Automated surface acquisition for a confocal microscope

Abstract

A method is described for obtaining an image of a target surface with a confocal microscope. The surface to be imaged is represented by a number of points on the surface, each of which has a unique location represented by X, Y, and Z Cartesian coordinates. The microscope selects a starting position for an objective lens of the microscope along a Z vector substantially normal to the surface. The objective lens has a preselected range of travel along the Z vector that is divided into a number of Z positions. Next, the objective lens is positioned and the surface scanned at each of the Z positions. The scan at each Z position provides signals, one for each point on the surface, representing the reflected intensity of laser light. Then, for each point on the surface, the microscope finds the Z coordinate of the point by determining which Z position resulted in the greatest return intensity of reflected laser light. From this information the Z coordinate of any particular point may be determined because the maximum reflected intensity for a given point, when correlated to the Z position of the objective lens, gives the Z location of that point on the surface. Having determined the Z locations for each point on the surface, the Z locations are compared to determine the low and high points on the surface. A second scan is then set up using the low and high points on the surface to determine the optimal scan parameters.