Shape measuring device, shape measuring method, and glass plate manufacturing method

1. A shape measuring device comprising:

a predetermined pattern disposed on one side or the other side facing a measurement object which is a transparent flat plate;

an image pick-up section that is configured such that respective reflected images of the predetermined pattern on a front face and back face of the measurement object is separated in a separation direction perpendicular to an extension direction of the predetermined pattern, the image pick-up section being configured to capture the reflected images of the predetermined pattern on the front face and back face of the measurement object to thereby generate an image including the respective reflected images on the front face and back face;

a calculating section that calculates an inclination angle of at least the front face or the back face from the reflected images captured by the image pick-up section on the basis of a positional relation between the measurement object, the predetermined pattern and the image pick-up section; and

a determining section that determines a shape of at least the front face or the back face on the basis of the inclination angle calculated, wherein

the predetermined pattern includes a plurality of elements, and one end and the other end of each element of the plurality of elements, which are formed in a direction perpendicular to the extension direction, are deviated from each other in the extension direction.

2. The shape measuring device according to claim 1 , wherein the each element of the plurality of elements is arranged repeatedly in the extension direction.

3. The shape measuring device according to claim 1 , wherein the each element of the plurality of elements is formed into a long shape.

4. The shape measuring device according to claim 1 , wherein, in a first element and second element of the plurality of elements, the first element and second element being adjacent to each other, the first element is formed so as to be deviated in a first direction which is one direction along the extension direction from one end to the other end of the first element, and the second element is formed so as to be deviated in a second direction which is the other direction along the extension direction from one end to the other end on the side of the first element.

5. The shape measuring device according to claim 1 , wherein the each element of the plurality of elements is formed so as to be separated from one another.

6. The shape measuring device according to claim 1 , wherein the predetermined pattern is formed into a sine wave shape by the plurality of elements.

7. The shape measuring device according to claim 1 , wherein the predetermined pattern has a first pattern string formed of the plurality of elements and a second pattern string disposed in parallel with the first pattern string, the second pattern string being linearly symmetrical with the first pattern string.

8. A shape measuring method comprising:

a first step of capturing respective reflected images of a predetermined pattern on a front face and back face of a measurement object as an image separated in a separation direction perpendicular to an extension direction of the predetermined pattern, the predetermined pattern being disposed on one side or the other side facing the measurement object which is a transparent flat plate;

a second step of calculating an inclination angle of at least the front face or the back face from the reflected images captured in the first step on the basis of a positional relation between the measurement object, the predetermined pattern and a position where the images have been captured; and

a third step of determining a shape of at least the front face or the back face on the basis of the inclination angle calculated, wherein

the predetermined pattern includes a plurality of elements, and one end and the other end of each element of the plurality of elements, which are formed in a direction perpendicular to the extension direction, are deviated from each other in the extension direction.

9. The shape measuring method according to claim 8 , wherein the each element of the plurality of elements is arranged repeatedly in the extension direction.

10. The shape measuring method according to claim 8 , wherein the each element of the plurality of elements is formed into a long shape.

11. The shape measuring method according to claim 8 , wherein, in a first element and second element of the plurality of elements, the first element and second element being adjacent to each other, the first element is formed so as to be deviated in a first direction which is one direction along the extension direction from one end to the other end of the first element, and the second element is formed so as to be deviated in a second direction which is the other direction along the extension direction from one end to the other end on the side of the first element.

12. The shape measuring method according to claim 8 , wherein the each element of the plurality of elements is formed so as to be separated from one another.

13. The shape measuring method according to claim 8 , wherein the predetermined pattern is formed into a sine wave shape by the plurality of elements.

14. A method for manufacturing a glass plate, comprising:

a melting step of melting a glass raw material to obtain molten glass; a forming step of forming the molten glass into a continuous plate-shaped glass ribbon; a slow-cooling step of gradually cooling the glass ribbon by moving the glass ribbon; a measuring step of measuring a shape of a front face of the glass ribbon; a cutting step of cutting the glass ribbon; and a controlling step of controlling slow-cooling conditions in the slow-cooling step on the basis of a measurement result in the measuring step, wherein

the measuring step is a step in which measurement is performed by using the shape measuring method according to claim 8 in which the glass ribbon is used as the measurement object.