Shape measuring device, shape measuring method, and glass plate manufacturing method
View Patent ↗A shape measuring apparatus includes: an image pick-up section that captures an image of two reflection spot groups of a pattern reflected in a first surface M 1 and a second surface of a transparent flat plate and generates an image containing two reflection images separated in a direction perpendicular to a direction of extending; a first surface reflection spot group estimating section that estimates from the image a first surface reflection spot group of the pattern generated by the first surface of the transparent flat plate; an inclination angle calculating section that calculates an inclination angle of the first surface of the transparent flat plate at an estimated position of the first surface reflection spot group; and a surface shape determining section that determines a shape of the first surface of the transparent flat plate based on the calculated inclination angle.
1. A shape measuring method comprising the steps of:
by using an image pick-up section arranged such that an optical axis becomes perpendicular to a direction of extending of a linear pattern arranged above a transparent flat plate serving as a measurement object, capturing an image of two reflection spot groups of the pattern generated by a first surface and a second surface of the transparent flat plate and thereby generates an image containing two reflection images separated in a direction perpendicular to the direction of extending;
estimating from the image a first surface reflection spot group of the pattern in the first surface of the transparent flat plate by using a positional relation of the transparent flat plate, the pattern, and the image pick-up section;
calculating an inclination angle of the first surface of the transparent flat plate at a position of the estimated first surface reflection spot group by using the positional relation of the transparent flat plate, the pattern, and the image pick-up section; and
determining a shape of the first surface of the transparent flat plate based on the calculated inclination angle.
2. The shape measuring method according to claim 1 , wherein
the inclination angle calculating step calculates the inclination angle based on a condition that an incident angle of incident light travelling from the pattern toward the first surface reflection spot group is equal to a reflection angle of reflected light travelling from a position of the first surface reflection spot group toward the image pick-up section.
3. The shape measuring method according to claim 1 , wherein
the pattern is a pattern constructed such that a plurality of dots are arranged linearly in the extending direction.
4. The shape measuring method according to claim 1 , wherein
the transparent flat plate is conveyed in a direction perpendicular to the direction of extending.
5. A manufacturing method for glass plates comprising:
a melting step of melting raw material so as 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 in the course of conveying so as to remove stress;
a measurement step of measuring the surface shape of the glass ribbon;
a cutting step of cutting the glass ribbon; and
a control step of controlling slow cooling conditions in the slow cooling step based on a measurement result of the measurement step, wherein
the measurement step is a step in which measurement is performed on the glass ribbon by using the shape measuring method according to claim 1 .
6. A manufacturing method for glass plates comprising:
a melting step of melting raw material so as 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 in the course of conveying so as to remove stress;
a measurement step of measuring the surface shape of the glass ribbon;
a cutting step of cutting the glass ribbon; and
a control step of controlling slow cooling conditions in the slow cooling step based on a measurement result of the measurement step, wherein
the measurement step is a step in which measurement is performed on the glass ribbon by using the shape measuring method according to claim 2 .
7. A manufacturing method for glass plates comprising:
a melting step of melting raw material so as 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 in the course of conveying so as to remove stress;
a measurement step of measuring the surface shape of the glass ribbon;
a cutting step of cutting the glass ribbon; and
a control step of controlling slow cooling conditions in the slow cooling step based on a measurement result of the measurement step, wherein
the measurement step is a step in which measurement is performed on the glass ribbon by using the shape measuring method according to claim 3 .
8. A manufacturing method for glass plates comprising:
a melting step of melting raw material so as 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 in the course of conveying so as to remove stress;
a measurement step of measuring the surface shape of the glass ribbon;
a cutting step of cutting the glass ribbon; and
a control step of controlling slow cooling conditions in the slow cooling step based on a measurement result of the measurement step, wherein
the measurement step is a step in which measurement is performed on the glass ribbon by using the shape measuring method according to claim 4 .