Optical detection system

Abstract

The utility model relates to an optical detection system, an illumination end comprises a first barrel lens and more than two light sources, the light sources emit illumination light into the first barrel lens, and the first barrel lens separates the illumination light emitted by each light source into at least two non-phase line light with different characteristics through an internal functional light splitting element and transmits the non-phase line light to the surface of an object to be detected; the imaging end comprises a second barrel lens and more than one imaging module, the imaging module is arranged on the second barrel lens, the second barrel lens receives at least two non-phase line lights reflected by the object to be detected and transmits the non-phase line lights to the imaging module for imaging, image information of the non-phase line lights with different characteristics on the surface of the object to be detected can be captured, and finer and more accurate images can be obtained; and the detection precision or the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical detection technology, in particular to an optical detection system. BACKGROUND

[0002] The 3D line scanning optical detection system is an optical system for high-precision three-dimensional measurement and detection. A laser or high-power LED line light source and an industrial camera are in a fixed relative position at a certain angle to perform line scanning on the surface of an object. The industrial camera captures the position changes of the reflection points of the light on the surface of the object, and calculates the three-dimensional coordinates of each point on the surface of the measured object in real time through the triangulation method. Compared with the traditional contact measurement method, the 3D line scanning optical detection system has the advantages of non-contact and non-damage, is suitable for measuring complex shapes or surface-sensitive objects, can quickly and efficiently generate three-dimensional topographic information of the surface of the object, and is widely used in industrial detection such as semiconductor wafer detection, photoresist thickness measurement, and microstructure topography measurement of semiconductor components. However, in the traditional optical detection system, the amount of information obtained is insufficient, and there are disadvantages of low detection precision or low detection efficiency. CONTENT OF THE UTILITY MODEL

[0003] Therefore, it is necessary to provide an optical detection system capable of improving the detection precision or the detection efficiency in view of the above problems.

[0004] An optical detection system comprises an illumination end and an imaging end, wherein:

[0005] The illumination end comprises a first barrel lens and two or more light sources. The light sources emit illumination light into the first barrel lens. The first barrel lens transmits at least two non-coherent line lights with different characteristics to the surface of a measured object through an internal functional light splitting element.

[0006] The imaging end comprises a second barrel lens and one or more imaging modules. The imaging modules are arranged in the second barrel lens. The second barrel lens receives at least two non-coherent line lights reflected by the measured object and transmits the at least two non-coherent line lights to the imaging modules for imaging.

[0007] In one embodiment, the illumination end further comprises a slit element. The slit element is arranged between the light sources and the first barrel lens. The illumination light emitted by the light sources forms line light after passing through the slit element and enters the first barrel lens.

[0008] In one embodiment, the slit element comprises a first slit element and a second slit element. The light sources comprise a first light source and a second light source. The first slit element is arranged between the first light source and a transmission surface of the functional light splitting element. The second slit element is arranged between the second light source and a reflection surface of the functional light splitting element.

[0009] In one of the embodiments, the slit of at least one of the slit elements is adjustable in the width direction, so that the optical paths of the at least two non-coherent line lights are different or coincide.

[0010] In one of the embodiments, the illumination end further comprises a fiber interface module and a first objective lens module arranged in the first barrel lens, the fiber interface module is connected to the corresponding light source to transmit the illumination light to the functional light splitting element inside the first barrel lens, and the functional light splitting element inside the first barrel lens separates the non-coherent line light with different characteristics emitted by each of the light sources and transmits the non-coherent line light to the object to be measured through the first objective lens module.

[0011] The imaging end further comprises a second objective lens module arranged in the second barrel lens, and the second barrel lens receives the line light reflected by the object to be measured through the second objective lens module.

[0012] In one of the embodiments, the first objective lens module comprises a first objective lens converter and a plurality of first microscopic objective lenses with different magnifications, the first objective lens converter is arranged in the first barrel lens, each of the first microscopic objective lenses is arranged in the first objective lens converter, and the first objective lens converter can drive each of the first microscopic objective lenses to rotate relative to the first barrel lens.

[0013] The second objective lens module comprises a second objective lens converter and a plurality of second microscopic objective lenses with different magnifications, the second objective lens converter is arranged in the second barrel lens, each of the second microscopic objective lenses is arranged in the second objective lens converter, and the second objective lens converter can drive each of the second microscopic objective lenses to rotate relative to the second barrel lens.

[0014] In one of the embodiments, the first barrel lens comprises a first functional light splitting element and a first lens barrel lens arranged along the optical path, the first functional light splitting element transmits or reflects the received line light, separates the non-coherent line light with different characteristics, and outputs the non-coherent line light to the first objective lens module through the first lens barrel lens.

[0015] In one of the embodiments, the number of the imaging modules is two or more; the second barrel lens comprises a second functional light splitting element and a second lens barrel lens arranged along the optical path, the second lens barrel lens transmits the line light output by the second objective lens module to the second functional light splitting element, the second functional light splitting element transmits or reflects the received line light, separates the non-coherent line light with different characteristics, and transmits the non-coherent line light to the corresponding imaging module for imaging.

[0016] In one of the embodiments, the functional light splitting element is a dichroic mirror or a polarization light splitting element.

[0017] In one embodiment, the first barrel lens is also used to set the imaging module, and the second barrel lens is also used to access the illumination light emitted by the corresponding light source; the second barrel lens transmits the illumination light emitted by the corresponding light source to the object to be measured through the internal functional light splitting element to separate out the linear light with different characteristics; the first barrel lens separates the linear light reflected by the object to be measured through the internal functional light splitting element to obtain the linear light with different characteristics and transmits the linear light to the corresponding imaging module for imaging.

[0018] In the above optical detection system, the illumination end comprises a first barrel lens and two or more light sources, the light sources emit illumination light into the first barrel lens, the first barrel lens transmits the illumination light emitted by each light source to the surface of the object to be measured through the internal functional light splitting element to separate out at least two non-coherent linear lights with different characteristics; the imaging end comprises a second barrel lens and one or more imaging modules, the imaging modules are arranged in the second barrel lens, the second barrel lens receives the at least two non-coherent linear lights reflected by the object to be measured and transmits the linear lights to the imaging modules for imaging, so that the image information of the non-coherent linear lights with different characteristics on the surface of the object to be measured can be captured, a more fine and accurate image can be obtained, and the detection precision or detection efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the optical detection system in one embodiment;

[0020] Figure 2 It is a structural schematic diagram of the optical detection system in one embodiment;

[0021] Figure 3 It is a structural schematic diagram of the optical detection system in another embodiment;

[0022] Figure 4 It is a linear scanning schematic diagram of the surface of the object to be measured in one embodiment;

[0023] Figure 5 It is a schematic diagram of the attention area of the object to be measured in the single light source illumination detection in the prior art;

[0024] Figure 6 It is a schematic diagram of the attention area of the object to be measured when the optical paths of the two rows of linear lights are different in one embodiment;

[0025] Figure 7 It is a schematic diagram of the attention area of the object to be measured when the optical paths of the two rows of linear lights are overlapped in one embodiment. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0028] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, operations, components, parts, or combinations thereof.

[0029] In one embodiment, such as Figure 1 and Figure 2 As shown, an optical detection system is provided, including an illumination end 100 and an imaging end 200, wherein: the illumination end 100 includes a first tube lens 101 and two or more light sources, the light sources emit illumination light into the first tube lens 101, and the first tube lens 101 separates the illumination light emitted by each light source into at least two incoherent line lights with different characteristics through an internal functional beam splitter and transmits them to the surface of the object under test; the imaging end 200 includes a second tube lens 201 and one or more imaging modules, the imaging modules are disposed in the second tube lens 201, and the second tube lens 201 receives at least two incoherent line lights reflected by the object under test and transmits them to the imaging modules for imaging.

[0030] The object to be measured can be a wafer or other product that needs to be detected by surface image. The number of light sources can be two or more, such as light source A, light source B, etc. The light source can be a constant light source that provides continuous illumination light, or a stroboscopic light source that provides illumination light once in a cycle. The type of illumination light emitted by the light source is not unique, for example, the light source can be a laser light source of different wavelengths or different polarization states, or a wide-spectrum light source of different wavelengths or different polarization states, etc. Correspondingly, the functional light splitting element inside the first barrel lens 101 splits the illumination light of each light source into non-coherent line light of different characteristics, which can be non-coherent line light of different wavelengths or different polarization states. The number of imaging modules can be one or more, such as industrial camera 1, industrial camera 2, etc. The type of imaging module is also not unique, which can be a line array camera, a plane array camera, etc. When the number of imaging modules is one, the imaging module collects the reflection image of at least two non-coherent line lights of different characteristics. When the number of imaging modules is more than one, the second barrel lens 201 can also be provided with a functional light splitting element to transmit or reflect the received line light, separate the non-coherent line light of different characteristics and transmit it to the corresponding imaging module for imaging. Each imaging module can collect the reflection image of one or more line lights of different characteristics. In this embodiment, multiple imaging modules are used to collect line light of different wavelengths / polarization states, which can better image.

[0031] Specifically, the object to be measured can be moved along the preset scan path by controlling the object platform to generate displacement (i.e. preset step displacement), and then the imaging module is used for exposure and image collection to obtain the image of the concerned area on the object to be measured. The concerned area image refers to the image obtained by collecting the image of the concerned area on the object to be measured in each cycle, Figures 5 to 7Each of the boxes in the figure represents a region of interest, and the regions of interest collected in multiple times are connected in sequence. The region of interest can be determined according to the FOV (field of view) of the imaging module, for example, when the imaging module uses a linear array camera, the FOV is 1*n or 2*n pixel regions, and then the region of interest can be set to m or m / 2 FOV sizes. In each cycle, the light source flashes once or is always on, the linear array camera performs multiple exposures, and the images of all m*n pixels of the region of interest in the cycle are obtained to obtain the region of interest image. When the imaging module uses a surface array camera, the FOV is larger (which can be understood as similar to a square), and generally, the shape of each frame of image in triangulation is a strip-shaped region of interest corresponding to the shape of the linear light. In order to ensure the continuity of the strip-shaped region of interest, the preset step displacement is generally smaller than the FOV width in the displacement direction, so that two consecutive FOVs overlap. Then, a ROI (region of interest) region of a strip containing linear light can be framed in the FOV as the region of interest, and the ROI region is sequentially scanned, that is, the ROI scanning mode. The region of interest can overlap or not overlap. It can be understood that if the imaging module is a normal linear array camera, the region of interest is the region of the image spliced in multiple exposures in a cycle; if it is a TDI camera, the region of interest can also be the FOV or ROI region of the TDI camera.

[0032] In each cycle, each light source flashes once, and each imaging module performs one or more exposures to collect the reflection image of the incoherent linear light on the surface of the measured object to obtain the region of interest image in the cycle and capture the feature information of the measured object surface in real time. By combining the region of interest images collected in different cycles, the different heights of the surface of the measured object can be analyzed. By using multiple light sources to provide illumination light and using functional light splitting elements to split the illumination light emitted by each light source to form incoherent linear light with different characteristics, the image information of the incoherent linear light with different characteristics on the surface of the measured object can be captured to obtain more detailed and accurate images.

[0033] In one embodiment, as shown in FIG. 1A, the illumination end 100 further includes a fiber interface module, such as a fiber mounting interface a, a fiber mounting interface b, etc., disposed on the first barrel lens 101. Each fiber interface module is connected to a corresponding light source to transmit the illumination light to the functional light splitting element inside the first barrel lens 101. Figure 1 The illumination end can further include a first objective lens module disposed on the first barrel lens 101. The incoherent linear light with different characteristics is transmitted to the measured object through the first objective lens module.

[0034] The first barrel lens 101 specifically comprises a first functional light splitting element 110 arranged along the light path and a first barrel lens 120, the first functional light splitting element 110 transmits or reflects the received linear light, separates the incoherent linear light with different characteristics, and outputs to the first objective lens module through the first barrel lens 120. In addition, the first barrel lens 101 can further comprise a first housing, the first functional light splitting element 110 and the first barrel lens 120 are arranged in the first housing, and the fiber interface module and the first objective lens module are arranged on the first housing.

[0035] With reference to Figure 2 The first functional light splitting element 110 in the embodiment of the application can specifically adopt a dichroic mirror or a polarization light splitting element. The polarization light splitting element can specifically adopt a polarization light splitting prism or a polarization light splitting sheet. The dichroic mirror can specifically adopt a short-wave-pass dichroic mirror, a long-wave-pass dichroic mirror, a multi-band dichroic mirror, etc. The short-wave-pass dichroic mirror has high transmissivity for light below the cutoff wavelength and high reflectivity for light above the cutoff wavelength; the long-wave-pass dichroic mirror has high transmissivity for light above the starting wavelength and high reflectivity for light below the starting wavelength; and the multi-band dichroic mirror has three or more transmission or reflection wavelength bands, for example, high transmissivity for the wavelength band between the cutoff wavelength and the starting wavelength and high reflectivity for other wavelength bands.

[0036] The above specific examples only illustrate the first functional light splitting element 110, and in other embodiments, as long as two light beams with different wavelengths (or polarization states) respectively reflected and transmitted by the reflecting surface and the transmitting surface of the functional light splitting element can be reflected and transmitted along the same direction to the object to be measured.

[0037] It should be emphasized that the first functional light splitting element 110 in the application is different from the ordinary light splitting prism or light splitting sheet, which only has a single light splitting function and does not have the characteristics of selectively reflecting or transmitting light with different wavelengths or polarization states. However, the first functional light splitting element 110 in the application can reflect and transmit at least two light beams with different characteristics along the same direction without interference (or with low coherence), so as to generate two incoherent linear lights at the same time for detecting the object to be measured and improve the detection efficiency.

[0038] The first objective module can include a plurality of first microscopic objectives 130 with different magnifications and a first objective converter 140 arranged in the first lens barrel 101, each first microscopic objective 130 is arranged in the first objective converter 140, and the first objective converter 140 can drive each first microscopic objective 130 to rotate relative to the first lens barrel 101. The first lens barrel lens 120 and the first microscopic objective 130 are combined to form an infinite correction optical system, and different magnifications of the first microscopic objective 130 can be reasonably selected and combined according to actual needs to optimize the illumination, change the line width of the illumination light source through the first microscopic objective 130, and realize the zoom function of the imaging illumination.

[0039] As shown in Figure 2 and Figure 3 , the illumination end 100 also includes a slit element 150 arranged between the light source and the first lens barrel 101. The illumination light emitted by the light source forms a line of light into the first lens barrel 101 after passing through the slit element. In this embodiment, the slit element 150 includes a first slit element and a second slit element, and the light source includes a first light source (light source A) and a second light source (light source B). The first slit element is arranged between the first light source and the transmission surface of the functional light splitting element, and the second slit element is arranged between the second light source and the reflection surface of the functional light splitting element.

[0040] Specifically, the slit element 150 can be a grating sheet, which can be arranged between the optical fiber mounting interface and the first functional light splitting element 110. The light source transmits the illumination light to the optical fiber mounting interface through the optical fiber, and the light spot becomes a long and narrow line after passing through the slit element 150 at two different slit positions, forming two rows of line light. The two rows of line light pass through the first functional light splitting element 110 with functional selectivity, and two rows of line light with different spectra or different polarization states are separated.

[0041] Further, the slit of at least one slit element 150 is adjustable in the width direction position, so that the optical paths of at least two incoherent line lights are different or coincide. By adjusting the positions of the two slits of the slit element 150 in the width direction, the relative positions of the line lights emitted by the two slits in the object side of the illumination end 100 can be changed, and the width direction spacing of the line lights in the image side of the illumination end 100 can be changed to a suitable range. The distance between the two slits of the slit element 150 can be adjusted according to actual conditions, the optical paths of the two rows of line light generated are changed, and different test needs are met. When the optical paths of the two rows of line light are different Figure 6 , two different line light scanning areas can be formed in the same area of interest, which can improve the detection efficiency compared with the prior art Figure 5 which can only scan one row of line light scanning area at a time; when the optical paths of the two rows of line light coincide Figure 7), the same line light scanning area covers two different characteristics (different spectrum or different polarization state) of line light, relative to the prior art Figure 5 ) Compared with the line light of one characteristic in the line light scanning area, the embodiment of the application can obtain more abundant feature information of the surface of the object to be detected, and has higher detection accuracy.

[0042] In one embodiment, the imaging end 200 further comprises a second objective lens module arranged in the second barrel lens 201, and the second barrel lens 201 receives the line light reflected by the object to be detected through the second objective lens module. Further, as shown in Figure 2 The number of imaging modules is two or more; the second barrel lens 201 comprises a second functional light splitting element 210 and a second barrel lens 220 arranged along the optical path, the second barrel lens 220 transmits the line light output by the second objective lens module to the second functional light splitting element 210, the second functional light splitting element 210 transmits or reflects the received line light, separates the non-coherent line light of different characteristics and transmits it to the corresponding imaging module for imaging. The second functional light splitting element 210 can also use a dichroic mirror, a polarization light splitting element, etc. The function of the second functional light splitting element 210 is basically the same as that of the first functional light splitting element 110, and the difference is that the second functional light splitting element 210 transmits two beams of non-coherent line light of different characteristics from the same direction to the corresponding imaging module after splitting. In addition, the second barrel lens 201 can further comprise a second housing, and the second functional light splitting element 210 and the second barrel lens 220 are arranged in the second housing, and the imaging module and the second objective lens module are arranged on the second housing.

[0043] Different materials have different spectral responses at different wavelengths, and have different polarization reflection characteristics. For different material characteristics of the surface of the object to be detected, the first functional light splitting element 110 and the second functional light splitting element 210 with functional selectivity are used in the illumination end 100 and the imaging end 200 to selectively separate the illumination light and the imaging light into light of different spectrum or different polarization state, so that the light spot irradiated on the surface of the object to be detected is linear or strip-shaped, so as to more quickly and accurately obtain the depth information of the surface characteristics of the object to be detected, so as to realize multi-spectral detection or polarization imaging detection, so as to obtain more abundant and clear feature images, and more accurately extract detailed information from complex background.

[0044] The second objective module can include a plurality of second microscopic objectives 230 with different magnifications and a second objective converter 240 arranged in the second lens barrel 201. Each second microscopic objective 230 is arranged in the second objective converter 240, and the second objective converter 240 can drive each second microscopic objective 230 to rotate relative to the second lens barrel 201. The second microscopic objective 230 and the second lens barrel lens 220 are combined to form an infinite correction optical system. By changing the number of pixels corresponding to the line light imaging in the industrial camera through the second microscopic objective 230, the imaging can be optimized to obtain more detailed and accurate images and improve the detection accuracy of the entire system. Different magnifications of the second microscopic objective 230 can also be reasonably selected and combined according to actual needs to optimize imaging, thereby ensuring the best imaging accuracy and resolution.

[0045] By arranging a plurality of microscopic objectives with different magnifications in the illumination end 100 and the imaging end 200, respectively, and using corresponding objective converters to achieve illumination and imaging with different magnifications, different magnifications of the microscopic objectives can be reasonably selected and combined to optimize imaging and illumination for different sizes of structural features on the surface of the object to be measured, thereby ensuring the best imaging accuracy and resolution.

[0046] In one embodiment, taking a dichroic mirror as an example for the first functional light splitting element 110 and the second functional light splitting element 210, the light source can be a laser light source with different wavelengths or a wide-spectrum light source. As shown in Figures 1 to 3 In the illumination end 100, the illumination optical fibers are respectively arranged in the optical fiber mounting interface a and the optical fiber mounting interface b, and slit elements 150 are respectively added between the optical fiber mounting interface a, the optical fiber mounting interface b and the first functional light splitting element 110. The slit positions of the two slit elements 150 are different, the slit widths can be the same or different, and the slit width can be selected according to the characteristic size of the surface of the object to be measured. The illumination light emitted by the light sources A and B is introduced into the first housing through the illumination optical fibers. In this process, the light passes through the slit elements 150 with different slit positions to form two rows of line light, and the two rows of line light are separated into two rows of line light with different spectra through the dichroic mirror. After the two rows of line light are combined and magnified by the first lens barrel lens 120 and the first microscopic objective 130, they are irradiated on the same area of interest on the surface of the object to be measured, forming two rows of different field detection, as shown in Figure 4 The two rows of illumination line light are reflected on the surface of the object to be measured and enter the second microscopic objective 230 and the second lens barrel lens 220 in the imaging end 200 to be magnified again. The line light WL1 is imaged in the industrial camera 1 and the line light WL2 is imaged in the industrial camera 2 through the dichroic mirror to realize double-field simultaneous imaging detection.

[0047] In another embodiment, taking the polarizing beam splitter as an example of the first functional light splitting element 110 and the second functional light splitting element 210, the light source can be a laser light source with different polarization states or a wide-spectrum light source. If the object to be measured is a polarized material, the use of polarization imaging detection can enhance the image contrast and color saturation, more effectively highlight specific structures or features, and improve the imaging quality. Similarly, referring to Figures 1 to 3 In the illumination end 100, the illumination optical fibers are respectively installed in the optical fiber installation interface a and the optical fiber installation interface b, and the slit elements 150 are respectively added between the optical fiber installation interface a, the optical fiber installation interface b and the first functional light splitting element 110. The slit positions of the two slit elements 150 are different, and the slit widths can be the same or different. The slit width can be selected according to the characteristic size of the surface of the object to be measured. The illumination light emitted by the light sources A and B is introduced into the first housing through the illumination optical fibers. In this process, the light passes through the slit elements 150 with different slit positions to form two rows of linear light. The two rows of linear light are separated into two rows of linear light with different polarization states, s light and p light, by the polarizing beam splitter. The two rows of linear light are combined and zoomed by the first lens barrel lens 120 and the first microscope objective 130 to irradiate the same area of interest on the surface of the object to be measured, forming two rows of different field detection. After the two rows of illumination linear light are reflected by the surface of the object to be measured, the polarization state remains unchanged, and the linear light enters the second microscope objective 230 and the second lens barrel lens 220 in the imaging end 200 to be zoomed again. The linear light is selectively separated by the polarizing beam splitter, so that the linear light WL1 (s light) is imaged on the industrial camera 1, and the linear light WL2 (p light) is imaged on the industrial camera 2, realizing double-view simultaneous imaging detection.

[0048] In the above two embodiments, by using a laser light source or a wide-spectrum light source with different wavelengths or different polarization states as the illumination light source, and by using a dichroic mirror or a polarizing beam splitter with different functions, two rows of linear light with different spectra or different polarization states can be separated. The two rows of linear light irradiate the same area of interest on the surface of the object to be measured, forming two rows of different field detection. WL1 is the illumination linear light emitted by the light source A, which is captured and imaged by the industrial camera 1; WL2 is the illumination linear light emitted by the light source B, which is captured and imaged by the industrial camera 2, realizing double-view simultaneous imaging. This reduces the viewing angle blind area, covers a larger viewing angle range, improves the overall coverage rate of the system, and greatly improves the detection speed. The two rows of linear light enter the imaging end 200 after being reflected by the surface of the object to be measured. The industrial cameras in the imaging end 200 can use high-frame-rate linear array cameras or ROI mode area array cameras. The two industrial cameras simultaneously capture image information within different spectral or different polarization state ranges, and real-time high-speed acquisition of global information of the surface of the object to be measured is realized, achieving high-speed line scanning function and avoiding image blur caused by high-speed movement of the object.

[0049] In addition, the first barrel lens 101 is also used to set the imaging module, and the second barrel lens 201 is also used to access the illumination light emitted by the corresponding light source; the second barrel lens 201 transmits the linear light of different characteristics corresponding to the illumination light emitted by the corresponding light source to the object to be measured in the same direction through the internal functional light splitting element, and the first barrel lens 101 separates the linear light reflected by the object to be measured through the internal functional light splitting element, and transmits the linear light of different characteristics to the corresponding imaging module for imaging. After the positions of the light source and the imaging module are interchanged, the functions of the first functional light splitting element 110 and the second functional light splitting element 210 are also interchanged.

[0050] Specifically, the imaging module can be newly added to the first shell in the illumination end 100, or the position of the optical fiber installation interface can be replaced by the imaging module; the optical fiber installation interface can be newly added to the second shell in the imaging end 200, or the position of the imaging module can be replaced by the optical fiber installation interface. In the embodiment, the positions of the light source and the industrial camera can be adjusted and replaced according to different application requirements (for example, the positions of the industrial cameras 1 and 2 and the optical fiber installation interfaces a and b can be interchanged), and by adjusting the positions of the light source and the industrial camera, the incidence angle and distribution of the light can be optimized, thereby improving the clarity and contrast of the image, reducing unnecessary light spots and reflections, making the system more flexible and efficient, and being able to meet different application requirements, and improving the measurement accuracy and image quality of the system.

[0051] The above optical detection system provided by the application has the following advantages:

[0052] Advantage 1: Multi-spectral detection

[0053] Different wavelengths of laser or wide-spectrum light sources are used to analyze the three-dimensional profile information of the object to be measured, and a wavelength-selective light splitting element (such as a dichroic mirror) is used for wavelength separation. After the light of different spectra is reflected by the surface of the object to be measured, it enters different industrial cameras for imaging at the same time. Different materials have different spectral responses at different wavelengths, and multi-spectral detection can effectively distinguish the reflection information of different materials at different wavelengths and obtain more rich feature information of the surface of the object to be measured.

[0054] Advantage 2: Polarization imaging detection

[0055] Different polarization states of laser or wide-spectrum light sources are used to analyze the three-dimensional profile information of the object to be measured, and a polarization state-selective light splitting element (such as a polarization light splitting prism) is used for polarization state separation. After the light of different polarization states is reflected by the surface of the object to be measured, it enters different industrial cameras for imaging at the same time. Different materials have different polarization reflection characteristics, and polarization imaging detection can effectively enhance the contrast and color saturation of the image, more effectively highlight specific structures or features, and improve the imaging quality.

[0056] Advantage 3: High-speed detection

[0057] Using different wavelengths or different polarization states of laser or broadband light source as illumination light source, light passes through the slit element of different slit position to form two rows of linear light, and two rows of linear light are separated by function selective light splitting element (such as dichroic mirror, polarization light splitting prism) to form two rows of linear light with different spectrum or different polarization state. The two rows of linear light irradiate on the same attention area of the surface of the measured object, form two rows of different field of view detection, realize double field of view simultaneous imaging, so as to reduce the visual angle blind area, cover larger visual angle range, improve the overall coverage rate of the system, and greatly improve the detection speed. After the two rows of linear light are reflected on the surface of the measured object, they enter the imaging end. The imaging end adopts high frame rate linear array camera or ROI mode area array camera. Two industrial cameras capture image information in different spectrum or different polarization state range at the same time, and acquire global information of the surface of the measured object in real time and high speed.

[0058] Advantage 4: high flexibility and scalability

[0059] In semiconductor detection, different materials need to be detected by using different wavelengths or different polarization states of light source due to their physical and chemical properties. The application has a highly flexible and scalable architecture, which can quickly adjust and expand the system function according to different application requirements. For example, combined with the optical properties of different surface materials of the measured object and the specific target to be detected, the illumination end selects the appropriate light source, and the imaging end selectively assembles optical prisms with different functions (such as dichroic mirror or polarization light splitting prism), which can more effectively identify and analyze the structural features of the surface of the measured object. In addition, the positions of the light source and the industrial camera of the application can be adjusted and replaced (such as the positions of the industrial camera 1 and the fiber mounting interface b can be exchanged), by adjusting the positions of the light source and the camera, the incidence angle and distribution of the light can be optimized, so as to improve the definition and contrast of the image, reduce unnecessary light spots and reflections, make the system more flexible and efficient, meet different application requirements, and improve the measurement accuracy and image quality of the system.

[0060] Advantage 5: high precision detection

[0061] Different magnification microscopes are used in the imaging end and the illumination end for illumination and imaging. The magnification, NA, transmittance and other optical properties of the microscope will affect the overall imaging quality and detection accuracy. Combined with the structural features of different sizes on the surface of the measured object, different magnification microscopes are reasonably selected and combined to optimize imaging and illumination, the linear light width of the illumination light source is changed, and the corresponding pixel number of the linear light imaging to the industrial camera is changed, so as to obtain more fine and accurate images and improve the detection accuracy of the whole system.

[0062] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, as long as there is no conflict, any combination of the technical features should be considered within the scope of the present disclosure.

[0063] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the utility model patent. It should be pointed out that for ordinary skilled persons in the art, under the premise of not departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical detection system, characterized in that The apparatus comprises an illumination end and an imaging end, wherein: The illumination end comprises a first barrel lens and two or more light sources, the light sources emit illumination light into the first barrel lens, and the first barrel lens transmits the illumination light emitted by each of the light sources to the surface of the object to be measured through an internal functional light splitting element, and separates the illumination light into at least two non-coherent line lights with different characteristics. The imaging end comprises a second barrel lens and one or more imaging modules, the imaging modules are arranged in the second barrel lens, and the second barrel lens receives the reflection of the at least two non-coherent line lights from the object to be measured and transmits the reflection to the imaging modules for imaging.

2. The system of claim 1, wherein, The illumination end further comprises a slit element arranged between the light sources and the first barrel lens, and the illumination light emitted by the light sources forms line light after passing through the slit element and enters the first barrel lens.

3. The system of claim 2, wherein, The slit element comprises a first slit element and a second slit element, and the light sources comprise a first light source and a second light source; the first slit element is arranged between the first light source and the transmission surface of the functional light splitting element, and the second slit element is arranged between the second light source and the reflection surface of the functional light splitting element.

4. The system of claim 2 or 3, wherein, The slit of at least one of the slit elements is adjustable in the width direction, so that the optical paths of the at least two non-coherent line lights are different or coincide.

5. The system of claim 1, wherein, The illumination end further comprises a fiber interface module and a first objective lens module arranged in the first barrel lens, the fiber interface module is connected to the corresponding light source, and the fiber interface module transmits the illumination light to the functional light splitting element inside the first barrel lens; after the functional light splitting element inside the first barrel lens separates the illumination light emitted by each of the light sources into non-coherent line lights with different characteristics, the non-coherent line lights pass through the first objective lens module and are transmitted to the object to be measured. The imaging end further comprises a second objective lens module arranged in the second barrel lens, and the second barrel lens receives the reflection of the line light from the object to be measured through the second objective lens module.

6. The system of claim 5, wherein, The first objective lens module comprises a first objective lens converter and a plurality of first microscopic objective lenses with different magnifications, the first objective lens converter is arranged in the first barrel lens, each of the first microscopic objective lenses is arranged in the first objective lens converter, and the first objective lens converter can drive each of the first microscopic objective lenses to rotate relative to the first barrel lens. The second objective lens module comprises a second objective lens converter and a plurality of second microscopic objective lenses with different magnifications, the second objective lens converter is arranged in the second barrel lens, each of the second microscopic objective lenses is arranged in the second objective lens converter, and the second objective lens converter can drive each of the second microscopic objective lenses to rotate relative to the second barrel lens.

7. The system of claim 5, wherein, The first barrel lens comprises a first functional light splitting element and a first lens barrel lens arranged along the optical path, the first functional light splitting element transmits or reflects the received line light, separates the line light into non-coherent line lights with different characteristics, and outputs the non-coherent line lights to the first objective lens module through the first lens barrel lens.

8. The system of claim 5, wherein, The number of the imaging modules is two or more; the second barrel lens includes a second functional light splitting element and a second barrel lens arranged along an optical path, the second barrel lens transmits linear light output by the second objective lens module to the second functional light splitting element, the second functional light splitting element transmits or reflects the received linear light, separates linear light with different characteristics and transmits the linear light to corresponding imaging modules for imaging.

9. The system of claim 1, wherein, The functional light splitting element is a dichroic mirror or a polarization light splitting element.

10. The system of claim 1, wherein, The first barrel lens is also used for arranging the imaging modules, and the second barrel lens is also used for accessing illumination light emitted by corresponding light sources; the second barrel lens separates linear light with different characteristics from the illumination light emitted by the corresponding light sources through the internal functional light splitting element and transmits the linear light to the object to be measured, and the first barrel lens separates linear light reflected by the object to be measured through the internal functional light splitting element and obtains linear light with different characteristics and transmits the linear light to corresponding imaging modules for imaging.

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