| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure a vertex position of an object to be measured by using light. SOLUTION: In a distributed light generator 10, parallel light from a semiconductor laser (LD) 11 is transmitted through sinusoidal wave like diffraction grating 13, the sinusoidal wave like diffraction grating 13 is vibrated like a sinusoidal wave in a direction parallel with a cycle direction by a driver 14, and parallel light having a sinusoidal wave like intensity distribution vibrating like a sinusoidal wave is generated. The parallel light is irradiated on the object 21 to be measured, and by a lens 20 placed in a position separated a distance shorter than a focal length of the lens from a vertex of the object to be measured, diffracted light from the vertex of the object to be measured is separated from other light in a position separated a distance about 5 times of the focal length of the lens from the lens. A temporal change of diffracted light intensity is detected by a CCD image sensor 22, and it is converted into an electrical detection signal. A phase included in the detection signal is calculated, and the vertex position of the object to be measured is accurately determined from the phase. COPYRIGHT: (C)2003,JPO
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