| 摘要 |
<p>It is easily determined that a wafer is located to a predetermined measuring position, and then a measurement instruction is outputted to a sensor controller, whereby a measurement can be commenced. There are provided wafer rotating means (2); rotation determining means (3); light projecting means (9) for projecting light to the periphery of the wafer; CCD linear sensors (26) arranged in a line; and signal processing means (10, 17) for determining the positions of the edges of the wafer to determine at least one of the orientation flat position, notch position, and center position. There are provided an up/down counter (21a) that receives and converts a signal from the rotation determining means to rotational-position information; a measurement angle setting register (21b) that stores therein the rotational-position information during interval angle rotation; and a comparator (21c) that compares a set value of the measurement angle setting register with the count value of the up/down counter.</p> |
