Optical system, oral cavity digital impression instrument equipped with optical system and image acquisition method

Abstract

The invention relates to an optical system which comprises a light path transmitting subsystem, a scanning reflector (6) and an image receiving and processing subsystem. The light path emission subsystem comprises an illumination module (1), a light modulation module (4) and a curved prism (21). The curved surface prism comprises a light incident surface (21A), a reflection-transmission composite interface (21B) and a curved surface (21C) plated with a reflecting film, and is used for changing the direction of a light path and focusing the light path, so that the light path enters from the light incident surface, is reflected by the reflection-transmission composite interface, is reflected by the curved surface and is focused; and then the light is emitted from the reflection-transmission composite interface and enters the light modulation module at a specific angle. The invention also relates to an oral digital impression instrument equipped with the optical system. According to the optical system, the curved prism is used for replacing a traditional lens and reflector combination, the space size of the oral cavity digital impression instrument is remarkably reduced, and the requirements for miniaturization and portability are met.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an optical system and a dental digital impression device equipped with the optical system. The present invention also optionally relates to an image acquisition method implemented by using the optical system. Background Art

[0002] A dental digital impression device is a device that uses computer technology and three-dimensional imaging technology to obtain and reconstruct dental impressions. With the development of technology and the increase in market demand, people's requirements for dental digital impression devices are gradually increasing. As a handheld medical device, traditional dental digital impression devices are large in size and complex in structure, and do not have sufficient flexibility when used. Therefore, the dental medical industry's demand for miniaturized dental digital impression devices is gradually emerging.

[0003] Applicants Suzhou Qisda Optoelectronics Co., Ltd. and Qisda Technology Co., Ltd. submitted a Chinese invention patent application with publication number CN105266815A on September 17, 2015, which discloses an electronic device. The electronic device includes a light source system, a second optical system and an imaging system, the second optical system includes a first prism and a first reflective element, the first prism includes a first surface, a second surface and a third surface adjacent to each other, the light source system is used to provide light along a first optical path, the light penetrates the first prism and the fourth surface of the first reflective element and then enters the fifth surface of the first reflective element, the light is reflected by the fifth surface and then sequentially penetrates the fourth surface and the first prism and then enters the target object along the second optical path, the light reflected by the target object penetrates the third surface and then enters the second surface, and after being reflected by the second surface, it enters the first surface along the fourth optical path, the light penetrates the first surface and propagates to the imaging system, wherein the first optical path and the fifth optical path have a fourth angle, and the fourth angle is greater than 0 degrees and less than 45 degrees.

[0004] The above optical system has a large spatial dimension, especially a large dimension in the radial direction, which makes the device equipped with the optical system relatively bulky and not conducive to handheld operation, thus adversely affecting the portability and applicability of the device.

[0005] Therefore, there is an urgent need for a more compact, efficient and easy-to-hold optical system design to meet the miniaturization and portability requirements of modern medical equipment and other precision instruments. Summary of the invention

[0006] The present invention is completed in view of the above-mentioned needs, and its purpose is to provide an oral digital impression instrument with a miniaturized optical system.

[0007] According to a first aspect of the present invention, there is provided an optical system comprising:

[0008] An optical path emission subsystem, which generates an optical path with pattern information and emits the optical path into a target object, such as an area to be collected in the oral cavity;

[0009] A scanning mirror for reflecting a light path with pattern information into a target object and deriving an image in the target object; and

[0010] An image receiving and processing subsystem receives and processes the image derived from the scanning reflector.

[0011] Among them, the optical path transmission subsystem includes:

[0012] An illumination module, the illumination module generating a light path, such as a monochromatic or polychromatic light path;

[0013] A light modulation module, the light modulation module imparts pattern information to the light path; and

[0014] A curved prism is arranged between the lighting module and the light modulation module. The curved prism includes a light incident surface, a reflection-transmission composite interface, and a curved surface coated with a reflective film. The curved prism is used to change the direction of the light path and focus the light path. The light path enters from the light incident surface, is reflected by the reflection-transmission composite interface, is reflected and focused by the curved surface, and then is emitted from the reflection-transmission composite interface and enters the light modulation module at a specific angle.

[0015] In the above technical solution, the term "pattern information" means various patterns such as stripes, codes, array graphics, etc., which can be compiled by computer programs into audio, video, image, text and other information.

[0016] The term "light modulation module" not only covers digital micromirror devices (DMDs), but also includes light modulation elements such as gratings or LCD+HTPS (high temperature polysilicon). The term "reflection-transmission composite interface" refers to an arrangement in which a reflective film is coated at the first reflection position of the reflection-transmission composite interface, wherein the light-emitting surface is a light-transmitting surface, and the remaining surfaces are coated with reflective films to form reflective surfaces. This arrangement is limited only to the case where the incident angle is less than the critical angle of total reflection. This arrangement is well known to those skilled in the art and will not be described in detail here.

[0017] By using a curved prism to replace the traditional multiple discrete optical elements, such as a lens and a reflector combination, the spatial size of the optical system can be significantly reduced, thereby obtaining a miniaturized optical system, which is more suitable for handheld instruments such as oral digital impression devices. Since the curved prism integrates the light incident surface, the reflection-transmission composite interface and the curved surface, and uses a curved surface with a partial light-transmitting surface and a partial reflective surface coated with a reflective film or having a total reflection function to change the direction of the light path, the entire light path can be completed in a more compact space. Due to the multi-faceted design of the curved prism, it can effectively fold the light path without sacrificing performance, which not only reduces the overall space occupied, but also allows other components to be arranged more closely. The illumination module, curved prism, light modulation module and projection lens in the optimized optical system are arranged in sequence along the emission direction of the light path. The light path emitted from the illumination module to the curved prism and the light path emitted from the light modulation module via the projection lens to the scanning reflector are roughly overlapped in the radial direction, thereby reducing the spatial size of the optical system in the radial direction, reducing the radial size of the shell enclosing the optical system, and helping to achieve the miniaturization of the equipment, which is convenient for the staff to operate by hand.

[0018] Although the above-mentioned optical system is recorded as an oral digital impression device in each embodiment of the specification, technicians in this field should understand that the optical system can also be used for other three-dimensional imaging equipment, such as oral implant surgery navigation and positioning equipment, CBCT, facial scanning equipment, etc. in medical devices.

[0019] Preferably, the reflection-transmission composite interface can be formed with a light-transmitting surface and a reflective surface, that is, part of the interface is a light-transmitting surface and part of the interface is a reflective surface. Under this condition, the incident angle of the light path transmitted from the light-incident surface to the reflection-transmission composite interface is greater than the critical angle of total reflection of the curved prism, and the incident angle of the light path reflected from the curved surface and focused to the reflection-transmission composite interface is less than the critical angle of total reflection of the curved prism.

[0020] In the art, the above-mentioned reflection-transmission composite interface can be realized by various means. For example, a reflection film is coated at or near the first reflection position of the reflection-transmission composite interface as a reflection surface, and the portion of the reflection-transmission composite interface not coated with the reflection film is used as a light-transmitting surface. When the incident angle of the light path transmitted from the light-incident surface to the reflection-transmission composite interface is greater than the critical angle of total reflection of the curved prism, the light path is totally reflected to the curved surface; when the incident angle of the light path reflected from the curved surface and focused to the reflection-transmission composite interface is less than the critical angle of total reflection of the curved prism, the light path is transmitted through the reflection-transmission composite interface. The curved surface of the curved prism can also be designed as a light path convergence curved surface, and the light path reflected from the reflection-transmission composite interface to the curved surface is reflected back to the reflection-transmission composite interface after being focused.

[0021] In another embodiment of the present invention, the optical path emission subsystem further includes a projection lens, which is used to project the optical path of the pattern information onto the scanning reflector. The term "projection lens" not only refers to a single projection lens, but also covers a projection lens group composed of two or more projection lenses, and these variations should all fall within the scope of protection of the present invention.

[0022] In yet another embodiment of the present invention, the image receiving and processing subsystem may include:

[0023] a camera lens that focuses and shapes the optical path including the image derived from the scanning mirror;

[0024] an image sensor module for processing an image derived from the scanning mirror; and

[0025] A multifaceted reflection prism is arranged between the camera lens and the image sensor module, and is used to receive and reflect the focused and shaped light path. The multifaceted reflection prism includes a light incident surface, a light exiting surface, a first reflection surface and a second reflection surface. The first reflection surface and the second reflection surface are coated with a reflection film. The light path enters the first reflection surface through the light incident surface, is reflected from the first reflection surface to the second reflection surface, and is then reflected from the second reflection surface to the light exiting surface before being emitted from the light exiting surface.

[0026] Similarly, the term "camera lens" not only refers to a single camera lens, but also covers a camera lens group consisting of two or more camera lenses. These variations should all fall within the protection scope of the present invention.

[0027] Preferably, the light incident surface and the first reflective surface may form a first angle, the first reflective surface and the second reflective surface may form a second angle, and the second reflective surface and the light emitting surface may form a third angle. More specifically, the first angle may be selected within the range of 15° to 75°, preferably 45°; the second angle may be selected within the range of 15° to 150°, preferably 60°; and the third angle may be selected within the range of 15° to 90°, preferably 45°.

[0028] By using a multi-faceted reflection prism instead of a traditional reflector to reflect the image multiple times, the direction of the light path can be effectively adjusted so that the image can be reflected to the desired position. Moreover, the sensor can be arranged between the projection lens and the camera lens. On the basis of the optical system of the oral impression device in the prior art, the arrangement of the optical system in the radial space is further optimized, so that the radial space distance occupied by the optical system is smaller, which helps to reduce the size of the housing enclosing the optical system in the radial direction, and is conducive to the holding operation of the device.

[0029] In a preferred embodiment, the curved prism is implemented as a composite lens composed of a triangular prism and a curved lens, and the curved lens is formed as the curved surface of the curved prism.

[0030] Preferably, the curved lens can be a spherical lens. However, the protection scope of the present invention is not limited to the spherical lens, and other curved lenses that can achieve the same function are also included.

[0031] By breaking down complex curved prisms into standard prisms and curved lenses, each component can be independently produced using mature manufacturing processes. Prisms and curved lenses are common components in the optical field, and their production processes are mature and stable, making them easy to mass produce and control quality. Replacing curved prisms with more complex manufacturing processes further reduces the difficulty of production.

[0032] In the light path emission subsystem, the lighting module, the curved prism, the light modulation module and the projection lens are arranged in sequence along the emission direction of the light path. In this case, the light incident surface faces the lighting module, the light path emitted from the lighting module enters the curved prism via the light incident surface, and the light path is emitted from the reflection-transmission composite interface to the light modulation module.

[0033] In the image receiving and processing subsystem, the camera lens, the multi-faceted reflective prism and the image sensor module are arranged in sequence along the reflection direction of the light path. In this case, the light path is emitted from the camera lens to the multi-faceted reflective prism via the light incident surface, and then to the image sensor module via the light exit surface.

[0034] The second aspect of the present invention relates to a dental digital impression device equipped with the optical system as described in the first aspect of the present invention.

[0035] When the optical system is applied to an oral digital impression device, the target object is the oral cavity. Of course, when the optical system is applied to other medical equipment, the target object may also be other organs or tissues that require imaging examination.

[0036] In addition, the third aspect of the present invention also provides an image acquisition method, comprising the following steps:

[0037] Using the optical system according to the first aspect of the present invention, the illumination module generates a light path, and the light path is incident on the light modulation module at a specific angle via the curved prism;

[0038] The optical modulation module receives the optical path and makes the optical path carry pattern information;

[0039] The projection lens receives the light path with pattern information and projects it to the scanning reflector;

[0040] The scanning mirror reflects the light path with pattern information to the target object, and exports the image inside the target object to the camera lens;

[0041] The camera lens focuses and shapes the light path including the image derived from the scanning reflector, and emits it to the image sensor module via the multi-faceted reflective prism;

[0042] The image sensor module processes the image.

[0043] Since a curved prism or a compound lens is used to replace the combination of a reflector and a lens in the prior art, it is possible to effectively fold the optical path without sacrificing performance, which not only reduces the space occupied by the whole, but also allows other components to be arranged more closely. In this way, the illumination module, the curved prism, the light modulation module and the projection lens will be roughly distributed in a straight line, reducing the radial space occupied by the optical path emission subsystem.

[0044] In addition, since a multi-faceted reflecting prism according to an embodiment of the present invention is used instead of a reflecting mirror in the prior art, the reflected light can be reflected radially along the inner side of the oral impression device, so that the image sensor module can be arranged between the camera lens and the projection lens, further reducing the radial space occupied by the optical system, which is beneficial to reducing the spatial size of the outer shell enclosing the optical system for easy handholding. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0046] Figure 1 A schematic diagram of an optical system for an oral digital impression device according to the prior art;

[0047] Figure 2 is a schematic diagram of an optical system according to an embodiment of the present invention;

[0048] Figure 3A and 3B They are a side view and a stereoscopic perspective view of a first embodiment of a curved prism in an optical system according to an embodiment of the present invention;

[0049] Figure 4A and 4B They are a side view and a stereoscopic perspective view of a second embodiment of a curved prism in an optical system according to an embodiment of the present invention;

[0050] Figure 5A is a three-dimensional perspective view of a multi-faceted reflecting prism in an optical system according to an embodiment of the present invention;

[0051] Figure 5B Shown coated on Figure 5A The reflective film on the multi-faceted reflecting prism in;

[0052] Figure 6 is a schematic diagram comparing an optical system according to an embodiment of the present invention with an optical system in the prior art;

[0053] Figure 7 is a schematic diagram comparing radial lengths of an optical system according to an embodiment of the present invention and an optical system in the prior art;

[0054] Figure 8 Schematic diagram of an image acquisition method of an optical system according to an embodiment of the present invention.

[0055] Reference numerals list

[0056] 1 lighting module;

[0057] 2 first reflector;

[0058] 3. First lens;

[0059] 4 optical modulation module;

[0060] 41 Digital Micromirror Device

[0061] 42 DMD Controller

[0062] 5. Projection lens;

[0063] 6 Scanning mirror;

[0064] 7 Camera lens;

[0065] 8 second reflector;

[0066] 9 Image sensor module;

[0067] 21 curved prism;

[0068] 21A light incident surface;

[0069] 21B reflection-transmission composite interface;

[0070] 21C curved surface;

[0071] 22 Prism;

[0072] 23 curved lens;

[0073] 81 Multi-faceted reflecting prism;

[0074] 81A light incident surface;

[0075] 81B light-emitting surface;

[0076] 81C first reflecting surface;

[0077] 81D second reflection surface;

[0078] 100 Oral.

[0079] H1, H2 radial distance DETAILED DESCRIPTION

[0080] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0081] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate to facilitate understanding of the embodiments described in the present application. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0082] In this application, the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", etc. are based on the orientations or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0083] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances.

[0084] In addition, the terms "install", "set up" and "arrange" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0085] In addition, the term "bonding" as used in this application should be understood as any method that can provide sufficient strength and durability, such as the process of permanently or semi-permanently bonding two or more elements together by using adhesives, bonding materials or other similar means. The term "radial" as used in this application refers to a direction generally perpendicular to the longer side of the device.

[0086] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. To make the scheme of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0087] Figure 1 FIG. 1 is a schematic diagram of an optical system for an oral digital impression device in the prior art. Such an optical system generally includes an optical path transmitting subsystem, a scanning reflector, and an image receiving and processing subsystem. Figure 1 As shown, the light path emission subsystem includes an illumination module 1, a first emission mirror 2, a first lens 3, an optical modulation module 4, and a projection lens 5. The image receiving and processing subsystem includes a camera lens 7, a second reflector 8, and an image sensor module 9. The illumination module 1, the first reflector 2, the first lens 3, the optical modulation module 4, the projection lens 5, and the scanning reflector 6 are sequentially arranged along the light path emission direction, which is the direction in which the light path passes through the above optical elements. Figure 1 The scanning reflector 6, the camera lens 7, the second reflector 8 and the image sensor module 9 are sequentially arranged along the light path reflection direction, which is the direction in which the light path including the image derived by the scanning reflector 6 passes through the above optical elements. Figure 1 The image sensor module 9 is arranged above the second reflector 8, and the light path emitted from the illumination module 1 to the first reflector 2 and the light path emitted from the light modulation module 4 to the scanning reflector 6 via the projection lens 5 have a large spatial distance in the radial direction. As a result, the illumination module 1, the first reflector 2, the light modulation module 4 and the projection lens 5 occupy a large space in the radial space.

[0088] Figure 2 FIG. 1 is a schematic diagram of an optical system for a digital oral impression device according to an embodiment of the present invention. The optical system also includes an optical path emission subsystem, a scanning reflector 6, and an image receiving and processing subsystem. Figure 2As shown, the optical path emission subsystem generates an optical path with pattern information and emits the optical path to the scanning reflector 6. The scanning reflector 6 is used to reflect the optical path with pattern information to the target object, that is, the oral cavity 100 or the area to be collected in the oral cavity and derive the image in the target object. The image receiving and processing subsystem receives and processes the image derived by the scanning reflector 6, that is, the image of the target object. The optical path emission subsystem includes: an illumination module 1, a curved prism 21, a light modulation module 4 and a projection lens 5. The illumination module 1 generates an optical path. The light modulation module 4 preferably adopts a DMD module, including: a digital micromirror element 41, which integrates a large number of independently controllable reflector arrays to receive the incident optical path and reflect the optical path with pattern information at a certain angle; and a DMD controller 42, which is used to control the movement of the reflector array in the digital micromirror element 41. The projection lens 5 is used to project the optical path with pattern information to the scanning reflector 6.

[0089] Figure 3A and 3B FIG. 2 shows a curved prism 21 in an optical system according to an embodiment of the present invention. Figure 3B As shown, the curved prism 21 includes a light incident surface 21A, a reflection-transmission composite interface 21B, and a curved surface 21C coated with a reflection film. The curved prism 21 is disposed between the light modulation module 4 and the illumination module 1 .

[0090] The light path emitted from the illumination module 1 enters the curved prism 21 through the light incident surface 21A of the curved prism 21, and the light path is reflected twice inside the curved prism 21, and leaves the curved prism 21 through the reflection-transmission composite interface 21B of the curved prism 21 and enters the light modulation module 4. Specifically, the curved prism 21 is used to change the direction of the light path and focus the light path. When the light path enters from the light incident surface 21A, it is reflected through the reflection-transmission composite interface 21B, and then reflected and focused through the curved surface 21C, and then emitted from the reflection-transmission composite interface 21B and enters the light modulation module 4 at a specific angle.

[0091] It should be noted that the reflection-transmission composite interface 21B is formed with a light-transmitting surface and a reflective surface. The incident angle of the light path transmitted from the light-incident surface 21A to the reflection-transmission composite interface 21B needs to be greater than the critical angle of total reflection of the curved prism 21, so that total reflection occurs on the reflection-transmission composite interface 21B. The incident angle of the light path reflected from the curved surface 21C and focused to the reflection-transmission composite interface 21B needs to be less than the critical angle of total reflection of the curved prism 21, so that the light path that reaches the reflection-transmission composite interface 21B again can be completely emitted from the reflection-transmission composite interface 21B.

[0092] The curved surface 21C of the curved prism 21 is preferably a light path converging curved surface, so that the light path reflected from the reflection-transmission composite interface 21B to the curved surface 21C is focused and then reflected back to the reflection-transmission composite interface 21B.

[0093] Return to Figure 2 As shown, in the light path emission subsystem, the lighting module 1, the curved prism 21, the light modulation module 4, the projection lens 5 and the scanning reflector 6 are sequentially arranged along the emission direction of the light path. In the image receiving and processing subsystem, the camera lens 7, the multi-faceted reflection prism 81 and the image sensor module 9 are sequentially arranged along the reflection direction of the light path. The image sensor module 9 is arranged between the camera lens 7 and the projection lens 5, and the light path emitted from the lighting module 1 to the curved prism 21 and the light path emitted from the light modulation module 4 to the scanning reflector 6 via the projection lens 5 are roughly overlapped in the radial direction. That is, the lighting module 1, the curved prism 21, the light modulation module 4 and the projection lens 5 occupy a small space in the radial space. Therefore, the present invention uses the curved prism 21 to replace the combination of the first reflector 2 and the first lens 3 in the prior art, which is further beneficial to the integration of various components of the optical system and promotes the miniaturization of the oral digital impression instrument.

[0094] Alternatively, Figure 4A and 4B As shown, the curved prism 21 can also be implemented as a composite lens composed of a prism 22 and a curved lens 23. In actual production, the curved surface of the curved prism 21 is difficult to process and has a high cost. Figure 4A and 4B The embodiment shown provides another solution that can achieve the same technical effect and replace the curved prism 21. It can be seen that the curved lens 23 of the composite lens is bonded to the lower surface of the prism 22 by gluing or other means, for example, and the light path can pass through the gluing surface of the curved lens 23 and the prism 22. Moreover, the curved lens 23 of the composite lens has the same curvature as the curved surface 21C of the curved prism 21 shown in FIG. 3, thereby achieving the same optical effect as the curved prism 21. Therefore, the curved lens 23 of the composite lens can replace the curved surface 21C of the curved prism 21.

[0095] In addition, the light incident surface 21A and the reflection-transmission composite interface 21B of the composite lens are identical to the light incident surface 21A and the reflection-transmission composite interface 21B of the curved prism 21. Since the prism 22 and the curved lens 23 are common in practical applications and easy to process, the manufacturing cost can be saved while achieving the same optical effect.

[0096] In the above two embodiments, no matter it is the curved prism 21 or the composite lens composed of the prism 22 and the curved lens 23, their light incident surfaces 21A face the lighting module 1, and the light path emitted from the lighting module 1 enters the curved prism 21 via the light incident surface 21A of the curved prism 21, and the light path is reflected to the curved surface 21C via the reflection-transmission composite interface 21B of the curved prism 21, and then reflected back to the reflection-transmission composite interface 21B via the curved surface 21C, and finally the light path is emitted into the light modulation module 4 via the reflection-transmission composite interface 21B.

[0097] Figure 5A and 5B FIG. 8 shows a multi-faceted reflecting prism 81 in an optical system according to an embodiment of the present invention, and the multi-faceted reflecting prism 81 is used to receive and reflect the light path focused and shaped by the camera lens 7. Figure 5A As shown, the multi-faceted reflective prism 81 includes a light incident surface 81A, a light emitting surface 81B, a first reflective surface 81C, and a second reflective surface 81D. Figure 5B As shown, the first reflecting surface 81C and the second reflecting surface 81D are coated with a reflecting film for reflecting the light path, thereby changing the direction of the light path in the multi-faceted reflecting prism 81.

[0098] A first angle is formed between the light incident surface 81A and the first reflection surface 81C, a second angle is formed between the first reflection surface 81C and the second reflection surface 81D, and a third angle is formed between the second reflection surface 81D and the light emitting surface 81B. In a preferred embodiment, the first angle is 15° to 75°, the second angle is 15° to 150°, and the third angle is 15° to 90°. In a most preferred embodiment, the first angle is 45°, the second angle is 60°, and the third angle is 45°. The above numerical ranges are obtained by the inventors of the present application after multiple experiments, and the technical effects are enhanced successively.

[0099] Return to Figure 2 Since the scanning reflector 6, the camera lens 7 and the multifaceted reflective prism 81 are arranged in sequence along the reflection direction of the light path, the light path focused and shaped by the camera lens 7 enters the multifaceted reflective prism 81 via the light incident surface 81A of the multifaceted reflective prism 81, and the light path is reflected via the first reflective surface 81C to the second reflective surface 81D, and then reflected by the second reflective surface 81D to the light emitting surface 81B, and finally leaves the multifaceted reflective prism 81 from the light emitting surface 81B of the reflective prism 81 and enters the image sensor module 9.

[0100] By using the multi-faceted reflective prism 81 to replace the second reflector 8 in the prior art, the propagation direction of the light path in the prior art can be changed, so that the light path emitted from the multi-faceted reflective prism 81 is more concentrated toward the middle of the oral digital impression device. Figure 6 As shown, the optical system according to the present invention is located Figure 6Above, the optical system in the prior art is located Figure 6 By comparison, it can be known that the image sensor module in the optical system according to the present invention can be arranged radially inwardly of the optical system, so that the image sensor module can be arranged between the projection lens and the camera lens, which is further conducive to the integrated arrangement of various modules in the optical system, reduces the size of the optical system in the radial direction, is easy to hold and operate, and is conducive to the miniaturization of the oral digital impression instrument.

[0101] In order to illustrate the miniaturization of the optical system for the oral digital impression device of the present invention, Figure 7 A schematic diagram showing a comparison between an optical system according to an embodiment of the present invention and an optical system of the prior art is shown, wherein the optical system according to the embodiment of the present invention is located at Figure 7 Above, the prior art optical system is located Figure 7 In actual use, the optical system needs to be enclosed in a housing so that the operator can hold it for operation.

[0102] like Figure 7 As shown, the radial dimension of the optical system in the prior art is H2, and the space occupied in the radial direction is relatively large. Compared with the prior art, the optical system according to the present invention uses a curved prism to replace the combination of the reflector and the lens in the prior art, so that the illumination module, the curved prism, the light modulation module and the projection lens are roughly distributed in a straight line, thereby reducing the radial space occupied by the optical path emission subsystem. In addition, since the multi-faceted reflecting prism in the optical system according to the present invention is used to replace the second reflector in the prior art, the reflected light path can be reflected radially toward the inside of the optical system, so that the image sensor module can be arranged radially toward the inside of the optical system, and further, the image sensor module can be arranged between the camera lens and the projection lens. The radial space occupied by the optical system is further reduced, which is beneficial to reduce the radial size of the outer shell enclosing the optical system, which facilitates the holding operation. As shown Figure 7 As shown, the radial distance H1 of the optical system according to the embodiment of the present invention is significantly smaller than the radial distance H2 of the optical system in the prior art.

[0103] The present invention also provides an image acquisition method implemented using the optical system according to the present invention. Figure 8 As shown, the method comprises the following steps:

[0104] The illumination module 1 generates a monochromatic or polychromatic light path, which enters the curved prism 21 through the light incident surface 21A of the curved prism 21;

[0105] After the light path enters the curved prism 21, it is incident on the light-emitting surface 21B of the curved prism 21, and is reflected from the light-emitting surface 21B to the curved surface 21C. Since the curved surface 21C is coated with a reflective film, the light path is reflected from the curved surface 21C to the light-emitting surface 21B again, and is emitted to the light modulation module 4 at the incident angle required by the light modulation module 4;

[0106] After receiving the light path, the light modulation module 4 controls the reflector array in the digital micromirror element 41 through a DMD controller 42, so that the light path carries specific pattern information and finally emits it to the projection lens 5;

[0107] The light path with pattern information is received by the projection lens 5 and projected to the scanning reflector 6 via the projection lens 5;

[0108] The scanning reflector 6 reflects the light path with the pattern information to the target object, that is, the oral cavity or the area to be collected 100 in the oral cavity;

[0109] The image of the target object is directed to the camera lens 7, which focuses and shapes the light path including the image directed by the scanning reflector 6, and finally projects the light to the multi-faceted reflective prism 81 via the multi-faceted reflective prism (81);

[0110] The image of the target object enters the multi-faceted reflection prism 81 through the light incident surface 91A of the multi-faceted reflection prism 81, is reflected by the first reflection surface 81C to the second reflection surface 81D, and is reflected by the second reflection surface 81D to the light emitting surface 81B, and finally enters the image sensor module 9;

[0111] The image sensor module 9 receives and processes the image of the area to be collected 100 in the oral cavity.

[0112] The implementation of the present invention is not limited to the above-described embodiments, and can also be adjusted and optimized according to different design requirements and use environments. The protection scope of the present invention shall be based on the content of the claims, and is not limited to the above-described embodiments. Although the present invention has been described by specific embodiments, those skilled in the art, without departing from the spirit of the present invention, make various modifications, changes and combinations of the various embodiments and implementation methods of the present invention, which should be within the scope of the present invention.

Claims

1. An optical system, comprising: An optical path emission subsystem, the optical path emission subsystem generates an optical path with pattern information and emits the optical path into a target object; A scanning reflector (6), the scanning reflector (6) being used to reflect the light path with pattern information into the target object and derive an image in the target object; as well as an image receiving and processing subsystem, the image receiving and processing subsystem receiving and processing the image derived by the scanning reflector (6), Wherein, the optical path transmitting subsystem comprises: An illumination module (1), wherein the illumination module (1) generates a light path; A light modulation module (4), wherein the light modulation module (4) causes the light path to carry the pattern information; and A curved prism (21) is arranged between the lighting module (1) and the light modulation module (4), wherein the curved prism (21) comprises a light incident surface (21A), a reflection-transmission composite interface (21B), and a curved surface (21C) coated with a reflection film, and the curved prism (21) is used to change the direction of the light path and focus the light path; the light path enters from the light incident surface (21A), is reflected by the reflection-transmission composite interface (21B), is then reflected and focused by the curved surface (21C), and then is emitted from the reflection-transmission composite interface (21B) and enters the light modulation module (4) at a specific angle.

2. The optical system according to claim 1, wherein: The reflection-transmission composite interface (21B) is formed with a light-transmitting surface and a reflection surface, the incident angle of the light path transmitted from the light-incident surface (21A) to the reflection-transmission composite interface (21B) is greater than the critical angle of total reflection of the curved prism (21), and the incident angle of the light path reflected from the curved surface (21C) and focused to the reflection-transmission composite interface (21B) is less than the critical angle of total reflection of the curved prism (21).

3. The optical system according to claim 1, wherein: The curved surface (21C) of the curved prism (21) is a light path converging curved surface, and the light path reflected from the reflection-transmission composite interface (21B) to the curved surface (21C) is focused and then reflected back to the reflection-transmission composite interface (21B).

4. The optical system according to claim 1, wherein: The curved prism (21) is implemented as a composite lens composed of a triangular prism (22) and a curved lens (23), and the curved lens (23) constitutes the curved surface (21C) of the curved prism (21).

5. The optical system according to claim 1, wherein: The optical path emission subsystem further comprises a projection lens (5), and the projection lens (5) is used to project the optical path with pattern information onto the scanning reflector (6).

6. The optical system according to claim 5, characterized in that In the light path emission subsystem, the lighting module (1), the curved prism (21), the light modulation module (4) and the projection lens (5) are arranged in sequence along the emission direction of the light path.

7. The optical system according to claim 1, wherein: The image receiving and processing subsystem comprises: A camera lens (7), wherein the camera lens (7) focuses and shapes the light path including the image derived from the scanning reflector (6); an image sensor module (9), the image sensor module (9) being used to process the image derived by the scanning reflector (6); and A multifaceted reflection prism (81) is arranged between the camera lens (7) and the image sensor module (9), and is used to receive and reflect a focused and shaped light path, wherein the multifaceted reflection prism (81) comprises a light incident surface (81A), a light exiting surface (81B), a first reflection surface (81C), and a second reflection surface (81D), and the first reflection surface (81C) and the second reflection surface (81D) are coated with a reflection film, and the light path is incident on the first reflection surface (81C) via the light incident surface (81A), and is reflected by the first reflection surface (81C) to the second reflection surface (81D), and then is reflected by the second reflection surface (81D) to the light exiting surface (81B), and then is emitted from the light exiting surface (81B).

8. The optical system according to claim 7, characterized in that A first angle is formed between the light incident surface (81A) and the first reflection surface (81C), a second angle is formed between the first reflection surface (81C) and the second reflection surface (81D), and a third angle is formed between the second reflection surface (81D) and the light emitting surface (81B).

9. The optical system according to claim 8, characterized in that The first angle is 15° to 75°, the second angle is 15° to 150°, and the third angle is 15° to 90°.

10. The optical system according to claim 9, characterized in that The first angle is 45°, the second angle is 60°, and the third angle is 45°.

11. The optical system according to claim 7, wherein: In the image receiving and processing subsystem, the camera lens (7), the multi-faceted reflection prism (81) and the image sensor module (9) are arranged in sequence along the reflection direction of the light path.

12. An oral digital impression device equipped with the optical system according to any one of claims 1 to 11.

13. The oral digital impression device according to claim 12, characterized in that: The target object is the oral cavity (100).

14. An image acquisition method comprising the following steps: Using the optical system according to any one of claims 1 to 11, the illumination module (1) generates a light path, and the light path is incident on the light modulation module (4) at a specific angle via the curved prism (21); The light modulation module (4) receives the light path and makes the light path carry pattern information; The projection lens (5) receives the light path with pattern information and projects it to the scanning reflector (6); The scanning reflector (6) reflects the light path with pattern information into the target object, and exports the image in the target object to the camera lens (7); The camera lens (7) focuses and shapes the light path including the image derived from the scanning reflector (6), and emits the light to the image sensor module (9) via the multi-faceted reflective prism (81); The image sensor module (9) processes the image.

Images