Glass plate production method, glass plate, glass article production method, glass article, and glass article production apparatus

1. A glass plate production method comprising:

irradiating a glass material which has a first main surface and a second main surface opposite to each other, with a laser to form an in-plane void region having a plurality of surface voids arranged on the first main surface and a plurality of internal void rows each having at least one internal void apart from a surface void arranged from the in-plane void region toward the second main surface of the glass material; and

chemically strengthening the glass material having the plurality of internal void rows formed therein by penetrating alkali metal ions to the glass material,

wherein the plurality of internal void rows are different from through holes formed so as to penetrate the glass material in a thickness direction of the glass material, and

the surface void and the at least one internal void in the internal void row are not continuous or connected to each other except via optional microcracks.

2. The glass plate production method according to claim 1 ,

wherein in the in-plane void region, an interval between adjacent voids falls within a range of 3 to 10 μm.

3. The glass plate production method according to claim 1 ,

wherein in the irradiating,

after the in-plane void region is formed by a first-pass laser irradiation, at least one laser irradiation is additionally repeated along the in-plane void region to form the plurality of internal void rows from the first main surface toward the second main surface of the glass material.

4. The glass plate production method according to claim 1 ,

wherein the irradiating further comprises

forming, after forming the in-plane void region, a groove along the in-plane void region in at least one of the first main surface and the second main surface; or

forming, before forming the in-plane void region, a groove along the in-plane void region in at least one of the first main surface and the second main surface along the in-plane void region formed thereafter.

5. A glass article production method comprising:

producing a glass plate by the glass plate production method according to claim 1 , the glass plate having a third main surface corresponding to the first main surface of the glass material and a fourth main surface corresponding to the second main surface of the glass material; and

separating one glass article, or two or more glass articles from the glass plate along the in-plane void region and the plurality of internal void rows.

6. The glass article production method according to claim 5 ,

wherein in the separating,

the one glass article or two or more glass articles are obtained by one or more processes selected from the group consisting of a) applying a pressing force along the in-plane void region to the glass plate, b) deforming the glass plate to convexly curve the third main surface or the fourth main surface, and c) applying a tensile stress to the glass plate due to thermal stress along the in-plane void region.

7. The glass plate production method according to claim 1 ,

wherein each of the plurality of the voids has a diameter of 1 to 5 μm.

8. The glass plate production method according to claim 1 ,

wherein the irradiating further comprises forming a plurality of surface voids on the second main surface such that each of the internal void rows has one surface void on the first main surface, at least one internal void and one surface void on the second main surface.