Glass sheet processing method and glass sheet processing apparatus

Patent metadata

Field	Value
Publication number	US-2016009587-A1
Application number	US-201514862525-A
Country	US
Kind code	A1
Filing date	Sep 23, 2015
Priority date	Mar 26, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A glass sheet processing method is provided for irradiating a laser beam on a glass sheet and forming a cleavage in the glass sheet with thermal stress. If each of an irradiation area of the laser beam on the surface and an irradiation area of the laser beam on the back face of the glass sheet includes a peak position of a power density of the laser beam, each irradiation area has an asymmetrical power density distribution that is asymmetrical with respect to a reference line that passes through the peak position and is parallel to a moving direction of the peak position. If each irradiation area has no peak position, each irradiation area has an asymmetrical shape that is asymmetrical with respect to a reference line that passes through a centroid position of the irradiation area and is parallel to a moving direction of the centroid position.

First claim

What is claimed is:

1 . A glass sheet processing method comprising the steps of:
irradiating a laser beam on a glass sheet such that the laser beam is transmitted through the glass sheet from a surface to a back face of the glass sheet; moving an irradiating position of the laser beam with respect to the glass sheet; and forming a cleavage in the glass sheet with thermal stress that is generated by irradiating the laser beam; wherein the laser beam is emitted from a light source and is irradiated on the surface of the glass sheet to form an irradiation area of the laser beam on the surface, and the laser beam that has been transmitted through the surface of the glass sheet is irradiated on the back face of the glass sheet to form an irradiation area of the laser beam on the back face; wherein in a case where each irradiation area includes a peak position of a power density of the laser beam, each irradiation area is arranged to have an asymmetrical power density distribution that is asymmetrical with respect to a reference line that passes through the peak position of the irradiation area and is parallel to a moving direction of the peak position; and in a case where each irradiation area does not include a peak position of a power density of the laser beam, each irradiation area is arranged to have an asymmetrical shape that is asymmetrical with respect to a reference line that passes through a centroid position of the irradiation area and is parallel to a moving direction of the centroid position.

2 . The glass sheet processing method according to claim 1 , wherein
a product (α×M) of an absorption coefficient (α) (cm −1 ) of the glass sheet with respect to the laser beam and a moving distance (M) (cm) of the laser beam moving from the surface to the back face of the glass sheet is greater than 0 and is less than or equal to 3.0.

3 . The glass sheet processing method according to claim 1 , wherein
the irradiation areas of the laser beam on the surface and the back face of the glass sheet are formed by shielding a part of a light flux of the laser beam, and irradiating a remainder of the light flux of the laser beam on the glass sheet.

4 . The glass sheet processing method according to claim 1 , wherein
the laser beam emitted from the light source is focused by a focus lens and irradiated on the glass sheet, and the irradiation areas of the laser beam on the surface and the back face of the glass sheet are formed by arranging an optical axis of the focus lens and an optical axis of the laser beam entering the focus lens to be shifted from each other.

5 . The glass sheet processing method according to claim 1 , wherein
each of the irradiation areas of the laser beam on the surface and the back face of the glass sheet is arranged into an ellipse shape having a minor axis or a major axis that is diagonal with respect to a moving direction.

6 . The glass sheet processing method according to claim 1 , wherein
a wavelength of the laser beam is within a range from 250 nm to 5000 nm.

7 . The glass sheet processing method according to claim 1 , further comprising the steps of:
irradiating a heating light beam for heating the glass sheet at an irradiating position of the laser beam, and moving an irradiating position of the heating light beam with respect to the glass sheet along with the irradiating position of the laser beam with respect to the glass sheet.

8 . A glass sheet processing apparatus comprising:
a support for supporting a glass sheet; a light source for emitting a laser beam to be transmitted through the glass sheet from a surface to a back face of the glass sheet that is supported by the support; an optical system for irradiating the laser beam emitted from the light source on the glass sheet that is supported by the support; and an irradiating position moving unit that moves an irradiating position of the laser beam with respect to the glass sheet; wherein the glass sheet processing apparatus is configured to form a cleavage in the glass sheet with thermal stress that is generated by irradiating the laser beam; and wherein the optical system is configured to form an irradiation area of the laser beam on the surface of the glass sheet by irradiating the laser beam emitted from the light source on the surface, and form an irradiation area of the laser beam on the back face of the glass sheet by irradiating the laser beam that has been transmitted through the surface on the back face of the glass sheet; wherein in a case where each irradiation area includes a peak position of a power density of the laser beam, each irradiation is arranged to have an asymmetrical power density distribution that is asymmetrical with respect to a reference line that passes through the peak position of the irradiation area and is parallel to a moving direction of the peak position; and in a case where each irradiation area does not include a peak position of a power density of the laser beam, each irradiation area is arranged to have an asymmetrical shape that is asymmetrical with respect to a reference line that passes through a centroid position of the irradiation area and is parallel to a moving direction of the centroid position.

9 . The glass sheet processing apparatus according to claim 8 , wherein
the optical system includes a light shielding portion for shielding a part of a light flux of the laser beam emitted from the light source.

10 . The glass sheet processing apparatus according to claim 8 , wherein
the optical system includes a focus lens for focusing the laser beam emitted from the light source; and an optical axis of the laser beam entering the focus lens and an optical axis of the focus lens are shifted from each other.

11 . The glass sheet processing apparatus according to claim 10 , further comprising:
an optical axis position adjusting unit for adjusting a position of the optical axis of the focus lens with respect to the optical axis of the laser beam entering the focus lens.

12 . The glass sheet processing apparatus according to claim 8 , wherein
the optical system includes a cylindrical lens for focusing the laser beam emitted from the light source in a predetermined direction; and the optical system is configured to form the irradiation area of the laser beam that has an ellipse shape with a minor axis that is diagonal to a moving direction on each of the surface and the back face of the glass sheet that is supported by the support.

13 . The glass sheet processing apparatus according to claim 8 , further comprising:
a focusing position adjusting unit for adjusting a focusing position of the laser beam with respect to the glass sheet that is supported by the support.

14 . The glass sheet processing apparatus according to claim 8 , wherein
a wavelength of the laser beam is within a range from 250 nm to 5000 nm.

15 . The glass sheet processing apparatus according to claim 8 , further comprising:
a heating light source that emits a heating light beam for heating the glass sheet that is supported by the support; wherein the irradiating position moving unit moves an irradiating position of the heating light beam with respect to the glass sheet along with the irradiation position of the laser beam with respect to the glass sheet.

Assignees

• Asahi Glass Co Ltd

Inventors

• Saito Isao
• Nagata Takahiro

Classifications

• B23K26/361

  for deburring or mechanical trimming (B23K26/351 takes precedence) · CPC title

• B23K26/0006

  taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence) · CPC title

• B23K2103/30

  Organic materials · CPC title

• B23K26/50

  Working by transmitting the laser beam through or within the workpiece · CPC title

• B23K2103/54

  Glass · CPC title