| 摘要 |
PURPOSE:To enable detection of information on positions of an object to be measured with higher accuracy by preventing mistakes in the detection of rotation of the object to be measured regardless of the configuration accuracy of the object to be measured. CONSTITUTION:Pairs of detectors 1X, 2X and 1Y, 2Y are provided for detecting positions of an object to be measured in X and Y directions at different points. Information about positions of the object to be measured in the X and Y directions is detected using the detection output of at least one of the detectors for each direction and also rotation of the object to be measured is detected using the detection output of at least either of the pairs of detectors. |
