Intraoral 3d scanning system using mirror and structured light projection

An intraoral scanning system comprising:

• an elongate handheld wand with a probe at a distal end;
• a structured light projector configured to project a uniform structured light pattern onto an object, the structured light projector comprising a light source configured to transmit light and a pattern generating optical element configured to generate the uniform structured light pattern when the light is transmitted from the light source and through the pattern generating optical element;
• a plurality of cameras configured to capture points of the uniform structured light pattern projected onto the object by the structured light projector;
• a mirror at a distal end of the probe, wherein the structured light projector and a first camera of the plurality of cameras are positioned to face the mirror, and wherein the mirror is positioned to reflect the uniform structured light pattern onto the object and to reflect the uniform structured light pattern from the object into the first camera;
• and
• one or more processors configured to:
• determine a correspondence between projected points in the uniform structured light pattern generated by the structured light projector and captured points of the uniform structured light pattern captured by the plurality of cameras viewing the uniform structured light pattern projected onto the object;
• and
• use the determined correspondence to determine three-dimensional points in space associated with the captured points of the uniform structured light pattern captured by the plurality of cameras viewing the uniform structured light pattern projected onto the object.

A dental scanning system for generating a digital three-dimensional (3D) representation of a dental object, the dental scanning system comprising:

• an intraoral scanning device comprising:
• an elongate handheld wand including a probe at a distal end of the elongate handheld wand;
• one or more light projectors disposed in the probe and configured to project a checkerboard structured light pattern on a surface of the dental object, wherein the checkerboard structured light pattern comprises a plurality of pattern features;
• two or more cameras disposed in the distal end of the probe and configured to acquire one or more sets of images, wherein each set of images comprises at least one image from each camera, wherein each image includes one or more image features of at least a portion of the projected checkerboard structured light pattern;
• a mirror at a distal end of the probe, wherein a light projector of the one or more light projectors and a camera of the two or more cameras are positioned to face the mirror, and wherein the mirror is positioned to reflect the checkerboard structured light pattern onto the dental object and to reflect the checkerboard structured light pattern from the dental object into the camera;
• and
• one or more processors configured to:
• solve a correspondence problem within each set of images such that points in 3D space are determined based on the one or more image features, wherein said points form a solution to the correspondence problem, and wherein the correspondence problem is solved for one or more pattern features of the plurality of pattern features;
• and
• generate the digital 3D representation of the dental object, wherein the solution to the correspondence problem is used to generate the digital 3D representation of the dental object.

An intraoral scanning system comprising:

• an elongate handheld wand with a probe at a distal end;
• one or more structured light projectors configured to project one or more structured light patterns onto an object, the one or more structured light projectors comprising one or more light sources configured to transmit light and a pattern generating optical element configured to generate the one or more structured light patterns when the light is transmitted from the one or more light sources and through the pattern generating optical element, wherein the one or more structured light patterns comprise a first type of pattern points and a second type of pattern points;
• a plurality of cameras configured to capture the first type of pattern points and the second type of pattern points of the one or more structured light patterns;
• a mirror at a distal end of the probe, wherein a structured light projector of the one or more structured light projectors and a camera of the plurality of cameras are positioned to face the mirror, and wherein the mirror is positioned to reflect the one or more structured light patterns onto the object and to reflect the one or more structured light patterns from the object into the camera;
• and
• one or more processors configured to:
• detect the first type of pattern points and the second type of pattern points, wherein the first type of pattern points and the second type of pattern points are resolved;
• and
• process the first type of pattern points and the second type of pattern points to determine three-dimensional points in space for the first type of pattern points and the second type of pattern points.

An intraoral scanning system, comprising:

• an intraoral scanner, comprising:
• an elongate wand with a probe at a distal end of the elongate wand, the probe configured to enter an intraoral cavity of a patient during scanning and defining a longitudinal axis of the intraoral scanner;
• a first structured light projector disposed within the probe and positioned on the longitudinal axis defined by the probe, the first structured light projector comprising a first light source configured to transmit first light and a first pattern generating optical element configured to generate a first uniform structured light pattern when the first light is transmitted from the first light source and through the first pattern generating optical element;
• a second structured light projector disposed within the probe and positioned proximally along the longitudinal axis relative to the first structured light projector, the second structured light projector comprising a second a light source configured to transmit second light and a second pattern generating optical element configured to generate the first uniform structured light pattern or a second uniform structured light pattern when the second light is transmitted from the second light source and through the second pattern generating optical element;
• a first camera disposed within the probe and positioned along the longitudinal axis, the first camera configured to capture points of at least one of the first uniform structured light pattern or the second uniform structured light pattern;
• a second camera disposed within the probe and positioned along the longitudinal axis, the second camera configured to capture the points of at least one of the first uniform structured light pattern or the second uniform structured light pattern;
• a third camera disposed within the probe and positioned on a first side of the longitudinal axis, the third camera configured to capture the points of at least one of the first uniform structured light pattern or the second uniform structured light pattern;
• and
• a fourth camera disposed within the probe and positioned on a second side of the longitudinal axis that is opposite the first side, the fourth camera configured to capture the points of at least one of the first uniform structured light pattern or the second uniform structured light pattern;
• wherein the first camera and the second camera are positioned such that their optical axes are at an angle of 90 degrees or less with respect to each other from a line of sight that is perpendicular to the longitudinal axis;
• and
• wherein the third camera and the fourth camera are positioned such that their optical axes are at an angle of 90 degrees or less with respect to each other.