Microscopic imaging system and focusing method thereof

Abstract

The invention provides a microscopic imaging system and a focusing method thereof, the microscopic imaging system comprises two imaging channels, and each imaging channel is provided with a first light source, a relay assembly, an objective lens and a first imaging module; the first light source is used for generating first light signals; the relay assembly is used for projecting the first optical signal to the objective lens; the objective lens is arranged between the relay assembly and the sample and used for converging the first optical signal to the sample and projecting the first optical signal reflected by the sample to the first imaging module along the relay assembly; the first imaging module is used for imaging the first optical signal; in the two groups of imaging channels, one group of objective lenses converge the first optical signals on the front surface of the sample, and the other group of objective lenses converge the first optical signals on the back surface of the sample; the microscopic imaging system provided by the invention meets the acquisition of different surface image signals of the sample, and meanwhile, the focusing operation of the objective lens and the sample in the microscopic imaging system can be conveniently realized by utilizing the focusing method provided by the invention.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of imaging technology, in particular to a microscopic imaging system and a focusing method thereof. BACKGROUND

[0002] Most of the current microscopic imaging systems perform single-channel imaging, while in complex multi-channel imaging microscopic systems, the combination of normal incidence and oblique incidence is mostly used to perform single imaging detection on the single surface of the sample.

[0003] The upper and lower surfaces of some samples have different effective information and both need to be detected. At this time, the existing microscopic imaging system needs to expose the different surfaces of the sample to the imaging channel by manually turning over the sample. In addition, due to the difference in the concave-convex condition or shape profile of the two surfaces of the sample, sometimes the sample surface and the objective lens need to be refocused again. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings mentioned in the background art and provide a microscopic imaging system and a focusing method thereof.

[0005] In one aspect, the present application provides a microscopic imaging system, comprising two groups of imaging channels, each group of imaging channels having a first light source, a relay assembly, an objective lens and a first imaging module; The first light source is used to generate a first light signal; The relay assembly is used to project the first light signal to the objective lens; The objective lens is arranged between the relay assembly and the sample, used to converge the first light signal to the sample, and project the first light signal reflected by the sample to the first imaging module along the relay assembly; The first imaging module is used for imaging the first light signal; In the two groups of imaging channels, one group of objective lenses converges the first light signal to the front surface of the sample, and the other group of objective lenses converges the first light signal to the back surface of the sample.

[0006] In the microscopic imaging system of the present application, two groups of imaging channels are provided, and the objective lenses in the two groups of imaging channels can obtain image signals of the front and back surfaces of the sample and image them to the first imaging module respectively, satisfying the acquisition of image signals of different surfaces of the sample; and without turning over and adjusting the sample and refocusing twice during the process, the operation is convenient and fast.

[0007] Further, for some semi-transparent samples, the upper and lower surface images are not easy to distinguish when detected in one direction. To solve this problem, the first light signal is transmitted through the sample to form a transmission signal; The objective lens, the relay assembly and the first imaging module in any one of the imaging channels are located on the exit light path of the transmission signal in the other imaging channel, so that the transmission signal in any one of the imaging channels can be imaged onto the first imaging module in the other imaging channel, and the transmission image of the sample can be obtained.

[0008] Further, the relay assembly comprises a first beam splitter, which is used for reflecting the first light signal to the objective lens and transmitting the first light signal reflected by the sample and passing through the objective lens to the first imaging module, so as to realize the acquisition of the sample image.

[0009] Further, the relay assembly further comprises one or more of a relay mirror, a tube lens, a condenser lens, a filter and a prism, which can be selected and arranged according to the relay requirement.

[0010] Further, each objective lens is further connected with a displacement module, which is used for adjusting the distance between the objective lens and the sample, so that the objective lens can be focused on the sample.

[0011] Further, each imaging channel is further provided with a focusing assembly, and the focusing assembly comprises a second light source, a second beam splitter, a second imaging module, a focusing light path and a reference light path. The second light source is used for generating a second light signal. The second beam splitter is used for splitting the second light signal into a focusing light signal and a reference light signal. The focusing light path is used for converging the focusing light signal to the sample surface through the objective lens, and projecting the focusing light signal reflected by the sample and passing through the objective lens to the second imaging module. The reference light path is used for projecting the reference light signal to a set of first reflection modules, and projecting the reference light signal reflected by the first reflection modules to the second imaging module. The second imaging module is used for imaging the focusing light signal and the reference light signal, and realizes the focusing between the objective lens and the sample in combination with the focusing light signal and the reference light signal.

[0012] Further, the focusing light path has a second reflection module and a third reflection module, and the second reflection module and the third reflection module are used for conducting the focusing light path between the second beam splitter and the objective lens.

[0013] Further, the first reflection module is a double-sided mirror, and two sets of reflecting surfaces of the double-sided mirror are respectively used for reflecting the reference light signal in a set of focusing assemblies.

[0014] Further, the focusing assembly further comprises a fourth reflection module, which is used for conducting the reference light path between the second beam splitter and the first reflection module.

[0015] On the other hand, the application further provides a focusing method of the foregoing microscopic imaging system, and the focusing method comprises: The interval between the objective lens and the sample is adjusted by the displacement module to change the optical path difference of the focusing light signal and the reference light signal; when the interference image amplitude of the focusing light signal and the reference light signal on the second imaging module is maximum, the objective lens is focused on the sample, and the focusing operation between the objective lens and the sample in the two imaging channels can be conveniently realized. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A structural block diagram of a microscopic imaging system provided by the embodiment of the present application is provided. Figure 2 A light path principle diagram of a microscopic imaging system provided by the embodiment of the present application is provided. Figure 3 A waveform diagram of the reference light signal and the focusing light signal superimposed in the embodiment of the present application is provided. Among them, the icon meanings are as follows: 1-first light source, 2-relay assembly, 201-first beam splitter, 202-tube lens, 3-objective lens, 4-displacement module, 5-sample, 6-first imaging module, 7-bidirectional focusing module, 701-second light source, 702-second beam splitter, 703-first reflection module, 704-fourth reflection module, 705-second imaging module, 8-focusing light path, 801-second reflection module, 802-third reflection module. DETAILED DESCRIPTION

[0017] The principles and characteristics of the present application are described below, and the examples are only used to explain the present application, and are not used to limit the scope of the present application.

[0018] Embodiment one: Reference Figure 1 and Figure 2 The embodiment provides a microscopic imaging system, which comprises two imaging channels, each of which has a first light source 1, a relay assembly 2, an objective lens 3 and a first imaging module 6.

[0019] The first light source 1 is used for generating a first light signal; The relay assembly 2 is used for projecting the first light signal to the objective lens 3; The objective lens 3 is arranged between the relay assembly 2 and the light path of the sample 5, and is used for converging the first light signal to the sample 5; after the first light signal reflected by the sample 5 passes through the objective lens 3 and the relay assembly 2, it is projected to the first imaging module 6; The first imaging module 6 is used for imaging the first light signal; In the two imaging channels, one objective lens 3 converges the first light signal to the front surface of the sample 5, and the other objective lens 3 converges the first light signal to the back surface of the sample 5.

[0020] Therefore, the objective lens 3 in the two imaging channels focuses on one side of the sample 5, and the image signals of the front and back sides of the sample 5 can be acquired and imaged on the first imaging module 6, so that the image signals of different surfaces of the sample 5 are acquired without flipping the sample 5 and focusing twice, and the operation is convenient and fast.

[0021] The first light source 1 can be one or more light emitting elements, which can be selected from argon arc lamps, halogen lamps, LEDs, and other incoherent light sources or lasers and other coherent light sources. In addition, the first light source 1 can also be an illumination system for beam shaping. For example, the illumination system includes one or more light emitting elements and an optical assembly for shaping the light beams generated by the one or more light emitting elements. According to actual needs, the optical assembly can include one or more lenses and / or mirrors, which will not be described here.

[0022] In addition, the two imaging channels can be independently provided with a set of the first light source 1 as described above, or the first light source 1 in the two imaging channels can be formed by one or more light emitting elements, or the first light source 1 in the two imaging channels can also be formed by splitting the light beams generated by an illumination system.

[0023] The relay assembly 2 is used to relay the first light signal generated by the first light source 1 to the objective lens 3 and relay the first light signal reflected by the sample 5 to the first imaging module 6. According to needs, the relay assembly 2 can include one or more relay mirrors, tube lenses 202, light collectors, filters, and prisms.

[0024] The first imaging module 6 can be an imaging system with a CCD, TDI, CMOS, or other sensor device or a light screen, and the two imaging channels can be provided with a set of the first imaging module 6.

[0025] Alternatively, the two imaging channels can share a set of the first imaging module 6, in which case only the first light signals reflected by the front and back sides of the sample 5 need to pass through the relay assembly 2 and then be guided to the same set of the first imaging module 6 through the corresponding optical path structure.

[0026] For example, in this embodiment, the relay assembly 2 includes a first beam splitter 201 and a set of tube lenses 202. The first light signal emitted by the first light source 1 is reflected by the first beam splitter 201, then passes through the set of tube lenses 202 and the set of objective lenses 3, and converges on the surface of the sample 5. The first light signal reflected by the sample 5 passes through the objective lens 3 and the tube lens 202 and is transmitted through the first beam splitter 201. The first light signal transmitted through the first beam splitter 201 is imaged on the first imaging module 6.

[0027] Embodiment two: For some semi-transparent sample 5, the upper and lower surface images are not distinguishable in the unidirectional detection. To solve this problem, in the microscopic imaging system in Embodiment One, the first light signal in any one group of imaging channels can form a transmission signal by transmitting the sample 5; Wherein, the objective lens 3, the relay assembly 2 and the first imaging module 6 in any one group of imaging channels are located on the exit light path of the transmission signal in the other group of imaging channels, so that the transmission signal in any one group of imaging channels can be imaged onto the first imaging module 6 in the other group of imaging channels, and the transmission image of the sample 5 can be obtained.

[0028] Therefore, the microscopic imaging system in the embodiment can obtain the front reflection image, the back reflection image and the transmission image in any direction along the front and back surfaces of the sample 5.

[0029] In Embodiment One or Embodiment Two, when the objective lens 3 focuses on the surface of the sample 5 and the distance between the objective lens 3 and the sample 5 is not adjustable, this case can be used for image acquisition of a type of sample 5 with good thickness consistency; or, the distance between the objective lens 3 and the sample 5 is adjustable, and this case can be used for image acquisition of the objective lens 3 on samples 5 with different thicknesses.

[0030] When the distance between the objective lens 3 and the sample 5 is adjustable, the sample 5 can be fixed in position and the distance between the objective lens 3 in the two groups of imaging channels and the sample 5 can be adjusted.

[0031] Alternatively, the sample 5 and the objective lens 3 in the two groups of imaging channels can be adjustably moved along the optical axis direction of the first light signal, and the two objective lenses 3 can also focus on the front and back surfaces of the sample 5, but this will make the focusing operation of the sample 5 and the objective lens 3 more complicated.

[0032] Embodiment Three: On the basis of Embodiment Two, in the embodiment, the position of the sample 5 is relatively fixed, and each objective lens 3 is further connected with a displacement module 4. The displacement module 4 is mainly used for adjusting the displacement amount of the objective lens 3, i.e. adjusting the distance between the objective lens 3 and the sample 5, so that the objective lens 3 can focus on the sample 5; therefore, the displacement module 4 can adopt a manual or electric displacement platform such as a focusing screw or a six-axis fine adjustment frame.

[0033] By adjusting the distance between the objective lens 3 and the sample 5, the focusing and defocusing of the objective lens 3 on the surface of the sample 5 can be realized.

[0034] Embodiment Four: On the basis of Embodiment Three, in the microscopic imaging system provided by the application, each group of imaging channels is further configured with a focusing assembly, and the two focusing assemblies are integrated in a bidirectional focusing module 7. Each focusing assembly includes a second light source 701, a second beam splitter 702, a second imaging module 705, a focusing light path 8 and a reference light path.

[0035] The second light source 701 is configured to generate a second light signal.

[0036] The second beam splitter 702 is configured to split the second light signal into a focusing light signal and a reference light signal, one of which is reflected by the second beam splitter 702 and the other of which is transmitted by the second beam splitter 702.

[0037] The focusing light path 8 is configured to converge the focusing light signal to the surface of the sample 5 through the objective lens 3, and project the focusing light signal reflected by the sample 5 and passing through the objective lens 3 to the second imaging module 705. The reference light path is configured to project the reference light signal to the first reflection module 703, and project the reference light signal reflected by the first reflection module 703 to the second imaging module 705. The second imaging module 705 is configured to image the focusing light signal and the reference light signal, and realize the focusing between the objective lens 3 and the sample 5 by combining the focusing light signal and the reference light signal.

[0038] Specifically, referring to Figure 2 The second light source 701 is configured to generate a second light signal, which can be an independent coherent light source, or the second light source 701 can be a coherent light source formed by splitting the first light source 1 through another beam splitter before or after splitting by the first beam splitter 201.

[0039] It is easy to understand that when the second light source 701 and the first light source 1 are split by a beam splitter, in the focusing process, in order to avoid the interference of the first light source 1, the first light signal can be blocked by a corresponding light shielding structure to avoid entering and exiting the objective lens 3.

[0040] Referring to Figure 2 In the embodiment, the second light signal emitted by the second light source 701 transmits the reference light signal and reflects the focusing light signal through the second beam splitter 702.

[0041] It is easy to understand that a set of first reflection modules 703 can be arranged in the focusing assembly of each of the two sets of imaging channels; referring to Figure 2 In the embodiment, the first reflection module 703 is a double-sided mirror, so the reference light signal in the two sets of focusing assemblies can be projected to one side of the double-sided mirror, and the reference light paths in the two sets of focusing assemblies are arranged symmetrically outside the two sides of the double-sided mirror.

[0042] In this embodiment, the focusing optical path 8 has a second reflection module 801 and a third reflection module 802. The second reflection module 801 and the third reflection module 802 are used to connect the focusing optical path 8 between the second beam splitter 702 and the objective lens 3. That is, in each group of focusing optical paths 8, the focusing light signal reflected by the second beam splitter 702 passes through the second reflection module 801 and the third reflection module 802 in sequence and reaches the objective lens 3, and is then projected onto the surface of the sample 5 by the objective lens 3. The focusing light signal reflected from the surface of the sample 5 then travels along the objective lens 3, the third reflection module 802 and the second reflection module 801 to the second beam splitter 702. Then, the focusing light signal is transmitted through the second beam splitter 702 to reach the second imaging module 705.

[0043] The second reflection module 801 can be a reflector or a total reflection lens. In this embodiment, since the third reflection module 802 participates in the imaging optical path of the imaging channel, the third reflection module 802 adopts a beam splitter structure so that the first optical signal in the imaging channel can be transmitted through the third reflection module 802.

[0044] In some embodiments, when the wavelengths of the first light source 1 and the second light source 701 are different, the third reflection module 802 may also be a dichroic mirror, transmitting the first light signal and reflecting the focusing light signal.

[0045] In this embodiment, the third reflection module 82 is located between the objective lens 3 and the tube lens 202.

[0046] In this embodiment, since the two sets of focusing components share a single double-sided mirror, in order for the reference light signal transmitted by the second beam splitter 702 to be projected onto one side of the double-sided mirror, the reference... Figure 2 A fourth reflection module 704 is provided in the reference optical path of the second beam splitter 702 and the double-sided mirror. The reference light signal reflected by the first reflection module 703 passes through the fourth reflection module 704 and the second beam splitter 702 in sequence before reaching the second imaging module 705.

[0047] The fourth reflection module 704 can be a reflector or a total reflection lens, and the second imaging module 705 can be an imaging system or a screen with sensors such as CCD, TDI, and CMOS.

[0048] Reference Figure 2 In this embodiment, the second reflection module 801, the third reflection module 802, and the objective lens 3 are integrated on a set of displacement modules 4.

[0049] Example 5: This embodiment provides a focusing method for a microscopic imaging system, which uses the microscopic imaging system provided in Embodiment 4.

[0050] The focusing methods include: In each imaging channel, the distance between the objective lens 3 and the sample 5 is adjusted by the displacement module 4 to change the optical path of the focus light signal, and the change of the optical path difference between the focus light signal and the reference light signal changes the amplitude of the interference signal formed by the superposition of the focus light signal and the reference light signal; When the optical path difference between the reference light signal and the focus light signal approaches zero, at this time, the amplitude of the interference image on the second imaging module 705 is maximum, and the objective lens 3 is focused on the sample 5.

[0051] When the second imaging module 705 uses a detector, refer to Figure 3 When the amplitude of the superposition of the focus light signal and the reference light signal waveform is maximum, the objective lens 3 is focused on the sample 5.

[0052] When the second imaging module 705 uses a light screen, when the bright and dark fringes in the interference fringes of the reference light signal and the focus light signal on the light screen are the most intense, the objective lens 3 is focused on the sample 5.

[0053] In the microscopic imaging system provided by the application, two focusing assemblies are integrated on a bidirectional focusing module 7, and the focusing of the objective lens 3 in the two imaging channels can be completed by using a bidirectional focusing module 7, which has the advantages of high precision, fast speed, small space, low cost and the like.

[0054] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0055] In addition, the terms "first", "second", "third" and "fourth" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third" and "fourth" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A microscopic imaging system, characterized in that, It includes two imaging channels, each of which has a first light source, a relay component, an objective lens, and a first imaging module; The first light source is used to generate the first light signal; The relay component is used to project the first optical signal onto the objective lens; The objective lens is positioned between the relay component and the sample, and is used to converge the first light signal onto the sample, and project the first light signal reflected from the sample along the relay component onto the first imaging module; The first imaging module is used for imaging the first optical signal; In the two sets of imaging channels, one set of objectives focuses the first light signal onto the front of the sample, and the other set of objectives focuses the first light signal onto the back of the sample.

2. The microscopic imaging system according to claim 1, characterized in that, The first optical signal is transmitted through the sample to form a transmission signal; The objective lens, relay component, and first imaging module in any one set of imaging channels are all located on the outgoing light path of the transmitted signal in another set of imaging channels, so that the transmitted signal in any one set of imaging channels can be imaged onto the first imaging module in another set of imaging channels.

3. The microscopic imaging system according to claim 2, characterized in that, The relay component includes a first beam splitter, which is used to reflect the first optical signal to the objective lens and transmit the first optical signal, after being reflected by the sample and passing through the objective lens, to the first imaging module.

4. The microscopic imaging system according to claim 3, characterized in that, The relay assembly also includes one or more of the following: relay mirror, tube mirror, light-collecting mirror, filter, and prism.

5. The microscopic imaging system according to claim 1, 2, 3 or 4, characterized in that, Each objective lens is also connected to a displacement module, which is used to adjust the distance between the objective lens and the sample.

6. The microscopic imaging system according to claim 5, characterized in that, Each of the imaging channels is also equipped with a focusing component, which includes a second light source, a second beam splitter, a second imaging module, a focusing optical path, and a reference optical path. The second light source is used to generate the second light signal; The second beam splitter is used to split the second optical signal into a focusing optical signal and a reference optical signal; The focusing optical path is used to converge the focusing light signal onto the sample surface via the objective lens, and project the focusing light signal reflected from the sample and passed through the objective lens onto the second imaging module; The reference optical path is used to project the reference optical signal onto a set of first reflection modules, and to project the reference optical signal reflected by the first reflection modules onto the second imaging module; The second imaging module is used for imaging the focusing light signal and the reference light signal.

7. The microscopic imaging system according to claim 6, characterized in that, The focusing optical path has a second reflection module and a third reflection module, which are used to connect the focusing optical path between the second beam splitter and the objective lens.

8. The microscopic imaging system according to claim 6, characterized in that, The first reflection module is a double-sided reflector, and each of the two sets of reflective surfaces of the double-sided reflector is used to reflect a set of reference light signals in the focusing assembly.

9. The microscopic imaging system according to claim 8, characterized in that, The focusing assembly further includes a fourth reflection module, which is used to connect the reference optical path between the second beam splitter and the first reflection module.

10. A focusing method for a microscopic imaging system, characterized in that, Using the microscopic imaging system according to any one of claims 6 to 9, the focusing method includes: The distance between the objective lens and the sample is adjusted by the displacement module to change the optical path difference between the focusing light signal and the reference light signal; When the amplitude of the interference image between the focusing light signal and the reference light signal on the second imaging module is at its maximum, the objective lens focuses on the sample.

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