| 摘要 |
PURPOSE:To make a device inexpensive, by using two cameras, catching two marks on an object on a transfer table each separately with each corresponding camera, and taking an important point of a rotary mechanism of a positioning table at a position apart in the radial direction form a turning center of the table. CONSTITUTION:Corresponding to each position of two marks 2 and 3 on an object, two cameras 4 and 5 are used so that even if a distance of these marks between two points is made larger to raise measuring accuracy in rotation, these is unnecessary to lower the camera's magnification, so that three axes of X, Y and theta all are possible to do highly accurate measurement, thus highly accurate alignment is performable. And, owing to a rotary mechanism of a positioning table 6, compensation of a tilt angle gets off with calculation of the value equivalent to a difference in the Y direction without using a trigonometric function, so that operation is simplifiable, and simultaneously since indexing an angle of high resolution becomes unnecessary, so that a simple device is realizable from the mechanical standpoint. Therefore, it can be made into such one that is inexpensive and that highly accurate. |
