Miniaturized phase contrast microscopic imaging device based on gradient refractive index lens

Abstract

The invention discloses a miniaturized phase contrast microscopic imaging device and method based on a gradient refractive index lens, and the method is characterized in that light emitted by a monochromatic LED light source is changed into parallel light after passing through a hemispherical lens, and then enters a self-focusing lens through an annular diaphragm and a beam splitter to be converged on a sample; and the reflected signal light focuses a phase enhanced signal on the memory through the tube lens and the phase plate to complete the imaging process. According to the phase contrast microscopic imaging device, phase information of an object is converted into corresponding amplitude information through the phase plate, and the phase information of the object is converted into observable light intensity distribution on an imaging surface, so that the distinguishability of the transparent object is greatly improved. The miniaturized phase contrast microscopic imaging system is designed by combining a series of miniaturized optical elements and memories through the characteristics of small size and high imaging quality of the self-focusing lens, so that the quality and the cost of the system are greatly reduced, and the application range of the system is expanded.

Description

Technical Field

[0001] The present invention relates to a miniaturized phase contrast microscopic imaging device and method, and in particular to a miniaturized phase information enhancement device and method based on a gradient refractive index lens. Currently, miniaturized microscopic imaging technology has the advantages of small size and large imaging field of view. By combining the core component gradient refractive index lens with the miniaturized phase contrast element and changing the image transmission mode, phase information enhancement detection can be realized under various application conditions. Background Art

[0002] Phase contrast microscopy was first proposed by Dutch physicist Frits Zernike in 1934. It is a contrast-enhancing optical technique that can be used to produce high-contrast images of transparent samples, such as living cells, microorganisms, thin tissue sections, etc. Simply put, this phase contrast technique uses an optical mechanism to convert small changes in phase into corresponding amplitude changes, which can be visualized as differences in image contrast. Moreover, the main advantage of phase contrast microscopy is that living cells can be examined in their natural state without having to be killed, fixed, and stained in advance. Therefore, the dynamics of ongoing biological processes can be observed and recorded. The optical mechanism used is phase shift and then interference. When light passes through a dense medium, in addition to the reduction in speed, if the two waves meet at one point, coherent destructive interference will occur, and the intensity reduction can be converted into an amplitude change of light.

[0003] The original intention of the miniaturized microscope (Miniscope) was to better image and observe the brain of freely moving mice. Since the invention of the optical microscope, the pursuit of multifunctional in vivo microscopes has been continuous. Living cell observations such as culture dishes are already very mature, but in vivo imaging of mammals still faces great challenges. Among mammalian species, mice are an excellent and tenacious genetic model for targeted manipulation of cell characteristics, but when using an optical microscope to observe their brains, their limbs and heads still need to be fixed, and the objective lens is fixed above the head for observation. This restriction on their normal behavior and activities will greatly affect the universality of obtaining information. The improvement of manufacturing technology is the most critical progress in miniaturization integration. Gradient refractive index lenses replace traditional objective lenses, small-size optical components replace conventional-size optical components, and all optical components are integrated in a 3D-printed housing. A miniaturized microscope that can be worn on the head came into being. However, it is only used in fluorescence microscopy imaging systems, and other imaging methods have not been developed. Miniscope is not only small in size, but also has micron-level resolution and millimeter-level field of view. Through adaptive improvements, it can be applied to biological or industrial detection under special conditions. Summary of the invention

[0004] A brief overview of the present invention is provided below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0005] In view of this, in order to overcome the above-mentioned technical problems, the present invention provides a miniaturized phase contrast microscopy imaging device and method based on a gradient refractive index lens. By using a gradient refractive index lens instead of a single objective lens, optical elements can be highly integrated while ensuring resolution and field of view, thereby reducing the volume of the edge-enhanced microscopy imaging device.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] Solution 1: The present invention provides a miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens, characterized in that it includes an illumination module, a phase amplitude conversion module, and a miniaturized imaging acquisition module;

[0008] The illumination module comprises, in order according to the light propagation direction: a monochromatic light source, a hemispherical lens, an annular aperture, a beam splitter, a self-focusing lens, a beam splitter, a tube lens, a phase plate and a memory;

[0009] The phase amplitude conversion modules are, in order according to the light propagation direction: an annular aperture, a beam splitter, a self-focusing lens, a beam splitter, a tube lens, and a phase plate;

[0010] The miniaturized acquisition modules are, in order according to the light propagation direction: a tube lens, a phase plate and a memory;

[0011] Furthermore: the monochromatic light source is closely attached to the hemispherical lens, ensuring that the volume is compressed to the maximum extent while the light source is transformed from a spherical wave into parallel light.

[0012] Furthermore: the size of the annular aperture is 4mm×4mm×2mm, the size of the phase plate is 4mm×4mm×2mm, and the size of the beam splitter is 4mm×4mm×3mm.

[0013] Furthermore: the gradient refractive index lens has NA (numerical aperture) = 0.5, f = 0.2 mm, a diameter of 2 mm, and a length of 10 mm.

[0014] Furthermore: the self-focusing lens, annular aperture, hemispherical lens, monochromatic light source, memory, phase plate, tube lens and beam splitter are all integrated in the housing of the miniaturized microscopic imaging system made of 3D-printed optical resin.

[0015] Furthermore: the tube lens has a focal length of f=6 mm and a diameter of D=5 mm, and is used to converge the light emitted by the sample onto the photosensitive surface of the storage device.

[0016] Furthermore: the miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens is characterized in that the memory pixel size is 6 μm and the field of view can reach 700×700 μm.

[0017] Furthermore: the device has a total length of 20 mm, a width of 15 mm×15 mm, and a mass of only 3 g, and can be easily fixed on a multi-axis robotic arm to achieve lateral movement, axial movement, and coaxial rotation.

[0018] Further: the annular aperture is constructed as an opaque flat black (light absorbing) plate with a transparent annular ring, which is located in the front focal plane (aperture) of the condenser, so that the sample can be illuminated by the defocused, parallel light wavefronts emitted from the ring. The microscope condenser images the annular aperture at infinity.

[0019] Further: The phase plate comprises a ring etched in glass with reduced thickness to push the phase difference of the surround (S) wave by a quarter wavelength. Typically, the ring is also coated with a partially absorbing metal film to reduce the amplitude of the surround light by 60%-90%.

[0020] Beneficial Effects

[0021] The miniaturized phase contrast microscopy imaging device and method based on the gradient refractive index lens of the present invention has the advantages of small size, large imaging field of view, high resolution and enhanced phase information, and can clearly image transparent phase samples under non-staining conditions. Different from the large mass and volume characteristics of traditional desktop phase contrast microscopes, the present invention is very suitable as an integrated scientific research payload with its excellent volume-mass characteristics, and is used in various biological detection or industrial detection fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a miniaturized phase contrast microscopic imaging device based on a gradient refractive index lens of the present invention.

[0023] In the figure: 1 gradient refractive index lens, 2 annular aperture, 3 hemispherical lens, 4 monochromatic light source, 5 housing, 6 memory, 7 phase plate, 8 tube lens, 9 beam splitter. DETAILED DESCRIPTION

[0024] Exemplary embodiments of the present invention will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the disclosure of the present invention.

[0025] It is also necessary to explain here that, in order to avoid obscuring the present invention due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0026] Embodiment 1: As attached Figure 1 The embodiment shown provides a miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens, which is used to achieve phase information enhanced detection.

[0027] A miniaturized phase contrast microscopic imaging device based on a gradient refractive index lens, characterized in that it comprises an illumination module, a phase amplitude conversion module, and a miniaturized imaging acquisition module;

[0028] The illumination module is composed of, in order of light propagation direction: a monochromatic light source 4, a hemispherical lens 3, an annular aperture 2, a beam splitter 9, a self-focusing lens 1, a beam splitter 9, a tube lens 8, a phase plate 7 and a memory 6;

[0029] The phase amplitude conversion module is arranged in the following order according to the light propagation direction: annular aperture 2, beam splitter 9, self-focusing lens 1, beam splitter 9, tube lens 8, phase plate 7;

[0030] The miniaturized acquisition modules are, in order according to the light propagation direction: a tube lens 8, a phase plate 7 and a memory 6;

[0031] More specifically: the monochromatic light source 4 is closely attached to the hemispherical lens 3, ensuring that the volume is compressed to the maximum extent while the light source is transformed from a spherical wave into parallel light.

[0032] More specifically: the size of the annular aperture 2 is 4mm×4mm×2mm, the size of the phase plate 7 is 4mm×4mm×2mm, and the size of the beam splitter 9 is 4mm×4mm×3mm.

[0033] More specifically: the gradient refractive index lens has 1NA (numerical aperture) = 0.5, f = 0.2 mm, a diameter of 2 mm, and a length of 10 mm.

[0034] More specifically: the self-focusing lens 1, annular aperture 2, hemispherical lens 3, monochromatic light source 4, memory 6, phase plate 7, tube lens 8 and beam splitter 9 are all integrated in the housing 5 of the miniaturized microscopic imaging system made of 3D-printed optical resin.

[0035] More specifically: the tube lens 8 has a focal length of f=6 mm and a diameter of D=5 mm, and is used to converge the differentiated light emitted by the sample onto the photosensitive surface of the storage 6 .

[0036] More specifically: the memory 6 has a pixel size of 6 μm and a field of view of up to 700×700 μm.

[0037] More specifically: the device has a total length of 20 mm, a width of 15 mm×15 mm, and a mass of only 3 g. It can be easily fixed on a multi-axis robotic arm to achieve lateral movement, axial movement, and coaxial rotation.

[0038] More specifically: the annular aperture 2 is constructed as an opaque flat black (light absorbing) plate with a transparent annular ring, which is located in the front focal plane (aperture) of the condenser, so that the sample can be illuminated by the defocused, parallel light wavefronts emitted from the ring. The microscope condenser images the annular aperture at infinity.

[0039] More specifically: the phase plate 7 comprises a ring etched in glass with reduced thickness to push the phase difference of the surround (S) wave to a quarter wavelength. Typically, the ring is also coated with a partially absorbing metal film to reduce the amplitude of the surround light by 60%-90%.

[0040] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted for facilitating understanding of the technical solution of the present invention, and are not used to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the core technical solution disclosed in the present invention, but the protection scope defined by the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens, characterized in that: It includes an illumination module, a phase amplitude conversion module, and a miniaturized imaging acquisition module; The lighting module comprises, in order of light propagation direction: a monochromatic light source (4), a hemispherical lens (3), an annular aperture (2), a beam splitter (9), a self-focusing lens (1), a beam splitter (9), a tube lens (8), a phase plate (7) and a memory (6); The phase amplitude conversion module comprises, in order according to the light propagation direction: an annular aperture (2), a beam splitter (9), a self-focusing lens (1), a beam splitter (9), a tube lens (8), and a phase plate (7); The miniaturized acquisition module comprises, in order according to the light propagation direction, a tube lens (8), a phase plate (7) and a memory (6).

2. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The monochromatic light source (4) is closely attached to the hemispherical lens (3), ensuring that the volume is compressed to the maximum extent possible while the light source is transformed from a spherical wave into parallel light.

3. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The size of the annular aperture (2) is 4 mm×4 mm×2 mm, the size of the phase plate (7) is 4 mm×4 mm×2 mm, and the size of the beam splitter (9) is 4 mm×4 mm×3 mm.

4. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The gradient refractive index lens (1) has a numerical aperture of 0.5 mm, f=0.2 mm, a diameter of 2 mm, and a length of 10 mm.

5. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The self-focusing lens (1), annular aperture (2), hemispherical lens (3), monochromatic light source (4), memory (6), phase plate (7), tube lens (8) and beam splitter (9) are all integrated in a housing (5) of a miniaturized microscopic imaging system made of 3D-printed optical resin.

6. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The tube lens (8) has a focal length f=6 mm and a diameter D=5 mm, and is used to converge the light emitted by the sample onto the photosensitive surface of the storage device (6).

7. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The memory (6) has a pixel size of 6 μm and a field of view of up to 700×700 μm.

8. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The device has a total length of 20 mm, a width of 15 mm×15 mm, and a mass of only 3 g. It can be easily fixed on a multi-axis robotic arm to achieve lateral movement, axial movement, and coaxial rotation.

9. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The annular diaphragm (2) is constructed as an opaque flat black (light absorbing) plate with a transparent annular ring, which is located in the front focal plane (aperture) of the condenser so that the sample can be illuminated by the defocused, parallel light wavefronts emitted from the ring. The microscope condenser images the annular aperture at infinity.

10. The miniaturized phase contrast microscopy imaging device based on a gradient refractive index lens according to claim 1, characterized in that: The phase plate (7) comprises a ring etched in glass with reduced thickness to push the phase difference of the surround (S) wave by a quarter wavelength. Typically, the ring is also coated with a partially absorbing metal film to reduce the amplitude of the surround light by 60%-90%.

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