Fuji Photo Optical Co., Ltd.

Kazuyoshi Yamasaki

Motonori Kanaya

Toshikazu Akaogi

A subject positioning device for an interferometer includes a positioning mechanism for positioning a test surface within an axial extent of interference positions in the object beam path, which is less than double of a thickness of the subject, and at least one positioning lens placed between a beam splitter and the axial extent of interference positions in the object beam path with a focal point located within the axial extent of interference positions.

Subject positioning device for optical interferometer

In an optical apparatus utilizing moire fringes to inspect surface irregularities of a test object, a single light beam forms a light beam network in an optical sensor (28) such that the test object can be two-dimensionally detected, thereby preventing the test object from abnormally approaching a moire grating (12). The light beam is reflected between a pair of mirrors (50, 52) a plurality of times within an identical plane and then the optical sensor (28) detects the intensity of the light beam. The optical sensor (28) is disposed such that the light beam network is positioned directly below the moire grating (12). Accordingly, a test object (2) abnormally approaching the moire grating (12) can be two-dimensionally detected by the light beam network, thereby improving the accuracy in detection.

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Saitama-ken, Japan

Kazuyoshi Yamasaki