Sätt och anordning för beröringsfri inmätning av förflyttning

摘要

The invention relates to a method and a device for measuring the linear movement of a surface (5; 14) of an object being measured. The surface of the object is illuminated by a laser plane (3; 10) with essentially parallel light. The laser plane (3; 10) generates a narrow laser line (4; 11) on the surface (5; 14) of the object. The laser line (4; 11) is essentially parallel with the direction of movement (6; v) of the surface (5; 14) of the object. The laser line (4; 11) is imaged on a matrix of photodetectors (7). A picture of the laser line (4; 11) is detected and stored. Thereafter a further picture is detected and stored. A correlation calculation is performed for different longitudinal movements between the two stored pictures of lines. The movement of the surface (5; 14) of the object is calculated based on the calculated correlation values.