| 摘要 |
PURPOSE:To accurately measure the facing distance between a head and a work with respect to any work by calculating distance data with an object based on luminescent spot positional data obtained by photodetecting from plural luminescent spots for measurement. CONSTITUTION:When the same processing is repeatedly performed on the work 5, for instance, there is a case where the facing position like a work 5' at the near position or a work 5'' at the distant position is changed. In this case, measuring light 26 from the 1st projector 10 indicates the luminescent spot 12, the luminescent point 12' and the luminescent point 12'' with respect to the work 5 at the facing distance of a reference, the work 5' at the near position and the work 5'' at the distant position respectively. Accordingly, since images by reflected beams of light 27, 27' and 27'' with respect to the respective luminescent spots 12, 12' and 12'' appear at the different positions on the 1st photodetector 11, inversely, the facing distance can be measured based on a principle of triangulation from the positions of the luminescent spots detected by the 1st photodetector 11. Moreover, the 2nd projector and the 2nd photodetector can also measure the facing distance by the same phenomena. In this way, the facing distance with the head with respect to various works can be accurately measured. |
