Intraoral scanner that compensates for optical inaccuracies

A system for performing intraoral scans, comprising:

• alight source to provide light;
• an optical system comprising a plurality of lenses disposed along an optical path of the light, wherein the optical system comprises focusing optics to perform focusing of the light onto a focal surface and to direct the light toward a three dimensional object to be imaged in an oral cavity, the focusing optics comprising at least one lens of the plurality of lenses, wherein the optical system is a non-telecentric optical system having a non-fixed magnification;
• a detector to measure returning light that is reflected off of the three dimensional object and directed back through the focusing optics;
• a translation mechanism to adjust a position of the at least one lens to displace the focal surface along an imaging axis defined by the optical path, wherein due at least in part to the optical system being a non-telecentric optical system, adjustment of the position of the at least one lens and displacement of the focal surface along the imaging axis causes changes in a magnification at the focal surface and an accompanying inaccuracy in measurements of the three dimensional object;
• and
• one or more processor to:
• generate measurement data comprising coordinates of a plurality of surface points of the three dimensional object based on the measured returning light, the coordinates for each surface point of the plurality of surface points comprising an x coordinate, a y coordinate and a z coordinate, wherein the coordinates for at least a subset of the plurality of surface points comprise inaccuracies caused by the changes in magnification at the focal surface;
• adjust the x coordinate and the y coordinate of one or more surface points from the subset of the plurality of surface points to correct the measurement data so as to remove the inaccuracies caused by the changes in magnification at the focal surface;
• and
• generate a three dimensional representation of the three dimensional object using corrected measurement data in which the inaccuracies caused by the changes in magnification at the focal surface have been removed.