BASAL PLATE DEFORMATION DETECTING SYSTEM AND DEFORMATION DETECTING METHOD

摘要

The subject matter is related to a deformation detecting system for inspecting and detecting deformations of a basal plate with front and rear flat surfaces that are in parallel with each other in a non-deformed state. The system is provided with supporting members (122A-122C) to support a basal plate (W) in a substantially horizontal standard position and first and second optical sensors. The first sensors (161) define a first optical path (L1) passing immediately over the front surface of the basal plate in the case that the basal plate is in a non-deformed state and is supported by the supporting members. The second sensors (162) define a second optical path (L2) passing immediately under the rear surface of the basal plate in the case that the basal plate is in a non-deformed state and is supported by the supporting members. The first and second sensors detect cutoffs of the first and second optical paths due to the subject basal plate supported by the supporting members, respectively. The system is provided with a deformation judging means (143) for judging deformations of the basal plate whether or not such deformations are larger in magnitude than the standard degree of deformations in accordance with detecting information of the optical sensors (161, 162).