| 摘要 |
PURPOSE:To simplify measurement, and also to raise its accuracy by placing in parallel a substrate which has arranged an element to a position for dividing a part between gauge marks into (n) equal parts, and a moving plate which has arranged an element to a position for dividing a part between the gauge marks into (n)+ or -(m) equal parts by using a specified real number (m). CONSTITUTION:A part between gauge marks on a substrate 10 is divided into (n) equal parts by an optional integer (n) and an optical sensor 11 functioning as an element is arranged, and a part between gauge marks of the same distance of the part between said gauge marks on a moving plate 20 is divided into (n)+ or -(m) equal parts by using (m) which is a real number smaller enough than (n) except an integer, and a small hole functioning as an element is provided. Subsequently, uniform light is irradiated from the upper face side of the plate 20 and photodetected by the sensor 11 through a small hole 21, and a large variation in phase of a wave of an arrangement order successive variation of outputs of the sensor 11 is measured by fixing the plate 10 and moving minutely the plate 20. |
