Patent EP-2378341-A1 (EP)
Inventor: BRILL NORBERT
IPC: G01N1/04
Filed: 2010-04-15
Abstract: The method comprises determining the focal position of a point on the surface of the sample support by focusing a microscope objective with a numerical aperture of NA1 on the point, positioning the micro-manipulation tool on an optical axis (5) of the microscope, determining the focal position of the micro-manipulation tool by focusing the microscope objective or a second microscope objective with the numerical aperture of NA2 that is less than the first numerical aperture on the tip of the micro-manipulation tool, and calculating a lowering height. The method comprises determining the focal position of a point on the surface of the sample support by focusing a microscope objective with a numerical aperture of NA1 on the point, positioning the micro-manipulation tool on an optical axis (5) of the microscope, determining the focal position of the micro-manipulation tool by focusing the microscope objective or a second microscope objective with the numerical aperture of NA2 that is less than the first numerical aperture on the tip of the micro-manipulation tool, calculating a lowering height in the light of predetermined tolerance profile, and positioning the micro-manipulation tool at the point by lowering the lowering height. The determining and calculating steps are repeated and i-microscopic objective is repeated by increasing numerical aperture. The tolerance of the manipulation tool and/or the sample holder is determined through the depth of field using i-th objective. The predetermined points on the surface of the sample holder is calculated, where the corresponding lowering height for each point is stored in a database and each point is calculated for determining the stored lowering height. Three points lying on straight points are identified on the surface of the sample holder from their focal positions, and a plane equation is calculated and the lowering height of any point is identified on the surface of the sample holder. The position of the tip of the manipulation tool is defined as focal position. A torsion angle and a tilt angle of the manipulation tool are calculated by determining the focal position of a first point (Q 1) on the top of the manipulation tool by focusing on the point, rotating the tool about its axis manipulation and adjusting the microscope objective to focus the focal position of the first point and a focal position of a second point that are present on the top of the manipulation tool, determining the focal position of a third point (Q 3) on the top of the manipulation tool by focusing on the point, tilting the tool about a manipulation of the sample holder parallel to the plane and axis adjusting the microscope objective to focus the point until the focal positions are equal, and setting the focal position of the manipulation tool. The focal position determines a point R on the surface of a storage vessel by first focusing the microscope objective at the R point. The points are moved on the surface of the sample holder and/or the storage vessel by a positioning table. The determination of the focal position is done using a distance measurement system.