Compact intraoral 3d scanner

Abstract

An apparatus for determining surface topography of a patient's teeth comprises a probe sized to be at least partially inserted into an intraoral cavity of the patient, a light source to output light; and a light focusing assembly. The light focusing assembly comprises a first lens, a second lens and a focus changing assembly comprising one or more additional lenses that shares an optical axis with the first lens and the second lens and being configured to focus the light to a plurality of external focal planes to illuminate the patient's teeth, wherein the focus changing assembly has a movement gain factor, and wherein as a result of the movement gain factor a change in separation between lenses of the focus changing assembly by a first distance results in a change in a focus setting by a second distance that is 2-10 times greater than the first distance. The apparatus further comprises a detector configured to measure one or more characteristics of incident light returning from the illuminated patient's teeth and a processor coupled to the detector and configured to generate data representative of a topography of the patient's teeth based on the one or more measured characteristics of the incident light returning from the illuminated patient's teeth.