An optical detection system

Abstract

The embodiment of the present application provides an optical detection system for improving the accuracy of obtaining the intensity of illumination light in an illumination light beam. The method of the embodiment of the present application comprises: an illumination optical system for emitting an illumination light beam and irradiating the illumination light beam to a detection object; a focusing optical system comprising a detection light emitting device and an adjusting device, wherein the detection light emitting device is used for emitting a detection light beam to the detection object to obtain the distance between the detection object and an imaging device through the detection light beam, and the adjusting device is used for adjusting the distance so that the detection object is located at the focal point of the imaging device, wherein the detection light beam and the illumination light beam are coupled through a coupler before being irradiated to the detection object; an illumination light intensity detection device for detecting the energy of the coupled illumination light beam; and an imaging device for imaging the focused detection object to obtain an image of the detection object, wherein the image of the detection object is used for feature detection.

Description

Technical Field

[0001] This invention relates to the field of optical inspection technology, and more particularly to an optical inspection system. Background Technology

[0002] In semiconductor wafer inspection systems, there are various illumination optical systems, such as illumination sources and autofocus sources. The illumination source provides an illumination beam to illuminate the object being inspected, while the autofocus source provides a focusing beam for automatic distance measurement. The brightness of the illumination beam on the surface of the object being inspected is a key indicator that needs to be monitored in real time. However, when monitoring the brightness of the illumination source in real time, it is also necessary to avoid interference from the autofocus source.

[0003] Existing technologies calculate the brightness of an illumination beam by using the grayscale of the final acquired image. However, image grayscale is affected not only by the intensity of the illumination light but also by camera parameters and the wavelength of the illumination. Therefore, the method of calculating the intensity of the illumination beam by using image grayscale is not very accurate. Summary of the Invention

[0004] This invention provides an optical detection system that can directly measure the intensity of a coupled illumination beam using an illumination intensity detection device, thereby improving the accuracy of obtaining the illumination intensity in the illumination beam.

[0005] This application provides an optical detection system, including: an illumination optical system, a focusing optical system, a coupler, an illumination intensity detection device, and an imaging device, wherein:

[0006] The illumination optical system is used to emit an illumination beam and illuminate the object being detected.

[0007] The focusing optical system includes a detection light emitting device and an adjustment device. The detection light emitting device is used to emit a focusing beam toward the detection object to obtain the distance between the detection object and the imaging device through the focusing beam. The adjustment device is used to adjust the distance so that the detection object is located at the focal point of the imaging device. The focusing beam and the illumination beam are coupled through the coupler before illuminating the detection object.

[0008] The illumination intensity detection device is used to detect the energy of the coupled illumination beam;

[0009] The imaging device is used to image the focused detection object to obtain an image of the detection object, wherein the image of the detection object is used for feature detection.

[0010] As one possible embodiment, the illumination intensity detection device and the illumination optical system are arranged coaxially along the direction of the illumination beam.

[0011] As one possible embodiment, the illumination intensity detection device includes a first optical component, a photodetector, and a signal processing unit, wherein:

[0012] The first optical component is used to receive the illumination beam from the coupled beam and isolate the focusing beam;

[0013] The photodetector is used to convert the light signal of the illumination beam after passing through the first optical component into an electrical signal.

[0014] The signal processing unit is used to measure the energy of the illumination beam based on the electrical signal.

[0015] As one possible embodiment, the illumination intensity detection device further includes a second optical component, wherein:

[0016] The second optical component is disposed in the optical path between the first optical component and the photodetector, and is used to focus the illumination beam passing through the first optical component onto the photodetector.

[0017] As one possible embodiment, the illumination intensity detection device further includes a third optical component, wherein:

[0018] The third optical component is used to attenuate the energy of the illumination beam passing through the second optical component to the energy detection range of the photodetector.

[0019] As one possible embodiment, the first optical component includes at least one of a bandpass filter, a high-pass filter, and a low-pass filter; the second optical component includes a lens group; and the third optical component includes an optical attenuator.

[0020] As one possible embodiment, the second optical component is perpendicular to the illumination beam after passing through the first optical component.

[0021] As one possible embodiment, at least one component of the first optical component, the third optical component, and the photodetector is tilted relative to the second optical component.

[0022] As one possible embodiment, the coupler includes a dichroic mirror for transmitting the focusing beam to the object being detected, transmitting a beam with a first energy ratio in the illumination beam to the illumination intensity detection device, and reflecting a beam with a second energy ratio in the illumination beam to the object being detected, wherein the first energy ratio is less than the second energy ratio.

[0023] As one possible embodiment, the illumination optical system includes: an illumination source, and at least one of a beam shaping device, an optical modulation device, and an illumination tube mirror arranged sequentially along the propagation direction of the illumination beam;

[0024] The illumination source is used to emit an initial beam of light;

[0025] The beam shaping device adjusts the divergence angle of the initial beam so that the initial beam has a preset aperture angle and a preset field of view.

[0026] The optical modulation device is used to select an illumination beam of a preset wavelength from the initial beam after adjusting the divergence angle.

[0027] The illumination tube is used to adjust the propagation direction of the illumination beam and to make the adjusted illumination beam incident on the coupler.

[0028] As one possible embodiment, the beam shaping device includes at least one of a lens group, a light diffuser, and a ground glass; the optical modulation device includes at least one of a filter, an attenuator, a polarizer, and an aperture; and the illumination tube lens includes a lens group.

[0029] As one possible embodiment, the imaging device is positioned in the optical path between the coupler and the object being detected via a beam splitter, along the direction of the coupled illumination beam.

[0030] As one possible embodiment, the imaging device includes an objective lens and an imaging assembly, wherein the objective lens is disposed in the optical path of the illumination beam transmitted through the beam splitter, and is used to transmit the illumination beam and the focusing beam transmitted through the beam splitter to the object being detected, and to receive the illumination beam and the focusing beam reflected by the object being detected.

[0031] The beam splitter is used to transmit the focusing beam reflected by the object being detected to the detection light emitting device, and to reflect the illumination beam reflected by the object being detected to the imaging component;

[0032] The imaging component is disposed in the optical path of the illumination beam reflected by the beam splitter, and is used to image the detection object based on the illumination beam reflected by the detection object.

[0033] As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

[0034] The optical detection system in this embodiment includes: an illumination optical system, a focusing optical system, a coupler, an illumination intensity detection device, and an imaging device. The illumination optical system is used to emit an illumination beam and illuminate the object to be detected. The focusing optical system includes a detection light emitting device and an adjustment device. The detection light emitting device is used to emit a focusing beam towards the object to obtain the distance between the object and the imaging device. The adjustment device is used to adjust the distance so that the object is located at the focal point of the imaging device. The focusing beam and the illumination beam are coupled through the coupler before illuminating the object. The illumination intensity detection device is used to detect the energy of the coupled illumination beam. The imaging device is used to image the focused object to obtain an image of the object, wherein the image of the object is used for feature detection.

[0035] Because the illumination intensity detection device in this embodiment can directly measure the energy of the coupled illumination beam, it improves the accuracy of obtaining the illumination beam energy in the optical detection system. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of one embodiment of the optical detection system in this application;

[0037] Figure 2 This is a schematic diagram of another embodiment of the optical detection system in this application;

[0038] Figure 3 This is a schematic diagram showing the transmittance of the optical film to the illumination beam and the focusing beam in the embodiments of this application;

[0039] Figure 4 This is a schematic diagram of the internal structure of the light intensity detection device in the embodiments of this application;

[0040] Figure 5 These are schematic diagrams of the internal structure of the illumination optical system 10 and the imaging device 50 in the optical detection system of this application. Detailed Implementation

[0041] This invention provides an optical detection system that can directly measure the energy (light intensity) of a coupled illumination beam using an illumination intensity detection device, thereby improving the accuracy of obtaining the illumination energy in the illumination beam.

[0042] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0043] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] For ease of understanding, the optical detection system in the embodiments of this application is described below. Please refer to [link / reference]. Figure 1 One embodiment of the optical detection system in this application includes:

[0045] The system comprises an illumination optical system 10, a focusing optical system 20, a coupler 30, an illumination intensity detection device 40, and an imaging device 50, wherein:

[0046] The illumination optical inspection system 10 is used to emit an illumination beam and illuminate the object to be inspected. In this embodiment, the object to be inspected includes wafers, chips, photomasks, glass screens, etc., and there are no specific limitations on the object to be inspected here.

[0047] The focusing optical system 20 includes a detection light emitting device 201 and an adjustment device 202. The detection light emitting device 201 is used to emit a focusing beam towards the detection object to obtain the distance between the detection object and the imaging device through the focusing beam. The adjustment device 202 is used to adjust the distance between the detection object and the imaging device so that the detection object is located at the focal point of the imaging device. The focusing beam and the illumination beam are coupled through a coupler 30 before illuminating the detection object.

[0048] Specifically, in the embodiments of this application, the illumination beam and the focusing beam are beams of different wavelengths. For example, when the illumination beam is a beam in the λ1 to λ2 wavelength range, the focusing beam is a beam in the λ3 to λ4 wavelength range. Here, there is no specific limitation on the wavelength of the illumination beam and the focusing beam.

[0049] Furthermore, the coupler in this embodiment can be a beam splitter, a dichroic mirror, or a reflector, as long as it can couple the illumination beam and the focusing beam. There are no specific restrictions on the type of coupler.

[0050] The illumination intensity detection device 40 is used to detect the energy (intensity) of the coupled illumination beam;

[0051] Imaging device 50 is used to image the focused object to obtain an image of the object, wherein the image of the object is used for feature detection, such as detecting defects in the image of the object by a processor.

[0052] This embodiment of the application differs from the prior art method of calculating the light intensity of an illumination beam by using image grayscale. Instead, it uses an illumination light intensity detection device 40 to directly detect the energy of the coupled illumination beam, thereby improving the accuracy of obtaining the energy (light intensity) of the illumination beam.

[0053] based on Figure 1 The embodiments described above are followed by a description of the optical detection system in the embodiments of this application. Please refer to [link to relevant documentation]. Figure 2 Another embodiment of the optical inspection system following the embodiments of this application includes:

[0054] The system comprises an illumination optical system 10, a focusing optical system 20, a coupler 30, an illumination intensity detection device 40, and an imaging device 50, wherein:

[0055] The illumination optical inspection system 10 is used to emit an illumination beam along a first direction and illuminate the object to be inspected. The object to be inspected in this embodiment includes wafers, chips, photomasks, glass screens, etc., and there is no specific limitation on the object to be inspected here.

[0056] The focusing optical system 20 includes a detection light emitting device 201 and an adjustment device 202. The detection light emitting device 201 is used to emit a focusing beam towards the detection object along a second direction to obtain the distance between the detection object and the imaging device through the focusing beam. The adjustment device 202 is used to adjust the distance between the detection object and the imaging device so that the detection object is located at the focal point of the imaging device. The focusing beam and the illumination beam are coupled through a coupler 30 before illuminating the detection object.

[0057] Illumination intensity detection device 40 is used to detect the intensity of the coupled illumination beam;

[0058] Imaging device 50 is used to image the focused object to obtain an image of the object, wherein the image of the object is used for feature detection, such as detecting defects in the image of the object by a processor.

[0059] Furthermore, in order to reduce the size of the optical detection system, the first direction and the second direction in this embodiment are perpendicular to each other, and the coupler 30 is a dichroic mirror used to transmit the focusing beam to the detection object, transmit the beam with the first energy ratio in the illumination beam to the illumination intensity detection device, and reflect the beam with the second energy ratio in the illumination beam to the detection object. The first energy ratio is less than the second energy ratio, such as transmitting 5% of the beam to the illumination intensity detection device and reflecting 95% of the beam to the detection object.

[0060] In this embodiment, the illumination intensity detection device 40 and the illumination optical system 10 are coaxially arranged along the direction of the illumination beam to measure the energy (intensity) of the coupled illumination beam. This coaxial arrangement of the intensity detection device 40 and the illumination optical system 10 not only improves the neatness of the optical path setup but also reduces the size of the optical path, further minimizing the space occupancy of the optical detection system.

[0061] Specifically, the light intensity detection device in this embodiment includes a first optical component 401, a photodetector 404, and a signal processing unit 405. The first optical component 401 is coated with a light film. The light film has a transmittance greater than a first threshold for the illumination beam band and a transmittance less than a second threshold for the focusing beam band, so as to receive the illumination beam from the coupled beam and isolate the focusing beam. The first threshold is greater than the second threshold.

[0062] As one possible embodiment, the optical film in this application has a transmittance of 1 for the illumination beam band and a transmittance of 0 for the focus detection beam band, thereby achieving automatic isolation of the focus detection beam. For ease of understanding, Figure 3 A schematic diagram of the transmittance of the optical film to the illumination beam and the focus beam is given.

[0063] As one possible embodiment, the first optical component in this application includes a bandpass filter, a high-pass filter, or a low-pass filter for receiving an illumination beam from the coupled beam while isolating the focusing beam.

[0064] Furthermore, since the illumination beam after passing through the first optical component is relatively weak, in order to enhance the signal of the illumination beam, the illumination intensity detection device 40 can also provide a second optical component 402 in the optical path between the first optical component 401 and the photodetector 404, so as to focus the illumination beam after passing through the first optical component onto the photodetector 404.

[0065] As one possible embodiment, the second optical component 402 includes a single focusing lens or a combination of multiple lenses to focus the illumination beam.

[0066] Furthermore, since the photodetector 404 (such as a photodiode) has its own response range to optical power, in order to improve the dynamic detection range of the photodetector to optical power, this embodiment of the application can also provide a third optical component 403 in the light intensity detection device 40. The third optical component 403 is used to attenuate the optical power of the illumination beam to the optical power response range of the photodetector 404, thereby improving the dynamic detection range of the photodetector to the optical power of the illumination beam. For ease of understanding... Figure 4 A schematic diagram of the internal structure of the light intensity detection device is given.

[0067] As one possible embodiment, the third optical component 403 in this application embodiment includes an optical attenuator.

[0068] In the light intensity detection device 40, since the second optical component 402 is perpendicular to the illumination beam to focus the illumination beam onto the photodetector, in order to avoid the first optical component 401, the third optical component 403 and the photodetector 404 reflecting the illumination beam and causing the reflected illumination beam to return to the original illumination optical path and thus affecting the original illumination optical path, in this embodiment of the application, the first optical component 401, the third optical component 403 and / or the photodetector 404 are tilted relative to the second optical component 402.

[0069] In this embodiment of the application, the internal components of the light intensity detection device 40 and the function of each component are described in detail. The first optical component 401 is used to receive the illumination beam and isolate the focusing beam, thereby realizing the acquisition of the illumination beam from the coupled beam, thus realizing the automatic measurement of the light intensity of the illumination beam by the photodetector.

[0070] based on Figure 2The following is a detailed description of the illumination optical system 10 and the imaging device 50 in the embodiments described above. Because the illumination beam emitted by the illumination optical detection system 10 needs to provide a light field (i.e., a light spot of a preset size) to the detection object before illuminating it, and in order to control the size of the light field, this embodiment requires the illumination beam to have a preset field of view angle before incident on the detection object. The larger the field of view angle, the larger the light spot. Furthermore, to improve image resolution, this embodiment requires the illumination beam to have a preset aperture angle before incident on the detection object. The larger the aperture angle, the higher the resolution of the image obtained by the imaging device, i.e., the higher the recognition rate of image details.

[0071] Therefore, the illumination beam emitted by the illumination optical system 10 in this embodiment of the application is required to have a preset aperture angle and a preset field of view. Thus, the illumination optical detection system 10 in this embodiment of the application includes an illumination source 101, and at least one of a beam shaping device 102, an optical modulation device 103 and an illumination tube lens 104 arranged sequentially along the propagation direction of the illumination beam.

[0072] The illumination source 101 is used to emit an initial beam along a first direction, and the beam shaping device 102 is used to adjust the divergence angle of the initial beam so that the initial beam has a preset aperture angle and a preset field of view angle.

[0073] As an optional embodiment, the beam shaping device 102 includes a lens group, or at least one of the lens group, a light diffuser, and a frosted glass, to make the initial beam after adjusting the divergence angle more uniform. Here, uniformity means, on the one hand, that the light intensity is the same everywhere in the preset light field illuminating the detection object (i.e., spatial uniformity), and on the other hand, that the aperture angles of the illumination beams with different divergence angles are the same in different directions (i.e., aperture angle uniformity).

[0074] Furthermore, the optical modulation device 103 is used to select an illumination beam of a preset wavelength from the initial beam. Assuming that the initial beam emitted by the illumination source 101 is a beam in the wavelength range of λ1 to λ2, the optical modulation device can be a beam with wavelength λ0 selected from the above-mentioned wavelength range.

[0075] As an optional embodiment, the optical modulation device 103 includes a filter, or a filter and at least one of elements such as an attenuator, a polarizer and an aperture, to achieve modulation of optical parameters in the illumination beam.

[0076] Furthermore, the illumination tube mirror 104 is used to adjust the propagation direction of the illumination beam of the preset wavelength band (such as λ0 wavelength) and to make the illumination beam after adjustment incident on the coupler (dichroic mirror).

[0077] As an alternative embodiment, the illumination tube lens 104 includes a single lens or a combination of multiple lenses.

[0078] Furthermore, in this embodiment, the imaging device 50 is positioned in the optical path between the coupler 30 and the object being detected via a beam splitter along the direction of the coupled illumination beam.

[0079] As an optional embodiment, the imaging device 50 in this application includes an objective lens 501 and an imaging component 502. The objective lens 501 is disposed in the optical path of the illumination beam transmitted through the beam splitter, and is used to transmit the illumination beam and the focusing beam transmitted through the beam splitter to the detection object, and to receive the illumination beam and the focusing beam reflected by the detection object. The illumination beam reflected by the detection object is used to image the detection object, while the focusing beam reflected by the detection object returns to the detection light emitting device for measuring the focal point of the objective lens.

[0080] A beam splitter is used to transmit the focusing beam reflected by the object being detected to the detection light emitting device, and to reflect the illumination beam reflected by the object being detected to the imaging assembly 502.

[0081] The imaging component 502 is positioned on the illumination beam reflected by the beam splitter and is used to image the object being detected based on the illumination beam reflected by the object being detected.

[0082] Specifically, the beam splitter in this embodiment can be coated to achieve partial transmission (e.g., 50% transmission) of the illumination beam and full transmission of the focusing beam.

[0083] For ease of understanding, Figure 5 A schematic diagram of the internal structure of the illumination optical system 10 and the imaging device 50 in the optical detection system is given.

[0084] In this embodiment, the illumination optical system includes an illumination source 101 and at least one of a beam shaping device 102, an optical modulation device 103, and an illumination tube lens 104 arranged sequentially along the propagation direction of the illumination beam, thereby enabling the illumination beam to have a preset aperture angle and a preset field of view, thus improving the recognition rate of defects in the detection object by the optical inspection system.

[0085] The imaging device 50 is positioned on the optical path of the illumination beam reflected by the beam splitter, and images the object to be detected based on the illumination beam reflected by the object to be detected, thereby further improving the cleanliness of the optical path and reducing the size of the optical detection system.

[0086] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical detection system, characterized in that The application relates to an illumination optical system, a focusing optical system, a coupler, an illumination light intensity detection device and an imaging device, wherein: The illumination optical system is used for emitting an illumination light beam and irradiating the illumination light beam to a detection object; The focusing optical system comprises a detection light emitting device and an adjusting device, wherein the detection light emitting device is used for emitting a detection light beam to the detection object to obtain a distance between the detection object and the imaging device through the detection light beam, and the adjusting device is used for adjusting the distance so that the detection object is located at a focal point of the imaging device, wherein the detection light beam and the illumination light beam are coupled through the coupler before being irradiated to the detection object; The illumination light intensity detection device is used for detecting the energy of the illumination light beam in the coupled light beam; The imaging device is used for imaging the focused detection object to obtain an image of the detection object, wherein the image of the detection object is used for feature detection. The illumination light intensity detection device is coaxially arranged with the illumination optical system along the direction of the illumination light beam.

2. The optical detection system of claim 1, wherein, The illumination light intensity detection device comprises a first optical assembly, a photoelectric detector and a signal processing unit, wherein:

3. The optical detection system of claim 1, wherein, The first optical assembly is used for receiving the illumination light beam from the coupled light beam and isolating the detection light beam; The photoelectric detector is used for converting the optical signal of the illumination light beam after the first optical assembly into an electrical signal; The signal processing unit is used for measuring the energy of the illumination light beam based on the electrical signal. The illumination light intensity detection device further comprises a second optical assembly, wherein:

4. The optical detection system of claim 3, wherein, The second optical assembly is arranged on the optical path between the first optical assembly and the photoelectric detector and is used for focusing the illumination light beam passing through the first optical assembly to the photoelectric detector. The illumination light intensity detection device further comprises a third optical assembly, wherein:

5. The optical detection system of claim 4, wherein, The third optical assembly is used for attenuating the energy of the illumination light beam passing through the second optical assembly to the energy detection range of the photoelectric detector. The first optical assembly comprises at least one of a band-pass filter, a high-pass filter and a low-pass filter, the second optical assembly comprises a lens group, and the third optical assembly comprises an optical attenuation sheet.

6. The optical detection system of claim 5, wherein, The second optical assembly is perpendicular to the illumination light beam after the first optical assembly.

7. The optical detection system of claim 4, wherein, At least one component of the first optical assembly, the third optical assembly and the photoelectric detector is arranged obliquely relative to the second optical assembly.

8. The optical detection system of claim 5, wherein, The coupler comprises a dichroic mirror, the dichroic mirror is used for transmitting the detection light beam to the detection object, transmitting the light beam with a first energy ratio in the illumination light beam to the illumination light intensity detection device and reflecting the light beam with a second energy ratio in the illumination light beam to the detection object, wherein the first energy ratio is smaller than the second energy ratio.

9. The optical detection system of claim 2, wherein, The illumination optical system comprises an illumination light source and at least one of a beam shaping device, an optical modulation device and an illumination tube lens arranged in sequence along the propagation direction of the illumination light beam; 10. The optical detection system of claim 1, wherein, The illumination light source is used for emitting an initial light beam; ​ The light beam shaping device adjusts the divergence angle of the initial light beam so that the initial light beam has a preset aperture angle and a preset field of view angle; The optical modulation device is configured to filter the illumination light beam of a preset waveband from the initial light beam after the divergence angle is adjusted. The illumination tube mirror is configured to adjust the propagation direction of the illumination light beam and make the adjusted illumination light beam incident to the coupler.

11. The optical detection system of claim 10, wherein, The light beam shaping device comprises at least one of a lens group, a homogenizing tube and ground glass, the optical modulation device comprises at least one of a filter, an attenuator, a polarizer and a diaphragm, and the illumination tube mirror comprises a lens group.

12. The optical detection system of claim 1, wherein, The imaging device is arranged on the optical path between the coupler and the detection object along the direction of the coupled illumination light beam through a beam splitter.

13. The optical detection system of claim 12, wherein, The imaging device comprises an objective lens and an imaging assembly, wherein the objective lens is arranged on the optical path of the illumination light beam transmitted through the beam splitter, configured to transmit the illumination light beam and the focus light beam transmitted through the beam splitter to the detection object, and receive the illumination light beam and the focus light beam reflected by the detection object; The beam splitter is configured to transmit the focus light beam reflected by the detection object to the detection light emitting device, and reflect the illumination light beam reflected by the detection object to the imaging assembly; The imaging assembly is arranged on the optical path of the illumination light beam reflected by the beam splitter, configured to image the detection object according to the illumination light beam reflected by the detection object.

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