Single-camera optical image-splitting imaging system based on optical features

Abstract

This invention discloses a single-camera optical image separation imaging system based on optical features, comprising an incident light module, a beam splitting module, a reflection adjustment module, and an imaging module. The incident light module, consisting of a front-facing image system and a collimating lens group, collimates the light beam before it is incident on the beam splitting module. The beam splitting module separates the beam into four independent beams. A reflection adjustment module, located between the beam splitting module and the imaging module, adjusts the four beams into separate off-axis beams and reflects them to a broadband achromatic lens group. Finally, these beams are simultaneously imaged onto four different quadrants of the image sensor. The advantages are that the broadband achromatic lens group achieves near-diffraction-limited imaging performance, and the symmetrical structure design with the collimating lens group ensures uniform light intensity distribution across the entire field of view. While reducing cost and size, it is compatible with image separation imaging requirements based on multi-dimensional optical features such as wavelength, polarization state, and focal plane.

Description

Technical Field

[0001] This invention relates to an optical imaging system, and more particularly to a single-camera optical image separation imaging system based on optical features. Background Technology

[0002] Modern imaging systems place increasingly higher demands on the ability to simultaneously acquire multi-dimensional physical information. In the life sciences, wavelength-splitting multichannel fluorescence imaging is a fundamental supporting technology for research in cell biology and pharmacology. In materials and industrial inspection, polarization imaging can observe material stress distribution and perform non-destructive testing of defects in transparent parts, making it a key technology for high-end manufacturing. In three-dimensional dynamic imaging, simultaneous imaging technology with different focal planes can achieve volumetric imaging of thick samples and three-dimensional reconstruction of dynamic processes in living organisms, making it an important imaging technology in the life sciences. The core common requirement of all these application scenarios is to achieve image separation and simultaneous imaging based on optical characteristics such as different wavelengths, polarization states, or focal planes. However, current mainstream technical solutions lack an overall design concept for optical systems, consistently failing to simultaneously address requirements such as imaging synchronization, temporal resolution, spatial resolution, and system cost, thus hindering the development of related technologies' application scenarios.

[0003] The mainstream technical solutions in the industry can be divided into three categories according to the technical type and scenario: multi-camera parallel beam splitting imaging solution; single-camera time-series switching imaging solution; and single-camera multi-optical-path static beam splitting imaging solution.

[0004] Multi-camera parallel beam splitting imaging schemes require an additional camera and a matching optical path module for each additional channel, resulting in a large system size, poor scalability, and an inability to flexibly adapt to multi-channel imaging needs.

[0005] However, single-camera time-series switching imaging schemes have inherent time differences in images with different optical characteristics obtained by different shooting methods, which may lead to problems such as imaging artifacts and large co-positioning errors between channels. At the same time, mechanical switching components are used at high frequency for a long time, which can lead to problems such as decreased positioning accuracy and decreased light throughput of electronically controlled light transmission components, resulting in high system maintenance costs.

[0006] The single-camera multi-path static beam splitting imaging scheme is the latest optimized solution in the industry for single-camera multi-channel synchronous imaging. Its core principle is as follows: Incident light is separated into multiple independent optical paths according to optical characteristics (e.g., wavelength) using hierarchical beam-splitting elements (e.g., dichroic mirror groups). Each optical path is equipped with an independent focusing lens and a six-dimensional adjustable reflector group. By folding the optical paths, the image planes of multiple channels are arranged on different regions of a single large-scale camera, achieving multi-channel synchronous imaging without mechanical switching. For example, existing technologies use a third-order dichroic mirror to split the beam into four conjugate fluorescence channels. Each conjugate fluorescence channel is equipped with an independent axially adjustable focusing lens and reflector adjustment mechanism. Finally, a 2×2 reflector array is used to synchronously image the four channel image planes onto the target surface of a single camera. While this solution addresses the time difference issue of timing-switching schemes and the cost problem of multi-camera schemes, it still suffers from the following insurmountable core technical defects: Each conjugate fluorescence channel is equipped with an independent focusing lens and axial fine-tuning mechanism. Individual axial adjustment of the axially adjustable focusing lens for each conjugate fluorescence channel is required to correct chromatic aberration and calibrate focal plane conjugation, making adjustment difficult. Furthermore, each channel is equipped with multiple adjustment mechanisms such as a six-dimensional mirror adjustment frame and a linear translation stage, resulting in a large number of parts, significant cumulative assembly tolerances, and difficulty in ensuring imaging consistency across different devices during mass production. Long-term use can lead to a decrease in overall conjugation accuracy due to single-channel optical path drift, resulting in high maintenance costs. Additionally, even if the independent focusing lenses for each channel are manufactured in the same batch, machining tolerances such as focal length and surface shape are unavoidable. This can lead to inherent differences in the optical transfer function and point spread function of each channel, making it difficult to uniformly correct aberrations across channels and achieve uniform high-resolution imaging across the entire field of view. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a single-camera optical image separation imaging system based on optical features that is relatively simple in structure and easy to adjust and maintain.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a single-camera optical image separation imaging system based on optical characteristics, including an incident light module, a beam splitting module, and an imaging module. The incident light module consists of a front-view image system and a collimating lens group. The collimating lens group is used to collimate the light beam emitted by the front-view image system and then incident it onto the beam splitting module. The beam splitting module is used to split the light beam into four beams. A reflection adjustment module is provided between the beam splitting module and the imaging module. The imaging module consists of a single broadband achromatic lens group and a single image sensor. The reflection adjustment module receives the four beams emitted from the beam splitting module and adjusts the four beams into four mutually separated off-axis beams, reflecting them onto the broadband achromatic lens group. After passing through the broadband achromatic lens group, the four off-axis beams are respectively imaged in four different quadrants of the image sensor.

[0009] Compared to existing technologies, the advantages of this invention lie in its use of an overall optimized optical system and a single image sensor to form the imaging module. By setting a reflection adjustment module between the beam splitting module and the imaging module, the four beams reflected by the beam splitting module are adjusted into four off-axis beams and reflected to a broadband achromatic lens group. The broadband achromatic lens group then images the four off-axis beams onto four different quadrants of the image sensor. The broadband achromatic lens group in this invention is used for beam collimation and imaging, and is specifically designed and optimized for on-axis and off-axis beam imaging. It supports an NA ≥ 0.03 for the imaged beam, a maximum image plane size of 24 × 24 mm, and an absolute value of the incident beam angle greater than or equal to 4°. Full-field imaging maintains the diffraction limit, achieving high-resolution imaging. Through overall system optimization, very small imaging field curvature and distortion can be achieved. This solution addresses the core shortcomings of existing single-camera static beam splitting solutions, such as high installation and adjustment difficulty, poor imaging consistency, and limited field of view. It eliminates the need for multiple cameras, significantly reducing system hardware costs and size while achieving high-resolution imaging close to the diffraction limit across the entire field of view. It is compatible with image separation imaging requirements for multi-dimensional optical features and has high application value and promising prospects for promotion.

[0010] When an optical image separation imaging system splits the original image into four images, these images are formed as four independent and non-overlapping images in four different quadrants with a common origin. The system can achieve multi-image plane synchronous separation imaging based on optical characteristics using a single camera. It can separate the target image into multiple independent image planes in a single exposure according to optical characteristics such as wavelength, polarization state, and depth of focus, and simultaneously image them onto the photosensitive surface of a single image sensor. While ensuring high-speed snapshot imaging, it achieves high-resolution and high-uniformity imaging across the entire field of view, and is relatively easy to adjust and maintain.

[0011] In one feasible implementation, the beam splitting module may consist of a first beam splitting element, a second beam splitting element, a third beam splitting element, a first reflective element, a second reflective element, and a third reflective element. The first beam splitting element splits the light beam emitted from the collimating lens group into a transmitted beam and a reflected beam. The second beam splitting element splits the transmitted beam into a first beam splitting reflected to the reflection adjustment module and a second beam transmitted through it. The third reflective element reflects the second beam splitting to the reflection adjustment module. The first reflective element reflects the reflected beam to the third beam splitting element. The third beam splitting element splits the reflected beam into a third beam splitting reflected to the reflection adjustment module and a fourth beam transmitted through it. The second reflecting element is used to reflect the fourth beam to the reflection adjustment module. Each lens in the broadband achromatic lens group has a corresponding lens in the collimating lens group with the same structure, the same optical parameters, and opposite arrangement and orientation. This structure can maintain the Fourier transform relationship between the object and the image, ensure that the image plane and the object plane are almost the same size, and minimize imaging aberrations such as geometric distortion and astigmatism, thus maintaining good uniformity of light intensity distribution on the image plane. At the same time, the broadband achromatic lens group and the collimating lens group at the front end adopt a symmetrical structural design, which can maintain the Fourier transform relationship between the object and the image, ensure uniformity of light intensity distribution across the entire field of view, achieve unified correction of aberrations in all channels, and avoid the differences in imaging performance caused by multiple independent lenses.

[0012] In one feasible implementation, the reflection adjustment module comprises a first adjustable mirror, a second adjustable mirror, a third adjustable mirror, and a fourth adjustable mirror. The first adjustable mirror receives the first beam splitter and adjusts it to an off-axis beam, reflecting it onto the broadband achromatic lens group and imaging it in the first quadrant of the image sensor. The second adjustable mirror receives the third beam splitter and adjusts it to an off-axis beam, reflecting it onto the broadband achromatic lens group and imaging it in the second quadrant of the image sensor. The third adjustable mirror receives the fourth beam splitter and adjusts it to an off-axis beam, reflecting it onto the broadband achromatic lens group and imaging it in the third quadrant of the image sensor. The fourth adjustable mirror receives the second beam splitter and adjusts it to an off-axis beam, reflecting it onto the broadband achromatic lens group and imaging it in the fourth quadrant of the image sensor.

[0013] In one feasible implementation, to assist in the separation and imaging of characteristic beams, the single-camera optical image separation imaging system further includes four optical characteristic elements: a first optical characteristic element is disposed on the reflected light path of the second beam splitter, a second optical characteristic element is disposed on the transmitted light path of the second beam splitter, a third optical characteristic element is disposed on the reflected light path of the third beam splitter, and a fourth optical characteristic element is disposed on the transmitted light path of the third beam splitter.

[0014] In one feasible implementation, to assist in the separation and imaging of fluorescence at different wavelengths, the first beam-splitting element is a 580nm long-pass dichroic mirror, the second beam-splitting element is a 670nm long-pass dichroic mirror, the third beam-splitting element is a 480nm long-pass dichroic mirror, the first optical characteristic element is a fluorescence emission filter with a bandpass range of 570-610nm, the second optical characteristic element is a fluorescence emission filter with a bandpass range of 650-750nm, the third optical characteristic element is a fluorescence emission filter with a bandpass range of 420-470nm, and the fourth optical characteristic element is a fluorescence emission filter with a bandpass range of 500-550nm.

[0015] In one feasible implementation, in order to assist in the separation and imaging of beams with different polarization states, the first beam splitter can be a 580nm long-pass dichroic mirror, while the second and third beam splitters can be polarization beam splitters. The first and second optical characteristic elements are two polarizers with polarization states orthogonal to each other and having a first specific wavelength, and the third and fourth optical characteristic elements are two polarizers with polarization states orthogonal to each other and having a second specific wavelength, wherein the second specific wavelength is different from the first specific wavelength.

[0016] In one feasible implementation, in order to image a sample with a certain thickness, beams at different focal plane positions can be split simultaneously. The first, second, and third beam splitting elements can be 50 / 50 intensity beam splitters. The first optical feature element can be a positive lens with a focal length of 2000mm, the second optical feature element is a positive lens with a focal length of 4000mm, the third optical feature element is a positive lens with a focal length of 5000mm, and the fourth optical feature element is a positive lens with a focal length of 10000mm.

[0017] In one feasible implementation, the broadband achromatic lens group is composed of a first cemented doublet and a second cemented doublet sequentially along the beam propagation direction. The first cemented doublet is formed by cementing a first lens with positive optical power and a second lens with negative optical power. The refractive index of the first lens ranges from 1.41 to 1.44, and the refractive index of the second lens ranges from 1.56 to 1.60. The second cemented doublet is formed by cementing a third lens with positive optical power and a fourth lens with negative optical power. The refractive index of the third lens ranges from 1.68 to 1.72, and the refractive index of the fourth lens ranges from 1.56 to 1.59.

[0018] In one feasible implementation, the first cemented doublet has an object plane radius of curvature ranging from 200 mm to 210 mm, a cemented surface radius of curvature ranging from -40 mm to -60 mm, an image plane radius of curvature ranging from -170 mm to -190 mm, and a center thickness ranging from 7 mm to 10 mm; the second cemented doublet has an object plane radius of curvature ranging from 70 mm to 80 mm, a cemented surface radius of curvature ranging from -100 mm to -120 mm, an image plane radius of curvature ranging from 40 mm to 60 mm, and a center thickness ranging from 7 mm to 9 mm; the distance between the image plane of the first cemented doublet and the object plane of the second cemented doublet ranges from 18 mm to 20 mm; and the effective aperture of the first cemented doublet and the second cemented doublet is greater than or equal to 50 mm.

[0019] In one feasible implementation, a first reflection and refraction module is disposed between the front-facing image system and the collimating lens group; a second reflection and refraction module is disposed between the broadband achromatic lens group and the image sensor; and a dual reflection and refraction module is disposed between the reflection adjustment module and the broadband achromatic lens group. The first reflection and refraction module is used to reduce the physical distance between the front-facing image system and the collimating lens group; the second reflection and refraction module is used to reduce the distance between the broadband achromatic lens group and the image sensor; and the dual reflection and refraction module is used to reduce the distance between the four beam splitters. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the optical imaging system for wavelength separation provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the optical imaging system for splitting light polarization states provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of an optical imaging system for imaging at different depths provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the structure of the broadband achromatic lens group in the optical imaging system provided in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the imaging on the image sensor in the optical imaging system provided in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the optical imaging system provided in Embodiment 2 of the present invention; Figure 7 An optical transfer function curve of the field of view of an optical imaging system with an object height of Y=0mm, provided as a specific example of the present invention; Figure 8 An optical transfer function curve of the field of view of an optical imaging system with an object height Y=6mm provided as a specific example of the present invention; Figure 9 Field curvature diagram of an optical imaging system provided as a specific example of the present invention; Figure 10 Distortion diagram of an optical imaging system provided as a specific example of the present invention; Figure 11 A full field-of-view dot plot of an optical imaging system provided as a specific example of the present invention; Figure 12 This is an imaging result as a specific example of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Front-facing image system; 2. Fifth adjustable mirror; 3. Sixth adjustable mirror; 4. Collimating lens group; 5. First beam splitter; 6. First reflector; 7. Second beam splitter; 8. Third beam splitter; 9. Second optical feature element; 10. Fourth optical feature element; 11. First optical feature element; 12. Third optical feature element; 13. Second reflector; 14. Third reflector; 15. First adjustable mirror; 16. Second adjustable mirror; 17. Third adjustable mirror; 18. Fourth adjustable mirror; 19. Ninth adjustable mirror; 20. Tenth adjustable mirror; 21. Broadband image sensor Chromatic lens group; 211, first cemented doublet lens; 2111, first lens; 2112, second lens; 2121, third lens; 2122, fourth lens; 212, second cemented doublet lens; 22, seventh adjustable mirror; 23, eighth adjustable mirror; 24, image sensor; 24a, first quadrant of image sensor; 24b, second quadrant of image sensor; 24c, third quadrant of image sensor; 24d, fourth quadrant of image sensor; i1, transmitted beam; i2, reflected beam; ia, first beam splitter; id, second beam splitter; ib, third beam splitter; ic, fourth beam splitter. Detailed Implementation

[0022] The exemplary embodiments of the present invention are illustrated below with reference to the accompanying drawings. The drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention.

[0023] In the accompanying diagram, to illustrate the light path more clearly, the light path in the diagram may be slightly offset from the actual path, such as when it extends beyond the paper's surface.

[0024] Example 1: Figure 1 This invention illustrates a single-camera optical image separation imaging system based on optical features, comprising an incident light module, a beam splitting module, an imaging module, and a reflection adjustment module disposed between the beam splitting module and the imaging module. The incident light module consists of a front-facing image system 1 and a collimating lens group 4, and the imaging module consists of a single broadband achromatic lens group 21 and a single image sensor 24. Figure 4 As shown, the broadband achromatic lens group 21 consists of a first cemented doublet 211 and a second cemented doublet 212 along the beam propagation direction. The first cemented doublet 211 is cemented with low-dispersion crown glass and high-dispersion flint glass, and the second cemented doublet 212 is cemented with low-dispersion crown glass and high-dispersion flint glass. By matching the dispersion characteristics of multiple sets of optical glass, the axial chromatic aberration and transverse chromatic aberration in the wide spectral range of visible light from 400nm to 700nm are corrected. At the same time, special collaborative optimization is performed on coma, field curvature and distortion of off-axis image points to optimize the imaging quality of the edge field of view, and the imaging quality close to the diffraction limit can be achieved in the entire field of view. Preferably, the first cemented doublet lens 211 has an object plane radius of curvature ranging from 200mm to 210mm, a cemented surface radius of curvature ranging from -40mm to -60mm, an image plane radius of curvature ranging from -170mm to -190mm, and a center thickness ranging from 7mm to 10mm; the second cemented doublet lens 212 has an object plane radius of curvature ranging from 70mm to 80mm, a cemented surface radius of curvature ranging from -100mm to -120mm, an image plane radius of curvature ranging from 40mm to 60mm, and a center thickness ranging from 7mm to 9mm; the distance between the image plane of the first cemented doublet lens 211 and the object plane of the second cemented doublet lens 212 ranges from 18mm to 20mm; the effective aperture of the first cemented doublet lens 211 and the second cemented doublet lens 212 is greater than or equal to 50mm. Figure 4As shown, the first cemented doublet lens 211 is formed by cementing a first lens 2111 with positive optical power and a second lens 2112 with negative optical power. The refractive index of the first lens 2111 ranges from 1.41 to 1.44, and the refractive index of the second lens 2112 ranges from 1.56 to 1.60. The second cemented doublet lens 212 is formed by cementing a third lens 2121 with positive optical power and a fourth lens 2122 with negative optical power. The refractive index of the third lens 2121 ranges from 1.68 to 1.72, and the refractive index of the fourth lens 2122 ranges from 1.56 to 1.59. In order to maintain the Fourier transform relationship between the object and the image, ensure that the image plane and the object plane are almost the same size, minimize imaging aberrations such as geometric distortion and astigmatism, and maintain good uniformity of light intensity distribution on the image plane, each lens in the broadband achromatic lens group 21 has a corresponding lens in the collimating lens group 4 with the same structure, the same optical index, and the opposite arrangement order and orientation within the group. The beam splitting module consists of a first beam splitting element 5, a second beam splitting element 7, a third beam splitting element 8, a first reflecting element 6, a second reflecting element 13, and a third reflecting element 14. The reflection adjustment module consists of a first adjustable reflector 15, a second adjustable reflector 16, a third adjustable reflector 17, and a fourth adjustable reflector 18. The first beam splitting element 5 splits the beam emitted from the collimating lens group 4 into a transmitted beam i1 and a reflected beam i2. The second beam splitting element 7 splits the transmitted beam i1 into a reflected first beam ia and a transmitted second beam id. The first reflecting element 6 reflects the reflected beam i2 to the third beam splitting element 8. The third beam splitting element 8 splits the reflected beam i2 into a reflected third beam ib and a transmitted fourth beam ic. The first adjustable reflector 15 receives the first beam ia, the second adjustable reflector 16 receives the third beam ib, the third adjustable reflector 17 receives the fourth beam ic reflected by the second reflecting element 13, and the fourth adjustable reflector 18 receives the second beam id reflected by the third reflecting element 14. The first adjustable mirror 15 reflects and adjusts the first split beam ia into an off-axis beam, which is then imaged in the first quadrant 24a of the image sensor 24 after passing through the broadband achromatic lens group 21. The second adjustable mirror 16 reflects and adjusts the third split beam ib into an off-axis beam, which is then imaged in the second quadrant 24b of the image sensor 24 after passing through the broadband achromatic lens group 21. The third adjustable mirror 17 reflects and adjusts the fourth split beam ic into an off-axis beam, which is then imaged in the third quadrant 24c of the image sensor 24 after passing through the broadband achromatic lens group 21. The fourth adjustable mirror 18 reflects and adjusts the second split beam id into an off-axis beam, which is then imaged in the fourth quadrant 24d of the image sensor 24 after passing through the broadband achromatic lens group 21. Figure 5 Four images are shown, which are imaged in four different quadrants 24a, 24b, 24c, and 24d of the image sensor 24.

[0025] To further assist in the separation and imaging of characteristic beams, it is advisable to set a first optical characteristic element 11 in the reflected light path of the second beam splitter 7, a second optical characteristic element 9 in the transmitted light path of the second beam splitter 7, a third optical characteristic element 12 in the reflected light path of the third beam splitter 8, and a fourth optical characteristic element 10 in the transmitted light path of the third beam splitter 8.

[0026] In one embodiment, in order to split fluorescence of different wavelengths, the first beam splitter 5 can be a 580nm long-pass dichroic mirror, the second beam splitter 7 can be a 670nm long-pass dichroic mirror, the third beam splitter 8 can be a 480nm long-pass dichroic mirror, the first optical feature element 11 is a fluorescence emission filter with a bandpass range of 570-610nm, the second optical feature element 9 is a fluorescence emission filter with a bandpass range of 650-750nm, the third optical feature element 12 is a fluorescence emission filter with a bandpass range of 420-470nm, and the fourth optical feature element 10 is a fluorescence emission filter with a bandpass range of 500-550nm.

[0027] In one embodiment, it is possible to split light of different polarization states and wavelengths, such as... Figure 2 As shown. In order to split beams with different polarization states, the first beam splitter 5 can be a 580nm long-pass dichroic mirror, while the second beam splitter 7 and the third beam splitter 8 can be polarization beam splitting crystals. The first optical feature element 11 and the second optical feature element 9 are two polarizers with polarization states orthogonal to each other and having a first specific wavelength. The third optical feature element 12 and the fourth optical feature element 10 are two polarizers with polarization states orthogonal to each other and having a second specific wavelength. The second specific wavelength is different from the first specific wavelength.

[0028] In one embodiment, imaging of images at different depths can be achieved, such as... Figure 3As shown. When focusing and imaging images at different depths in the sample is required, beams at different focal plane positions can be split simultaneously. The first beam splitter 5, the second beam splitter 7, and the third beam splitter 8 can be 50 / 50 intensity beam splitters. The first optical feature element 11 can be a positive lens with a focal length of 2000mm, the second optical feature element 9 can be a positive lens with a focal length of 4000mm, the third optical feature element 12 can be a positive lens with a focal length of 5000mm, and the fourth optical feature element 10 can be a positive lens with a focal length of 10000mm. At this time, the front object plane of the system is slightly separated on the optical axis. At the four object planes (1-1, 1-2, 1-3, 1-4), the image plane of the system is in the same plane. The aforementioned four object planes correspond one-to-one with the four image planes (24a, 24b, 24c, 24d). Typically, the placement of each lens should ensure that the optical path from the collimating lens group 4 to each lens is the same. In this case, the depth of focus (relative to the image before the lenses are placed) can be changed without altering the image magnification. Additional lenses are generally a combination of converging and diverging lenses; however, if necessary, only converging or diverging lenses may be used.

[0029] Example 2: Figure 6 As shown, based on Embodiment 1, in order to reduce the physical distance between the front image system 1 and the collimating lens group 4, and to further adjust the incident angle to adapt to more different types of front image systems 1, a first reflection and refraction module composed of a fifth adjustable mirror 2 and a sixth adjustable mirror 3 can be set between the front image system 1 and the collimating lens group 4. Similarly, in order to reduce the distance between the broadband achromatic lens group 21 and the image sensor 24, a second reflection and refraction module composed of a seventh adjustable mirror 22 and an eighth adjustable mirror 23 can be set between the broadband achromatic lens group 21 and the image sensor 24. Furthermore, a double reflection and refraction module composed of a ninth adjustable mirror 19 and a tenth adjustable mirror 20 is set between the reflection adjustment module and the broadband achromatic lens group 21. This reduces the distance between the four beam splitters, thereby reducing the aperture of the broadband achromatic lens group 21, lowering costs, and reducing manufacturing difficulty. Figure 6 As can be seen, the first beam ia reflected by the first adjustable mirror 15 and the second beam id reflected by the fourth adjustable mirror 18 are deflected by the ninth adjustable mirror 19 and the tenth adjustable mirror 20 in sequence before entering the broadband achromatic lens group 21, while the third beam ib reflected by the second adjustable mirror 16 and the fourth beam ic reflected by the third adjustable mirror 17 directly enter the broadband achromatic lens group 21.

[0030] To further illustrate embodiments of the present invention, a specific example is provided below. In this example, the structure is as follows: Figure 6As shown. The front-end image system 1 uses a NIB1000 inverted fluorescence microscope from Yongxin Optics Co., Ltd. The first beam splitter 5, the second beam splitter 7, and the third beam splitter 8 are selected as 580nm, 670nm, and 480nm long-pass dichroic mirrors, respectively. To enhance the fluorescence filtering effect, the first optical feature element 11 is a 570-610nm bandpass fluorescence emission filter, the second optical feature element 9 is a 650-750nm bandpass fluorescence emission filter, the third optical feature element 12 is a 420-470nm bandpass fluorescence emission filter, and the fourth optical feature element 10 is a 500-550nm bandpass fluorescence emission filter, further filtering out the target fluorescence. The image sensor 24 is an area array detector. In this example, a visible light area array detector with a pixel size of 6.5µm and a resolution of 3200×3200 pixels is selected. The imaging performance of the system was evaluated. The maximum effective field of view of the front imaging system 1 is 12×12mm, and the maximum effective image plane of the image sensor 24 is 24×24mm. Its optical transfer function is as follows: Figure 7 , Figure 8 As shown, the horizontal axis represents spatial frequency, with units of period / mm (lp / mm, line pairs per millimeter), used to describe the fineness of image details; the vertical axis represents the OTF modulus, representing the contrast reproduction capability of the optical system for targets of different spatial frequencies, with a value range of 0 to 1, where 1 indicates the best reproduction and 0 indicates the worst reproduction. Figure 7 The optical transfer function of the light rays and the diffraction limit of the system are shown at a field of view with an object height of Y=0mm; Figure 8 In the diagram, the red line represents the optical transfer function of light rays in the field of view at an object height of Y=6mm and the diffraction limit of the system. Figure 9 The field curvature of this example is shown. The curves in the figure correspond to the imaging field curvature of light with wavelengths of 455nm, 587nm, and 656nm, respectively. The absolute value of the maximum field curvature is <0.2mm. Y in the vertical axis (+Y) represents the object height. Figure 10 The distortion in this example is shown. The curves in the figure correspond to light wavelengths of 455nm, 587nm, and 656nm, respectively. The absolute value of the maximum distortion across the entire field of view of the system is <0.05%. Y in the vertical axis (+Y) represents the object height. Figure 11 The full field-of-view dot plot of this example system is shown. The four images represent the imaging dot plots corresponding to different object and image plane positions. The outer circle indicates the diffraction limit of the system, and the dots inside the circle represent light wavelengths of 455 nm, 587 nm, and 656 nm, respectively. Among them, the image marked (a) represents the object plane position X. 物 =0.0, Y 物 The image point array with a diameter of 0.0 mm corresponds to the image plane position X. 像 =5.201, Y 像=5.201mm; the image marked (b) indicates the object's position as X. 物 =0.0, Y 物 The image point array with a diameter of 6.0 mm corresponds to the image plane position X. 像 =5.1991, Y 像 = -0.804mm; the image marked (c) indicates the object's position as X. 物 =6.0, Y 物 The image point array with a diameter of 0.0 mm corresponds to the image plane position X. 像 =-0.804, Y 像 = -5.196mm; the image marked (d) indicates the object's position as X. 物 =6.0, Y 物 The image point array with a diameter of 6.0 mm corresponds to the image plane position X. 像 =-0.802, Y 像 =-0.805mm. In the full field of view, the point array of light rays on the image plane is almost entirely within the diffraction limit. Figure 12 This example demonstrates imaging using a 60x objective lens. Fluorescence imaging was performed on four samples from the U-2OS cell line: microfilaments, microtubules, mitochondria, and nuclei. The system separates the fluorescence images at the microscope image plane based on wavelength, arranging them independently in the four quadrants of the image plane.

[0031] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the scope of the claims of the present invention shall fall within the protection scope of the present invention.

Claims

1. A single-camera optical image separation imaging system based on optical features, comprising an incident light module, a beam splitting module, and an imaging module, wherein the incident light module consists of a front-facing image system and a collimating lens group, the collimating lens group being used to collimate the light beam emitted by the front-facing image system before it is incident on the beam splitting module, and the beam splitting module being used to split the light beam into four beams, characterized in that, A reflection adjustment module is provided between the beam splitting module and the imaging module. The imaging module consists of a single broadband achromatic lens group and a single image sensor. The reflection adjustment module receives the four beams emitted from the beam splitting module and adjusts the four beams into four separate off-axis beams, which are then reflected onto the broadband achromatic lens group. After passing through the broadband achromatic lens group, the four off-axis beams are respectively imaged in four different quadrants of the image sensor.

2. The single-camera optical image separation imaging system based on optical features according to claim 1, characterized in that, The beam splitting module comprises a first beam splitting element, a second beam splitting element, a third beam splitting element, a first reflective element, a second reflective element, and a third reflective element. The first beam splitting element splits the beam emitted from the collimating lens group into a transmitted beam and a reflected beam. The second beam splitting element splits the transmitted beam into a first beam reflected to the reflection adjustment module and a second beam transmitted. The third reflective element reflects the second beam to the reflection adjustment module. The first reflective element reflects the reflected beam to the third beam splitting element. The third beam splitting element splits the reflected beam into a third beam reflected to the reflection adjustment module and a fourth beam transmitted. The second reflective element reflects the fourth beam to the reflection adjustment module. Each lens in the broadband achromatic lens group has a corresponding lens in the collimating lens group with the same structure, the same optical properties, and opposite arrangement and orientation within the group.

3. The single-camera optical image separation imaging system based on optical features according to claim 2, characterized in that, The reflection adjustment module comprises a first adjustable reflector, a second adjustable reflector, a third adjustable reflector, and a fourth adjustable reflector. The first adjustable reflector receives the first beam splitter, adjusts it to an off-axis beam, reflects it onto the broadband achromatic lens group, and images it in the first quadrant of the image sensor. The second adjustable reflector receives the third beam splitter, adjusts it to an off-axis beam, reflects it onto the broadband achromatic lens group, and images it in the second quadrant of the image sensor. The third adjustable reflector receives the fourth beam splitter, adjusts it to an off-axis beam, reflects it onto the broadband achromatic lens group, and images it in the third quadrant of the image sensor. The fourth adjustable reflector receives the second beam splitter, adjusts it to an off-axis beam, reflects it onto the broadband achromatic lens group, and images it in the fourth quadrant of the image sensor.

4. The single-camera optical image separation imaging system based on optical features according to claim 3, characterized in that, The single-camera optical image separation imaging system further includes four optical feature elements for assisting feature light separation imaging. The first optical feature element is disposed on the reflected light path of the second beam splitter, the second optical feature element is disposed on the transmitted light path of the second beam splitter, the third optical feature element is disposed on the reflected light path of the third beam splitter, and the fourth optical feature element is disposed on the transmitted light path of the third beam splitter.

5. A single-camera optical image separation imaging system based on optical features according to claim 4, characterized in that, The first beam splitter is a 580nm long-pass dichroic mirror, the second beam splitter is a 670nm long-pass dichroic mirror, the third beam splitter is a 480nm long-pass dichroic mirror, the first optical characteristic element is a fluorescent emission filter with a bandpass range of 570-610nm, the second optical characteristic element is a fluorescent emission filter with a bandpass range of 650-750nm, the third optical characteristic element is a fluorescent emission filter with a bandpass range of 420-470nm, and the fourth optical characteristic element is a fluorescent emission filter with a bandpass range of 500-550nm.

6. The single-camera optical image separation imaging system based on optical features according to claim 4, characterized in that, The first beam splitter is a 580nm long-pass dichroic mirror, the second and third beam splitters are polarization beam splitters, the first and second optical characteristic elements are two polarizers with polarization states orthogonal to each other and having a first specific wavelength, and the third and fourth optical characteristic elements are two polarizers with polarization states orthogonal to each other and having a second specific wavelength, wherein the second specific wavelength is different from the first specific wavelength.

7. A single-camera optical image separation imaging system based on optical features according to claim 4, characterized in that, The first, second, and third beam splitters are 50 / 50 intensity beam splitters. The first optical feature element is a positive lens with a focal length of 2000mm, the second optical feature element is a positive lens with a focal length of 4000mm, the third optical feature element is a positive lens with a focal length of 5000mm, and the fourth optical feature element is a positive lens with a focal length of 10000mm.

8. A single-camera optical image separation imaging system based on optical features according to claim 1, characterized in that, The broadband achromatic lens group is composed of a first cemented doublet and a second cemented doublet sequentially along the beam propagation direction. The first cemented doublet is formed by cementing a first lens with positive optical power and a second lens with negative optical power. The refractive index of the first lens ranges from 1.41 to 1.44, and the refractive index of the second lens ranges from 1.56 to 1.

60. The second cemented doublet is formed by cementing a third lens with positive optical power and a fourth lens with negative optical power. The refractive index of the third lens ranges from 1.68 to 1.72, and the refractive index of the fourth lens ranges from 1.56 to 1.

59.

9. A single-camera optical image separation imaging system based on optical features according to claim 8, characterized in that, The first cemented doublet has an object plane radius of curvature ranging from 200mm to 210mm, a cemented surface radius of curvature ranging from -40mm to -60mm, an image plane radius of curvature ranging from -170mm to -190mm, and a center thickness ranging from 7mm to 10mm; the second cemented doublet has an object plane radius of curvature ranging from 70mm to 80mm, a cemented surface radius of curvature ranging from -100mm to -120mm, an image plane radius of curvature ranging from 40mm to 60mm, and a center thickness ranging from 7mm to 9mm; the distance between the image plane of the first cemented doublet and the object plane of the second cemented doublet ranges from 18mm to 20mm; the effective aperture of both the first and second cemented doublets is greater than or equal to 50mm.

10. A single-camera optical image separation imaging system based on optical features according to claim 1, characterized in that, A first reflection and refraction module is provided between the front-facing image system and the collimating lens group; a second reflection and refraction module is provided between the broadband achromatic lens group and the image sensor; and a dual reflection and refraction module is provided between the reflection adjustment module and the broadband achromatic lens group. The first reflection and refraction module is used to reduce the physical distance between the front-facing image system and the collimating lens group; the second reflection and refraction module is used to reduce the distance between the broadband achromatic lens group and the image sensor; and the dual reflection and refraction module is used to reduce the distance between the four beam splitters.

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