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AssigneeMitutoyo Corporation
InventorsSadayuki Matsumiya, Tatsuya Nagahama, Atsushi Usami
Estimating the term…
Disclosed is an interference objective lens unit, comprising: an objective lens; a beam splitter that splits the light transmitted through the objective lens into a reference optical path in which a reference mirror is provided and a measuring optical path in which the measuring object is placed, and that superposes the split lights to output interference light; a first holder that holds the objective lens and that is formed by material having a first linear expansion coefficient; and a second holder that holds the reference mirror and that is formed by material having a second linear expansion coefficient different from the first linear expansion coefficient, wherein when a usage environment temperature changes, a difference in the linear expansion coefficients between the first holder and the second holder corrects an optical path difference between the reference optical path and the measuring optical path.
An interference objective lens unit, comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
For measuring contours or curvatures: using interferometry
Arrangements for eliminating or compensation of measuring errors due to temperature or weight: due to temperature
Passive reduction of errors: by using common path configuration, i.e. reference and object path almost entirely overlapping
Passive reduction of errors: by particular optical compensation or alignment elements, e.g. dispersion compensation
About 5 years 4 months of term left · ends 16 Feb 2032 (estimated)
1. Field of the Invention
The present invention relates to an interference objective lens unit and a light-interference measuring apparatus using thereof.
2. Description of the Related Art
The present invention will more fully be understood by the following detailed description and the accompanying drawings, but those are only for description and are not intended to limit the scope of the present invention, wherein:
FIG. 1 shows an overall configuration of a three-dimensional shape measuring apparatus as the light-interference measuring apparatus of the first embodiment;
FIG. 2 shows a configuration of an interference objective lens unit in the three-dimensional shape measuring apparatus of FIG. 1;
Hereinafter, a three-dimensional shape measuring apparatus (hereinafter referred to as a shape measuring apparatus) as a light-interference measuring apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
First of all, the configuration of the shape measuring apparatus 1 is described.
As shown in FIG. 1, the shape measuring apparatus 1 includes a light emitting unit 10, an optical head unit 20, an interference objective lens unit 30, an image forming lens 41, an imaging unit 40, a drive mechanism unit 50, a display unit 60, a control unit 70 and a stage S for placing a measuring object (unit to be measured) W thereon.