A calibration device and calibration system for an intraoral scanner

Abstract

The application discloses a calibration device and a calibration system for an intraoral scanner, and belongs to the technical field of three-dimensional scanning, and comprises a calibration plate and a support structure which are configured to rotate the calibration plate at a preset angle change under manual rotation or external driving to cooperate with a continuous automatic calibration process, and an operator is not required to perform additional confirmation in a software interface. The calibration plate is rotated around a rotation shaft, the posture change required for calibration is ensured, and the structure of the calibration device is significantly simplified. A mark point is arranged on the calibration plate, and the spatial distribution change of the mark point is analyzed based on scanning data, automatic judgment of the rotation direction and the rotation angle of the calibration plate is realized, and the dependence on the experience of the operator is reduced. In the case that the calibration plate is manually rotated, the calibration process is automatically guided in a software mode, an operator is not required to perform additional confirmation operation in the software interface, and the calibration efficiency and operation consistency are improved.

Description

Technical Field

[0001] This invention belongs to the field of three-dimensional scanning technology, specifically referring to a calibration device and calibration system for an intraoral scanner. Background Technology

[0002] With the continuous development of 3D scanning technology, its application in the field of digital oral healthcare is becoming increasingly widespread. As an important device for acquiring three-dimensional data of patients' oral cavity, intraoral scanners have been widely used in clinical scenarios such as denture design, orthodontic analysis, and implant restoration. In order to ensure that the three-dimensional data acquired by intraoral scanners have sufficient accuracy and consistency in actual use, it is usually necessary to calibrate the intraoral scanner before leaving the factory or before use. Existing calibration schemes mainly include fully automatic calibration devices and manual calibration devices.

[0003] Fully automatic calibration devices typically use actuators such as motors and turntables to automatically switch the calibration plate between multiple angles and positions. Although this can reduce human error, their complex structure, large size, and high manufacturing cost make them unsuitable for widespread application in dental medical equipment.

[0004] Although manual calibration schemes are relatively simple in structure, they usually require the operator to manually confirm or trigger the next calibration process through the software interface after each adjustment of the calibration plate position. The operation process is cumbersome and prone to omissions or errors in the sequence of steps, which affects calibration efficiency and consistency. To address this, a calibration device and calibration system for intraoral scanners are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a calibration device and calibration system for an intraoral scanner to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a calibration device and a calibration system for an intraoral scanner, wherein the calibration device includes a calibration plate and a support structure, and the calibration system includes an intraoral scanner, the above-mentioned calibration device, and a calibration processing module.

[0007] The calibration plate is provided with multiple marker points, which are distributed in a pre-defined known pattern. The marker points are dot-shaped markers, circular markers, coded dot matrices, or graphic markers with unique identification features. The distribution pattern and identification features of the marker points can support the automatic determination of the rotation state of the calibration plate.

[0008] The support structure supports the calibration plate and limits the calibration plate to rotate around a fixed rotation axis. The rotation axis is inclined relative to the surface of the calibration plate, with an inclination angle in the range of 10° to 75°, and the position of the fixed rotation axis is fixed relative to the support structure. The calibration plate and the support structure are configured to rotate the calibration plate by a preset angle under manual rotation or external drive to cooperate with the continuous automatic calibration process without the need for additional confirmation by the operator in the software interface.

[0009] The intraoral scanner is used to scan the calibration plate to obtain scan data; the calibration processing module is used to obtain the scan data output by the intraoral scanner and identify the marker points on the calibration plate based on the scan data.

[0010] The calibration processing module determines the rotation direction and angle of the calibration plate based on the known distribution of the marker points and the spatial distribution changes of the marker points at different scanning times. When the rotation angle meets the preset calibration posture conditions, it automatically enters the next calibration stage, realizing continuous automatic calibration without the need for manual confirmation.

[0011] Furthermore, the calibration processing module includes a marker point recognition module and a guidance prompt module that communicate with each other; the marker point recognition module is used to identify marker points from the scan data and extract the spatial distribution location information of the marker points; the guidance prompt module is used to output prompt information indicating the rotation state of the calibration plate based on the spatial distribution changes of the marker points, the prompt information including the rotation direction, rotation amplitude, or whether the calibration plate has reached a preset angle.

[0012] Furthermore, the calibration processing module determines the rotation direction of the calibration plate by comparing the relative positional change directions of the marker points in adjacent scan data.

[0013] Furthermore, the calibration processing module calculates the rotation angle of the calibration plate based on the rotation displacement of the marker point in the scan data, or determines whether the rotation angle falls within a preset angle range that matches the preset calibration posture conditions.

[0014] Furthermore, when it is determined that the rotation angle does not meet the preset calibration posture conditions, the guidance prompt module outputs prompt information to guide the calibration board rotation, enabling the operator to quickly adjust the calibration board to the target position to support the continuous automatic calibration process.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. By limiting the calibration plate to rotate around the rotation axis, this invention significantly simplifies the structure of the calibration device and reduces manufacturing costs and assembly difficulty while ensuring the required attitude changes for calibration.

[0017] 2. This invention achieves automatic judgment of the rotation direction and angle of the calibration plate by setting marker points on the calibration plate and analyzing the spatial distribution changes of the marker points based on scanning data, thereby reducing reliance on the operator's experience.

[0018] 3. This invention automatically guides the calibration process through software when the calibration plate is rotated manually, eliminating the need for operators to perform additional confirmation operations in the software interface, thereby improving calibration efficiency and operational consistency.

[0019] 4. This invention has a simple structure and strong adaptability, which avoids the high cost of fully automatic calibration devices and solves the cumbersome operation problem of manual calibration devices. It has good engineering practical value and promotion prospects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the calibration system.

[0021] Figure 2 This is a schematic cross-sectional view of the calibration device.

[0022] Figure 3 This is a schematic diagram of the calibration plate and its supporting structure.

[0023] Figure 4 This is a schematic cross-sectional view of the calibration device.

[0024] Figure 5 This is a schematic diagram of the calibration system's workflow.

[0025] Legend: 1. Intraoral scanner; 2. Calibration plate; 22. Marker point; 3. Support structure; 4. Preset point. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example

[0028] Please see Figures 1-5As shown, the present invention provides a technical solution including an intraoral scanner 1, a calibration device, and a calibration processing module. The calibration device consists of a calibration plate 2 and a support structure 3. The calibration processing module includes a marker recognition module and a guidance prompt module that communicate with each other. The components work together to realize a continuous automatic calibration process without the need for manual confirmation.

[0029] The calibration plate 2 is provided with a plurality of marker points 22. The plurality of marker points 22 are in a pre-set known distribution pattern on the calibration plate 2. In this embodiment, they are preferably evenly distributed in a 15×15 matrix with a distribution spacing of 2mm, which ensures recognition accuracy and facilitates the calculation of rotational displacement. The marker points 22 are circular markers with a diameter of 2mm and are coated with a high-contrast coating (black coating, white base) to give them unique identifiable features. This enables them to stably support the automatic judgment of the rotational state of the calibration plate 2 and avoid recognition deviations during the scanning process.

[0030] The support structure 3 is used to stably support the calibration plate 2 and strictly limit the calibration plate 2 to rotate only around a fixed rotation axis. The position of the fixed rotation axis is fixed relative to the support structure 3 and does not shift with the rotation of the calibration plate 2. The rotation axis is inclined relative to the surface of the calibration plate 2, and the inclination angle is selected as 45° (within the preset range of 10°~75°). This angle can meet the posture change requirements of the intraoral scanner 1 for calibration and make the spatial distribution changes of the marker points 22 easier to be scanned and identified, thus balancing calibration accuracy and ease of operation.

[0031] The calibration plate 2 and the support structure 3 are configured to rotate the calibration plate 2 at a preset angle under manual rotation or external drive. In this embodiment, manual rotation is preferred. The support structure 3 is equipped with an anti-slip rotation knob, which makes it easy for the operator to accurately control the rotation amplitude. No additional confirmation operation is required from the operator in the calibration software interface. It can directly cooperate with the calibration processing module to achieve continuous calibration.

[0032] The scanning lens of the intraoral scanner 1 is aligned with the effective scanning area (including all marker points 22) of the calibration plate 2 to perform real-time continuous scanning of the calibration plate 2, acquire scanning data including marker points 22, and transmit the scanning data to the calibration processing module in real time.

[0033] The calibration processing module establishes a communication connection with the intraoral scanner 1 to acquire the scanning data output by the intraoral scanner 1. The marker point recognition module is used to quickly identify marker points 22 from the scanning data, extract the spatial distribution location information (three-dimensional coordinates) of each marker point 22, and transmit the extracted coordinate information to the guidance prompt module in real time. The guidance prompt module is used to output prompt information to indicate the rotation status of the calibration plate 2 based on the spatial distribution changes of the marker points 22.

[0034] In this embodiment, the prompt information adopts a software interface visual prompt method, specifically including: rotation direction prompt (clockwise / counterclockwise red arrow), rotation range prompt (text prompts such as "need to rotate to position X°" or "already rotated to position X°"), and status prompts for whether the preset angle has been reached (green checkmark / red cross). The operator can quickly and accurately adjust the rotation state of the calibration plate 2 according to the prompt information without relying on operating experience.

[0035] The core working logic of the calibration processing module is as follows: First, based on the preset known matrix distribution of the marker point 22, a reference coordinate system is established (with the fixed rotation axis as the origin); then, combined with the spatial distribution changes of the marker point 22 at different scanning times, the rotation direction and rotation angle of the calibration plate 2 are determined.

[0036] The rotation direction is determined by comparing the relative position change direction of each marker point 22 in two adjacent frames of scan data, and combining the orientation of the reference coordinate system to determine the rotation direction (clockwise or counterclockwise) of the calibration plate 2. For example, when the marker point 22 on the right side of the matrix shifts upward relative to the marker point 22 on the left side in adjacent scan data, it is determined to be a clockwise rotation.

[0037] The rotation angle is determined as follows: the rotation angle of the calibration plate 2 is calculated based on the rotation displacement of the marker point 22 in the scan data. Specifically, the calculation method is as follows: with the fixed rotation axis as the origin, the change in polar coordinate angle of each marker point 22 in adjacent scan data is calculated, and the average value of the angle changes of all marker points 22 is taken as the actual rotation angle of the calibration plate 2. At the same time, multiple preset points are set, preferably nine in this embodiment, and the points are marked as the corresponding rotation angles. The calibration processing module synchronously determines whether the actual rotation angle falls into a point that matches the calibration posture conditions of each preset point.

[0038] When the calibration processing module determines that the actual rotation angle of the calibration plate 2 meets the calibration posture conditions of a certain preset point, it automatically enters the next calibration stage without manual triggering. When the calibration processing module determines that the actual rotation angle does not meet the preset calibration posture conditions, the guidance prompt module immediately outputs prompt information to guide the rotation of the calibration plate 2. For example, when the calibration begins and the actual rotation angle is 80° (not reaching the 0°±2° range), the software interface displays a clockwise red arrow and prompts "Need to rotate to position 1", i.e., the initial position. The operator rotates the knob of the support structure 3 according to the prompt, driving the calibration plate 2 to rotate. The intraoral scanner 1 continues to scan, and the calibration processing module updates the judgment in real time, forming a closed-loop feedback until the calibration plate 2 rotates to the target position (within the preset angle range).

[0039] In this embodiment, the preset point 4 is the target position when the calibration plate 2 rotates to each preset angle range. When the calibration plate 2 rotates to the preset point 4, the guidance prompt module outputs a green checkmark status prompt, and the calibration processing module automatically enters the next calibration stage. After completing the calibration of all calibration postures in sequence, the module outputs the prompt message "calibration completed". The whole process does not require manual confirmation, making the operation convenient and efficient, and the calibration consistency error is ≤0.02mm.

[0040] Through the above specific implementation methods, the technical advantages of the present invention can be clearly demonstrated: the structure of the calibration device is simplified, eliminating the need for complex actuators such as motors and turntables, thus greatly reducing manufacturing costs; through the preset known distribution of marker points and precise rotation axis design, accurate identification and guidance of the rotation state are achieved; manual rotation combined with automatic software propulsion not only solves the cumbersome operation problem of manual calibration but also avoids the high cost defect of fully automatic calibration.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their likenesses.

[0042] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A calibration device for an intraoral scanner, characterized in that: include; A calibration board, wherein multiple marker points are provided on the calibration board, and the multiple marker points are in a pre-defined known distribution pattern on the calibration board; A support structure is provided for supporting the calibration plate and limiting the calibration plate to rotate around a fixed rotation axis, wherein the rotation axis is inclined relative to the surface of the calibration plate, the inclination angle is in the range of 10° to 75°, and the position of the fixed rotation axis is fixed relative to the support structure. The calibration plate and support structure are configured to rotate at a preset angle under manual rotation or external drive, in order to cooperate with the continuous automatic calibration process without the need for additional confirmation by the operator in the software interface.

2. The calibration device for an intraoral scanner according to claim 1, characterized in that: The markers are dot-shaped markers, circular markers, coded dot matrices, or graphic markers with unique identification features, and the distribution and identification features of the markers can support the automatic determination of the calibration plate's rotation state.

3. A calibration system for an intraoral scanner, characterized in that, include: An intraoral scanner is used to scan the calibration plate to obtain scan data; The calibration processing module is used to acquire the scanning data output by the intraoral scanner and identify the marker points on the calibration plate based on the scanning data. The calibration processing module determines the rotation direction and angle of the calibration plate based on the known distribution of the marker points and the spatial distribution changes of the marker points at different scanning times. When the rotation angle meets the preset calibration posture conditions, it automatically enters the next calibration stage, realizing continuous automatic calibration without the need for manual confirmation.

4. A calibration system for an intraoral scanner according to claim 3, characterized in that: The calibration processing module includes a marker point recognition module and a guidance prompt module that communicate with each other; The marker recognition module is used to identify markers from the scanned data and extract the spatial distribution location information of the markers; The guidance and prompting module is used to output prompting information to indicate the rotation status of the calibration plate based on the spatial distribution changes of the marker points. The prompting information includes the rotation direction, rotation amplitude, or whether the calibration plate has reached a preset angle.

5. A calibration system for an intraoral scanner according to claim 4, characterized in that: The calibration processing module determines the rotation direction of the calibration plate by comparing the relative positional changes of the marker points in adjacent scan data.

6. A calibration system for an intraoral scanner according to claim 4, characterized in that: The calibration processing module calculates the rotation angle of the calibration plate based on the rotation displacement of the marker point in the scan data, or determines whether the rotation angle falls within a preset angle range that matches the preset calibration posture conditions.

7. A calibration system for an intraoral scanner according to claim 4, characterized in that: When it is determined that the rotation angle does not meet the preset calibration posture conditions, the guidance prompt module outputs prompt information to guide the rotation of the calibration board, so that the operator can quickly adjust the calibration board to the target position to support the continuous automatic calibration process.

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