| 摘要 |
PROBLEM TO BE SOLVED: To provide a punch character reader capable of reading even a punch character which is punched on a punch plane of a steel product which is in a red heat state of 600°C or higher.SOLUTION: A punch character reader is configured to: acquire S1 a three-dimensional distance map of a punch plane F by a regulated mesh resolution by a laser distance meter using laser beam having a wavelength shorter than a wavelength of green; calculate S2 a plane-state three-dimensional distance map containing a corrugation state to a height direction of the punch plane F based on the three-dimensional distance map; and specify S3 the mesh having distance equal to or more than a threshold, as a mesh having a recess, after comparing the three-dimensional distance map of the acquired punch plane F and the threshold, with the plane-state three-dimensional distance map of the punch plane F as a reference. After the mesh having a recess is specified, a punch character group is extracted S4 from an existence area of the mesh having a recess, then the punch character is extracted S5 based on continuity of the area having a recess (containing discontinuity), then the punch character is recognized S6 by comparing the extracted punch character and a character which has been stored in advance.SELECTED DRAWING: Figure 2 |
