Embodiments for estimating a surface texture of a tooth are described herein. One method embodiment includes collecting a sequence of images utilizing multiple light conditions using an intra-oral imaging device and estimating the surface texture of the tooth based on the sequence of images.

An intra-oral handheld 3D optical scanner includes an illumination module configured to generate an illumination signal to illuminate a dental object, and an image sensor configured to obtain data in response to the illumination of the dental object. The data is configured to be used to generate a 3D dental model of the dental object. The scanner also includes a lens housing including an optical lens that is configured to direct the illuminating signal towards the dental object, and a drive including a shaft that is configured to rotate around a rotation axis. The scanner also includes a guide extending continuously along at least a part of a length of the shaft and a spring, arranged intermediate between the lens housing and the guide, configured to exert a spring force towards the guide.

A method for measuring regions of a tooth in a mouth including: measuring at least one surface point on a surface of the tooth with respect to an element mechanically coupled to said surface point; determining a location of at least one visible reference mechanically coupled to said surface point with respect to said element; estimating a location of said surface point with respect to said visible reference. A device used for such measuring may include a main body comprising a final optical element of an imager which defines an optical field of view directed in a first direction; and a measurement element coupled to said main body extending generally in said first direction; where a tip of said measurement element is sized and shaped to be inserted between a tooth and adjacent gingiva; where said optical field of view is sized to image at least part of a tooth.

A scanner includes a lens assembly comprising a lens having a lens axis and a positioning system to adjust a focal plane of the lens assembly. The positioning system includes an outer element, an inner element coupled to the lens assembly, and a linear-motion bearing that couples the inner element to the outer element.

A method comprises obtaining reference data about a 3D calibration object, the reference data comprising known coordinates for a plurality of points on the object, and obtaining measurement data comprising measurements for the plurality of points on the object, the measurement data having been generated based on scanning of the object by an uncalibrated intraoral scanner. The method comprises comparing the measurement data to the reference data to determine differences therebetween and applying the determined differences between the measurement data and the reference data for the plurality of points to a function to generate a compensation model that compensates for one or more inaccuracies of the intraoral scanner. The compensation model is then stored, wherein the compensation model causes the intraoral scanner to be a calibrated intraoral scanner and is usable to correct measurement errors of the intraoral scanner caused by the one or more inaccuracies of the intraoral scanner.

Embodiments for estimating a surface texture of a tooth are described herein. One method embodiment includes collecting a sequence of images utilizing multiple light conditions using an intra-oral imaging device and estimating the surface texture of the tooth based on the sequence of images.

The present disclosure provides computing device implemented methods, apparatuses, and computing device readable media for confocal imaging using astigmatism. Confocal imaging can include receiving an image of a portion of an object captured by a confocal imaging device having a particular astigmatic character, determining an image pattern associated with the image, and determining a distance between a focus plane of the confocal imaging device and the portion of the object based, at least in part, on information regarding the image pattern. Confocal imaging can also include receiving data representing an image pattern associated with an image of an object captured by a confocal imaging device having a particular astigmatic character and having an image sensor with a plurality of pixels, and determining a positional relationship between the object and a focus plane of the confocal imaging device based on a distribution of the diffraction pattern over a portion of the plurality of pixels.

A scanner for obtaining and/or measuring a 3D geometry of a surface of an object includes a camera having an array of sensor elements, a first device for generating a probe light, a device for transmitting the probe light rays towards the object, a device for transmitting light rays returned from the object to the array of sensor elements, an optical system for imaging with a first depth of field on the camera the transmitted light rays, a device for varying the position of the focus plane on the object, a device for obtaining at least one image from said array of sensor elements, a device for determining the in-focus position(s) of sensor elements, and a device for transforming the in-focus data into 3D coordinates.

An apparatus for dental imaging comprises a light source for generating light, an optics system for focusing the light, and a probe head. The light source, the optics system and the probe head are arranged such that the light passes through the optics system, passes through the probe head, and exits the probe head. The optics system is configured such that, upon entering the probe head, an outermost chief ray of the light with respect to an optical axis of the optics system is divergent to the optical axis and an outermost marginal ray of the light with respect to the optical axis is parallel or divergent to the optical axis.

The present invention relates to an apparatus (28) for varying a focal point (24) of an optical system in a dental 3D-scanner (10), comprising: a lens unit (30) with a lens (20) being movable between a front reversal position and a rear reversal position to vary a position of a focal point with respect to a scan object (22): a guide unit (34) for guiding a movement of the lens unit between the front reversal position and the rear reversal position along a guide axis (48) being parallel to an optical axis (46) of the lens; and a drive unit (36) for driving the movement of the lens unit, said drive unit including a linear motor (38) with an anchor (40) and a stator (42), said anchor being movable along a drive axis (44) of the drive unit that is parallel to the guide axis, said stator being affixed to the guide unit. The present invention further relates to a dental 3D-scanner (10) for scanning a three-dimensional scan object.