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1. (WO1999006868) LIGHT PROJECTING METHOD, SURFACE INSPECTION METHOD, AND APPARATUS USED TO IMPLEMENT THESE METHODS

Pub. No.:    WO/1999/006868    International Application No.:    PCT/JP1998/002694
Publication Date: Feb 11, 1999 International Filing Date: Jun 18, 1998
IPC: G01B 11/255
G01B 11/30
G01N 21/88
Applicants: NEWCREATION CO., LTD.

HAGA, Kazumi

SAKAI, Motoshi

USHIYAMA, Zenta

Inventors: HAGA, Kazumi

SAKAI, Motoshi

USHIYAMA, Zenta

Title: LIGHT PROJECTING METHOD, SURFACE INSPECTION METHOD, AND APPARATUS USED TO IMPLEMENT THESE METHODS
Abstract:
A light projecting method suitable for observing the state of the surface of an object to be measured, a surface inspection method using this light projecting method, and an apparatus used to implement these methods. In a light projecting apparatus which projects light from a light source through a projection lens unit, the projection lens unit has a characteristic of vertical aberration caused by spherical aberration on the light source side of the projection lens unit such that the deviation from the paraxial image plane to the image forming point increases or decreases with the incidence height. The light source is outside a group of image forming points.