A laser coaxial illumination industrial microscope system

Abstract

The application aims to provide a laser coaxial illumination industrial microscope system, which comprises an illumination device and an imaging device, the illumination device comprises a monochromatic light source module SLM, a rotating light guide column RLG, a light guide rod FLG, a mirror M1 and a shaping lens F1 along the light source; the coupling mode of the rotating light guide column RLG and the light guide rod FLG is non-contact connection; the imaging device comprises an objective lens OB, a beam splitting lens M2 and an imaging lens TV arranged on the same optical axis from the object side to the image side; the monochromatic light generated by the monochromatic light source module SLM is directly irradiated on the beam splitting lens M2 after collimation by the shaping lens F1, and then is output through the objective lens. A rotating light guide column and a light guide rod are arranged in cooperation at the illumination end, the spatial coherence of the monochromatic light is dynamically dispersed by the rotating light guide column, and multiple total reflections are generated in the transmission process of the light guide rod, so that the uniformity of the light entering the imaging device is improved, the mode noise entering the imaging device is reduced, and the speckle and precision balance problems of the monochromatic light microscope objective are solved.

Description

Technical Field

[0001] This invention relates to the field of industrial lenses, and in particular to a laser coaxial illumination industrial microscope system. Background Technology

[0002] Integrated objectives for microscopic observation and laser micromachining are core optical components of integrated equipment in fields such as micro / nano manufacturing and precision inspection. Their core principle is the fusion of high-resolution microscopic imaging and high-precision laser focusing processing, overcoming the bottlenecks of traditional discrete objectives such as large parallax, complex alignment, and low efficiency, and meeting the requirements of in-situ closed-loop processing. Currently, the semiconductor and biomedical industries are urgently seeking to improve processing precision to the sub-micron / nanometer level, requiring coaxial, multi-band compatible, and simultaneous processing and observation integrated solutions. This is driving integrated objectives to gradually replace traditional dual-objective / single-function objective architectures.

[0003] Existing microscope objectives utilize illumination spectra with limited bandwidth, requiring multi-band achromatic or apochromatic correction for these objectives. This necessitates the extensive use of cemented lenses for chromatic aberration correction. Cemented lenses are constructed by bonding various optical glasses together with adhesive layers. In laser applications, these adhesive layers become a performance bottleneck: firstly, they offer weak resistance to laser damage, especially under high-power, pulsed lasers (such as femtosecond lasers). The adhesive layer readily absorbs laser energy, leading to carbonization, aging, and even peeling or delamination, directly causing lens failure; secondly, they affect optical performance. The difference in refractive index and dispersion characteristics between the adhesive layer and the lens substrate increases laser reflection loss, generates additional aberrations, reduces laser focusing accuracy and transmittance, and the adhesive layer's poor thermal stability means that the temperature rise caused by high-power lasers will further exacerbate image distortion. Difference distortion affects the processing and observation accuracy of the system. Therefore, laser applications (especially high-energy laser scenarios) are more recommended to adopt glue-free, air-spaced lens designs to avoid various risks brought by adhesive layers. However, laser illumination will generate speckle in the imaging system, affecting the image quality. Although some lens systems use methods such as moving diffusers or mechanically vibrating optical fibers to eliminate speckle, this usually requires the introduction of additional complex mechanical structures and faces inherent defects such as large light energy loss, limited correlation of speckle patterns, and reduced spatial resolution. This makes it difficult to meet the processing accuracy requirements of fields such as semiconductors and biomedicine. Summary of the Invention

[0004] To address the aforementioned problems, this invention aims to resolve the speckle and precision balance issues present in existing monochromatic light microscope objectives. This invention proposes a laser coaxial illumination industrial microscope system. By employing a synergistic structure of a rotating light guide column and a light guide rod at the illumination end, the rotating light guide column dynamically disperses the spatial coherence of monochromatic light and generates multiple total internal reflections during transmission through the light guide rod. This improves the uniformity of the light entering the imaging device while simultaneously reducing mode noise, thus resolving the speckle and precision balance issues inherent in monochromatic light microscope objectives.

[0005] To achieve the above objectives, the laser coaxial illumination industrial microscope system of the present invention specifically includes: It includes an illumination device and an imaging device. The illumination device includes a monochromatic light source module SLM, a rotating light guide column RLG, a light guide rod FLG, a reflector M1, and a shaping lens F1, all extending from the light source. The rotating light guide column RLG and the light guide rod FLG are coupled in a non-contact manner. The imaging device includes an objective lens, a beam splitter lens M2, and an imaging lens TV arranged coaxially from the object side to the image side; The monochromatic light generated by the monochromatic light source module SLM is collimated by the shaping lens F1 and then directly incident on the beam splitting lens M2, before being output through the objective lens.

[0006] Furthermore, the rotating light guide column rotates around the central axis of the column, and the rotational speed r satisfies r≥360RPM.

[0007] Furthermore, the light guide rod FLG is made of a flexible material.

[0008] Furthermore, the material of the light guide rod FLG is transparent plastic PMMA (polymethyl methacrylate) or PC (polycarbonate).

[0009] Furthermore, the objective lens OB, from the object side to the image side, is composed of the following components in sequence: a first spherical lens L1 with positive optical power; a second spherical lens L2 with positive optical power; an aperture STO; a third spherical lens L3 with positive optical power; a fourth spherical lens L4 with positive optical power; a fifth spherical lens L5 with negative optical power; a sixth spherical lens L6 with positive optical power; a seventh spherical lens L7 with positive optical power; an eighth spherical lens L8 with negative optical power; and a ninth spherical lens L9 with negative optical power.

[0010] Furthermore, the focal length relationship between the objective lens OB and the imaging lens TV satisfies the following condition: β=f2 / f1, and 27.5≤β≤32 Where β is the absolute value of the magnification of the system device Lima, f1 is the focal length of the objective lens OB, and f2 is the focal length of the imaging lens TV.

[0011] Furthermore, the beam-splitting lens M2 has a beam-splitting film coated on the surface near the object side and an anti-reflection film coated on the other side. The transmission and reflection ratio generated by the beam-splitting film is α, that is, α = transmittance / reflectance, and satisfies: 0.1≤α≤0.9.

[0012] Furthermore, the imaging lens TV is a plano-convex single lens; its parameters satisfy the following relationship: 1.5≤nd≤2.0;180mm≤f2≤220mm Where nd represents the refractive index of the imaging lens at a wavelength of 587nm, and f2 is the focal length of the imaging lens TV.

[0013] Furthermore, the parameters of the rotating light guide column satisfy the following relationship: 100mm≤L≤300mm; 6mm≤φ≤20mm Where L is the length of the rotating light guide column, and φ is the diameter of the rotating light guide column.

[0014] In summary, this invention, in the design of a laser coaxial illumination industrial microscope system, improves the uniformity of light entering the imaging device and reduces mode noise by using a synergistic architecture of a rotating light guide column and a light guide rod at the illumination end. This is achieved by dynamically breaking down the spatial coherence of monochromatic light through the rotating light guide column and generating multiple total internal reflections during transmission through the light guide rod. Simultaneously, it solves the speckle and precision balance problem inherent in monochromatic microscope objectives. Furthermore, through the coupling of the rotating light guide column (RLG) and the light guide rod (FLG), a significant speckle reduction phenomenon can be achieved with a unit rotation speed of only 360 RPM for the rotating light guide column (RLG), avoiding the problem of single-rotor... To meet the requirements of human eye recognition efficiency, the transducer beam (RLG) at a rotation speed of 1200 RPM introduces high-frequency vibrations, affecting imaging effects. This further improves the imaging quality of the laser coaxial illumination industrial microscope system. By optimizing the focusing characteristics of the laser entering the imaging device through the combination of objective lenses, the object side can obtain an extremely small focal spot size when the laser is applied. In other words, the objective lenses further support simultaneous coaxial observation and laser processing. While the laser acts on the material, the dynamic changes of the processing area are captured in real time through the beam splitting optical path, realizing simultaneous laser processing and coaxial illumination imaging. This achieves high integration while meeting imaging accuracy and quality requirements.

[0015] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the laser coaxial illumination industrial microscope system of the present invention; Figure 2 This is an optical schematic diagram of the imaging device of the present invention; Figure 3This is a modulation transfer function image of the present invention at the corresponding A working distance of 1550nm wavelength; Figure 4 This is a modulation transfer function image of the present invention at the corresponding A working distance of 1064nm wavelength; Figure 5 This is a modulation transfer function image of the present invention at the corresponding A working distance of 808nm wavelength; Figure 6 This is a modulation transfer function image of the present invention at the corresponding A working distance of 650nm wavelength; Figure 7 This is a modulation transfer function image of the present invention at the corresponding A working distance of 532nm wavelength; Figure 8 This is a modulation transfer function image of the present invention at the corresponding A working distance of 450nm wavelength; Figure 9 This is a modulation transfer function image of the present invention at the corresponding A working distance of 405nm wavelength; Figure 10 This is an image showing the focusing performance of objective lens OB for parallel light at the corresponding working distance A according to the present invention.

[0017] Reference numerals: Lil: Illumination device; SLM: Monochromatic light source module; RLG: Rotating light guide column; FLG: Light guide rod; M1: Reflecting lens M1; F1: Optical path shaping lens; Lima: Imaging device; OB: Objective lens; L1: First spherical lens; L2: Second spherical lens; L3: Third spherical lens; L4: Fourth spherical lens; L5: Fifth spherical lens; L6: Sixth spherical lens; L7: Seventh spherical lens; L8: Eighth spherical lens; L9: Ninth spherical lens; M2: Beam splitter lens; TV: Imaging lens.

[0018] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings of the embodiments of this application. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0021] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] First, it should be known that lasers possess extremely high temporal and spatial coherence: Temporal coherence: The spectral linewidth is extremely narrow, the phase difference of light waves emitted at different times is stable, and the coherence length can reach the meter level; if ordinary white light is used for illumination, there will be no speckle problem, because the coherence length of white light is only at the micrometer level, which cannot form stable interference patterns.

[0024] Spatial coherence: The light waves at all positions on the laser cross-section are highly synchronized in phase, and the entire beam can be regarded as a single coherent wave source. Only when strong coherence is satisfied can a stable and superimposed interference effect be generated between different scattered wavelets.

[0025] In laser illumination systems, the surfaces of the components (optical elements, the target surface) appear flat macroscopically but are microscopically covered with random, uneven micro-structures. Each tiny unit independently reflects / transmits a beam of light, and these surface undulations directly cause optical path differences, resulting in corresponding phase differences between the wavelets. This leads to completely random phase shifts in the output wavelets of each micro-element. The core physical process of speckle formation is random coherent superposition. Countless coherent wavelets with random phases, the same frequency, and consistent polarization are vector-superimposed on the observation plane (corresponding to the human eye, camera detector, and imaging plane). Constructive interference forms bright speckles, while destructive interference forms dark speckles. After the superposition of massive random phases, irregular, granular, alternating bright and dark random patterns are ultimately generated, which is speckle.

[0026] In addressing the speckle problem in laser illumination systems, we initially employed a rotating light guide column to diversify the output beam angle, thereby suppressing speckle and improving image contrast. Since the energy distribution of the laser source is axially symmetrical, the speckle pattern on the output end of the light guide column rotates synchronously. Uniform rotation of this column generates multiple distinct speckle patterns, which are then time-sequentially superimposed and averaged. However, this results in uneven laser intensity distribution, and the mechanical vibrations caused by rotation affect image quality. Therefore, the inventors introduced a light guide rod at the output end of the rotating light guide column to further perform total internal reflection on the monochromatic light output. This improves the uniformity of the light entering the imaging device while simultaneously reducing mode noise during lossless energy transmission, thus resolving the speckle and precision balance issues inherent in monochromatic microscope objectives.

[0027] Please see Figure 1 The laser coaxial illumination industrial microscope system of the present invention includes: The device includes an illumination unit and an imaging unit. The illumination unit comprises a monochromatic light source module (SLM) extending from the light source, a rotating light guide column (RLG), a light guide rod (FLG), a reflector (M1), and a shaping lens (F1). The rotating light guide column (RLG) and the light guide rod (FLG) are coupled in a non-contact manner. The parameters of the rotating light guide column satisfy the following relationship: 100mm≤L≤300mm; 6mm≤φ≤20mm Where L is the length of the rotating light guide column, and φ is the diameter of the rotating light guide column.

[0028] The imaging device includes an objective lens OB, a beam-splitter lens M2, and an imaging lens TV arranged coaxially from the object side to the image side. The beam-splitter lens M2 has a beam-splitting coating on its surface near the object side and an anti-reflection coating on its other side. The transmission-to-reflection ratio produced by the beam-splitter coating is α, i.e., α = transmittance / reflectance, and satisfies: 0.1 ≤ α ≤ 0.9. The imaging lens TV is a plano-convex single lens; its parameters satisfy the following relationship: 1.5≤nd≤2.0;180mm≤f2≤220mm Where nd represents the refractive index of the imaging lens at a wavelength of 587nm, and f2 is the focal length of the imaging lens TV.

[0029] The monochromatic light generated by the monochromatic light source module SLM is collimated by the shaping lens F1 and then directly incident on the beam splitting lens M2, before being output through the objective lens.

[0030] In the operation of the above system, the laser diode LD of the monochromatic light source module SLM generates monochromatic light, which is focused by the condenser lens FO and coupled to the rotating light guide column RLG. After the rotation of the rotating light guide column RLG performs preliminary spatial decorrelation on the monochromatic light, the laser emitted from the output end of the rotating light guide column RLG is input from a section of the light guide rod FLG. Multiple total internal reflections are performed inside the light guide rod FLG to complete further spatial decorrelation and homogenization of the monochromatic light. The light guide rod FLG and the rotating light guide column RLG are coupled in a non-contact connection manner to isolate the vibration caused by the rotation of RLG from the influence of high-magnification microscope imaging. Subsequently, the laser emitted from the end face of the light guide rod FLG is rotated 90° by the reflector M1 and then passes through the shaping lens F1 and the semi-transparent and semi-reflective beam splitter M2 in sequence, so that the laser transmission direction is consistent with the optical axis of the imaging device and finally transmitted through the imaging microscope objective OB to form an illumination spot on the object surface, realizing high-precision and speckle-free imaging of the laser coaxial illumination industrial microscope system.

[0031] Furthermore, imaging jitter was still observed during the experiment. After investigation, it was found that the optimal operating condition for the average rotational speed of the rotating light guide column (RLG) under theoretically speckle-free conditions is: the light guide completes exactly one full rotation within the detector integration time, meaning a human eye can perceive a speckle-free image at a frame rate of 20 frames per second, corresponding to a single rotation time of 50 milliseconds; this translates to 1200 RPM. However, excessively high rotational speeds lead to higher frequency vibrations, thus affecting the imaging accuracy of the monochromatic microscope.

[0032] Through the aforementioned collaborative architecture of rotating light guide column (RLG) + light guide rod (FLG), the high spatial coherence of monochromatic light is divided into two parts and gradually reduced. Based on this, the present invention preferably sets the rotating light guide column to rotate around the central axis of the column, and the rotation speed r satisfies r≥360RPM (revolutions per minute), that is, at a rotation speed of 360 revolutions per minute, the requirement for eliminating speckle can be met.

[0033] Furthermore, to ensure the system's integration and controllability, the light guide rod FLG is made of a flexible material, such as transparent plastic PMMA (polymethyl methacrylate) or PC (polycarbonate). In this case, the flexible light guide rod FLG can adjust the position of the emission end of the FLG at any time to improve the integration.

[0034] In another embodiment, the objective lens OB, from the object side to the image side, is composed of the following components in sequence: a first spherical lens L1 with positive optical power; a second spherical lens L2 with positive optical power; an aperture stop STO; a third spherical lens L3 with positive optical power; a fourth spherical lens L4 with positive optical power; a fifth spherical lens L5 with negative optical power; a sixth spherical lens L6 with positive optical power; a seventh spherical lens L7 with positive optical power; an eighth spherical lens L8 with negative optical power; and a ninth spherical lens L9 with negative optical power.

[0035] By optimizing the laser focusing characteristics through this set of lenses and optical power settings, the uniform laser output from the mirror M1 can be refocused when the monochromatic light source module SLM is firing the laser. This results in a very small focal spot size on the object side, meaning the objective lens further supports coaxial observation and simultaneous laser processing. While the laser acts on the material, the dynamic changes in the processing area can be captured in real time through the beam splitting optical path.

[0036] Preferably, the focal length relationship between the objective lens OB and the imaging lens TV satisfies the following condition: β=f2 / f1, and 27.5≤β≤32 Where β is the absolute value of the magnification of the system device Lima, f1 is the focal length of the objective lens OB, and f2 is the focal length of the imaging lens TV.

[0037] The imaging results of this invention are demonstrated using a set of test data, as shown in Table 1 below. Figure 2 The structure and optical parameters of each optical element of the imaging device shown were tested. The parameters are as follows: along the direction of light propagation; thickness represents the air gap between surfaces; A represents the optical working distance of the objective lens OB (unit: mm), the specific value of A is related to the wavelength of the illumination laser, and the reference correspondence will be given in Table 2; nd and vd values ​​represent the refractive index and dispersion coefficient based on the d-line at 487 nm, respectively, while the units for radius of curvature and thickness are both mm.

[0038]

[0039] Table 1 The system parameters of the imaging device at several common laser wavelengths are described in Table 2 below:

[0040] Table 2 System parameters of the imaging device at different wavelengths The lens has a fixed working aperture, and its aperture parameter is not adjustable. Its value is expressed as the object-side numerical aperture in the table above. The working mechanism of the device is described below based on the parameters in the table. The objective lens OB of the imaging system has a working distance within a range. Different working distances correspond to different working spectra. The long working distance of 29.744 mm corresponds to a single working wavelength of 1550 nm, which can be generated by a laser diode. 1064 nm corresponds to the first harmonic wavelength of a YAG laser, and also corresponds to the second harmonic wavelength of 532 nm for this type of laser. Other wavelengths of 405 nm, 450 nm, 650 nm, and 808 nm can be excited by laser diodes, each with a corresponding working distance.

[0041] See Figures 3-9 A total of seven performance diagrams are presented, illustrating the optical modulation transfer function (MTF) at the corresponding object distance and operating wavelength in this invention. The camera target size used is 2 / 3 inch, and the diagonal length of the imaging area is 11 mm. This series of diagrams shows information from five field-of-view points, including the central field of view. The lens field of view is centrally symmetrical, and the series of field-of-view points in the +Y direction represent the image quality across the entire field of view.

[0042] See Figure 10 The objective lens OB used in this invention employs infinity-corrected aberration, making it suitable for parallel beam incidence. The beam cross-section diameter does not exceed the entrance pupil diameter, and the beam angle incident on the objective lens OB does not exceed the angle corresponding to the aforementioned 11mm diameter image plane circle. The energy concentration and performance of the focused beam spot are evaluated using an in-circle energy graph. In the graph, the horizontal axis (circle circle diameter) represents the "diameter of the focused beam spot under investigation," reflecting the spatial extent of the beam spot; the smaller the value, the closer it is to the center of the beam spot. The vertical axis (circle energy percentage) represents the "percentage of the total energy contained within this diameter range" (values ​​range from 0-1 or 0%-100%), reflecting the energy concentration; the closer the value is to 1 (100%), the more complete the energy contained within this diameter range. The core logic of this graph is that "as the beam spot diameter increases, the accumulated energy gradually increases," eventually approaching the total energy (100%). Its curve shape directly reflects the aberrations, diffraction, and energy loss of the optical system, making it particularly suitable for performance evaluation in scenarios such as laser focusing and integrated objectives.

[0043] It can be seen that the objective lens of this invention can operate at any single wavelength within the wavelength range of 405nm-1550nm, where the single wavelength is generated by the monochromatic light source laser module of the illumination section. As the wavelength of the light source used varies, the focal length of the objective lens also varies, as does the optimal working distance, and the magnification of the entire imaging section will also vary around 30x.

[0044] In summary, this invention, in the design of a laser coaxial illumination industrial microscope system, improves the uniformity of light entering the imaging device and reduces mode noise by using a synergistic architecture of a rotating light guide column and a light guide rod at the illumination end. This is achieved by dynamically breaking down the spatial coherence of monochromatic light through the rotating light guide column and generating multiple total internal reflections during transmission through the light guide rod. Simultaneously, it solves the speckle and precision balance problem inherent in monochromatic microscope objectives. Furthermore, through the coupling of the rotating light guide column (RLG) and the light guide rod (FLG), a significant speckle reduction phenomenon can be achieved with a unit rotation speed of only 360 RPM for the rotating light guide column (RLG), avoiding the problem of single-rotor... To meet the requirements of human eye recognition efficiency, the transducer beam (RLG) at a rotation speed of 1200 RPM introduces high-frequency vibrations, affecting imaging effects. This further improves the imaging quality of the laser coaxial illumination industrial microscope system. By optimizing the focusing characteristics of the laser entering the imaging device through the combination of objective lenses, the object side can obtain an extremely small focal spot size when the laser is applied. In other words, the objective lenses further support simultaneous coaxial observation and laser processing. While the laser acts on the material, the dynamic changes of the processing area are captured in real time through the beam splitting optical path, realizing simultaneous laser processing and coaxial illumination imaging. This achieves high integration while meeting imaging accuracy and quality requirements.

[0045] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A laser coaxial illumination industrial microscope system, comprising an illumination device and an imaging device, characterized in that, The lighting device includes a monochrome light source module SLM, a rotating light guide column RLG, a light guide rod FLG, a reflector M1, and a shaping lens F1, all extending from the light source; wherein the rotating light guide column RLG and the light guide rod FLG are coupled in a non-contact manner. The imaging device includes an objective lens OB, a beam splitter lens M2, and an imaging lens TV arranged coaxially from the object side to the image side; The monochromatic light generated by the monochromatic light source module SLM is collimated by the shaping lens F1 and then directly incident on the beam splitting lens M2, before being output through the objective lens.

2. The laser coaxial illumination industrial microscope system according to claim 1, characterized in that, The rotating light guide column rotates around the central axis of the column, and the rotational speed r satisfies r≥360RPM.

3. The laser coaxial illumination industrial microscope system according to claim 2, characterized in that, The light guide rod FLG is made of a flexible material.

4. The laser coaxial illumination industrial microscope system according to claim 3, characterized in that, The light guide rod FLG is made of transparent plastic PMMA (polymethyl methacrylate) or PC (polycarbonate).

5. The laser coaxial illumination industrial microscope system according to any one of claims 1-4, characterized in that, The objective lens OB, from the object side to the image side, consists of the following components in sequence: a first spherical lens L1 with positive optical power; a second spherical lens L2 with positive optical power; an aperture stop STO; a third spherical lens L3 with positive optical power; a fourth spherical lens L4 with positive optical power; a fifth spherical lens L5 with negative optical power; a sixth spherical lens L6 with positive optical power; a seventh spherical lens L7 with positive optical power; an eighth spherical lens L8 with negative optical power; and a ninth spherical lens L9 with negative optical power.

6. The laser coaxial illumination industrial microscope system according to claim 5, characterized in that, The focal length relationship between the objective lens OB and the imaging lens TV satisfies the following condition: β=f2 / f1, and 27.5≤β≤32 Where β is the absolute value of the magnification of the system device Lima, f1 is the focal length of the objective lens OB, and f2 is the focal length of the imaging lens TV.

7. The laser coaxial illumination industrial microscope system according to claim 6, characterized in that, The beam-splitting lens M2 has a beam-splitting film coated on the surface near the object side and an anti-reflection film coated on the other side. The transmission and reflection ratio produced by the beam-splitting film is α, that is, α = transmittance / reflectance, and satisfies: 0.1≤α≤0.

9.

8. The laser coaxial illumination industrial microscope system according to claim 7, characterized in that, The imaging lens TV is a plano-convex single lens; its parameters satisfy the following relationship: 1.5≤nd≤2.0;180mm≤f2≤220mm Where nd represents the refractive index of the imaging lens at a wavelength of 587nm, and f2 is the focal length of the imaging lens TV.

9. The laser coaxial illumination industrial microscope system according to claim 8, characterized in that, The parameters of the rotating light guide column satisfy the following relationship: 100mm≤L≤300mm; 6mm≤φ≤20mm Where L is the length of the rotating light guide column, and φ is the diameter of the rotating light guide column.

Images