摘要 |
An electro-optical device for generating data signals representing relative displacement between an aperture pattern in a reference plane and a reflective pattern in a measurement plane comprises a reference detector for sensing reference radiation directed towards the aperture pattern and a convolution detector for sensing the reference radiation reflected by the reflective pattern. The phase of a signal generated by the convolution detector is compared to the phase of a signal generated by the reference detector for generating the data signals defining the relative displacement between the aperture pattern and the reflective pattern.
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