US 6,285,456 B1 · Dimension measurement using both coherent and white light interferometers

Abstract

An interferometer and method for performing preliminary and main measurements quickly and with high precision are provided. Laser light and white light are successively introduced to the same interferometer booth. Laser light is introduced from a laser light source, and the interference fringe with a reference mirror as a reference is detected using a CCD and a personal computer. By setting the interference fringe to a preset value, the position of a work is adjusted. White light from a halogen lamp is then introduced, a corner cube moving mount is moved, interference fringe with a reference mirror as a reference is detected, and preliminary measurement of the work is performed. Next, laser light is introduced, interference fringe with a reference mirror as a reference is detected, and the main measurement of the work is performed. Because the preliminary and main measurements are performed within the same interferometer booth, the number of steps is reduced and high precision preliminary measurement can be performed.

Claims11

Dependent claims

An interferometer for measuring dimension of a work using laser light interference comprising;

a laser light source,
a white light source,
a first optical assembly for introducing laser light from said laser light source onto a work and onto a first reference surface which acts as reference for laser light interference,
a second optical assembly for introducing white light from said white light source onto a work and onto a second reference surface which acts as reference for white light interference,
a work adjustment means for adjusting the slope of the work with respect to said first reference surface,
an interference fringe detecting means for detecting laser light interference fringe generated by said first optical assembly and white light interference fringe generated by said second optical assembly, and
a control means for controlling said first optical assembly, second optical assembly, work adjustment means, and interference fringe detecting means to successively perform a position adjustment of the work using laser light interference, preliminary measurement of the work using white light interference, and main measurement of the work using laser light.

4 more elements

Dependencies are inferred from the claim text.

Dimension measurement using both coherent and white light interferometers

Life of this patent

Dimension measurement using both coherent and white light interferometers

Life of this patent

Abstract

Claims11