Dual diaphragm microscope optics

Abstract

The application provides a double-aperture microscopic optical system, which comprises a light source, an aperture diaphragm, a beam splitter, an objective lens, a bearing table, a field diaphragm and a signal acquisition module; the double-aperture microscopic optical system can form an illumination light path and an imaging light path; the illumination light path is sequentially arranged by the light source, the aperture diaphragm, the beam splitter, the objective lens and a sample on the bearing table; and the imaging light path is sequentially arranged by the sample on the bearing table, the objective lens, the beam splitter, the field diaphragm and the signal acquisition module. The double-aperture microscopic optical system has high measurement precision, strong anti-interference capability and good effect on optical measurement of a micro blind hole depth-diameter ratio.

Description

Technical Field

[0001] This application relates to the field of optical precision measurement technology, and in particular to a dual-aperture microscopic optical system. Background Technology

[0002] In industrial fields such as aero-engine fuel nozzles, precision microelectronic packaging, and micro-hole processing of printed circuit boards (PCBs), high-precision, non-destructive measurement of large aspect ratio micro blind holes is a crucial quality inspection step. However, current measurement methods mainly suffer from two types of problems: First, contact measurement (such as probes or slices) is prone to scratching the precision hole walls, leading to component damage or contamination, and is inefficient, failing to meet the real-time monitoring needs of production lines. Second, although non-contact optical measurement methods can avoid physical damage, they are generally limited by stray light interference and environmental noise caused by the complex internal structure of blind holes, resulting in low signal-to-noise ratio (SNR) and blurred edge contours in the obtained images, making it difficult to accurately determine the axial position and radial dimensions of the hole opening and bottom.

[0003] To address the aforementioned issues, a Taiwanese patent document with publication number TW200526088A discloses a method for stereoscopic image measurement of blind vias on printed circuit boards. This technical solution includes equipping a measurement device for blind vias with a logic program and an image measuring device. The reference aperture and measurement stroke of the blind via to be measured are pre-input into the logic program for filing. A metallographic lens with the required magnification is selected in the image measuring device, ensuring that the metallographic lens and the blind via are aligned on the same axis. The image measuring device or the substrate is moved in steps within the measurement stroke, enabling the image measuring device to continuously focus on and capture images of the blind vias layer by layer for filing. The logic program then stacks and reassembles all captured images to read a complete stereoscopic image of the blind via. However, the above technical solutions do not include any optical design specifically for suppressing stray light. When measuring blind holes with a large depth-to-diameter ratio, stray light reflected multiple times inside the hole and reflected light from the hole surface will interfere with imaging, causing the image signal-to-noise ratio to decrease as the hole depth increases, making it difficult to guarantee measurement accuracy.

[0004] Chinese patent document CN115752285A discloses a method and device for detecting the depth of blind holes based on a coaxial illumination dual-camera single-lens system. This scheme employs a dual-camera single-lens structure, with two cameras aligned with the opening and bottom of the hole respectively. A calibration curve relating image sharpness to depth needs to be pre-established to calculate the blind hole depth. However, this scheme requires two independent camera systems and a precise optical path beam combining structure, making system assembly and adjustment difficult and demanding high stability, resulting in high manufacturing and maintenance costs, which hinders widespread application in industrial settings. Furthermore, this scheme does not specifically optimize for stray light in the imaging optical path, making its image quality susceptible to environmental interference. Under complex industrial lighting conditions, the calibration curve may drift, making it difficult to guarantee measurement accuracy.

[0005] It is important to note that the techniques described in this section are not necessarily those previously conceived or adopted. Unless otherwise specified, no technique described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be recognized in any prior art. Utility Model Content

[0006] This application provides a dual-aperture microscopic optical system, which aims to overcome the shortcomings of the prior art, effectively suppress noise from the optical source, and enable rapid, automated, and high-precision optical measurement of blind hole depth and aperture.

[0007] To achieve the above objectives, this application provides a dual-aperture microscopy optical system, which includes a light source, an aperture stop, a beam splitter, an objective lens, a stage, a field stop, and a signal acquisition module.

[0008] The dual-aperture microscopy optical system can form an illumination optical path and an imaging optical path. The illumination optical path is composed of the light source, the aperture stop, the beam splitter, the objective lens, and the sample on the stage arranged in sequence. The imaging optical path is composed of the sample on the stage, the objective lens, the beam splitter, the field stop, and the signal acquisition module arranged in sequence.

[0009] Optionally, the light source, the aperture stop, the beam splitter, the objective lens, and the support stage are arranged in order from top to bottom. The beam splitter is placed at a 45° angle. The optical paths of the light source, the aperture stop, the beam splitter, and the objective lens are coaxial. The support stage can be vertically raised and lowered along the Z-axis.

[0010] Optionally, the support platform can move horizontally along the X-axis and Y-axis respectively.

[0011] Optionally, the field stop is located on one side of the beam splitter in the horizontal direction, and the plane of the field stop is optically conjugate to the plane of the intermediate image formed by the objective lens; the signal acquisition module is located on the side of the field stop away from the beam splitter in the horizontal direction, and the horizontal light output center of the beam splitter, the center of the field stop, and the center of the photosensitive surface of the signal acquisition module are on the same optical axis.

[0012] Optionally, the light source includes a white LED and a frosted glass, wherein the frosted glass is located between the light-emitting surface of the white LED and the aperture stop, and the frosted glass is integrated into the light-emitting surface of the white LED.

[0013] Optionally, the frosted glass is a high-transmittance diffuse frosted glass, which is bonded to the light-emitting surface of the white LED through a gapless integration method.

[0014] Optionally, the aperture of the aperture stop can be adjusted.

[0015] Optionally, the aperture of the field stop can be adjusted.

[0016] Optionally, the signal acquisition module includes a charge-coupled device (CCD), which is opposite to the field stop. The center of the photosensitive surface of the CCD and the center of the field stop are on the same optical axis, and the plane of the photosensitive surface of the CCD is parallel to the plane of the field stop.

[0017] Optionally, the dual-aperture microscopy optical system includes a convex lens; the illumination optical route is composed of the light source, the convex lens, the aperture stop, the beam splitter, the objective lens, and the sample on the stage arranged in sequence.

[0018] Optionally, the light source, the convex lens, the aperture stop, the beam splitter, the objective lens, and the support stage are arranged in order from top to bottom. The beam splitter is placed at a 45° angle. The optical paths of the light source, the convex lens, the aperture stop, the beam splitter, and the objective lens are coaxial. The support stage can be vertically raised and lowered along the Z-axis.

[0019] Optionally, the light source, the convex lens, the aperture stop, the beam splitter, and the objective lens are integrated into one unit, and the field stop and the signal acquisition module are integrated into one unit.

[0020] The dual-aperture microscopic optical system of this application has the following significant advantages: 1. High signal-to-noise ratio imaging: By introducing a synergistic noise suppression mechanism of dual apertures (aperture stop + field stop), the main noise sources are effectively suppressed at the root of the optical path, resulting in clearer and more reliable images, laying a solid foundation for subsequent accurate measurements; 2. Simple and reliable structure: Only two key apertures are added to the traditional microscopic optical path, making it cost-controllable and easy to implement and promote; 3. Non-contact measurement: It avoids contact damage to precision workpieces and is suitable for the inspection of various fragile or high-value parts. Based on the above significant advantages, the dual-aperture microscopic optical system of this application effectively suppresses noise at the optical source and can achieve rapid, automated, and high-precision optical measurement of blind hole depth and aperture. Therefore, the dual-aperture microscopic optical system of this application is particularly suitable for measuring the depth-to-diameter ratio of tiny blind holes in micro-hole processing.

[0021] It should be understood that the description in this section is not intended to identify key or important features of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0022] The accompanying drawings exemplify embodiments and form part of the specification, working together with the textual description to explain exemplary implementations of the embodiments. The drawings shown are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0023] Figure 1 This is a physical image of an embodiment of the dual-aperture microscopy optical system of this application;

[0024] Figure 2 for Figure 1 A schematic diagram of the optical path in the embodiment shown.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1 Double-aperture microscopy optical system 11 light source 12 Convex lens 13 Aperture stop 14 Beam splitter 15 objective lens 16 support platform 17 Field stop 18 Signal acquisition module Detailed Implementation

[0027] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "multiple" means two or more, unless otherwise explicitly specified. The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. The term "and / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B may include three cases: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0030] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art; the terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0031] Furthermore, terms such as "exemplary," "for example," and "optional" are used to indicate illustrative purposes. Any technical solution described by the above terms in the embodiments of this application should not be construed as being more preferred or advantageous than other technical solutions. Specifically, these terms are intended to present the relevant technical concepts in terms of specific implementation methods.

[0032] This application provides a dual-aperture microscopy optical system, which includes a light source, an aperture stop, a beam splitter, an objective lens, a stage, a field stop, and a signal acquisition module. The dual-aperture microscopy optical system can form an illumination optical path and an imaging optical path. The illumination optical path is formed by sequentially arranging the light source, the aperture stop, the beam splitter, the objective lens, and the sample on the stage. The imaging optical path is formed by sequentially arranging the sample on the stage, the objective lens, the beam splitter, the field stop, and the signal acquisition module.

[0033] The dual-aperture microscopic optical system of this application has the following significant advantages: 1. High signal-to-noise ratio imaging: By introducing a synergistic noise suppression mechanism of dual apertures (aperture aperture + field aperture), the main noise sources are effectively suppressed at the root of the optical path, resulting in clearer and more reliable images, laying a solid foundation for subsequent accurate measurements; 2. Simple and reliable structure: Only two key apertures are added to the traditional microscopic optical path, making it cost-effective, easy to implement and promote; 3. Non-contact measurement: It avoids contact damage to precision workpieces and is suitable for the inspection of various fragile or high-value parts. The dual-aperture microscopic optical system of this application has high measurement accuracy and strong anti-interference ability, and can be applied to the optical measurement of the depth-to-diameter ratio of small blind holes, with particularly good results. Based on the above significant advantages, the dual-aperture microscopic optical system of this application effectively suppresses noise at the optical source and can achieve rapid, automated, and high-precision measurement of the depth and diameter of blind holes. Therefore, the dual-aperture microscopic optical system of this application is particularly suitable for measuring the depth-to-diameter ratio of small blind holes in micro-hole processing.

[0034] Please combine Figure 1 and Figure 2 The following is a detailed description of the dual-aperture microscopy optical system 1 of this application.

[0035] As described above, the dual-aperture microscopy optical system 1 of this application includes a light source 11. The light source 11 is used to emit stable and uniform illumination light to provide the energy basis for imaging. The light source 11 can be selected from types such as LED and laser, depending on the requirements.

[0036] In some embodiments, the light source 11 includes a white LED. The white LED can provide full-color visible light illumination to meet the sample's "color resolution" requirements; the white LED supports adjustable light intensity, and the brightness can be adjusted according to the sample's reflectivity to avoid overexposure or underexposure of the signal acquisition module 18; the white LED starts up quickly without preheating, unlike halogen tungsten lamps which require preheating to emit light stably, the white LED can be lit instantly, improving system efficiency (suitable for high-frequency sample detection).

[0037] In some embodiments, the light source 11 includes a frosted glass integrated into the emitting surface of the white LED and disposed below the emitting surface of the white LED. The frosted glass can achieve uniform illumination by breaking the directional light spot of the white LED through the diffusion of the micro-rough surface, outputting uniform surface light and ensuring consistent brightness in the illuminated area of ​​the sample; the frosted glass can reduce coherence noise. Although the white LED is not a completely coherent light source 11, it still has slight coherence. The diffusion effect of the frosted glass can destroy the coherence of the light and avoid interference fringes during imaging; the frosted glass can optimize the beam shape, transforming the "point light source characteristics" of the white LED into "surface light source characteristics", which is more suitable for the collimation function of the subsequent convex lens 12 (described later).

[0038] The frosted glass can be a high-transmittance diffuse-transmission type. The microscopic surface of this type of frosted glass has a rough, uneven structure. When a directional beam of light from a white LED (bright at the center, dark at the edges) is incident, the light undergoes multiple refractions and scatterings at the rough interface. This transforms the originally non-uniform beam, which propagates in a single direction, into a surface light source with uniform intensity distribution that travels along the original light path. The high transmittance (typically ≥85%) of the high-transmittance diffuse-transmission type of frosted glass means that it achieves uniform light distribution only through necessary diffusion, without excessive absorption or reflection of light. Compared to low-transmittance diffuse-transmission types (transmittance <70%), it retains more than 15% more light energy. Compared to diffuse-reflection types (only about 50% of the light travels along the original direction), the light energy loss is significantly reduced, ensuring sufficient light flux for the subsequent aperture stop 13 and objective lens 15, avoiding underexposure due to insufficient illumination.

[0039] The frosted glass is bonded to the emitting surface of the white LED using a gapless integration method (e.g., snap-fit ​​fixing, optical adhesive bonding). The frosted glass is tightly attached to the emitting surface of the white LED, ensuring that the light from the white LED is uniformly diffused through the frosted glass. This gapless integration method, or gapless bonding, avoids light reflection loss between the frosted glass and the emitting surface of the white LED; gapless integration also ensures that all emitted light from the white LED is diffused through the frosted glass, preventing some light from directly entering the convex lens 12 without uniform diffusion due to frosted glass misalignment, thus avoiding localized bright spots in the sample illumination.

[0040] As described above, the dual-aperture microscopy optical system 1 of this application includes an aperture stop 13, which is located at the light-emitting end of the light source 11, i.e., below the frosted glass. The aperture stop 13 is used to define the size of the system's entrance pupil, suppress stray light reflected from the sample surface, and simultaneously adjust the light flux and improve the imaging depth of field. The aperture of the aperture stop 13 can be adjusted. Specifically, the aperture stop 13 directly controls the beam aperture and pupil size entering the system by adjusting the size of the central light-passing aperture. The aperture stop 13 can adjust the light flux: increasing the aperture → more light passes through → brighter sample illumination → stronger signal acquisition module 18 acquires; decreasing the aperture → less light passes through → dimmer sample illumination → avoids overexposure in imaging of highly reflective samples. Aperture stop 13 controls the imaging depth of field: a smaller aperture → a smaller beam incident angle → a larger depth of field → suitable for observing the three-dimensional structure of the sample, allowing different depth regions of the sample to be clear simultaneously; a larger aperture → a larger beam incident angle → a smaller depth of field → suitable for observing fine details on the sample surface, highlighting the target area through a "shallow depth of field". Aperture stop 13 suppresses aberrations and stray light: a smaller aperture → allows the beam to pass only through the high imaging quality area in the center of objective lens 15 → reduces spherical aberration and chromatic aberration at the edges of objective lens 15 (e.g., aberrations at the edges of high-magnification objectives are more obvious, which can be improved by reducing the aperture); at the same time, the small aperture of aperture stop 13 can intercept stray light deviating from the principal optical axis, improving image contrast.

[0041] As described above, the dual-aperture microscopy optical system 1 of this application includes a beam splitter 14, which is disposed at the light-emitting end of the aperture stop 13. In some embodiments, the beam splitter 14 is located below the aperture stop 13 and is tilted at 45° (forming a 45° angle with the vertical optical path). The optical paths of the light source 11, the aperture stop 13, and the beam splitter 14 are coaxial. Although the beam splitter 14 is tilted at 45°, its center still coincides with the vertical optical axis, ensuring that the optical path is transmitted without offset. The coaxial design of the three components ensures that the illumination light output from the light source 11 (after being homogenized by the frosted glass) is incident perpendicularly to the optical axis onto the aperture stop 13, preventing some light rays from failing to pass through the center of the aperture stop 13 due to optical axis misalignment, thus reducing light flux waste. It also ensures that the beam aperture adjusted by the aperture stop 13 precisely matches the entrance pupil size of the subsequent objective lens 15, allowing the light control effect to fully act on the effective imaging area of ​​the objective lens 15, avoiding increased aberrations caused by misalignment between the light control and the objective lens 15. The beam splitter 14 couples the illumination and imaging optical paths, guiding the illumination light to the objective lens 15 while simultaneously transmitting the sample imaging light to subsequent modules, achieving spatial separation and precise connection between the illumination and imaging optical paths (detailed below). The beam splitter 14 can be selected as a semi-transparent mirror (for general imaging scenarios) or a polarizing beam splitter (for special scenarios requiring the preservation of light polarization information, such as stress detection), depending on system requirements, ensuring that the imaging signal quality is maximized while coupling the optical paths.

[0042] As described above, the dual-aperture microscopy optical system 1 of this application includes an objective lens 15, which is disposed at the light-emitting end of the beam splitter 14. In some embodiments, the objective lens 15 is located directly below the beam splitter 14, and the objective lens 15 is strictly coaxial with the vertical optical axis of the light source 11, the aperture stop 13, and the beam splitter 14. The objective lens 15 is used to focus the illumination light onto the sample surface and collect the sample imaging light to form an intermediate image. Its numerical aperture and magnification determine the system resolution and imaging size. The numerical aperture (NA) of the objective lens 15 is the upper limit of the system resolution. The larger the NA, the smaller the smallest detail size of the sample that can be resolved, which is suitable for microscopic structure observation. The magnification is directly related to the final imaging size and needs to be matched with the resolution of the subsequent signal acquisition module 18. At the same time, the working distance of the objective lens 15 (the distance between the lower end of the objective lens 15 and the sample) needs to be adapted to the vertical lifting stroke of the stage 16 to ensure that the sample can be accurately positioned at the optimal imaging focal plane of the objective lens 15 by adjusting the stage 16.

[0043] As described above, the dual-aperture microscopy optical system 1 of this application includes a stage 16, which is located at the light-emitting end of the objective lens 15. The stage 16 is used to support the sample and has precise X / Y / Z-axis adjustment functions to achieve sample positioning and focusing. The X / Y-axis adjustment of the stage 16 involves two-dimensional movement along the horizontal plane to achieve precise sample positioning. This allows the target observation area of ​​the sample to be moved to the center of the field of view of the objective lens 15, adapting to different field of view ranges of the objective lens 15. The Z-axis adjustment of the stage 16 involves vertical lifting and lowering to achieve sample focusing. By changing the distance between the sample and the objective lens 15, the sample surface is positioned precisely at the optimal imaging focal plane of the objective lens 15, adapting to samples of different thicknesses and objective lenses 15 with different magnifications. The stage 16 must have sufficient vertical lifting (Z-axis) travel because the distance between the objective lens 15 and the sample needs to be focused via Z-axis adjustment. If the Z-axis travel is insufficient, the sample may not be able to enter the working distance range of the objective lens 15, resulting in no imaging. The stage 16 must have a high degree of flatness to avoid image distortion caused by sample tilting. The movement of the stage 16 can be driven by manual fine-tuning (e.g., through precision knobs, suitable for manual operation) or electric drive (e.g., through stepper motors, combined with software to achieve automated positioning and focusing, suitable for batch sample testing). Its adjustment accuracy directly determines the ability of the dual-aperture microscopic optical system 1 to capture microscopic details.

[0044] As described above, the dual-aperture microscopy optical system 1 of this application includes a field stop 17, which is used to define the imaging field of view, block background stray light in non-measurement areas, and improve image contrast. In some embodiments, the field stop 17 is disposed on one side of the beam splitter 14 in the horizontal direction, and the plane of the field stop 17 is optically conjugate to the plane of the intermediate image formed by the objective lens 15. The field stop 17 is used to precisely define the imaging range, rather than simply blocking stray light, so its horizontal position is preferably conjugate to the intermediate image formed by the objective lens 15 (i.e., the plane of the field stop 17 is optically conjugate to the plane of the intermediate image). If the position deviates from the conjugate plane, it will cause the defined field of view to mismatch with the actual imaging range (e.g., part of the target area is blocked, or excess background stray light can still enter), which will reduce the image contrast. The precise point conjugate to the intermediate image can be found by adjusting the horizontal position of the field stop 17 (closer / farther from the beam splitter 14).

[0045] The aperture of the field stop 17 is adjustable. By adjusting the size of the central light-passing aperture, the field of view of the field of view entering the signal acquisition module 18 is directly controlled. The magnification of the objective lens 15 is inversely proportional to the field of view (low-magnification objectives have a larger field of view, and high-magnification objectives have a smaller field of view), and must be matched by adjusting the aperture of the field stop 17: low-magnification objective (e.g., 10×) → increase the field stop 17 → ensure the entire sample area enters the imaging range, without missing edge details; high-magnification objective (e.g., 100×) → decrease the field stop 17 → retain only the target area of ​​the sample, blocking surrounding background stray light. The field stop 17 can maximize image contrast. When the field stop 17 is adjusted to just cover the effective imaging range, it can completely block background light from non-measurement areas, preventing background light from diluting the sample signal. With reduced background stray light, the brightness difference of the sample is more obvious, and details are easier to distinguish. The field stop 17 can prevent the signal acquisition module 18 from receiving invalid light. If the field stop 17 is too large, the excess background light will cause the invalid area of ​​the photosensitive surface of the signal acquisition module 18 to be exposed, resulting in an overall grayish image. After adjusting it to match the field of view, the photosensitive surface only receives the valid signal of the sample, and the image is clearer.

[0046] The aperture of aperture stop 13 and the aperture of field stop 17 can be matched to achieve the best imaging effect. Aperture stop 13 and field stop 17 may each include a fine adjustment mechanism to ensure that the size of their apertures is repeatable.

[0047] As described above, the dual-aperture microscopic optical system 1 of this application includes a signal acquisition module 18, which is located at the light-emitting end of the field stop 17. The signal acquisition module 18 is used to convert optical images into electrical signals, which are then preprocessed and transmitted to the system for image storage, display, and analysis. In some embodiments, the signal acquisition module 18 is located on the side of the field stop 17 away from the horizontal direction of the beam splitter 14, and the horizontal light-emitting center of the beam splitter 14, the center of the field stop 17, and the center of the photosensitive surface of the signal acquisition module 18 are on the same optical axis.

[0048] The signal acquisition module 18 may include a charge-coupled device (CCD), which is opposite to the field stop 17. The center of the photosensitive surface of the CCD and the center of the field stop 17 are on the same optical axis, and the plane of the photosensitive surface of the CCD is parallel to the plane of the field stop 17. The CCD, as the core photoelectric conversion component, receives the sample imaging light filtered by the field stop 17. Specifically, the incident optical image is converted into a corresponding electrical signal (charge signal) through the photosensitive unit array inside the CCD. The charge signal is then converted into a digital image signal by the signal processing circuit, providing a basis for subsequent image storage, display, and analysis. The CCD possesses high sensitivity, low noise, and high spatial resolution, maximizing the optimization effects of the aperture stop 13's "light control" and the field stop 17's "limitation." The pixel size and resolution of the CCD must be compatible with the objective lens's 15x magnification. Some CCDs can further optimize image brightness and dynamic range by adjusting the exposure time in conjunction with the light flux control of the aperture stop 13.

[0049] The aforementioned positioning of the CCD ensures that the effective imaging light (containing only the light from the target area of ​​the sample) filtered by the field stop 17 is projected completely and without offset onto the photosensitive unit array of the CCD, avoiding misalignment that could cause some imaging light to overflow the CCD edge or result in insufficient utilization of the photosensitive surface. The distance between the CCD and the field stop 17 must match the optical imaging law so that the imaging range defined by the field stop 17 is precisely focused clearly on the CCD photosensitive surface, ensuring sharp image details and ultimately outputting a clear image with high contrast and no redundant information.

[0050] The arrangement of the field stop 17 and signal acquisition module 18 on the horizontal side of the beam splitter 14 achieves spatial avoidance. If the field stop 17 and signal acquisition module 18 were still arranged vertically (such as directly above the beam splitter 14), they would directly conflict with the light source 11, convex lens 12, and aperture stop 13 above them (component stacking, unable to be installed); the horizontal arrangement utilizes the light redirection function of the beam splitter 14 to extend the imaging light path from the vertical dimension to the horizontal dimension, achieving spatial separation of the illumination and imaging components. The arrangement of the field stop 17 and signal acquisition module 18 on the horizontal side of the beam splitter 14 also enables optical path matching. The 45° tilt of the beam splitter 14 converts the vertical imaging light from the sample to the objective lens 15 into horizontal light, while the horizontal arrangement of the field stop 17 and signal acquisition module 18 allows the redirected horizontal imaging light to be transmitted without loss or offset, maximizing the preservation of the integrity of the imaging signal, eliminating the need for secondary redirection by additional optical elements, and reducing light loss and aberrations.

[0051] The horizontal light outlet of the beam splitter 14, the center of the field stop 17, and the center of the photosensitive surface of the signal acquisition module 18 must be strictly aligned on the same horizontal optical axis (completely coincident with the horizontal imaging optical axis after the beam splitter 14 is rotated). If the optical axis is offset, the imaging light will not be able to completely enter the signal acquisition module 18 (such as light leakage in the edge area), resulting in problems such as "image shift, blurred edges, and uneven brightness". This can usually be ensured by adjusting the horizontal support of the field stop 17 and the signal acquisition module 18 (fine-tuning left and right / back and forth).

[0052] The dual-aperture microscopy optical system 1 of this application can form an illumination optical path and an imaging optical path. The illumination optical path is composed of a light source 11, an aperture stop 13, a beam splitter 14, an objective lens 15, and a sample on a stage 16 arranged in sequence. The imaging optical path is composed of a sample on a stage 16, an objective lens 15, a beam splitter 14, a field stop 17, and a signal acquisition module 18 arranged in sequence.

[0053] The core function of the illumination optical path is to provide uniform, controllable, and highly adaptable illumination light for the sample. The functional connection of each component in the illumination optical path is as follows: After the light source 11 emits the initial illumination light, the diverging light rays are collimated and converged by the convex lens 12 to form a parallel beam with a uniform aperture; the parallel beam passes through the aperture stop 13, and the beam aperture and luminous flux are precisely controlled (suppressing stray light while matching the numerical aperture of the objective lens 15 to prevent the beam from overflowing the objective lens 15); the beam after being adjusted by the aperture stop 13 is incident on the beam splitter 14 and reflected by the beam splitter 14 to the direction of the objective lens 15 (achieving the reversal of the illumination optical path and separating it from the imaging optical path); finally, the beam is focused by the objective lens 15 to form a high-brightness, small-spot illumination area, which is precisely applied to the sample on the stage 16, providing a clear "light signal source" for imaging.

[0054] The core function of the imaging optical path is to extract detailed information about the sample and convert it into an acquireable image signal. The functional connection of each component in the imaging optical path is as follows: After the sample on the stage 16 is illuminated by the illumination light, it reflects (or transmits) "imaging light carrying the sample's morphology / structure information," which is first collected by the objective lens 15; the objective lens 15 images the collected imaging light into an inverted real image (intermediate image) and transmits the intermediate image to the beam splitter 14; after the imaging light is transmitted through the beam splitter 14 (the reflection direction is offset from that of the illumination light to avoid interference), it is incident on the field stop 17; the field stop 17 precisely intercepts background stray light outside the intermediate image (only allowing imaging light from the target area of ​​the sample to pass through, defining the effective imaging range); finally, the filtered imaging light enters the signal acquisition module 18, is converted into an electrical signal, and then generates a clear image of the sample.

[0055] This application's dual-aperture microscopy optical system 1 creatively introduces dual-aperture collaborative light control. The aperture stop 13 (illumination end) controls the incident beam quality (intensity, depth of field), while the field stop 17 (imaging end) controls the effective imaging range. The two work together to minimize stray light interference and improve image contrast and resolution. Furthermore, this application's dual-aperture microscopy optical system 1 uses a beam splitter 14 to "reflect illumination light and transmit imaging light" (or vice versa, depending on the type of beam splitter 14), allowing the two optical paths to share core components such as the objective lens 15 and the sample. This achieves seamless "illumination-imaging" integration within a compact structure, avoiding optical path redundancy.

[0056] In some embodiments, the dual-aperture microscopy optical system 1 of this application forms an optical path with the illumination path pointing downwards and the imaging path pointing upwards. Vertical transmission of the illumination path: The illumination light emitted by the light source 11 (topmost) naturally travels downwards in the direction of gravity, passing sequentially through the lower aperture stop 13 (light control), the beam splitter 14 (direction / coupling), and finally being focused onto the sample on the stage 16 (bottommost) by the lower objective lens 15. This eliminates the need for additional optical elements to change the vertical direction of the light, reducing light energy loss and simplifying the optical path structure. Vertical return and redirection of the imaging path: The imaging light reflected from the sample returns upwards against the direction of the illumination path, first entering the upper objective lens 15 (collecting imaging light), and then traveling upwards to the beam splitter 14. The beam splitter 14 is placed at a 45° angle, redirecting the vertically upward imaging light to a horizontal direction, thereby connecting the subsequent field stop 17 and the signal acquisition module 18.

[0057] In some embodiments, the dual-aperture microscopy optical system 1 further includes a convex lens 12. The illumination light path is formed by sequentially arranging the light source 11, convex lens 12, aperture stop 13, beam splitter 14, objective lens 15, and sample on the stage 16. In some embodiments, the light source 11, convex lens 12, aperture stop 13, beam splitter 14, objective lens 15, and stage 16 are arranged from top to bottom, the beam splitter 14 is tilted at 45°, the optical paths of the light source 11, convex lens 12, aperture stop 13, and objective lens 15 are coaxial, and the stage 16 can be vertically raised and lowered along the Z-axis. The light source 11 (even with integrated frosted glass) outputs a "uniform surface light source," but the light is still slightly divergent (the frosted glass only solves the uniformity of the light spot, not the directionality). The convex lens 12, through its converging optics characteristics, can convert these divergent rays into a beam with uniform parallelism, avoiding the waste of light energy caused by divergent light. The convex lens 12 ensures precise light control of the aperture stop 13. Only when parallel light passes through the aperture stop 13 can the beam diameter be precisely controlled by adjusting the aperture size (non-parallel light will cause the light control range of the aperture stop 13 to be blurred due to divergence). This allows for matching the numerical aperture of the subsequent objective lens 15, ensuring that the objective lens 15 can fully utilize the beam and achieve optimal resolution. The light source 11, convex lens 12, aperture stop 13, beam splitter 14, objective lens 15, and stage 16 are arranged sequentially from top to bottom, forming a compact vertical optical path structure. The center of the convex lens 12 is strictly coaxial with the light source 11, aperture stop 13, and objective lens 15, which can further correct the slight off-center of the light from the light source 11, ensuring that the beam after passing through the convex lens 12 is always transmitted along the principal optical axis, avoiding edge blurring or uneven brightness in subsequent imaging due to beam deviation.

[0058] Please see Figure 1 In one embodiment, the light source 11, convex lens 12, aperture stop 13, beam splitter 14, and objective lens 15 are integrated into one unit, and the field stop 17 and signal acquisition module 18 are integrated into one unit. This enables rapid assembly of the dual-aperture microscopic optical system 1, improves optical path stability, simplifies operation, and enhances maintenance convenience. Specifically, during the pre-integration of the core illumination optical path components (light source 11 to objective lens 15), the factory has completed the optical axis coaxiality calibration (the centers of light source 11, convex lens 12, aperture stop 13, beam splitter 14, and objective lens 15 are strictly coaxial). The field stop 17 and signal acquisition module 18 are also pre-aligned with the horizontal optical axis. Users do not need to align each component individually on-site, significantly shortening the setup time of the dual-aperture microscopic optical system 1 and reducing reliance on the operator's professional skills. The integrated design utilizes mechanical structures (e.g., Figure 1The integrated housing shown in the diagram fixes the relative positions of each component, preventing optical path misalignment caused by transportation, movement, or long-term use; the optical path parameters are more stable, reducing image quality fluctuations caused by optical path drift. The two integrated modules can be used as independent units for overall debugging (e.g., adjusting the height of the illumination module to adapt to different sample thicknesses, or fine-tuning the horizontal optical axis of the moving imaging module), eliminating the need for individual operation of scattered components; simultaneously, the integrated design facilitates the integration of the dual-aperture microscopy optical system 1 into automated platforms (such as automated inspection equipment), enabling rapid docking through standardized mechanical interfaces, adapting to efficient batch sample inspection scenarios. The integrated modules reduce connection gaps and moving joints between components (such as vulnerable parts like knobs and guide rails in traditional scattered structures), resulting in fewer potential failure points; if a module malfunctions (e.g., light source aging, CCD failure), the entire module can be replaced instead of checking individual components, shortening the maintenance cycle, especially suitable for rapid recovery needs in industrial sites or laboratories.

[0059] The above embodiments are only used to illustrate the present application and are not intended to limit it. Although the present application 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 application, and should all be included within the protection scope of the present application.

Claims

1. A dual-aperture microscopy optical system, characterized in that, The dual-aperture microscopy optical system includes a light source, an aperture diaphragm, a beam splitter, an objective lens, a stage, a field diaphragm, and a signal acquisition module. The dual-aperture microscopy optical system can form an illumination optical path and an imaging optical path. The illumination optical path is composed of the light source, the aperture stop, the beam splitter, the objective lens, and the sample on the stage arranged in sequence. The imaging optical path is composed of the sample on the stage, the objective lens, the beam splitter, the field stop, and the signal acquisition module arranged in sequence.

2. The dual diaphragm micro-optical system of claim 1, wherein The light source, the aperture stop, the beam splitter, the objective lens, and the support stage are arranged in order from top to bottom. The beam splitter is placed at a 45° angle. The optical paths of the light source, the aperture stop, the beam splitter, and the objective lens are coaxial. The support stage can be vertically raised and lowered along the Z-axis.

3. The dual diaphragm micro-optical system of claim 2, wherein The field stop is located on one side of the beam splitter in the horizontal direction, and the plane of the field stop is optically conjugate to the plane of the intermediate image formed by the objective lens. The signal acquisition module is located on the side of the field stop away from the horizontal direction of the beam splitter. The horizontal light output center of the beam splitter, the center of the field stop, and the center of the photosensitive surface of the signal acquisition module are on the same optical axis.

4. The dual light diaphragm microscopic optics system of claim 1, wherein, The light source includes a white LED and a frosted glass, with the frosted glass located between the emitting surface of the white LED and the aperture stop, and the frosted glass integrated into the emitting surface of the white LED.

5. The dual light diaphragm microscopic optics system according to claim 4, wherein, The frosted glass is a high-transmittance diffuse frosted glass, which is bonded to the light-emitting surface of the white LED through a gapless integration method.

6. The dual-aperture microscopy optical system according to claim 1, characterized in that, The aperture of the aperture stop can be adjusted, and the aperture of the field stop can be adjusted.

7. The dual light-hole micro-optical system of claim 1, wherein The signal acquisition module includes a charge-coupled device (CCD), which is opposite to the field stop. The center of the photosensitive surface of the CCD and the center of the field stop are on the same optical axis, and the plane of the photosensitive surface of the CCD is parallel to the plane of the field stop.

8. The dual-aperture microscopy optical system according to any one of claims 1 to 7, characterized in that, The dual-aperture microscopy optical system includes a convex lens; The illumination optical route is composed of the light source, the convex lens, the aperture stop, the beam splitter, the objective lens, and the sample on the support stage arranged in sequence.

9. The dual light diaphragm microscopic optics system according to claim 8, wherein, The light source, the convex lens, the aperture stop, the beam splitter, the objective lens, and the support stage are arranged in order from top to bottom. The beam splitter is placed at a 45° angle. The optical paths of the light source, the convex lens, the aperture stop, the beam splitter, and the objective lens are coaxial. The support stage can be vertically raised and lowered along the Z-axis.

10. The dual light diaphragm microscopic optics system of claim 9, wherein, The light source, the convex lens, the aperture stop, the beam splitter, and the objective lens are integrated into one unit, and the field stop and the signal acquisition module are integrated into one unit.

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