Extension of Scheimpflug principle in multi-line laser scanning measurement

Scheimpflug principle is a description of the geometric relationship between the orientation of the plane of sharp focus, the lens plane, and the image plane of an optical system, when the three planes intersect along a common line. Scheimpflug principle is widely applied in single line laser scanning measurement to extend the depth of field, however it is rarely utilized in multi-line laser scanning measurement. Therefore, we extend Scheimpflug principle to multi-line laser scanning measurement to enlarge the depth of field in a specific orientation and leverage its strengths of high measurement efficiency in the meanwhile. The two classic scenarios of multi-line laser are theoretically analyzed with the construction of measurement model. Our experimental results verify the measurement model and prove the increase of depth of field in the measurement direction.