阅读说明：本技术 结构光模块、三维扫描装置及方法以及电子装置 (Structured light module, three-dimensional scanning device and method and electronic device ) 是由 谈智伟 许哲源 黎康熙 蔡雄宇 于 2019-11-14 设计创作，主要内容包括：本发明涉及一种三维扫描装置及其结构光模块,转动第一光学组件可改变原始光斑的传播方向,从而使发射器的视场角发生变化,第二光学组件同步转动则可保证接收器能够接收到反射光斑。随着第一光学组件转动,发射器会依次从多个不同的视场角投射出原始光斑,而接收器按预设频率接收则可获取多组反射光斑。每组反射光斑与对应的原始光斑比对均可得到一组待测物体的点云。通过将多组点云叠加,便可获得待测物体的三维信息。由于待测物体的三维信息最终由多组点云叠加得到,故每组点云内允许存在部分缺失。因此,发射器的发射功率可相应缩小,能效可得到提升。此外,本发明还提供一种三维扫描方法、电子装置。(The invention relates to a three-dimensional scanning device and a structural optical module thereof.A first optical component is rotated to change the propagation direction of an original light spot, so that the field angle of a transmitter is changed, and a second optical component synchronously rotates to ensure that a receiver can receive a reflected light spot. With the rotation of the first optical assembly, the emitter can project original light spots from a plurality of different field angles in sequence, and the receiver can obtain a plurality of groups of reflected light spots after receiving according to a preset frequency. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the transmitting power of the transmitter can be correspondingly reduced, and the energy efficiency can be improved. In addition, the invention also provides a three-dimensional scanning method and an electronic device.)

1. A structured light module, comprising:

a transmitter;

the original light spot emitted by the emitter can be projected to an object to be measured through the first optical component;

a receiver; and

the original light spot can penetrate through the second optical component through reflected light spots formed by the reflection of the object to be detected, and the reflected light spots are received by the receiver;

the first optical assembly and the second optical assembly can synchronously rotate around a first rotating shaft and a second rotating shaft which are parallel to each other respectively so as to change the propagation directions of the original light spot and the reflected light spot.

2. The structured light module of claim 1, wherein the original light spot and the reflected light spot are reflected in the first optical assembly and the second optical assembly, respectively.

3. The structural optical module of claim 1, wherein the first optical component and the second optical component are both prisms, two side surfaces of the first optical component respectively constitute a first incident surface and a first exit surface, and the first rotation axis is parallel to the first incident surface and the first exit surface and perpendicular to a central axis of the emitter; two side surfaces of the second optical component respectively form a second incident surface and a second emergent surface, and the second rotating shaft is parallel to the second incident surface and the second emergent surface and is vertical to the central axis of the receiver.

4. The architectural optical module of claim 3, wherein the first incident surface is perpendicular to the first exit surface, the second incident surface is perpendicular to the second exit surface, the transmitting end of the transmitter is disposed opposite to the receiving end of the receiver, the first optical assembly and the second optical assembly are located between the transmitter and the receiver, and the first incident surface faces the transmitting end of the transmitter, and the second exit surface faces the receiving end of the receiver.

5. The structural light module of claim 4, wherein the first optical assembly comprises a first reflection surface connecting the first incident surface and the first exit surface and parallel to the first rotation axis, the first reflection surface being located inside the first optical assembly; the second optical assembly comprises a second reflecting surface which is connected with the second incident surface and the second emergent surface and is parallel to the second rotating shaft, and the second reflecting surface is positioned inside the second optical assembly.

6. The structural optical module of claim 2, wherein the first optical assembly and the second optical assembly are reflective sheets, the first rotation axis is parallel to the reflective surface of the first optical assembly and perpendicular to the central axis of the transmitter, and the second rotation axis is parallel to the reflective surface of the second optical assembly and perpendicular to the central axis of the receiver.

7. The architectural optical module of claim 1, further comprising a driving member, wherein the driving member is configured to drive the first optical assembly to rotate around the first rotation axis and the second optical assembly to rotate around the second rotation axis.

8. A three-dimensional scanning device, comprising:

the structured light module of any one of claims 1 to 7; and

and the processor is electrically connected with the receiver and used for controlling the receiver to receive the reflected light spots according to a preset frequency and comparing the reflected light spots with the original light spots so as to acquire the three-dimensional information of the object to be detected.

9. The three-dimensional scanning device according to claim 8, wherein the processor is further configured to boost a frequency at which the receiver receives the reflected light spot when a field angle of the transmitter is within a preset range of viewing angles.

10. A three-dimensional scanning method, comprising the steps of:

projecting original light spots to the surface of an object to be measured in sequence in a variable field angle;

receiving reflected light spots formed by the original light spots through the reflection of the object to be detected according to a preset frequency to obtain a plurality of groups of reflected light spots;

and comparing the original light spots with the multiple groups of reflected light spots respectively to acquire the three-dimensional information of the object to be detected.

11. The three-dimensional scanning method according to claim 10, wherein the step of receiving the reflected light spots formed by the original light spots reflected by the object to be measured at a preset frequency to obtain a plurality of groups of the reflected light spots further comprises:

and when the angle of field projected by the original light spot is within a preset visual angle range, improving the frequency of receiving the reflected light spot.

12. An electronic device, comprising a three-dimensional scanning device according to claim 8 or 9.

Technical Field

The present invention relates to the field of optical measurement technologies, and in particular, to a structured light module, a three-dimensional scanning device and method, and an electronic device.

Background

Structured light technology is a common measurement mode in the field of non-contact optical three-dimensional measurement. The structured light technology has the advantages of low cost, high precision and the like, so that the structured light technology is widely applied. The structured light technology adopts the principle that a transmitter transmits light spots with specific patterns to an object, then a camera receives light spot pattern codes reflected by the surface of the object, and finally the three-dimensional coordinates of the object are calculated by utilizing the principle of triangulation.

However, the existing structured light module has several drawbacks when applied to 3D reconstruction. For example, the scanning accuracy is not high, and point cloud distortion exists. In order to make the scanning accuracy meet the requirement, a mode of enhancing the transmitting power of the transmitter is generally adopted, and this in turn causes the energy efficiency of the structured light module to be low.

Disclosure of Invention

Accordingly, it is necessary to provide a structural optical module, a three-dimensional scanning device and method, and an electronic device with high energy efficiency, which solve the problem of low energy efficiency of the conventional structural optical module.

A structured light module comprising:

a transmitter;

the original light spot emitted by the emitter can be projected to an object to be measured through the first optical component;

a receiver; and

the original light spot can penetrate through the second optical component through reflected light spots formed by the reflection of the object to be detected, and the reflected light spots are received by the receiver;

the first optical assembly and the second optical assembly can synchronously rotate around a first rotating shaft and a second rotating shaft which are parallel to each other respectively so as to change the propagation directions of the original light spot and the reflected light spot.

According to the optical module with the structure, the propagation direction of the original light spot can be changed by rotating the first optical assembly, so that the field angle of the emitter is changed, and the reflected light spot can be received by the receiver by synchronously rotating the second optical assembly. With the rotation of the first optical assembly, the emitter can project original light spots from a plurality of different field angles in sequence, and the receiver can obtain a plurality of groups of reflected light spots after receiving according to a preset frequency. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the transmitting power of the transmitter can be correspondingly reduced, and the energy efficiency can be improved.

In one embodiment, the original spot and the reflected spot are reflected within the first optical assembly and the second optical assembly, respectively.

Only the propagation path of the light rays is changed due to the reflection. Therefore, through reflection, deformation of the original light spot and the reflected light spot in the transmission process can be effectively avoided, and the measurement accuracy of the optical module with the structure is ensured.

In one embodiment, the first optical component and the second optical component are both prisms, two side surfaces of the first optical component respectively form a first incident surface and a first exit surface, and the first rotation axis is parallel to the first incident surface and the first exit surface and is perpendicular to the central axis of the emitter; two side surfaces of the second optical component respectively form a second incident surface and a second emergent surface, and the second rotating shaft is parallel to the second incident surface and the second emergent surface and is vertical to the central axis of the receiver.

The prism can be integrally formed by optical materials such as glass, resin and the like, so that the structures of the first optical assembly and the second optical assembly are more reliable.

In one embodiment, the first incident surface is perpendicular to the first emergent surface, the second incident surface is perpendicular to the second emergent surface, the transmitting end of the transmitter is opposite to the receiving end of the receiver, the first optical assembly and the second optical assembly are located between the transmitter and the receiver, the first incident surface faces the transmitting end of the transmitter, and the second emergent surface faces the receiving end of the receiver.

That is, the projection path of the original light spot can be changed by 90 degrees, and the reflected light spot can also be deflected by 90 degrees after passing through the second optical assembly, so as to be successfully received by the receiver. Thus, a "periscopic" layout of the structural light modules can be achieved. The transmitter and the receiver are generally in the shape of a strip, and the transmitting end and the receiving end are respectively located at the ends of the transmitter and the receiver in the longitudinal direction. By utilizing the 'periscopic' layout, the transmitting end and the receiving end are oppositely arranged, so that the transmitter and the receiver can be transversely arranged on the same straight line, the structure of the structural optical module can be compact, and the thickness of the structural optical module can be reduced.

In one embodiment, the first optical assembly includes a first reflection surface connecting the first incident surface and the first exit surface and parallel to the first rotation axis, the first reflection surface being located inside the first optical assembly; the second optical assembly comprises a second reflecting surface which is connected with the second incident surface and the second emergent surface and is parallel to the second rotating shaft, and the second reflecting surface is positioned inside the second optical assembly.

When light enters the first optical assembly and the second optical assembly, the light can be reflected inside the first optical assembly and the second optical assembly. Therefore, when the original light spot and the reflected light spot respectively pass through the first optical assembly and the second optical assembly, only the transmission path is changed, and the shape is not changed, so that the measurement accuracy of the structural optical module is ensured.

In one embodiment, the first optical component and the second optical component are reflective sheets, the first rotation axis is parallel to the reflective surface of the first optical component and perpendicular to the central axis of the transmitter, and the second rotation axis is parallel to the reflective surface of the second optical component and perpendicular to the central axis of the receiver.

The reflector plate is of a sheet structure, so that the thicknesses of the first optical assembly and the second optical assembly are smaller, and the thickness of the optical module with the structure is favorably reduced.

In one embodiment, the optical module further comprises a driving member, wherein the driving member is used for driving the first optical assembly to rotate around the first rotating shaft and driving the second optical assembly to rotate around the second rotating shaft.

A three-dimensional scanning device comprising:

a structured light module as described in any of the above preferred embodiments; and

and the processor is electrically connected with the receiver and used for controlling the receiver to receive the reflected light spots according to a preset frequency and comparing the reflected light spots with the original light spots so as to acquire the three-dimensional information of the object to be detected.

According to the three-dimensional scanning device, the propagation direction of the original light spot can be changed by rotating the first optical assembly, so that the field angle of the emitter is changed, and the reflected light spot can be received by the receiver by synchronously rotating the second optical assembly. With the rotation of the first optical assembly, the emitter can project original light spots from a plurality of different field angles in sequence, and the receiver can obtain a plurality of groups of reflected light spots after receiving according to a preset frequency. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the transmitting power of the transmitter can be correspondingly reduced, and the energy efficiency can be improved.

In one embodiment, the processor is further configured to increase a frequency at which the receiver receives the reflected light spot when a field angle of the transmitter is within a preset field angle range.

The emitter presets the field angle of the visual angle range, and the original light spots are concentrated to correspond to the specific area of the surface of the object to be measured. Due to the fact that the sampling frequency of the receiver is improved, more reflected light spots reflected by the specific area can be obtained, and therefore more groups of point cloud data of the specific area can be obtained. The reconstruction of this specific area is made finer due to the increased density of the point cloud.

A three-dimensional scanning method, comprising the steps of:

projecting original light spots to the surface of an object to be measured in sequence in a variable field angle;

receiving reflected light spots formed by the original light spots through the reflection of the object to be detected according to a preset frequency to obtain a plurality of groups of reflected light spots;

and comparing the original light spots with the multiple groups of reflected light spots respectively to acquire the three-dimensional information of the object to be detected.

The original light spots can be projected to an object to be measured from a plurality of different field angles in sequence, and a plurality of groups of reflected light spots can be obtained by receiving according to a preset frequency. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the scanning precision of the three-dimensional scanning method can be effectively improved.

In one embodiment, the step of receiving, at a preset frequency, reflected light spots formed by the original light spots reflected by the object to be measured to obtain a plurality of groups of reflected light spots further includes:

and when the angle of field projected by the original light spot is within a preset visual angle range, improving the frequency of receiving the reflected light spot.

An electronic device, comprising the three-dimensional scanning device according to any one of the above preferred embodiments.

Drawings

FIG. 1 is a block diagram of a structured light module according to a preferred embodiment of the present invention;

FIG. 2 is a schematic view illustrating a change in an angle of view of the optical module shown in FIG. 1;

FIG. 3 is a flow chart of a three-dimensional scanning method according to a preferred embodiment of the invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, the present invention provides a structural optical module 100. In addition, the present invention further provides a three-dimensional scanning device (not shown) and an electronic device (not shown). The three-dimensional scanning apparatus includes a processor (not shown) and a structural optical module 100.

By means of the three-dimensional scanning device, the electronic device can scan the surface of the object to be detected, so that three-dimensional data of the surface of the object to be detected can be obtained, and 3D reconstruction is achieved. The structured light module 100 can be applied to the fields of mapping, biological recognition, and the like. For example, the face recognition and fingerprint recognition are widely applied in access control systems and handheld terminals. Correspondingly, the electronic device can be a laser three-dimensional scanner or a mobile phone with a face recognition function or a fingerprint recognition function. For a cell phone, the processor may be a CPU.

Referring to fig. 1 and 2, a structural optical module 100 in a preferred embodiment of the invention includes a transmitter 110, a first optical element 120, a receiver 130, and a second optical element 140. The processor is electrically connected to the transmitter 110 and the receiver 130, respectively.

The emitter 110 is used to emit the original light spot to the object to be measured. The original light spot has a specific shape, such as a rectangle, an ellipse, a triangle, and the like. Under the control of the processor, the emitter 110 may project an original spot of a predetermined shape. The original light spot emitted from the emitter 110 can enter the first optical assembly 120, and is finally projected on the object to be measured after being transferred by the first optical assembly 120.

The first optical element 120 can change the propagation path of the light by means of light refraction, light reflection, or a combination of light refraction and reflection, thereby changing the projection path of the original light spot. Further, the first optical element 120 is rotatable about a first rotation axis (not shown). When the first optical assembly 120 rotates, the incident angle of the original light spot will change, and the propagation direction of the original light spot will be finally changed. Therefore, as the first optical assembly 120 rotates, the field of view (FOV) of the emitter 110 will not be fixed, but will change accordingly.

Referring to fig. 2, the first optical element 120 is configured such that the emitter 110 corresponds to a field angle at each specific angle. As the first optical assembly 120 continues to rotate, the angle of view of the emitter 110 will move with it, covering a larger range.

For example, the first optical element 120 may be rotated within plus or minus 5 degrees relative to the initial position. Correspondingly, the field angle of the emitter 110 will also vary continuously within a range of plus or minus 5 degrees from the field angle of the initial position.

The receiver 130 is used for receiving a reflected light spot formed by reflecting the original light spot by the object to be measured. The second optical element 140 and the first optical element 120 may have the same structure and function. The reflected light spot may pass through the second optical assembly 140 and be received by the receiver 130.

Like the first optical element 120, the second optical element 140 can also change the propagation direction of the reflected light spot by means of light refraction, light reflection, or a combination of light refraction and reflection. Further, the second optical element 140 can rotate around the second rotation axis synchronously with the first optical element 120. Moreover, the second rotating shaft is parallel to the first rotating shaft. When the second optical assembly 140 rotates, the angle of view received by the receiver 130 is also changed to match the angle of view changed by the emitter 110, so that the receiver 130 can always receive the reflected light spot reflected by the original light spot.

To improve the reliability of the structural optical module 100, the transmitter 110, the first optical element 120, the receiver 130 and the second optical element 140 may be packaged in a housing. In this embodiment, the structural optical module 100 further includes a driving member (not shown) for driving the first optical assembly 120 to rotate around the first rotation axis and driving the second optical assembly 140 to rotate around the second rotation axis. In this case, the driving member may be enclosed in the housing.

It should be noted that the driving member may not be included in the structural optical module 100, and the driving mechanism inherent in the three-dimensional scanning device may be used to realize driving. For example, when the optical module 100 is applied to a handheld terminal, the driving part of the optical module 100 may be replaced by a voice coil motor for zooming by a camera.

The processor is configured to control the receiver 130 to receive the reflected light spot at a predetermined frequency. Specifically, when the three-dimensional scanning device scans the object to be measured, the receiver 130 does not receive the reflected light spot in real time, but obtains the reflected light spot in a sampling manner. As the first optical element 120 rotates, the transmitter 110 sequentially projects original light spots from a plurality of different angles of view, and the receiver 130 receives light spots at a predetermined frequency to obtain a plurality of sets of reflected light spots.

For example, it is still assumed that the rotation range of the first optical element 120 is plus or minus 5 degrees. Also, the preset frequency is set to "sample 1 time per 1 degree of rotation". Then, during the rotation of the first optical assembly 120, the receiver 130 may perform 10 sampling, and finally 10 sets of reflected light spots may be collected.

Further, the processor is also used for comparing the reflected light spot with the original light spot to acquire the three-dimensional information of the object to be detected. Specifically, by comparing the change of the reflected light spot relative to the original light spot, the three-dimensional information of the object to be measured can be calculated by utilizing the principle of triangulation, and 3D reconstruction is completed. Moreover, multiple times of sampling can obtain multiple reflection light spots, so that point cloud data of a group of objects to be detected can be obtained by comparing each group of reflection light spots with corresponding original light spots. And the complete three-dimensional information of the object to be detected can be obtained by superposing a plurality of groups of point cloud data.

Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point cloud data, the scanning precision does not depend on the completeness of the single group of point cloud data. That is, even if some group or groups of point cloud data have partial loss, the final scanning precision is not affected. Accordingly, the transmission power of the transmitter 110 may be reduced accordingly.

In this embodiment, the processor is further configured to raise the frequency at which the receiver 130 receives the reflected light spot when the field angle of the emitter 110 is within the preset field angle range.

Specifically, the sampling frequency of the reflected light spot by the receiver 130 is not kept constant, but can be adjusted according to the position of the field angle of the emitter 110. The emitter 110 presets the field angle of the view angle range, and the original light spots are concentrated to correspond to a specific area on the surface of the object to be measured. Due to the increased sampling frequency of the receiver 130, more reflected light spots reflected by the specific area can be obtained, thereby obtaining more sets of point cloud data of the specific area. The reconstruction of this specific area is made finer due to the increased density of the point cloud.

The surface of the object to be measured may have dense-feature regions and sparse-feature regions. The dense feature region refers to a region with a complex surface structure and a large distribution of feature points. The characteristic sparse region refers to a region with a flat surface, a simple structure and less distribution of characteristic points. Taking a human face as an example, the triangular region is relatively three-dimensional and complex in structure due to the fact that the triangular region is uneven, and therefore the triangular region is considered as a characteristic dense region of the human face; the forehead is similar to a plane, and the structure is relatively simple, so the forehead can be regarded as a characteristic sparse region of the face.

Obviously, for a feature dense region, denser point cloud data is needed to achieve fine 3D reconstruction. Therefore, the preset viewing angle range may be set, so that when the viewing angle of the emitter 110 is within the preset viewing angle range, the projection direction of the original light spot is exactly focused on the feature dense region on the surface of the object to be measured, thereby implementing a fine 3D reconstruction of the feature dense region.

For example, it is still assumed that the rotation range of the first optical element 120 is plus or minus 5 degrees. When the human face is scanned, the triangular area is found to be concentrated in the rotation range of plus or minus 1 degree of the field angle of the emitter 110. Accordingly, plus or minus 1 degree may be set as "preset viewing angle range", and the sampling frequency of the receiver 130 is increased from "1 sample per rotation of 1 degree" to "1 sample per rotation of 0.2 degree". Therefore, when the projection direction of the original light spot is just concentrated in the triangular area, 10 groups of point cloud data can be obtained, and the 3D reconstruction precision of the human face triangular area is effectively improved.

Further, in this embodiment, the processor is further configured to determine the preset viewing angle range according to the interaction operation of the user.

Specifically, the position of a specific region (generally referred to as a feature dense region) varies on the surface of different objects to be measured. Therefore, the preset visual angle range is adjusted in real time according to the interactive operation of the user, the preset visual angle range can be ensured to always correspond to the specific area of the surface of the object to be measured, and the 3D reconstruction precision is ensured.

For example, the user can select a specific area of the object to be detected through a mobile phone screen interface. Further, the processor receives the interactive operation of the user and converts the interactive operation into angle information to obtain the preset visual angle range. It should be noted that, in other embodiments, the three-dimensional scanning device may also automatically identify the boundary of the specific area of the object to be scanned, and cause the processor to automatically generate the preset viewing angle range.

As mentioned above, the first optical element 120 and the second optical element 140 can change the propagation routes of the original light spot and the reflected light spot by reflecting, refracting or both reflecting and refracting the light. In the present embodiment, the original light spot and the reflected light spot are reflected in the first optical element 120 and the second optical element 140, respectively.

Specifically, the light reflection includes a case of total reflection. The first optical element 120 and the second optical element 140 may be single reflectors, a combination of reflectors arranged according to a predetermined rule, or a lens with a total reflection surface. Only the propagation path of the light rays is changed due to the reflection. Therefore, by reflection, the original light spot and the reflected light spot can be effectively prevented from being deformed in the propagation process, so as to ensure the measurement accuracy of the optical module 100 with the above structure.

In the present embodiment, the first optical element 120 and the second optical element 140 are prisms. Two side surfaces of the first optical element 120 respectively form a first incident surface and a first exit surface, and the first rotation axis is parallel to the first incident surface and the first exit surface and perpendicular to the central axis of the emitter 110. The two side surfaces of the second optical element 140 respectively form a second incident surface and a second exit surface, and the second rotation axis is parallel to the second incident surface and the second exit surface and perpendicular to the central axis of the receiver 130.

Specifically, the original light spot enters the first optical assembly 120 through the first incident surface, and is projected to the object to be measured through the first exit surface. The generated reflected light spot enters the second optical assembly 140 from the second incident surface and enters the receiver 130 through the second exit surface. The original light spots and the reflected light spots can change the propagation direction after refraction, reflection or total reflection in the prism. When the first optical element 120 and the second optical element 140 rotate around the first rotation axis and the second rotation axis, respectively, the incident angles of the original light spot and the reflected light spot can be changed, and the propagation directions of the original light spot and the reflected light spot can be changed.

Since the prism can be integrally formed by optical materials such as glass and resin, the structures of the first optical element 120 and the second optical element 140 can be more reliable.

It should be noted that in other embodiments, the first optical assembly 120 and the second optical assembly 140 may also be an optical device such as a lens, a prism, etc., or a combination thereof, as long as the light transmission is realized. Such as:

in another embodiment, the first optical element 120 and the second optical element 140 are reflective sheets, the first rotation axis is parallel to the reflective surface of the first optical element 120 and perpendicular to the central axis of the transmitter 110, and the second rotation axis is parallel to the reflective surface of the second optical element 120 and perpendicular to the central axis of the receiver 130.

The original light spot and the reflected light spot are reflected on the reflecting surfaces of the first optical assembly 120 and the second optical assembly 140, respectively, to change the propagation direction. Moreover, since the reflective sheet has a sheet structure, the thicknesses of the first optical assembly 120 and the second optical assembly 140 are small, which is beneficial to reducing the thickness of the structural optical module 100.

Further, in the present embodiment, the first incident surface is perpendicular to the first emergent surface, the second incident surface is perpendicular to the second emergent surface, the transmitting end of the transmitter 110 is disposed opposite to the receiving end of the receiver 130, the first optical element 120 and the second optical element 140 are disposed between the transmitter 110 and the receiver 130, the first incident surface faces the transmitting end of the transmitter 110, and the second emergent surface faces the receiving end of the receiver 130.

The first incident plane is perpendicular to the first emergent plane, which means that the projection path of the original light spot after passing through the first optical assembly 120 can be changed by 90 degrees; similarly, the second incident surface is perpendicular to the second emergent surface, which means that the reflected light spot incident perpendicularly can also be deflected by 90 degrees after passing through the second optical assembly 140, so as to be received by the receiver successfully. Therefore, a "periscopic" layout of the structural optical module 100 can be achieved.

The transmitter 110 and the receiver 130 are generally in the shape of long bars, and the transmitting end and the receiving end are respectively located at the ends of the transmitter 110 and the receiver 130 in the longitudinal direction. Therefore, by using the "periscopic" layout, the transmitter and the receiver are arranged opposite to each other, so that the transmitter 110 and the receiver 130 can be transversely arranged on the same straight line, and the structure of the structural optical module 100 can be compact, which is beneficial to reducing the thickness thereof.

Further, in the present embodiment, the first optical assembly 120 includes a first reflection surface (not shown) connected to the first incident surface and the first exit surface and parallel to the first rotation axis, and the first reflection surface is located inside the first optical assembly 120; the second optical assembly 140 includes a second reflection surface (not shown) connected to the second incident surface and the second exit surface and parallel to the second rotation axis, and the second reflection surface is located inside the second optical assembly 140.

The light entering the first optical element 120 and the second optical element 140 will be reflected therein. Therefore, when the original light spot and the reflected light spot respectively pass through the first optical assembly 120 and the second optical assembly 140, only the transmission path is changed without changing the shape, thereby ensuring the measurement accuracy of the structural optical module 100.

More specifically, the first optical element 120 and the second optical element 140 may be right-angle prisms. Two right-angle surfaces of the first optical component 120 respectively form a first incident surface and a first emergent surface, and the inclined surface forms a first reflecting surface; the two right-angle surfaces of the second optical element 120 respectively form a second incident surface and a second emergent surface, and the inclined surfaces form a second reflecting surface.

In the three-dimensional scanning apparatus and the structural optical module 100, the first optical assembly 120 is rotated to change the propagation direction of the original light spot, so that the field angle of the emitter 110 is changed, and the second optical assembly 140 is rotated synchronously to ensure that the receiver 130 can receive the reflected light spot. As the first optical element 120 rotates, the transmitter 110 sequentially projects original light spots from a plurality of different angles of view, and the receiver 130 receives light spots at a predetermined frequency to obtain a plurality of sets of reflected light spots. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the transmission power of the transmitter 110 can be reduced accordingly, and the energy efficiency can be improved.

Referring to fig. 3, the present invention further provides a three-dimensional scanning method, which includes steps S210 to S230:

and step S210, projecting original light spots to the surface of the object to be measured in sequence in the changed field angle.

Specifically, the original light spot has a specific shape, such as a rectangle, an ellipse, a triangle, and the like. According to the requirement, the original light spot with the preset shape can be projected to the object to be measured. The field angle represents the projection direction of the original light spot, namely the original light spot is projected to the surface of the object to be measured from different angles.

Step S220, receiving the reflected light spots formed by the original light spots reflected by the object to be measured according to a preset frequency, and obtaining a plurality of groups of reflected light spots.

Specifically, when three-dimensional scanning is performed, the reflected light spot is acquired in a sampling mode instead of being received in real time. Because the original light spots can be projected to the object to be measured from a plurality of different view field angles in sequence, a plurality of groups of different reflected light spots can be obtained.

Taking the above three-dimensional scanning device as an example, the rotation range of the angle of view is plus or minus 5 degrees. Also, the preset frequency is set to "sample 1 time per 1 degree of rotation". Then, 10 times of sampling is needed during the scanning process, and finally 10 groups of reflected light spots can be acquired.

Step S230, comparing the original light spots with the multiple groups of reflected light spots, respectively, to obtain three-dimensional information of the object to be measured.

Specifically, by comparing the change of the reflected light spot relative to the original light spot, the three-dimensional information of the object to be measured can be calculated by utilizing the principle of triangulation, and 3D reconstruction is completed. Moreover, multiple times of sampling can obtain multiple reflection light spots, so that point cloud data of a group of objects to be detected can be obtained by comparing each group of reflection light spots with corresponding original light spots. And the complete three-dimensional information of the object to be detected can be obtained by superposing a plurality of groups of point cloud data.

Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point cloud data, the scanning precision does not depend on the completeness of the single group of point cloud data. That is, even if some group or groups of point cloud data have partial loss, the final scanning precision is not affected.

In this embodiment, the step S220 further includes: and when the angle of field projected by the original light spot is within the preset range of the angle of field, the frequency of receiving the reflected light spot is increased.

Specifically, the sampling frequency for the reflected light spot is not kept constant, but can be adjusted according to the position of the original light spot projection field angle. When the field angle is within the preset visual angle range, the original light spots are concentrated to correspond to the specific area of the surface of the object to be measured. Due to the fact that sampling frequency is improved, more reflection light spots reflected by the specific area can be obtained, and therefore more groups of point cloud data of the specific area can be obtained. The reconstruction of this specific area is made finer due to the increased density of the point cloud.

The surface of the object to be measured may have dense-feature regions and sparse-feature regions. The dense feature region refers to a region with a complex surface structure and a large distribution of feature points. The characteristic sparse region refers to a region with a flat surface, a simple structure and less distribution of characteristic points. Taking a human face as an example, the triangular region is relatively three-dimensional and complex in structure due to the fact that the triangular region is uneven, and therefore the triangular region is considered as a characteristic dense region of the human face; the forehead is similar to a plane, and the structure is relatively simple, so the forehead can be regarded as a characteristic sparse region of the face.

Obviously, for a feature dense region, denser point cloud data is needed to achieve fine 3D reconstruction. Therefore, the preset visual angle range can be set, when the visual angle projected by the original light spot is within the preset visual angle range, the projection direction of the original light spot is just concentrated in the characteristic dense area of the surface of the object to be measured, and therefore fine 3D reconstruction of the characteristic dense area is achieved.

Still taking the three-dimensional scanning device as an example, the variation range of the angle of view projected by the original light spot is plus or minus 5 degrees. When the human face is scanned, the triangular area is found to be concentrated in the variation range of the field angle of plus or minus 1 degree. Therefore, the range of plus or minus 1 degree is set as the "preset angle of view range", and the sampling frequency is increased from "1 sampling per rotation of 1 degree" to "1 sampling per rotation of 0.2 degree". Therefore, when the projection direction of the original light spot is just concentrated in the triangular area, 10 groups of point cloud data can be obtained, and the 3D reconstruction precision of the human face triangular area is effectively improved.

It should be noted that the "preset viewing angle range" may be set according to user interaction, and may also be configured to automatically identify the boundary of the specific area of the object to be viewed, and automatically generate the preset viewing angle range.

According to the three-dimensional scanning method, the original light spots can be projected to the object to be measured from a plurality of different field angles in sequence, and a plurality of groups of reflected light spots can be obtained by receiving according to the preset frequency. And comparing each group of reflected light spots with the corresponding original light spots to obtain a group of point clouds of the object to be detected. And superposing the multiple groups of point clouds to obtain the three-dimensional information of the object to be detected. Because the three-dimensional information of the object to be detected is finally obtained by superposing a plurality of groups of point clouds, partial deletion is allowed to exist in each group of point clouds. Therefore, the scanning precision of the three-dimensional scanning method can be effectively improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.