Focusing module and automatic focusing microscopic imaging system
By using optical path difference elements in the autofocus system to divide the total focus beam into multiple focus beams, the problem of insufficient accuracy and anti-interference ability of the existing autofocus system is solved, and higher focus accuracy and more compactness are achieved system structure.
Patent Information
- Application Number
- CN202420439821.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-06
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-03-06
AI Technical Summary
The existing autofocus system has insufficient accuracy and anti-interference ability, and the related components are large in size and occupy a lot of space.
The total focusing beam is divided into at least three focusing beams with fixed optical path difference. These beams are received separately through the focus sensor group to improve the focus accuracy, and the system structure is compact through the design of the optical path difference element. Takes up small space.
The accuracy of autofocus and the anti-interference ability of the system are improved. At the same time, due to the compact structure of the optical path difference element, the system volume is reduced and the space occupies less.
Smart Images
Figure CN222506652U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of automatic focusing, in particular to a focusing module and an automatic focusing microscopic imaging system. Background Art
[0002] Existing optical systems such as microscopes and laser welding need to be focused before use. Existing optical systems can be focused manually or automatically. Manual focusing has low accuracy and is cumbersome, so optical systems are usually equipped with autofocus systems.
[0003] Existing autofocus systems usually collect a series of images near the focal point, analyze each frame, and achieve autofocus through changes in image clarity. However, the focusing accuracy of this method is low, the system has low anti-interference ability, and the autofocus-related components in existing systems are large and occupy a lot of space. Utility Model Content
[0004] Based on this, the purpose of the utility model is to provide a focusing module and an automatic focusing microscopic imaging system, which have the advantages of high focusing accuracy, compact structure, and small space occupation.
[0005] A focusing module, comprising
[0006] An optical path difference element, wherein the optical path difference element receives and processes the total focused light beam to obtain at least three focused light beams with optical path differences;
[0007] The focus sensor group is used to receive the focus light beams respectively.
[0008] The focusing module described in the utility model divides the focusing beam into at least three focusing beams with fixed optical path differences, thereby increasing the data that can be used by the prediction function and improving the focusing accuracy. Moreover, the focusing module only needs one optical path difference element and has a compact structure.
[0009] Furthermore, it also includes a plurality of focusing lenses, and the optical path difference element is a triangular prism; the triangular prism has an incident surface, a first exit surface and a second exit surface; the total focusing beam enters the triangular prism from the incident surface, and the triangular prism receives and processes the total focusing beam to obtain a first focusing beam, a second focusing beam and a third focusing beam; the first focusing beam, the second focusing beam and the third focusing beam are respectively projected into the focusing sensor group through the focusing lenses.
[0010] Furthermore, the first exit surface is coated with a semi-reflective and semi-transparent film, and the focusing lens includes a third focusing lens and a fourth focusing lens; the total focusing light beam enters the triangular prism from the incident surface, and part of it is emitted to the first exit surface, and is reflected to generate a first split light beam; part of it is emitted to the second exit surface, and is reflected to generate a second split light beam; the first split light beam passes through the second exit surface to form the second focusing light beam; part of the second split light beam passes through the first exit surface to form the first focusing light beam, and part of it is reflected, returns to and passes through the second exit surface to form the third focusing light beam; the first focusing light beam passes through the third focusing lens and is projected into the focusing sensor group, and the second and third focusing light beams pass through the fourth focusing lens and are respectively projected into the focusing sensor group.
[0011] Furthermore, the first exit surface and the second exit surface are coated with a semi-reflective and semi-transparent film, and the focusing module includes a third focusing lens, a fourth focusing lens and a fifth focusing lens; the total focusing light beam enters the triangular prism from the incident surface, and part of it is emitted to the first exit surface, and is reflected to generate a first split light beam; part of it is emitted to the second exit surface, and is reflected to generate a second split light beam; the second split light beam passes through the first exit surface to form the first focusing light beam; the first split light beam is irradiated on the second exit surface, and part of it passes through the second exit surface to form the second focusing light beam; part of it is reflected, returns to and passes through the first exit surface to form the third focusing light beam; the first focusing light beam, the second focusing light beam and the third focusing light beam are respectively projected into the focusing sensor group after passing through the third focusing lens, the fourth focusing lens and the fifth focusing lens respectively.
[0012] An automatic focusing microscopic imaging system, comprising:
[0013] A light source module, used for emitting a first light beam, wherein the first light beam is irradiated onto a sample to be tested to form an object light beam;
[0014] an objective lens, used for shaping the first light beam and the object beam;
[0015] A beam splitter element, used for splitting the object beam to obtain a total focus beam and an imaging beam;
[0016] An imaging module, used for receiving the imaging light beam and performing imaging;
[0017] The focus module mentioned above.
[0018] An automatic focusing microscopic imaging system, comprising:
[0019] A light source module, used for emitting a first light beam, wherein the first light beam is irradiated onto a sample to be tested to form an object light beam;
[0020] an objective lens, used for shaping the first light beam and the object beam;
[0021] A beam splitter element, used for splitting the object beam to obtain a total focus beam and an imaging beam;
[0022] An imaging module, used for receiving the imaging light beam and performing imaging;
[0023] In the aforementioned focusing module, the incident surface of the triangular prism is coated with a semi-reflective and semi-transparent film, and the automatic focusing microscopic imaging system also includes a review module; the review module includes a review sensor and a review lens; when the total focusing beam is incident from the incident surface, part of the light is incident on the triangular prism, and the other part of the light is reflected and incident on the review sensor through the review lens to form an image.
[0024] In order to better understand and implement the present invention, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is a schematic diagram of the optical path structure of the auto-focus microscopic imaging system of the utility model;
[0026] Figure 2 This is a schematic diagram of the optical path structure of the focus module of Example 1 of the utility model;
[0027] Figure 3 This is a schematic diagram of the optical path structure of the focus module of Example 2 of the utility model;
[0028] Figure 4 This is a schematic diagram of the optical path structure of the first emitting surface of the triangular prism of the focusing module of Example 3 of the utility model coated with a semi-reflective and semi-transparent film;
[0029] Figure 5 This is a schematic diagram of the optical path structure of the first emission surface, the second emission surface and the incident surface of the triangular prism of the focusing module of Example 3 of the utility model, which are coated with a semi-reflective and semi-transparent film;
[0030] Figure 6 This is a schematic diagram of the optical path structure of the focusing module of Example 3 of the utility model, in which the incident surface of the triangular prism is coated with a semi-reflective and semi-transparent film;
[0031] Figure 7 This is a schematic diagram of the optical path structure of the focus module of Example 4 of the utility model;
[0032] Figure 8 This is a light path structure diagram of a focusing module of Example 4 of the utility model, in which the incident surface of the hexagonal prism is coated with a semi-reflective and semi-transparent film;
[0033] Fig. 9 The present invention is a flowchart of an automatic focusing microscopic imaging method according to an embodiment of the present invention. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0035] In the description of the present invention, it should be noted that the terms "vertical direction", "upper", "lower", "horizontal" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0036] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a heat-conducting connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or a connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0037] Example 1
[0038] See also Figure 1 to Figure 2 The utility model provides an automatic focusing microscopic imaging system. The automatic focusing microscopic imaging system of the utility model comprises a light source module 1, a first beam splitter element 2, a second beam splitter element 3, an objective lens 4, a focusing module 5 and an imaging module 6. When working, the light source module 1 emits a first light beam, which is irradiated on the first beam splitter element 2 and then reflected on the objective lens 4; the first light beam passes through the objective lens 4 and then irradiates on the sample to be tested 7. The first light beam is reflected on the sample to be tested 7 to obtain an object light beam, which is then reflected back to the first beam splitter element 2 through the objective lens 4; then, it passes through the first beam splitter element 2 and enters the second beam splitter element 3, which splits the object light beam to obtain a total focusing light beam and an imaging light beam. The total focusing light beam is emitted into the focusing module 5, and after detection and calculation, it is determined whether the sample to be tested 7 is at the optimal focal position of the objective lens 4. The imaging light beam is emitted into the imaging module 6 for imaging.
[0039] The light source module 1 includes a first light source 11 and a light source shaping lens 12. The light emitted by the first light source 11 is shaped by the light source shaping lens 12 to form a first light beam. In this embodiment, the first light source 11 is a white light source, so the first light beam is mixed white light. In some embodiments, the white light source is used as both an illumination light source and a focusing light source.
[0040] Furthermore, the first beam splitting element 2 and the second beam splitting element 3 are beam splitting prisms.
[0041] Furthermore, the imaging module 6 includes an imaging sensor 61 and an imaging lens 62. The imaging light beam is shaped by the imaging lens 62 and then incident on the imaging sensor 61 to form an image on the imaging sensor 61.
[0042] Furthermore, the auto-focus microscopic imaging system also includes a control system and a driving module. The driving module is connected to the objective lens 4 or the sample stage, and is used to adjust the relative position between the objective lens 4 and the sample. The control system is electrically connected to the driving module, the focusing module 5 and the imaging module 6, and is used to receive and process the data collected by the focusing module 5 and the imaging module 6, and control the driving module to focus.
[0043] In some embodiments, the focus module 5 includes an optical path difference element, a first focus lens 511, and a focus sensor group. The optical path difference element is an X-ray light-combining prism 501, and the total focus beam is incident on the first focus lens 511. After being shaped by the first focus lens 511, it is incident on the X-ray light-combining prism 501 from the incident surface of the X-ray light-combining prism 501. The X-ray light-combining prism 501 has three exit surfaces; one of the exit surfaces is directly opposite to the incident surface, and the other two exit surfaces are directly opposite to each other and perpendicular to the incident surface.
[0044] After the total focus beam is processed by the X-light-combining prism 501, the first focus beam, the second focus beam and the third focus beam are emitted from the three exit surfaces of the X-light-combining prism 501 respectively; the focus sensor group includes three focus sensors 52, and the sensors can be CCD sensors or CMOS sensors. In some embodiments, the sensors are CMOS sensors; the X-light-combining prism 501 projects the first focus beam, the second focus beam and the third focus beam into the focus sensors 52 respectively.
[0045] After the total focus beam is processed by the X-ray light-combining prism 501, the first focus beam, the second focus beam, and the third focus beam are separated and have different wavelengths and colors. Since the three beams have different wavelengths, the refractive indexes of the first focus beam, the second focus beam, and the third focus beam in the same medium are different. Therefore, when the distances between the three focus sensors 52 and the X-ray light-combining prism 501 are equal, the optical paths of the first focus beam, the second focus beam, and the third focus beam reaching the focus sensor 52 are also different, and there is a fixed optical path difference between the three in the optical path, and three focus images with different depths of field are formed on the three focus sensors 52.
[0046] Based on multiple depth of field imaging effects, non-parametric statistical evaluation of image quality is implemented based on pixel information in each of the three focused images, and the evaluation criteria include but are not limited to Brenner operator, SMD operator, etc. When the objective lens 4 or the object under test moves for focus adjustment, the three focused images are statistically settled by the above method respectively, and finally the quality statistical scoring curves of the three focused images are output. The intervals where the highest values of the quality statistical scoring curves of the three focused images appear correspond to the focal plane difference formed by the inherent optical path difference formed by the optical path difference element in the optical path in the object imaging space.
[0047] The automatic focusing microscopic imaging system of the utility model needs to collect a set of quality statistical scoring curves in the field of view before use; based on the curve representation, the prediction function between the statistical scoring and the positive focus amount adjustment is constructed using the respective curves in the field of view of the three focus sensors 52, and the construction of the predicted adjustment amount includes but is not limited to the direct mapping method, the servo PID method and other methods. Through three-point sampling, the prediction of the focal depth position can be achieved more stably, and the clear imaging of the system can be achieved.
[0048] The automatic focusing microscopic imaging system of the utility model collects quality statistical scoring data through the field of view of at least three focusing sensors 52, and infers the specific focus of the objective lens 4, which effectively improves the accuracy of automatic focusing. In addition, the optical path difference element only needs to split light through one element, which is conducive to compressing space and reducing the volume of the automatic focusing microscopic imaging system.
[0049] See also Fig. 9 The present invention also provides an automatic focusing microscopic imaging method. The automatic focusing microscopic imaging method includes the following steps:
[0050] S1 simultaneously collects at least three focused images with optical path differences;
[0051] S2 thresholds and binarizes each focused image to obtain a binarized image D(x, y);
[0052] S3 extracts the centroid of each binary image D(x,y) and obtains the centroid position of each Determine the offset direction based on the positive and negative defocus outputs of the centroid position;
[0053] S4 performs statistics on the area of the connected domain based on the binary image D(x,y) to calculate the focus amount; multiple focus amounts are calculated and output as a final focus amount through an average mechanism;
[0054] The S5 focuses based on positive and negative defocus and the final focus amount.
[0055] Further, in step S1, the focusing image is the focusing image collected by the focusing sensor of the focusing module in the aforementioned automatic focus microscopic imaging system. Due to the presence of the optical path difference element, the optical path difference between the three focused images with optical path difference collected is fixed. Further, in the focusing process, when one of the focusing sensors whose optical path is neither the largest nor the smallest is imaged as approximately positive focus, its image is a narrow-band line excitation pattern. Taking the focusing module of this embodiment as an example, when the second focusing beam is imaged as approximately positive focus, the first focusing beam is imaged as positive defocus, and the third focusing beam is imaged as negative defocus. In some embodiments, the focusing image includes but is not limited to rectangular, cross-shaped, and other laser spots projected and imaged on each focusing module in a center-pull manner.
[0056] Furthermore, in step S2, the threshold segmentation and binarization method is as follows:
[0057]
[0058] Among them, I(x,y) is the original image, (x,y) is the pixel coordinate position, I max is the maximum value of the pixel grayscale in the original image, D(x,y) is the image after binarization, and D(x,y) depends on the dynamic threshold Realize the judgment of binary image, where k is usually 2, that is, half of the maximum grayscale value of the current frame is used as the threshold, and finally the binary image D(x,y) is output.
[0059] Furthermore, in step S3, the method of extracting the centroid is as follows:
[0060]
[0061] In some embodiments, when the centroid x0 is at the positive focus position, the projection surface of the positive focus image plane presents a standard rectangular light spot, wherein the left light spot image is a projection within the positive depth of field range, and the right light spot image is a projection within the negative depth of field range. At this time, the center offset is
[0062] when When , the positive focus image plane is negatively offset (focusing upward is positive), when When , the in-focus image plane is positively offset.
[0063] Due to the effect of the optical path difference prism, regardless of the defocus condition of the focal plane position, the centroid offset of the image plane collected by each focus sensor field of view is The numerical relationship between them remains unchanged, and due to the simultaneous imaging of multiple depths of field, the determination of the defocus offset direction is more accurate, avoiding the problem of mechanism focusing oscillation caused by the defocus direction error caused by the single depth of field spot imaging calculation error.
[0064] Furthermore, in step S4, the method for calculating the focus amount is to convert the width d of the focus image in the x direction into the focus amount. The specific method is as follows: the width d in the x direction is completed by fitting the straight lines on both sides of the y direction, and then the width values d0, d -1 ,d -2 ,d1,d2. The width d in the x direction and the focusing amount are converted into a nonlinear one-to-one mapping through the sequential imaging pre-calibration of the positive focus image plane; the sequential imaging pre-calibration results of the positive focus image plane can be used together by multiple focus sensor fields of view, and the calibration result lookup table LUT is completed to replace complex data calculations and improve efficiency.
[0065] Furthermore, in step S4, the average mechanism calculation includes but is not limited to weighted average and cluster average. In some embodiments, multi-point sampling of the focus curve can be implemented for the ideal spot image, and the "interpolation mechanism" output of the final focus amount can be implemented by a curve fitting method including but not limited to least squares curve fitting and cubic spline interpolation; at the same time, the final focus amount can also be output by the combination of the "average mechanism" and the "interpolation mechanism".
[0066] Compared with the prior art, the automatic focusing microscopic imaging method of the embodiment of the utility model, due to the participation of the optical path difference element, causes the laser spot collected by the focus sensor to present multi-focal position simultaneous imaging, thereby forming the simultaneous collection of focal position imaging information; each focus sensor independently determines the defocus amount and defocus direction through the morphological shape of the laser spot, and realizes the final focusing decision output process through joint processing. Due to the participation of multi-focal position simultaneous imaging, the determination of the defocus direction is more accurate and the determination of the defocus amount is clearer.
[0067] Example 2
[0068] See also Figure 3 This embodiment provides an auto-focus microscopic imaging system. The auto-focus microscopic imaging system in this embodiment is substantially the same as the auto-focus microscopic imaging system in Embodiment 1, except that the focus module 5 includes an optical path difference element, three second focus lenses 512 and a focus sensor group; the optical path difference element in this embodiment is a trapezoidal prism 502.
[0069] The trapezoidal prism 502 performs a light splitting process on the total focused beam, thereby obtaining a first focused beam, a second focused beam, and a third focused beam. The total focused beam enters the trapezoidal prism 502 from the bottom surface of the trapezoidal prism 502, and part of the light is emitted from the top surface of the trapezoidal prism 502 to form a first focused beam; part of the light is refracted on both side surfaces of the trapezoidal prism 502 to form a second focused beam and a third focused beam, which are emitted from both side surfaces of the trapezoidal prism 502 respectively.
[0070] The focus sensor group includes three focus sensors 52 ; the first focus beam, the second focus beam and the third focus beam are respectively projected into the focus sensor 52 after passing through the second focus lens 512 .
[0071] Since the optical paths of the first focus beam, the second focus beam and the third focus beam to the focus sensor 52 are different, there is a fixed optical path difference among the three in the optical path, and three focus images with different depths of field are formed on the three focus sensors 52 .
[0072] Furthermore, each surface of the trapezoidal prism is coated with an anti-reflection film, and the anti-reflection film is used to reduce stray light and improve the accuracy of auto-focusing.
[0073] Example 3
[0074] See also Figure 4-Figure 6 , this embodiment provides an auto-focus microscopic imaging system. The auto-focus microscopic imaging system in this embodiment is substantially the same as the auto-focus microscopic imaging system in Embodiment 1, except that: the focus module 5 includes an optical path difference element, a third focus lens 513, a fourth focus lens 514 and a focus sensor group; the optical path difference element in this embodiment is a triangular prism 503.
[0075] Further, the triangular prism 503 is an isosceles triangular prism 503. One side surface of the triangular prism 503 is an incident surface, the other side surface is a first emitting surface, and the bottom surface is a second emitting surface.
[0076] The focused main beam and the total focused beam are incident on the triangular prism 503 from the incident surface, and the triangular prism 503 performs a beam splitting process on the total focused beam.
[0077] See also Figure 4In some embodiments, the first exit surface of the triangular prism 503 is coated with a semi-reflective and semi-transparent film; the total focused light beam enters the triangular prism 503 from the incident surface parallel to the bottom surface, and part of it is emitted to the first exit surface, and is reflected on the first exit surface to generate a first split light beam; part of it is emitted to the second exit surface, and is reflected on the second exit surface to generate a second split light beam. The first split light beam passes through the second exit surface to form a second focused light beam; the second split light beam is irradiated on the first exit surface, and part of it passes through the first exit surface to form the first focused light beam, and part of it is reflected, returns to and passes through the second exit surface to form a third focused light beam.
[0078] The focus sensor group includes three focus sensors 52 ; the first focus beam is projected onto one of the focus sensors 52 after passing through the third focus lens 513 , and the second focus beam and the third focus beam are projected onto the other two focus sensors 52 after passing through the fourth focus lens 514 .
[0079] See also Figure 5 In other embodiments, the first and second exit surfaces of the triangular prism 503 are coated with a semi-reflective and semi-transparent film, and the focusing module 5 further includes a fifth focusing lens 515; the total focusing beam is incident on the triangular prism 503 from the incident surface in parallel with the bottom surface, part of which is incident on the first exit surface, and is reflected on the first exit surface to generate a first split beam; part of which is incident on the second exit surface, and is reflected on the second exit surface to generate a second split beam. The second split beam passes through the first exit surface to form a first focusing beam. The first split beam is irradiated on the second exit surface, part of which passes through the second exit surface to form a second focusing beam; part of which is reflected on the second exit surface, returns to and passes through the first exit surface to form a third focusing beam.
[0080] The focus sensor group includes three focus sensors 52; the first focus beam is projected onto one of the focus sensors 52 after passing through the third focus lens 513, the second focus beam is projected onto another focus sensor 52 after passing through the fourth focus lens 514, and the third focus beam is projected onto another focus sensor 52 after passing through the fifth focus lens 515.
[0081] The optical path difference element of this embodiment has different optical paths for the first focus beam, the second focus beam and the third focus beam to reach the focus sensor 52 . Therefore, there is a fixed optical path difference among the three in the optical path, and three focus images with different depths of field are formed on the three focus sensors 52 .
[0082] See also Figure 5-Figure 6Furthermore, a semi-reflective and semi-transparent film is coated on the incident surface of the triangular prism 503, and the autofocus microscopic imaging system also includes a review module 8. The review module 8 includes a review sensor 81 and a review lens 82. When the total focus light beam enters the triangular prism 503 from the incident surface, part of the light enters the triangular prism 503, and the other part of the light is reflected and enters the review sensor 81 through the review lens 82, and forms an image on the review sensor 81. The review sensor 81 is used to review the imaging of the imaging module 6. By introducing the review module 8, the imaging clarity of the imaging module 6 is reviewed, which effectively improves the imaging quality.
[0083] Example 4
[0084] See also Figure 5 This embodiment provides an auto-focus microscopic imaging system. The auto-focus microscopic imaging system in this embodiment is substantially the same as the auto-focus microscopic imaging system in Embodiment 1, except that the focus module 5 includes an optical path difference element, three sixth focus lenses 516 and a focus sensor group; the optical path difference element in this embodiment is a hexagonal prism 504.
[0085] One of the faces of the hexagonal prism 504 is the main incident face, and the faces on both sides of the main incident face are side incident faces; the other face opposite to the main incident face is the main exit face, and the faces on both sides of the main exit face are side exit faces. A reflective film is coated on the side exit face; in some embodiments, an anti-reflection film is coated on the side incident face. The total focus beam enters the hexagonal prism 504 from the direction directly opposite to the main incident face; part of the light enters the hexagonal prism 504 vertically from the main incident face, and is emitted from the main exit face to form a first focus beam; part of the light enters the hexagonal prism 504 from the side incident face, and is emitted from the main exit face after being reflected on the two side exit faces, forming a second focus beam and a third focus beam. The focus sensor group includes three focus sensors 52; the first focus beam, the second focus beam, and the third focus beam are projected into the focus sensor 52 after passing through the sixth focus lens 516, respectively.
[0086] Since the optical paths of the first focus beam, the second focus beam, and the third focus beam to the focus sensor 52 are different, there is a fixed optical path difference between the three in the optical path, and three focus images with different depths of field are formed on the three focus sensors 52. At the same time, the focus image generated by the first focus beam can also be used to review the imaging of the imaging module 6.
[0087] See also Figure 6In some other embodiments, the side incident surface of the hexagonal prism 504 is coated with a semi-reflective and semi-transparent film, the focus module 5 includes a total of five sixth focus lenses 516, and the focus sensor group includes five focus sensors 52. When part of the total focus beam enters the hexagonal prism 504 from the side incident surface, part of it enters the hexagonal prism 504, is reflected on the two side exit surfaces, and then is emitted from the main exit surface to form the second focus beam and the third focus beam; part of the light is reflected on the side incident surface to form the fourth focus beam and the fifth focus beam. The first focus beam, the second focus beam, the third focus beam, the fourth focus beam, and the fifth focus beam are respectively projected into the focus sensor 52 after passing through the sixth focus lens 516. At this time, five focus images with different depths of field are formed on the five focus sensors 52. At the same time, the focus image generated by the first focus beam can also be used to review the imaging of the imaging module 6. By adding focused images, the robustness of the focus prediction function is increased, and the accuracy of autofocus is improved.
[0088] Furthermore, the distance between each focus sensor 52 and the optical path difference element increases sequentially. In some embodiments, each focus sensor 52 is connected to a micro-motion element, and the distance between the focus sensor 52 and the optical path difference element is fine-tuned by the micro-motion element to adapt to detection scenarios with different accuracy requirements.
[0089] The automatic focusing microscopic imaging system of the utility model performs light splitting through an optical path difference element to form at least three focusing beams, thereby obtaining multiple quality statistical scoring curves. The accuracy of automatic focusing is improved, and the prediction of the focal depth position and the clear imaging of the microscopic imaging system can be more stably achieved. In addition, the optical path difference element is small in size and compact in structure, which can save space.
[0090] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.
Claims
1. A focusing module, characterized in that: include: An optical path difference element, wherein the optical path difference element receives and processes the total focused light beam to obtain at least three focused light beams with optical path differences; The optical path difference element is a triangular prism; The focus sensor group is used to receive the focus light beams respectively.
2. The focusing module according to claim 1, characterized in that: It also includes several focusing lenses; the triangular prism has an incident surface, a first exit surface and a second exit surface; the total focusing beam is emitted into the triangular prism from the incident surface, the triangular prism receives the total focusing beam and processes it to obtain a first focusing beam, a second focusing beam and a third focusing beam; the first focusing beam, the second focusing beam and the third focusing beam are respectively projected into the focusing sensor group through the focusing lenses.
3. The focusing module according to claim 2, characterized in that: The first exit surface is coated with a semi-reflective and semi-transparent film, and the focusing lens includes a third focusing lens and a fourth focusing lens; the total focusing light beam enters the triangular prism from the incident surface, and part of it is emitted to the first exit surface, and is reflected to generate a first split light beam; part of it is emitted to the second exit surface, and is reflected to generate a second split light beam; the first split light beam passes through the second exit surface to form the second focusing light beam; part of the second split light beam passes through the first exit surface to form the first focusing light beam, and part of it is reflected, returns to and passes through the second exit surface to form the third focusing light beam; the first focusing light beam passes through the third focusing lens and is projected into the focusing sensor group, and the second and third focusing light beams pass through the fourth focusing lens and are respectively projected into the focusing sensor group.
4. The focusing module according to claim 3, characterized in that: The first exit surface and the second exit surface are coated with a semi-reflective and semi-transparent film, and the focusing module includes a third focusing lens, a fourth focusing lens and a fifth focusing lens; the total focusing light beam enters the triangular prism from the incident surface, and part of it is emitted to the first exit surface, and is reflected to generate a first split light beam; part of it is emitted to the second exit surface, and is reflected to generate a second split light beam; the second split light beam passes through the first exit surface to form the first focusing light beam; the first split light beam is irradiated on the second exit surface, and part of it passes through the second exit surface to form the second focusing light beam; part of it is reflected, returns to and passes through the first exit surface to form the third focusing light beam; the first focusing light beam, the second focusing light beam and the third focusing light beam are respectively projected into the focusing sensor group after passing through the third focusing lens, the fourth focusing lens and the fifth focusing lens respectively.
5. An autofocus microscopic imaging system, characterized in that: include: A light source module, used for emitting a first light beam, wherein the first light beam is irradiated onto a sample to be tested to form an object light beam; an objective lens, used for shaping the first light beam and the object beam; A beam splitter element, used for splitting the object beam to obtain a total focus beam and an imaging beam; An imaging module, used for receiving the imaging light beam and performing imaging; The focusing module according to any one of claims 1 to 4.
6. An autofocus microscopic imaging system, characterized in that: include: A light source module, used for emitting a first light beam, wherein the first light beam is irradiated onto a sample to be tested to form an object light beam; an objective lens, used for shaping the first light beam and the object beam; A beam splitter element, used for splitting the object beam to obtain a total focus beam and an imaging beam; An imaging module, used for receiving the imaging light beam and performing imaging; The focusing module described in any one of claims 3-4, the incident surface of the triangular prism is coated with a semi-reflective and semi-transparent film, and the automatic focusing microscopic imaging system also includes a review module; the review module includes a review sensor and a review lens; when the total focusing light beam is incident from the incident surface, part of the light is incident on the triangular prism, and the other part of the light is reflected and enters the review sensor through the review lens for imaging.