Device determining surface element inclination angle for the optical detection of form errors of a low order

US4763006A · kind A · utility

Assignee

• Optische Werke G. Rodenstock · DE

Inventors

• Norbert Rau · Ober-Ramstadt, DE
• Gerd Hübner · Stuttgart, DE
• Wolfgang Staiger · Stuttgart, DE
• Rainer Brodmann · Haar, DE
• Oskar Gerstorfer · Dachau, DE

Key dates

• Filing date: Dec 3, 1986
• Grant date: Aug 9, 1988
• Expiry date: Dec 3, 2006

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/952
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device is provided for the optical detection of form errors of a low order, for example of roughness. The device possesses a light source whose light probes the body to be examined and a light-receiving device for the light reflected by the body. The device is characterized by the fact that the light-receiving device consists of a number of light-receiving elements arranged in linear array and that an evaluation unit determines the inclination angle of the probed surface element of the body from all output signals of the light-receiving elements. Shifts in the core of the reflected light beam can be measured which are substantially below the width of a light-receiving element. The measuring results remain practically unaffected by form deviations of a higher order such as roughness etc.