Imaging system and imaging apparatus

Abstract

An imaging system (100) and an imaging apparatus. The imaging system (100) comprises: a beam splitter (1), which can split a light beam, which is input into the beam splitter (1), into a plurality of light beams in different output directions, and output the light beams; and a plurality of imaging assemblies (2), which correspondingly receive the light beams in the respective output directions, and output electrical signals. Each imaging assembly (2) comprises: a lens (21), which correspondingly receives the light beam in each output direction; and a photosensitive element (22), which correspondingly receives the light beam output by the lens (21) and converts same into an electrical signal, wherein the output direction of the electrical signal output by the photosensitive element (22) is configured to point to an image processor (3). The image distance of an imaging assembly (2) is defined as the distance from the optical center of a lens (21) to a photosensitive element (22), and the focal length of a lens is defined as the distance from the optical center of the lens to a focal point where light converges when parallel light is incident. The plurality of imaging assemblies (2) at least comprise a first imaging assembly (201) corresponding to a first depth of field and a second imaging assembly (202) corresponding to a second depth of field, wherein the values of the first depth of field and the second depth of field are different.

Description

Imaging system and imaging device Technical Field

[0001] This application relates to imaging systems and imaging devices. Background Technology

[0002] For those skilled in the art, cameras are classified into fixed-focus cameras and zoom cameras based on their optical zoom capabilities.

[0003] Zoom cameras can ensure sharpness by adjusting lens structure and the distance between the lens and the image sensor. Due to these factors, they offer significant advantages in image quality and imaging distance, and are widely used in professional photography equipment. However, their disadvantages lie in the complexity of their lens structure and manufacturing process, resulting in relatively high costs.

[0004] Fixed-focus cameras have a fixed distance between the lens and the image sensor, resulting in a fixed shooting area and shooting distance, the latter manifested as a depth-of-field parameter. The depth-of-field parameter reflects the range within which a camera can capture a sharp image; the smaller the focal length and the farther the focusing distance, the greater the corresponding depth-of-field parameter. Due to their fixed depth-of-field parameters, fixed-focus cameras are generally only suitable for shooting a single scene, making them relatively limited in functionality.

[0005] Stereo vision cameras typically use fixed-focus cameras in their visible light displays. This is because the specific internal and external parameters of the camera need to be determined during the calibration process before depth calculation and image registration. With zoom cameras, these parameters change during zooming, making calibration difficult and resulting in poor robustness. Fixed-focus cameras also lack the flexibility of zooming and focusing, leading to a relatively limited depth of field and significantly restricting their applicability. Existing binocular stereo cameras, primarily used indoors, are usually designed with a smaller depth of field, limiting their applications.

[0006] Referring to existing commercial cameras, the inventors discovered that Orbbec's Gemini2 RGB camera, using 1080P resolution, exhibited inaccurate focusing and blurry images within 40cm, while Intel's RealSense D435 camera, also using 1080P resolution, showed inaccurate focusing and blurry images within 30cm. This limited the use of both cameras at close range. Furthermore, at longer distances, when the Gemini2 photographed a calibration board with 20mm cell sizes at 2m, the short focal length resulted in jagged blur. The single RGB camera in commercial cameras, limited by structural constraints, has a limited depth of field, thus restricting its application scenarios.

[0007] Therefore, there is a need in the art for a new imaging system and imaging device to solve one or a combination of the above problems. Summary of the Invention

[0008] The purpose of this application is to overcome the limitation of fixed-focus cameras in applicable scenarios by achieving simple calibration and robust calibration results.

[0009] An imaging system according to a first aspect of this application includes: a beam splitter capable of splitting a light beam input to the beam splitter into multiple light beams with different output directions; multiple imaging components corresponding to receiving the light beams in each output direction and outputting electrical signals, each imaging component including: a lens corresponding to receiving the light beams in each output direction; and a photosensitive element corresponding to receiving the light beams output by the lens and converting them into electrical signals, the output direction of the electrical signals output by the photosensitive element being configured to point to an image processor; wherein, the image distance of the imaging components is defined as the distance from the optical center of the lens to the photosensitive element, and the focal length of the lens is defined as the distance from the optical center of the lens to the focal point where the light converges when parallel light is incident; for the multiple imaging components, at least a first imaging component corresponding to a first depth of field and a second imaging component corresponding to a second depth of field are included, the values ​​of the first depth of field and the second depth of field being different; optionally, the image distance of each imaging component is a fixed value, and the focal length of each lens is a fixed value.

[0010] In one or more embodiments of the imaging system, the plurality of imaging components are configured with a unified optical axis; the image distance of each imaging component is a fixed value, and the focal length of each lens is a fixed value; the fixed focal lengths of the lenses included in different imaging components are different; optionally, the first imaging component includes a first lens with a focal length of a first lens, the second imaging component includes a second lens with a focal length of a second lens, and the fixed values ​​of the focal lengths of the first lens and the second lens are different.

[0011] In one or more embodiments of the imaging system, the plurality of imaging components are configured with a unified optical axis; the image distance of each imaging component is a fixed value, and the focal length of each lens is a fixed value; the fixed focal lengths of the lenses included in different imaging components are the same, but the fixed image distances are different; optionally, the first imaging component includes a first lens and a first photosensitive element, the distance from the optical center of the first lens to the first photosensitive element is the first image distance, and the focal length of the first lens is the first lens focal length; the second imaging component includes a second lens and a second photosensitive element, the distance from the optical center of the second lens to the second photosensitive element is the second image distance, and the focal length of the second lens is the second lens focal length; the fixed values ​​of the first lens focal length and the second lens focal length are the same, but the fixed values ​​of the first image distance and the second image distance are different.

[0012] In one or more embodiments of the imaging system, one or more beam splitters are included; optionally, the imaging system includes multiple beam splitters arranged sequentially in the same direction, the number of beam splitters is N, and the number of the multiple imaging components corresponding to them is N+1, where N is a positive integer greater than or equal to 2; further optionally, the imaging system includes two beam splitters, and the two beam splitters are correspondingly provided with three imaging components.

[0013] In one or more embodiments of the imaging system, the beam splitter is a cuboid, with the long side of the cuboid corresponding to the light-incident surface and the light-exit surface of the beam splitter; or the beam splitter is a cube.

[0014] In one or more embodiments of the imaging system, the beam splitter has a beam-splitting surface, and the beam-splitting surface has a semi-transparent and semi-reflective coating; optionally, the semi-transparent and semi-reflective coating is a visible light coating with a beam splitting ratio of transmission:reflection = 50%:50%; optionally, the reflected light output by the beam splitter corresponds to a first optical axis, and the transmitted light output by the beam splitter corresponds to a second optical axis, wherein the first optical axis is perpendicular to the second optical axis.

[0015] In one or more embodiments of the imaging system, the lens focal length is a fixed value from 0.1 mm to 300 mm; optionally, the lens focal length is a fixed value from 1 mm to 150 mm; more preferably, the lens focal length is a fixed value from 1 mm to 50 mm; further preferably, the lens focal length is a fixed value from 1 mm to 20 mm; even more preferably, the lens focal length is a fixed value from 1 mm to 16 mm; and still more preferably, the lens focal length is a fixed value from 1 mm to 5 mm.

[0016] In one or more embodiments of the imaging system, the photosensitive element is a CCD element or a CMOS element; the imaging assembly is configured as an integrated camera; optionally, the integrated camera is an RGB camera; optionally, the lens of the integrated camera has a lens hood.

[0017] In one or more embodiments of the imaging system, a heat sink is further included, which is fluidly in communication with the beam splitter and / or the plurality of imaging components.

[0018] An imaging apparatus according to a second aspect of this application has an imaging system as described in the first aspect, the imaging apparatus including an indoor monitoring system and a stereo vision industrial camera.

[0019] An imaging method according to a third aspect of this application, employing the imaging system described in the first aspect, the imaging method comprising:

[0020] Multiple imaging components output multiple images corresponding to different depths of field to the image processor, and the image processor fuses the multiple images corresponding to different depths of field to output a fused image;

[0021] Optionally, a first image is output to the image processor via a first imaging component corresponding to a first depth of field;

[0022] The second image is output to the image processor via the second imaging component corresponding to the second depth of field;

[0023] The image processing device fuses the first image and the second image to output a fused image.

[0024] The beneficial effects of the above embodiments include, but are not limited to:

[0025] By configuring the optical path and electrical signal flow of the beam splitter, multiple imaging components, and image processor, images with different depths of field provided by different imaging components can be fused in the image processor. This achieves the advantages of simple calibration and robust calibration results using fixed-focus cameras, while overcoming the limitation of fixed-focus cameras in terms of limited depth of field range, which greatly restricts their applicable scenarios.

[0026] Overview of the attached figures

[0027] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings, wherein:

[0028] Figure 1 is a schematic diagram of the structure of an imaging system according to an embodiment.

[0029] Figure 2 is a schematic diagram of the imaging system according to another embodiment.

[0030] Figure 3 is a schematic diagram of the structure of the beam splitter of an imaging system according to an embodiment.

[0031] Figure 4 is a schematic flowchart of an imaging method according to an embodiment.

[0032] Reference numerals: 100-Imaging system; 1-Beam splitter; 101-First beam splitter; 102-Second beam splitter; 11-Beam splitting surface; 110-Semi-transparent and semi-reflective film; 2-Imaging assembly; 201-First imaging assembly; 202-Second imaging assembly; 203-Third imaging assembly; 21-Lens; 211-First lens; 212-Second lens; 213-Third lens; 22-Photosensitive element; 221-First photosensitive element; 222-Second photosensitive element; 223-Third photosensitive element; 200-Beam; 2001-First beam; 2002-Second beam; 2003-Third beam; 2004-Fourth beam; 2011-First optical axis; 2012-Second optical axis; 3-Image processor; 4-Heat sink.

[0033] Preferred embodiments of the present invention

[0034] The following discloses various implementations or embodiments of the described subject matter. To simplify the disclosure, specific examples of elements and arrangements are described below. These are merely examples and are not intended to limit the scope of protection of the invention. For instance, a first feature formed above or on a second feature, as described later in the specification, can include implementations where the first and second features are formed in a direct connection, or implementations where an additional feature is formed between the first and second features, thus the first and second features may not be directly connected. Furthermore, reference numerals and / or letters may be repeated in different examples in these disclosures. This repetition is for brevity and clarity and does not in itself indicate a relationship between the various implementations and / or structures to be discussed. Further, when the first element is described in connection with or combined with a second element, the description includes implementations where the first and second elements are directly connected or combined with each other, as well as implementations where one or more other intervening elements are added to indirectly connect or combine the first and second elements with each other.

[0035] It is understood that the following flowcharts are used to illustrate the steps performed by the cultivation method according to embodiments of this application. It should be understood that, depending on the actual situation, the preceding or following steps may not necessarily be performed precisely in order. Other steps may be added to these processes, or one or more steps may be removed from them.

[0036] Referring to Figures 1 to 3, the imaging system 100 includes a beam splitter 1 and multiple imaging components 2.

[0037] Beam splitter 1 can split the input beam into multiple beams with different output directions. Multiple imaging components 2 receive the beams in each output direction and output electrical signals.

[0038] It can be understood that the number of beam splitters 1 can be one or more, and the number of imaging components 2 can be at least two.

[0039] For example, as shown in Figure 1, a single beam splitter 1 splits the beam 200 into a first beam 2001 and a second beam 2002. The first beam 2001 is received by the first imaging component 201, and the second beam 2002 is received by the second imaging component 202.

[0040] For example, as shown in Figure 2, there are two beam splitters 1 distributed along the X direction. The first beam splitter 101 splits the beam 200 into a first beam 2001 and a second beam 2002. The first beam 2001 is received by the first imaging component 201, and the second beam 2002 is received by the second beam splitter 102 and split into a third beam 2003 and a fourth beam 2004. The third beam 2003 is received by the second imaging component 202, and the fourth beam 2004 is received by the third imaging component 203.

[0041] It can be understood that the number of beam splitters 1 can be more. That is, in some embodiments, the imaging system 100 includes multiple beam splitters 1, which are arranged sequentially in the same direction. The number of beam splitters 1 is N, and the number of multiple imaging components 2 is N+1, where N is a positive integer greater than or equal to 2.

[0042] Referring to Figure 3, the beam splitter 1 can be a cuboid, with the long side of the cuboid connecting the light-incident surface and the light-exit surface of the beam splitter 1; this avoids obstructing the camera's field of view. Alternatively, the beam splitter 1 can be a cube, and neither is a limitation.

[0043] Referring to Figures 1 to 3, the specific structure for beam splitting by the beam splitter 1 can be as follows: the beam splitter 1 has a beam splitting surface 11, and the beam splitting surface 11 has a semi-transparent and semi-reflective coating 110; optionally, the semi-transparent and semi-reflective coating 110 is a visible light coating with a beam splitting ratio of transmission:reflection = 50%:50%; optionally, the reflected light output by the beam splitter 1 corresponds to the first optical axis 2011, and the transmitted light output corresponds to the second optical axis 2012, with the first optical axis 2011 and the second optical axis 2012 being perpendicular, for example, as shown in Figure 1, the first optical axis 2011 is perpendicular to the second optical axis 2012. One beam 2001 is reflected light, with its first optical axis 2011 along the Y direction. The second beam 2002 is transmitted light, with its second optical axis 2012 along the X direction. The X direction is perpendicular to the Y direction. This design allows for a clearer fused image. By using a semi-reflective beam splitter, the optical axes of cameras with different focal lengths are unified, significantly reducing the baseline length of the two cameras, improving registration accuracy, and ensuring the quality of the final fused image output by the system. It can be understood that the ratio of transmission to reflection can be adjusted according to the needs of the scene, not limited to the aforementioned 50%:50%. Furthermore, the beam splitting structure is not limited to having a semi-reflective coating on the splitting surface; other beam splitting structures are also possible.

[0044] Each imaging component 2 includes: a lens 21, which receives a light beam in each output direction; and a photosensitive element 22, which receives the light beam output by the lens 21 and converts it into an electrical signal. The output direction of the electrical signal output by the photosensitive element 22 is configured to point to the image processor 3.

[0045] The image distance of the imaging component 2 is defined as the distance from the optical center of the lens 21 to the photosensitive element 22, and the focal length of the lens is defined as the distance from the optical center of the lens to the focal point where the light converges when parallel light is incident.

[0046] For multiple imaging components 2, at least a first imaging component 201 corresponding to a first depth of field and a second imaging component 202 corresponding to a second depth of field are included, and the values ​​of the first depth of field and the second depth of field are different.

[0047] The reason for defining image distance and lens focal length is that, in this field, focal length is generally interpreted as a measure of the convergence or divergence of light in an optical system, referring to the distance from the center of the lens to the focal point where light converges. Image distance, on the other hand, is the distance from the optical center of the lens to the imaging plane such as the film, CCD, or CMOS. Therefore, to clearly define the corresponding meanings of image distance and lens focal length, "lens focal length" and "image distance" are defined in this application. Optionally, the image distance of each imaging component 2 is a fixed value, and the lens focal length of each lens 21 is a fixed value.

[0048] It can be understood that lens 21, also known as an optical lens, can include a single lens or a combination of multiple lenses. Each lens 21 has a fixed focal length, generally referred to as a fixed-focus lens. The opposite concept is a zoom lens, which is a camera lens that can change its focal length within a certain range to obtain different field of view angles, image sizes, and scene ranges. For example, optical zoom changes the focal point by moving internal lens elements, thus changing the focal length and the angle of view, thereby magnifying or reducing the image. The fixed image distance of each imaging component 2 and the fixed focal length of each lens 21 mean that the image distance and lens focal length are constant, but different imaging components 2 have different fixed values ​​for their image distance and lens focal length. Specific examples can be found later.

[0049] The photosensitive element 22, also known as an image sensor, utilizes the photoelectric conversion function of an optoelectronic device. It converts the light image on the photosensitive surface into an electrical signal proportional to the light image. Compared to photosensitive elements with "point" light sources such as photodiodes and phototransistors, the photosensitive element is a functional device that divides the light image on its light-receiving surface into many small units and converts them into usable electrical signals. In some embodiments, the photosensitive element 22 can be a CCD (Charge Coupled Device) element; another is a CMOS (Complementary Metal-Oxide Semiconductor) device. A CCD is made of a highly sensitive semiconductor material and consists of many photosensitive units, typically measured in megapixels. When the CCD surface is illuminated, each photosensitive unit reflects a charge onto the component, converting light into charge; the signals generated by all the photosensitive units are added together to form a complete image. This is then converted into a digital signal, compressed, and stored in the camera's internal flash memory or built-in hard drive. CMOS mainly utilizes semiconductors made of silicon and germanium, allowing N-type (negative) and P-type (positive) semiconductors to coexist on the CMOS. The current generated by these two complementary effects can be recorded and interpreted into images by the processing chip.

[0050] In some embodiments, the imaging component 2 is configured as an integrated camera, such as an RGB camera. In some embodiments, the lens 21 of the integrated camera has a lens hood to reduce the impact of prism reflection on image quality.

[0051] For multiple imaging components 2, including at least a first imaging component 201 corresponding to a first depth of field and a second imaging component 202 corresponding to a second depth of field, the values ​​of the first depth of field and the second depth of field are different. As introduced above, the meaning of depth of field here refers to the range of distances including the front and back of the subject that can be captured in a clear image at the front edge of the lens. That is, after focusing, the distance of the clear image presented within the range before and after the focus is completed is called the depth of field. Since the depth of field of the first imaging component 201 and the second imaging component 202 are different, the first image provided by the first imaging component 201 to the image processor 3 and the second image output by the second imaging component 202 to the image processor 3 are different. The image processor 3 can fuse the first image and the second image to output a fused image.

[0052] The specific fusion process can be as follows: For example, camera intrinsic parameter calibration can be performed using MATLAB software, and distortion correction can be achieved using distortion coefficients; simple preprocessing of the image can be performed, the perspective transformation matrix can be calculated, and the images from the two cameras can be registered; pixel-level image fusion can be performed on the registered images from the two cameras, and the final fused image can be output. The advantage of this approach is that by acquiring image data with different focus distances and field of view from various sensors and then performing fusion processing, it is possible to retain a larger range of images captured at a smaller focal length, and to fuse images from different focal lengths to obtain an image with a large depth of field and a wide field of view at the same moment.

[0053] It is understood that the image processor 3 is not limited to a specific processor. For example, in some cases, the image processor 3 can have a distributed structure, such as including processors located at the imaging system end and the back-end cloud, with the image fusion processing described above being implemented by the imaging system end and / or the back-end cloud. Furthermore, in embodiments employing a distributed structure, the specific execution terminal for each step can be adjusted according to actual conditions, and the specific implementation scheme of each step on a particular terminal should not limit the scope of protection of this application.

[0054] In some embodiments, multiple imaging components 2 are configured with unified optical axes, also known as optical axis alignment, meaning that the optical axes at different positions of the lens are in the same direction. A calibration method to achieve a unified optical axis structure can be to use a fixing device to synchronously move the lens and sensor in the X and Y directions, applying the principle of optical path reversibility to adjust from the direction of light incidence, so that the images of each lens group completely overlap, completing the calibration, achieving optical axis unification, and a baseline close to zero. This reduces the difficulty of image algorithm registration and improves the quality of the final fused image.

[0055] In some embodiments, the image distance of each imaging component 2 is a fixed value, and the focal length of each lens 21 is a fixed value; the fixed values ​​of the focal lengths of the lenses 21 included in different imaging components 2 are different. Specifically, the structure that achieves different values ​​for the first depth of field and the second depth of field can be that the first imaging component 201 includes a first lens 211 with a focal length equal to the first lens focal length, and the second imaging component 202 includes a second lens 212 with a focal length equal to the second lens focal length. The fixed values ​​of the first lens focal length and the second lens focal length are different, which makes it easy to set the image distance and easy to assemble the imaging system. At the same time, it can achieve the fusion of telephoto and short-focal lengths to obtain a larger field of view.

[0056] In other embodiments, the image distance of each imaging component 2 is a fixed value, and the focal length of each lens 21 is a fixed value; the fixed focal lengths of the lenses 21 included in different imaging components 2 are the same, but the fixed image distances are different. Specifically, the structure that achieves different values ​​for the first depth of field and the second depth of field can be as follows: the first imaging component 201 includes a first lens 211 and a first photosensitive element 221, the distance from the optical center of the first lens 211 to the first photosensitive element 221 is the first image distance, and the focal length of the first lens 211 is the first lens focal length; the second imaging component 202 includes a second lens 212 and a second photosensitive element 222, the distance from the optical center of the second lens 212 to the second photosensitive element 222 is the second image distance, and the focal length of the second lens 212 is the second lens focal length; the fixed values ​​for the first lens focal length and the second lens focal length are the same, but the fixed values ​​for the first image distance and the second image distance are different. In this way, the same lens 21 can be used for different imaging components 2, resulting in lower material costs. At the same time, images with similar field of view can be fused, resulting in less resolution loss during the registration process and higher clarity in the fused image.

[0057] In some embodiments, the focal length of lens 21 can be a fixed value of 0.1mm to 300mm; optionally, the focal length of lens 21 can be a fixed value of 1mm to 150mm; more preferably, the focal length of lens 21 can be a fixed value of 1mm to 50mm; further preferably, the focal length of lens 21 can be a fixed value of 1mm to 20mm; even more preferably, the focal length of lens 21 can be a fixed value of 1mm to 16mm; and still more preferably, the focal length of lens 21 can be a fixed value of 1mm to 5mm.

[0058] In some embodiments, the focal length of lens 21 can be as shown in Figure 1, with two imaging components, the focal lengths of the first lens and the second lens being 1.94mm and 4mm respectively; or the focal lengths of the first lens and the second lens being 3mm and 200mm respectively; or the focal lengths of the first lens and the second lens being 135mm and 200mm respectively. Alternatively, it can be as shown in Figure 2, with three imaging components, the focal lengths of the first lens, the second lens, and the third lens 213 of the third imaging component 203 being 1.94mm, 4mm, and 16mm respectively; or the focal lengths of the first lens, the second lens, and the third lens being 3mm, 50mm, and 210mm respectively; or the focal lengths of the first lens, the second lens, and the third lens being 85mm, 135mm, and 300mm respectively. That is, the focal length of the lens 21 in each imaging component is different, and there is no limitation on the specific range of the focal length or the difference in focal length between different lenses.

[0059] Referring to Figures 1 and 2, in some embodiments, the imaging system 100 further includes a heat sink 4, which is fluidly connected to the beam splitter 1 and / or multiple imaging components 2, to prevent the imaging system 100 from overheating and further improve the imaging quality. The specific structure of the heat sink 4 can be a fan, a thermally conductive material component, or a water-cooled / air-cooled heat exchanger, heat pipe, or other common heat dissipation structures, and is not limited thereto.

[0060] This application also provides an imaging device having the imaging system 100 described in the above embodiments. The imaging device includes an indoor monitoring system and a stereo vision industrial camera. Specific examples of different imaging devices are described below.

[0061] Example 1

[0062] The imaging device is an indoor monitoring system, comprising an imaging system 100 as shown in Figure 1, including a beam splitter 1, two imaging components 2, namely a first imaging component 201 and a second imaging component 202, and an image processor 3. The beam splitter 1 is a 28×20×20mm cuboid prism, elongated along the light-incident and exit surfaces to ensure it does not obstruct the camera's field of view. The prism contains a standard 50:50 visible light coating in the middle, splitting the incident light beam 200 into two beams with directions corresponding to the X direction (same as the light beam 200) and the Y direction (perpendicular to the light beam 200), namely the first beam 2001 and the second beam 2002.

[0063] The first lens 211 has a focal length of 1.94mm, and the second lens 212 has a focal length of 4mm. Both the first and second image sensors 221 and 222 are CMOS sensors. The first imaging assembly 201 and the second imaging assembly 202 are configured as a first camera and a second camera, respectively, both being RGB cameras. The first imaging assembly 201 is located at the first beam 2001, and the second imaging assembly 202 is located at the second beam 2002. A corresponding light shield can be provided on the camera mounting surface to reduce the impact of prism reflections on image quality. The indoor monitoring system is equipped with a corresponding heat sink 4, for example, to conduct heat from the camera processing board to the metal base via a thermally conductive material. The image processor 3 performs fusion processing on the image data acquired by the first and second image sensors 221 and 222. A semi-reflective beam splitter unifies the optical axes of cameras with different focal lengths, greatly reducing the baseline length of the two cameras, improving registration accuracy, and ensuring the final image quality of the system.

[0064] Example 2

[0065] The imaging device is an industrial camera, and its imaging system 100, as shown in Figure 2, includes a first beam splitter 101, a second beam splitter 102, three imaging components 2, the first imaging component 201 having a first lens 211 and a first photosensitive element 221, the second imaging component 202 having a second lens 212 and a second photosensitive element 222, the third imaging component 203 having a third lens 213 and a third photosensitive element 223, and an image processor 3. The first beam splitter 101 and the second beam splitter 102 are both 28×20×20mm cuboid prisms, elongated along the light entry and exit surfaces. The prisms contain a standard 50:50 visible light coating in the middle, which can split the incident light beam into two beams. Beam splitter 1 splits the incident light beam into two beams, one in the same direction as the incident light and the other perpendicular to it. First beam splitter 101 splits beam 200 into a first beam 2001 and a second beam 2002. First beam 2001 is received by first imaging component 201, and second beam 2002 is received by second beam splitter 102, splitting into a third beam 2003 and a fourth beam 2004. Third beam 2003 is received by second imaging component 202, and fourth beam 2004 is received by third imaging component 203. The focal length of first lens 211 is configured to be 1.05mm, the focal length of second lens 212 is configured to be 4mm, and the focal length of third lens 213 is configured to be 12mm. First photosensitive element 221, second photosensitive element 222, and third photosensitive element 223 are all CMOS sensors. Image processor 3 acquires image data collected by the first photosensitive element 221, the second photosensitive element 222, and the third photosensitive element 223 respectively, namely, the first image corresponding to the first depth of field, the second image corresponding to the second depth of field, and the third image corresponding to the third depth of field. The first depth of field, the second depth of field, and the third depth of field are different, and fusion processing is performed.

[0066] Example 3

[0067] The imaging device is an industrial camera. Compared with Embodiment 2, the difference lies in that the first lens 211, the second lens 212, and the third lens 213 are the same, and the focal length of each lens is 4mm. However, the first image distance of the first imaging component 201, the second image distance of the second imaging component 202, and the third image distance of the third imaging component 203 are all different, thereby achieving different depths of field. The image processor 3 acquires the image data collected by the first photosensitive element 221, the second photosensitive element 222, and the third photosensitive element 223, respectively, which are the first image corresponding to the first depth of field, the second image corresponding to the second depth of field, and the third image corresponding to the third depth of field. The first depth of field, the second depth of field, and the third depth of field are different and are fused together.

[0068] As described above, this application also provides an imaging method using the imaging system 100 as described in the above embodiments, the imaging method comprising:

[0069] Multiple imaging components output multiple images corresponding to different depths of field to the image processor, which then fuses these images to output a fused image. Examples of multiple imaging components can be two, three, or even more, and are not limited to the number shown in Figures 1 and 2.

[0070] Optionally, the imaging method includes:

[0071] S101. Output the first image to the image processor through the first imaging component 201 corresponding to the first depth of field;

[0072] S102. Output a second image to the image processor via the second imaging component 202 corresponding to the second depth of field;

[0073] S200. The image processing device fuses the first image and the second image and outputs a fused image.

[0074] In summary, the imaging system and imaging device described in the above embodiments have the following beneficial effects, including but not limited to: by configuring the optical structure of the beam splitter-multiple imaging components-image processor optical path and electrical signal flow, images with different depths of field provided by different imaging components can be fused in the image processor. This achieves the advantages of using a fixed-focus camera, which has simple calibration and good robustness of calibration results, while overcoming the shortcomings of the limited depth of field range of fixed-focus cameras, which greatly limits the applicable scenarios.

[0075] While this application discloses preferred embodiments as described above, it is not intended to limit the scope of this application. Any changes and modifications can be made by those skilled in the art without departing from the spirit and scope of this application. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall fall within the protection scope defined by the claims of this application.

Claims

1. An imaging system (100), characterized by, The application relates to an optical imaging device, comprising: a beam splitter (1) capable of splitting a light beam input into the beam splitter (1) into a plurality of light beams output in different output directions; a plurality of imaging assemblies (2) corresponding to receiving the light beams in each output direction and outputting electrical signals, each imaging assembly (2) comprising: a lens (21) corresponding to receiving the light beams in each output direction; a photosensitive element (22) corresponding to receiving the light beams output by the lens (21) and converting the light beams into electrical signals, the output direction of the electrical signals output by the photosensitive element (22) being configured to point to an image processor (3); wherein the image distance of the imaging assembly (2) is defined as the distance from the optical center of the lens (21) to the photosensitive element (22), and the focal length of the lens is defined as the distance from the optical center of the lens to the focus point of the light gathering when parallel light is incident; for the plurality of imaging assemblies (2), at least a first imaging assembly (201) corresponding to a first depth of field and a second imaging assembly (202) corresponding to a second depth of field, the values of the first depth of field and the second depth of field being different; optionally, the image distance of each imaging assembly (2) is a fixed value, and the focal length of each lens (21) is a fixed value.

2. The imaging system (100) as claimed in claim 1, characterized in that the plurality of imaging assemblies (2) are configured to have uniform optical axes; the image distance of each imaging assembly (2) is a fixed value, and the focal length of each lens (21) is a fixed value; the fixed values of the focal lengths of the lenses (21) included in different imaging assemblies (2) are different; optionally, the first imaging assembly (201) comprises a first lens (211) having a first lens focal length, and the second imaging assembly (202) comprises a second lens (212) having a second lens focal length, the fixed values of the first lens focal length and the second lens focal length being different.

3. The imaging system (100) as claimed in claim 1, characterized in that the plurality of imaging assemblies (2) are configured to have uniform optical axes; the image distance of each imaging assembly (2) is a fixed value, and the focal length of each lens (21) is a fixed value; the values of the focal lengths of the lenses (21) included in different imaging assemblies (2) are the same, and the fixed values of the image distances are different; optionally, the first imaging assembly (201) comprises a first lens (211) and a first photosensitive element (221), the distance from the optical center of the first lens (211) to the first photosensitive element (221) is a first image distance, and the focal length of the first lens (211) is a first lens focal length; the second imaging assembly (202) comprises a second lens (212) and a second photosensitive element (222), the distance from the optical center of the second lens (212) to the second photosensitive element (222) is a second image distance, and the focal length of the second lens (212) is a second lens focal length; the fixed values of the first lens focal length and the second lens focal length are the same, and the fixed values of the first image distance and the second image distance are different.

4. The imaging system (100) as claimed in claim 1, characterized in that one or more of the beam splitters (1) are included. Optionally, the imaging system (100) comprises a plurality of beam splitters (1) arranged in sequence in the same direction, the number of the beam splitters (1) is N, the number of the plurality of imaging assemblies (2) corresponding to the arrangement is N+1, N is a positive integer greater than or equal to 2; Further optionally, the imaging system (100) comprises two beam splitters (1) corresponding to three imaging assemblies (2).

5. The imaging system (100) as claimed in claim 1, characterized in that The beam splitter (1) is a cuboid, and the long side of the cuboid corresponds to the connection between the light-in surface and the light-out surface of the beam splitter (1); or the beam splitter (1) is a cube.

6. The imaging system (100) as claimed in claim 1, characterized in that The beam splitter (1) has a beam splitting surface (11) with a semi-transmissive and semi-reflective film (110); Optionally, the semi-transmissive and semi-reflective film (110) is a visible light coating film with a beam splitting ratio of transmission:reflection = 50%:50%; Optionally, the reflected light output by the beam splitter (1) corresponds to a first optical axis (2011), and the transmitted light output by the beam splitter (1) corresponds to a second optical axis (2012), the first optical axis (2011) is perpendicular to the second optical axis (2012).

7. The imaging system (100) as claimed in claim 1, characterized in that The lens focal length of the lens (21) is a fixed value of 0.1mm to 300mm; Optionally, the lens focal length of the lens (21) is a fixed value of 1mm to 150mm; More optionally, the lens focal length of the lens (21) is a fixed value of 1mm to 50mm; Further optionally, the lens focal length of the lens (21) is a fixed value of 1mm to 20mm; Still further optionally, the lens focal length of the lens (21) is a fixed value of 1mm to 16mm; Yet further optionally, the lens focal length of the lens (21) is a fixed value of 1mm to 5mm.

8. The imaging system (100) as claimed in claim 1, characterized in that The photosensitive element (22) is a CCD element or a CMOS element; The imaging assembly (2) is configured as an integrated camera; Optionally, the integrated camera is an RGB camera; Optionally, the lens (21) of the integrated camera has a light shield.

9. The imaging system (100) as claimed in claim 1, characterized in that Further comprising a heat dissipation member (4) in fluid communication with the beam splitter (1) and / or the plurality of imaging assemblies (2).

10. An imaging device, characterized by The imaging system (100) has the imaging system (100) according to any one of claims 1-9, and the imaging device comprises an indoor monitoring system or a stereo vision industrial camera.

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