METHOD OF MEASURING SIZE OF SHEET GLASS

PROBLEM TO BE SOLVED: To provide a method of measuring size of sheet glass capable of accurately measuring the size of the sheet glass fixed to an opaque base, the glass having corner faces rounded by chipping, chamfering, etc., at the marginal edge. SOLUTION: The measuring method irradiates corner vicinities of a sheet glass 2 from its surface 3 marginal edge to a first side face 4a with an illuminant light L, taking an image of the corner vicinities to detect the position of the first side face 4a of the glass 2, uses an electronic camera 12, similarly detects the position of a second side face 4c opposite to the first side face 4a, and measures the distance between the first and second side faces 4a, 4c to measure the size.