Oral cavity scanner control method, oral cavity scanner and storage medium

Abstract

The invention relates to the technical field of medical instruments for oral cavities, in particular to a control method of an oral cavity scanner, the oral cavity scanner and a storage medium, and can be applied to examination of oral cavity diseases and oral cavity treatment. The oral cavity scanner comprises a grasping part for an operator to grasp and an extension part which is detachably installed on the grasping part and used for entering the oral cavity of a subject, the extension part comprises a reflecting mirror, and the grasping part comprises a light projector used for projecting light to the side of the reflecting mirror and a camera used for obtaining an image of the side of the reflecting mirror. The control method comprises the steps that the light projector projects structured light with a first projection area, a first image is obtained through the camera, and all the reflectors fall into the first projection area; determining the position and size information of the reflector based on the first image; based on the position and size information, the light projector projects planar light at a second projection area, and a second image is acquired using the camera, where the second projection area falls entirely within the mirror.

Description

Technical Field

[0001] The present application relates to the technical field of oral scanners, and in particular, to a control method for an oral scanner, an oral scanner, and a storage medium, which can be used for the examination of oral diseases. Background Art

[0002] An oral scanner is a medical device used to digitize the oral cavity structure. By inserting it into the oral cavity of the subject and using optical technology, it can obtain three-dimensional data of oral internal tissues (such as the upper jaw, lower jaw, tongue, gums, etc.), and can be widely used in the examination of oral diseases (such as oral deformities) and oral treatment and other fields.

[0003] An oral scanner generally includes an opening for light to enter and exit, a mirror disposed at the opening, a light projector that projects light toward the mirror side, and an imager for obtaining an image on the mirror side. During operation, the opening and the mirror of the oral scanner are placed in the oral cavity of the subject. The light projector projects light toward the mirror side. The light is reflected by the mirror and then exits from the opening of the extension part to the inner wall of the oral cavity. Then, the light is reflected by the inner wall of the oral cavity and returns to the mirror through the opening, and then at least part of the light enters the imager after being reflected by the mirror, so that the imager obtains an image representing the oral cavity shape.

[0004] The larger the radial dimension of the mirror, the larger the range of a single image frame that the imager can obtain, which is more conducive to the oral scanner obtaining high-quality oral images. Therefore, according to the difference in the oral cavity size of the subject, a mirror with an appropriate and as large size as possible can be correspondingly configured to take into account the experience of the subject and high imaging quality.

[0005] Based on this, an oral scanner proposed by the related art includes a gripping portion for the operator to hold and an extension portion detachably mounted on the gripping portion and for entering the oral cavity of the subject. A light projector and a camera are arranged in the gripping portion, and a reflector is arranged in the extension portion. Moreover, the extension portion has multiple size models, and reflectors of different sizes are provided for different size models of the extension portion. Thus, when facing a subject with a large oral cavity, the extension portion of the large size model is mounted on the gripping portion; when facing a subject with a small oral cavity, the extension portion of the small size model is mounted on the gripping portion. Since the reflectors of different sizes have different sizes, if the light projector in the gripping portion projects light onto the reflectors of different sizes in different extension portions with a unified projection area, the following problems will occur: if the projection area size is relatively small, the areas of different sized reflectors irradiated by the light projector are the same. Therefore, even if the extension portion of the large size is replaced, the imaging quality will not be improved, thus losing the meaning of configuring extension portions of multiple size models; if the projection area is relatively large, then part of the light will irradiate the peripheral area of the reflector in the extension portion, that is, part of the light will irradiate the inner wall of the extension portion housing, and part of the light irradiated on this inner wall will be reflected into the camera. These lights irradiated on the inner wall of the extension portion housing and reflected into the camera will affect the imaging quality of the oral cavity by the camera, because such lights do not act on the inner wall of the oral cavity as the target scanning object and cause interference to the imaging clarity of the target scanning object. Therefore, it is necessary to remove them. Summary of the Invention

[0006] In view of this, the present application provides a control method for an oral scanner, an oral scanner, and a storage medium.

[0007] In a first aspect, a control method for an oral scanner is proposed. The oral scanner includes a gripping portion for the operator to hold, an extension portion detachably mounted on the gripping portion and for entering the oral cavity of the subject. The extension portion includes a reflector, and the gripping portion includes a light projector for projecting light toward the reflector side and a camera for acquiring an image of the reflector side. The method includes:

[0008] Causing the light projector to project structured light with a first projection area, and acquiring a first image by using the camera, wherein the entire reflector falls within the first projection area;

[0009] Based on the first image, determining the position and size information of the reflector;

[0010] Based on the position and size information, causing the light projector to project planar light with a second projection area, and acquiring a second image by using the camera, wherein the second projection area entirely falls within the reflector.

[0011] In some possible embodiments, the structured light includes:

[0012] A plurality of first strip-shaped lights, which, when observed along the optical axis direction of the light projector, are arranged at equal intervals in a first direction and extend in a second direction, wherein the first direction is perpendicular to the second direction;

[0013] A plurality of second strip-shaped lights, which, when observed along the optical axis direction of the light projector, are arranged at equal intervals in the second direction and extend in the first direction, and each of the second strip-shaped lights intersects with the plurality of first strip-shaped lights.

[0014] In some possible embodiments, the structured light includes a plurality of dot lights, which, when observed along the optical axis direction of the light projector, are arranged at intervals from each other in a two-dimensional matrix shape.

[0015] In some possible embodiments, determining the position and size information of the mirror based on the first image includes:

[0016] Determining, from the first image, a non-mirror area corresponding to the shape of the structured light and a mirror area not corresponding to the shape of the structured light, wherein the non-mirror area surrounds the mirror area in the entire circumference;

[0017] Determining the position and size information of the mirror according to the number and position of the structured light units corresponding to the non-mirror area.

[0018] In some possible embodiments, before the light projector projects a planar light with a second projection area, the method includes: determining the second projection area as an area smaller than the determined size information of the mirror.

[0019] In some possible embodiments, determining the position and size information of the mirror according to the number and position of the structural units corresponding to the non-mirror area includes:

[0020] Determining the position of the mirror according to the position of the structural units corresponding to the non-mirror area;

[0021] Determining the difference between the total number of the structured light units in the structured light and the number of the structural units corresponding to the non-mirror area as the number of the structured light units occupied by the mirror area;

[0022] Determining the projected area of the mirror along the optical axis direction of the light projector according to the number of the structured light units occupied by the mirror area.

[0023] Determining the second projection area as an area smaller than the determined size information of the mirror includes: determining the second projection area as an area smaller than the projection area and entirely falling within the projection area.

[0024] In some possible implementation manners, before the light projector projects planar light with a second projection area, the method includes:

[0025] Determining the second projection area according to the closed outer boundary defined by a plurality of target structured light units, wherein the boundary of the second projection area coincides with the closed outer boundary, and the plurality of target structured light units are the structured light units remaining after removing the structured light units on the peripheral side from the structured light units occupied by the determined mirror area.

[0026] In some possible implementation manners, the mirror has a black body disposed on the entire periphery thereof, and the method further includes:

[0027] Causing the light projector to project second planar light with a third projection area, and acquiring a third image by using the camera, wherein the mirror entirely falls within the third projection area;

[0028] Determining the second position and size information of the mirror based on the closed black circular pattern in the third image, wherein the black circular pattern corresponds to the black body and does not define the boundary of the third image;

[0029] Based on the second position and size information, causing the light projector to project third planar light with a fourth projection area, and acquiring a fourth image by using the camera, wherein the third planar light entirely falls within the mirror.

[0030] In a second aspect, an oral scanner is provided, including:

[0031] An extension part for entering the oral cavity of a subject and including a mirror;

[0032] A grasping part for an operator to grasp and detachably installed with the extension part, including a light projector for projecting light toward the mirror side and a camera for acquiring an image of the mirror side;

[0033] A control device electrically connected to the light projector and the camera, and configured to execute the method as described in the first aspect.

[0034] In a third aspect, a computer storage medium is provided, characterized by including:

[0035] A memory,

[0036] A processor connected to the memory, and

[0037] Program instructions stored in the memory and executable by the processor;

[0038] Wherein, when the processor executes the program instructions, the method described in the first aspect is implemented.

[0039] According to the control method of the oral scanner provided by the present application, this method can automatically adjust the projection area size of the light projector according to the size of the mirror currently installed in the oral scanner, so as to obtain high-quality oral images. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present application and do not limit the present application.

[0041] Figure 1 It is a schematic structural diagram of the oral scanner provided by the embodiment of the present application when equipped with a medium-sized extension part.

[0042] Figure 2 It is a working principle diagram of the oral scanner provided by the embodiment of the present application.

[0043] Figure 3 It is a schematic structural diagram of the oral scanner provided by the embodiment of the present application when equipped with a small-sized extension part.

[0044] Figure 4 It is a schematic structural diagram of the oral scanner provided by the embodiment of the present application when equipped with a large-sized extension part.

[0045] Figure 5 It is a flowchart of the control method of the oral scanner provided by the embodiment of the present application.

[0046] Figure 6 It is a schematic diagram of the structured light provided by the embodiment of the present application.

[0047] Figure 7 It is provided based on the embodiment of the present application Figure 7 A schematic diagram of the first image of the structured light shown.

[0048] Figure 8 It is a schematic diagram of the principle for determining the second projection area provided by the embodiment of the present application.

[0049] Figure 9 It is a schematic diagram of the structured light provided by the embodiment of the present application.

[0050] Figure 10 It is provided based on the embodiment of the present application Figure 9Schematic diagram of the first image of the structured light shown

[0051] Figure 11 It is a flowchart of the control method of the oral scanner provided by an embodiment of the present application

[0052] Figure 12 It is a schematic diagram of the third image provided by an embodiment of the present application

[0053] Description of reference numerals

[0054] 100 - Oral scanner

[0055] 200, 300 - Control methods of the oral scanner

[0056] DR1 - First direction, DR2 - Second direction, DR3 - Optical axis direction of the light projector

[0057] 1 - Gripping part, 11 - Light projector, 12 - Camera

[0058] 2, 2S, 2M, 2B - Extension parts, 21 - Reflector, 22 - Opening

[0059] 3 - Structured light, 31 - Dot light, 32 - First strip light, 33 - Second strip light, 3a - Structured light unit, 3a1 - Target structured light unit, 3a2 - Structured light unit on the peripheral side in the structured light unit occupied by the mirror area

[0060] 4 - First image, 41 - Non - mirror area, 42 - Mirror area, 43 - First part pattern, 44 - Second part pattern, 4a - Dot pattern, Cb - Closed outer boundary

[0061] S1 - First projection area

[0062] S2 - Second projection area

[0063] S3 - Third projection area

[0064] S4 - Third projection area

[0065] Sp - Projection area

[0066] 5 - Third image, 51 - Black circular pattern, 52 - First non - black pattern, 53 - Second non - black pattern, 51a - Inner periphery of the black circular pattern, 51b - Outer periphery of the black circular pattern

[0067] 6 - Tongue Detailed implementation manners

[0068] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present application without creative efforts fall within the scope of protection of the present application. It can be understood that, without conflict, some technical means described in the various embodiments herein may be replaced or combined with each other.

[0069] In the description of the specification and claims of the present application, if there are terms such as "first" and "second", they are only used to distinguish the described objects and do not have any sequential or technical meanings. Thus, the objects defined with "first", "second", etc. may explicitly or implicitly include one or more of such objects. Also, similar terms such as "one" or "a" do not indicate a quantity limitation but rather indicate the existence of at least one, and "multiple" means not less than two.

[0070] Figure 1 Fig. 1 shows an oral scanner 100 provided according to an embodiment of the present application, and Figure 2 Fig. 2 shows the working principle of the oral scanner 100. The oral scanner 100 can be used to scan the oral cavity (e.g., the tongue surface and / or the inner wall of the cheek) of a subject such as a patient with oral diseases to obtain an image (e.g., a three-dimensional model image) of the oral cavity, thereby facilitating medical staff to diagnose the oral diseases of the subject. In some embodiments, the oral scanner 100 can further obtain a model of the oral cavity based on the image.

[0071] The oral scanner 100 includes a grasping portion 1 and an extension portion 2 detachably mounted on the grasping portion 1.

[0072] The grasping portion 1 includes a grasping portion housing (with some parts omitted for simplicity) and a light projector 11 and a camera 12 installed within the grasping portion housing. The grasping portion housing defines the outer shape of the grasping portion 1 and is formed into a straight handle shape that is convenient for the operator to grasp. When observing along the extending direction of the straight handle-shaped grasping portion housing, the positions of the camera 12 and the light projector 11 are at least partially staggered so that the camera 12 does not block the optical axis of the light projector 11, and at the same time, the light projector 11 does not block the optical axis of the camera 12. Therefore, the grasping portion 1 is formed to be relatively thick so that the grasping portion housing has a sufficiently large radial space to accommodate the camera 12 and the light projector 11.

[0073] In some embodiments, multiple cameras 12 are configured so as to be able to easily generate three-dimensional model images of the oral cavity (e.g., the upper jaw or the lower jaw). In this case, not only is it required that each camera 12 does not block the optical axis of the light projector 11, but also that these cameras 12 do not block each other. Therefore, the gripping portion 1 may have a larger radial dimension.

[0074] The extension portion 2 is detachably mounted to the front end of the gripping portion 1 via a locking assembly (not shown), and is formed as a columnar shape extending in the same direction as the gripping portion 1, and the extension portion 2 tapers in a direction away from the gripping portion 1. Specifically, the extension portion 2 includes an extension housing (not shown) and a mirror 21 mounted inside the extension housing. The extension housing defines the outer shape of the extension portion 2. The mirror 21 is specifically disposed at the front end of the extension housing, and at the mirror 21, the extension housing has an opening 22 for light to enter and exit. The mirror surface of the mirror 21 is inclined with respect to the optical axis of the light projector 11. In practice, the light projector 11 in the gripping portion 1 is used to project light toward the mirror 21 side, and the camera 12 in the gripping portion 1 is used to acquire an image from the mirror 21 side.

[0075] In this embodiment, by forming the extension portion 2 to taper in a direction away from the gripping portion 1, a light transmission space that gradually narrows in a direction away from the gripping portion 1 can be obtained inside the extension housing (see Figure 2 for understanding). Since such a light transmission space exactly matches the extending direction of the optical axes of the light projector 11 and the camera 12, therefore, it does not block the light projection of the light projector 11 onto the mirror 21, nor does it block the camera 12 from receiving the light from the mirror 21. Advantageously, such a design can reduce the radial dimension of the extension portion 2 so that the extension portion 2 can smoothly enter the inner wall of the patient's oral cavity and adjust its position inside the oral cavity during use.

[0076] Please also refer to Figure 1 and Figure 2 , during operation, the operator can hold the gripping portion 1 of the oral scanner 100 and insert the extension portion including the mirror 21 into the oral cavity of the patient, i.e., the subject being examined. The light projector 11 projects light toward the mirror 21 side. The light is reflected by the mirror 21 and then exits from the opening 22 of the extension portion toward the inner wall of the oral cavity (in Figure 2 , the inner wall is schematically shown as the tongue surface of the tongue 6). Then, the light is reflected by the inner wall of the oral cavity (diffuse reflection) and returns to the mirror 21 via the opening 22, and then at least part of it enters the camera 12 after being reflected by the mirror 21, so that the camera 12 obtains an image representing the shape of the oral cavity.

[0077] It can be understood that the thicker the radial dimension of the extension part 2, the larger the size of the mirror 21 that can be configured, and it is more conducive to the imager 12 to obtain high-quality oral images. However, a thick extension part 2 is not suitable for patients with small oral cavities, such as children or women. Therefore, please review Figure 1 , multiple extension parts 2S, 2M, 2B of different size models can be configured so that for different patients, an appropriate and as large as possible sized extension part 2S, 2M, 2B can be selected and assembled to the grasping part 1, thereby taking into account the convenience of operation, the experience of the examinee, and the imaging quality. For example, for a certain adult woman, such as Figure 1 , a medium-sized extension part 2M equipped with a medium-sized mirror 21 can be selected and assembled to the grasping part 1; for a certain child, a small-sized extension part 2S equipped with a small-sized mirror 21 can be selected and assembled to the grasping part 1, such as Figure 3 ; for a certain adult man, a large-sized extension part 2B equipped with a large-sized mirror 21 can be selected and assembled to the grasping part 1, such as Figure 4 . It can be understood that although the respective extension parts 2S, 2M, 2B have different sizes, the same locking structure is configured at their tails, so that they can be replaceably engaged with the same handheld part.

[0078] In the description of the present application, when it is not necessary to specifically distinguish the size models of the extension part 2, it is given the reference numeral 2, but when intentionally distinguishing the size models of the extension part 2, the corresponding reference numerals 2S, 2M, or 2B are given to it.

[0079] Since the sizes of the mirrors 21 of the extension parts 2S, 2M, 2B of different sizes are different, if the light projector 11 in the grasping part 1 projects light onto the mirrors 21 of different sizes in the different extension parts 2S, 2M, 2B with the same projection area, the following problems will occur: if the projection area size is relatively small, then the areas of the different-sized mirrors 21 irradiated by the light projector 11 are the same. Therefore, even if it is replaced with a large-sized extension part 2B, it will not bring an improvement in imaging quality, thus losing the meaning of configuring the extension parts 2S, 2M, 2B of multiple size models; if the projection area is relatively large, then part of the light will irradiate the peripheral area of the mirror 21 inside the extension part, that is, part of the light will irradiate the inner wall of the extension part housing, and part of the light irradiated on this inner wall will be reflected into the imager 12. These lights irradiated on the inner wall of the extension part housing and reflected into the imager 12 will affect the imaging quality of the oral cavity by the imager 12, because such lights do not act on the inner wall of the oral cavity as the target scanning object and cause interference to the imaging clarity of the target scanning object. Therefore, it is necessary to remove them.

[0080] Based on this, please refer to Figure 5 and combine with Figures 6 to 9, an embodiment of the present application provides a control method 200 for the foregoing oral scanner 100. This method 200 can automatically adjust the projection area size of the light projector 11 according to the size of the mirror 21 currently installed in the oral scanner 100, so as to obtain high-quality oral images. This method 200 includes the following S501 to S503:

[0081] S501, cause the light projector 11 to project structured light 3 with a first projection area S1, and use the imager 12 to obtain a first image 4, wherein the entire mirror 21 falls within the first projection area S1.

[0082] In implementation, the projection area of the structured light 3 projected by the light projector 11 can be a relatively large default value of the system, and this default projection area is set such that when Figure 1 each of the three sizes of extensions 2S, 2M, 2B is installed in the oral scanner 100, this projection area (corresponding to the circumferential boundary of the structured light 3) can completely surround the mirror 21, so that a part of the structured light 3 irradiates the inner walls of the extensions 2S, 2M, 2B located on the outer peripheral side of the mirror 21.

[0083] It should be understood that the structured light 3 projected by the light projector 11 and the planar light described later are usually divergent (for example, pyramid-shaped). Therefore, in this case, the so-called projection area is not equal everywhere. Thus, it can be understood that when comparing the sizes of the projection areas of different projection lights hereinafter, it is a comparison based on the same optical path position (for example, a position at the same distance from the light emitter).

[0084] When observing along the optical axis direction DR3 of the light projector 11, the respective structured light units 3a in the structured light 3 are arranged in a two-dimensional matrix, and the row pitch and column pitch of the two-dimensional matrix are equal. Through such a design, it is helpful to easily determine the position and size of relevant objects (for example, a distorted body located on the inner wall of the oral cavity or a tooth defect) based on the structured light 3.

[0085] In Figure 6 the illustrated embodiment, the structured light 3 projected by the light projector 11 includes a plurality of dot lights 31. When observing along the optical axis direction DR3 of the light projector 11, the plurality of dot lights 31 are arranged spaced apart from each other in a two-dimensional matrix in a first direction DR1 and a second direction DR2 perpendicular to the optical axis direction DR3, and the row pitch and column pitch of the two-dimensional matrix are equal. In Figure 6 it, each dot light 31 can be regarded as a structured light unit 3a.

[0086] In Figure 8In the illustrated embodiment, the structured light 3 projected by the light projector 11 includes a plurality of first strip lights 32 and a plurality of second strip lights 33. When observed along the optical axis direction DR3 of the light projector 11, the plurality of first strip lights 32 are arranged at equal intervals in the first direction DR1 and extend in the second direction DR2 perpendicular to the first direction DR1. The plurality of second strip lights are arranged at equal intervals in the second direction DR2 and extend in the first direction DR1, and each second strip light 33 intersects the plurality of first strip lights 32. In addition, the distance between adjacent first strip lights 32 and the distance between adjacent second strip lights 33 may be the same. In Figure 8 any two intersection points of the strip lights can be regarded as a structured light unit 3a.

[0087] S502. Based on the first image 4, determine the position and size information of the mirror 21.

[0088] It can be understood that for the part of the structured light 3 that is projected outside the mirror 21 and contacts the inner wall of the extension part 2, diffuse reflection will occur, so that at least part of it will return to the camera 12, and a first partial pattern 43 with a high degree of correspondence to the shape of this part of the structured light 3 will be generated in the first image 4. In contrast, for the other part of the structured light 3 that is projected onto the mirror 21, specular reflection will occur and it will be emitted from the opening 22 to the outside (for example, the inner wall of the oral cavity). Although a part of the light (and ambient light) emitted to the outside may be reflected again and return to the mirror 21 from the opening 22, and thus return to the camera 12, the shape of the corresponding second partial pattern 44 in the first image 4 will have a relatively poor correspondence to the shape of the original structured light 3. Therefore, by analyzing the shape difference between the relevant pattern in the first image 4 and the structured light 3, the position and size information of the mirror 21 can be known.

[0089] Based on this, please review Figure 5 , step S502 may specifically include S502a to S502b:

[0090] S502a. From the first image 4, determine the non-specular area 41 corresponding to the shape of the structured light 3 and the specular area 42 not corresponding to the shape of the structured light 3, where the non-specular area 41 surrounds the specular area 42 in the entire circumference;

[0091] S502b. According to the number and position of the structural units corresponding to the non-specular area 41, determine the position and size information of the mirror 21.

[0092] Among them, S502b may specifically include:

[0093] According to the position of the structural units corresponding to the non-specular area 41, determine the position (position information) of the mirror 21;

[0094] Determine the number of structured light units 3a occupied by the mirror area 42 as the difference between the total number of structured light units 3a in the structured light 3 and the number of structural units corresponding to the non-mirror area 41;

[0095] Based on the number of structured light units 3a occupied by the mirror area 42, determine the projected area Sp (dimension information) of the mirror 21 along the optical axis direction DR3 of the light projector 11. Thus, the position and dimension information of the mirror 21 are obtained.

[0096] For example, in Figure 6 and Figure 7 In the corresponding embodiment, the light projector 11 projects a structured light 3 including 18×18 matrix dot lights 31 in total. In the first image 4, the upper 6×18, lower 4×18, left-middle 8×4, and right-middle 8×3 dot patterns 4a correspond to the shape of the structured light 3 and are non-mirror areas 41. Therefore, the area corresponding to the middle 8×11 dot lights 31 or the structured light units 3a in the structured light 3 can be determined as the projected area Sp of the mirror area 42 along the optical axis direction DR3 of the light projector 11, and the position of the mirror 21 can be determined as the position corresponding to these 8×11 dot lights 31. It should be understood that since the size and position of the structured light 3 provided by the light projector 11 are known, the aforementioned projected area Sp and position of the mirror 21 determined can be the relative area with respect to the structured light 3 (for example, the ratio to the projection area) and the relative position with respect to the circumferential boundary of the structured light 3, rather than necessarily absolute natural values.

[0097] S503. Based on the position and dimension information, make the light projector 11 project a planar light with a second projection area S2, and use the camera 12 to obtain a second image, where the second projection area S2 is entirely within the mirror 21. Therefore, the second projection area S2 is also entirely within the aforementioned first projection area S1.

[0098] After determining the size and position of the mirror 21 relative to the projected structured light 3, the light projector 11 can project a planar light with corresponding position and size based on this information to scan the oral cavity using this planar light.

[0099] If in this step S503, the second projection area S2 of the planar light projected by the light projector 11 is set to be exactly equal to the aforementioned projected area Sp of the mirror 21 along the optical axis direction DR3 of the light projector 11, then there may be such a defect: Refer to Figures 6 to 8, since there are gaps between the structured light units 3a in the structured light 3 and there are processing errors, the aforementioned projected area Sp determined based on the number of structured light units 3a corresponding to the non-specular area 41 in the first image 4 may be slightly larger than the actual projected area of the mirror 21. This will cause a part of the planar light to irradiate outside the mirror 21, so there will still be (but a small amount of) diffuse reflection interference from the inner wall of the extension 2. Therefore, before the light projector 11 projects the planar light with the second projected area S2, the second projected area S2 can be determined first, and the second projected area S2 is smaller than the aforementioned projected area Sp and completely falls within the projected area Sp. More specifically, as Figure 8 shown, the method for determining the second projected area S2 can be: according to the closed outer boundary Cb defined by a plurality of target structured light units 3a1, the second projected area S2 is determined, where the boundary of the second projected area S2 coincides with the aforementioned closed outer boundary Cb. The plurality of target structured light units 3a1 are the structured light units 3a remaining after removing the peripheral structured light units 3a from the structured light units 3a occupied by the determined specular area 42. In this way, it can better ensure that the planar light provided by the light projector 11 completely falls within the mirror 21, and at the same time, the second projected area S2 of the planar light is as large as possible, which helps to improve the imaging quality of the oral cavity.

[0100] Next, please refer to Figure 11 and Figure 12 , the embodiment of the present application also provides another control method 300 for the aforementioned oral cavity scanner 100. This method 300 can also automatically adjust the projection area size of the light projector 11 according to the size of the mirror 21 currently installed in the oral cavity scanner 100 in order to obtain high-quality oral cavity images. In this method 300, for Figure 1 the three size models of extensions 2S, 2M, 2B that can be assembled to the same gripping part 1, the mirrors 21 configured therein all have such a design: each mirror 21 has a black body disposed on the entire periphery of the mirror 21. For example, the black body can be a resin material covering and combined with the periphery of the mirror 21. This method 300 includes the following S1101 to S1103:

[0101] S1101, make the light projector 11 project the second planar light with the third projected area S3, and use the camera 12 to obtain the third image 5, where the mirror 21 completely falls within the third projected area S3.

[0102] In practice, the initial projected area S3 of the second planar light projected by the light projector 11 can be a relatively large default value set by the system. The default third projected area S3 is set to: when Figure 1Each of the three sizes of the extension parts 2S, 2M, and 2B is installed on the oral cavity scanner 100, and the second projection area S2 (corresponding to the circumferential boundary of the second planar light) can completely surround the mirror 21, so that a part of the second planar light irradiates the inner wall of the extension parts 2S, 2M, and 2B located on the outer peripheral side of the mirror 21.

[0103] S1102, based on the closed black circular pattern 51 in the third image 5, determine the second position and size information of the mirror 21, where the black circular pattern 51 corresponds to the black body and does not limit the boundary of the third image 5.

[0104] It can be understood that for the part of the second planar light that is projected outside the mirror 21 and contacts the inner wall of the extension part 2, diffuse reflection will occur and at least part of it will return to the camera 12, and a first non-black pattern 52 corresponding to this part of the diffuse reflected light will be generated in the third image 5; moreover, for the other part of the second planar light that is projected inside the mirror 21, that is, the mirror area 42, specular reflection will occur and it will be emitted from the opening 22 to the outside (for example, the inner wall of the oral cavity), and a part of the light (and possible ambient light) that is emitted to the outside will return to the mirror 21 from the opening 22 based on the reflection of the inner wall of the oral cavity, and will return to the camera 12 based on the specular emission of the mirror 21, so that a second non-black pattern 53 corresponding to this part of the specular reflected light will be generated in the third image 5; in contrast, another part of the second planar light that is projected onto the black body on the periphery of the mirror 21 will be absorbed by the black body and will not be reflected back to the camera 12, so a black circular pattern 51 corresponding to the black body will be generated in the third image 5, and the black circular pattern 51 is just located between the aforementioned first non-black pattern 52 and the second non-black pattern 53, that is, the black circular pattern 51 does not limit the boundary of the third image 5. Therefore, based on the aforementioned characteristics in the third image 5, the black circular pattern 51 in the third image 5 can be quickly determined by using computer software-based image analysis technology, and the position and size information of the mirror 21, that is, the second position and size information, can be determined based on the position and size of the black circular pattern 51.

[0105] S1103, based on the second position and size information, make the light projector 11 project the third planar light with a fourth projection area, and use the camera 12 to obtain a fourth image, where the third planar light all falls within the mirror 21. Therefore, the third planar light also all falls within the aforementioned third planar light.

[0106] After determining the second position and size information of the mirror 21, the light projector 11 can project the fourth planar light corresponding to the position and size based on this information to scan the oral cavity with the fourth planar light.

[0107] If in step S1103, the fourth projection area of the third planar light projected by the light projector 11 is set to correspond to the outer peripheral edge 51b of the black annular pattern in the third image 5, there may be such a defect: since there are certain errors both in the third image 5 itself and in determining the specific position of the black annular pattern 51 from the third image 5 using a software program, it may lead to a deviation between the determined outer peripheral edge 51b of the black annular pattern and the actual outer peripheral edge of the black body. In this way, a part of such third planar light irradiates outside the reflector 21 and the black body, and thus there is less diffuse reflection interference from the inner wall of the extension part 2.

[0108] In view of this, in step S1103 of some embodiments, the boundary of the third planar light can be set to correspond to the inner peripheral edge 51a of the black annular pattern in the third image 5. In this way, it can not only better ensure that all of the third planar light provided by the light projector 11 falls within the outer peripheral edge of the black body (which is also the outer peripheral edge of the reflector 21), but also ensure that the boundary size (projection area) of the third planar light is as large as possible. Although a small part of the third planar light will be projected onto the black body that is not a mirror structure, since the black body will not generate diffuse reflection light reflected to the camera 12, therefore, it will not interfere with the imaging quality of the oral cavity.

[0109] In the foregoing method 200 and method 300, when using the camera 12 to acquire an image from the side of the reflector 21, the optical axis direction (corresponding to the shooting direction) and the focal length (corresponding to the shooting range) of the camera 12 can be fixed and unchanged.

[0110] In addition, method 200 and method 300 are not mutually exclusive. In some embodiments, the control method 300 for the same oral cavity scanner can include both method 200 and method 300. For example, based on the control of the operation keys provided on the gripping part 1 of the oral cavity scanner 100, it can be selectively operated in the first control mode and the second control mode. In the first control mode, the oral cavity scanner 100 is controlled by method 200, and in the second control mode, the oral cavity scanner 100 is controlled by method 300.

[0111] According to the above introduction, in the embodiments of the present application, an oral cavity scanner 100 is provided, which includes: an extension part 2 for entering the oral cavity of the subject and including a reflector 21; a gripping part 1 for the operator to grip and detachably mounted with the extension part 2, and including a light projector 11 for projecting light toward the side of the reflector 21 and a camera 12 for acquiring an image from the side of the reflector 21; a control device electrically connected to the light projector 11 and the camera 12 and configured to execute the above method 200 and / or method 300.

[0112] An embodiment of the present application further provides a computer storage medium, including: a memory, a processor connected to the memory, and program instructions stored in the memory and executable by the processor. Wherein, when the processor executes the program instructions, the above-mentioned method 200 and / or method 300 are implemented.

Claims

1. A control method for an oral scanner, the oral scanner comprising a gripping portion for an operator to grip, an extension portion detachably mounted on the gripping portion and used to enter the oral cavity of a subject, the extension portion comprising a reflector, the gripping portion comprising a light projector for projecting light to the reflector side and a camera for acquiring an image of the reflector side, characterized in that: The method comprises: The light projector projects structured light in a first projection area, and the camera is used to acquire a first image, wherein all of the reflectors fall within the first projection area; Based on the first image, determining the position and size information of the reflector; Based on the position and size information, the light projector is enabled to project planar light in a second projection area, and the camera is used to acquire a second image, wherein the second projection area entirely falls within the reflector.

2. The method according to claim 1, characterized in that: The structured light comprises: a plurality of first strips of light, when viewed along the optical axis of the light projector, the plurality of first strips of light are arranged at equal intervals in a first direction and extend in a second direction, wherein the first direction is perpendicular to the second direction; A plurality of second strip lights are arranged at equal intervals in the second direction and extend in the first direction when viewed along the optical axis direction of the light projector, and each of the second strip lights intersects with the plurality of first strip lights.

3. The method according to claim 1, characterized in that The structured light includes a plurality of point lights, and when viewed along the optical axis direction of the light projector, the plurality of point lights are arranged in a two-dimensional matrix and spaced apart from each other.

4. The method according to claim 1, characterized in that The determining, based on the first image, the position and size information of the reflector comprises: Determine, from the first image, a non-specular area corresponding to the shape of the structured light and a specular area not corresponding to the shape of the structured light, wherein the non-specular area surrounds the specular area on the entire circumference; The position and size information of the reflector are determined according to the number and position of the structured light units corresponding to the non-mirror area.

5. The method according to claim 4, characterized in that Before causing the light projector to project planar light in a second projection area, the method includes determining the second projection area to be an area smaller than the determined size information of the reflector.

6. The method according to claim 5, characterized in that Determining the position and size information of the reflector according to the number and position of the structural units corresponding to the non-mirror area includes: Determining the position of the reflector according to the position of the structural unit corresponding to the non-mirror area; Determine the difference between the total number of structured light units in the structured light and the number of structured light units corresponding to the non-mirror area as the number of structured light units occupied by the mirror area; The projection area of ​​the reflector along the optical axis of the light projector is determined according to the number of structured light units occupied by the mirror area. Determining the second projection area as an area smaller than the determined size information of the reflector includes: determining the second projection area as an area smaller than the projection area and entirely falling within the projection area.

7. The method according to claim 6, characterized in that Before causing the light projector to project planar light in a second projection area, the method includes: The second projection area is determined based on the closed outer boundary defined by multiple target structured light units, wherein the boundary of the second projection area coincides with the closed outer boundary, and the multiple target structured light units are the structured light units remaining after removing the structured light units on the peripheral side from the structured light units occupied by the determined mirror area.

8. The method according to claim 1, characterized in that: The reflector has a black body disposed on the entire periphery of the reflector, and the method further comprises: The light projector projects the second planar light in a third projection area, and the camera is used to acquire a third image, wherein all the reflectors fall within the third projection area; Determining second position and size information of the reflector based on a closed black annular pattern in the third image, wherein the black annular pattern corresponds to the black body and does not limit a boundary of the third image; Based on the second position and size information, the light projector is enabled to project third planar light with a fourth projection area, and a fourth image is acquired by using the camera, wherein all of the third planar light falls into the reflector.

9. An oral scanner, characterized in that: include: an extension portion, adapted to enter the oral cavity of a subject and comprising a reflector; a gripping portion, for an operator to grip and detachably mounted to the extension portion, comprising a light projector for projecting light to the reflector side and a camera for acquiring an image of the reflector side; A control device is electrically connected to the light projector and the camera, and is configured to execute the method according to any one of claims 1 to 8.

10. A computer storage medium, characterized in that: include: Memory, a processor connected to the memory, and program instructions stored in the memory and executable by the processor; Wherein, when the processor executes the program instructions, it implements the method as claimed in any one of claims 1 to 8.

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