Patent ID: 8134719

Claim:
An apparatus for obtaining 3-D surface contour image data of a tooth, comprising: a double telecentric optical system configured to form an image of a surface of the tooth onto an image detector array; a focus adjustment mechanism actuable to adjust a position of either or both the double telecentric optical system and the image detector array along an optical axis to each of a sequence of focus positions; and a control logic processor in control signal communication with the focus adjustment mechanism to adjust focus position, and in image data communication with the image detector array for receiving image data obtained by the image detector array and with a memory for storing the received image data corresponding to each of the sequence of focus positions, wherein the control logic processor is configured to determine, for each of a plurality of pixels in the received image data, a corresponding depth value according to pixel contrast, wherein the control logic processor is further responsive to stored instructions for computing the 3-D surface contour image data from the stored image data.