| 摘要 |
PROBLEM TO BE SOLVED: To prevent erroneous measurement caused by a false brightness point in height measurement using a laser beam to allow stable measurement. SOLUTION: This device is provided with plural height calculating parts 36 of which the each comprises a lens 32, a PSD element 34 and a height calculator 35. Height informations 39 from the respective height calculating parts 36 are compared each other by a determination device 51, and, when the erroneous height information 39 is contained, the informations are excluded from an object for information processing, or the correct height informations are determined out of the group of the height informations and are used as the object for the information processing to evade the erroneous measurement. In the correct height determination, respective differences are found among the height informations, an average value of the height informations is determined as correct height information when the respective differences are within a predetermined reference value. Alternatively, the minimum value in the height informations is used as the correct height information when that the erroneous height information is always larger than the correct height information is preliminarily confirmed by a geometric condition of a measured object 21. |
