| 摘要 |
PURPOSE:To obtain vernier-scale patterns provided with two kinds of required accuracies without changing the kind of vernier scale at each process and without forming a wide area for the vernier scale patterns by a method wherein two vernier scales whose scale is different are installed for one main scale. CONSTITUTION:The following are provided: main scales 10, 13; and first vernier scales 11, 14 and second vernier scales 12, 15 whose pitch is different from each other on both sides of the main scales 10, 13. The main scales 10 as well as the first vernier scales 11 and the second vernier scales 12 which are arranged on both sides of them are arranged intermittently at a prescribed pitch along the X-axis direction; the main scales 13 as well as the first vernier scales 14 and the second vernier scales 15 are arranged intermittently at a prescribed pitch along the Y-axis direction. When the individual pitches of the main scales 10, 13 as well as the first vernier scales 11, 14 and the second vernier scales 12, 15 are set, they are decided arbitrarily by the readout range and the readout accuracy of the vernier scales at two kinds of required processes. When this vernier pattern is used, the vernier scales of two kinds of required accuracies can be obtained without changing the vernier pattern at each process and without forming a wide region to form the vernier patterns. |
