Patent ID: 11287629

Abstract:
A method for determining a height position of an object at of using a microscope which images using a point-spread function along a z-direction (height direction), comprising the steps of imaging the object in the far field and determining a far-field intensity, calculating a maximum intensity expected by multiplying the far-field intensity by a scaling factor, partially confocally imaging the object with the focus in the z-direction within the depth-of-field range, and determining a partially-confocal intensity of the imaging, calculating the intensity of the point-spread function (at the first location) by forming a difference between the partially-confocal intensity and a product of the far-field intensity and a predefined combination factor, calculating the z-coordinate of the focus at a point-spread function maximum, using a previously-known form of the point spread function, its calculated intensity, and the calculated expected maximum intensity, and using the z-coordinate as the height position of the object.