Lens, three-dimensional imaging module and three-dimensional imaging device

Abstract

This invention relates to a lens, a 3D imaging module, and a 3D imaging device. The lens has an incident axis and includes a lens element. The lens element includes at least two sub-lenses, each with a non-rotationally symmetric structure. Each sub-lens includes an effective light-transmitting portion. The effective light-transmitting portion of the lens element is rotationally symmetric about the incident axis. The effective light-transmitting portion of the lens element is used to transmit an incident light beam to form mutually separated imaging images on the image side of the lens. The number of imaging images is equal to the number of sub-lenses in the lens element. In the above-described lens, the non-rotationally symmetric structure allows for a reduction in the radial structural size of the sub-lenses, thereby facilitating the placement of two or more sub-lenses within a single lens. This allows for the acquisition of at least two imaging images from different angles of the subject, significantly reducing the lateral size of the 3D imaging system and enabling better 3D imaging in confined spaces.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional imaging technology, and in particular to a lens, a three-dimensional imaging module, and a three-dimensional imaging device. Background Technology

[0002] Traditional 3D imaging typically involves using two or more lenses at different angles to acquire 2D images of the same object from these angles. 3D data is then obtained by comparing and analyzing the information from these 2D images. However, this traditional 3D imaging equipment requires multiple lenses for 3D measurement, resulting in a large structure for mounting the lenses and significant operational limitations. Summary of the Invention

[0003] Therefore, it is necessary to provide a lens, a 3D imaging module, and a 3D imaging device to address the problem of how to acquire 3D imaging information with a small-sized structure.

[0004] A lens has an incident axis and includes a lens element. The lens element includes at least two sub-lenses, each of which is a non-rotationally symmetric structure. Each sub-lens includes an effective light-transmitting portion. Any two effective light-transmitting portions of the lens element are rotationally symmetric about the incident axis. The effective light-transmitting portions of the lens element can transmit an incident light beam to form mutually separated imaging images on the image side of the lens. The number of imaging images is equal to the number of sub-lenses in the lens element.

[0005] In the aforementioned lens, compared to a typical lens with rotational symmetry, the non-rotational symmetry structure allows for a reduction in the radial dimension of the sub-lenses. This enables two or more sub-lenses to be housed within a single lens, allowing for at least two images of the subject from different angles. This significantly reduces the lateral size of the 3D imaging system, enabling a compact design and better 3D imaging in confined spaces. Terminal analysis of features such as depressions and protrusions in each image reveals the corresponding 3D information, including depth and height.

[0006] In one embodiment, each of the sub-lenses in the lens element is formed by dividing a single lens.

[0007] In one embodiment, the lens includes at least two imaging units, each of the imaging units including at least two sub-lenses arranged along the incident axis, each of the sub-lenses being contained within a lens element.

[0008] In one embodiment, the sub-lenses in the same lens element are spaced apart or staggered in a direction perpendicular to the incident axis.

[0009] In one embodiment, the sub-lens includes an arcuate edge that is located away from the incident axis.

[0010] In one embodiment, the lens satisfies any of the following:

[0011] The lens element includes two sub-lenses, and the projection shape of the two sub-lenses on a plane perpendicular to the incident axis is semi-circular along a direction parallel to the incident axis.

[0012] The lens element includes three sub-lenses along a direction parallel to the incident axis, wherein two of the sub-lenses have a fan-shaped projection on a plane perpendicular to the incident axis, and the other sub-lens has a semi-circular projection on a plane perpendicular to the incident axis.

[0013] The lens element includes four sub-lenses, and the projection shape of the four sub-lenses on a plane perpendicular to the incident axis is fan-shaped along a direction parallel to the incident axis.

[0014] In one embodiment, each of the sub-lenses in the lens element surrounds the incident axis.

[0015] In one embodiment, any two of the sub-lenses in the lens element are rotationally symmetrical about the incident axis.

[0016] In one embodiment, the lens includes an aperture, the number of which is the same as the number of sub-lenses in the lens element, and each of the sub-lenses in the lens element overlaps with the projection of one of the apertures onto a plane perpendicular to the incident axis along a direction parallel to the incident axis.

[0017] In one embodiment, any two of the apertures are rotationally symmetrical about the incident axis.

[0018] In one embodiment, the lens includes two apertures, the line connecting the centers of the two apertures being inclined to the line connecting the centroids of the two sub-lenses.

[0019] In one embodiment, the apertures of each aperture are identical.

[0020] A three-dimensional imaging module includes an image sensor and a lens as described above, wherein the image sensor is disposed on the image side of the lens.

[0021] By using the aforementioned lens, the lateral dimension of the 3D imaging module can be effectively reduced, thereby expanding the module's usable space and enabling the 3D imaging module to perform more efficient and flexible 3D imaging in narrow spaces.

[0022] In one embodiment, the number of image sensors is one.

[0023] In one embodiment, the three-dimensional imaging module includes a light source for illuminating the subject.

[0024] A three-dimensional imaging device includes the three-dimensional imaging module described in any of the above claims. The three-dimensional imaging device can be applied in fields such as medical and industrial manufacturing. Due to the small lateral dimension of the three-dimensional imaging module, the three-dimensional imaging device can perform efficient and flexible three-dimensional detection in confined spaces. For example, when the three-dimensional imaging module is installed in the probe of the device, the small size of the module allows for a smaller probe size, thereby improving the probe's operational flexibility in confined spaces. Attached Figure Description

[0025] Figure 1 This includes schematic diagrams of the lens from two different perspectives in one embodiment of this application;

[0026] Figure 2 for Figure 1 A schematic diagram showing the distribution of the image corresponding to the lens;

[0027] Figure 3 This is a schematic diagram of the structure of a three-dimensional imaging module in one embodiment of this application;

[0028] Figure 4 This is a schematic diagram of the structure of a three-dimensional imaging module in another embodiment of this application;

[0029] Figure 5 This is a schematic diagram showing the configuration of the sub-lens and aperture in a lens according to an embodiment of this application;

[0030] Figure 6 for Figure 5 A schematic diagram showing the distribution of the image corresponding to the lens;

[0031] Figure 7 This is a schematic diagram illustrating the configuration of the sub-lens and aperture in a lens according to another embodiment of this application;

[0032] Figure 8 for Figure 7 A schematic diagram showing the distribution of the image corresponding to the lens;

[0033] Figure 9 This is a schematic diagram illustrating the configuration of the sub-lens and aperture in a lens according to another embodiment of this application;

[0034] Figure 10 This is a schematic diagram of the lens element of a lens in another embodiment of this application;

[0035] Figure 11 for Figure 10 A schematic diagram showing the distribution of the image corresponding to the lens;

[0036] Figure 12 This is a schematic diagram of the lens element of a lens in another embodiment of this application;

[0037] Figure 13 This is a schematic diagram of the lens element of a lens in another embodiment of this application;

[0038] Figure 14 for Figure 13 A schematic diagram showing the distribution of the image corresponding to the lens;

[0039] Figure 15 This is a schematic diagram of the structure of a three-dimensional imaging module in one embodiment of this application;

[0040] Figure 16 This is a partial structural schematic diagram of a three-dimensional imaging device provided in an embodiment of this application. Detailed Implementation

[0041] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0047] Traditional 3D imaging typically involves using two or more lenses at different angles to acquire two-dimensional images of the same object from these angles. The 3D data is then obtained by comparing and analyzing the information from these two-dimensional images. However, this traditional 3D imaging equipment is relatively large and has significant operational limitations.

[0048] See Figure 1Some embodiments of this application provide a lens 10. The lens 10 has positive optical power and is used to converge the image information of the subject onto the imaging surface 103. The lens 10 includes a lens barrel 100 and a lens element 110 with an irregular structure. The lens element 110 is installed inside the lens barrel 100. The object end of the lens barrel 100 has an entrance aperture 1001. The central axis of the entrance aperture 1001 is collinear with the incident axis 101 of the lens 10, and the imaging surface 103 of the lens 10 is perpendicular to the incident axis 101. The imaging surface 103 can be the photosensitive surface of an image sensor.

[0049] In these embodiments, the lens element 110 includes two sub-lenses spaced apart from each other in a direction perpendicular to the incident axis 101. Both sub-lenses are non-rotationally symmetric structures, meaning they lack any axis of symmetry such that any sub-lens can be rotated by an angle θ (0 < θ < 360°) around the axis of symmetry and still coincide with the unrotated sub-lens. The two sub-lenses are centrally symmetric about the incident axis 101, and the two centrally symmetric sub-lenses have identical structures; for example, the object-side surface and image-side surface of the two sub-lenses are identical. Along the direction parallel to the incident axis 101, the projection shapes of the two sub-lenses onto the imaging plane 103 are identical semicircles, and the two sub-lenses can be translated and joined together to form a complete lens in the direction perpendicular to the incident axis 101. On the other hand, the sub-lens includes an arc-shaped edge 1107, which is far from the incident axis 101. If the two semi-circular sub-lenses are spliced ​​together to form a complete lens, the arc-shaped edges 1107 of the two sub-lenses will serve as the effective light-transmitting edges of the object side or image side of the lens.

[0050] Specifically, the two sub-lenses can be formed by equally dividing a complete lens. The dividing path passes through and is parallel to the optical axis of the lens. The cut surfaces of the two sub-lenses after division are planar and remain parallel to each other. The two sub-lenses are spaced apart along a direction perpendicular to the optical axis of the lens. The complete lens has positive optical power, and the object-side surface and image-side surface of the lens can be spherical or aspherical. Therefore, when divided into two sub-lenses, the object-side and image-side surfaces of the sub-lenses will also have corresponding surface shapes.

[0051] exist Figure 1In the illustrated embodiments, each sub-lens can form an imaging unit, and each imaging unit corresponds to an imaging image. After the incident light beam is adjusted by each imaging unit, it can form an imaging image on the imaging surface 103 of the lens 10, with the number of imaging units being the same. Each sub-lens includes an effective light-transmitting portion 1101. Specifically, both the object-side and image-side surfaces of any sub-lens include an effective light-transmitting portion 1101, and any two effective light-transmitting portions 1101 in the same lens element 110 are rotationally symmetrical about the incident axis 101. For an incident light beam that can pass through a sub-lens to form a corresponding imaging image on the imaging surface, the area traversed by the incident light beam in the sub-lens is the effective light-transmitting portion 1101 of that sub-lens. In some embodiments, any two sub-lenses in the same lens element 110 are rotationally symmetrical about the incident axis 101. Furthermore, in some embodiments, the rotational symmetry angle between two effective light-transmitting portions 1101 in the same lens element 110 about the incident axis 101 can be, but is not limited to, 60°, 90°, 120°, or 180°. Specifically, when the two effective light-transmitting parts 1101 are 180° rotationally symmetrical about the incident axis 101, that is, when the two effective light-transmitting parts 1101 are centrally symmetrical about the incident axis 101.

[0052] The spacing between the sub-lenses can separate the imaging images on the imaging surface 103, thereby enabling three-dimensional analysis of the corresponding features in the two imaging images at the system terminal.

[0053] For reference Figure 2When the lens element 110 in lens 10 is a single, complete lens, the subject, after being converged by the lens, can form an original image 104 on the imaging surface 103 of lens 10. However, when the lens element 110 is divided into two spaced-apart sub-lenses as described in the above embodiment, the incident light beam will form a new image on the imaging surface 103 after passing through each sub-lens. The two new image images can represent different angles of the same subject area. The original image 104 on the imaging surface 103 will gradually separate into two new image images as the distance between the sub-lenses increases. When two sub-lenses are translated a certain distance in one direction and can be stitched together to form a single, complete lens, this distance can be called the distance between the two sub-lenses. The separation direction of the image images depends partly on the direction in which the sub-lenses move away from the incident axis 101. For example, taking an undivided, single lens as a reference, when the lens is divided into two spaced-apart sub-lenses in one direction relative to the incident axis 101, the image images corresponding to the two divided sub-lenses will also separate in that direction. When the distance between the sub-lenses is large enough, the two new imaging images will be completely separated and will not overlap, resulting in a gap between them. Subsequently, by performing terminal analysis on the features such as depressions and convexities in the two spaced imaging images, the three-dimensional information such as the depth and height of the corresponding features can be obtained. Terminal analysis methods include, but are not limited to, binocular ranging methods.

[0054] In the design of the above embodiment, it is only necessary to separate the sub-lenses in the lens 10 along a direction perpendicular to the incident axis 101 to create an interval between the two new imaging images. Thus, two imaging images of the subject from different angles can be obtained through a single lens 10. Compared to a typical lens with a rotationally symmetric structure, the non-rotationally symmetric structure allows for a reduction in the radial structural size of the sub-lenses, enabling two or more sub-lenses to be housed within a single lens. Furthermore, compared to designs with two or more lenses 10, the single-lens 10 design significantly reduces the lateral size of the 3D imaging system, enabling a smaller-sized design. This also helps to reduce the size of the structure used to mount the lens 10 in the 3D imaging device, allowing for better 3D imaging in confined spaces. For example, when the lens 10 is mounted in the probe of an endoscope, since only one lens 10 is needed to acquire 3D information, the size of the probe can be effectively reduced, thereby improving the probe's operational flexibility in confined spaces.

[0055] Continue to refer to Figure 1In some embodiments, the lens 10 includes an aperture, which can be integrally formed with the lens barrel 100. The number of apertures is the same as the number of sub-lenses in the lens element 110, and each sub-lens in the same lens element 110 corresponds one-to-one with an aperture, wherein each sub-lens and aperture together constitute an imaging unit. Along the direction parallel to the incident axis 101, the projections of each sub-lens and its corresponding aperture on the imaging plane 103 overlap. In addition, any two apertures are centrally symmetrical about the incident axis 101 of the lens 10, and the apertures of each aperture are the same, thereby ensuring that the brightness and size of the image formed by each imaging unit tend to be consistent, which is beneficial to the accuracy of terminal analysis. In addition to being centrally symmetrical, any two apertures in some embodiments can also be set in other rotationally symmetrical ways, depending on the setting of the sub-lenses in the lens element 110. The aperture can also be used to limit edge beams, suppress spherical aberration caused by edge beams, and control the depth of field of the image. In other embodiments, the aperture is relatively independent of the lens barrel 100, in which case the aperture can be assembled together with the lens element 110 when it is installed into the lens barrel 100. Figure 1 In the illustrated embodiment, the two sub-lenses are a first sub-lens 1111 and a second sub-lens 1112, and the two apertures are a first aperture 121 and a second aperture 122. The first aperture 121 is disposed on the image side of the first sub-lens 1111, and the second aperture 122 is disposed on the image side of the second sub-lens 1112. The line connecting the centers of the first aperture 121 and the second aperture 122 is perpendicular to the incident axis 101 and along a direction parallel to the incident axis 101, the projections of the first sub-lens 1111 and the first aperture 121 on the imaging plane 103 overlap, and the projections of the second sub-lens 1112 and the second aperture 122 on the imaging plane 103 also overlap.

[0056] Reference Figure 2The first sub-lens 1111 and the first aperture 121 constitute the first imaging unit 1021, and the second sub-lens 1112 and the second aperture 122 constitute the second imaging unit 1022. Correspondingly, the two separate imaging images are the first imaging image 1051 and the second imaging image 1052, respectively. The first imaging unit 1021 corresponds to the first imaging image 1051, and the second imaging unit 1022 corresponds to the second imaging image 1052. The incident light beam enters the lens 10 through the light entrance aperture 1001 of the lens barrel 100, and after being adjusted and converged by the first imaging unit 1021, the first imaging image 1051 is formed on the imaging surface 103. After being adjusted and converged by the second imaging unit 1022, the second imaging image 1052 is formed on the imaging surface 103. For a recessed or protruding feature on the subject, the corresponding images of the recess and protrusion in the imaging image will exhibit different degrees of blurring. Furthermore, the first imaging unit 1021 and the second imaging unit 1022, spaced apart, can image the feature at different angles, thus enabling the lens 10 to also possess binocular vision. By performing terminal analysis on the same feature in the first imaging image 1051 and the second imaging image 1052—for example, analyzing the blurring of the feature image and / or the distance between the feature images in the two images—the depth information of the feature structure can be obtained. Using the lens 10 in the above embodiment, three-dimensional imaging information can be reconstructed from the two-dimensional imaging information of the subject, thereby achieving three-dimensional imaging of the subject.

[0057] In other embodiments, the first aperture 121 may be disposed on the object side of the first sub-lens 1111, and the second aperture 122 may be disposed on the object side of the second sub-lens 1112, with the center line connecting the first sub-lens 1111 and the second sub-lens 1112 still perpendicular to the incident axis 101. The symmetrical arrangement of the sub-lenses and apertures about the incident axis 101 helps improve the consistency of brightness, sharpness, and size of the image, thereby improving the accuracy of terminal analysis.

[0058] In addition, to prevent incident light beams other than the first sub-lens 1111 and the second sub-lens 1112 from reaching the image sensor, in some embodiments, the lens 10 also includes a light-blocking plate 130. The light-blocking plate 130 is connected between the sub-lenses in the lens element 110, and the light-blocking plate 130 is opaque. The light-blocking plate 130 can be a metal plate or a plastic plate, and the light-blocking plate 130 can be arranged perpendicular to the incident axis 101. A black coating can be provided on the light-blocking plate 130 to prevent the incident light beam from being reflected by the light-blocking plate 130 and forming stray light in the lens 10. By connecting the sub-lenses, the light-blocking plate 130 can also increase the installation stability between the sub-lenses.

[0059] refer to Figure 3 , Figure 3An embodiment provides a three-dimensional imaging module 20, which includes an image sensor 210 and, in the embodiments described above, a lens 10. The image sensor 210 is disposed on the image side of the lens 10. The image sensor 210 can be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) element. The imaging surface 103 of the lens 10 overlaps with the photosensitive surface of the image sensor 210, and the incident axis 101 of the lens 10 is perpendicular to the photosensitive surface and passes through the center of the photosensitive surface. The light beam from the object being photographed is converged by the lens 10 and can form two mutually spaced imaging images on the photosensitive surface of the image sensor 210. In particular, when there is only one image sensor 210, each imaging image can be formed on the image sensor 210, thereby effectively controlling the lateral size of the module and further realizing the small-size design of the three-dimensional imaging module 20.

[0060] The photosensitive surface on the image sensor 210 is generally rectangular. In some embodiments, the separation direction of each sub-lens is parallel to the length direction of the photosensitive surface, and the spacing between the sub-lenses along this parallel direction is greater than or equal to half the length of the photosensitive surface. This facilitates the formation of two separate imaging images on the photosensitive surface. The aforementioned spacing between the sub-lenses can be understood as the minimum distance between two sub-lenses along the parallel direction. Furthermore, the spacing between the sub-lenses along this parallel direction should be less than or equal to three-quarters of the length of the photosensitive surface to prevent image quality degradation caused by excessively large spacing between the sub-lenses.

[0061] As described above, by employing the lens 10, the lateral dimension of the 3D imaging module 20 can be effectively reduced, thereby expanding the usable space of the module and enabling the 3D imaging module 20 to perform more efficient and flexible 3D imaging in narrow spaces. It should be noted that, in addition to setting only one image sensor 210, the 3D imaging module 20 can also be equipped with two or more image sensors 210, with each image sensor 210 corresponding to one or two imaging images.

[0062] On the other hand, to prevent interfering light from reaching the imaging surface 103, the 3D imaging module 20 also includes a filter. The filter is located between the lens 10 and the image sensor 210, or it can be located on the object side of the lens 10, such as covering the light entrance aperture 1001 of the lens barrel 100. Both of these can be considered as the filter being located on the object side of the image sensor 210. Depending on the wavelength of the working light, the filter can be a visible light bandpass filter or an infrared bandpass filter. Generally, in methods for reconstructing a 2D image into a 3D image, there are corresponding analysis methods for imaging within a range of wavelengths or a specific wavelength band. When the 3D imaging module 20 can perform 3D reconstruction of visible light imaging, the filter in the module can be an infrared cutoff filter, thereby filtering out infrared light and preventing infrared light from interfering with visible light imaging.

[0063] In some embodiments, the 3D imaging module 20 includes a light source, which is fixedly disposed relative to the lens 10. The light source is used to illuminate the subject, and a filter is used to allow light of a wavelength emitted by the light source to pass through. The lens 10 receives the light that is illuminating the subject and reflected back by the light source to form a corresponding image on the image sensor 210. Specifically, in one embodiment, when the 3D imaging module 20 needs to image a specific wavelength band (such as 900nm infrared light), the 3D imaging module 20 may additionally provide an infrared light source to illuminate the subject with 900nm infrared light. In this case, the filter can be a narrow-bandpass filter for 900nm, thereby filtering out incident light beams with wavelengths other than 900nm. In other embodiments, a filter may not be provided; instead, a filter film may be provided on the object-side and / or image-side of the sub-lens to achieve a filtering effect. In addition to illuminating infrared light of this wavelength, the light source in some embodiments may also illuminate infrared light of other wavelengths, or may illuminate monochromatic visible light.

[0064] It should be noted that the arrangement of each sub-lens and each aperture is not limited to the scheme mentioned in the above embodiments. See also... Figure 4In some embodiments, the axial direction 1102 of each sub-lens is tilted relative to the incident axis 101. For each sub-lens with this tilted configuration, the object-side surface of the sub-lens is closer to the incident axis 101 than the image-side surface. When two sub-lenses are joined together to form a single lens, the axial direction 1102 of the sub-lens is parallel to the optical axis of that lens. In some embodiments, the angle between the axial direction 1102 of the sub-lens and the incident axis 101 of the lens 10 is 1° to 20°. The tilted sub-lenses can increase the spacing between each image frame, meaning that each sub-lens can create a spacing relationship between its corresponding image frames with a smaller spacing, thereby facilitating a further reduction in the lateral size of the lens 10. Furthermore, by controlling the tilt angle, it is also beneficial to avoid excessively large spacing between image frames, which could cause areas containing feature information on each image frame to exceed the imaging range of the image sensor 210. Similarly, the aperture corresponding to the sub-lens is also tilted synchronously with the corresponding sub-lens, and the central axis of the tilted aperture is parallel to the axial direction 1102 of the corresponding sub-lens, thereby ensuring uniform brightness across the image frame. The tilt settings of each sub-lens and aperture can also be understood as the overall tilt settings of the corresponding imaging units. When the structures of each imaging unit are the same or nearly the same, each imaging unit should also be rotationally symmetrical about the incident axis 101 after being tilted about the incident axis 101.

[0065] On the other hand, the specific setting of the aperture can be varied and is not limited to... Figure 1 The displayed setup options are for comparison. Figure 1 and Figure 5 ,exist Figure 1 In the illustrated embodiment, the line connecting the centers of the two apertures is parallel to the separation direction of the two sub-lenses; while Figure 5 In the illustrated embodiment, the line connecting the centers of the two apertures is inclined to the line connecting the centroids of the two sub-lenses. Depending on the position of the apertures, the position of the corresponding image will also change. This can be further illustrated in conjunction with... Figure 5 and Figure 6 , Figure 6 It reflects Figure 5 The arrangement of the imaging images corresponding to lens 10 in the embodiment. Figure 6 The box in the figure represents the photosensitive surface of the image sensor 210. The separation direction between the sub-lenses is parallel to the length direction of the photosensitive surface. When the direction of the line connecting the centers of the aperture is tilted to the separation direction of the two sub-lenses, the two imaging images will also be displaced in the direction tilted to the length direction after being separated along the length direction. That is, the two imaging images will be arranged at intervals along the diagonal direction of the photosensitive surface. This can improve the utilization rate of the photosensitive surface and increase the imaging interval of the same features on the subject on the imaging surface 103, thereby improving the accuracy of the reconstructed three-dimensional information.

[0066] In addition to the interval setting method, the sub-lenses in the lens element 10 can also obtain interval imaging images by staggering their positions. (See reference...) Figure 7 In some embodiments, two sub-lenses capable of being joined to form a complete lens are offset in a direction perpendicular to the incident axis 101. The two offset sub-lenses remain in contact, and when the two sub-lenses are moved in the opposite direction along the offset direction, the two sub-lenses can be rejoined to form a complete lens. (See also...) Figure 8 By using a misalignment setting, the separation distance between two new imaging images increases as the misalignment distance between the two sub-lenses increases, and the separation direction of the two new imaging images partially depends on the misalignment direction of the two sub-lenses. In an embodiment of the misalignment setting, when two sub-lenses can be stitched together into a complete lens after being translated a certain distance in one direction, this distance can be called the misalignment distance between the two sub-lenses.

[0067] In the embodiments of this application, when describing the spacing or misalignment of the sub-lenses in the same lens element 110, it can be referred to as the separation of the sub-lenses. That is, separation does not necessarily mean that the corresponding sub-lenses are spaced apart; they can also be misaligned in a contacting state. The separation direction between sub-lenses represents the spacing direction or misalignment direction between the sub-lenses.

[0068] On the other hand, the positional relationship between the aperture and the sub-lens also determines the separation direction and separation distance of the two new imaging images. In some embodiments, each sub-lens is configured with an aperture to form an imaging unit, and the two apertures are spaced apart in a plane perpendicular to the incident axis 101. In these embodiments, the apertures in the two imaging units are spaced apart in a direction perpendicular to the misalignment direction and the incident axis 101, and the size of this spaced distance directly affects the separation distance of the two new imaging images in that direction. Therefore, it is precisely because Figure 7 In this embodiment, the first sub-lens 1111 and the second sub-lens 1112 are misaligned in the misalignment direction, and the corresponding first aperture 121 and second aperture 122 are spaced apart in the direction perpendicular to the misalignment direction. Therefore, the two new images on the imaging plane 103 are separated in both the parallel and perpendicular directions of the misalignment direction, thus exhibiting... Figure 8 The case shown is the separation along the diagonal.

[0069] exist Figure 7 In the illustrated embodiment, along a direction parallel to the incident axis 101, the projections of the first aperture 121 and the first sub-lens 1111 onto the imaging plane 103 share an axis of symmetry, and the projections of the second aperture 122 and the second sub-lens 1112 onto the imaging plane 103 also share an axis of symmetry. These two axes of symmetry can be referenced... Figure 7The dashed line in the image has two axes of symmetry that pass through the projection centers of the two apertures, respectively.

[0070] refer to Figure 9 In other embodiments, the first aperture 121 and the second aperture 122 may also be offset from the corresponding axes of symmetry described above. Figure 9 In the illustrated embodiments, as the first aperture 121 and the second aperture 122 move further apart in the misalignment direction, the separation distance between the corresponding first imaging image 1051 and the second imaging image 1052 in that misalignment direction will also further increase. In these embodiments, the first aperture 121 and the second aperture 122 maintain a rotationally symmetrical relationship about the incident axis 101, and both have the same aperture diameter.

[0071] By implementing a spaced and staggered design for the sub-lenses in the lens element 110, and by adjusting the setting position of the aperture, it is possible to flexibly obtain various imaging images arranged and separated in the desired manner. Furthermore, the setting relationships between the sub-lenses and between the apertures are not limited to those described in the above embodiments; any method that can obtain the desired image image through the above setting principles should be included within the scope of this application.

[0072] Furthermore, the number of sub-lenses in lens element 110 can be three, four, or more, in addition to the two shown in the above embodiments. In this case, each sub-lens is still housed within a lens barrel, and each sub-lens can also be formed by dividing a single lens, with each divided sub-lens having a non-rotationally symmetric structure. Compared to lenses with multiple complete lenses, each sub-lens in the above design has a smaller radial dimension relative to a complete lens, allowing it to be installed within a single lens, reducing the lateral dimension of the module, and the incident light beam can still form a separate imaging image after passing through the sub-lenses.

[0073] For specific details, please refer to Figure 10 In some embodiments, the lens element 110 includes four sub-lenses. Along a direction parallel to the incident axis 101, the projection shape of the four sub-lenses onto the imaging plane 103 is fan-shaped. The four sub-lenses are spaced apart from each other, and their surface shapes are identical. The four sub-lenses are rotationally symmetrical about the incident axis 101 of the lens 10; in some embodiments, they may be centrally symmetrical. When the four sub-lenses are moved close to the incident axis 101, they can be joined to form a complete lens. Specifically, a complete lens can be equally divided into four sub-lenses, with the dividing path passing through and parallel to the central axis of the lens. Then, the four sub-lenses are translated the same distance radially from the original lens. After the translation, the four sub-lenses, fixed by the lens barrel 100, belong to one lens element 110, which is rotationally symmetrical about the incident axis 101.

[0074] exist Figure 10 In the illustrated embodiment, lens 10 further includes four apertures, each corresponding to a sub-lens. Each pair of corresponding sub-lenses and apertures constitutes an imaging unit. Specifically, lens 10 includes four imaging units: a first imaging unit 1021, a second imaging unit 1022, a third imaging unit 1023, and a fourth imaging unit 1024. The first imaging unit 1021 includes a first sub-lens 1111 and a first aperture 121; the second imaging unit 1022 includes a second sub-lens 1112 and a second aperture 122; the third imaging unit 1023 includes a third sub-lens 1113 and a third aperture 123; and the fourth imaging unit 1024 includes a fourth sub-lens 1114 and a fourth aperture 124. The imaging units are spaced apart and symmetrical about the incident axis 101. Within the same imaging unit, the projections of the sub-lenses and apertures onto the imaging plane 103 overlap. As can be seen from the above embodiment containing two sub-lenses, the spacing of each sub-lens and aperture can separate the corresponding imaging images, and the separation direction and distance depend on the spacing direction and spacing distance between each sub-lens, as well as the setting position of each aperture.

[0075] Therefore, refer to Figure 10 and Figure 11 The light beam from the subject within the depth of field of lens 10, after being adjusted by the first imaging unit 1021, can form a clear first image 1051 on the imaging surface 103. After passing through the second imaging unit 1022, it can form a second image 1052. After passing through the third imaging unit 1023, it can form a third image 1053. After passing through the fourth imaging unit 1024, it can form a fourth image 1054. Figure 10 In the illustrated embodiment, the four imaging units are symmetrically located radially away from the incident axis 101. Since the incident axis 101 passes through the center of the imaging surface 103, the four imaging images will also move away from the center of the imaging surface 103 along the direction of the corresponding imaging unit away from the incident axis 101, and finally form four separate images.

[0076] Similarly, in addition to the spacing, adjacent sub-lenses can also be staggered to separate the imaging images, thus forming four spaced imaging images.

[0077] For details, please refer to [link / reference]. Figure 12In this embodiment, each of the four sub-lenses is offset from the other two, and the four sub-lenses are rotationally symmetrical about the incident axis 101. When the lens element 110 is rotated 90°, 135°, or 180° about the incident axis 101, the same structure is still obtained, and the resulting image remains unchanged. In this embodiment, the offset sub-lenses abut against each other, thereby increasing the stability of the lens element 110 within the lens barrel 100.

[0078] On the other hand, the lens element 110 can also be formed with respect to the incident axis 101 without rotational symmetry, thereby increasing the versatility of the lens 10 design.

[0079] refer to Figure 13 and Figure 14 In some embodiments, the lens element 110 includes three sub-lenses: a first sub-lens 1111, a second sub-lens 1112, and a third sub-lens 1113. Along a direction parallel to the incident axis 101, the projection shapes of the first sub-lens 1111 and the second sub-lens 1112 on the imaging plane 103 are the same sector shape, and the projection shape of the third sub-lens 1113 on the imaging plane 103 is a semi-circle. The projected area of ​​the third sub-lens 1113 is the sum of the projected areas of the first sub-lens 1111 and the second sub-lens 1112. The first sub-lens 1111, the second sub-lens 1112, and the third sub-lens 1113 can be formed by dividing a single lens; the dividing path can be referenced. Figure 13 The three sub-lenses, after being divided, are each translated radially by the same distance relative to the incident axis 101 to be fixed in the lens barrel 100, thereby forming a lens element 110. Correspondingly, the lens 10 also includes three apertures, namely a first aperture 121, a second aperture 122, and a third aperture 123. Specifically, in order to maintain the consistency of the depth of field and brightness of the image, in some embodiments, the first aperture 121, the second aperture 122, and the third aperture 123 have the same aperture diameter.

[0080] The first sub-lens 1111 and the first aperture 121 form the first imaging unit 1021; the second sub-lens 1112 and the second aperture 122 form the second imaging unit 1022; and the third sub-lens 1113 and the third aperture 123 form the third imaging unit 1023. (Reference) Figure 14 The light beam from the object within the depth of field of the lens 10, after being adjusted by the first imaging unit 1021, can form a clear first image 1051 on the imaging surface 103. After passing through the second imaging unit 1022, it can form a second image 1052, and after passing through the third imaging unit 1023, it can form a third image 1053. (Reference) Figure 13In contrast, when a conventional lens is used in lens 10, the optical axis of the conventional lens is collinear with the incident axis 101 of lens 10 and passes through the center of the imaging plane 103. In this case, the image formed by the incident beam through lens 10 is... Figure 14 The image shown is a single original image 104 located at the center of the imaging plane 103. And... Figure 13 In the illustrated embodiment, the three imaging units are symmetrically located radially away from the incident axis 101. Since the incident axis 101 passes through the center of the imaging surface 103, the three imaging images will also move away from the center of the imaging surface 103 in the corresponding directions, and eventually form three separate images.

[0081] The above embodiments mainly describe the case where the lens 10 has one lens element 110. However, in some embodiments, in addition to having one lens element 110, the lens 10 may also have at least two lens elements 110, in which case a corresponding number of images can still be obtained on the imaging plane 103. The number of lens elements 110 in the lens 10 can be two, three, four, five or more, and each lens element 110 is arranged sequentially along the direction of the incident axis 101. In these embodiments, the lens 10 still includes a lens barrel 100, and each lens element 110 is disposed within the lens barrel 100. The sub-lenses in each lens element 110 can be formed by dividing different lenses, and for a lens 10 having two or more lens elements 110, the structure of the lens 10 can be regarded as being equally divided from a lens group that can be practically applied to a product, such lens group including but not limited to telephoto lens group, wide-angle lens group, macro lens group, etc.

[0082] In the embodiments of this application, the number of sub-lenses in each lens element 110 is the same. Each sub-lens in lens element 110 corresponds to one sub-lens in each of the other lens elements 110, and each group of corresponding sub-lenses constitutes an imaging unit. Along the direction parallel to the incident axis 101, the projections of the sub-lenses in the same imaging unit onto the imaging plane 103 overlap. In particular, in some embodiments, any two adjacent sub-lenses in any imaging unit can be spaced apart from each other, or they can be formed into a cemented structure.

[0083] It should be noted that in some embodiments, each sub-lens in at least one lens element 110 is coated with a light-shielding film. The light-shielding film is disposed on the object side and image side of the sub-lens, and a light-transmitting area is reserved on the object side and image side of the sub-lens respectively. The area on the object side and image side of the sub-lens corresponding to the light-transmitting area is the effective light-transmitting part 1101 of the corresponding sub-lens. At this time, the size of the effective light-transmitting part 1101 can control the brightness and depth of field of the image, and the distance between the effective light-transmitting parts 1101 on different sub-lenses can also play a role in controlling the separation of the image.

[0084] In other embodiments, an aperture can also be provided in the lens 10 to achieve the above effect. In this case, the number of apertures is the same as the number of sub-lenses in the lens element 110, and they correspond one-to-one. In these embodiments, each imaging unit includes one aperture. Along the direction parallel to the incident axis 101, the projections of the sub-lenses and apertures in the same imaging unit onto the imaging plane 103 overlap.

[0085] For details, please refer to [link / reference]. Figure 15 In one embodiment of this application, the lens 10 includes five lens elements 110, each lens element 110 including two sub-lenses, namely a first sub-lens 1111 and a second sub-lens 1112. The first sub-lens 1111 and the second sub-lens 1112 are formed by equally dividing a complete lens. The shape of the sub-lenses and their separation direction relative to the incident axis 101 can be referenced. Figure 1 The illustrated embodiment. In this embodiment, any first sub-lens 1111 and second sub-lens 1112 in any lens element 110 can be reassembled into a complete lens after being linearly translated along a direction perpendicular to the incident axis 101. The lens 10 also includes a first aperture 121 and a second aperture 122. The first aperture 121 corresponds to each of the first sub-lenses 1111, and the second aperture 122 corresponds to each of the second sub-lenses 1112. Along a direction parallel to the incident axis 101, the projections of each of the first sub-lenses 1111 and the first aperture 121 onto the imaging plane 103 overlap, and the projections of each of the second sub-lenses 1112 and the second aperture 122 onto the imaging plane 103 also overlap. The first aperture 121 and the five first sub-lenses 1111 together form a first imaging unit 1021, and the second aperture 122 and the five second sub-lenses 1112 together form a second imaging unit 1022. The first aperture 121 can be positioned between the first sub-lens 1111 closest to the image side and the image sensor 210, or it can be positioned between any two first sub-lenses 1111, or it can be positioned on the object side of the first sub-lens 1111 furthest from the image sensor 210. The second aperture 122 is positioned similarly. However, it should be noted that in these embodiments, the first imaging unit 1021 and the second imaging unit 1022 should be symmetrical about the incident axis 101 to ensure that the brightness, depth of field, and size of the corresponding images are consistent.

[0086] exist Figure 15In the illustrated embodiment, a five-element lens group can be radially divided into two equal semicircular lens groups, each of which can serve as an imaging unit. This five-element lens group can be a macro lens group, which is beneficial for obtaining excellent imaging at short shooting distances, particularly improving imaging clarity in confined spaces (such as the mouth, intestines, etc.), thereby enhancing the accuracy of 3D reconstruction at short distances.

[0087] You can refer to them together. Figure 2 After being adjusted by the first imaging unit 1021, the incident light beam will form a first imaging image 1051 on the imaging surface 103. After being adjusted by the second imaging unit 1022, the incident light beam will form a second imaging image 1052 on the imaging surface 103. The spacing direction between the first imaging image 1051 and the second imaging image 1052 depends on the spacing direction between the first imaging unit 1021 and the second imaging unit 1022, and also depends on the setting positions of the first aperture 121 and the second aperture 122. The spacing distance between the first imaging image 1051 and the second imaging image 1052 depends on the spacing distance between the first imaging unit 1021 and the second imaging unit 1022, and also depends on the setting positions of the first aperture 121 and the second aperture 122.

[0088] Additionally, in some embodiments, reference may be made to... Figure 5 In the illustrated embodiment, the first imaging unit 1021 and the second imaging unit 1022 may also be tilted to the incident axis 101 in such a way that the axial direction 1102 of the first imaging unit 1021 and the second imaging unit 1022 is tilted to the incident axis 101. In this case, the sub-lens located on the object side in the imaging unit is closer to the incident axis 101 than the sub-lens located on the image side.

[0089] Similarly, besides setting the first sub-lens 1111 and the second sub-lens 1112 at a relative interval, the first sub-lens 1111 and the second sub-lens 1112 can also be set in a staggered manner, for example... Figure 7 The illustrated embodiment, however, requires that the first sub-lens 1111 and the second sub-lens 1112 in each lens element 110 be moved in the same direction and distance to form a staggered arrangement, whereby the staggered first sub-lens 1111 and second sub-lens 1112 remain in contact. Simultaneously, the position of the aperture can be controlled to further separate the image. The aperture configuration can be referenced... Figure 7 and Figure 9 The examples shown are as follows.

[0090] On the other hand, each lens element 110, in addition to including two sub-lenses, may also include, as Figure 10 or Figure 13The illustrated embodiment, i.e., each lens element 110 includes three, four or more sub-lenses, but it should be ensured that the number of sub-lenses in each lens element 110 is the same, and each sub-lens in any lens element 110 corresponds to one sub-lens in each of the other lens elements 110. Each group of corresponding sub-lenses forms an imaging unit, and the number of separated imaging images is equal to the number of imaging units.

[0091] In the above embodiments, each sub-lens in the same lens element 110 can be cut from a single lens.

[0092] In other embodiments, each sub-lens can be fabricated individually, but efforts should be made to ensure that, when each sub-lens is mounted in the lens barrel 100, the effective light-transmitting portions of any two sub-lenses in the same lens element 110 are rotationally symmetrical about the incident axis 101 of the lens 10. Specifically, in one embodiment, the lens element 110 includes a first sub-lens 1111 and a second sub-lens 1112, which are centrally symmetrical about the incident axis 101. In this case, the same spatial distribution structure can be obtained by rotating the lens element 110 180° around the incident axis 101.

[0093] Of course, in some embodiments, the number of sub-lenses is not limited to two, and the overall structure of any two sub-lenses is not limited to being centrally symmetrical about the incident axis 101. They can also be arbitrarily rotationally symmetrical or asymmetrical. However, it should be ensured as much as possible that any two effective light-transmitting parts 1101 in the same lens element 110 have a rotationally symmetrical relationship about the incident axis 101, so as to ensure that the clarity of the image corresponding to each sub-lens tends to be consistent, thereby improving the accuracy of terminal analysis.

[0094] refer to Figure 16 This application also provides a three-dimensional imaging device 30, which may include the three-dimensional imaging module 20 in any embodiment. The three-dimensional imaging device 30 can be applied to fields such as medical and industrial manufacturing. Specifically, the three-dimensional imaging device 30 can be, but is not limited to, smartphones, tablets, dental imaging devices, industrial inspection equipment, drones, and vehicle-mounted imaging devices. Because the lateral dimension of the aforementioned three-dimensional imaging module 20 is small, the three-dimensional imaging device 30 can perform efficient and flexible three-dimensional detection in confined spaces. For example, when the three-dimensional imaging module 20 is placed in the probe of the device, the small size of the module allows the probe to be made even smaller, thereby improving the probe's operational flexibility in confined spaces.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A three-dimensional imaging module comprising a lens for use in a narrow space, having an incident axis, characterized in that, The lens includes a lens element, which includes at least two sub-lenses. Each sub-lens has a non-rotationally symmetric structure and includes an effective light-transmitting portion. Any two effective light-transmitting portions of the lens element are rotationally symmetric about the incident axis. The effective light-transmitting portions of the lens element can transmit an incident light beam to form mutually separated imaging images on the image side of the lens. The number of imaging images is equal to the number of sub-lenses in the lens element. Each sub-lens in the lens element is formed by dividing a lens with positive optical power along a path parallel to the optical axis. The cross-sections of the sub-lenses are planar and parallel to each other. The sub-lenses are spaced apart along a direction perpendicular to the optical axis of the lens to reduce the radial dimension of the lens. The three-dimensional imaging module also includes an image sensor, which is disposed on the image side of the lens, and the number of the image sensor is one. It includes at least two imaging units, each of which includes at least two sub-lenses arranged along the incident axis, and each sub-lens is contained in a lens element; a first sub-lens and a first aperture constitute a first imaging unit, and a second sub-lens and a second aperture constitute a second imaging unit. The two separate imaging images are a first imaging image and a second imaging image, respectively. The first imaging unit corresponds to the first imaging image, and the second imaging unit corresponds to the second imaging image. The incident light beam enters the lens through the light entrance aperture of the lens barrel, and after being adjusted and converged by the first imaging unit, a first imaging image is formed on the imaging surface. After being adjusted and converged by the second imaging unit, a second imaging image is formed on the imaging surface. The separation direction of each sub-lens is parallel to the length direction of the photosensitive surface, and the spacing between sub-lenses in the direction parallel to the length direction is greater than or equal to half the length of the photosensitive surface. In the direction parallel to the length direction, the spacing between sub-lenses should be less than or equal to three-quarters of the length of the photosensitive surface. The lens element includes apertures, the number of which is the same as the number of sub-lenses in the lens element. Along a direction parallel to the incident axis, each sub-lens in the lens element overlaps with the projection of one of the apertures onto a plane perpendicular to the incident axis. Any two apertures are rotationally symmetrical about the incident axis.

2. The three-dimensional imaging module of claim 1, wherein, The sub-lenses in the same lens element are spaced apart or staggered in a direction perpendicular to the incident axis.

3. The three-dimensional imaging module of claim 1, wherein, Any two of the sub-lenses in the lens element are rotationally symmetrical about the incident axis.

4. The three-dimensional imaging module of claim 1, wherein, All the apertures described have the same diameter.

5. The three-dimensional imaging module of claim 1, wherein, The narrow space is a human cavity, including the mouth or intestines.

6. A three-dimensional imaging device, characterized by Includes the three-dimensional imaging module as described in any one of claims 1-5.

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