Patent ID: 8687180

Claim:
A method of determining a focal position for an objective positioned at a measurement location of a sample holder in a microscopy imaging system, the method comprising: positioning the objective at a z-position along a Z-axis relative to the sample holder; moving the objective to a plurality of z-positions relative to the sample holder, the sample holder having a conditioned upper surface of the sample holder and the plurality of z-positions corresponding to a respective distance between the objective and the sample holder; projecting a focusing light beam onto the sample holder when the objective is located at individual z-positions in the plurality of z-positions, the objective focuses the focusing light beam on the sample holder; observing a reflected light beam resulting from reflection of the focusing light beam off the conditioned upper surface of the sample holder; observing a plurality of reflected light beams resulting from reflection of the focusing light beam off the reflective coating, where plurality of reflected light beams respectively correspond to the individual z-positions and respectively corresponding to a plurality of focus scores; determining which focus score in the plurality of focus scores is a maximum focus score; and identifying the z-position in the plurality of z-positions that corresponds to the maximum focus score as the focal position for the objective.