An imaging system and focusing method

Abstract

This invention discloses an imaging system and a focusing method. The imaging system includes an aperture plate, an illumination module, and an imaging module. Light emitted by the illumination module passes through the aperture plate or is reflected by the aperture plate before entering the imaging module. It also includes a laser focusing module for assisting focusing. The illumination module comprises a fluorescent illumination module and a bright-field illumination module, which do not operate simultaneously. This invention also discloses a focusing method using the laser focusing module of the aforementioned imaging system. This invention integrates the fluorescent illumination module and the bright-field illumination module into the same imaging system. Different imaging results can be obtained by turning on the bright-field light source or the fluorescent light source as needed. The structure is simple and practical. Simultaneously, the focusing module uses the position / height of the objective lens for accurate focusing, which is simple, fast, and accurate, contributing to clearer imaging results.

Description

Technical Field

[0001] This invention relates to the field of imaging, and in particular to an imaging system and focusing method. Background Technology

[0002] During cell imaging, the information obtained under fluorescence imaging and bright field imaging are different. Sometimes, both types of imaging are needed to obtain complete information. Therefore, how to integrate the two illumination systems into the same imaging system is a challenge. In addition, focusing problems often occur during imaging. Existing built-in focusing systems are limited by the numerical aperture of the objective lens. After changing the objective lens, the resolution of laser focusing will change, which will increase the difficulty of use. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention discloses an imaging system and a focusing method.

[0004] An imaging system includes an aperture plate, an illumination module, and an imaging module. Light emitted by the illumination module is transmitted through the aperture plate or reflected by the aperture plate and then enters the imaging module. The system also includes a focusing module for laser-assisted focusing. The illumination module includes a fluorescent illumination module and a bright-field illumination module, which do not operate simultaneously.

[0005] Specifically, the fluorescent illumination module and the bright field illumination module are integrated into one system. Different imaging results can be obtained by turning on the bright field light source or the fluorescent light source as needed. The structure is simple and practical.

[0006] Preferably, the fluorescent illumination module includes a light source section and an illumination section. The light source section is used to combine light beams of different wavelengths and emit them into the illumination section. The illumination section includes a light homogenizing component, a first lens, and a second lens arranged sequentially along the optical path. The field stop is located between the first lens and the second lens. The field stop and the plane where the aperture plate is located form a 4F conjugate relationship.

[0007] Specifically, the plane containing the field stop and the aperture plate forms a 4F conjugate system, which achieves accurate matching of the shape and size between the illumination spot and the imaging area, effectively avoiding the beam illuminating non-target areas, greatly reducing signal crosstalk between adjacent background areas, and improving the accuracy and signal-to-noise ratio of quantitative imaging.

[0008] Preferably, the imaging module includes an objective lens, and the light-emitting surface of the light-monopolating component and the objective lens pupil form a 4F conjugate relationship.

[0009] Specifically, the beam is homogenized using a beam homogenizing component, and then the first and second lenses are used to image the light-emitting surface of the beam homogenizing component onto the objective lens pupil. This achieves uniform filling of the objective lens pupil by the beam, thereby obtaining a highly uniform illumination field and improving the efficiency of light energy collection and utilization.

[0010] Preferably, the light-diffusing component is a compound eye lens, which includes a plurality of microlens units, the size and arrangement of which are adapted to the size and shape of the objective lens pupil.

[0011] Specifically, the structure of using a compound eye lens for uniform light ensures that the light beam is uniform from the moment it enters the illumination section, thus eliminating the need for an aperture stop to adjust the uniformity of the light beam and further simplifying the structure of the illumination section. The structure in which the size and arrangement of the microlens units of the compound eye lens are adapted to the size and shape of the objective lens pupil ensures that the image of the light-emitting surface of the compound eye lens at the objective lens pupil can precisely and uniformly fill the entire objective lens pupil.

[0012] Preferably, the second lens and the objective lens are used to reduce the size of the field stop, so that the size of the field stop imaged on the plane of the aperture plate is smaller than the original size of the field stop.

[0013] Specifically, the second lens and objective lens reduce the field stop to form a smaller image, which can not only effectively improve the edge sharpness of the illumination spot, but also effectively improve the positioning accuracy of the illumination spot. In addition, in order to ensure that the imaging area of ​​the field stop can completely cover the area set for a single imaging, the imaging area of ​​the field stop is set to be larger than the single imaging area.

[0014] Preferably, the size of the field stop imaged on the plane of the aperture plate is 1 / 4 to 1 / 6 of the original size.

[0015] A focusing method employs a laser focusing module of an imaging system as described in any of the preceding claims. The laser focusing module includes a laser emitter, a cylindrical mirror, and a laser imaging camera. The laser emitter emits a point laser towards an orifice plate, the cylindrical mirror converts the point laser into a line laser, the cylindrical mirror is positioned between the laser emitter and the orifice plate, and the laser imaging camera images the laser reflected from the orifice plate. The method also includes a display module for displaying the laser imaging image.

[0016] Specifically, the point laser is converted into a line laser, which then shines on the perforated plate. The perforated plate reflects the line laser to form an image, which can more accurately show the location of the perforated plate.

[0017] Preferably, the following steps are used for focusing:

[0018] The laser focus position is preset and displayed on the display module;

[0019] The laser emitter is turned on so that the laser shines on the perforated plate. The laser imaging camera receives the laser reflected from the perforated plate and forms an image. The real-time position of the laser image is displayed on the display module.

[0020] The difference between the preset position and the real-time position of the line laser is obtained, and this difference is converted into a displacement. The objective lens of the imaging module is moved according to the displacement, and imaging is performed after the movement is completed.

[0021] Specifically, the position of the aperture plate corresponding to the preset laser focusing position is usually the optimal imaging position of the aperture plate. The point laser emitted by the laser emitter becomes a line laser after passing through the cylindrical mirror. The line laser illuminates the aperture plate, and the line laser reflected by the aperture plate enters the laser imaging camera to obtain the real-time position of the laser image. The real-time position is compared with the preset position to obtain the distance difference. The existence of a difference indicates that the height / position of the aperture plate has deviated from the optimal imaging height / position. In order to cover this deviation, the height / position of the aperture plate can be moved so that the real-time position of the aperture plate coincides with the preset position. However, in actual use, it is difficult to move the height / position of the aperture plate. Therefore, the solution provided in this paper is to fix the height / position of the aperture plate, calculate the displacement of the objective lens by the difference between the real-time position and the preset position, and achieve focusing by moving the height / position of the objective lens to cover the deviation.

[0022] Preferably, the display module is provided with coordinates, and the difference between the preset position and the actual position of the line laser is the coordinate difference between the two.

[0023] Preferably, the displacement of the objective lens Calculate using the following formula:

[0024]

[0025] in, It is the coordinate difference between the preset position and the real-time position of the linear laser. It refers to the pixel size of a laser imaging camera. It refers to the magnification of the imaging end of the laser focusing module. It is the angle at which the laser enters the orifice plate.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] By integrating the fluorescence illumination module and the bright field illumination module into the same imaging system, different imaging results can be obtained by turning on the bright field light source or the fluorescence light source as needed. The structure is simple and practical. At the same time, the focusing module is used to accurately focus by moving the position / height of the objective lens. The focusing is simple, fast and accurate, which helps to obtain clearer imaging results. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the imaging system disclosed in this invention. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, the imaging system disclosed in this invention includes a perforated plate 10, an illumination module, and an imaging module 20. The light emitted by the illumination module is transmitted through the perforated plate 10 or reflected by the perforated plate 10 and then enters the imaging module 20. It also includes a laser focusing module for assisting focusing. The illumination module includes a fluorescent illumination module 40 and a bright field illumination module 50. The fluorescent illumination module 40 and the bright field illumination module 50 do not work simultaneously.

[0031] The fluorescent illumination module 40 and the bright field illumination module 50 are integrated into one system. Different imaging results can be obtained by turning on the bright field light source or the fluorescent light source as needed. The structure is simple and practical.

[0032] Figure 1 In the process, the fluorescence emitted by the fluorescent illumination module 40 is reflected by the aperture plate 10 and then enters the imaging module 20 for imaging, while the bright field light emitted by the bright field illumination module 50 passes through the aperture plate 10 and then enters the imaging module 20 for imaging.

[0033] The fluorescent illumination module 40 includes a light source 41 and an illumination section. The light source 41 is used to combine light beams of different wavelengths and emit them into the illumination section. The illumination section includes a light homogenizing component 42, a first lens 43, and a second lens 44 arranged sequentially along the optical path. The field stop 45 is located between the first lens 43 and the second lens 44. The field stop 45 and the plane where the aperture plate 10 is located form a 4F conjugate relationship.

[0034] The plane containing the field stop 45 and the aperture plate 10 forms a 4F conjugate system, which achieves accurate matching of the shape and size between the illumination spot and the imaging area, effectively avoids the beam illuminating non-target areas, greatly reduces signal crosstalk between adjacent background areas, and improves the accuracy and signal-to-noise ratio of quantitative imaging.

[0035] The imaging module 20 includes an objective lens 21, and the light-emitting surface of the light-monopolating component 42 and the pupil of the objective lens 21 form a 4F conjugate relationship.

[0036] The beam is homogenized by the light homogenizing component 42, and then the light-emitting surface of the light homogenizing component 42 is imaged onto the pupil of the objective lens 21 by the first lens 43 and the second lens 44. This achieves uniform filling of the pupil of the objective lens 21 by the beam, thereby obtaining a highly uniform illumination field and improving the efficiency of light energy collection and utilization.

[0037] The light-diffusing component 42 is a compound eye lens, which includes several microlens units. The size and arrangement of the microlens units are adapted to the size and shape of the pupil of the objective lens 21.

[0038] The structure of using a compound eye lens for uniform light ensures that the light beam is uniform from the moment it enters the illumination section, thus eliminating the need for an aperture stop to adjust the uniformity of the light beam and further simplifying the structure of the illumination section. The structure in which the size and arrangement of the microlens units of the compound eye lens are adapted to the size and shape of the pupil of the objective lens 21 ensures that the image of the light-emitting surface of the compound eye lens at the pupil of the objective lens 21 can just evenly fill the entire pupil of the objective lens 21.

[0039] The second lens 44 and the objective lens 21 are used to reduce the size of the field stop 45 so that the size of the image formed by the field stop 45 on the plane of the aperture plate 10 is smaller than the original size of the field stop 45.

[0040] The second lens 44 and objective lens 21 reduce the image size of the field stop 45, which can not only effectively improve the edge sharpness of the illumination spot, but also effectively improve the positioning accuracy of the illumination spot. In addition, in order to ensure that the imaging area of ​​the field stop 45 can completely cover the set single imaging area, the imaging area of ​​the field stop 45 is set to be larger than the set single imaging area.

[0041] The size of the image formed by the field stop 45 on the plane containing the aperture plate 10 is 1 / 4 to 1 / 6 of the original size.

[0042] The present invention also discloses a focusing method, which uses the laser focusing module of the aforementioned imaging system for focusing. The laser focusing module includes a laser emitter 31, a cylindrical mirror 32, and a laser imaging camera 33. The laser emitter 31 is used to emit a point laser to the orifice plate 10, the cylindrical mirror 32 is used to convert the point laser into a line laser, the cylindrical mirror 32 is disposed between the laser emitter 31 and the orifice plate 10, and the laser imaging camera 33 is used to image the laser reflected by the orifice plate 10. It also includes a display module for displaying the laser imaging image.

[0043] The point laser is converted into a line laser, which then illuminates the orifice plate 10. The orifice plate 10 reflects the line laser to form an image, which can more accurately show the location of the orifice plate 10.

[0044] Structurally, focusing can be achieved regardless of whether the laser focusing module is fixed or movable. When the laser focusing module is fixed ( Figure 1(As shown in this case), the laser emitter 31 is positioned diagonally below the aperture plate 10, and the laser beam enters the aperture plate 10 at an angle. The laser imaging camera 33 is positioned in the optical path of the laser beam reflected from the aperture plate 10. When the laser focusing module is movable, the laser emitter 31 and the laser imaging camera 33 are directly or indirectly fixed to the objective lens 21 and move with the objective lens 21. The fixed-position laser focusing module is easier to install, while the movable laser focusing module allows for real-time observation of the focusing status on the display module, thus providing a good focusing effect.

[0045] To focus, follow these steps:

[0046] The laser focus position is preset and displayed on the display module;

[0047] The laser emitter 31 is turned on so that the laser shines on the perforated plate 10. The laser imaging camera 33 receives the laser reflected from the perforated plate 10 and performs imaging. The real-time position of the laser imaging is displayed on the display module.

[0048] The difference between the preset position and the real-time position of the line laser is obtained, and the difference is converted into a displacement. The objective lens 21 of the imaging module 20 is moved according to the displacement, and imaging is performed after the movement is completed.

[0049] Typically, the position of the aperture plate 10 corresponding to the preset laser focusing position is the optimal imaging position of the aperture plate 10. The point laser emitted by the laser emitter 31 becomes a line laser after passing through the cylindrical mirror 32. The line laser illuminates the aperture plate 10, and the line laser reflected by the aperture plate 10 enters the laser imaging camera 33 to form an image, obtaining the real-time position of the laser image. The real-time position is compared with the preset position to obtain the distance difference. The existence of a difference indicates that the height / position of the aperture plate 10 has deviated from the optimal imaging height / position. In order to cover this deviation, the height / position of the aperture plate 10 can be moved so that the real-time position of the aperture plate 10 coincides with the preset position. However, in actual use, it is difficult to move the height / position of the aperture plate 10. Therefore, the solution provided in this solution is to fix the height / position of the aperture plate 10, calculate the displacement of the objective lens 21 by the difference between the obtained real-time position and the preset position, and achieve focusing by moving the height / position of the objective lens 21 to cover the deviation.

[0050] The display module has coordinates, and the difference between the preset position and the actual position of the line laser is the coordinate difference between the two.

[0051] Displacement of objective lens 21 Calculate using the following formula:

[0052]

[0053] in, It is the coordinate difference between the preset position and the real-time position of the linear laser. It is the pixel size of a laser imaging camera. It refers to the magnification of the imaging end of the laser focusing module. It is the angle at which the laser enters the through-hole plate at angle 10.

Claims

1. An imaging system, comprising a perforated plate, an illumination module, and an imaging module, wherein light emitted by the illumination module passes through the perforated plate or is reflected by the perforated plate and then enters the imaging module, characterized in that, It also includes a laser focusing module for assisting focusing, and the illumination module includes a fluorescent illumination module and a bright field illumination module, wherein the fluorescent illumination module and the bright field illumination module do not work simultaneously.

2. The imaging system according to claim 1, characterized in that, The fluorescent illumination module includes a light source and an illumination section. The light source is used to combine light beams of different wavelengths and emit them into the illumination section. The illumination section includes a light homogenizing component, a first lens, and a second lens arranged sequentially along the optical path. The field stop is located between the first lens and the second lens. The field stop and the plane where the aperture plate is located form a 4F conjugate relationship.

3. The imaging system according to claim 2, characterized in that, The imaging module includes an objective lens, and the light-emitting surface of the light-monopolating component forms a 4F conjugate relationship with the objective lens pupil.

4. The imaging system according to claim 2, characterized in that, The light-diffusing component is a compound eye lens, which includes several microlens units. The size and arrangement of the microlens units are adapted to the size and shape of the objective lens pupil.

5. The imaging system according to claim 1, characterized in that, The second lens and objective lens are used to reduce the size of the field stop, so that the size of the field stop imaged on the plane of the aperture plate is smaller than the original size of the field stop.

6. The imaging system according to claim 5, characterized in that, The size of the field stop imaged on the plane of the aperture plate is 1 / 4 to 1 / 6 of the original size.

7. A focusing method, characterized in that, The imaging system according to any one of claims 1-6 is used for focusing. The laser focusing module includes a laser emitter, a cylindrical mirror, and a laser imaging camera. The laser emitter is used to emit a point laser to the aperture plate. The cylindrical mirror is used to convert the point laser into a line laser. The cylindrical mirror is disposed between the laser emitter and the aperture plate. The laser imaging camera is used to image the laser reflected by the aperture plate. The system also includes a display module for displaying the laser imaging image.

8. The focusing method according to claim 7, characterized in that, To focus, follow these steps: The laser focus position is preset and displayed on the display module; The laser emitter is turned on so that the laser shines on the perforated plate. The laser imaging camera receives the laser reflected from the perforated plate and forms an image. The real-time position of the laser image is displayed on the display module. The difference between the preset position and the real-time position of the line laser is obtained, and this difference is converted into a displacement. The objective lens of the imaging module is moved according to the displacement, and imaging is performed after the movement is completed.

9. The focusing method according to claim 8, characterized in that, The display module is equipped with coordinates, and the difference between the preset position and the actual position of the line laser is the coordinate difference between the two.

10. The focusing method according to claim 9, characterized in that, objective lens displacement Calculate using the following formula: in, It is the coordinate difference between the preset position and the real-time position of the linear laser. It refers to the pixel size of a laser imaging camera. It refers to the magnification of the imaging end of the laser focusing module. It is the angle at which the laser enters the orifice plate.

Images