| 摘要 |
PROBLEM TO BE SOLVED: To provide an interference type contactless measuring unit also capable of measuring the step or thickness of an object whose surface has a fine shape, such as paper, cloth, and rubber, to be measured and an object having a low reflection factor to be measured. SOLUTION: The interference type contactless measuring unit measures the step or thickness of the object to be measured by driving an objective lens for focusing on the surface of the object to be measured. The interference type contactless measuring unit comprises a light source 1 for irradiating the object 6 to be measured with light; a beam splitter 2 for dividing luminous flux from the light source 1 into the side of the object 6 to be measured and the side of a reference mirror 3; a first objective lens 4 provided between the beam splitter 2 and the object 6 to be measured; and a second objective lens 5 that is provided between the beam splitter 2 and the reference mirror 3 and at a position, where distance from the splitter 2 equals the first objective lens 4 and is homogeneous to the first objective lens 4; and the reference mirror 3 provided at the focus position of the second objective lens 5. There is provided a focusing mechanism 10 the focusing of which is made by interference fringes generated by the interference of reflected light from the object 6 to be measured and the reference mirror 3. COPYRIGHT: (C)2004,JPO |
