Intraoral scanning device with supply assembly unit

Abstract

According to an embodiment, an intraoral scanning device is disclosed. The apparatus is configured to acquire intraoral scan data from a three-dimensional dental object. The intraoral scanning device comprises: a projector unit configured to emit light at least onto a dental object of a patient, and wherein the projector unit comprises one or more light sources; an image sensor configured to acquire reflected light from at least the dental object; the processing unit is configured to process the acquired reflected light into 2D (two-dimensional) intraoral scanning data and / or 3D (three-dimensional) intraoral scanning data; a battery unit configured to supply a DC voltage; a supply component unit configured to receive a DC voltage and provide a supply voltage to the one or more light sources, and the supply component unit includes: a boost converter configured to convert the DC voltage to the supply voltage, where the DC voltage is lower than the supply voltage; a buck converter configured to convert the DC voltage to a supply voltage such that the DC voltage is higher than the supply voltage; and a voltage controller unit configured to control the boost converter and the buck converter.

Description

Technical Field

[0001] The present disclosure relates to a supply assembly unit for one or more light sources of an intraoral scanning device for scanning a dental object. Background Art

[0002] The intraoral scanning device is configured to perform scanning of a dental object. The intraoral scanning device performs scanning by projecting light and capturing reflected light from the dental object. Over the years, scanning methods have become more and more complex and may include scanning using multiple light sources with different wavelengths. In order to maintain the real-time scanning behavior of the intraoral scanning device, a fast processor and fast switching between multiple light sources are required. In addition, as more and more functions are added to the intraoral scanning device, power consumption should also be reduced. Summary of the invention

[0003] One aspect of the present disclosure is to achieve an intra-oral scanning device for eliminating means for turning power on and off to one or more light sources while still achieving modulation of the current to the one or more light sources.

[0004] Another aspect of the present disclosure is to obtain an intraoral scanning device having rapid on and off switching of a set of one or more light sources, the device being adapted to perform scanning in different modalities. The modalities may include a first light source configured to emit light within a first wavelength range, and then at least a second light source configured to emit light within a second wavelength range.

[0005] Yet another aspect is to provide an intra-oral scanning device having a supply assembly unit for one or more light sources that is simple and cost-effective to manufacture.

[0006] A further aspect is to provide an intraoral scanning device that is more power efficient.

[0007] According to this aspect, an intraoral scanning device is disclosed. The intraoral scanning device can be configured to acquire intraoral scanning data from a three-dimensional dental object. The three-dimensional object can be a tooth, multiple teeth and / or gums in the patient's mouth. The intraoral scanning device may include a projector unit configured to emit light at least onto the patient's dental object, and wherein the projector unit includes one or more light sources. The one or more light sources may include at least one light emitting diode (LED) configured to emit light having a first wavelength range.

[0008] The one or more light sources may include a second light source configured to emit light having an emission maximum within a first sub-range of the first wavelength range.

[0009] The one or more light sources may include a second light source adapted to emit light having an emission maximum within a first sub-range of the first wavelength range.

[0010] The one or more light sources may include a second light source configured to emit light having a second wavelength range, and wherein the first and second wavelength ranges include different wavelengths.

[0011] The one or more light sources may be configured to emit light having a first wavelength range, and wherein the first wavelength range is characterized by having a color rendering index (CRI) of at least 70. The advantage of having a CRI of at least 70 provides an intraoral scanning device capable of revealing the color of a dental object that is faithful to the correct color of the dental object.

[0012] One or more light sources may be light emitting diodes (LEDs). One or more light sources may include a first group of light sources, wherein the first group of light sources may be configured to emit light within a first wavelength range. One or more light sources may include a second group of light sources, wherein the second group of light sources may be configured to emit light within a second wavelength range. One or more light sources may include another group of light sources configured to emit light within different wavelength ranges. The light sources in the light source group may be connected in a series arrangement. One or more light sources may include a first light source configured to emit light within a first wavelength range, and one or more light sources may include a second light source configured to emit light within a second wavelength range. The first wavelength range and the second wavelength range may be different. The intraoral scanning device may be configured to perform a scan of a dental object by changing the wavelength of the emitted light. For example, the first wavelength range may include an infrared wavelength, and the second wavelength range may include a white wavelength and / or a colored wavelength, such as red, blue, or green. In the case of scanning, the intraoral scanning device may switch between infrared light and white light.

[0013] The one or more light sources may include a laser configured to emit light at wavelengths such as red, blue, green, white, and infrared. The one or more light sources may include multiple lasers configured to emit light at different wavelengths, such as red, blue, green, and infrared wavelengths.

[0014] The intraoral scanning device may further include an image sensor configured to acquire reflected light from at least the dental object. The image sensor may be a charge coupled device (CCD) image sensor, an active pixel (CMOS) image sensor, and / or a hybrid CCD and CMOS image sensor. The image sensor may be a monochrome sensor or a color sensor.

[0015] The intraoral scanning device may include a processing unit configured to process the acquired reflected light into two-dimensional (2D) intraoral scanning data and / or three-dimensional (3D) intraoral scanning data. The 2D intraoral scanning data may be suitable for generating a three-dimensional model of a dental object. The processing unit may be configured to perform quality improvement image processing on the 2D intraoral scanning data, and based on the improved 2D intraoral scanning data, the processing unit is configured to generate a three-dimensional model of the dental object. The three-dimensional model may depict the patient's oral cavity, including teeth and gums. In another example, the three-dimensional model may be an impression of the patient's oral cavity.

[0016] The processing unit can operate in real time, which means that the acquired reflected light is processed into 2D intraoral scan data and / or 3D intraoral scan data within a few milliseconds, and the processed data can be displayed graphically on the display unit almost immediately.

[0017] The processing unit may be configured to determine surface information from the acquired reflected light and generate 2D intra-oral scan data and / or 3D intra-oral scan data in real-time.

[0018] The processing unit may be configured to determine surface information from the acquired reflected light in real time and generate a three-dimensional (3D) surface model of the dental object using the surface information. The 3D surface model may be determined based on a volumetric method including stitching of 2D intraoral scan data and / or 3D intraoral scan data.

[0019] The intraoral scanning device may include a wireless interface configured to transmit a three-dimensional (3D) surface model in real time. The intraoral scanning device may transmit data or a model to an external device via the wireless interface. The external device may be configured to display the received data and / or model. In one example, the intraoral scanning device may transmit 2D intraoral scanning data, which is processed by the intraoral scanning device into a 2D image ready to be displayed, or processed into a raw 2D image, wherein the 2D image is not ready to be displayed, but only ready to be wirelessly transmitted to an external device. In this example, the external device may be configured to perform additional processing on the received 2D intraoral scanning data, processing it into 3D intraoral scanning data or a 3D surface model representing the scanned dental object. In another example, the external device may transmit 3D intraoral scanning data to the external device, and in this example, the external device is configured to display the 3D intraoral scanning data or perform additional processing of the 3D intraoral scanning data into a 3D surface model. In yet another example, the external device may receive a 3D surface model from the intraoral scanning device, and the 3D surface model is ready to be displayed by the external device.

[0020] The intraoral scanning device may include a battery unit configured to supply power to the intraoral scanning device. The battery unit may be configured to supply a direct current (DC) voltage. The battery unit may include a single battery or a plurality of batteries connected in series. The intraoral scanning device may include a DC voltage source having first and second supply terminals. The battery unit may include one or more of the following batteries:

[0021] Lithium-ion,

[0022] Nanotube lithium ion,

[0023] Zinc manganese oxide,

[0024] Zinc air,

[0025] Silicone electrolyte,

[0026] Gold nanowire gel electrolyte,

[0027] Tanktwo string (String),

[0028] Silicon anode lithium ion,

[0029] Lithium-sulfur batteries, and

[0030] Solid-state lithium-ion.

[0031] The intraoral scanning device may include a supply assembly unit configured to receive a DC voltage and provide a supply voltage to one or more light sources. The supply assembly unit may include multiple units arranged in a single component or distributed in multiple components. The supply assembly unit mainly refers to the components of the supply assembly unit operating as a unit, which exchanges signals, forwards signals between components, and / or receives / transmits signals from / to at least other components of the supply assembly unit.

[0032] The supply component unit may include: a voltage up-converter configured to convert a DC voltage into a supply voltage, wherein the DC voltage is lower than the supply voltage; a voltage down-converter configured to convert a DC voltage into the supply voltage, such that the DC voltage is higher than the supply voltage; and a voltage controller unit configured to control the voltage up-converter and the voltage down-converter.

[0033] The voltage controller unit may be configured to control the boost converter and the buck converter via a control signal, which may include an enable signal and a current magnitude signal to the one or more light sources. The enable signal indicates whether the one or more light sources should be turned on or off, and the current magnitude signal sets the current level of the one or more light sources that are turned on.

[0034] The voltage controller unit may be configured to control the boost converter and the buck converter based on a scan sequence. The scan sequence may be stored in a memory of the intraoral scanner or the intraoral scanner system. The scan sequence determines when and which of the one or more light sources should be turned on and off. For example, the one or more light sources may include a group of white LED light sources and a single infrared LED light source, and during the scan sequence, the intraoral scanning device is configured to switch between the group of white LED light sources and the single infrared (IR) LED light source. Fast on-off switching allows multiple images of an object to be captured using different light sources with different wavelengths. Fast on-off switching enables intraoral scan data to be captured using a white LED light source and other intraoral scan data to be captured using an IR LED light source, and the intraoral scan and the other intraoral scan data include image data related to the same object. Without fast on-off switching, further and more complex image processing would be required to correlate the intraoral scan data and the other intraoral scan data.

[0035] The voltage controller unit can be configured to control the boost converter and the buck converter by the timing at which each of the one or more light sources is turned on and off (i.e., on-off timing). The scanning sequence can also include the current level of each of the one or more light sources. The timing and current level of each of the one or more light sources can be stored in the memory of the intraoral scanner or the intraoral scanner system.

[0036] In one example, the scanning sequence may include a first sequence in which white pulses are emitted and a subsequent scanning sequence (i.e., a second scanning sequence) which may include white pulses and blue pulses that are turned on and off in succession. In another example, the second scanning sequence may include white pulses, blue pulses, and infrared pulses that are turned on and off in succession. In yet another example, the second scanning sequence may include white pulses and blue pulses that are turned on and off in succession while the IR power is constant at a certain current level.

[0037] One or more light sources may be turned off. Turning off may mean turning down to a current level that makes the light source irrelevant to scanning, ie the light source is passive.

[0038] The voltage controller unit may be configured to measure the current level of one or more light sources to control switches of the boost converter and the buck converter. The switches may include at least a down-controllable switch and at least an up-controllable switch.

[0039] The voltage controller unit may be configured to control a buck controllable switch or a group of buck controllable switches including a first, second and / or third buck controllable switch. The buck converter may include one or more buck controllable switches. The voltage controller unit may be configured to control a boost controllable switch or a group of boost controllable switches including a first, second and / or third boost controllable switch.

[0040] The voltage controller unit may be configured to control the buck controllable switch and / or the boost controllable switch such that a measured current magnitude of a current flowing to the one or more light sources matches the current magnitude signal.

[0041] The voltage controller unit may be configured to control the current magnitude of the current flowing to the one or more light sources by applying a pulse width modulated switching signal to the buck controllable switch and / or the boost controllable switch of the buck converter and / or the boost converter, respectively. The pulse width of the pulse width modulated switching signal determines the current magnitude of the current flowing to the one or more light sources.

[0042] The intra-oral scanning device may comprise a set of one or more light sources which may be connected to the supply assembly unit.

[0043] The group of one or more light sources can be connected to another supply assembly unit, and wherein the other supply assembly unit comprises ： A boost converter configured to convert a DC voltage to a supply voltage, wherein the DC voltage is lower than the supply voltage, and a voltage controller unit configured to control the boost converter. The intraoral scanning device may include a set of white light emitting diodes (LEDs) connected to the supply assembly unit and a single infrared LED connected to the buck converter of the intraoral scanning device.

[0044] The buck converter and the boost converter may be two separate components, wherein a group of light sources and a single light source of the intra-oral scanning device share the buck converter, and the group of light sources may be further connected to the boost converter.

[0045] The boost converter and the buck converter may be combined into a main voltage converter. Thus, the group of light sources and the single light source may be connected to the main voltage converter. The group of light sources and the single light source are part of one or more light sources.

[0046] The buck converter may include an input down-terminal configured to receive a DC voltage and an output down-terminal configured to transmit a supply voltage to one or more light sources. The buck converter also includes an LC circuit connected to the output down-terminal, a first buck controllable switch connected to a first buck node of the LC circuit, and wherein the first buck controllable switch is configured to receive a DC voltage from at least one of the input buck terminals and provide an input voltage to the LC circuit through the first buck node, and wherein the voltage controller unit may be configured to control the first buck controllable switch, and wherein the LC circuit provides a supply voltage to the output buck terminal based on the input voltage. The buck converter has a simple schematic and is less expensive to produce because the solution includes a single switch instead of multiple switches.

[0047] The step-down converter may be a version of a buck converter.

[0048] Alternatively, a buck diode may be connected to the first buck node and the second buck node of the LC circuit, and the other of the input buck terminals is connected to the second buck node. The buck diode may be replaced by a second buck controllable switch controlled by the voltage controller unit. The control of the first and second buck controllable switches may be synchronous, meaning that both switches are triggered to be on or off at or about the same time.

[0049] When the step-down converter includes two switches, the step-down converter is a version of a synchronous buck converter.

[0050] The boost converter may include an input boost terminal configured to receive a DC voltage and an output boost terminal configured to transmit a supply voltage. The boost converter may include a capacitor connected to the output boost terminal, an inductor connected to a first input in the input boost terminal, and wherein the inductor may be configured to receive a DC voltage from the first input in the input boost terminal and provide a first input voltage to a first boost node. The boost converter may also include a first boost controllable switch connected to the capacitor and the inductor through a first boost node, and wherein the first boost controllable switch may be configured to receive a first input voltage through the first boost node and provide a second input voltage to the capacitor through the first boost node, and the voltage controller unit may be configured to control the first boost controllable switch, and wherein the capacitor provides a supply voltage to the output boost terminal based on the second input voltage.

[0051] The boost converter may include an input boost terminal configured to receive a DC voltage and an output boost terminal configured to transmit a supply voltage. The boost converter may include a capacitor across the output boost terminals, an inductor connected to a first input in the input boost terminals, and wherein the inductor may be configured to receive a DC voltage from the first input in the input boost terminals and provide a first input voltage to a first boost node. The boost converter may also include a first boost controllable switch connected to the inductor and the capacitor via a first boost node, and wherein the first boost controllable switch may be configured to receive a first input voltage via the first boost node and provide a second input voltage to the capacitor via the first boost node, and the voltage controller unit may be configured to control the first boost controllable switch, and wherein the capacitor provides a supply voltage to the output boost terminal based on the second input voltage.

[0052] The step-up converter may be a version of a boost converter.

[0053] A boost diode may be connected to a first boost node and a second boost node of the boost converter, and wherein the first side of the capacitor may be connected to the second boost node. The boost diode may be replaced by a second boost controllable switch controlled by the voltage controller unit. The control of the first and second boost controllable switches may be synchronous, meaning that both switches are triggered to be on or off at or about the same time.

[0054] When the boost converter includes two switches, the boost converter is a version of a synchronous boost converter.

[0055] The boost diode and the buck diode may be diodes.

[0056] The buck converter may further include a second buck controllable switch connected to the first buck controllable switch and the LC circuit via the first buck node, and wherein the first and second buck controllable switches are controlled by a voltage controller unit. Control of the first and second buck controllable switches is synchronously controlled by the voltage controller unit, which means that both switches are triggered to be on or off at the same time or approximately at the same time. The buck converter may be a synchronous buck buck converter. A synchronous buck buck converter has reduced power losses compared to a buck buck converter.

[0057] The triggering of the switch can be performed by a control signal transmitted by the voltage controller unit.

[0058] The boost converter may also include a second boost controllable switch connected to the first boost node and the second boost node of the boost converter, wherein the capacitor may be connected to the second boost node, and wherein the first and second boost controllable switches are controlled by a voltage controller unit. Control of the first and second boost controllable switches may be synchronously controlled by the voltage controller unit, meaning that the two switches are triggered to be on or off at the same time or approximately at the same time. The boost converter may be a synchronous boost converter. A synchronous boost converter has reduced power losses compared to a boost converter.

[0059] The voltage controller unit may include multiple voltage controllers, and wherein the multiple voltage controllers may include a buck controller configured to control one or more buck controllable switches of a buck converter, a boost controller configured to control one or more boost controllable switches of a boost converter, and / or a main voltage controller configured to control one or more controllable switches of a main voltage converter.

[0060] The multiple voltage controllers can be distributed to different units or located in one unit. The multiple voltage controllers can be a single unit or multiple units.

[0061] The voltage controller unit may be configured to control one or more controllable switches of the main voltage converter.

[0062] The main voltage converter may include a boost converter, wherein the first boost controllable switch may also be directly connected to the second input in the input boost terminal, and the first input in the input boost terminal may also be directly connected to the capacitor. The main voltage converter is advantageously configured to step up or step down a DC voltage to a supply voltage greater than or less than the DC voltage.

[0063] The main voltage converter includes a voltage converter configured to step down and step up a DC voltage to a supply voltage level.

[0064] The LC circuit of the buck converter includes a buck inductor and a buck capacitor connected. In the main voltage converter, the inductor of the boost converter can be a buck inductor, which means that the buck converter and the boost converter share the same inductor.

[0065] In the main voltage converter, a first one of the input boost terminals may be connected directly to the second side of the capacitor, and wherein the first boost node may be connected to the first side of the capacitor.

[0066] The main voltage converter may include a second boost controllable switch, and the second boost controllable switch may be connected to the first boost controllable switch and the capacitor. The second boost controllable switch may be connected to the first boost node and the second boost node. The second boost controllable switch may replace a boost diode. The first boost controllable switch and the second boost controllable switch are controlled by a voltage controller unit. The main voltage converter is a buck buck-boost boost converter. Compared with a solution in which two separate converters are connected in a manner in which a DC voltage is first boosted and then bucked or vice versa, the advantage of having a buck buck-boost boost converter is that complexity is reduced because fewer components are required. In addition, since components are shared between the buck converter and the boost converter, power consumption is also reduced.

[0067] The first boost controllable switch and the second boost controllable switch can be synchronously controlled by the voltage controller unit. Therefore, the power consumption is lower than without synchronous control of the switches. The main voltage converter is a synchronous buck-boost converter.

[0068] The main voltage converter may include a third boost controllable switch, and wherein the capacitor may be connected to the first output in the output boost terminal through a second boost node of the main voltage converter, and the third boost controllable switch is connected to the capacitor through a second boost node, and wherein the voltage controller unit is configured to control the first, second and third boost controllable switches. The third boost controllable switch is connected to the first output in the output boost terminal through the second boost node, thereby obtaining a faster on-off switching of the one or more light sources relative to a solution in which the on-off switching of the one or more light sources is determined by the discharge time of the capacitor. The faster on-off switching of the one or more light sources enables the main voltage converter to be used in an intraoral scanning device configured to perform real-time scanning using light sources with different wavelengths. For example, the one or more light sources may include a group of white LED light sources and a single infrared LED light source, and during scanning, the intraoral scanning device is configured to switch between the group of white LED light sources and the single infrared (IR) LED light source. The fast on-off switching allows multiple images of an object to be captured using different light sources with different wavelengths. The rapid on-off switching enables intraoral scan data to be captured using the white LED light source and other intraoral scan data to be captured using the IR LED light source, and the intraoral scan and other intraoral scan data include image data related to the same object. Without the rapid on-off switching, further and more complex image processing would be required to correlate the intraoral scan data with the other intraoral scan data.

[0069] The boost converter may further include a third boost controllable switch connected between the second boost node and the output boost terminal, and wherein the first, second and third boost controllable switches are controlled by the voltage controller unit. The control of the first, second and third boost controllable switches is synchronously controlled. The third boost controllable switch is connected to the first output in the output boost terminal through the second boost node, thereby obtaining a faster on-off switching of the one or more light sources relative to the solution of determining the on-off switching of the one or more light sources by the discharge time of the capacitor. The faster on-off switching of the one or more light sources enables the main voltage converter to be used for an intraoral scanning device configured to perform real-time scanning using light sources with different wavelengths. For example, the one or more light sources may include a group of white LED light sources and a single infrared LED light source, and during scanning, the intraoral scanning device is configured to switch between the group of white LED light sources and the single infrared (IR) LED light source. Fast on-off switching allows multiple images of an object to be captured using different light sources with different wavelengths. Fast on-off switching enables the capture of intraoral scan data using a white LED light source and other intraoral scan data using an IR LED light source, and the intraoral scan and other intraoral scan data include image data related to the same object. Without the rapid on-off switching, further and more complex image processing would be required to correlate the intraoral scan data with other intraoral scan data.

[0070] The voltage controller unit includes a plurality of voltage controllers, and wherein the plurality of voltage controllers include a main voltage controller and a boost controller, and wherein the main voltage controller may be configured to control a controllable switch of a main voltage converter, and the boost controller may be configured to control a controllable switch of a boost converter, i.e., a boost controllable switch. In this example, the intraoral scanning device may include a light source configured to receive a supply voltage from the main voltage converter, and further, a group of light sources configured to receive a supply voltage from the boost converter. The group of light sources may include a white LED light source, and the light source may include an infrared light source. The group of light sources and the light source may be part of one or more light sources.

[0071] The buck controllable switches may be first, second and third buck controllable switches which are transistors, and the boost controllable switches may be first, second and third boost controllable switches which are transistors.

[0072] The first step-down controllable switch may be a transistor or a pulse width switch, a low-frequency pulse width switch, or a high-frequency pulse width switch.

[0073] The intraoral scanning system may include an intraoral scanning device and at least a display unit configured to display 2D intraoral scanning data and / or 3D intraoral scanning data. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Various aspects of the present disclosure may be best understood from the following detailed description in conjunction with the accompanying drawings. The drawings are schematic and simplified for clarity, and they only show details to improve understanding of the claims, while other details are omitted. Throughout, the same reference numerals are used for identical or corresponding parts. The individual features of each aspect may be combined with any or all features of the other aspects. These and other aspects, features and / or technical effects will be apparent from and elucidated with reference to the drawings described below, in which:

[0075] Figure 1A and 1B Examples of an intraoral scanning device and an intraoral scanning system are shown respectively;

[0076] Figures 2A to 2E Examples of a boost converter, a buck converter, and a main voltage converter are shown;

[0077] Figure 3A and 3B Examples of boost converters and buck converters are shown;

[0078] Figure 4A and 4B Examples of boost converters and buck converters are shown;

[0079] Figure 5A and 5B An example of a main voltage converter is shown;

[0080] Fig. 6A and 6B Another example of a main voltage converter is shown;

[0081] Figure 7 An example of a supply assembly unit is shown; and

[0082] Figure 8 The normalized power spectrum as a function of LED wavelength is shown. DETAILED DESCRIPTION

[0083] The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various configurations. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be appreciated by those skilled in the art that these concepts can be practiced without these specific details. Several aspects of the apparatus, system, medium, program, and method are described by various blocks, functional units, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). Depending on the specific application, design constraints, or other reasons, these elements may be implemented using electronic hardware, computer programs, or any combination thereof.

[0084] Electronic hardware may include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described in the present disclosure. A computer program should be broadly interpreted to mean instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0085] Scanning may be performed by a dental scanning system to provide intraoral scan data, which may include an intraoral scanning device, such as a TRIOS series scanner from 3Shape A / S. The dental scanning system may include wireless capabilities provided by a wireless network unit. The scanning device may utilize a scanning principle, such as triangulation-based scanning, confocal scanning, focused scanning, ultrasonic scanning, X-ray scanning, stereoscopic vision, motion recovery structure, optical coherence tomography OCT, or any other scanning principle. In an embodiment, the scanning device operates by projecting a pattern and translating a focal plane along an optical axis of the scanning device and capturing multiple 2D images at different focal plane positions, so that each series of captured 2D images corresponding to each focal plane forms a 2D image stack and is able to obtain surface information. The acquired 2D image is also referred to herein as a raw 2D image, wherein raw in this context means that the image has not been image processed. The focal plane position is preferably moved along the optical axis of the scanning system so that the 2D images captured at multiple focal plane positions along the optical axis form the 2D image stack (also referred to herein as a sub-scan) for a given view of the object (i.e., for a given arrangement of the scanning system relative to the object). After moving the scanning device relative to the object or imaging the object in a different view, a new 2D image stack for the view can be captured. The focal plane position can be changed by at least one focusing element (e.g., moving the focusing lens). The scanning device is typically moved and angled relative to the dentition during a scanning session so that at least some of the sub-scan groups overlap at least partially, so that a digital dental 3D model can be reconstructed by stitching together overlapping sub-scans in real time and the progress of the virtual 3D model can be displayed on a display as feedback to the user. The result of the stitching is a digital 3D representation of a surface larger than that which can be captured by a single sub-scan, i.e., a digital 3D representation larger than the field of view of the 3D scanning device. Stitching, also known as registration and fusion, works by identifying overlapping areas of the 3D surface in each sub-scan and converting the sub-scans to a common coordinate system so that the overlapping areas match, ultimately generating a digital 3D model. An iterative closest point (ICP) algorithm can be used for this purpose. Another example of a scanning device is a triangulation scanner, in which a time-varying pattern is projected onto a dental object, and a sequence of images of different pattern configurations is acquired by one or more cameras at an angle relative to the projector unit.

[0086] The color texture of a dental object can be acquired by illuminating the object with different monochromatic lights (eg separate red, green and blue) or by illuminating the object with polychromatic light (eg white light).A two-dimensional image can be acquired during a white light flash.

[0087] Typically, the process of obtaining surface information of a dental object to be scanned in real time requires a scanning device to illuminate the surface and acquire a large number of two-dimensional images. Typically, a high-speed camera is used with a frame rate of 300-2000 two-dimensional frames per second, depending on the technology and the two-dimensional image resolution. The scanning device needs to process a large amount of image data to directly forward the raw image data stream to an external processing device or perform some image processing before transmitting the data to an external device or display. This process requires multiple electronic components within the scanner to operate at a high load, and therefore requires a high current demand.

[0088] The scanning device includes one or more light projectors configured to generate an illumination pattern to be projected onto a three-dimensional dental object during scanning. The (one or more) light projectors preferably include a light source, a mask having a spatial pattern, and one or more lenses, such as a collimating lens or a projection lens. The light source can be configured to generate light of a single wavelength or a combination of wavelengths (monochromatic or polychromatic). The wavelength combination can be generated by using a light source configured to generate light containing different wavelengths (e.g., white light). Alternatively, the (one or more) light projectors may include multiple light sources, such as LEDs, which individually generate light of different wavelengths (e.g., red, green, and blue), which can be combined to form light containing different wavelengths. Therefore, the light generated by the light source can be defined by a range of different wavelengths that define a wavelength of a specific color or a range of different wavelengths that define a color combination (e.g., white light). In an embodiment, the scanning device includes a light source configured to excite a fluorescent material of a tooth to obtain fluorescent data from a dental object. Such a light source can be configured to generate a narrow range of wavelengths. In another embodiment, the light from the light source is infrared (IR) light, which is able to penetrate dental tissue. The (one or more) light projectors can be DLP projectors that use a micromirror array to generate a time-varying pattern, or a diffractive optical element (DOF), or a back-illuminated mask projector, in which a light source is placed behind a mask having a spatial pattern so that the light projected onto the surface of the dental object is patterned. The back-illuminated mask projector may include a collimating lens for collimating the light from the light source, the collimating lens being placed between the light source and the mask. The mask may have a checkerboard pattern so that the generated illumination pattern is a checkerboard pattern. Alternatively, the mask may have other patterns, such as lines or dots, etc.

[0089] The scanning device preferably also includes an optical element for directing light from the light source to the surface of the dental object. The specific arrangement of the optical element depends on whether the scanning device is a focused scanning device, a scanning device using triangulation, or any other type of scanning device. The same applicant further describes a focused scanning device in EP2442720B1, which is incorporated herein in its entirety.

[0090] Using the optical elements of the scanning device, light reflected from the dental object in response to illumination of the dental object is directed toward (one or more) image sensors. The (one or more) image sensors are configured to generate multiple images based on the incoming light received from the illuminated dental object. The image sensor can be a high-speed image sensor, such as an image sensor configured to acquire images with an exposure time of less than 1 / 1000 second or a frame rate exceeding 250 frames per second (fps). As an example, the image sensor can be a rolling shutter (CCD) or a global shutter sensor (CMOS). The (one or more) image sensor can be a monochrome sensor, including a color filter array (e.g., a Bayer filter) and / or additional filters that can be configured to substantially remove one or more color components from the reflected light before converting the reflected light into an electrical signal, and retain only other unremoved components. For example, such additional filters can be used to remove a portion of the white light spectrum (e.g., a blue component) and retain only red and green components in the signal generated in response to exciting the fluorescent material of the tooth.

[0091] The network unit may be configured to connect the dental scanning system to a network including a plurality of network elements, the plurality of network elements including at least one network element configured to receive processed data. The network unit may include a wireless network unit or a wired network unit. The wireless network unit is configured to wirelessly connect the dental scanning system to a network including a plurality of network elements, the plurality of network elements including at least one network element configured to receive processed data. The wired network unit is configured to establish a wired connection between the dental scanning system and a network including a plurality of network elements, the plurality of network elements including at least one network element configured to receive processed data.

[0092] The dental scanning system preferably also includes a processor configured to generate scan data (e.g., extraoral scan data and / or intraoral scan data) by processing a two-dimensional (2D) image acquired by the scanning device. The processor may be part of the scanning device. As an example, the processor may include a field programmable gate array (FPGA) and / or an advanced RISC machine (ARM) processor located on the scanning device. The scan data includes information related to a three-dimensional dental object. The scan data may include any of the following: a 2D image, a 3D point cloud, depth data, texture data, intensity data, color data, and / or a combination thereof. For example, the scan data may include one or more point clouds, each of which includes a set of 3D points describing a three-dimensional dental object. As another example, the scan data may include images, each of which includes image data, such as image data described by image coordinates and a timestamp (x, y, t), wherein depth information may be inferred from the timestamp. The (one or more) image sensors of the scanning device may acquire multiple original 2D images of the dental object in response to irradiating the dental object using one or more light projectors. Multiple original 2D images may also be referred to herein as 2D image stacks. The 2D images can then be provided as input to a processor, which processes the 2D images to generate scan data. The processing of the 2D images may include a step of determining which part of each 2D image is in focus in order to infer / generate depth information from the image. The depth information can be used to generate a 3D point cloud, which includes a group of 3D points in space, for example, described by Cartesian coordinates (x, y, z). The 3D point cloud can be generated by the processor or other processing units. Each 2D / 3D point may also include a timestamp indicating the recording time of the 2D / 3D point, that is, which image in the 2D image stack the point originated from. The timestamp is related to the z coordinate of the 3D point, that is, the z coordinate can be inferred from the timestamp. Therefore, the output of the processor is scan data, and the scan data may include image data and / or depth data, for example, described by image coordinates and timestamps (x, y, t) or alternatively described as (x, y, z). In addition to scan data, the scanning device may be configured to transmit other types of data. Examples of data include 3D information, texture information such as infrared (IR) images, fluorescent images, reflectance color images, X-ray images, and / or combinations thereof.

[0093] FIG1 shows an intraoral scanning device 1 configured to acquire intraoral scanning data from a three-dimensional dental object 2. The intraoral scanning device 1 is a handheld device having a tip that is arranged, for example, in the mouth of a patient, and light is emitted to the dental object 2 through the tip, and light reflected from the dental object 2 is also received by the tip and forwarded to an image sensor, which then converts the reflected light into intraoral scanning data. The intraoral scanning device 1 then processes the intraoral scanning data into 2D intraoral scanning data, such as 2D image data, or 3D intraoral scanning data, such as 3D image data. In another example, the intraoral scanning device 1 processes the intraoral scanning data so that it is suitable for being wirelessly transmitted to an external device. Figure 1B An intraoral scanning system 100 is shown, which includes an intraoral scanning device 1 and an external device 200 communicating via a wireless link 150 .

[0094] Figure 2A-2E Different examples of an intraoral scanning device 1 are shown. The device 1 includes a projector unit 7, which is configured to emit light at least onto a dental object of a patient. The projector unit 7 includes one or more light sources. In one example, the one or more light sources include a plurality of white light emitting diodes (LEDs) and one or more infrared LEDs. In another example, the one or more light sources include a plurality of white light emitting diodes, one or more infrared LEDs, and one or more color LEDs. In yet another example, the one or more light sources include a plurality of white LEDs and one or more color LEDs. The color LEDs may include one or more of red, blue, green, and yellow. The device 1 also includes an image sensor 3, which is configured to acquire reflected light from at least the dental object 2. The device 1 includes a processing unit 4, which is configured to process the acquired reflected light into 2D intraoral scanning data and / or 3D intraoral scanning data. The device is powered by a battery 8, and the battery 8 is configured to supply a DC voltage. The device 1 also includes a supply component unit 10, which is configured to receive a DC voltage and provide a supply voltage to the one or more light sources. In Figure 2B In the embodiment, the supply component unit 10 includes a boost converter 6A, a buck converter 6B and / or a main voltage converter 6, and the main voltage converter 6 is a combination of the boost converter 6A and the buck converter 6B. The supply component unit 10 includes a voltage controller unit 5, which is configured to control the boost converter 6A, the buck converter 6B or the main voltage converter 6. The boost converter 6A is configured to convert a DC voltage into a supply voltage, wherein the DC voltage is lower than the supply voltage. The buck converter 6B is configured to convert a DC voltage into a supply voltage, so that the DC voltage is higher than the supply voltage. The voltage controller unit is configured to control the boost converter 6, the buck converter 6 and / or the main voltage converter 6. Figure 2CA supply assembly unit 10 is shown including a boost converter 6A, a buck converter 6B, and a voltage controller unit 5 configured to control the boost converter 6A and the buck converter 6B. Figure 2D , the projector unit 7 includes a plurality of light sources (7A, 7B). For example, the projector unit 7 includes a group of light sources 7B and a single light source 7A, and in this example, the group of light sources is connected to a boost converter 6A, and the single light source 7A is connected to a main voltage converter 6, which is a combination of a boost converter 6A and a buck converter 6B. In this example, the main voltage converter 6 is controlled by a voltage controller 5A, and the boost converter 6A is controlled by another voltage controller 5B. The voltage controllers (5A, 5B) are part of the voltage controller unit 5. Figure 2E An example is shown in which the supply assembly unit 10 includes another example of a main voltage converter 6, which is a voltage converter configured to step down and step up a voltage from a DC voltage to a supply voltage. The supply assembly unit 10 also includes a step-up converter 6A or a step-down converter 6B.

[0095] The processing unit 4 is configured to determine surface information from the acquired reflected light in real time and generate 2D intra-oral scan data and / or 3D intra-oral scan data.

[0096] The processing unit 4 is configured to determine surface information from the acquired reflected light in real time and generate a three-dimensional (3D) surface model of the dental object using the surface information.

[0097] The intraoral scanning device 1 comprises a wireless interface (not shown) configured to transmit a three-dimensional (3D) surface model in real time.

[0098] Figure 3A and 3B Examples of a buck converter 6B and a boost converter 6A are shown respectively. Figure 3A, the buck converter 6B comprises an input buck terminal (30A, 30B) configured to receive a DC voltage, an output buck terminal 39 configured to transmit a supply voltage to one or more light sources (7, 7A, 7B), an LC circuit 32 connected to the output buck terminal 39, a first buck controllable switch 33 connected to a first buck node 31 of the buck converter 6B, and wherein the first buck controllable switch 33 is configured to receive a DC voltage from at least one of the input buck terminals (30A, 30B) and provide an input voltage to the LC circuit 32 through the first buck node 31, and wherein the voltage controller unit 5 is configured to control the first buck controllable switch 33, and wherein the LC circuit 32 provides a supply voltage to the output buck terminal 39 based on the input voltage. A buck diode 34 may be optionally connected to the first buck node 31 and the second buck node 35 of the LC circuit 32, and the other of the input buck terminals (30A, 30B) is connected to the second buck node 35. The step-down converter is a buck voltage converter.

[0099] exist Figure 3B In the embodiment, the boost converter 6A includes an input boost terminal (36A, 36B) configured to receive a DC voltage, an output boost terminal 38 configured to transmit a supply voltage, a capacitor 37A connected to the output boost terminal 38, an inductor 37B connected to the first input 36A of the input boost terminals (36A, 36B), and wherein the inductor 37B is configured to receive a DC voltage from the first input 36A of the input boost terminals (36A, 36B) and provide a first input voltage to a first boost node 41. The boost converter (6, 6C) further comprises a first boost controllable switch 43 connected to the capacitor 37A and the inductor 37B via a first boost node 41, and wherein the first boost controllable switch 43 is configured to receive a first input voltage via the first boost node 41 and provide a second input voltage to the capacitor 37A via the first boost node 41, and the voltage controller unit 5 is configured to control the first boost controllable switch 43, and wherein the capacitor 37B provides a supply voltage to the output boost terminal 38 based on the second input voltage. Optionally, a boost diode 42 is connected to the first boost node 41 and the second boost node 40 of the boost converter 6A, and wherein the first side of the capacitor 37A is connected to the second boost node. The boost converter 6A is a boost voltage converter.

[0100] Figure 4A and 4B Further examples of buck converter 6B and boost converter 6A are shown respectively. Figure 4AIn the embodiment, the buck diode 34 is optionally replaced by a second buck controllable switch 44, which is connected to the first buck controllable switch 33 and the LC circuit 32 via the first buck node 31, and wherein the first and second buck controllable switches (33, 44) are controlled by the voltage controller unit 5. The buck converter 6B is a synchronous buck-converter. Figure 4B , optionally, the boost diode 42 has been replaced by a second boost controllable switch 45 connected to a first boost node 41 and a second boost node 40 of a boost converter 6A, wherein a capacitor 37A is connected to the second boost node 40, and wherein the first and second boost controllable switches (43, 45) are controlled by a voltage controller unit 5. The boost converter 6A is a synchronous boost-converter.

[0101] Figure 5A and 5B Other examples of the main voltage converter 6 are shown. The main voltage converter 6 includes a schematic diagram of a boost converter 6A, wherein the first boost controllable switch 43 is also directly connected to the second input 36B in the input boost terminal, and the first input 36A in the input boost terminal is also directly connected to the capacitor 37A. The main voltage converter 6 is a combination of a boost converter 6A and a buck converter 6B, because the main voltage converter 6 is configured to convert a DC voltage to a supply voltage, wherein the DC voltage is lower than the supply voltage, or, wherein the DC voltage is higher than the supply voltage. In addition, the first input 36A in the input boost terminal is directly connected to the second side of the capacitor 37A, and wherein the first boost node 41 is connected to the first side of the capacitor 37A. Figure 5A The main voltage converter 6 shown in FIG. 1 is a buck-boost converter. Figure 5B , the main voltage converter 6 includes a second boost controllable switch 45, and the second boost controllable switch 45 is connected to the first boost controllable switch 43 and the capacitor 37A, and wherein the first boost controllable switch 43 and the second boost controllable switch 45 are controlled by the voltage controller unit 5. In another example, the first boost controllable switch 43 and the second boost controllable switch 45 are synchronously controlled by the voltage controller unit 5.

[0102] Fig. 6ADifferent examples of a main voltage converter 6 are shown. The main voltage converter 6 comprises a third boost controllable switch 47, and wherein a capacitor 37A is connected to a first output 38A of the output boost terminals (38A, 38B) via a second boost node 40 of the main voltage converter 6, and the third boost controllable switch 47 is connected to the capacitor 37A via the second boost node 40, and wherein the voltage controller unit 6 is configured to control the first, second and third boost controllable switches (43, 45, 47).

[0103] Figure 6B Another example of a boost converter 6A is shown, which further comprises a third boost controllable switch 47 connected between the second boost node 40 and the output boost terminal 38 , and wherein the first, second and third boost controllable switches ( 43 , 45 , 47 ) are controlled by the voltage controller unit 5 .

[0104] Figure 7 An example of a supply assembly unit 10 including a main voltage converter 6 and a boost converter 6A is shown. In this example, the voltage controller unit 5 includes a plurality of voltage controllers (5A, 5B, 5C), and wherein the plurality of voltage controllers (5A, 5B, 5C) include a main voltage controller 5A and a boost controller 5B, and wherein the main voltage controller 5A is configured to control a controllable switch of the main voltage converter 6, and the boost controller 5B is configured to control a controllable switch of the boost converter 6A. The plurality of voltage controllers (5A, 5B, 5C) include a main voltage controller 5C, which is configured to forward an enable signal and a current magnitude to the associated voltage converter (6, 6A, 6B). The enable signal indicates whether one or more light sources (7, 7A, 7B) should be turned on or off, and the current magnitude signal sets the current level of the one or more light sources turned on. In another example, the boost converter 6A can be replaced by a buck converter 6B.

[0105] Typically, the voltage controller unit 5 includes a plurality of voltage controllers (5A, 5B, 5C), and wherein the plurality of voltage controllers (5A, 5B, 5C) include a buck controller 5B configured to control one or more buck controllable switches (33, 44) of a buck converter 6B. Additionally or alternatively, the plurality of voltage controllers (5A, 5B, 5C) further include a boost controller 6A configured to control one or more boost controllable switches (43, 45, 47) of the boost converter 6A.

[0106] The voltage controller unit 5 is configured to control one or more controllable switches of the main voltage converter 6 .

[0107] The switches of the voltage converter may be transistors.

[0108] The voltage controller unit 5 is configured to control the boost converter 6A and the buck converter 6B and the main voltage converter 6 through control signals including an enable signal and a current magnitude signal to one or more light sources ( 7 , 7A, 7B).

[0109] The voltage controller unit 5 is configured to measure the current magnitude level of one or more light sources (7, 7A, 7B).

[0110] The voltage controller unit 5 is configured to control the buck controllable switch 33 or a group of buck controllable switches (33, 44) including the first buck controllable switch 33 and the second buck controllable switch 44. The voltage controller unit 5 is configured to control the boost controllable switch 43 or a group of boost controllable switches (43, 45, 47) including the first boost controllable switch 43, the second boost controllable switch 45 and / or the third boost controllable switch 47.

[0111] The voltage controller unit 5 is configured to control the buck controllable switch (33, 44) and / or the boost controllable switch (43, 45, 47) so that the measured current magnitude of the current flowing to one or more light sources (7, 7A, 7B) matches the current magnitude signal.

[0112] The voltage controller unit 5 is configured to control the current magnitude of the current flowing to one or more light sources (7, 7A, 7B) by applying a pulse width modulated switching signal to the buck controllable switch (33, 44) and / or the boost controllable switch (43, 45, 47) of the buck converter 6B and / or the boost converter 6A, respectively.

[0113] The pulse width of the pulse width modulated switching signal determines the current magnitude of the current flowing to the one or more light sources (7, 7A, 7B).

[0114] Figure 8 The relationship between the normalized power spectrum of LED (7, 7A, 7B) and wavelength is shown. The color rendering index (CRI) of the solid curve is not ideal and is not suitable for intraoral scanning devices, but the CRI of the dashed line is ideal. For example, the CRI should be at least 70.

[0115] The one or more light sources (7, 7A, 7B) include at least one light emitting diode (LED) configured to emit light having a first wavelength range.

[0116] The one or more light sources (7, 7A, 7B) include a first light source 7A configured to emit light having a first wavelength range, and a second light source 7B configured to emit light having an emission maximum in a first sub-range of the first wavelength range.

[0117] The one or more light sources (7, 7A, 7B) include a second light source 7B configured to emit light having a second wavelength range, and wherein the first and second wavelength ranges include different wavelengths.

[0118] The one or more light sources (7, 7A, 7B) are configured to emit light having a first wavelength range, and wherein the first wavelength range is characterized by a color rendering index (CRI) of at least 70.

[0119] Although some embodiments have been described and shown in detail, the present disclosure is not limited to such details, but can also be implemented in other ways within the scope of the subject matter defined in the appended claims. In particular, it should be understood that other embodiments can be utilized and structural and functional modifications can be made without departing from the scope of the present invention.

[0120] Benefits, other advantages, and solutions to problems have been described herein for specific embodiments. However, benefits, advantages, solutions to problems, and any (one or more) parts / (one or more) units that may cause any benefit, advantage, or solution to appear or become more significant should not be interpreted as key, essential, or necessary features or parts / elements of any or all claims or the present invention. Therefore, the scope of the present invention is limited only by the appended claims, wherein, unless explicitly stated, references to singular parts / units / elements are not intended to mean "one and only one", but "one or more". A claim can refer to any of the preceding claims, and "any" is understood to mean "any one or more" in the preceding claims.

[0121] Structural features of the apparatus described above in the detailed description and / or in the claims can be combined with steps of the method when appropriately replaced by corresponding processes.

[0122] As used, the singular forms "a", "an", and "the" are intended to include the plural forms as well (i.e., have the meaning of "at least one"), unless expressly stated otherwise. It will also be understood that the terms "includes", "comprises", "including", and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or combinations thereof. It will also be understood that, unless expressly stated otherwise, when an element is referred to as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, but there may also be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or couplings. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Unless expressly stated otherwise, the steps of any disclosed method are not limited to the exact order described herein.

[0123] It should be understood that throughout this specification, references to "one embodiment" or "embodiment" or "aspect" or features included as "possible" mean that the specific features, structures or characteristics described in conjunction with this embodiment are included in at least one embodiment of the present disclosure. In addition, in one or more embodiments of the present disclosure, the specific features, structures or characteristics may be appropriately combined. The previous description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art and the general principles defined herein may be applied to other aspects.

[0124] The claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the claim language, wherein, unless otherwise specifically stated, elements referred to in the singular are not intended to mean "one and only one," but rather "one or more." Unless expressly stated otherwise, the term "some" refers to one or more.

[0125] project:

[0126] Item 1. An intraoral scanning device, configured to acquire intraoral scanning data from a three-dimensional dental object, the intraoral scanning device comprising:

[0127] a projector unit configured to emit at least light onto a dental object of a patient, and wherein the projector unit comprises one or more light sources;

[0128] an image sensor configured to acquire reflected light from at least the dental object;

[0129] a processing unit configured to process the acquired reflected light into 2D intra-oral scanning data and / or 3D intra-oral scanning data,

[0130] a battery configured to supply a DC voltage,

[0131] A power supply assembly for a projector unit, comprising:

[0132] a direct current (DC) voltage source having first and second supply terminals;

[0133] a controllable switch connected across first and second supply terminals of the DC voltage source;

[0134] an inductor connecting a first supply terminal of the DC voltage source to the first output terminal, a node between the one or more light sources and the controllable switch forming a second output terminal, the projector unit being connectable between the first and second output terminals; and

[0135] ○ A controller for controlling the switching of a controllable switch, the controller having a device for supplying a dual pulse width modulated switching signal to the controllable switch at two frequencies, the two frequencies including a high-frequency pulse width modulated switching signal component for controlling the magnitude of the light source current in the projector unit, and a low-frequency pulse width modulated switching signal component for controlling the duration of the light source current.

[0136] Item 2. An intraoral scanning device according to Item 1, wherein the controller further comprises an input for receiving a sensing current indicative of a light source current, and a device for modifying the low-frequency pulse width modulated switching signal component according to the sensing current.

[0137] Item 3. The intraoral scanning device according to any of the preceding items, wherein the controller comprises:

[0138] A current source for supplying a reference current;

[0139] A source for supplying a high frequency sawtooth signal;

[0140] a current mode pulse width modulator coupled to receive the sense current, the reference current and the high frequency sawtooth signal, the current mode pulse width modulator supplying the high frequency PWM switching signal component;

[0141] a source of the low frequency PWM switching signal component; and

[0142] An AND-gate having a first input for receiving the high-frequency PWM switching signal component and a second input for receiving the low-frequency PWM switching signal component, the AND-gate supplying the dual PWM switching signal.

[0143] Item 4. The intraoral scanning device according to Item 2, wherein the controller comprises:

[0144] An adder for receiving a voltage reference signal and a high-frequency sawtooth wave signal;

[0145] a comparator having an inverting input coupled to the output of the adder and a non-inverting input coupled to receive the sense current;

[0146] an RS flip-flop having a reset input coupled to the output of the comparator and a set input coupled to receive a high frequency clock signal; and

[0147] An AND gate having a first input coupled to the output of the RS flip-flop and a second input coupled to receive a low frequency PWM switching signal component, the AND gate supplying the dual PWM switching signal.

[0148] Item 5. The intraoral scanning device according to any of the preceding items, wherein the controller comprises:

[0149] an integrator coupled to receive the sense current, the integrator forming an average value of the sense current;

[0150] A low frequency sawtooth generator having a variable user control input for varying the generated low frequency sawtooth signal;

[0151] A first reference current source;

[0152] a low-frequency pulse width modulator coupled to receive the average sensed current, the low-frequency sawtooth wave signal and the first reference current, the low-frequency pulse width modulator changing a pulse width of a generated low-frequency PWM switching signal component according to the average sensed current and the low-frequency sawtooth wave signal;

[0153] a sample-and-hold circuit also coupled to receive the sensed current, the sample-and-hold circuit having a control input for receiving a low-frequency PWM switching signal component as a gate signal, the sample-and-hold circuit supplying a peak current signal of the sensed current;

[0154] A second reference current source;

[0155] High-frequency sawtooth wave generator, used to generate high-frequency sawtooth wave signal;

[0156] a high-frequency pulse width modulator, connected to receive the peak current signal, the second reference current and the high-frequency sawtooth wave signal, the high-frequency pulse width modulator changing the pulse width of the generated high-frequency PWM switching signal component according to the peak current signal and the high-frequency sawtooth wave signal; and

[0157] An AND gate having a first input for receiving a low frequency PWM switching signal component and a second input for receiving a high frequency PWM switching signal component, the AND gate supplying the dual PWM switching signal.

[0158] Item 6. The intraoral scanning device according to any of the preceding items, wherein the controller comprises:

[0159] A current source for supplying a reference current;

[0160] A source for supplying a high frequency sawtooth signal;

[0161] a current mode pulse width modulator coupled to receive the sense current, the reference current and the high frequency sawtooth signal, the current mode pulse width modulator supplying the high frequency PWM switching signal component;

[0162] a source of the low frequency PWM switching signal component; and

[0163] An AND gate having a first input for receiving the high frequency PWM switching signal component and a second input for receiving the low frequency PWM switching signal component, the AND gate supplying the dual PWM switching signal.

[0164] Item 7. An intraoral scanning device according to Item 6, wherein when the dual pulse width modulated switching signal is applied to the controllable switch, the change in the duty cycle of the controllable switch is substantially instantaneous.

[0165] Item 8. The intraoral scanning device according to any of the preceding items, wherein the controller comprises:

[0166] An adder for receiving a voltage reference signal and a high-frequency sawtooth wave signal;

[0167] a comparator having an inverting input coupled to the output of the adder and a non-inverting input coupled to receive the sense current;

[0168] an RS flip-flop having a reset input coupled to the output of the comparator and a set input coupled to receive a high frequency clock signal; and

[0169] An AND gate having a first input coupled to the output of the RS flip-flop and a second input coupled to receive a low frequency PWM switching signal component, the AND gate supplying the dual PWM switching signal.

[0170] Item 9. An intraoral scanning device according to Item 8, wherein when the dual pulse width modulated switching signal is applied to the controllable switch, the change in the duty cycle of the controllable switch is substantially instantaneous.

[0171] Item 10. The intraoral scanning device according to any of the preceding items, wherein the controller comprises:

[0172] an integrator coupled to receive the sense current, the integrator forming an average value of the sense current;

[0173] A low frequency sawtooth generator having a variable user control input for varying the generated low frequency sawtooth signal;

[0174] A first reference current source;

[0175] a low-frequency pulse width modulator coupled to receive the average sensed current, the low-frequency sawtooth wave signal and the first reference current, the low-frequency pulse width modulator changing a pulse width of a generated low-frequency PWM switching signal component according to the average sensed current and the low-frequency sawtooth wave signal;

[0176] a sample-and-hold circuit also coupled to receive the sensed current, the sample-and-hold circuit having a control input for receiving a low-frequency PWM switching signal component as a gating signal, the sample-and-hold circuit supplying a peak current signal of the sensed current;

[0177] A second reference current source;

[0178] High-frequency sawtooth wave generator, used to generate high-frequency sawtooth wave signal;

[0179] a high-frequency pulse width modulator, connected to receive the peak current signal, the second reference current and the high-frequency sawtooth wave signal, the high-frequency pulse width modulator changing the pulse width of the generated high-frequency PWM switching signal component according to the peak current signal and the high-frequency sawtooth wave signal; and

[0180] An AND gate having a first input for receiving a low frequency PWM switching signal component and a second input for receiving a high frequency PWM switching signal component, the AND gate supplying the dual PWM switching signal.

[0181] Item 11. An intraoral scanning device according to Item 10, wherein when the dual pulse width modulated switching signal is applied to the controllable switch, the change in the duty cycle of the controllable switch is substantially instantaneous.

[0182] Item 12. An intraoral scanning device according to any of the preceding items, wherein the voltage controller unit includes multiple voltage controllers, and wherein the multiple voltage controllers include a main voltage controller and a boost controller, and wherein the main voltage controller is configured to control a controllable switch of a main voltage converter, and the boost controller is configured to control a controllable switch of the boost converter.

[0183] Item 13. An intraoral scanning device according to any of the preceding items, wherein the step-down controllable switches including the first, second and third step-down controllable switches are transistors, and the step-up controllable switches including the first, second and third step-up controllable switches are transistors.

[0184] Item 14. An intraoral scanning device according to any of the preceding items, wherein the voltage controller unit is configured to control a boost converter, a buck converter and / or a main voltage converter via a control signal including an enable signal and a current magnitude signal to one or more light sources.

[0185] Item 15. The intraoral scanning device according to any of the preceding items, wherein the voltage controller unit is configured to measure the current level of one or more light sources.

[0186] Item 16. An intraoral scanning device according to any one of Items 14 and 15, wherein the voltage controller unit is configured to control a step-down controllable switch or a group of step-down controllable switches including a first, a second and / or a third step-down controllable switch, and / or the voltage controller unit is configured to control a step-up controllable switch or a group of step-up controllable switches including a first, a second and / or a third step-up controllable switch.

[0187] Item 17. An intraoral scanning device according to Items 15 and 16, wherein the voltage controller unit is configured to control the step-down controllable switch and / or the step-up controllable switch so that the measured current magnitude of the current flowing to one or more light sources matches the current magnitude signal.

[0188] Item 18. An intraoral scanning device according to any one of Items 14 to 17, wherein the voltage controller unit is configured to control the current magnitude of the current flowing to one or more light sources by applying a pulse width modulated switching signal to a buck controllable switch and / or a boost controllable switch of a buck converter and / or a boost converter, respectively.

[0189] Item 19. An intraoral scanning device according to Item 18, wherein the pulse width of the pulse width modulated switching signal determines the current magnitude of the current flowing to the one or more light sources.

[0190] Item 20. An intraoral scanning device according to any of the preceding items, wherein the one or more light sources include at least one light emitting diode (LED) configured to emit light having a first wavelength range.

[0191] Item 21. An intraoral scanning device according to Item 20, wherein the one or more light sources include a second light source configured to emit light having an emission maximum within a first sub-range of the first wavelength range.

[0192] Item 22. An intraoral scanning device according to any one of Items 20 and 21, wherein the one or more light sources include a second light source adapted to emit light having an emission maximum within a first sub-range of the first wavelength range.

[0193] Item 23. An intraoral scanning device according to any one of Items 20 to 22, wherein the one or more light sources include a second light source configured to emit light having a second wavelength range, and wherein the first and second wavelength ranges include different wavelengths.

[0194] Item 24. In the intraoral scanning device according to any of the preceding items, the one or more light sources are configured to emit light having a first wavelength range, and wherein the first wavelength range is characterized by having a color rendering index (CRI) of at least 70.

[0195] Item 25. The intraoral scanning device according to any of the preceding items, wherein the processing unit is configured to determine surface information from the acquired reflected light in real time and generate 2D intraoral scanning data and / or 3D intraoral scanning data.

[0196] Item 26. The intraoral scanning device according to any of the preceding items, wherein the processing unit is configured to determine surface information from the acquired reflected light in real time and generate a three-dimensional (3D) surface model of the dental object using the surface information.

[0197] Item 27. The intraoral scanning device of Item 36, comprising a wireless interface configured to transmit a three-dimensional (3D) surface model in real time.

[0198] Item 28. An intraoral scanning system comprising:

[0199] An intraoral scanning device according to any of the preceding items, and

[0200] A display unit configured to display 2D intra-oral scan data and / or 3D intra-oral scan data.

Claims

1. An intraoral scanning device, configured to acquire intraoral scanning data from a three-dimensional dental object, the intraoral scanning device comprising: a projector unit configured to emit light at least onto a dental object of the patient based on a scanning sequence, and wherein the projector unit comprises one or more light sources and the scanning sequence comprises a sequence of emitted light of the one or more light sources; an image sensor configured to acquire reflected light from at least the dental object; a processing unit configured to process the acquired reflected light into 2D intra-oral scanning data and / or 3D intra-oral scanning data, a battery unit configured to supply a DC voltage, and a supply assembly unit, the supply assembly unit being configured to receive the DC voltage and provide a supply voltage to the one or more light sources, the supply assembly unit comprising: a boost converter configured to convert the DC voltage to a supply voltage, wherein the DC voltage is lower than the supply voltage, a buck converter configured to convert the DC voltage to a supply voltage such that the DC voltage is higher than the supply voltage, and o A voltage controller unit configured to control the boost converter and the buck converter based on the scan sequence.

2. The intraoral scanning device according to claim 1, wherein: The scanning sequence includes an on-off switching timing of each of the one or more light sources, and wherein the on-off switching timing determines when each of the one or more light sources is turned on and off during the scanning sequence.

3. An intraoral scanning device according to any one of the preceding claims, wherein: The scanning sequence includes a current level when each of the one or more light sources is turned on, and / or a current level when each of the one or more light sources is turned off.

4. An intraoral scanning device according to any one of the preceding claims, comprising a group of said one or more light sources, and wherein: The group of light sources is connected to the supply assembly unit, and wherein the group of light sources of the one or more light sources is connected to another supply assembly unit, and wherein the another supply assembly unit comprises: a boost converter configured to convert the DC voltage to a supply voltage, wherein the DC voltage is lower than the supply voltage, and • A voltage controller unit configured to control the boost converter.

5. An intraoral scanning device according to any one of the preceding claims, wherein: The boost converter and the buck converter are combined into a main voltage converter.

6. An intraoral scanning device according to any one of the preceding claims, wherein: The buck converter comprises: an input buck terminal configured to receive the DC voltage, an output step-down terminal configured to transmit the supply voltage to the one or more light sources, · An LC circuit connected to the output buck terminal, a first buck controllable switch connected to a first buck node of the buck converter, and wherein the first buck controllable switch is configured to receive the DC voltage from at least one of the input buck terminals and to provide an input voltage to the LC circuit via the first buck node, and wherein the voltage controller unit is configured to control the first buck controllable switch, and The LC circuit provides the supply voltage to the output step-down terminal based on the input voltage.

7. An intraoral scanning device according to any one of the preceding claims, wherein: The boost converter comprises: an input boost terminal configured to receive the DC voltage, an output boost terminal configured to transmit the supply voltage, · A capacitor connected to the output boost terminal, an inductor connected to a first one of the input boost terminals, and wherein the inductor is configured to receive the DC voltage from the first one of the input boost terminals and to provide a first input voltage to a first boost node, and a first boost controllable switch connected to the capacitor and the inductor via the first boost node, and wherein the first boost controllable switch is configured to receive the first input voltage via the first boost node and to provide a second input voltage to the capacitor via the first boost node, and the voltage controller unit is configured to control the first boost controllable switch, and The capacitor provides the supply voltage to the output boost terminal based on the second input voltage.

8. The intraoral scanning device according to claim 6, wherein: The buck converter further comprises a second buck controllable switch connected to the first buck controllable switch and the LC circuit through the first buck node, and wherein the first buck controllable switch and the second buck controllable switch are controlled by the voltage controller unit.

9. The intraoral scanning device according to claim 7, wherein: The boost converter further comprises a second boost controllable switch connected to the first boost node and a second boost node of the boost converter, wherein the capacitor is connected to the second boost node, and wherein the first boost controllable switch and the second boost controllable switch are controlled by the voltage controller unit.

10. The intraoral scanning device according to any one of claims 1 to 9 or claim 5, wherein: The voltage controller unit comprises a plurality of voltage controllers, and wherein the plurality of voltage controllers comprises: a buck controller configured to control one or more buck controllable switches of the buck converter, a boost controller configured to control one or more boost controllable switches of the boost converter, and / or - a main voltage controller configured to control one or more controllable switches of the main voltage converter.

11. The intraoral scanning device according to claim 5, wherein: The voltage controller unit is configured to control one or more controllable switches of the main voltage converter.

12. The intraoral scanning device according to claims 5 and 7, wherein: The main voltage converter comprises the boost converter, wherein the first boost controllable switch is also directly connected to a second one of the input boost terminals, and the first one of the input boost terminals is also directly connected to the capacitor.

13. The intraoral scanning device according to claim 12, wherein: A first one of the input boost terminals is directly connected to a second side of the capacitor, and wherein the first boost node is connected to a first side of the capacitor.

14. The intraoral scanning device according to any one of claims 12 and 13, wherein: The main voltage converter includes a second boost controllable switch, and the second boost controllable switch is connected to the first boost controllable switch and the capacitor, and wherein the first boost controllable switch and the second boost controllable switch are controlled by the voltage controller unit.

15. The intraoral scanning device according to claim 14, wherein: The main voltage converter comprises a third boost controllable switch, and wherein the capacitor is connected to a first output in the output boost terminal via a second boost node of the main voltage converter, and the third boost controllable switch is connected to the capacitor via the second boost node, and wherein the voltage controller unit is configured to control the first boost controllable switch, the second boost controllable switch and the third boost controllable switch.

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