state where the tempered glass plate is not cut.

  That is, the cutting end point 42 shown in FIG. 7A is on the cutting line 44 that has already been cut. In other words, the cutting end point 42 is on the side surface of the tempered glass plate. If the laser beam condition is inappropriate, the laser beam is scanned from the crack generation position 43 toward the cutting line 44 while scanning the laser beam along the planned cutting line 48 toward the cutting end point 42. The crack 46 extends. For this reason, the convex part 49 is formed in the sample 40 cut out from the tempered glass board 10, and the quality of the tempered glass board after cutting (sample 40) deteriorates.

  As described above, when the tempered glass plate 10 is cut, the tensile stress generated behind the scanning direction of the laser beam using the compressive stress (see FIG. 4) generated in the region irradiated with the laser beam. Cutting is performed while suppressing the extension of cracks (see FIG. 5). Therefore, when the laser beam condition is inappropriate, it becomes impossible to control the extension direction of the crack due to the tensile stress generated backward in the scanning direction, and the unintended crack 46 extends from the crack generation position 43 toward the cutting line 44. In some cases, the cutting line deviates from the planned cutting line 48.

  FIG. 7B is a diagram illustrating an example of a cut state of the tempered glass sheet when the method for cutting the tempered glass sheet according to the present embodiment is used. In the method for cutting a tempered glass sheet according to the present embodiment, the tempered glass sheet is formed so as to have an acute angle α1 with respect to the cutting line 44 toward the cutting end point 42 located at the cutting line (side surface) 44 of the tempered glass sheet. When cutting, unit irradiation irradiated to the tempered glass plate in a section from the front of the crack generation position 43 (that is, a predetermined position before a predetermined distance from the cutting end point 42 of the tempered glass sheet) to the cutting end point 42. The laser beam irradiation energy per area is set larger than the normal irradiation energy. Here, the normal irradiation energy is, for example, the irradiation energy of the laser beam per unit irradiation area required when cutting a tempered glass plate in a straight line. The crack generation position 43 is a starting point of an unintended crack 46 extending toward the cutting line 44. The position of the crack generation position 43 changes depending on the cutting conditions of the tempered glass plate 10 (for example, the distance between the scanning position of the laser beam and the cutting line 44, the irradiation energy of the laser beam, etc.).

  Thus, by increasing the irradiation energy of the laser beam per unit irradiation area irradiated on the tempered glass plate, the tensile stress generated behind the scanning direction of the laser beam can be increased. Therefore, since the tempered glass plate 10 can be cut while accurately controlling the extension direction of the cracks in the rear of the scanning direction, the unintended crack 46 is prevented from extending from the crack generation position 43 toward the cutting line 44. be able to. Thereby, the sample 40 can be cut along the planned cutting line 48.

  At this time, the smaller the angle α1 formed by the line connecting the scanning position of the laser beam and the cutting end point 42 and the cutting line 44 (side surface of the tempered glass plate 10), the more unintended cracks 46 are directed toward the cutting line 44. It tends to occur. Therefore, for example, as the angle α1 decreases, the irradiation energy of the laser light per unit irradiation area irradiated on the tempered glass plate may be increased.

Further, the irradiation energy E (J / mm ² ) of the laser light per unit irradiation area is applied to the tempered glass plate 10 with the output of the laser light being P (W), the scanning speed of the laser light being v (mm / s). Assuming that the beam diameter of the laser beam is φ (mm), it can be expressed by the following equation.

E (J / mm ² ) = P (W) / (v (mm / s) × φ (mm)) Formula 1

That is, the irradiation energy E (J / mm ² ) of the laser light per unit irradiation area is the energy per area where the laser light scans the tempered glass plate 10 per unit time (1 second). Below, the irradiation energy of the laser beam per unit irradiation area is also described as unit energy.

For example, the irradiation energy E (J / mm ² ) of the laser light per unit irradiation area can be increased by slowing the moving speed (scanning speed) of the laser light irradiation area from the above formula 1. Further, by increasing the output of the laser beam, the irradiation energy E (J / mm ² ) of the laser beam per unit irradiation area can be increased. Further, by reducing the area of the laser light irradiation region (that is, the beam diameter φ), the laser light irradiation energy E (J / mm ² ) per unit irradiation area can be increased.

Moreover, in this Embodiment, you may make the irradiation energy E (J / mm < ² >) of the laser beam per unit irradiation area small as the absorption coefficient (alpha) of the tempered glass board 10 becomes large. When the absorption coefficient α is large, the energy absorbed by the tempered glass plate 10 increases, so that the laser beam irradiation energy E (J / mm ² ) per unit irradiation area can be reduced accordingly.

Further, the irradiation energy E (J / mm ² ) of the laser beam per unit irradiation area may be increased as the thickness t of the tempered glass plate increases. When the thickness t of the tempered glass plate is thick, it is necessary to increase the energy supplied to the tempered glass plate 10, so that the laser beam irradiation energy E (J / mm ² ) per unit irradiation area may be increased. preferable. Further, as the thermal expansion coefficient of the tempered glass plate 10 increases, the laser beam irradiation energy E (J / mm ² ) per unit irradiation area may be reduced. If the thermal expansion coefficient of the tempered glass plate 10 is large, the tensile stress generated behind the scanning direction of the laser beam increases, and accordingly, the irradiation energy E (J / mm ² ) of the laser beam per unit irradiation area is reduced accordingly. be able to.

  FIG. 8A is a diagram illustrating another example of the cut state of the tempered glass plate when the condition of the laser light applied to the tempered glass plate is inappropriate. In the example shown in FIG. 8A, the cutting end point 52 is disposed on the side surface 54 of the tempered glass plate 10. Further, the planned cutting line 58 toward the cutting end point 52 is a straight line. As shown in FIG. 8A, when the laser beam conditions are inappropriate, the laser beam is scanned along the planned cutting line 58 from the crack generation position 53 toward the side surface 54 of the tempered glass plate 10. Unintended crack 56 extends. For this reason, the convex part 59 is formed in the sample 50 cut out from the tempered glass board 10, and the quality of the tempered glass board after cutting (sample 50) deteriorates.

  FIG. 8B is a diagram showing another example of the cut state of the tempered glass sheet when the method for cutting the tempered glass sheet according to the present embodiment is used. In the method for cutting a tempered glass sheet according to the present embodiment, when the tempered glass sheet is cut so as to have an acute angle α2 with respect to the side surface 54 toward the cutting end point 52 located on the side surface 54 of the tempered glass sheet, cracks occur. In the section from the front of the generation position 53 to the cutting end point 52, the irradiation energy of the laser light per unit irradiation area irradiated to the tempered glass plate is made larger than the normal irradiation energy.

  Thus, by increasing the irradiation energy of the laser beam per unit irradiation area irradiated on the tempered glass plate, the tensile stress generated behind the scanning direction of the laser beam can be increased. Therefore, the tempered glass plate 10 can be cut while accurately controlling the extension direction of the cracks in the rear of the scanning direction, so that the unintended crack 56 is prevented from extending from the crack generation position 53 toward the side surface 54. Can do. Thereby, the sample 50 can be cut along the planned cutting line 58.

  At this time, an unintended crack 56 is generated toward the side surface 54 as the angle α2 formed by the line connecting the scanning position of the laser beam and the cutting end point 52 and the side surface 54 (side surface of the tempered glass plate 10) decreases. It becomes easy. Therefore, for example, as the angle α2 decreases, the irradiation energy of the laser light per unit irradiation area irradiated on the tempered glass plate may be increased. 8A and 8B, since the planned cutting line 58 is a straight line, the angle α2 can also be expressed as an angle formed by the planned cutting line 58 and the side surface 54.

  FIG. 9A is a diagram illustrating another example of the cut state of the tempered glass plate when the condition of the laser light applied to the tempered glass plate is inappropriate. FIG. 9A is a view of the tempered glass plate 10 as viewed from above. When cutting the sample 60 from the tempered glass plate 10, scanning of the laser beam is started from the cutting start point 61, the laser beam is scanned along the planned cutting line in the direction of the arrow shown in FIG. The laser beam scanning ends.

  As shown in FIG. 9A, when the laser beam condition is inappropriate, an unintended crack 66 from the crack generation position 63 toward the cutting line 64 when the laser beam is scanned along the planned cutting line 68. Extends. For this reason, the convex part 69 is formed in the sample 60 cut out from the tempered glass board 10, and the quality of the tempered glass board after cutting (sample 60) deteriorates.

  FIG. 9B is a diagram showing another example of the cut state of the tempered glass sheet when the method for cutting the tempered glass sheet according to the present embodiment is used. In the method for cutting a tempered glass sheet according to the present embodiment, the tempered glass sheet is formed so as to have an acute angle α3 with respect to the cutting line 64 toward the cutting end point 62 located at the cutting line (side surface) 64 of the tempered glass sheet. When cutting, the irradiation energy of the laser beam per unit irradiation area irradiated to the tempered glass plate is set larger than the normal irradiation energy in the section from the front of the crack generation position 63 to the cutting end point 62.

  Thus, by increasing the irradiation energy of the laser beam per unit irradiation area irradiated on the tempered glass plate, the tensile stress generated behind the scanning direction of the laser beam can be increased. Therefore, since the tempered glass plate 10 can be cut while accurately controlling the extension direction of the cracks in the rear of the scanning direction, the unintended crack 66 is prevented from extending from the crack generation position 63 toward the cutting line 64. be able to. Thereby, the sample 60 can be cut along the planned cutting line 68. At this time, in the example shown in FIG. 9B, the angle α3 formed by the cutting line 67 and the cutting line 64 (in this case, the tangent to the cutting line 64) decreases as the scanning position of the laser beam approaches the cutting end point 62.

  In addition, the example shown in FIGS. 6-9 is an example, and the cutting method of the tempered glass board concerning this Embodiment is on the side of a tempered glass board toward the cutting end point located in the side of a tempered glass board. On the other hand, it can be widely applied when cutting a tempered glass plate so as to have an acute angle.

  With the method for cutting a tempered glass sheet according to the present embodiment described above, the tempered glass sheet can be cut using laser light without deteriorating the quality.

  Moreover, in the cutting method of the tempered glass board concerning this Embodiment, when scanning a laser beam and cut | disconnecting a tempered glass board, you may make it scan a laser beam, cooling a tempered glass board. FIG. 10 is a cross-sectional view for explaining a cooling nozzle used in the method for cutting a strengthened glass sheet according to the present embodiment. As shown in FIG. 10, the cooling nozzle 28 is formed with a tapered cavity so that gas flows inside the cooling nozzle 28. At this time, the tapered cavity is sized so that the laser light 20 collected by the lens 25 can pass through the inside of the cooling nozzle 28. Further, the cooling nozzle 28 is configured to be able to move in synchronization with the movement of the irradiation region of the laser beam (that is, at the same scanning speed as the laser beam).

  As a gas used for cooling, for example, air or nitrogen can be used. Further, in order to increase the cooling capacity, a mist containing minute moisture in the gas may be included. Further, as the gas used for cooling, a gas having a temperature lower than the ambient temperature at which the tempered glass plate is cut may be used. Further, as the gas used for cooling, a gas having a heat transfer coefficient larger than that of air may be used.

  The diameter φ1 of the opening at the tip of the cooling nozzle 28 and the distance Gap between the tip of the cooling nozzle 28 and the surface 12 of the tempered glass plate 10 can be arbitrarily determined. Here, the smaller the diameter φ1 of the opening at the tip of the cooling nozzle 28, the faster the flow rate of the gas blown to the tempered glass plate 10, so that the cooling capacity on the surface 12 of the tempered glass plate 10 is improved. Moreover, the cooling capability in the surface 12 of the tempered glass board 10 improves, so that the distance Gap of the front-end | tip of the cooling nozzle 28 and the surface 12 of the tempered glass board 10 is small. The cooling nozzle 28 is supplied with a cooling gas from a gas supply unit (not shown), for example.

  As described above, when the laser beam is scanned to cut the tempered glass plate, the laser beam is scanned while cooling the tempered glass plate, so that the extension direction of the cracks in the rear of the scan direction can be controlled with higher accuracy. it can. Therefore, it can suppress more reliably that a crack remove | deviates from a cutting projected line at the time of a cutting | disconnection of a tempered glass board, and extends in an unintended direction.

  FIG. 11 is a diagram showing a distribution of stress generated in the central portion of the tempered glass plate 10 when the laser beam is scanned on the tempered glass plate 10 (no cooling). As shown in FIG. 11, a compressive stress 33 is generated in the laser light irradiation region 22 of the tempered glass plate 10. Further, a tensile stress 35 is generated at a position X2 at the rear in the scanning direction that is separated from the center X1 of the laser light irradiation region 22 by a distance D1. In the method for cutting a tempered glass plate according to the present embodiment, a tensile stress 35 generated by laser light irradiation is applied to the end of the crack 31 and a crack is generated using the compressive stress 33 acting on the laser light irradiation region 22. By suppressing the extension of the tempered glass plate 10, the extension direction of the crack 31 at the rear in the scanning direction is controlled while the tempered glass plate 10 is cut.

  FIG. 12 is a diagram showing a distribution of stress generated in the central part of the thickness of the tempered glass plate 10 when laser light is scanned on the tempered glass plate 10 (with cooling). Similarly in the case shown in FIG. 12, a compressive stress 33 is generated in the laser light irradiation region 22 of the tempered glass plate 10. Further, a tensile stress 35 is generated at a position X2 ′ in the scanning direction rearward from the center X1 of the laser light irradiation region 22 by a distance D2. In the case shown in FIG. 12, since the surface of the tempered glass plate 10 is cooled, the distance D2 between the position X1 where the compressive stress 33 is generated and the position X2 ′ where the tensile stress is generated is not cooled. In this case, the distance is shorter than the distance D1 (see FIG. 11). For this reason, when the surface of the tempered glass plate 10 is cooled, the position X1 where the compressive stress 33 is generated and the position X2 ′ where the tensile stress is generated can be brought closer to each other. It can be controlled with high accuracy. Therefore, it can suppress more reliably that a crack remove | deviates from a cutting projected line at the time of a cutting | disconnection of a tempered glass board, and extends in the direction which is not intended.

  In addition, although the said example demonstrated the case where the surface of the tempered glass board 10 was cooled, you may cool the back surface of the tempered glass board 10, and it is comprised so that both the surface and the back surface of the tempered glass board 10 may be cooled. May be. A cooling nozzle can also be used when the back surface of the tempered glass plate 10 is cooled.

  Next, a tempered glass sheet cutting apparatus for carrying out the method for cutting a tempered glass sheet according to the present embodiment described above will be described. FIG. 13 is a diagram for explaining the tempered glass sheet cutting device according to the present embodiment. A tempered glass sheet cutting apparatus 70 according to the present embodiment includes a laser output unit 71, a glass holding drive unit 72, a control unit 73, and a control program generation unit 74.

  The laser output unit 71 outputs a laser beam 20 for cutting the tempered glass plate 10. Examples of the light source of the laser beam 20 include a UV laser (wavelength: 355 nm), a green laser (wavelength: 532 nm), a semiconductor laser (wavelength: 808 nm, 940 nm, 975 nm), a fiber laser (wavelength: 1060 to 1100 nm), and a YAG laser. (Wavelength: 1064 nm, 2080 nm, 2940 nm) or the like can be used.

  Here, when near infrared laser light is used, it is necessary to add impurities such as Fe to the tempered glass plate in order to increase absorption in the near infrared. When an impurity having an absorption characteristic in the near infrared is added, it also affects the absorption characteristic in the visible light region, and thus may affect the color and transmittance of the tempered glass plate. In order to prevent this, a mid-infrared laser having a wavelength of 2500 to 5000 nm may be used as the light source of the laser light 20. In the wavelength range of 2500 to 5000 nm, absorption due to molecular vibration of the glass itself occurs, so that it is not necessary to add impurities such as Fe.

  The laser output unit 71 includes an optical system for adjusting the focal point of the laser light. The power of the laser beam (laser output), the beam diameter (focal point) of the laser beam, the timing of laser irradiation, and the like are controlled using the control unit 73. Further, the cooling nozzle 28 shown in FIG. 10 may be disposed in the laser light irradiation portion. In this case, the flow rate of the gas blown from the cooling nozzle can be controlled using the control unit 73.

  The glass holding / driving unit 72 holds the tempered glass plate 10 to be processed and moves the tempered glass plate 10 in a predetermined direction. That is, the glass holding drive unit 72 moves the tempered glass plate 10 so that the laser beam scans the planned cutting line of the tempered glass 10. The glass holding / driving unit 72 is controlled using the control unit 73. The glass holding / driving unit 72 may be fixed by adsorbing the tempered glass plate 10 to be processed using a porous plate or the like. Further, the glass holding / driving unit 72 may include an image detector for determining the position of the tempered glass plate 10. By providing the image detector for positioning, the processing accuracy of the tempered glass plate 10 can be improved.

  In the tempered glass sheet cutting apparatus 70 shown in FIG. 13, the tempered glass 10 is moved using the glass holding drive unit 72 so that the irradiation region of the laser light 20 moves on the tempered glass sheet 10. At this time, the laser output unit 71 is fixed. However, the irradiation region of the laser beam 20 may be moved on the tempered glass plate 10 by fixing the tempered glass plate 10 held by the glass holding / driving unit 72 and moving the laser output unit 71. Moreover, you may comprise so that both the tempered glass board 10 currently hold | maintained at the glass holding | maintenance drive part 72 and the laser output part 71 may move.

  The control unit 73 controls the laser output unit 71 and the glass holding drive unit 72 based on the control program generated by the control program generation unit 74.

  The control program generation unit 74 is tempered according to at least one of the thermal expansion coefficient of the tempered glass plate 10, the thickness, the absorption coefficient of the tempered glass plate with respect to laser light, and the residual tensile stress of the intermediate layer 17 of the tempered glass plate. A control program for controlling the irradiation energy of the laser beam per unit irradiation area irradiated on the glass plate is generated.

  In addition, when the control program generation unit 74 cuts the tempered glass plate so as to have an acute angle with respect to the side surface of the tempered glass plate toward the cutting end point located on the side surface of the tempered glass plate, the control program generation unit 74 starts from the front of the crack occurrence position. A control program is generated such that the irradiation energy of the laser light per unit irradiation area irradiated to the tempered glass plate is larger than the normal irradiation energy in the section up to the cutting end point. For example, the control program generation unit 74, based on the information on the planned cutting line and the position information (current position) of the laser beam, the area of the laser beam irradiation area (that is, the beam diameter φ), the output of the laser beam, and A control program for controlling the scanning speed of the laser beam is generated.

  Specifically, for example, the control program generation unit 74 sets the physical properties (thermal expansion coefficient, thickness, absorption coefficient of the tempered glass plate with respect to the laser beam, the intermediate layer 17 of the tempered glass plate) of the tempered glass plate 10 set in advance. The irradiation energy of the laser beam per unit irradiation area irradiated on the tempered glass plate when the straight portion is cut is determined according to the residual tensile stress and the like. Then, based on the determined unit energy, information on the planned cutting line, and position information (current position) of the laser beam, the area of the laser beam irradiation area (that is, the beam diameter φ), the output of the laser beam, and A control program for controlling the scanning speed of the laser beam is generated.

  As described above, the invention according to the present embodiment provides a tempered glass sheet cutting method and a tempered glass sheet cutting device that cut a tempered glass sheet using laser light without degrading quality. be able to.

<Example 1>
Embodiment 1 of the present invention will be described below. In Example 1 shown below, a tempered glass plate having a plate thickness of 0.8 mm, a surface compressive stress CS of 818 MPa, a thickness DOL of each of the front surface layer and the back surface layer of 27.4 μm, and a residual tensile stress CT of 30 MPa was used. .

  The residual tensile stress CT of the tempered glass plate was measured by measuring the surface compressive stress CS and the depth DOL of the compressive stress layer (surface layer and back layer) with a surface stress meter FSM-6000 (manufactured by Orihara Seisakusho). From the thickness t of the tempered glass plate, the following formula 2 was used for calculation.

  CT = (CS × DOL) / (t−2 × DOL) Equation 2

  In this example, a sample 80 having a shape shown in FIG. 14 (in the case of this example, 50 mm × 90 mm) was cut from the tempered glass plate 10. That is, when cutting the sample 80 from the tempered glass plate 10, scanning of the laser beam is started from the cutting start point 81, the laser beam is scanned along the planned cutting line 88 in the direction of the arrow shown in FIG. At the point 82, the scanning of the laser beam is finished. The radius of curvature of the corner portion of the sample 80 was R = 5 mm. In addition, an initial crack was formed in advance at the cutting start point 81 at the end of the tempered glass plate, and no scribe line was formed on the surface of the tempered glass plate. The light source of the laser light was a fiber laser (central wavelength band: 1070 nm).

  The beam diameter of the laser beam was 0.1 mm. The scanning speed of the laser beam was 5 mm / s in the straight section and 2.5 mm / s in the corner. Here, the corner portion includes a section from the front of the crack occurrence position 83 in FIG. 15 to the cutting end point 82. In this example, when the tempered glass plate was cut by scanning the laser beam, the laser beam was scanned while cooling the tempered glass plate using the cooling nozzle 28 shown in FIG. The diameter φ1 of the opening of the cooling nozzle used at this time was 2 mm, and the distance Gap between the cooling nozzle and the surface of the tempered glass plate 10 was 3 mm. The flow rate of air flowing through the cooling nozzle was 50 L / min.

  In this embodiment, the convex amount P1 of the convex portion 89 formed by the unintended crack 86 extending from the crack generation position 83 toward the cutting line 84 shown in FIG. 15 is measured, and the amount of the convex amount P1 is measured. Was used to evaluate the quality of the sample 80 cut from the tempered glass plate.

  In FIG. 16, the relationship between the irradiation energy (unit energy) per unit irradiation area in the corner part at the time of cut | disconnecting a tempered glass board, and a convex amount is shown. In this example, the unit energy of the laser beam was changed by changing the laser output to 40 W, 50 W, and 75 W, respectively. The unit energy of the laser beam was obtained by substituting each laser output (W), laser beam scanning speed (corner part) 2.5 mm / s, and beam diameter of 0.1 mm into the above equation 1.

As shown in FIG. 16, the sample No. in which the unit energy of the laser beam is 160 J / mm ² (laser output = 40 W). 1-No. In No. 3, the convex amounts were 0.4 mm, 0.5 mm, and 0.45 mm, respectively. Sample No. in which the unit energy of laser light is 200 J / mm ² (laser output = 50 W). 4-No. In No. 6, the convex amounts were 0.2 mm, 0.4 mm, and 0.25 mm, respectively. Sample No. in which the unit energy of the laser beam is 300 J / mm ² (laser output = 75 W). 7, no. In No. 8, the convex amounts were 0.15 mm and 0.1 mm, respectively.

  FIG. 17 shows the relationship between the unit energy of the laser beam and the convex amount of the convex portion 89. The graph shown in FIG. 17 is a graph in which the unit energy and the convex amount of each sample in the table of FIG. 16 are plotted. From the results shown in FIGS. 16 and 17, it was found that the convex amount of the convex portion 89 tends to decrease as the unit energy of the laser beam increases.

  That is, in the section from the front of the crack generation position 83 to the cutting end point 82, the tensile stress generated at the rear of the laser light scanning direction increases as the unit energy of the laser light applied to the tempered glass plate increases. It is considered that the greater the tensile stress generated in the rear of the scanning direction, the more accurately the crack extension direction in the rear of the scanning direction can be controlled, and thus the convex amount of the convex portion 89 decreases.

<Example 2>
Embodiment 2 of the present invention will be described below. In Example 2 shown below, a tempered glass plate having a plate thickness of 1.1 mm, a surface compressive stress CS of 716 MPa, a thickness DOL of each of the front surface layer and the back surface layer of 68.8 μm, and a residual tensile stress CT of 51 MPa was used. .

  Also in this example, a sample 80 having a shape shown in FIG. 14 (in the case of this example, 35 mm × 50 mm) was cut from the tempered glass plate 10. The light source of the laser light was a fiber laser (central wavelength band: 1070 nm). The beam diameter of the laser beam was 0.1 mm. The scanning speed of the laser beam was 5 mm / s in the straight section and 1 mm / s in the corner. Here, the corner portion includes a section from the front of the crack occurrence position 83 in FIG. 15 to the cutting end point 82.

  Further, in this example, an experiment was conducted with and without cooling the tempered glass plate when scanning with laser light. When cooling the tempered glass plate when scanning with laser light, the cooling nozzle 28 shown in FIG. 10 was used. The diameter φ1 of the opening of the cooling nozzle used at this time was 1 mm, and the distance Gap between the cooling nozzle and the surface of the tempered glass plate 10 was 2 mm. The flow rate of air flowing through the cooling nozzle was 15 L / min.

  Also in this example, the convex amount P1 of the convex portion 89 shown in FIG. 15 was measured, and the quality of the sample cut from the tempered glass plate was evaluated using the amount of the convex amount P1.

In FIG. 18, the relationship between the presence or absence of cooling of a tempered glass board and a convex amount is shown. In this embodiment, the laser output is 80 W, the scanning speed at the corner of the laser beam is 1 mm / s, and the beam diameter is 0.1 mm. The irradiation energy is 800 J / mm ² .

  As shown in FIG. In 9 (no cooling), the convex amount was 0.15 mm. In contrast, sample no. For 10 (with cooling), the convex amount was 0.1 mm. Therefore, the convex amount of the convex portion is reduced when the tempered glass plate is cooled when the laser beam is scanned. This is because when the surface of the tempered glass plate is cooled, the distance between the position where the compressive stress is generated (laser irradiation region) and the position where the tensile stress is generated (rear in the scanning direction of the laser beam) is shortened (see FIG. 12). This is considered to be because the extension direction of the cracks behind the scanning direction could be controlled more accurately.

  The present invention has been described with reference to the above-described embodiment and examples. However, the present invention is not limited only to the configuration of the above-described embodiment and examples, and the scope of the invention of the claims of the claims of this application Of course, various changes, modifications, and combinations that can be made by those skilled in the art are included.

DESCRIPTION OF SYMBOLS 10 Tempered glass plate 12 Surface 13 Surface layer 14 Back surface 15 Back surface layer 17 Intermediate layer 20 Laser beam 22 Irradiation area 25 Lens 28 Cooling nozzle 31 Crack 33 Compressive stress 35 Tensile stress 40, 50, 60 Sample 41, 61 Cutting start point 42, 52, 62, 82 Cutting end point 43, 53, 63, 83 Crack occurrence position 44, 54, 64, 84 Cutting line (side surface)
45, 55, 65 Cutting line 46, 56, 66, 86 Crack 48, 58, 68, 88 Planned cutting line 49, 59, 69, 89 Convex part 71 Laser output part 72 Glass holding drive part 73 Control part 74 Control program generation Part

Claims (13)

Laser light that irradiates the tempered glass plate with a tempered glass plate that is formed between the surface layer and the back surface layer where compressive stress remains and an intermediate layer that remains between the surface layer and the back surface layer. A method of cutting a tempered glass plate that is cut by moving the irradiation region of
The tempered glass plate and the laser beam are expressed as 0 <α × t ≦, where α (cm ⁻¹ ) is the absorption coefficient of the tempered glass plate with respect to the laser beam, and t (cm) is the thickness of the tempered glass plate. Satisfies the equation of 3.0,
When cutting the tempered glass plate so as to have an acute angle with respect to the side surface toward a cutting end point located on the side surface of the tempered glass plate, a predetermined distance before a predetermined distance from the cutting end point of the tempered glass plate In the section from the position to the cutting end point, the irradiation energy of the laser light per unit irradiation area irradiated to the tempered glass plate per unit irradiation area necessary for cutting the tempered glass plate linearly Make it larger than the irradiation energy of the laser beam,
Cutting method of tempered glass sheet.   The cutting | disconnection of the tempered glass board of Claim 1 which is the front of the crack generation | occurrence | production position where the said undesired crack generate | occur | produces toward the side surface of the said tempered glass board, the said predetermined position before the predetermined distance from the said cutting end point. Method.   The smaller the angle formed between the line connecting the scanning position of the laser beam and the cutting end point and the side surface of the tempered glass plate, the more the irradiation energy of the laser beam per unit irradiation area irradiated to the tempered glass plate. The method for cutting a strengthened glass sheet according to claim 1 or 2, wherein the glass sheet is enlarged.   The cutting method of the tempered glass board as described in any one of Claims 1-3 which enlarges the irradiation energy of the laser beam per said unit irradiation area by making the moving speed of the irradiation area | region of the said laser beam slow. .   The cutting method of the tempered glass board as described in any one of Claims 1-3 which enlarges the irradiation energy of the laser beam per said unit irradiation area by enlarging the output of the said laser beam.   The cutting method of the tempered glass board as described in any one of Claims 1-3 which enlarges the irradiation energy of the laser beam per said unit irradiation area by reducing the area of the said irradiation area | region of the laser beam.   The cutting method of the tempered glass board as described in any one of Claims 1-6 which makes irradiation energy of the laser beam per said unit irradiation area small as the absorption coefficient (alpha) of the said tempered glass board becomes large.   The cutting method of the tempered glass board as described in any one of Claims 1-7 which makes irradiation energy of the laser beam per said unit irradiation area small as the thermal expansion coefficient of the said tempered glass board becomes large.   The cutting method of the tempered glass board as described in any one of Claims 1-8 which enlarges the irradiation energy of the laser beam per said unit irradiation area as the thickness of the said tempered glass board becomes thick.   The method for cutting a tempered glass sheet according to any one of claims 1 to 9, wherein in the section, the periphery of the laser light irradiation region is further cooled.   The cutting method of the tempered glass board of Claim 10 which cools the circumference | surroundings of the irradiation area | region of the said laser beam in at least one of the surface of the said tempered glass board, and a back surface.   The cutting method of the tempered glass board of Claim 10 or 11 which cools the circumference | surroundings of the irradiation area | region of the said laser beam by spraying gas from a nozzle. Laser light that irradiates the tempered glass plate with a tempered glass plate that is formed between the surface layer and the back surface layer where compressive stress remains and an intermediate layer that remains between the surface layer and the back surface layer. A tempered glass sheet cutting device that cuts by moving the irradiation area of
While holding the tempered glass plate, a glass holding drive unit that moves the tempered glass plate in a predetermined direction,
A laser output unit for outputting a laser beam for cutting the tempered glass plate;
A control unit for controlling the glass holding drive unit and the laser output unit based on a control program;
A control program generation unit for generating the control program,
When the control program generation unit cuts the tempered glass plate so as to have an acute angle with respect to the side surface toward the cut end point located on the side surface of the tempered glass plate, the cutting end point of the tempered glass plate. When the irradiation energy of the laser beam per unit irradiation area irradiated to the tempered glass plate cuts the tempered glass plate linearly in a section from a predetermined position before a predetermined distance to the cutting end point. Generate a control program that is greater than the required laser beam irradiation energy per unit irradiation area.
Tempered glass sheet cutting device.

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