| 摘要 |
PURPOSE:To enable positioning with high accuracy while also shortening time by obtaining the positional inforamtions of marks on a first body and a second body by using an optical system with one focal-length variable lens and moving a stage according to the informations when a space between the bodies is adjusted at a desired value. CONSTITUTION:When a space between two parallel tabular bodies 2 and 3 is brought to a desired one, a projection-state detecting means 4 connected to a treater 6 and a focal-length variable lens 1 are operated, and positioning marks M2 and M3 for the upper tabular body 2 are detected. The means 4 and the lens 1 are worked again, a mark M1 for the tabular body 3 positioned to a lower section is detected, and a lower stage 5 on which the tabular body 3 is placed is moved vertically according to these positional informations M1-M3, thus controlling the space between the tabular bodies 2 and 3 to the desired one. Consequently, mechanical operation is reduced, and positioning extending over a wide range is enabled. |
