| 摘要 |
PURPOSE:To reduce dead load of a stage as well as to aim at improvements in profitability for shift positioning and durability, by installing each reflector in two orthogonal cross guides driving the stage, making it reflect a laser beam, and detecting the beam at a guide position. CONSTITUTION:The laser beam emitted out of a laser length measuring instrument 11 is separated into its spectral components at a beam silitter 12 and radiated to each of reflectors X, Y, 7 and 8 via interferometers X, Y, 9 and 10, while the laser beam being radiated to the reflector X7 is reflected by the reflector X7 and received by a receiver X14 via the interferometer X9, so with this light receiving, a position in an X-axis of a stage 6 is detected. In addition, the the laser beam radiated to the reflector Y8 is as well received by a receiver Y15 whereby a position in a Y-axis of the stage 6 is detected and each detection value is processed, thus positioning for the stage 6 takes place. Doing like this, dead load of the stage is reduced, making inertia of the stage lower down to some extent, and wear in moving parts is therefore reduced so that assembling operation comes to being yet easier. |
