Intraoral scanner with waveguide pattern projector

Abstract

An intraoral scanner includes an elongated wand including a probe at a distal end of the elongated wand; one or more light sources disposed within the elongated wand distal from the distal end of the probe; one or more waveguides disposed within the probe; and one or more image sensors disposed at the distal end of the probe. The one or more light sources are configured to generate unpatterned light, and the one or more waveguides are configured to receive the unpatterned light generated by the one or more light sources and output patterned light from one or more locations at the distal end of the probe. The one or more image sensors are configured to capture an image of the intraoral object illuminated by the patterned light.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to intraoral scanners using structured light projection, and in particular to intraoral scanners including a waveguide pattern projector. Background Art

[0002] A wide variety of methods and systems have been developed for direct optical measurement of teeth and subsequent automated fabrication for orthodontics and restorations. The term "direct optical measurement" refers to measuring teeth in a patient's mouth. This facilitates the digital construction of a virtual three-dimensional (3D) model of the dental arch, which can be used for computer-aided design (CAD) or computer-aided manufacturing (CAM) of restorations and / or orthodontics, without having to make any cast impressions of the patient's teeth. Such systems typically include an optical probe that is inserted into the patient's mouth, wherein the probe includes means for generating an intraoral scan.

[0003] One type of system that performs intraoral scanning is a system that uses projected light patterns to image a three-dimensional surface. Such systems that use projected light patterns typically include one or more image sensors and one or more pattern projectors disposed at the distal end of the probe (e.g., the end that is inserted into the patient's mouth). However, by including an image sensor and a light projector at the distal end of the probe, the thickness of the probe is increased. This increased thickness may reduce the patient's comfort when the probe is inserted into the patient's mouth. In addition, this increased thickness may reduce the doctor's ability to properly position the probe using an intraoral scanner for optimal scanning acquisition. In addition, intraoral scanners with a camera and a structured light projector in the distal end of the probe may experience heat accumulation at the distal end of the probe. Summary of the invention

[0004] Some example implementations are outlined herein.

[0005] In a first embodiment, an intraoral scanner comprises: an elongated rod including a probe at a distal end of the elongated rod; one or more light sources disposed within the elongated rod away from the distal end of the probe, wherein the one or more light sources are configured to generate unpatterned light; one or more waveguides disposed within the probe, wherein the one or more waveguides are configured to receive the unpatterned light generated by the one or more light sources and output patterned light from one or more locations at the distal end of the probe; and one or more image sensors disposed at the distal end of the probe, wherein the one or more image sensors are configured to capture images of intraoral objects illuminated by the patterned light.

[0006] A second embodiment may extend the first embodiment. In a second embodiment, the one or more waveguides comprise one or more pattern projectors at the distal end of the probe, wherein each pattern projector outputs at least a portion of patterned light.

[0007] A third embodiment may extend the second embodiment. In a third embodiment, each of the one or more pattern projectors comprises a focusing grating coupler.

[0008] The fourth embodiment may extend the third embodiment. In the fourth embodiment, at least one focusing grating coupler is configured to output a light spot pattern.

[0009] The fifth embodiment may expand the fourth embodiment. In the fifth embodiment, the light spot pattern includes four to sixteen light spots with uniform intervals.

[0010] The sixth embodiment can expand any one of the second to fifth embodiments. In the sixth embodiment, each of the one or more waveguides includes: a transmission region having a first width; a pattern projector region including a pattern projector, the pattern projector region having a second width greater than the first width; and a tapered region between the transmission region and the pattern projector region, the tapered region transitioning from the first width to the second width.

[0011] The seventh embodiment may expand any one of the second to sixth embodiments. In the seventh embodiment, the intraoral scanner further includes a microlens array disposed above each of the one or more pattern projectors.

[0012] The eighth embodiment can expand any one of the first to seventh embodiments. In the eighth embodiment, the one or more waveguides include at least one waveguide configured to perform the following: receiving unpatterned light from a light source in one or more light sources; and dividing the unpatterned light into a plurality of paths, wherein each of the plurality of paths includes a different pattern generator configured to output a portion of the patterned light.

[0013] The ninth embodiment may extend the eighth embodiment. In the ninth embodiment, each of the different pattern generators comprises a focusing grating coupler.

[0014] The tenth embodiment can expand any one of the first to ninth embodiments. In the tenth embodiment, the probe includes a longitudinal axis, wherein the one or more image sensors each have an angle of 45 to 135 degrees with the longitudinal axis, and wherein the patterned light is projected from one or more positions at the distal end of the probe at one or more angles of 45 to 135 degrees with the longitudinal axis.

[0015] The 11th embodiment may extend any one of the first to 10th embodiments. In the 11th embodiment, the lateral distance between one or more locations at the distal end of the probe and one or more image sensors in a plane at least partially defined by the longitudinal axis of the probe is less than 2 mm.

[0016] The twelfth embodiment may extend any one of the first to eleventh embodiments. In the twelfth embodiment, the patterned light has approximately constant overlap over the entire focal depth of the intraoral scanner.

[0017] The thirteenth embodiment may extend any one of the first to twelfth embodiments. In the thirteenth embodiment, all light rays output from specific positions among the one or more positions in the patterned light are substantially parallel to each other.

[0018] The 14th embodiment can expand the 13th embodiment. In the 14th embodiment, a first light ray output from a first position among the one or more positions in the patterned light has a first angle relative to a plane at least partially defined by the longitudinal axis of the probe, and wherein a second light ray output from a second position among the one or more positions in the patterned light has a second angle relative to the plane at least partially defined by the longitudinal axis.

[0019] The 15th embodiment can expand any one of the first to 14th embodiments. In the 15th embodiment, the one or more light sources include a first light source that outputs a first coherent light having a first wavelength and a second light source that outputs a second coherent light having a second wavelength, wherein the same waveguide of the one or more waveguides is used to transmit the first coherent light and the second coherent light to one or more locations at the distal end of the probe.

[0020] The 16th embodiment can expand any one of the first to 15th embodiments. In the 16th embodiment, a) the intraoral scanner further includes at least one of a lens, a prism, or a grating that couples the light source of the one or more light sources to the waveguide of the one or more waveguides, or b) the light source is directly coupled to the waveguide.

[0021] The seventeenth embodiment may expand any one of the first to sixteenth embodiments. In the seventeenth embodiment, the one or more waveguides include a first plurality of waveguides, and the one or more light sources include a plurality of semiconductor lasers.

[0022] The eighteenth embodiment may expand any one of the first to seventeenth embodiments. In the eighteenth embodiment, the intraoral scanner further comprises: a refractive coating on at least one surface of the one or more waveguides at one or more locations.

[0023] The 19th embodiment can expand any one of the first to 18th embodiments. In the 19th embodiment, the intraoral scanner further includes: a first plate in the probe, wherein the first plate covers at least a first subset of the one or more image sensors, so that return light from the imaged intraoral object passes through the first plate to the first subset of the one or more image sensors, wherein the first plate includes at least a first subset of the one or more waveguides.

[0024] The 20th embodiment can expand the 19th embodiment. In the 20th embodiment, the intraoral scanner further includes: a second plate in the probe, disposed on the first plate so that the second plate also covers at least the first subset of the one or more image sensors, wherein the second plate includes at least a second subset of the one or more waveguides, wherein the first subset of the one or more waveguides outputs patterned light from the first subset of the one or more locations, and wherein the second subset of the one or more waveguides outputs patterned light from the second subset of the one or more locations, the second subset not overlapping the first subset of the one or more locations.

[0025] The 21st embodiment can expand the 19th embodiment. In the 21st embodiment, the first plate has a first orientation relative to a plane defined at least in part by the longitudinal axis of the probe, and the intraoral scanner further includes: a second plate in the probe, wherein the second plate covers at least a second subset of the one or more image sensors so that return light from the imaged intraoral object passes through the second plate to the second subset of the one or more image sensors, wherein the second plate includes at least a second subset of the one or more waveguides, and wherein the second plate has a second orientation relative to the plane defined at least in part by the longitudinal axis of the probe.

[0026] In the 22nd embodiment, the intraoral scanner includes: a slender rod including a probe at the distal end of the slender rod; one or more light sources disposed in the slender rod, wherein the one or more light sources are configured to generate unpatterned light, and wherein the one or more light sources are oriented to project the unpatterned light in a first direction along the length of the slender rod; and one or more pattern generating optical elements disposed in the probe, wherein the one or more pattern generating optical elements are configured to receive the unpatterned light generated by the one or more light sources and output patterned light from one or more positions of the probe.

[0027] The 23rd embodiment may extend the 22nd embodiment. In the 23rd embodiment, the one or more pattern generating optical elements include one or more waveguides.

[0028] The 24th embodiment may extend the 23rd embodiment. In the 24th embodiment, each of the one or more waveguides includes one or more focusing grating couplers that generate patterned light at one or more locations.

[0029] The 25th embodiment may expand on the 22nd to 24th embodiments. In the 25th embodiment, the one or more locations are located at the distal end of the probe.

[0030] The 26th embodiment can expand on the 22nd to 25th embodiments. In the 26th embodiment, the one or more light sources are positioned away from the distal end of the probe, and the one or more pattern generating optical elements output patterned light in a second direction angled to the first direction and in the field of view of the one or more cameras of the intraoral scanner.

[0031] The 27th embodiment may expand on the 22nd to 26th embodiments. In the 27th embodiment, the one or more pattern generating optical elements include a reflector for redirecting unpatterned light from a first direction to a second direction.

[0032] In the 28th embodiment, the intraoral scanner includes: one or more lasers, which are arranged in the intraoral scanner away from the distal end of the intraoral scanner, wherein the one or more lasers are configured to generate a first unpatterned light having a first wavelength; one or more waveguides, which are arranged in the probe, wherein the one or more waveguides each include a transmission region, which is configured to receive the first unpatterned light and transmit the unpatterned light to a projection region including a focusing grating coupler, wherein the focusing grating coupler is used to output the patterned light onto an object outside the intraoral scanner; and one or more image sensors, which are arranged at the distal end of the intraoral scanner, wherein the one or more image sensors are configured to capture an image of the intraoral object illuminated by the patterned light. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the disclosure are illustrated by way of example and not limitation in the figures of the accompanying drawings.

[0034] Figure 1 An intraoral scanner according to an embodiment is shown having an image sensor disposed at a distal end of the intraoral scanner and one or more light sources disposed away from the distal end of the intraoral scanner.

[0035] Figure 2A A probe of an intraoral scanner according to an embodiment is shown and a first projection field of patterned light output by the intraoral scanner is shown.

[0036] Figure 2BA probe of an intraoral scanner according to an embodiment is shown and a second projection field of patterned light output by the intraoral scanner is shown.

[0037] Figure 3A A first waveguide configuration for use in an intraoral scanner is shown according to an embodiment.

[0038] Figure 3B A second waveguide configuration for use in an intraoral scanner according to an embodiment is shown.

[0039] Figure 3C A third waveguide configuration for use in an intraoral scanner is shown according to an embodiment.

[0040] Figure 4A An example layout of a camera, waveguide, and light source in an intraoral scanner according to an embodiment is shown.

[0041] Figure 4B An example layout of a group of cameras and a group of waveguides in an intraoral scanner according to an embodiment is shown.

[0042] Figure 4C is a diagram depicting a number of different configurations for the location of a camera in a probe of an intraoral scanner according to some embodiments of the present disclosure.

[0043] Figure 5A A perspective view of an example waveguide including a focusing grating coupler coupled to a laser via a coupling is shown in accordance with an embodiment.

[0044] Figure 5B A perspective view of an example waveguide including a focusing grating coupler directly coupled to a laser is shown in accordance with an embodiment.

[0045] Figure 6 A top view of a focusing grating coupler for use in a waveguide is shown according to an embodiment.

[0046] Fig. 7A A perspective view of an example waveguide including a focusing grating coupler configured to output patterned light having a first focused spot pattern is shown in accordance with an embodiment.

[0047] Figure 7B A perspective view of an example waveguide including a focusing grating coupler configured to output patterned light having a second focused spot pattern is shown in accordance with an embodiment.

[0048] Figure 7C An FGC region is shown divided into a 10×10 square grid according to one embodiment.

[0049] Figure 8A top view of a focusing grating coupler design showing an output spot pattern according to an embodiment.

[0050] Fig. 9 A perspective view of an example waveguide including a focusing grating coupler configured to output patterned light having a focused spot pattern and a microlens array above the focusing grating coupler is shown according to an embodiment.

[0051] Figure 10A-10B A view of a focusing grating coupler according to an embodiment is shown, which shows how the focusing grating coupler is designed for use in an intraoral scanner. DETAILED DESCRIPTION

[0052] Embodiments of intraoral scanners are described herein that use structured light (also known as patterned light) projection to determine depth information of an imaged object (e.g., an imaged intraoral object in a patient's mouth). There are multiple intraoral scanners that use the principles of structured light projection to generate three-dimensional (3D) scans of intraoral objects. An example of such an intraoral scanner using structured light projection is described in the following document: U.S. Patent Publication No. 2019 / 0388193, entitled "Intraoral 3DScanner Employing Multiple Miniature Cameras and Multiple Miniature PatternProjectors," filed on June 19, 2019, which is incorporated herein by reference in its entirety. Another example of such an intraoral scanner using structured light projection is described in the following document: U.S. Patent Publication No. 2020 / 0404243, also entitled “Intraoral 3DScanner Employing Multiple Miniature Cameras and Multiple Miniature Pattern Projectors”, filed on June 23, 2020, which is incorporated herein by reference in its entirety. Such existing intraoral scanners using structured light projection generally rely on structured light projectors that are disposed at the distal end of a probe of the intraoral scanner inserted into the patient's mouth. Such structured light projectors have a minimum size, which imposes a constraint on the minimum thickness of the probe of the intraoral scanner.

[0053] It is generally desirable that the probe of an intraoral scanner be as thin as possible. A thinner intraoral scanner probe is easier to insert into a patient's mouth, thereby causing less discomfort to the patient. In addition, a thinner intraoral scanner probe has more room for maneuvering within the oral cavity due to its reduced thickness. However, the size of the structured light projector disposed in the distal end of the intraoral scanner probe causes these probes to be relatively thick. Therefore, conventional intraoral scanners using structured light projection have historically had a minimum probe thickness necessary to accommodate the size of the structured light projector.

[0054] In addition, components such as the structured light projector and camera in the distal end of the intraoral scanner probe all generate a certain amount of heat. Having all of these components in the distal end of the probe can result in heat buildup in the distal end of the probe. Therefore, one or more cooling technologies may be required to mediate this heat buildup. Therefore, the structured light projector may require a heat flow system, electrical contacts, etc., which may result in an increased thickness of the intraoral scanner probe.

[0055] In an embodiment, one or more light sources are disposed away from the distal end of the probe. One or more light sources may be oriented to direct light in a first direction along the length of the elongated rod comprising the probe (e.g., approximately along the longitudinal axis of the elongated rod). The light emitted by the one or more light sources may be unpatterned light, which may be directed to the proximal end of the probe generally along the longitudinal axis of the elongated rod, where the light may enter a pattern generating optical element, which may output patterned light. The patterned light may be output in a second direction at an angle to the first direction and may be in the field of view of one or more cameras of the intraoral scanner. In some embodiments, the pattern generating optical element includes a reflector such as a mirror or a prism that redirects the light from the first direction to the second direction. In some embodiments, one or more light sources are coupled to a waveguide that transmits the generated light to the distal end of the probe. Alternatively, light may be emitted toward the distal end of the probe without using a waveguide. The waveguide may be a sheet of material transparent to the wavelength of light used. Examples of materials for waveguides include doped glass, silicon, doped SiO2, GaAs, AsInP, Si3N4 (silicon nitride), or silicon dioxide. The light source can be configured to generate unstructured or unpatterned light, and the waveguide can have a patterned area (also referred to as a pattern projector) that emits patterned light or structured light. In some embodiments, the waveguide or the patterned area of ​​the waveguide can be referred to as a pattern generating optical element. The patterned area can be a pattern projector, which has a significantly smaller footprint than a conventional structured light projector. The use of a waveguide with a pattern projector for generating patterned light reduces the size (e.g., thickness and / or width) of the probe and allows additional degrees of freedom in the spatial design of the intraoral scanner. In an embodiment, the patterned area includes a focusing grating coupler (FGC), which outputs patterned light with a preconfigured pattern. Since the light source is not disposed in the probe at the distal end of the probe, the probe (or at least the distal end of the probe) can be significantly thinner than what has been achievable to date. In addition, the heat accumulation at the distal end of the probe can be reduced by arranging the light source away from the distal end of the probe.

[0056] In some embodiments, the patterned regions of one or more waveguides can be configured to generate unpatterned light, such as focused light. The embodiments are discussed with respect to waveguides having patterned regions that generate patterned light. However, it should be understood that all such embodiments discussed herein may alternatively or additionally include waveguides having patterned regions that generate unpatterned light. In addition, it should be understood that the embodiments also encompass the use of pattern generating optical elements that do not include waveguides or focusing grating couplers. For example, the pattern generating optical element may include a reflector (e.g., a mirror or prism) that redirects light from a first direction to a second direction and a diffractive optical element (DOE) that receives light having a second direction and outputs patterned light.

[0057] Reference now Figure 1 , which is a schematic diagram of an intraoral scanner 100 according to some applications of the present disclosure, the intraoral scanner including an elongated wand (e.g., a body having a probe 108 at one end of the body), such as an elongated handheld wand. The intraoral scanner 100 can be a wireless scanner including a wireless module (not shown) disposed in the body of the intraoral scanner 100 for wirelessly connecting to a computing device. Alternatively, the intraoral scanner 100 can be a wired scanner that is connected to the computing device via a wired connection. Alternatively, the intraoral scanner 100 can be configured to operate in a wired mode or a wireless mode, depending on the circumstances.

[0058] The intraoral scanner 100 includes one or more light sources 154 that are optically coupled to one or more waveguides in one or more substrates 150 (e.g., directly or via an optical coupler 152 such as a lens, prism, and / or grating). In one embodiment, the (one or more) light sources 154 are optically coupled to the one or more waveguides directly (e.g., through a direct connection between a laser die or an optical fiber and the edge of the waveguide). In some embodiments, the edge of the waveguide may be tapered (e.g., the horizontal width of the waveguide may decrease toward the edge). The tapered edge of the waveguide may provide edge coupling between the waveguide and the one or more light sources 150. In one embodiment, the optical coupler 152 is a grating constructed on top of the waveguide or etched into the waveguide. As shown, in some embodiments, the (one or more) light sources 154 are not disposed at the distal end of the probe (i.e., disposed away from the distal end of the probe). The light source(s) 154 can be disposed, for example, near the center of the intraoral scanner 100, at the proximal end of the intraoral scanner 100, at the proximal end of the probe 108, or at another location within the intraoral scanner 100 away from the distal end of the intraoral scanner 100. As shown, the light source(s) 154 can be positioned and oriented to output light in a direction parallel to the longitudinal axis of the intraoral scanner 100 (e.g., along the longitudinal axis of the intraoral scanner 100). Figure 1 The light is roughly aligned with the Y-axis in the image.

[0059] In some embodiments, one or more light sources 154 are disposed at or near the distal end of the probe 108, but have an orientation that is generally parallel to the longitudinal axis of the intraoral scanner 100 (or parallel to the probe 108 of the intraoral scanner, such as in the case where the probe has a longitudinal axis that is different from the longitudinal axis of the rest of the elongated handheld wand). By orienting the light sources 154 so that the light sources 154 project light generally parallel to the longitudinal axis of the intraoral scanner probe 108 (e.g., along the Y axis) and / or or orienting the light sources 154 away from the distal end of the probe 108, the thickness (H1) of the probe 108 can be minimized.

[0060] In an embodiment, one or more light sources 154 are lasers (e.g., integrated semiconductor laser projectors) configured to output coherent light of one or more wavelengths. For example, the light source 154 may include one or more first light sources that output light having a first wavelength (e.g., blue light) and one or more second light sources that output light having a second wavelength (e.g., green light). The light output by the light source 154 may be unpatterned light. Therefore, the light entering the waveguide in the substrate 150 may be unpatterned light. However, in an embodiment, the light exiting the waveguide in the substrate 150 is patterned light.

[0061] One or more waveguides are formed in a thin substrate 150 (e.g., a sheet / plate of glass or silicon dioxide) having one or more doped or deposited regions that form waveguides and transmit light from (one or more) light sources 154. In one embodiment, (one or more) waveguides are formed in a substrate 150 (such as a fused silica substrate, a glass substrate, a plastic substrate, etc.) that includes one or more regions having an increased refractive index compared to surrounding regions of the substrate. The region with an increased refractive index can be achieved by introducing one or more additional materials (e.g., by creating a doped region by doping the substrate with molecules of another material, by depositing another material on top of or within the substrate at the region (e.g., via chemical vapor deposition (CVD)), etc.). One or more regions can be channels (also referred to as transmission regions) within (one or more) substrates 150 that have dopants or other additional molecules that increase the refractive index at the region. In some embodiments, the waveguide can have a width (i.e., lateral width) of about 1-5 microns. In some embodiments, the waveguide can have a lateral width that is the width of the substrate. In this case, the waveguides may not be channels, but may instead be thin films, and the light may be confined only in the z-axis. Thus, the light may diverge in the x-axis (e.g., similar to light in free space) while propagating in the y-axis. In such embodiments, the tapered sections (discussed below) may be omitted. In embodiments, the channels of the waveguide(s) may have a depth in the substrate of about 1-5 microns. In embodiments, the sheet / plate including the waveguide(s) has a thickness of about 0.5-2 mm (e.g., about 1 mm).

[0062] In one embodiment, as shown, the substrate (or substrates) 150 including the waveguide(s) is positioned on the probe such that the substrate is between the camera 104 and the object 112 being imaged. Thus, light reflected from the object 112 can pass through the substrate(s) 150 including the waveguide(s) to reach the camera 104. Alternatively, the substrate 150 including the waveguide(s) can be in the same plane as the camera 104. In such an embodiment, the substrate can include a cutout for the camera 104. In another embodiment, the substrate 150 including the waveguide(s) is positioned behind the camera. In such an embodiment, light does not pass through the substrate to reach the camera. In one embodiment, the substrate(s) 150 including the waveguide(s) forms a window for the intraoral scanner 100.

[0063] The waveguide(s) may each include one or more pattern projectors 102 (also referred to as projection areas) configured to emit patterned or structured light from the waveguide(s) at one or more locations at (or near) the distal end of the probe 108. In an embodiment, each of the one or more pattern projectors 102 is a focusing grating coupler (FGC) that has been configured to output a specific pattern of light (or unpatterned light in some cases). The FGC may include an array of grooves, lines, and / or other features etched into the waveguide and / or otherwise formed in, on, or under the waveguide (e.g., in a doped silica plate). The grooves / lines / features may be curved and chirped so that their average period is the size of the wavelength of light to be emitted into the waveguide. The grooves / lines / features may be formed using conventional manufacturing methods, such as using electron beam lithography, doping, deposition, and / or nanoimprinting. For example, a photoresist may be formed on a substrate, which may then be patterned and selectively cured using photolithography or nanoimprinting. The cured or uncured portions of the photoresist may then be removed. Exposed areas of the substrate not covered by the photoresist may be etched, and the remaining portions of the photoresist may then be removed after etching. In some embodiments, the FGC includes an array of doped regions in the substrate having a refractive index different from that of the waveguide (e.g., the refractive index of the tapered region or the transmission region of the waveguide). Any of the FGCs described in the embodiments (e.g., Figure 3A-3C and Figure 5- Fig. 10B) may include an array of grooves, an array of deposited features / lines, or an array of regions having an increased or decreased refractive index (e.g., formed by doping) compared to the rest of the waveguide. In some embodiments, the array of grooves, lines, features, and / or doped regions (e.g., having an increased or decreased refractive index) may be fabricated on the top of the waveguide (e.g., on the top of the projected area of ​​the waveguide), on the bottom of the waveguide (e.g., at the interface of the waveguide with an undoped portion of the substrate containing the waveguide), or on both the top and bottom of the waveguide.

[0064] As shown, light traveling through the pattern projector 102 (e.g., through the FGC) is emitted from the pattern projector 102 at an angle to the longitudinal axis (e.g., approximately along the z-axis that is orthogonal to the longitudinal axis). The emitted patterned light can be output at an angle of about, for example, 45 degrees to 135 degrees to the longitudinal axis (e.g., to the y-axis), and thus can be projected from one or more locations of the pattern projector 102 at the distal end of the probe 108 at one or more angles of 45 degrees to 135 degrees to the longitudinal axis. Additionally or alternatively, the emitted patterned light can have a Figure 1 The x-axis shown in is at an angle of about 45 degrees to about 135 degrees. Different pattern projectors 102 can be configured to emit light at different angles. Therefore, the first light output from the first position in the patterned light can have a first angle relative to a plane defined at least in part by the longitudinal axis of the probe, and the second light output from the second position in the patterned light can have a second angle relative to a plane defined at least in part by the longitudinal axis. In an embodiment, the pattern projector 102 can be configured to radiate any target beam shape. Examples of such beam shapes include spot patterns (e.g., four to sixteen spots, twelve spots, nine spots, etc.), line patterns, grid patterns, checkerboard patterns, etc.

[0065] The use of a waveguide with an integrated pattern projector (e.g., FGC) enables minimization of the height (i.e., thickness) H1 of the probe 28. In some applications, the height H1 of the probe 108 is less than 15 mm, or less than 10 mm, or less than 8 mm, or less than 6 mm, wherein the height H1 of the probe 108 is measured from a lower surface (sensing surface) 180 to an upper surface 182 opposite the lower surface 180 through which reflected light from the scanned object 112 enters the probe 108. In some applications, the height H1 is between 4-10 mm.

[0066] In some embodiments, the light beams output by a particular pattern projector 102 are substantially parallel to each other. Thus, the light pattern can remain focused within a wide focus range of the intraoral scanner 100 (e.g., within a few millimeters). In contrast to designs where the patterned light projector is disposed at the distal end of the probe and directed toward the object 112, the use of a pattern projector 102 (e.g., FGC) in or at a window of the probe enables a wider design latitude in terms of the projection angle and projection field of the projected pattern. For example, because the use of the pattern projectors 102 described herein can greatly increase the number of locations where patterned light is emitted, the illumination field α (alpha) of each pattern projector 102 can be less than 70 degrees.

[0067] In an embodiment, the patterned light output by the pattern projector 102 is a two-dimensional (2D) fan of a focused beam (eg, which may form a pattern of projected spots over the focal range of the intraoral scanner 100).

[0068] Many waveguides and / or pattern projectors 102 may be used in the intraoral scanner 100 to design any desired light pattern. The waveguides and integrated pattern projectors 102 are very small, and so many of them may fit into the head of a single probe (e.g., the distal end of the probe 108).

[0069] In an embodiment, the probe may include a first waveguide configured to transmit light having a first wavelength and a second waveguide configured to transmit light having a second wavelength. In an embodiment, light of different wavelengths may be output by the same waveguide (e.g., a pattern projector 102 of a waveguide in substrate 150). Light of different wavelengths output by the same FGC may have different patterns, angles, focusing characteristics, etc. In an embodiment, light of different wavelengths is output serially (e.g., one after another) by the same waveguide and pattern projector. Alternatively, light of multiple wavelengths may be output in parallel (e.g., simultaneously) by the same waveguide and pattern projector.

[0070] In an embodiment, using a waveguide with an integrated pattern projector 102 and a light source 154 distal to the probe 108 enables the radiation system of the intraoral scanner 100 to be integrated into a single silica window with a width of about 12 mm down to about 1 mm.

[0071] In some embodiments, a first plate including a first set of waveguides is disposed in a distal end of the probe 108, wherein the first plate covers at least a first subset of one or more image sensors such that return light from an imaged intraoral object passes through the first plate to the first subset of one or more image sensors. In some embodiments, a second plate is disposed in the probe on the first plate such that the second plate also covers at least the first subset of one or more image sensors, wherein the second plate includes a second set of waveguides. The first set of waveguides outputs patterned light from a first set of one or more locations, and the second set of waveguides outputs patterned light from a second set of one or more locations, the second set not overlapping the first subset of one or more locations. In some embodiments, the second plate in the probe is disposed on the first plate such that the second plate also covers at least the first set of one or more image sensors, wherein the second plate includes a second set of waveguides, wherein the first set of waveguides outputs patterned light from a first subset of one or more locations, and wherein the second set of waveguides outputs patterned light from a second set of one or more locations, the second set not overlapping the first subset of one or more locations.

[0072] In some embodiments, the first plate has a first orientation relative to a plane defined at least in part by a longitudinal axis of the probe 108. The probe 108 also includes a second plate in the probe that covers at least a second subset of the one or more image sensors, such that return light from the imaged intraoral object passes through the second plate to the second subset of the one or more image sensors. The second plate includes a second set of waveguides, and the second plate has a second orientation relative to a plane defined at least in part by the longitudinal axis of the probe, which can be different from the first orientation.

[0073] In an embodiment, a plurality of cameras 104 are disposed at or near a distal end of a probe 108. The cameras 104 may be coupled to a rigid structure 106 disposed within the probe 108 at a distal end 110 of the body of the intraoral scanner 100. In some applications, the probe 108 is inserted into the oral cavity of a subject or patient during an intraoral scanning procedure.

[0074] For some applications, the pattern projector 102 of the waveguide in the substrate 150 is configured such that patterned light emitted by the pattern projector 102 is projected onto an object 112 placed in the illumination field of the pattern projector outside the intraoral scanner 100. The cameras 104 can be positioned within the probe 108 such that each camera 104 faces an object 112 placed in the camera's field of view outside the intraoral scanner 100. Alternatively, one or more image sensors can be positioned in the proximal end of the intraoral scanner and can observe the object 112 by reflecting light from a reflector and into the image sensor. The positioning and configuration of the pattern projector 102 and the camera 104 within the probe 108 as described herein enables the intraoral scanner 100 to have an overall large field of view while maintaining a low profile (e.g., a small thickness H1).

[0075] In some applications, each camera 104 has a large field of view β (beta) of at least 45 degrees (e.g., at least 70 degrees, such as at least 80 degrees, such as 85 degrees). In some applications, the field of view can be less than 120 degrees, such as less than 100 degrees, such as less than 90 degrees. In one embodiment, the field of view β (beta) of each image sensor is between 80 degrees and 90 degrees, which may be particularly useful because it provides a good balance between pixel size, field of view and camera overlap, optical quality and cost. The camera 104 may include an image sensor 118 and an objective optical system (objective optics) 120 including one or more lenses. In order to achieve close-range focused imaging, the camera 104 can focus at an objective focal plane 122 between 1 mm and 30 mm, such as between 4 mm and 24 mm, such as between 5 mm and 11 mm, such as 9 mm-10 mm from the lens farthest from the sensor. In some applications, the camera 104 can capture images at a frame rate of at least 30 frames per second (e.g., a frame rate of at least 75 frames per second, such as a frame rate of at least 100 frames per second). In some applications, the frame rate may be less than 200 frames per second.

[0076] The large field of view achieved by combining the individual fields of view of all cameras can improve accuracy by reducing the amount of image stitching error, especially in edentulous areas where the imaged gingival surface is smooth and fewer clear high-resolution 3D features may be present. Having a larger field of view enables large smooth features (such as the overall curve of a tooth) to appear in each image frame, which improves the accuracy of stitching the individual surfaces obtained from multiple such image frames.

[0077] For some applications, to improve image capture, each camera 104 has a plurality of discrete preset focus positions, at each focus position, the camera focuses at a corresponding object focal plane 122. Each camera 104 may include an autofocus actuator that selects a focus position from the discrete preset focus positions to improve a given image capture. Additionally or alternatively, each camera 104 includes an optical aperture phase mask that extends the depth of focus of the camera so that the image formed by each camera remains in focus at all object distances between 1 mm and 30 mm, such as between 4 mm and 24 mm, such as between 5 mm and 11 mm, such as 9 mm-10 mm, from the lens farthest from the sensor.

[0078] In some applications, the cameras 104 and pattern projectors 102 (e.g., FGCs) are arranged in a probe 108 in a closely packed and / or alternating manner such that (a) a majority of the field of view of each camera overlaps with the field of view of an adjacent camera, and (b) a majority of the field of view of each camera overlaps with the illumination fields of view of multiple surrounding pattern projectors. Optionally, at least 20%, such as at least 50%, such as at least 75%, of the projected light pattern is in the field of view of at least one camera at an object focal plane 122, which is located at least 4 mm from the lens farthest from the sensor. Due to the different possible configurations of the pattern projectors and cameras, some projected patterns may never appear in the field of view of any camera, and some projected patterns may be obscured from view by the object 112 when the scanner moves around during scanning.

[0079] The rigid structure 106 may be a non-flexible structure to which the cameras 104 are coupled to provide structural stability for the optics within the probe 108. In an embodiment, the substrate(s) 150 including the waveguides may also be coupled to the rigid structure 106 and / or the cameras 104. Coupling all of the cameras (and optionally the substrate 150) to a common rigid structure helps maintain the geometric integrity of the optics of each pattern projector 102 and each camera 104 under varying environmental conditions (e.g., under mechanical stresses that may be caused by a subject's mouth). In addition, the rigid structure 106 helps maintain stable structural integrity and positioning of the pattern projectors 102 and cameras 104 relative to each other.

[0080] For some applications, there is at least one uniform light projector 128 (which can be a non-structured light projector that projects incoherent (e.g., broadband) light within a certain wavelength range) coupled to the rigid structure 106. The uniform light projector 128 can transmit white light onto the scanned object 112. At least one camera (e.g., one of the cameras 104) captures a two-dimensional color image of the object 112 using illumination from the uniform light projector 128. Light reflected from the object 112 can enter the scanner head and be received by the camera. The camera can then generate intraoral scan data based on the received light. In an embodiment, one or more near infrared (near IR) light projectors and / or ultraviolet (UV) unpatterned light projectors can also be included in the probe 108.

[0081] The scan data generated by the intraoral scanner 100 can be sent (e.g., via a wired or wireless connection) to a processor or processing device 130 of a computing device that can be external to the intraoral scanner 100. The processor 130 can run a surface reconstruction algorithm that can generate a 3D surface of the object 112 using the detected pattern (e.g., a dot pattern) projected onto the object 112. In some embodiments, the processor 130 can combine at least one 3D scan captured using illumination from the structured light projector 102 with a plurality of intraoral 2D images captured using illumination from the uniform light projector 128 to generate a digital three-dimensional image of the intraoral three-dimensional surface. Using a combination of structured light and uniform illumination enhances the overall capture of the intraoral scanner and can help reduce the number of options that the processor 130 needs to consider when running a corresponding algorithm for detecting depth values ​​of the object 112. In one embodiment, an intraoral scanner and corresponding algorithm described in the following document are used: U.S. Application No. 16 / 446,181 filed on June 19, 2019. U.S. Application No. 16 / 446,181, filed on June 19, 2019, is incorporated herein by reference in its entirety.

[0082] For some applications, all data points acquired at a particular time are used as a rigid point cloud, and multiple such point clouds are captured at a frame rate of more than 10 captures per second. The multiple point clouds are then stitched together using a registration algorithm (e.g., iterative closest point (ICP)) to produce a dense point cloud. A surface reconstruction algorithm can then be used to generate a representation of the surface of object 112.

[0083] For some applications, at least one temperature sensor 132 is coupled to the rigid structure 106 and measures the temperature of the rigid structure 106. A temperature control circuit 134 disposed within the intraoral scanner 100 (a) receives data indicating the temperature of the rigid structure 106 from the temperature sensor 132, and (b) activates a temperature control unit 136 in response to the received data. The temperature control unit 136 (e.g., a PID controller) can maintain the probe 108 at a target temperature (e.g., between 35 and 43 degrees Celsius, between 37 and 41 degrees Celsius, etc.). Maintaining the probe 108 above 35 degrees Celsius (e.g., above 37 degrees Celsius) reduces fogging of the glass surface of the intraoral scanner 100 through which the structured light projector 102 projects and through which the camera 104 views when the probe 108 enters the oral cavity, which is typically about or above 37 degrees Celsius. Maintaining the probe 108 below 43 degrees (e.g., below 41 degrees Celsius) can prevent discomfort or pain.

[0084] In some embodiments, heat can be exhausted from the probe 108 by a heat conductive element 140 (e.g., a heat pipe) disposed within the intraoral scanner 100, such that the distal end 145 of the heat conductive element 140 contacts the rigid structure 106 and the proximal end 151 contacts the proximal end 160 of the intraoral scanner 100. Heat is thereby transferred from the rigid structure 106 to the proximal end 160 of the intraoral scanner 100. Alternatively or additionally, a fan disposed in the handle region of the intraoral scanner 100 can be used to exhaust heat from the probe 108.

[0085] In some embodiments, the proximal end 160 of the intraoral scanner 100 includes a handle of the intraoral scanner. In some embodiments, the proximal end 160 of the intraoral scanner 100 includes at least one of the one or more light sources 154. In an example, the one or more light sources 154 may not be disposed in the probe 108. Alternatively, at least one of the one or more light sources 154 is disposed in the probe 108.

[0086] Figure 2A 2 shows a probe 205 of an intraoral scanner 200 according to an embodiment, and shows a first projection field 215 of patterned light output by the intraoral scanner 200. In an embodiment, the intraoral scanner 200 corresponds to Figure 1Intraoral scanner 100. As shown, probe 205 includes a window 210 at the distal end of the probe. In some embodiments, the window includes one or more waveguides formed therein. The waveguide may include a pattern projector (e.g., FGC), which may be etched or otherwise formed into the surface of window 210. Window 210 may be formed of a material transparent to light. Examples of materials that may be used for window 210 include silicon dioxide, glass, quartz, plastic, polycarbonate, doped glass, silicon, doped silicon, GaAs, AsInP, etc. Some materials such as glass, doped glass, polycarbonate, quartz, and plastic may be transparent to visible light and may be used for wavelengths of visible light (e.g., blue and green coherent light output by a laser). Some materials such as silicon, doped silicon, GaAs, and AsInP may be transparent to wavelengths outside the visible region and may be used for, for example, IR or near-IR radiation. In some embodiments, window 210 is disposed above one or more waveguides, and thus the waveguide may not be integrated into window 210 in such an embodiment. In some embodiments, the window 210 includes two windows, wherein the first window includes a waveguide and the second window does not have a waveguide. The second window can be placed above the first window, for example to provide protection, anti-reflection, a refractive index matching with the external environment (e.g., air), etc. In order to generate a spot array or other light pattern with a first projection field 215, the intraoral scanner 200 may include identical pattern projectors (e.g., FGCs) uniformly distributed within the window 210. In one embodiment, the pattern projectors all have the same orientation relative to the longitudinal axis of the probe 205. For example, each of the pattern projectors can be aligned with the longitudinal axis of the probe 205. In one embodiment, the focused light that forms the spot array or other pattern has approximately parallel rays (e.g., so that the projection field remains approximately constant over the focal depth range of the intraoral scanner).

[0087] Figure 2B The probe 255 of the intraoral scanner 250 according to an embodiment is shown, and a second projection field 265 of patterned light output by the intraoral scanner 250 is shown. In an embodiment, the intraoral scanner 250 corresponds to Figure 1Intraoral scanner 100. As shown, probe 255 includes a window 260 at the distal end of the probe. In some embodiments, window 260 includes one or more waveguides formed therein. The waveguide may include a pattern projector (e.g., FGC), which may be etched or otherwise formed into the surface of window 260. Window 260 may be formed of a material transparent to light, as described above. In some embodiments, window 260 is disposed above one or more waveguides, and thus the waveguide may not be integrated into window 260 in such an embodiment. In order to generate an array of spots or other patterns with a second projection field 265, intraoral scanner 250 may include the same pattern projector (e.g., FGC) distributed within window 260. In one embodiment, the pattern projectors have different orientations relative to the longitudinal axis of probe 265. For example, a first subset of pattern projectors may have a first angle relative to the longitudinal axis, and a second subset of pattern projectors may have a second angle relative to the longitudinal axis. In one embodiment, second projection field 265 is considered to be a wide projection field (compared to first projection field 215). In an embodiment, different FGCs may have the same orientation relative to each other, but radiate at different angles relative to each other. Additionally or alternatively, the FGCs may have different orientations relative to each other.

[0088] Figure 3A A first waveguide configuration 300 for use in an intraoral scanner according to an embodiment is shown. In one embodiment, the first waveguide configuration 300 is used Figure 2A For example, the first waveguide configuration 300 can be integrated into the intraoral scanner 200. Figure 2A In an embodiment, the first waveguide configuration 300 generates a first projection field 215.

[0089] The first waveguide configuration 300 includes one or more first waveguides 308A and one or more second waveguides 308B integrated into a transparent substrate (e.g., fused silica) 312. In one embodiment, the transparent substrate has a width of about 2 mm. Other widths are also easily achievable. Each of the waveguides 308A-B includes a transmission region 310A-B, a tapered region 315A-B, and a projection region (pattern projector) 320A-B. The transmission region 310A-B can be significantly longer and thinner than the other regions. The projection region 320A-B can have a width and length based on the pattern to be projected by the projection region 320A-B and / or based on the target depth of field configuration. The projection region 320A-B can be significantly wider and shorter than the transmission region 310A-B. The tapered region 315A-B can transition the width of the waveguide 308A-B between the first width of the transmission region 310A-B and the second width of the projection region 320A-B. In one embodiment, the FGC is configured to receive blue light and / or green light (e.g., light having a wavelength of about 520 nm and / or light having a wavelength of about 450 nm). In an embodiment, for light having a wavelength of 520 nm, the FGC may have grooves having a period of about 315 nm. In an embodiment, for light having a wavelength of about 450 nm, the FGC may have grooves having a period of about 270 nm. The length of the FGC may be based at least in part on depth of field considerations and may be, for example, hundreds of microns (e.g., about 150 microns). In one embodiment, the transmission regions 310A-B have a width and depth of about 3-5 microns, and the FGC has grooves having a depth of about 100 nm.

[0090] As shown, waveguide 308A can be configured to receive and propagate a first coherent light 305A having a first wavelength, and waveguide 308B can be configured to receive and propagate a second coherent light 305B having a second wavelength. In addition, light of two or more wavelengths can be propagated through the same waveguide. Additionally or alternatively, a single source with a wide radiation spectrum can be coupled to the waveguide and propagate a wavelength spectrum through the waveguide. In some embodiments, a separate light source inputs light into each waveguide 310A, and a single light source inputs light into a single waveguide 310B, which divides the light into a plurality of (e.g., three) sub-waveguides. Each light source can be optically connected to a waveguide having a single pattern projector 320A-B, or to a waveguide that is divided into a plurality of sub-waveguides and includes a plurality of pattern projectors 320A-B. In the first waveguide configuration 300, waveguides 308A-B are substantially aligned with the longitudinal axis of substrate 312 (and a probe including substrate 312), which can correspond to the Y axis. Furthermore, each of the projected regions 320A-B (eg, FGCs) share the same orientation aligned with the longitudinal axis of the substrate 312. In some embodiments, the transmission region of the waveguide is curved in one or more directions (eg, not necessarily a straight line).

[0091] In an embodiment, the first waveguide configuration 300 illustrates only a portion of the number of waveguides and corresponding pattern projectors 320A-B (e.g., FGCs) included in the intraoral scanner 200 (e.g., in the window 210). Additionally, the relative positioning (e.g., location in the substrate 312, spacing, etc.) of the waveguides 308A-B and their projection areas 320A-B may vary.

[0092] Figure 3B A second waveguide configuration for use in an intraoral scanner according to an embodiment is shown. In one embodiment, the second waveguide configuration 350 is used Figure 2B For example, the second waveguide configuration 300 may be integrated into the intraoral scanner 250. Figure 2B In an embodiment, the second waveguide configuration 350 generates a second projection field 265.

[0093] The second waveguide configuration 350 includes one or more first waveguides 368A and one or more second waveguides 368B integrated into a transparent substrate (e.g., fused silica) 362. In one embodiment, the transparent substrate has a width of about 2 mm. Other widths are also easily achievable. Each of the waveguides 368A-B includes a transmission region 360A-B, a tapered region 365A-B, and a projection region (pattern projector) 370A-B. In an embodiment, the transmission region 360A-B can be significantly longer and thinner than the other regions and can be curved. The projection region 370A-B can have a width and length configured based on the pattern and / or depth of field to be projected by the projection region 370A-B. The projection region 370A-B can be significantly wider and shorter than the transmission region 360A-B. The tapered region 365A-B can transition the width of the waveguide 368A-B between the first width of the transmission region 360A-B and the second width of the projection region 370A-B.

[0094] As shown, waveguide 368A can be configured to receive and propagate a first coherent light 355A having a first wavelength, and waveguide 368B can be configured to receive and propagate a second coherent light 355B having a second wavelength. In some embodiments, a separate light source inputs light into each waveguide 360A-B. In some embodiments, a single light source inputs light into a single waveguide 360A-B, which divides the light into a plurality of sub-waveguides. In some embodiments, a plurality of light sources are coupled to the same waveguide and project radiation of different wavelengths into the waveguide (e.g., sequentially or in parallel). Each light source can be optically connected to a waveguide having a single pattern projector 370A-B, or to a waveguide that is divided into a plurality of sub-waveguides and includes a plurality of pattern projectors 370A-B. In the second waveguide configuration 350, waveguides 368A-B are angled relative to the longitudinal axis of substrate 362 (and a probe including substrate 362), which can correspond to the Y axis. Furthermore, the projected regions 370A-B (eg, FGCs) can be divided into two or more groups, wherein the grouped projected regions 370A-B share the same orientation at an angle relative to the longitudinal axis of the substrate 362 .

[0095] In an embodiment, the second waveguide configuration 350 illustrates only a portion of the number of waveguides and corresponding pattern projectors 370A-B (e.g., FGCs) included in the intraoral scanner 250 (e.g., in the window 260). Additionally, the relative positioning (e.g., location in the substrate 362, spacing, etc.) of the waveguides 368A-B and their projection areas 370A-B may vary.

[0096] Figure 3C A third waveguide configuration 380 for use in an intraoral scanner is shown according to an embodiment. In one embodiment, the third waveguide configuration 380 is used Figure 2A Intraoral scanner 200 or Figure 2B For example, the third waveguide configuration 380 can be integrated into the intraoral scanner 250. Figure 2A Window 210 or Figure 2B In window 260.

[0097] The third waveguide configuration 380 includes at least one waveguide 398 integrated into a transparent substrate (e.g., fused silica) 382. The waveguide 398 includes a plurality of transmission regions, including a first transmission region 390A that receives a first light 385A having a first wavelength from a first light source and a second transmission region 390B that receives a second light 385B having a second wavelength from a second light source 385B. The first and second transmission regions 390A-390b can be merged into a single transmission region connected to a first tapered region 391A that connects the transmission region to the input end of a projection region 394A. Alternatively, a single transmission region can be coupled to two different light sources without using two merged transmission regions. The output end of the projection region 394A can be connected to a second tapered region 391B that tapers downward from the width of the projection region 394A to the width of another transmission region 390C. Then, another tapered region 291A can widen from the width of the transmission region 390C to the width of the next projection region 394A. This sequence may continue multiple times to form two, three, four, five, six, seven, or more projection areas 394A-B in series. In some embodiments, light of a first wavelength may propagate only through a first subset of projection areas 392A (including projection area 394A), while light of a second wavelength may pass through the first subset of projection areas 392A and also propagate through a second subset of projection areas 392B (including projection area 394B).

[0098] In one embodiment, as shown, each projected area 394A is aligned with the longitudinal axis of the substrate 382 (and the probe in which the substrate is mounted). Alternatively, the projected areas 394A may have a different orientation relative to the longitudinal axis.

[0099] In an embodiment, the third waveguide configuration 380 illustrates only a portion of the number of waves and corresponding pattern projectors 3904A-B (e.g., FGC) included in the intraoral scanner. In addition, the relative positioning (e.g., position in substrate 382, ​​spacing, etc.) of the waveguide(s) 398 and their projection regions 394A-B can vary. The length and orientation (e.g., curve, angle of line, etc.) of each transmission region 390C can vary.

[0100] Figure 4AAn example layout of a camera 420, surrounding waveguides 410, and one or more light sources 405 in an intraoral scanner according to an embodiment is shown. As shown, the waveguide 410 receives coherent light having a preconfigured wavelength from one or more light sources 405 (e.g., one or more semiconductor lasers). As shown, each waveguide 410 receives light from a different light source 405. However, some or all of the waveguides 410 may receive light from the same light source 405. Each waveguide includes a plurality of projection areas 415 (e.g., a plurality of FGCs) arranged in a substrate. The arrangement of the projection areas 415 enables a light pattern (e.g., a light spot array 425) to be projected into the field of view of the camera 420. As shown, neither the waveguide 410 nor its projection area 415 covers the camera, thereby providing an unobstructed field of view for the camera. The waveguide 410 and the projection area 415 may be arranged around the camera to provide a projected light pattern (e.g., a light spot array) to be imaged by the camera 420. Due to the size of such conventional structured light projectors, the lateral spacing between the camera and the pattern projector can be smaller than the lateral spacing between the camera and a conventional structured light projector. The minimum lateral distance (e.g., the distance in the XY plane) between the camera 420 and the closest projection area 415 is about 1-2 mm in an embodiment, or less than 2 mm in an embodiment, or less than 1 mm in an embodiment.

[0101] The concentric squares illustrate the field of view 430A-D of the camera 420 at different distances from the camera 420. In one embodiment, the camera 420 has a field of view 430A at a distance of 6 mm, a field of view 430B at a distance of 8 mm, a field of view 430C at a distance of 10 mm, and a field of view 430D at a distance of 12 mm.

[0102] Figure 4A An arrangement with only a single camera and fifty surrounding projection areas 415 is shown. However, in an embodiment, the intraoral scanner will include multiple cameras. These cameras can all be arranged in a single row or multiple rows. The cameras can have the same orientation or can have different orientations.

[0103] Figure 4B An example layout of cameras 420 grouped in a single row is shown according to an embodiment. Figure 4C Several alternative example arrangements of groups of cameras are shown.

[0104] refer to Figure 4B, the cameras 420 are arranged in a single line or row along the longitudinal axis of the probe of the intraoral scanner. Arranged around the cameras are projection areas 415 (e.g., FGC) of waveguides, each of which outputs patterned light (e.g., an array of spots). In general, the pattern output by each of the projection areas 415 forms a larger projection area across the field of view of each of the cameras 420. In the example layout, the camera has a footprint of approximately 3 mm×3 mm, and the projection field of the output patterned light has a width of approximately 12 mm. In the example shown, the intraoral scanner includes 160 projection areas arranged around the camera 420, which together generate an array of 1440 spots. In the example, the camera has a field of view 440 at a distance of 12 mm from the camera lens plane. The intraoral scanner may additionally include a plurality of incoherent light sources 430 (e.g., white light sources) arranged around the camera 420 and / or a plurality of near IR or IR light sources 435 arranged around the camera 420. Thus, the camera can generate an image of the light pattern projected onto the imaged object, an image of the imaged object illuminated by IR or near-IR radiation, and a color image of the imaged object (when the object is illuminated by white light).

[0105] Reference now Figure 4C , which is a diagram depicting a number of different configurations for the location of a camera 450 in a probe of an intraoral scanner according to some embodiments of the present disclosure. Figure 4C Note that rectangles are used to represent cameras because typically each camera sensor and the field of view β (beta) of each camera 450 have an aspect ratio of 1:2. Figure 4C Column (a) shows a bird's eye view of various configurations of the camera 450. The Y-axis labeled in the first row of column (a) corresponds to the central longitudinal axis of the intraoral scanner probe. Column (b) shows a side view of the camera 450 in various configurations as seen from a line of sight coaxial with the central longitudinal axis of the probe. Column (b) shows the camera 450 positioned with the optical axes 454 at an angle of 90 degrees or less relative to each other (e.g., 35 degrees or less). Column (c) shows a side view of the camera 450 in various configurations as seen from a line of sight perpendicular to the central longitudinal axis of the probe.

[0106] Typically, the farthest side (towards Figure 4C in the positive Y direction) and the nearest side (towards Figure 4CThe cameras 450 (i.e., the negative Y direction in the probe) are positioned so that their optical axes 454 are slightly rotated inwardly relative to the next closest camera 450, such as at an angle of 90 degrees or less, such as 35 degrees or less. The more centrally positioned cameras 450, i.e., not the most distal camera 450 nor the most distal camera 450, are positioned to face directly outside the probe with their optical axes 454 being substantially perpendicular to the central longitudinal axis of the probe.

[0107] Typically, the number of cameras 450 in the probe can vary from four (as shown in rows (iv) and (v)) to seven (as shown in row (ix)). Note that Figure 4C The various configurations shown in are exemplary and non-limiting, and the scope of the present disclosure includes additional configurations not shown. For example, the scope of the present disclosure includes more than seven cameras positioned in the probe.

[0108] In an example application, a device for intraoral scanning (e.g., an intraoral scanner) includes: an elongated handheld wand including a probe at a distal end of the elongated handheld wand; a plurality of waveguides including an array of FGCs disposed within the probe; and at least four cameras disposed within the probe. Each FGC may generate a light pattern when light is transmitted through the FGCs. Each of the at least four cameras may include a camera sensor and one or more lenses, wherein each of the at least four cameras is configured to capture a plurality of images depicting at least a portion of the projected light pattern on an intraoral surface. In one embodiment, the at least four cameras may be arranged in at least two rows, each of the at least two rows being substantially parallel to a longitudinal axis of the probe, the at least two rows including at least a first row and a second row.

[0109] In another application, the farthest camera along the longitudinal axis and the closest camera along the longitudinal axis of the at least four cameras are positioned so that their optical axes are at an angle of 90 degrees or less to each other from a line of sight perpendicular to the longitudinal axis. The cameras in the first row and the cameras in the second row can be positioned so that from a line of sight coaxial with the longitudinal axis of the probe, the optical axes of the cameras in the first row are at an angle of 90 degrees or less relative to the optical axes of the cameras in the second row. Except for the farthest camera and the closest camera, the remaining cameras of the at least four cameras have optical axes substantially parallel to the longitudinal axis of the probe. Each of the at least two rows may include an alternating sequence of light projectors and cameras.

[0110] In another application, the farthest camera along the longitudinal axis and the closest camera along the longitudinal axis are positioned so that their optical axes are at an angle of 35 degrees or less to each other relative to a line of sight perpendicular to the longitudinal axis. The cameras in the first row and the cameras in the second row can be positioned so that the optical axes of the cameras in the first row are at an angle of 35 degrees or less relative to the optical axes of the cameras in the second row from a line of sight coaxial with the longitudinal axis of the probe.

[0111] In another application, the at least four cameras may have a combined field of view of 25-45 mm along the longitudinal axis and a field of view of 20-40 mm along the z-axis corresponding to the distance from the probe.

[0112] Figure 5A A perspective view of an example waveguide 500 is shown, according to an embodiment, comprising a focusing grating coupler 508 coupled to a laser 502 via a coupling 511. The waveguide 500 is formed in a substrate 501 (e.g., a SiO2 or glass substrate). Regions of the substrate 501 may be doped to form the waveguide 500. The laser 502 may be coupled to the waveguide 500 and may project light into the waveguide. In some embodiments, the laser 502 may be coupled to a transmission region 504 of the waveguide 500 via a coupling 511, which may include at least one of a lens, a prism, or a grating.

[0113] The waveguide 500 includes a transmission region 504, followed by a tapered region 506, and terminates at a FGC 508. In the example shown, the FGC 508 has a width and length of 150 microns, and the transmission region 504 of the waveguide has a width and depth of approximately 1-5 microns. However, other FGC sizes and / or transmission region sizes may also be used. The FGC 508 may include a grating pattern formed in the surface of the substrate 501 that focuses a light pattern at a focal depth f. The FGC 508 may be designed so that the focal length f is a focal range corresponding to the focal range of the camera. In an embodiment, the patterned light output by the FGC 508 has an approximately constant overlap (and therefore an approximately constant focus) over the entire focal depth of the camera of the intraoral scanner.

[0114] The waveguide 500 can guide light waves with low loss to the surrounding medium. In an embodiment, the doped region of the substrate 501 forming the waveguide can have a depth of sub-micron size. The waveguide 500 can be designed for a specific wavelength or mode. The first mode distribution can be similar to a Gaussian beam distribution. For example, the doped region of the substrate can be ion-doped with one or more conventional dopants and can be formed by a nano-fabrication process.

[0115] Figure 5BA perspective view of an example waveguide 500 is shown that includes a focusing grating coupler 508 coupled to a laser 502 without the use of a coupling member in accordance with an embodiment. The waveguide 500 is formed in a substrate 501 (e.g., a SiO2 or glass substrate). Regions of the substrate 501 can be doped to form the waveguide 500 and / or can be etched to form the waveguide 500. The laser 502 can be coupled to the waveguide 500 and can project light into the waveguide. In one embodiment, the light source(s) 154 are optically coupled to the one or more waveguides directly (e.g., by a direct connection between a laser chip or optical fiber and the edge of the waveguide).

[0116] The waveguide 500 also includes a tapered region 505 and a transmission region 504, followed by an additional tapered region 506, and terminates at a FGC 508. In an embodiment, the tapered region 505 can taper to a narrow width (e.g., to a point). In some embodiments, multiple tapered edge couplers (e.g., multiple tapered regions 505), such as 3-5 tapered edge couplers (e.g., 3-5 tapered regions), can be manufactured to merge into a single transmission region 504. This can increase the coupling efficiency of the waveguide. In an embodiment, the multiple tapered regions 505 can each receive light from the laser 502 and can merge the light at the transmission region 504. In the example shown, the FGC 508 has a width and length of 150 microns, and the tapered region 505 of the waveguide has a width and depth of about 1-5 microns where it meets the transmission region. In an embodiment, the transmission region can have a width and depth of about 1-5 microns. However, other FGC sizes and / or transmission region sizes and / or tapered region sizes can also be used. The FGC 508 may include a grating pattern formed in the surface of the substrate 501 that focuses the light pattern at a focal depth f. The FGC 508 may be designed so that the focal length f is a focal range that corresponds to the focal range of the camera. In an embodiment, the patterned light output by the FGC 508 has an approximately constant overlap (and therefore an approximately constant focus) across the focal depth of the camera of the intraoral scanner.

[0117] The waveguide 500 can guide light waves with low loss to the surrounding medium. In an embodiment, the doped region of the substrate 501 forming the waveguide can have a depth of sub-micron size. The waveguide 500 can be designed for a specific wavelength or mode. The first mode distribution can be similar to a Gaussian beam distribution. For example, the doped region of the substrate can be ion doped with one or more conventional dopants and can be formed via a nanofabrication process.

[0118] Figure 6A top view of a focusing grating coupler for use in a waveguide according to an embodiment is shown. As shown, the FGC includes a groove pattern etched into a substrate. The grooves may be curved and / or with frequency variations so that their average period is on the scale of the wavelength of light to be irradiated through the waveguide 500. In an embodiment, the depth of the grooves may be on the order of one hundred to several hundred nanometers. In some embodiments according to the holographic principle, the configuration causes the propagation mode of the projected light traveling through the waveguide 500 to be emitted and enter free space at an angle to the plane of the substrate 500 (e.g., approximately orthogonal to the plane) and to focus at a focal length f in the Z direction (orthogonal to the plane of the substrate 500). In general, the FGC forces light to couple out of the waveguide. The period and curvature of the grooves may be designed for the target wavelength of light, the target projection pattern, the target focal length (or focal length range), and the output angle (e.g., relative to the plane of the substrate 508 and / or relative to the Y axis). In order to generate a pattern of one or more projected light spots, in the embodiment shown, the pattern in the FGC may resemble concentric ellipses or curves. In the illustration, the dark areas represent the surface of the substrate and the light areas are grooves etched into the substrate. The left rectangle shows a magnified view of a small area within the focusing grating coupler.

[0119] Fig. 7A A perspective view of an example waveguide according to an embodiment is shown, the waveguide including a focusing grating coupler configured to output patterned light having a first focused spot pattern. The FGC can be divided into a grid of regions (e.g., a square or rectangular grid). In each region of the grid, the grooves of the FGC can be misaligned along the Y-axis relative to adjacent regions, for example, by about 40-100 nm. This modification of the FGC pattern causes the outcoupled light (e.g., an outcoupled beam) to be split into multiple focused beams (e.g., 9 focused beams) having the same focal length as the outcoupled beam of the undisturbed FGC. In one embodiment, the efficiency of the FGC that splits the outcoupled pattern into 9 spots is about 31%, and the efficiency of each individual spot is about 3.5%.

[0120] Figure 7C An FGC region divided into a 10×10 square grid is shown, which produces an array of 9 focused spots arranged in a 3×3 array. In an embodiment, the curved grating regions that provide different phases to the outcoupled light are achieved by shifting the grating pattern by a fixed amount (e.g., 40-80 nm, about 60 nm, etc.) between the grating patterns of adjacent regions in the grid. Fig. 7A A 3 x 3 array of focused spots is shown. The focused spots are evenly spaced, with a spacing D between adjacent spots at focal length f.

[0121] Figure 7BA perspective view of an example waveguide according to an embodiment is shown, the waveguide including a group of focusing grating couplers (e.g., nine FGCs, each FGC similar to the FGC in FIG. 5 ) configured to output patterned light having a second focused spot pattern. In one embodiment, the FGC is shown with a reflector disposed below the FGC to improve the outcoupling efficiency. In an embodiment, the dimensions of the FGC are approximately 100×100 microns. In one embodiment, the length of the FGC is approximately 300 microns. In one embodiment, the efficiency of the FGC is approximately 50%.

[0122] Figure 8 A top view of a focusing grating coupler design of an output spot pattern according to an embodiment is shown. The FGC design shown has a length and width of about 100 microns and is divided into patches with a period Λ of about 10 microns. d , and the grating offset Δy between adjacent blocks is about 85 nm. The FGC shown has an efficiency of about 30% for a projection pattern of 9 spots. For example, to generate 600 spots, 8×8 FGCs can be used, which have a total size of about 0.8×0.8 mm.

[0123] Fig. 9 A perspective view of an example waveguide according to an embodiment is shown, the waveguide including a focusing grating coupler 908 configured to output patterned light having a second focused spot pattern and / or other patterns and a microlens array 925 above the focusing grating coupler 908. As shown, a laser 902 can be coupled to a waveguide. The waveguide can include a transmission region 904, a tapered region 906, and an FGC 908. One or more spacers 920 (optionally formed of fused silica, glass, or other materials) can position and hold the microlens array 925 above the FGC 908. According to the diffraction grating principle, the microlens array 925 can divide the outcoupled beam emitted from the FGC into several modes with different angles according to the period and refractive index of the microlens array (MLA). Therefore, in an embodiment, the number of spots or other patterns can be increased by adding a microlens array above the FGC. In one embodiment, a single FGC used with the MLA has a length of about 100 microns and an efficiency of about 50%.

[0124] Figure 10A-10B A diagram showing a focusing grating coupler according to an embodiment is shown, which shows how to design a focusing grating coupler for use in an intraoral scanner. Fig. 10A, changing the grating period allows different angles θ of the outcoupled light, so that the FGC acts as a simple lens. The FGC acts as a lens, F#=f / D, where D is the size of the FGC and f is the focal length. The use of FGC can achieve focal lengths of 1.5 mm up to several centimeters, where the beam focus reaches the diffraction limit and / or the beam diameter is as low as 1 micron. Coupling efficiencies of up to 90% have been demonstrated. The grating pattern of the FGC is similar to a holographic recording pattern. The pattern is the interference pattern of a beam of the desired pattern (e.g., a spot, a line, etc.) and the waveguide. For a focused beam (spherical wave), the grating pattern is similar to a Fresnel zone plate pattern for a specific wavelength. Turning to the accompanying drawings, k1 is the incident waveguide vector, c is the focused wave, f is the focal length, and θ is the outcoupling angle. In the example shown, the waveguide is formed of doped SiO2 on a SiO2 substrate. However, the waveguide and substrate can be any material mentioned herein.

[0125] Go to Fig. 10B , the coupling efficiency of the out-coupled mode power P1 is reduced by two parasitic modes with powers P2 and P3, where P2 is the power of the substrate-coupled mode lost through the bottom of the FGC and P3 is the power of the backscattered mode lost through back reflection in the longitudinal direction of the FGC. The amount of power of the pattern or other light coupled out of the FGC, and therefore the efficiency of the FGC, can be calculated according to the following equation:

[0126]

[0127] Where α1 is the coupling coefficient with the outgoing mode, α tot is the sum of the coupling coefficients of all modes, and L is the lateral position (i.e., grating length) entering the FGC along the longitudinal axis (Y axis). As shown, G(y) is the intensity distribution of P1, indicating that for a grating with equal depth h per groove, constant duty cycle dc, and constant grating period Λ, P1 decreases as the length Y entering the FGC increases. The reduction of parasitic modes P2 and P3 increases the intensity of the outcoupled mode P1. The parasitic mode P2 can be reduced by adding a reflective substrate or coating (e.g., a metal layer of a Bragg reflector composed of several layers of alternating reflections), which will reflect P2 toward the grating. In an embodiment, the reflector is configured so that P2 interferes constructively with P1. Even without a reflector, efficiency can be increased if the waveguide depth allows constructive interference.

[0128] Increasing the depth of a particular groove of the FGC increases the intensity of the light emitted by that portion of the grating. Therefore, the intensity uniformity of the FGC can be improved by gradually adjusting the depth of the groove so that the depth increases with the length L. This can cause the intensity distribution G(y) to become approximately a horizontal line. Similarly, the duty cycle dc also affects the efficiency. In one embodiment, both the depth of the groove and the duty cycle dc can be adjusted over the length L of the FGC to provide a uniform intensity distribution g(y).

[0129] As previously discussed, changing the wavelength of light irradiated into the FGC causes the focus, angle of the outcoupled modes, and output pattern to change. In an embodiment, two or more different wavelengths of light may be irradiated through the FGC in series or in parallel to generate different projected light patterns.

[0130] According to an example, a user (e.g., a practitioner) can perform an intraoral scan of a patient. In doing so, the user can apply the intraoral scanner 100 to one or more intraoral locations of the patient. The scan can be divided into one or more segments. As an example, a segment can include the patient's lower dental arch, the patient's upper dental arch, one or more prepared teeth of the patient (e.g., teeth of the patient to which a dental device such as a crown or other dental restoration will be applied), one or more teeth in contact with the prepared teeth (e.g., the tooth itself is not affected by the dental device, but it is located near one or more such teeth or engages with one or more such teeth when the mouth is closed), and / or the patient's bite (e.g., the scan is performed when the patient's mouth is closed, and the scan is directed toward the engagement area of ​​the patient's upper and lower teeth). Via such scanner application, the scanner 100 can provide intraoral scan data to a computing device. The intraoral scan data can be provided in the form of an intraoral scan / image dataset, each of which can include a 2D intraoral scan / image and / or a 3D intraoral scan / image of a specific tooth and / or intraoral location area. In one embodiment, separate scan / image datasets are created for the maxillary arch, the mandibular arch, the patient's bite, and each prepared tooth. Alternatively, a single large intraoral scan / image data set is generated (e.g., for the mandibular arch and / or the maxillary arch). Such a scan / image can be provided from the scanner to the computing device in the form of one or more points (e.g., one or more pixels and / or groups of pixels). For example, the scanner 100 can provide such a 3D scan / image as one or more point clouds.

[0131] The manner in which the patient's mouth is scanned may depend on the procedure being applied to it. For example, if an upper or lower denture is to be fabricated, the mandibular or maxillary edentulous dental arch may be fully scanned. In contrast, if a dental bridge is to be fabricated, only the portion of the entire dental arch that includes the edentulous area, adjacent prepared teeth (e.g., abutment teeth), and the opposing dental arch and dentition may be scanned. Additionally, the manner in which the oral cavity is to be scanned may depend on the physician's scanning preferences and / or the patient's condition.

[0132] As a non-limiting example, dental procedures can be roughly divided into restorative (restoration) procedures and orthodontic procedures, and then further subdivided into specific forms of these procedures. In addition, dental procedures can include identification and treatment of gum disease, sleep apnea and intraoral conditions. The term "restorative procedure" refers in particular to any procedure involving the oral cavity, the purpose of which is to design, manufacture or install a dental restoration in a dental part (intraoral position) in the oral cavity or its real or virtual model, or the purpose is to design and prepare an intraoral position to receive such a restoration. For example, a restoration can include any restoration, such as a crown, a veneer, an inlay, a retainer, an implant and a bridge, and any other artificial partial or full denture. The term "orthodontic procedure" refers in particular to any procedure involving the oral cavity, the purpose of which is to design, manufacture or install an orthodontic element in an intraoral position in the oral cavity or its real or virtual model, or the purpose is to design and prepare an intraoral position to receive such an orthodontic element. These elements can be appliances, including but not limited to brackets and archwires, retainers, invisible braces or functional appliances.

[0133] During an intraoral scanning session, an intraoral scanning application receives and processes intraoral scan data (e.g., an intraoral scan) and generates a 3D surface of a scanned area of ​​the oral cavity (e.g., a dental site) based on such processing. To generate the 3D surface, the intraoral scanning application may register and "stitch" or merge together intraoral scans generated from the intraoral scanning session in real time or near real time as the scans are performed. In one embodiment, performing the registration includes capturing 3D data for various points of the surface in multiple scans (views from a camera) and registering the scans by calculating transformations between the scans. The 3D data may be projected into 3D space for transformation and stitching. The scans may be integrated into a common reference frame by applying appropriate transformations to points of each registered scan and projecting each scan into 3D space.

[0134] In one embodiment, registration is performed on adjacent or overlapping intraoral scans (e.g., each consecutive frame of an intraoral video). In one embodiment, registration is performed using hybrid scans and / or reduced or cropped scans. A registration algorithm is performed to register two or more adjacent intraoral scans and / or to register an intraoral scan with an already generated 3D surface, which essentially involves determining a transformation that aligns one scan with another scan and / or a 3D surface. Registration can involve identifying multiple points in each scan (e.g., a point cloud) of a scan pair (or a scan and a 3D model), performing surface fitting on these points, and matching points of the two scans (or scans and a 3D surface) using a local search around the points. For example, an intraoral scanning application can match points of one scan with the nearest points interpolated on the surface of another image, and iteratively minimize the distance between matching points. Other registration techniques can also be used. The intraoral scanning application can repeat the registration and stitching for all scans of the intraoral scanning sequence, and update the 3D surface as the scans are received.

[0135] When the scanning session is complete (e.g., all scans of the intraoral site or dental part have been captured), the intraoral scanning application can generate a virtual 3D model (also referred to as a digital 3D model) of the one or more scanned dental parts. The virtual 3D model includes the 3D surfaces of the one or more scanned dental parts, but has a higher degree of accuracy than the 3D surfaces generated during the scanning process. In order to generate the virtual 3D model, the intraoral scanning application can register and "stitch" or merge the intraoral scans generated from the intraoral scanning session together. In one embodiment, the registration is performed on adjacent and / or overlapping intraoral scans (e.g., each consecutive frame of an intraoral video). In one embodiment, the registration is performed using blended scans and / or reduced or cropped scans. A registration algorithm can be executed to register two or more adjacent intraoral scans and / or to register the intraoral scans with a 3D model, which essentially involves determining a transformation that aligns one scan with another scan and / or with a 3D model. Registration can involve identifying multiple points in each scan (e.g., point cloud) of a scan pair (or a scan and a 3D model), fitting a surface to those points, and matching the points of the two scans (or scan and 3D model) using a local search around the points. For example, an intraoral scanning application can match points of one scan to the nearest points interpolated on the surface of the other scan and iteratively minimize the distance between the matched points. Other registration techniques can also be used. Registration and stitching performed to generate a 3D model can be more accurate than registration and stitching performed to generate a 3D surface that is shown in real time or near real time during the scanning process.

[0136] The intraoral scanning application can repeat the registration for all scans of the intraoral scanning sequence to obtain a transformation for each scan to align each scan with the previous one and / or with a common reference frame (e.g., with a 3D model). The intraoral scanning application integrates all scans into a single virtual 3D model by applying appropriately determined transformations to each scan. Each transformation can include rotations around one to three axes and translations in one to three planes.

[0137] In one embodiment, the intraoral scanning application includes a treatment planner configured to perform treatment planning for orthodontic treatment and / or restorative treatment. The treatment planner may additionally perform dental diagnostics and / or prognostics. In an embodiment, the treatment planner generates an orthodontic treatment plan that includes a 3D model for a final tooth arrangement and a 3D model for one or more intermediate tooth arrangements.

[0138] The following non-limiting examples can help to more fully understand the process. Patients who wish to straighten their teeth may choose Invisalign Treatment. Invisalign is the process of creating a custom set of invisible aligners specifically for the patient. The invisible aligners are worn over the patient's teeth and gradually shift the patient's teeth. A new set of aligners may be worn after a specified period of time (e.g., two weeks) until treatment is complete.

[0139] The patient can visit a dentist or orthodontist to begin Invisalign treatment. The dentist can scan the patient's teeth using the intraoral scanner 100 in a scanning mode. The dentist can use the scanner 100 to capture the patient's tooth segments (e.g., upper dental arch, lower dental arch, occlusal segment) in one or more sets of intraoral scans. The intraoral scanning application can align and stitch the intraoral scans together to create a 3D rendering of the scanned segment and present the 3D rendering to the dentist. Once the scan is complete, the dentist can then navigate to an image processing mode that can generate a virtual 3D model by aligning and stitching the intraoral images together. Once a set of appropriate 3D renderings and / or virtual 3D models are completed, the 3D renderings and / or 3D models can be saved to the patient profile.

[0140] The dentist can then provide input to switch to a planning mode in which a final tooth arrangement can be determined and one or more intermediate tooth arrangements can be determined. A treatment plan can be generated to provide a progression of treatment stages from the patient's initial tooth arrangement to a target final tooth arrangement, with a separate 3D model associated with each treatment stage.

[0141] Once a set of appropriate 3D models are generated, the 3D models can be saved to the patient profile. The dentist can then navigate to the delivery mode to electronically send the completed patient profile to the processing center. The processing center can then generate a customized series of invisible braces for the patient and deliver the invisible braces to the dentist. The patient will then return to the dentist to receive the first set of invisible braces and verify that the invisible braces are correctly fitted to the patient's teeth.

[0142] It should be understood that the above description is intended to be illustrative rather than limiting. Upon reading and understanding the above description, many other embodiments will be apparent. Although embodiments of the present disclosure have been described with reference to specific example embodiments, it will be appreciated that the present disclosure is not limited to the described embodiments, but may be implemented with modifications and changes within the spirit and scope of the appended claims. Therefore, the description and drawings should be regarded as illustrative rather than restrictive. Therefore, the scope of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents of these claims.

Claims

1. An intraoral scanner, comprising: an elongated rod including a probe at a distal end of the elongated rod; one or more light sources disposed within the elongated rod distal to the distal end of the probe, wherein the one or more light sources are configured to generate unpatterned light; one or more waveguides disposed within the probe, wherein the one or more waveguides are configured to receive the unpatterned light generated by the one or more light sources and output patterned light from one or more locations at a distal end of the probe; and One or more image sensors are disposed at the distal end of the probe, wherein the one or more image sensors are configured to capture images of an intraoral object illuminated by the patterned light.

2. The intraoral scanner according to claim 1, wherein: The one or more waveguides include one or more pattern projectors at a distal end of the probe, wherein each pattern projector outputs at least a portion of the patterned light.

3. The intraoral scanner according to claim 2, wherein: Each of the one or more pattern projectors includes a focusing grating coupler.

4. The intraoral scanner according to claim 3, wherein: At least one focusing grating coupler is configured to output a spot pattern.

5. The intraoral scanner according to claim 4, wherein: The light spot pattern includes four to sixteen light spots with uniform intervals.

6. The intraoral scanner according to claim 2, wherein: Each of the one or more waveguides includes: a transmission region having a first width; a pattern projector region including the pattern projector, the pattern projector region having a second width greater than the first width; and a tapered region between the transmission region and the pattern projector region, the tapered region transitioning from the first width to the second width.

7. The intraoral scanner of claim 2, further comprising: A microlens array is disposed above each of the one or more pattern projectors.

8. The intraoral scanner according to claim 1, wherein: The one or more waveguides include at least one waveguide configured to: receiving the unpatterned light from a light source of the one or more light sources; The unpatterned light is split into a plurality of paths, wherein each of the plurality of paths includes a different pattern generator configured to output a portion of the patterned light.

9. The intraoral scanner according to claim 8, wherein: Each of the different pattern generators includes a focusing grating coupler.

10. The intraoral scanner according to claim 1, wherein: The probe includes a longitudinal axis, wherein each of the one or more image sensors has an angle of 45 degrees to 135 degrees with the longitudinal axis, and wherein the patterned light is projected from the one or more locations at the distal end of the probe at one or more angles of 45 degrees to 135 degrees with the longitudinal axis.

11. The intraoral scanner according to claim 10, wherein: A lateral distance between the one or more locations at the distal end of the probe and the one or more image sensors within a plane defined at least in part by a longitudinal axis of the probe is less than 2 mm.

12. The intraoral scanner according to claim 1, wherein: The patterned light has approximately constant overlap across the focal depth of the intraoral scanner.

13. The intraoral scanner according to claim 1, wherein: All light rays in the patterned light output from specific positions among the one or more positions are substantially parallel to each other.

14. The intraoral scanner according to claim 13, wherein: A first light ray in the patterned light output from a first position among the one or more positions has a first angle relative to a plane defined at least in part by the longitudinal axis of the probe, and wherein a second light ray in the patterned light output from a second position among the one or more positions has a second angle relative to the plane defined at least in part by the longitudinal axis.

15. The intraoral scanner according to claim 1, wherein: The one or more light sources include a first light source that outputs first coherent light having a first wavelength and a second light source that outputs second coherent light having a second wavelength, wherein the same waveguide of the one or more waveguides is used to transmit the first coherent light and the second coherent light to the one or more locations at the distal end of the probe.

16. The intraoral scanner of claim 1, further comprising: At least one of a lens, a prism, or a grating coupling a light source of the one or more light sources to a waveguide of the one or more waveguides.

17. The intraoral scanner according to claim 1, wherein: The one or more light sources are directly coupled to the one or more waveguides.

18. The intraoral scanner of claim 1, wherein: The one or more waveguides include a first plurality of waveguides; and The one or more light sources include a plurality of semiconductor lasers.

19. The intraoral scanner of claim 1, further comprising: A refractive coating is located at the one or more locations on at least one surface of the one or more waveguides.

20. The intraoral scanner of claim 1, further comprising: A first plate in the probe, wherein the first plate covers at least a first subset of the one or more image sensors such that return light from an imaged intraoral object passes through the first plate to the first subset of the one or more image sensors, wherein the first plate includes at least a first subset of the one or more waveguides.

21. The intraoral scanner of claim 20, further comprising: A second plate in the probe is arranged on the first plate so that the second plate also covers at least a first subset of the one or more image sensors, wherein the second plate includes at least a second subset of the one or more waveguides, wherein the first subset of the one or more waveguides outputs the patterned light from the first subset of the one or more positions, and wherein the second subset of the one or more waveguides outputs the patterned light from the second subset of the one or more positions, and the second subset does not overlap with the first subset of the one or more positions.

22. The intraoral scanner of claim 20, wherein: The first plate has a first orientation relative to a plane defined at least in part by a longitudinal axis of the probe, the intraoral scanner further comprising: a second plate in the probe, wherein the second plate covers at least a second subset of the one or more image sensors such that return light from an imaged intraoral object passes through the second plate to the second subset of the one or more image sensors, wherein the second plate includes at least a second subset of the one or more waveguides, and wherein the second plate has a second orientation relative to the plane defined at least in part by the longitudinal axis of the probe.

Images