Three-dimensional oral scanner

Abstract

The present invention relates to a three-dimensional oral scanner comprising: a first projector module and a second projector module which are arranged to be spaced apart from each other in a second direction perpendicular to a first direction so that illumination optical axes thereof are formed in the first direction; a camera module disposed between the first projector module and the second projector module in the second direction so that an image-capturing optical axis thereof is formed in the first direction; and mirror assemblies for respectively reflecting light emitted from the first projector module and the second projector module so that the light has a predetermined projection angle with respect to the direction of the image-capturing optical axis of the camera module. Accordingly, the range of a photographing area can be expanded, and the size of a product can be minimized.

Description

3D oral scanner

[0001] The present invention relates to a three-dimensional oral scanner, and more particularly, to a three-dimensional oral scanner for obtaining a three-dimensional image of a patient's teeth in a dental clinic or the like.

[0002] Normally, human teeth help us chew food, facilitate digestion, and play a crucial role in pronunciation. When these teeth become abnormal, their condition is diagnosed and treated, and if necessary, artificial teeth are implanted to replace them.

[0003] When teeth are lost, artificial teeth are replaced through dental implants. When using an abutment for implant prosthesis, the final prosthesis, the rounded crown, is placed on a custom abutment, requiring precise three-dimensional measurement of the abutment's shape.

[0004] Recently, there have been active attempts to directly measure the abutment in the patient's mouth using an oral scanner, that is, to use 3D scanning to design prosthetics.

[0005] A 3D oral scanner of this type can obtain 3D surface shape information of a tooth, which is a measurement target, by obtaining multiple 2D images using light reflected from the target object and imaging-processing the multiple 2D images.

[0006] For example, the "3D scanner device" disclosed in Korean Patent Registration No. 10-2444195 installs one light source and two cameras, and obtains a 3D image by acquiring multiple phase shift images from each camera.

[0007] However, in the case of conventional 3D oral scanners that use two cameras and one light source, the two cameras are positioned to capture the measurement target at different angles, which has the disadvantage of increasing the size of the product.

[0008] In addition, since each camera captures light irradiated from a single light source, there is a problem in that the camera's shooting area is limited to the range of the irradiation area where the light source is irradiated.

[0009] Accordingly, the present invention has been devised to solve the above problems, and its purpose is to provide a three-dimensional oral scanner capable of expanding the range of the photographing area.

[0010] In addition, another object of the present invention is to provide a three-dimensional oral scanner capable of minimizing the size of the product.

[0011] The above object is achieved by a 3D oral scanner according to the present invention, characterized in that it includes a first projector module and a second projector module spaced apart in a second direction perpendicular to a first direction so that an illumination optical axis is formed in a first direction, a camera module arranged so that an imaging optical axis is formed in the first direction between the first projector module and the second projector module in the second direction, and a mirror assembly for reflecting light emitted from each of the first projector module and the second projector module so that the light has a predetermined projection angle with respect to the imaging optical axis direction of the camera module.

[0012] Here, the first projector module illuminates the first grid pattern light; the second projector module illuminates the second grid pattern light; and the camera module can capture the first gap pattern light and the second grid pattern light reflected from a measurement target disposed on the capturing optical axis, respectively.

[0013] And, the mirror assembly may include a first reflection mirror arranged on the optical axis of the first projector module to reflect the first grid pattern light to a focal position on the imaging optical axis at the projection angle with respect to the imaging optical axis, and a second reflection mirror arranged on the optical axis of the second projector module to reflect the second grid pattern light to the focal position at the projection angle with respect to the imaging optical axis.

[0014] Additionally, the first reflection mirror and the second reflection mirror can adjust the reflection angles of the first grid pattern light and the second grid pattern light corresponding to the projection angle.

[0015] And, the mirror assembly may include a first mirror module that reflects the first grid pattern light to a focal position on the imaging optical axis; and a second mirror module that reflects the second grid pattern light to the focal position.

[0016] And, the first mirror module may include a first cross mirror arranged on the front side of the first projector module in the first direction to reflect the first grid pattern light from the first projector module to the front side of the second projector module, and a first focus mirror arranged on the front side of the second projector module to reflect the first gap pattern light reflected from the first cross mirror to the focus position; and the second mirror module may include a second cross mirror arranged on the front side of the second projector module in the first direction to reflect the second grid pattern light from the second projector module to the front side of the second projector module, and a second focus mirror arranged on the front side of the first projector module to reflect the second gap pattern light reflected from the second cross mirror to the focus position.

[0017] And, the first cross mirror and the second focus mirror are sequentially arranged on the front side of the first projector module; and the second cross mirror and the first focus mirror can be sequentially arranged on the front side of the second projector module.

[0018] And, the first projector module and the second projector module may be controlled to irradiate the first grid pattern light and the second grid pattern light multiple times each having a phase difference, and the imaging control unit may be configured to control each of the first grid pattern light and each of the second grid pattern light reflected from the measurement object to be photographed by the camera module, thereby generating a three-dimensional image of the measurement object in a PMP manner.

[0019] According to the above configuration, a three-dimensional oral scanner capable of expanding the range of a photographing area is provided according to the present invention.

[0020] In addition, according to the present invention, a three-dimensional oral scanner capable of minimizing the size of a product is provided.

[0021] FIG. 1 is a drawing showing the configuration of a 3D oral scanner according to the first embodiment of the present invention.

[0022] FIG. 2 is a drawing for explaining the effect of a 3D oral scanner according to an embodiment of the present invention.

[0023] FIG. 3 is a drawing showing the configuration of a 3D oral scanner according to the second embodiment of the present invention.

[0024] FIG. 4 is a drawing showing an actual tooth image captured by a three-dimensional oral scanner according to an embodiment of the present invention and an actual tooth image captured by a conventional stereo camera-type oral scanner.

[0025] The present invention relates to a three-dimensional oral scanner, characterized in that it comprises a first projector module and a second projector module spaced apart from a first direction and a second direction perpendicular to a first direction so that an illumination optical axis is formed in the first direction, a camera module arranged so that an imaging optical axis is formed in the first direction between the first projector module and the second projector module in the second direction, and a mirror assembly that reflects light emitted from the first projector module and the second projector module so that the light has a predetermined projection angle with respect to the imaging optical axis direction of the camera module.

[0026] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the present invention, and the present invention is defined solely by the scope of the claims.

[0027] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the mentioned components. Like reference numerals refer to like components throughout the specification, and "and / or" includes each and any combination of one or more of the mentioned components. Although "first", "second", etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, it should be understood that a first component mentioned below may also be a second component within the technical spirit of the present invention.

[0028] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0029] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0030] FIG. 1 is a drawing showing the configuration of a three-dimensional oral scanner (100) according to the first embodiment of the present invention.

[0031] Referring to FIG. 1, a three-dimensional oral scanner (100) according to an embodiment of the present invention may be configured to include a first projector module (111), a second projector module (112), a camera module (120), and a mirror assembly (130).

[0032] The first projector module (111) according to an embodiment of the present invention irradiates light in a first direction so that an illumination optical axis (hereinafter, referred to as a 'first illumination optical axis (151)') is formed in the first direction. In addition, the second projector module (112) is arranged to be spaced apart in a second direction perpendicular to the first direction, and irradiates light in the first direction so that an illumination optical axis (hereinafter, referred to as a 'second illumination optical axis (152)') is formed in the first direction.

[0033] That is, the first projector module (111) and the second projector module (112) are spaced apart in the first direction so that a first illumination optical axis (151) and a second illumination optical axis (152) are formed in the first direction, respectively, and irradiate light toward the first direction.

[0034] A camera module (120) according to an embodiment of the present invention is positioned between the first projector module (111) and the second projector module (112) in the second direction. In addition, the camera module (120) also photographs a measurement target positioned in front in the first direction with an imaging optical axis (153) formed in the first direction.

[0035] The mirror assembly (130) according to an embodiment of the present invention reflects the light emitted from the first projector module (111) and the second projector module (112) so that the light has a predetermined projection angle and a direction of the imaging optical axis (153) of the camera module (120). In one embodiment, the mirror assembly (130) can reflect the light emitted from the first projector module (111) and the second projector module (112) so that the light has a projection angle and the imaging optical axis (153) to a focus position on the imaging optical axis.

[0036] According to the above configuration, when the first projector module (111) and the second projector module (112) are arranged to irradiate light in the first direction, the mirror assembly (130) reflects the light irradiated from the first projector module (111) and the second projector module (112) so that the light has a projection angle in the direction of the measurement target, that is, in the direction of the imaging optical axis (153) of the camera module (120), thereby providing an effect of reducing the size of the product due to the existing oral projector arranging a pair of camera modules (120) at an angle.

[0037] In addition, by using the light irradiated from the first projector module (111) and the second projector module (112), one camera module (120) photographs the measurement target, thereby enabling photography in a wider shooting area than when photographing the measurement target using a conventional pair of camera modules (120) and one projector module.

[0038] Referring to Fig. 2, the left side of Fig. 2 is a drawing showing a 3D oral scanner (100) according to an embodiment of the present invention, and the right side is a drawing showing a conventional oral scanner with a dual camera structure. The conventional oral scanner with a dual camera structure has a pair of camera modules (1211, 1212) arranged on both sides with a projector module (1111) at the center.

[0039] Conventional oral scanners with a dual camera structure use only the overlapping area of ​​the two camera modules (1211, 1212), so when measuring a 3D image, the blind spot is formed by combining the blind spots of the left and right camera modules (1211, 1212). Therefore, the problem arises that the measurable area is reduced compared to the entire FOV of the camera modules (1211, 1212).

[0040] On the other hand, the 3D oral scanner (100) according to the embodiment of the present invention can measure even if only one side of the light irradiated to the first projector module (111) and the second projector module (112) is effective, so that the blind spot is minimized. Since the blind spot of one of the first projector module (111) and the second projector module (112) is covered by the other, the measurable area becomes the entire FOV area of ​​the camera module (120), so that the measurable area has the effect of being wider than that of a conventional oral scanner with a dual camera structure.

[0041] Accordingly, when scanning teeth with a 3D oral scanner (100) according to an embodiment of the present invention, the visual zone according to the curved surface of the teeth is minimized, thereby increasing the effective area created with a single scan, thereby providing the effect of shortening the overall scanning time.

[0042] Meanwhile, the first projector module (111) according to the first embodiment of the present invention can illuminate the first grid pattern light (161). And, the second projector module (112) can illuminate the second grid pattern light (162).

[0043] In one embodiment, the first projector module (111) can irradiate a first grid pattern light (161) having a grid pattern with a predetermined wavelength to a measurement target. For example, a plurality of first grid pattern lights (161) having a phase shift of π / 2 each, for example, four first grid pattern lights having a phase difference, can be sequentially irradiated to the measurement target.

[0044] Likewise, the second projector module (112) can irradiate the second grid pattern light (162) of the grid pattern having a predetermined wavelength to the measurement target. For example, a plurality of second grid pattern lights (162) with a phase shift of π / 2 each, for example, four second grid pattern lights with a phase difference, can be sequentially irradiated to the measurement target.

[0045] Here, the 3D oral scanner (100) according to the embodiment of the present invention may be configured to include an imaging control unit (140).

[0046] The imaging control unit (140) controls the first projector module (111) to irradiate a plurality of first grid pattern lights (161) toward the measurement target, and controls the camera module (120) to sequentially photograph the reflected light reflected from the measurement target by each of the first grid pattern lights (161).

[0047] Likewise, the imaging control unit (140) controls the second projector module (112) to irradiate a plurality of second grid pattern lights (162) toward the measurement target, and controls the camera module (120) to sequentially photograph the reflected light reflected from the measurement target by each of the second grid pattern lights (162).

[0048] As described above, by using images sequentially captured by the camera module (120) using the first grid pattern light (161) and the second grid pattern light (162), the imaging control unit (140) acquires a three-dimensional image of the measurement target based on the PMP (Phase measuring profilometry) method.

[0049] In one embodiment, the imaging control unit (140) controls the first projector module (111) to irradiate four first grid pattern lights (161), and can generate one three-dimensional image using four images captured by the camera module (120) for each first grid pattern light (161).

[0050] Likewise, the imaging control unit (140) controls the second projector module (112) to irradiate four second grid pattern lights (162), and can generate one three-dimensional image using four images captured by the camera module (120) for each second grid pattern light (162).

[0051] Here, a shaded area may occur depending on the height of the measurement target, and thus, an area where height information is not generated, i.e., a pixel, may occur in each of the three-dimensional image generated by the investigation of the first projector module (111) and the three-dimensional image generated by the investigation of the second projector module (112).

[0052] At this time, the imaging control unit (140) can generate a final 3D image using the height information for pixels where height information is generated on only one side. In addition, for pixels where height information exists in both 3D images, the final height information can be determined in various ways.

[0053] For example, the average of two pieces of height information can be used, the reliability can be calculated and a weighted average can be used according to the reliability, or the height information on one side with high reliability can be used.

[0054] In an embodiment of the present invention, a method of generating a 3D image using the PMP method can be applied to various known methods, and it goes without saying that the technical idea of ​​the present invention is not limited to the method of generating a 3D image.

[0055] Meanwhile, the mirror assembly (130) according to the first embodiment of the present invention may be configured to include a first reflection mirror (131) and a second reflection mirror (132), as illustrated in FIG. 1.

[0056] The first reflection mirror (131) is positioned on the irradiation optical axis of the first projector module (111). Then, the first reflection mirror (131) reflects the first grid pattern light (161) irradiated from the first projector module (111) in the first direction, i.e., toward the irradiation optical axis, to a focal position on the imaging optical axis (153) while having a projection angle with the imaging optical axis (153) of the camera module (120).

[0057] The second reflection mirror (132) is positioned on the irradiation optical axis of the second projector module (112). Then, the second reflection mirror (132) reflects the second grid pattern light (162) irradiated from the second projector module (112) in the first direction, i.e., toward the irradiation optical axis, to a focal position on the imaging optical axis (153) while having a projection angle with the imaging optical axis (153) of the camera module (120).

[0058] According to the above configuration, the first grid pattern light (161) irradiated from the first projector module (111) is reflected by the first reflection mirror (131) onto the imaging optical axis (153), and the second pattern light irradiated from the first projector module (111) is reflected by the second reflection mirror (132) onto the imaging optical axis (153), so that the first projector module (111) and the second projector module (112) can be arranged toward the first direction.

[0059] Here, the first reflection mirror (131) and the second reflection mirror (132) are arranged to adjust the reflection angles of the first grid pattern light (161) and the second grid pattern light (162) in response to the PMP (Phase Measuring Profilometry) projection angle based on optical triangulation, so that the grid pattern can be configured to illuminate a measurement target placed at a focal distance of the camera module (120) at a projection angle.

[0060] Hereinafter, the configuration of a three-dimensional oral scanner (100a) according to a second embodiment of the present invention will be described in detail with reference to FIG. 3.

[0061] The configuration of the first projector module (111), the second projector module (112), the camera module (120), and the imaging control unit (140) of the 3D oral scanner (100) according to the second embodiment of the present invention corresponds to the first embodiment described above, and thus a detailed description thereof is omitted.

[0062] A mirror assembly (130a) according to a second embodiment of the present invention may be configured to include a first mirror module (131a, 131b) and a second mirror module (132a, 132b).

[0063] The first mirror module (131a, 131b) according to an embodiment of the present invention reflects the first grid pattern light (161) to a focal position on the imaging optical axis (153) while having a projection angle with the imaging optical axis (153). In addition, the second mirror module (132a, 132b) reflects the second pattern light to a focal position on the imaging optical axis (153) while having a projection angle with the imaging optical axis (153).

[0064] In one embodiment, the first mirror module (131a, 131b) may be configured to include a first cross mirror (131a) and a first focusing mirror (131b).

[0065] Here, the first cross mirror (131a) can be arranged on the front side of the first projector module (111) in the first direction, i.e., on the first illumination optical axis (151) of the first projector module (111). Then, the first cross mirror (131a) reflects the first grid pattern light (161) irradiated from the first projector module (111) to the front side of the second projector module (112). Then, the first focus mirror (131b) is arranged on the front side of the second projector module (112) and reflects the first grid pattern light (161) reflected from the first cross mirror (131a) to the focus position.

[0066] Symmetrically, the second mirror module (132a, 132b) may be configured to include a second cross mirror (132a) and a second focusing mirror (132b).

[0067] The second cross mirror (132a) may be arranged on the front side of the second projector module (112) in the first direction, i.e., on the second illumination optical axis (152) of the second projector module (112). Then, the second cross mirror (132a) reflects the second grid pattern light (162) irradiated from the second projector module (112) to the front side of the first projector module (111). Then, the second focus mirror (132b) is arranged on the front side of the first projector module (111) and reflects the second grid pattern light (162) reflected from the second cross mirror (132a) to the focus position.

[0068] Here, as illustrated in FIG. 3, the first cross mirror (131a) and the second focus mirror (132b) are sequentially arranged on the front side in the first direction of the first projector module (111). And, the second cross mirror (132a) and the first focus mirror (131b) are sequentially arranged on the front side in the first direction of the second projector module (112).

[0069] According to the above configuration, when the projection angle is set small to increase the measurement resolution, the projection angles of the first projector module (111) and the second projector module (112) in the first embodiment illustrated in FIG. 1 become small, and when the lengths of the first reflection mirror (131) and the second reflection mirror (132) must be increased, the first cross mirror (131a) and the first focus mirror (131b), the second cross mirror (132a) and the second focus mirror (132b) are arranged to reflect the first grid pattern light (161) and the second grid pattern light (162) twice, thereby reducing the size of the mirror assembly (130).

[0070] FIG. 4 is a drawing showing an actual tooth image captured by a three-dimensional oral scanner (100, 100a) according to an embodiment of the present invention and an actual tooth image captured by a conventional stereo camera-type oral scanner.

[0071] As shown in (a) of FIG. 4, in the case of an actual tooth image captured by a 3D oral scanner (100, 100a) according to an embodiment of the present invention, it can be confirmed that the tooth side curved portion is normally scanned when scanning in the vertical direction, whereas a conventional stereo camera type oral scanner is not scanned due to the difference in the measurable area shown in FIG. 2, as shown in (b) of FIG. 4. Therefore, when using a conventional stereo camera type oral scanner, an additional scan is required by turning the tooth side.

[0072] Although certain embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that modifications may be made to the embodiments without departing from the spirit or scope of the invention. The scope of the invention is defined by the appended claims and their equivalents.

[0073] [Explanation of symbols]

[0074] 100: 3D oral scanner 111: 1st projector module

[0075] 112; Second projector module 120: Camera module

[0076] 130.130a: Mirror assembly 131: First reflecting mirror

[0077] 131a: First cross mirror 131b: First focusing mirror

[0078] 132: Second reflecting mirror 132a: Second crossing mirror

[0079] 132b; Second focusing mirror 140: Imaging control unit

[0080] 151: First lighting axis 152: Second lighting axis

[0081] 161: First grid pattern light 162; Second grid pattern light

[0082] The present invention can be applied to the field of oral scanners for creating a three-dimensional model of the oral cavity in dentistry, etc.

Claims

1. In 3D oral scanner, A first projector module and a second projector module are arranged spaced apart in a second direction perpendicular to the first direction so that a lighting optical axis is formed in the first direction; A camera module arranged so that an imaging optical axis is formed in the first direction between the first projector module and the second projector module in the second direction; A 3D oral scanner characterized by including a mirror assembly that reflects light emitted from the first projector module and the second projector module so that the light has a predetermined projection angle and a direction of the imaging optical axis of the camera module.

2. In paragraph 1, The first projector module illuminates the first grid pattern light; The second projector module illuminates the second grid pattern light; A 3D oral scanner, characterized in that the camera module captures the first gap pattern light and the second grid pattern light reflected from a measurement target placed on the imaging optical axis.

3. In paragraph 2, The above mirror assembly A first reflection mirror arranged on the optical axis of the first projector module, which reflects the first grid pattern light to a focal position on the imaging optical axis and has the projection angle with the imaging optical axis; A 3D oral scanner, characterized in that it includes a second reflection mirror arranged on the optical axis of the second projector module and reflecting the second grid pattern light toward the focal position while having the projection angle and the imaging optical axis.

4. In paragraph 3, A 3D oral scanner, characterized in that the first reflection mirror and the second reflection mirror adjust the reflection angle of the first grid pattern light and the second grid pattern light in response to the projection angle.

5. In paragraph 2, The above mirror assembly A first mirror module that reflects the first grid pattern light to a focal position on the imaging optical axis; A 3D oral scanner characterized by comprising a second mirror module that reflects the second grid pattern light to the focus position.

6. In paragraph 5, The above first mirror module A first cross mirror arranged on the front side of the first projector module in the first direction to reflect the first grid pattern light from the first projector module to the front side of the second projector module; A first focus mirror is disposed on the front side of the second projector module and reflects the first gap pattern light reflected from the first cross mirror to the focus position; The above second mirror module A second cross mirror arranged on the front side of the second projector module in the first direction to reflect the second grid pattern light from the second projector module to the front side of the second projector module; A 3D oral scanner characterized by comprising a second focus mirror disposed on the front side of the first projector module and reflecting the second gap pattern light reflected from the second cross mirror to the focus position.

7. In paragraph 6, The first cross mirror and the second focusing mirror are sequentially arranged on the front side of the first projector module; A 3D oral scanner, characterized in that the second cross mirror and the first focusing mirror are sequentially arranged on the front side of the second projector module.

8. In paragraph 2, A 3D oral scanner characterized by comprising an imaging control unit that controls the first projector module and the second projector module to irradiate a plurality of the first grid pattern lights and a plurality of the second grid pattern lights having a phase difference, and controls each of the first grid pattern lights and each of the second grid pattern lights reflected from the measurement object to be photographed by the camera module, thereby generating a 3D image of the measurement object in a PMP manner.

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