| 摘要 |
<p>The invention provides a device for shifting the phase of a projected grating by the use of a grating generator (26) comprising one or more clear substrates (26A, 26B) having a plurality of equally-spaced, equal with bands of liquid crystal. The liquid crystal bands are selectively activated to modulate, that is, to shift, the phase of the projection of the grating on a test surface.</p> |
