Inclination sensor and surveying instrument using the same

Abstract

The present invention relates to an inclination sensor which utilizes a liquid member having a free surface. A first optical system collimates light emitted from a light source, a dark field pattern allows the light from the first optical system to pass therethrough, a half mirror changes the direction of the light which has passed through the scale pattern, a first liquid member having a free surface reflects the pattern light thus changed its direction by the half mirror, a second optical system focuses the pattern light reflected by the first liquid member, a light receiving means receives a light image formed by the second optical system, and a processing means calculates an inclination on the basis of a reception signal provided from the light receiving means. The scale pattern is formed by a plurality of slits, and the half mirror is disposed on an optical path of both the liquid member and the second optical system.

Dependencies are inferred from the claim text.