A microscope device

Abstract

The application relates to the technical field of three-dimensional topography measurement, in particular to a microscopic device, which has a first measurement mode and a second measurement mode. In the first measurement mode, the first measurement mode can be combined by a first illumination module, a first objective lens and an image acquisition module, and the measurement of a measured object can be realized by adopting the interference mode of first detection light and first reference light in an imaging light path. In the second measurement mode, the second measurement mode can be combined by a second illumination module, a second objective lens and an image acquisition module, and the measurement of the measured object can be realized by adopting second illumination light with a predetermined coding pattern in the same imaging light path. Thus, different measurement modes can be adopted according to user requirements, the same image acquisition module and the same imaging light path can be used to meet different measurement requirements of the measured object, the microscopic device has multiple functions, and the cost of the microscopic device and the cost of various types of measurement are reduced.

Description

Technical Field

[0001] This application relates to the field of three-dimensional topography measurement technology, specifically to a microscopic device. Background Technology

[0002] The demand for 3D measurement technology has been growing rapidly in recent years. Because 3D measurement provides one dimension of information—depth—and depth itself is not very sensitive to factors such as pose and lighting, 3D measurement has a greater advantage for object recognition and measurement tasks.

[0003] Traditional 3D measurement microscopes have relatively limited functionality. High-precision microscopes have slow measurement speeds, while fast-speed microscopes have low precision. Different microscopes are suited to different measurement needs, requiring users to select different microscopes based on their specific requirements. This means users need to have multiple microscopes to meet various measurement needs, resulting in higher measurement costs. Utility Model Content

[0004] This application provides a microscopic device to solve the technical problem of high measurement costs for microscopic devices with limited functionality and multiple measurement needs.

[0005] According to one aspect of this application, one embodiment provides a microscope device having a first measurement mode and a second measurement mode, the microscope device comprising:

[0006] A first lighting module, used to generate a first lighting light.

[0007] The second illumination module includes a second light source and a structured light modulation component. The light emitted by the second light source is converted into a second illumination light with a predetermined coded pattern after passing through the structured light modulation component.

[0008] Objective lens module, the objective lens module including a first objective lens and a second objective lens;

[0009] In the first measurement mode, the first objective lens can be switched to move along the optical path of the first illumination light illuminating the object under test. The first illumination light passes through the first objective lens and illuminates the object under test and is reflected by the object under test. The first objective lens collects the light reflected by the object under test to form a first detection light transmitted along the imaging optical path. The first objective lens has a reference plate, which is configured to reflect the first illumination light to form a first reference light transmitted along the imaging optical path. The first reference light and the first detection light interfere with each other.

[0010] In the second measurement mode, the second objective lens can be switched to move into the optical path of the second illumination light illuminating the object under test. The second illumination light passes through the second objective lens and then illuminates the object under test and is reflected by the object under test. The second objective lens collects the light reflected by the object under test to form a second detection light transmitted along the imaging optical path.

[0011] An image acquisition module, located on the imaging optical path, is used to receive the interference image of the first reference light and the first detection light in the first measurement mode to obtain a first imaging image, or to receive the second detection light in the second measurement mode to obtain a second imaging image.

[0012] In an optional embodiment, the microscope device further includes a controller that controls the structured light modulation component to generate a first structured light or a second structured light according to user requirements. The second illumination light includes the first structured light or the second structured light, and the encoding pattern of the first structured light is different from the encoding pattern of the second structured light.

[0013] In one optional embodiment, the second illumination module includes a plurality of second light sources and a beam combiner group. The plurality of second light sources generate multiple illumination lights with different wavelengths. The beam combiner group is used to integrate the multiple illumination lights with different wavelengths into a fused light. The structured light modulation component receives the fused light to generate the second illumination light.

[0014] In one optional embodiment, the second illumination module includes a relay mirror group located on the light-emitting side of the structured light modulation component, the relay mirror group being used to modulate the second illumination light into an infinite yoke beam; the image acquisition module includes an imaging mirror group and a detector, the focal length of the imaging mirror group being equal to the focal length of the relay mirror group.

[0015] In one optional embodiment, the first illumination light is an infinite yoke beam, and the first illumination module includes a first light source, a first lens group, and a second lens group. The first lens group is used to converge the illumination light generated by the first light source, and the second lens group is used to integrate the illumination light converged by the first lens group into the first illumination light.

[0016] In an optional embodiment, the first illumination module further includes a first reflector located between the first lens group and the second lens group, with the first reflector positioned at the focal point of the first lens group to reflect the illumination light converged by the first lens group to the second lens group.

[0017] In an optional embodiment, the first illumination module and the second illumination module are located on the same side of the imaging optical path, and the microscopic device includes a first beam splitter and a second beam splitter. The first beam splitter is located at the intersection of the optical paths of the first illumination light and the second illumination light. The first beam splitter is used to reflect at least a portion of the first illumination light in the first measurement mode and transmit at least a portion of the second illumination light in the second measurement mode.

[0018] The second beam splitter is located in the imaging optical path and is used to reflect a portion of the first illumination light to the object under test in the first measurement mode, and to transmit the first reference light and the first detection light that generate interference to the image acquisition module; it is also used to reflect a portion of the second illumination light to the object under test in the second measurement mode, and to transmit the second detection light to the image acquisition module.

[0019] In one optional embodiment, the microscope device includes a notch filter module located on the light-emitting side of the second beam splitter. The notch filter module is used to absorb a portion of the first illumination light transmitted through the second beam splitter in the first measurement mode, and also to absorb a portion of the second illumination light transmitted through the second beam splitter in the second measurement mode.

[0020] In one optional embodiment, the first illumination module and the second illumination module are located on opposite sides of the imaging optical path. The microscopic device includes a first beam splitter and a second beam splitter. The first beam splitter is located at the intersection of the first illumination light and the imaging optical path, and is used to reflect a portion of the first illumination light to the object under test and transmit the first reference light and the first detection light that generate interference to the image acquisition module. The second beam splitter is located at the intersection of the second illumination light and the imaging optical path, and is used to reflect a portion of the second illumination light to the object under test and transmit the second detection light to the image acquisition module.

[0021] In one optional embodiment, the microscope device includes a first notch module and a second notch module. The first notch module is located on the light-emitting side of the first beam splitter and is used to absorb the portion of the first illumination light transmitted through the first beam splitter in the first measurement mode. The second notch module is located on the light-emitting side of the second beam splitter and is used to absorb the portion of the second illumination light transmitted through the second beam splitter in the second measurement mode.

[0022] The microscope device according to the above embodiments has a first measurement mode and a second measurement mode. In the first measurement mode, the measurement of the object under test is achieved by means of interference between the first detection light and the first reference light in the imaging optical path through the first illumination module, the first objective lens and the image acquisition module. In the second measurement mode, the measurement of the object under test is achieved by means of the second illumination module, the second objective lens and the image acquisition module, through the second illumination light with a predetermined coding pattern in the same imaging optical path. In this way, different measurement modes can be used according to user needs, through the same image acquisition module and the same imaging optical path, to meet different measurement needs of the object under test. This makes the microscope device multifunctional while reducing the cost of the microscope device and the cost of various types of measurements. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a microscope device according to one embodiment;

[0024] Figure 2 This is a schematic diagram of the optical structure of a microscopic device according to one embodiment;

[0025] Figure 3 This is a schematic diagram of the optical structure of a microscope device according to another embodiment;

[0026] Figure 4 This is a schematic diagram of a portion of the optical structure of a microscope device in a first measurement mode according to an embodiment. The second beam splitter and the object under test are omitted in the figure.

[0027] Figure 5 This is a schematic diagram of a portion of the optical structure of a microscope device in a second measurement mode according to one embodiment. The first beam splitter and the object under test are omitted in the figure.

[0028] In the picture:

[0029] 1. First illumination module; 11. First light source; 12. First lens group; 121. First biconvex positive lens; 122. First meniscus negative lens; 123. First cemented lens; 1231. Second meniscus negative lens; 1232. Second biconvex positive lens; 13. Second lens group; 131. Third meniscus negative lens; 132. Second cemented lens; 1321. Fourth meniscus negative lens; 1322. Third biconvex positive lens; 14. Aperture stop; 15. First reflecting mirror;

[0030] 2. Second illumination module; 21. Second light source; 22. Beam combiner lens group; 23. Compound eye microlens; 24. Fourier integrator lens; 25. Second reflecting mirror; 26. Transmission-reflection assembly; 27. Structured light modulation assembly; 28. Relay lens group;

[0031] 3. Objective lens module; 31. Objective lens switching stage; 32. First objective lens; 321. Reference plate; 322. Beam splitter; 33. Second objective lens;

[0032] 4. Image acquisition module; 41. Imaging lens group; 42. Detector;

[0033] 5. Controller; 60. First beam splitter; 61. Second beam splitter; 71. Notch filter module; 62. First beam splitter; 63. Second beam splitter; 72. First notch filter module; 73. Second notch filter module;

[0034] 8. The object being tested.

[0035] Explanation of reference numerals in parentheses in the accompanying drawings: The feature referred to by the reference numerals in parentheses in the accompanying drawings is the feature represented by both the number inside the parentheses and the number outside the parentheses. Detailed Implementation

[0036] The present application will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0037] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments, and the operational steps involved in each embodiment can also be rearranged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for clearly describing a particular embodiment and do not imply that they represent the necessary components and / or order.

[0038] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0039] This application discloses a microscopic device for measuring the three-dimensional morphology of an object. The microscopic device of this application integrates multiple measurement modes and can selectively measure the three-dimensional morphology of the object according to the detection requirements of the object. It can reduce the cost of the microscopic device and the cost of multiple measurements while meeting different measurement requirements.

[0040] Please refer to Figures 1 to 5 The microscopic device in this embodiment includes a first illumination module 1, a second illumination module 2, an objective lens module 3, and an image acquisition module 4. The first illumination module 1 generates a first illumination light. The second illumination module 2 includes a second light source 21 and a structured light modulation component 27. The light emitted by the second light source 21 passes through the structured light modulation component 27 to form a second illumination light with a predetermined coded pattern. The microscopic device has a first measurement mode and a second measurement mode. In the first measurement mode, only the first illumination light generated by the first illumination module 1 participates in the detection of the object under test 8, and the second illumination module 2 does not participate in the detection of the object under test 8. In the second measurement mode, only the second illumination light generated by the second illumination module 2 participates in the detection of the object under test 8, and the first illumination module 1 does not participate in the detection of the object under test 8.

[0041] The objective module 3 includes an objective switching stage 31, a first objective lens 32, and a second objective lens 33. Both the first objective lens 32 and the second objective lens 33 are mounted on the objective switching stage 31. By moving the objective switching stage 31, the first objective lens 32 can be switched to the measurement optical path of the object under test 8 in the first measurement mode, so that the second objective lens 33 does not participate in the measurement of the object under test 8. Alternatively, by moving the objective switching stage 31, the second objective lens 33 can be switched to the measurement optical path of the object under test 8 in the second measurement mode, so that the first objective lens 32 does not participate in the measurement of the object under test 8.

[0042] Specifically, in the actual measurement process, in the first measurement mode, the first illumination module 1 generates a first illumination light, and the first objective lens 32 is switched and moved to the optical path of the first illumination light illuminating the object under test 8. The first illumination light passes through the first objective lens 32 and then illuminates the object under test 8 and is reflected by the object under test 8. The first objective lens 32 collects the light reflected by the object under test 8 to form a first detection light transmitted along the imaging optical path. The first objective lens 32 has a reference plate 321, which is configured to reflect the first illumination light to form a first reference light transmitted along the imaging optical path. The first reference light and the first detection light can interfere in the imaging optical path.

[0043] The objective lens also has a beam splitter 322, which has a certain beam splitting ratio, such as 1:1 or other ratios. The beam splitter 322 is located between the reference plate 321 and the object under test 8. The first illumination light entering the first objective lens 32 includes two parts. One part passes through the beam splitter 322 and illuminates the object under test 8 and is reflected by the object under test 8. The first objective lens 32 collects the light reflected by the object under test 8 and makes it pass through the beam splitter 322 to form the first detection light transmitted along the imaging optical path. The other part is reflected at the beam splitter 322 to the reference plate 321, reflected by the reference plate 321 to the beam splitter 322, and then reflected by the beam splitter 322 to form the first reference light transmitted along the imaging optical path. The first reference light and the first detection light have a certain optical path difference, and the two beams will interfere in the imaging optical path.

[0044] In the second measurement mode, the second illumination module 2 generates a second illumination light, and the second objective lens 33 is switched and moved to the optical path of the second illumination light illuminating the object under test 8. After passing through the second objective lens 33, the second illumination light illuminates the object under test 8 and is reflected by the object under test 8. The second objective lens 33 collects the light reflected by the object under test 8 to form a second detection light transmitted along the imaging optical path.

[0045] The image acquisition module 4 is located on the imaging optical path. The image acquisition module 4 includes an imaging lens group 41 and a detector 42. The imaging lens group 41 is positioned between the detector 42 and the objective lens module 3 on the imaging optical path. In the first measurement mode, the first objective lens 32 is switched to the imaging optical path, and the imaging lens group 41 can receive the first reference light and the first detection light emitted from the first objective lens 32. The detector 42 can acquire the first imaging image based on the interference image of the first reference light and the first detection light. In the second measurement mode, the second objective lens 33 is switched to the imaging optical path, and the imaging lens group 41 can receive the second detection light emitted from the second objective lens 33. The detector 42 can acquire the second imaging image based on the second detection light. Thus, the first and second measurement modes share the same imaging optical path and the same image acquisition module 4. Depending on the measurement requirements of the object 8, the measurement of the object 8 can be selectively achieved through either the first or second measurement mode, making the microscope multifunctional while reducing the cost of the microscope and multifunctional measurement.

[0046] In some embodiments, the first measurement mode includes a white light interferometry measurement mode, wherein the first illumination light is white light. Since white light has a large spectral bandwidth but a short coherence, the luminous intensity corresponding to different wavelengths of light is different. Only when the optical path difference between the first reference light and the first detection light is very small can the two beams of light interfere. When the optical path difference is zero, the first reference light and the first detection light produce high-contrast interference fringes, which can accurately locate the surface height of the object under test 8. During the measurement process, the interference fringes of different height surfaces of the object under test 8 can be captured by vertical scanning to construct the true three-dimensional shape of the object under test 8, thereby improving the accuracy and precision of the three-dimensional shape measurement of the object under test 8.

[0047] In some embodiments, please refer to Figures 2 to 4 The first lighting module 1 is a Kohler lighting module, which includes a first light source 11, a first lens group 12 and a second lens group 13. The first light source 11 is used to generate illumination light, which is white light. The first lens group 12 is used to converge the illumination light generated by the first light source 11. The second lens group 13 is used to integrate the illumination light converged by the first lens group 12 into a first illumination light, which is an infinite yoke beam.

[0048] The first lens group 12 and the second lens group 13 are arranged sequentially in the illumination light transmission direction. The first lens group 12 includes a first biconvex positive lens 121, a first meniscus negative lens 122 and a first cemented lens 123 arranged sequentially in the illumination light transmission direction. The first cemented lens 123 is formed by cementing the second meniscus negative lens 1231 and the second biconvex positive lens 1232 together. Both the first biconvex positive lens 121 and the first cemented lens 123 are used to converge the illumination light generated by the first light source 11. The second lens group 13 includes a third meniscus negative lens 131 and a second cemented lens 132 arranged sequentially in the illumination light transmission direction. The second cemented lens 132 is formed by cementing the fourth meniscus negative lens 1321 and the third biconvex positive lens 1322 together. The second cemented lens 132 is used to integrate the illumination light passing through the third meniscus negative lens 131 into the first illumination light.

[0049] The first illumination module 1 also includes an aperture stop 14, which is located between the first meniscus negative lens 122 and the first cemented lens 123 in the direction of illumination light transmission. It is used to limit the aperture angle of the illumination light, adjust the energy distribution of the illumination light, and improve the uniformity of illumination.

[0050] In some embodiments, please refer to Figure 3 and Figure 4To reduce the size of the first illumination module 1 and facilitate its placement in the microscope apparatus, the first illumination module 1 further includes a first reflector 15. This first reflector 15 is located between the first lens group 12 and the second lens group 13 in the illumination light transmission direction, and is situated at the focal point of the second cemented lens 132 or the entire first lens group 12. The incident angle of the illumination light on the first reflector 15 can be 45° to ensure the illumination light transmission path forms a 90° bend, thereby reducing the overall size of the first illumination module 1 in the incident light transmission direction of the first reflector 15. Alternatively, if there is sufficient installation space in the microscope apparatus, the first reflector 15 can be omitted from the first illumination module 1, and the focal point of the first cemented lens 123 can be located between the first cemented lens 123 and the third meniscus negative lens 131 to achieve illumination light transmission.

[0051] In addition to the Kohler illumination module, in other embodiments, the first illumination module 1 may include other lens group structures that integrate white light sources to form an infinitely conjugate beam, besides the first light source 11. In this application, the first illumination module 1 preferably has the structure of a Kohler illumination module, wherein the emitting surface of the first light source 11 has a certain extended dimension and cannot be considered an ideal point light source. This extended dimension can be used to match the composite focal length of the Kohler illumination module, thereby forming a collimated beam with a certain field of view in the image space. This beam is then matched with the first objective lens 32 to form conjugate illumination on the surface of the object 8 being measured, thus improving the imaging quality and measurement accuracy in the first measurement mode.

[0052] In some embodiments, the second lighting module 2 includes a second light source 21. There may be only one second light source 21, which may be a monochromatic LED light source that produces monochromatic light, such as red light, white light, blue light, or violet light.

[0053] In some embodiments, please refer to Figure 2 , Figure 3 and Figure 5 The second illumination module 2 has multiple second light sources 21, each of which is a monochromatic LED light source. Different second light sources 21 produce different wavelengths of illumination light. For example, there can be two second light sources 21, which can produce red light and blue light respectively, or there can be three second light sources 21, which can produce red light, blue light and green light respectively. The second illumination module 2 also includes a beam combiner group 22, which is used to integrate the light of different wavelengths produced by multiple second light sources 21 into a fused light that illuminates the structured light modulation component 27. After receiving the fused light, the structured light modulation component 27 can generate a second illumination light with a predetermined coded pattern.

[0054] The beam combiner assembly 22 includes a beam splitter, which can be a dichroic mirror or a semi-transparent mirror. In a preferred embodiment, a dichroic mirror is selected as the beam splitter to improve the utilization efficiency of the illumination light. In embodiments where there are three second light sources 21, the dichroic mirror transmits or reflects the illumination light generated by one of the second light sources 21 to fuse three different wavelengths of illumination light into a single beam. There can be two beam splitters, i.e., two dichroic mirrors. One dichroic mirror can transmit red and blue light and reflect green light, while the other reflects red light and transmits blue and green light; or one can transmit red light and reflect green light, while the other reflects blue light and transmits red and green light; or one can transmit green light and reflect red light, while the other reflects blue light and transmits red and green light.

[0055] In embodiments where the number of second light sources 21 is greater than three, the fusion of multiple illumination lights of different colors and wavelengths can be achieved by increasing the number of dichroic mirrors and combining the reflection and transmission characteristics of multiple dichroic mirrors.

[0056] In the above embodiment, the structure that fuses multiple illumination lights of different colors and wavelengths through the beam combiner group 22 can selectively turn on or off each of the second light sources 21 so that illumination lights of different colors can participate in the measurement of the object under test 8 in the second illumination module 2. This can meet the various measurement needs of the object under test 8 and make the microscopic device multifunctional.

[0057] In some embodiments, please continue to refer to Figure 2 , Figure 3 and Figure 5 The fused light obtained by the beam combiner group 22 is broadband light. This broadband light can be processed by the compound eye differential lens 23 and at least two Fourier integrator lenses 24 to form a uniform beam. The compound eye differential lens 23 can differentiate the broadband light to form multiple sub-beams. The at least two Fourier integrator lenses 24 can converge the multiple sub-beams output by the compound eye differential lens 23. It is difficult to achieve the integration effect of a single Fourier integrator lens 24 on multiple beams. Using two or more Fourier integrator lenses 24 can converge the multiple sub-beams to the same illumination area through multiple convergences. On the one hand, it makes the light spot of the output beam more uniform, and on the other hand, it can reduce the optical performance requirements of a single Fourier integrator lens 24. Of course, in other embodiments, the broadband light can also be homogenized by a combination of a light homogenizing rod or other optical elements.

[0058] In some embodiments, please continue to refer to Figure 2 , Figure 3 and Figure 5The second illumination module 2 also includes a second reflector 25, which is used to deflect the light path, making the light path layout in the second illumination module 2 more compact and reasonable. The second reflector 25 can be placed between two Fourier integrating lenses 24, so that the two Fourier integrating lenses 24 are set at a right angle, which can reduce the space occupied by the second illumination module 2. Of course, in embodiments where there is sufficient installation space in the microscope device, the second reflector 25 can be omitted.

[0059] In some embodiments, reference continues to be made to Figure 2 , Figure 3 and Figure 5 The second illumination module 2 also includes a transmission-reflection component 26, which is located between two Fourier integrator lenses 24 and the structured light modulation component 27. The illumination light output by the two Fourier integrator lenses 24 is reflected or refracted by the transmission-reflection component 26, so that the illumination light shines on the structured light modulation component 27 at a preset incident angle. If the second reflector 25 is used in conjunction with the transmission-reflection component 26, the incident angle of the light beam on the transmission-reflection component 26 can be adjusted, thereby adjusting the exit angle of the light beam on the transmission-reflection component 26, and finally shining on the structured light modulation component 27 at a preset incident angle.

[0060] The transmission-reflection assembly 26 may include one or more prisms and mirrors, which irradiate the illumination light output by the two Fourier integrator lenses 24 onto the structured light modulation assembly 27 at a preset incident angle by means of refraction or reflection, and transmit the structured light with a predetermined coding pattern output by the structured light modulation assembly 27 to the object under test 8 by reflection.

[0061] In some embodiments, the structured light modulation component 27 includes a digital micromirror device, or may also include a reflective liquid crystal element, a spatial light modulator, and a grating. After receiving illumination light, the structured light modulation component 27 can generate a second illumination light with a predetermined coded pattern. The structured light modulation component 27 enables the second illumination module 2 to cooperate with the image acquisition module 4, allowing for wide-area measurement of the three-dimensional morphology of the object under test 8 in the second measurement mode. This helps to shorten the measurement time of the three-dimensional morphology of the object under test 8 and improve measurement efficiency.

[0062] In some embodiments, please refer to Figure 2 , Figure 3 and Figure 5The second illumination module 2 also includes a relay mirror group 28, which is located on the light-emitting side of the structured light modulation component 27. The relay mirror group 28 is composed of multiple optical elements and is used to receive the second illumination light. It modulates the second illumination light into an infinitely conjugate beam by converging or diverging the second illumination light. The focal length of the relay mirror group 28 is equal to the focal length of the imaging mirror group 41 in the image acquisition module 4, so that the relay mirror group 28 can be smoothly connected to the infinitely conjugate second objective lens 33. This makes the pixels of the digital micromirror device, the surface of the measured object 8, and the surface of the detector 42 conjugate, and the pixels of the digital micromirror device and the detector 42 correspond one-to-one, which helps to improve the measurement accuracy in the second measurement mode.

[0063] The second measurement mode includes a wide-swath confocal measurement mode. Traditional confocal microscopy is a single-point confocal microscopy, which is based on the principle of point conjugation. It consists of three conjugated points: a point light source, the measured point, and a pinhole at the probe end. The point light source is focused by the objective lens onto the surface of the measured object to form point illumination. The reflected light from this point re-enters the objective lens and is imaged through the tube lens. The pinhole at the probe end is used to filter out the measured object information before and after focus, allowing only the measured object information on the focal plane to pass through. Because single-point confocal microscopy can only measure a very small area of ​​the object each time, the measurement time is long when the measured object is large, and nonlinear measurement errors caused by moving parts are introduced.

[0064] In the second measurement mode of this application, a structured light modulation component 27 is introduced, which uses a second illumination light with a predetermined coding pattern to replace the point light source in the traditional confocal method, realizing wide-range multi-point confocal measurement, so that each measurement is changed from a point to a surface, the single measurement range is expanded, the measurement time is greatly shortened, and the error of nonlinear measurement is reduced.

[0065] In some embodiments, the second measurement mode also includes an active illumination multifocal plane stacking measurement mode. Traditional multifocal plane stacking measurement mainly utilizes the shallow depth of field of the objective lens under bright field illumination conditions. By moving the focal plane of the objective lens, multiple sets of images with different focal planes are captured. By identifying the best sharp plane, a three-dimensional image is stitched together. This measurement technique heavily relies on the depth of field of the microscope objective lens and the strength of the algorithm, resulting in low measurement accuracy. Furthermore, images of different focal planes are affected by aberrations, and fusing images of smooth, lenticular, or textureless surfaces can produce artifacts.

[0066] The active illumination multifocal surface superposition measurement mode of this application mainly solves the problem of the failure of traditional multifocal surface superposition in dealing with smooth, transparent, and textureless surfaces in microscopic three-dimensional reconstruction. In the active illumination multifocal surface superposition measurement mode, the active structured light illumination scheme generated by the structured light modulation component 27 projects the predetermined coded pattern, such as stripes, grids, etc., onto the object surface through the micro-projection array, thereby creating texture information on the object surface to achieve the reconstruction of textureless surfaces.

[0067] The active illumination multifocal plane superposition measurement mode and the wide-swath confocal measurement mode share the second illumination module 2, the second objective lens 33, and the image acquisition module 4. The difference is that the encoding pattern of the second illumination light generated by the structured light modulation component 27 in the active illumination multifocal plane superposition measurement mode is different from that in the wide-swath confocal measurement mode.

[0068] To enable the measurement of the three-dimensional morphology of the object under test 8 through an active illumination multifocal plane superposition measurement mode in the second measurement mode, a microscopic device is provided, including a controller 5. The controller 5 is electrically connected to the structured light modulation component 27, and is also electrically connected to multiple second light sources 21. The controller 5 can control the structured light modulation component 27 to generate a first structured light or a second structured light according to user needs. The second illumination light includes the first structured light or the second structured light. The encoding pattern of the first structured light and the encoding pattern of the second structured light are different. The first structured light generated by the structured light modulation component 27 participates in the wide-range confocal measurement of the surface morphology of the object under test 8, which has high measurement accuracy. The second structured light generated by the structured light modulation component 27 participates in the active illumination multifocal plane superposition measurement of the surface morphology of the object under test 8, which has a faster measurement speed.

[0069] Of course, the preset coding pattern of the first structured light and the preset coding pattern of the second structured light are not limited to one pattern. The difference between the coding pattern of the first structured light and the coding pattern of the second structured light is that the smallest unit of the coding pattern of the first structured light is a single micromirror unit in the digital micromirror device, and the coding pattern of the first structured light is composed of multiple dispersed micromirror units; the smallest unit of the coding pattern of the second structured light is a stripe composed of multiple continuous micromirror units in the digital micromirror device, and the coding pattern of the second structured light is composed of multiple stripes arranged at intervals or in an alternating manner.

[0070] In other embodiments, while meeting the measurement requirements, the second measurement mode may also be limited to one of the active illumination multifocal plane superposition measurement mode and the wide-range confocal measurement mode, so that the controller 5 can only control the structured light modulation component 27 to generate one of the first structured light and the second structured light.

[0071] In some embodiments, the white light interferometry in the first measurement mode and the active illumination multifocal plane superposition measurement and wide-swath confocal measurement in the second measurement mode share the same imaging optical path and image acquisition module 4. Please refer to Figure 2The first illumination module 1 and the second illumination module 2 are located on the same side of the imaging optical path. The microscope device includes a first beam splitter 60 and a second beam splitter 61. The first beam splitter 60 is located at the intersection of the optical paths of the first illumination light generated by the first illumination module 1 and the second illumination light generated by the second illumination module 2. The first beam splitter 60 has a certain beam splitting ratio. For example, the first beam splitter 60 can be a semi-transparent and semi-reflective mirror. The ratio of transmitted light to reflected light of the first beam splitter 60 can be 1:1, or it can be 2:1 or other ratios. The first beam splitter 60 can reflect a certain proportion of the first illumination light and transmit the remaining first illumination light in the first measurement mode. The first beam splitter 60 can also transmit a certain proportion of the second illumination light and reflect the remaining second illumination light in the second measurement mode. For the first beam splitter 60, the angle between the incident first illumination light and the incident second illumination light is 90° to satisfy the shared optical path of the reflected part of the first illumination light and the transmitted part of the second illumination light.

[0072] The second beam splitter 61 is located in the imaging optical path and between the objective lens module 3 and the image acquisition module 4. The first illumination light in the first measurement mode and the second illumination light in the second measurement mode both need to be transmitted to the corresponding first objective lens 32 and second objective lens 33 through the second beam splitter 61. The second beam splitter 61 has a certain beam splitting ratio, such as the ratio of transmitted light to reflected light of the second beam splitter 61 being 1:1, or 2:1 or other ratios. The second beam splitter 61 can reflect a certain proportion of the first illumination light to the first objective lens 32 in the first measurement mode, and the remaining first illumination light is transmitted by the second beam splitter 61 as stray light. The second beam splitter 61 can reflect a certain proportion of the second illumination light to the second objective lens 33 in the second measurement mode, and the remaining second illumination light is transmitted by the second beam splitter 61 as stray light.

[0073] Since the second beam splitter 61 is located in the imaging optical path, the first detection light, the first reference light, and the second detection light transmitted along the imaging optical path are all received by the second beam splitter 61 after exiting from the objective lens module 3. The second beam splitter 61 can transmit a certain proportion of the first detection light and a certain proportion of the first reference light to the image acquisition module 4 in the first measurement mode, and the remaining first detection light and the first reference light are reflected by the second beam splitter 61 as stray light. The second beam splitter 61 can also transmit a certain proportion of the second detection light in the second measurement mode, and the remaining second detection light is reflected by the second beam splitter 61 as stray light.

[0074] In some embodiments, please continue to refer to Figure 2To reduce stray light interference with imaging, the microscopic apparatus includes a notch filter module 71. This notch filter module 71 can be a structure with a small aperture capable of absorbing stray light. Two notch filter modules 71 are provided. One is located on the light-emitting side of the second beam splitter 61, used to absorb stray light formed by the first illumination light or the second illumination light. The other notch filter module 71 is located on the light-emitting side of the first beam splitter 60, arranged opposite to the first illumination module 1 on the opposite side of the first beam splitter 60. It can absorb stray light in both the first measurement mode and the second measurement mode. Specifically, in the first measurement mode, it absorbs a portion of the first illumination light transmitted by the first beam splitter 60, and in the second measurement mode, it absorbs a portion of the second illumination light reflected by the first beam splitter 60. This prevents the stray light from affecting the transmission of the first and second illumination lights in the illumination optical path and from affecting the acquisition of the imaging image.

[0075] Other structures can also be used to enable the first and second measurement modes to share the image acquisition module 4 and the imaging optical path. For example, please refer to some embodiments. Figure 3 The first illumination module 1 and the second illumination module 2 are located on opposite sides of the imaging optical path. The microscopic device includes a first beam splitter 62 and a second beam splitter 63. Both the first beam splitter 62 and the second beam splitter 63 have a certain beam splitting ratio. Both the first beam splitter 62 and the second beam splitter 63 can be semi-transparent and semi-reflective mirrors. The first beam splitter 62 is located at the intersection of the first illumination light and the imaging optical path. The first beam splitter 62 can reflect a portion of the first illumination light to the object under test 8 in the first measurement mode, and transmit a portion of the first reference light and the first detection light that generate interference to the image acquisition module. In addition to block 4, the first beam splitter 62 can also transmit the remaining part of the first illumination light to form stray light and reflect the remaining part of the first reference light and the first detection light that cause interference; the second beam splitter 63 is located at the intersection of the second illumination light and the imaging light path. The second beam splitter 63 can reflect part of the second illumination light to the object under test 8 in the second measurement mode and transmit part of the second detection light to the image acquisition module 4. In addition, the second beam splitter 63 can also transmit the remaining part of the second illumination light to form stray light and reflect the remaining part of the second detection light.

[0076] Furthermore, since both the first beam splitter 62 and the second beam splitter 63 are located on the imaging optical path, the first beam splitter 62 can also transmit the second detection light to the image acquisition module 4 in the second measurement mode, and the second beam splitter 63 can transmit the first reference light and the first detection light that generate interference to the image acquisition module 4 in the first measurement mode.

[0077] Further, please refer to Figure 3To reduce stray light interference with imaging, the microscope setup includes a first notch module 72 and a second notch module 73. The first notch module 72 is located on the light-emitting side of the first beam splitter 62, and is located on opposite sides of the first illumination module 1. The first notch module 72 is used to absorb stray light transmitted through the first beam splitter 62 in the first measurement mode, that is, to absorb the remaining portion of the first illumination light transmitted through the first beam splitter 62, so as to avoid this stray light affecting the acquisition of the first imaging image. The second notch module 73 is located on the light-emitting side of the second beam splitter 63, and is located on opposite sides of the second illumination module 2. The second notch module 73 is used to absorb stray light transmitted through the second beam splitter 63 in the second measurement mode, that is, to absorb the remaining portion of the second illumination light transmitted through the second beam splitter 63, so as to avoid this stray light affecting the acquisition of the second imaging image.

[0078] In some embodiments, the notch filter module in the microscope device may be omitted when the requirements for imaging quality and measurement accuracy are not high.

[0079] In some embodiments, the microscopic device may have at least three measurement modes: a first measurement mode, namely a white light interferometry measurement mode; a wide-area confocal measurement mode within the second measurement mode; and an active illumination multifocal plane superposition measurement mode within the second measurement mode. Specifically, the controller 5 can control the first light source 11 or the second light source 21 to turn on, thereby switching between the first and second measurement modes. When the second light source 21 is on, the controller 5 can also control the structured light modulation component 27 to generate first or second structured light, thereby switching between the wide-area confocal measurement mode and the active illumination multifocal plane superposition measurement mode. In addition, the controller 5 can also control a portion of the illumination light from the second light source 21 to participate in the measurement of the three-dimensional morphology of the object under test 8, thereby increasing the measurement modes of the microscopic device, realizing multi-functional measurement of the microscopic device, and reducing the measurement cost in multiple modes.

[0080] During white light interferometry, the controller 5 controls the first light source 11 to turn on, and controls the stage of the microscope (not shown in the figure) to perform coarse adjustment along the Z-axis, enabling the microscope to quickly perform its first focusing. Then, it scans the object 8 within a vertical range: First, it controls the piezoelectric device (not shown in the figure) of the microscope to move along the optical axis of the imaging optical path, i.e., along the Z-axis, within its reliable travel range, carrying the objective lens module 3. The image acquisition module then acquires interferometric images at different heights within this range. Subsequently, the stage performs a large-range coarse adjustment along the Z-axis and moves to a designated position, controlling the piezoelectric device to move within its reliable travel range to acquire interferometric images at different heights within this range. Interference images are obtained by repeatedly moving the stage along the Z-axis and moving the piezoelectric device within its stroke range. This allows points at different heights on the surface of the object under test (8) to be sequentially controlled to have zero optical path difference with the reference plate 321, generating interference. A series of interference images within the vertical range are acquired by the imaging lens group 41, converted into digital signals by the detector 42, and stored in the computer. Then, the stage is controlled to move in the XY plane, repeatedly acquiring interference images at different heights within different measurement fields of view until the object under test (8) is completely scanned. Finally, the computer analyzes and processes the digital signals to extract the positions of feature points and obtain the relative height of each pixel, thus realizing the measurement of the three-dimensional shape of the object under test (8).

[0081] The wide-field confocal measurement process and the active illumination multifocal plane measurement process are similar to the white light interferometry process. By moving the worktable and piezoelectric devices, imaging images at different heights are collected in different measurement fields of view in the XY plane. The images are converted into digital signals by the detector 42, and the relative height of each pixel is obtained by computer processing of the digital signals, thereby realizing the measurement of the three-dimensional shape of the object 8.

[0082] The difference is that in the wide-range confocal measurement process and the active illumination multifocal plane measurement process, the second light source 21 and the structured light modulation component 27 are both in the on state, while the first light source 11 is in the off state. The structured light modulation component 27 generates the first structured light in the wide-range confocal measurement process and the second structured light in the active illumination multifocal plane measurement process.

[0083] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A microscope device, characterized in that, The microscope device has a first measurement mode and a second measurement mode, and the microscope device includes: A first lighting module, used to generate a first lighting light. The second illumination module includes a second light source and a structured light modulation component. The light emitted by the second light source is converted into a second illumination light with a predetermined coded pattern after passing through the structured light modulation component. Objective lens module, the objective lens module including a first objective lens and a second objective lens; In the first measurement mode, the first objective lens can be switched to move along the optical path of the first illumination light illuminating the object under test. The first illumination light passes through the first objective lens and illuminates the object under test and is reflected by the object under test. The first objective lens collects the light reflected by the object under test to form a first detection light transmitted along the imaging optical path. The first objective lens has a reference plate, which is configured to reflect the first illumination light to form a first reference light transmitted along the imaging optical path. The first reference light and the first detection light interfere with each other. In the second measurement mode, the second objective lens can be switched to move into the optical path of the second illumination light illuminating the object under test. The second illumination light passes through the second objective lens and then illuminates the object under test and is reflected by the object under test. The second objective lens collects the light reflected by the object under test to form a second detection light transmitted along the imaging optical path. An image acquisition module, located on the imaging optical path, is used to receive the interference image of the first reference light and the first detection light in the first measurement mode to obtain a first imaging image, or to receive the second detection light in the second measurement mode to obtain a second imaging image.

2. The microscope device as claimed in claim 1, characterized in that, The microscopic device also includes a controller, which controls the structured light modulation component to generate a first structured light or a second structured light according to user needs. The second illumination light includes the first structured light or the second structured light, and the encoding pattern of the first structured light is different from that of the second structured light.

3. The microscope device as described in claim 1, characterized in that, The second illumination module includes multiple second light sources and a beam combiner. The multiple second light sources generate multiple illumination lights with different wavelengths. The beam combiner is used to integrate multiple illumination lights of different wavelengths into a fused light. The structured light modulation component receives the fused light to generate the second illumination light.

4. The microscope device as claimed in claim 1, characterized in that, The second illumination module includes a relay mirror group located on the light-emitting side of the structured light modulation component. The relay mirror group is used to modulate the second illumination light into an infinite yoke beam. The image acquisition module includes an imaging mirror group and a detector. The focal length of the imaging mirror group is equal to the focal length of the relay mirror group.

5. The microscope device as claimed in claim 1, characterized in that, The first illumination light is an infinite yoke beam. The first illumination module includes a first light source, a first lens group, and a second lens group. The first lens group is used to converge the illumination light generated by the first light source, and the second lens group is used to integrate the illumination light converged by the first lens group into the first illumination light.

6. The microscope apparatus as claimed in claim 5, characterized in that, The first illumination module further includes a first reflector, which is located between the first lens group and the second lens group. The first reflector is located at the focal point of the first lens group to reflect the illumination light converged by the first lens group to the second lens group.

7. The microscope apparatus as claimed in any one of claims 1 to 6, characterized in that, The first illumination module and the second illumination module are located on the same side of the imaging optical path. The microscopic device includes a first beam splitter and a second beam splitter. The first beam splitter is located at the intersection of the optical paths of the first illumination light and the second illumination light. The first beam splitter is used to reflect at least a portion of the first illumination light in the first measurement mode and transmit at least a portion of the second illumination light in the second measurement mode. The second beam splitter is located in the imaging optical path and is used to reflect a portion of the first illumination light to the object under test in the first measurement mode, and to transmit the first reference light and the first detection light that generate interference to the image acquisition module. It is also used to reflect a portion of the second illumination light to the object being measured in the second measurement mode, and to transmit the second detection light to the image acquisition module.

8. The microscope apparatus as claimed in claim 7, characterized in that, The microscope device includes a notch filter module located on the light-emitting side of the second beam splitter. The notch filter module is used to absorb the portion of the first illumination light transmitted through the second beam splitter in the first measurement mode, and also to absorb the portion of the second illumination light transmitted through the second beam splitter in the second measurement mode.

9. The microscope apparatus as claimed in any one of claims 1 to 6, characterized in that, The first illumination module and the second illumination module are located on opposite sides of the imaging optical path. The microscopic device includes a first beam splitter and a second beam splitter. The first beam splitter is located at the intersection of the first illumination light and the imaging optical path, and is used to reflect a portion of the first illumination light to the object under test, and transmit the first reference light and the first detection light that generate interference to the image acquisition module. The second beam splitter is located at the intersection of the second illumination light and the imaging optical path, and is used to reflect a portion of the second illumination light to the object under test, and transmit the second detection light to the image acquisition module.

10. The microscope device as claimed in claim 9, characterized in that, The microscopic device includes a first notch module and a second notch module. The first notch module is located on the light-emitting side of the first beam splitter and is used to absorb the portion of the first illumination light transmitted through the first beam splitter in the first measurement mode. The second notch module is located on the light-emitting side of the second beam splitter and is used to absorb the portion of the second illumination light transmitted through the second beam splitter in the second measurement mode.

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