Hyperspectral imaging device

Abstract

The invention discloses a hyperspectral imaging device, which is a hyperspectral system taking a micro Fourier transform spectrometer based on an MEMS micromirror as a core, and comprises a light beam processing unit, a Michelson interference system comprising an MEMS matrix micromirror, and a single / array photoelectric detector. The MEMS matrix micromirror receives an optical signal of each sub-region of the two-dimensional plane image and generates an interference signal corresponding to the optical signal. And the single / array photoelectric detector receives the interference signal and obtains a hyperspectral image cube of the detected object after processing according to the interference signal and the two-dimensional plane image, so that the function of detecting the detected object in blocks is realized. The device has the following characteristics: each micromirror of the matrix micromirror moves independently, and after light beams of the subareas are modulated, the light beams are transmitted into the single photoelectric detectors in sequence and are finally spliced into a whole image in sequence, or the light beams are transmitted into the array type photoelectric detector to realize primary imaging.

Description

Technical Field

[0001] The present invention relates to the technical field of hyperspectral imaging, and in particular to a hyperspectral imaging device based on a micro-electromechanical system (MEMS). Background Art

[0002] Spectral imaging technology is formed by the cross-fusion of spectroscopy and imaging technology. It is one of the important ways to analyze the composition and structure of substances. It can perform qualitative and quantitative analysis on samples. It is currently widely used in grain analysis, grain and oil analysis, pharmaceutical analysis, chemical analysis and other fields. The imaging data obtained by the spectral imaging device is a spectral image cube, which includes two-dimensional image information and one-dimensional spectral information.

[0003] According to the spectral resolution of the sensor, spectral imaging devices are divided into multispectral imaging devices, hyperspectral imaging devices, and hyperspectral imaging devices. The spectral resolution of multispectral imaging devices is in the order of delta_lambda / lambda=0.1, and there are generally only a few bands in the visible light and near-infrared regions. The spectral resolution of hyperspectral imaging devices is in the order of delta_lambda / lambda=0.01, and there are dozens to hundreds of bands in the visible light and near-infrared regions, and the spectral resolution can reach the nm level. The spectral resolution of hyperspectral imaging devices is in the order of delta_lambda / lambda=0.001, and can reach thousands of bands in the visible light and near-infrared regions.

[0004] At present, the photodetector used in the hyperspectral imaging device is a two-dimensional detector. A transient state can only obtain two-dimensional distribution information under a single wavelength, and it is impossible to obtain spectral information in a wider wavelength range at one time. In the prior art, spectral information in a wider wavelength range is obtained by using a filter. However, this method is only applicable to imaging in static scenes or static targets. Under complex conditions such as illumination changes, atmospheric disturbances, or in the imaging process of dynamic targets, due to the existence of multi-level interference, only spectral information containing a limited wavelength range can be obtained. In the prior art, spectral imaging methods using slits (such as prisms and grating spectroscopic systems) are also used to obtain spectral information in a wider wavelength range. However, this method will sacrifice light flux while pursuing a wide wavelength range, thereby reducing detection sensitivity. In addition, if the current hyperspectral imaging device is to perform spectral analysis of a two-dimensional plane with a resolution of N*N positions, the same number of array photodetectors (Photo Detectors) are required to obtain spectral information, which greatly increases the cost of the hyperspectral imaging device.

[0005] Therefore, it is hoped that the hyperspectral imaging device can be further improved to increase the resolution of hyperspectral imaging and reduce the cost of hyperspectral imaging. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a hyperspectral imaging device which does not require moving the object to be measured and has the characteristics of higher resolution, lower cost, wider spectral range, etc.

[0007] The present application provides a hyperspectral imaging device, comprising:

[0008] An imaging system is used to obtain a two-dimensional plane image of the object being measured;

[0009] The Michelson interferometer system is a small Fourier transform spectrometer including a MEMS matrix translation micromirror, a plane mirror / single MEMS rotation micromirror / array MEMS rotation micromirror, which receives the optical signal of each sub-region of the two-dimensional plane image and generates an interference signal corresponding thereto;

[0010] A single / array photoelectric detector receives the interference light signal and converts it into an electrical signal, which is then processed in sequence by a back-end amplifier analog-to-digital conversion circuit and a digital processing unit, and then combined with the two-dimensional plane image processing to obtain a hyperspectral image cube of the object being measured.

[0011] Optionally, the imaging system is a CMOS camera or a near-infrared camera, and the imaging system is located between the beam processing unit and the Michelson interferometer system, or between the Michelson interferometer system and a single / array photodetector.

[0012] Optionally, the Michelson interferometer system further comprises:

[0013] A first beam splitter receives a light signal from each sub-region of the two-dimensional plane image and divides the light signal into two paths.

[0014] Among them, the MEMS matrix translational micromirror receives part of the light signal output by the first beam splitter, and reflects it back to the first beam splitter after modulation. The plane mirror / single MEMS rotating micromirror / array MEMS rotating micromirror receives another light signal output by the first beam splitter and reflects it back to the first beam splitter. The first beam splitter receives the light signal modulated by the MEMS matrix translational micromirror and the light signal reflected by the plane mirror / single MEMS rotating micromirror / array MEMS rotating micromirror, and combines them to form the interference signal of the corresponding area.

[0015] Optionally, the light detector is a single structure, the MEMS matrix translational micromirror and the two-dimensional plane image are conjugate with each other, and the single photodetector obtains spectral information of different areas of the object under test at different times, and finally completes the entire image by splicing according to the order before and after data acquisition.

[0016] Optionally, the photodetector is an array structure, the array photodetector and the MEMS matrix translation micromirror are conjugate with each other, and the array photodetector array simultaneously acquires spectral information of different areas of the object under test according to the MEMS matrix translation micromirror.

[0017] Optionally, the MEMS matrix translational micromirror is a vertical large displacement MEMS micromirror, and its driving mode is selected from at least one of electrothermal driving, electrostatic driving, electromagnetic driving, and piezoelectric driving.

[0018] Optionally, the beam processing unit comprises:

[0019] A light source, directly irradiating the object to be measured; and

[0020] The second beam splitter divides the optical path of the measured object into two paths, one of which is projected to the imaging system and the other is projected to the Michelson interference system.

[0021] Optionally, the beam processing unit comprises:

[0022] light source;

[0023] a third beam splitter, which reflects the light emitted by the light source to the object to be measured, and the light is reflected by the object to be measured to the second beam splitter; and

[0024] The second beam splitter divides the optical path of the measured object into two paths, one of which is projected to the imaging system and the other is projected to the Michelson interference system.

[0025] Optionally, the light source is a coaxial broadband light source or a paraxial broadband light source or ambient light.

[0026] Optionally, the array numbers of at least two structures among the MEMS matrix translational micromirror, the array MEMS rotational micromirror, and the array photodetector are not equal.

[0027] The hyperspectral imaging device provided in the embodiment of the present application mainly includes: an imaging system, a Michelson interference system, and a light detector. After being irradiated by a light source, the light carrying the information of the object to be measured is split, one path enters the imaging system to generate a two-dimensional plane image, and the other path is received by the Michelson interference system, thereby obtaining a hyperspectral image cube containing two-dimensional image information and spectral information. The hyperspectral imaging device described above has the following characteristics: 1) A small near-infrared Fourier transform spectrometer based on a MEMS translational micromirror is used to achieve the requirements of a wide range of imaging spectral analysis, high resolution, high signal-to-noise ratio, and a small size of the imaging device; 2) One or more of the MEMS translational micromirrors and the light detector is an array structure to selectively reflect the light signal of each pixel point of the two-dimensional plane image to the light detector in sequence. Further, the MEMS translational micromirror array or the entire MEMS translational micromirror used in the present invention can selectively reflect the light signal of each pixel point in the spatial 2D plane to the beam splitter prism, and after interfering with the reflected light of the fixed mirror, it is projected onto the corresponding single light detector or light detector array. While collecting 2D spatial signals, the spectral analysis of all pixels is completed. It effectively improves the real-time performance of the hyperspectral imaging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0029] Figure 1 A schematic structural diagram of a hyperspectral imaging device provided according to an embodiment of the present invention is shown;

[0030] Figure 2 A schematic structural diagram of another hyperspectral imaging device provided according to an embodiment of the present invention is shown;

[0031] Figure 3 A schematic diagram showing a two-dimensional plane image of an object to be measured, a cross section of a MEMS translational micromirror, and a cross section of a light detector in a hyperspectral imaging device according to an embodiment of the present invention;

[0032] Figure 4 A schematic diagram showing a two-dimensional plane image of an object to be measured, a cross section of a MEMS translational micromirror, and a cross section of a light detector in another hyperspectral imaging device according to an embodiment of the present invention;

[0033] Figure 5 A schematic diagram showing a two-dimensional plane image of an object to be measured, a cross section of a MEMS translational micromirror, and a cross section of a light detector in another hyperspectral imaging device according to an embodiment of the present invention;

[0034] Figure 6A schematic diagram showing a two-dimensional plane image of a measured object, a cross section of a MEMS translational micromirror, a cross section of a fixed mirror, and a cross section of a light detector in yet another hyperspectral imaging device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0036] Many specific details of the present invention are described below, such as component structures, materials, dimensions, processing techniques and technologies, in order to more clearly understand the present invention. However, as those skilled in the art will appreciate, the present invention may be implemented without following these specific details.

[0037] Hyperspectral imaging devices are used to obtain nearly continuous spectral data for each pixel while acquiring a large number of narrow-band continuous spectral images of ground objects. Among them, Fourier transform spectrometers have gradually become a research hotspot in the field of spectral technology, especially near-infrared and infrared spectroscopy, due to their advantages such as high spectral resolution, high light flux and high signal-to-noise ratio. Fourier transform spectrometers (FTS) split a light beam into two or more components, and then combine them again after interference to obtain higher-resolution spectral information. Fourier transform spectrometers are based on the Michelson interference system and consist of a fixed mirror and a moving mirror. The working principle of the Michelson interference system is to divide an incident light beam into two beams through a beam splitter and then reflect them back by the corresponding plane mirror. Because the two light beams have the same frequency, the same vibration direction and a constant phase difference (i.e., they meet the interference condition), interference can occur. Furthermore, the incident light signal (carrying the information of the object to be measured) is converted into an interference signal by the Michelson interferometer scanned by the moving mirror. The light detector receives the interference signal with the information of the object to be measured, and then the computer software can obtain the spectral image cube of the object to be measured through Fourier transformation. The fixed mirror and the moving mirror in the Fourier transform spectrometer are often implemented with MEMS (Micro Electro Mechanical System) micromirrors. MEMS micromirrors are micro mirrors that can rotate or move vertically based on MEMS actuators.

[0038] The hyperspectral imaging device disclosed in the present application is described by taking a hyperspectral imaging device based on a small Fourier transform spectrometer of a MEMS translational micromirror as an example.

[0039] Figure 1 A schematic structural diagram of a hyperspectral imaging device provided according to an embodiment of the present invention is shown.

[0040] like Figure 1As shown, the hyperspectral imaging device 100 includes a beam processing unit, an imaging system 141 , a Michelson interference system 160 , and a light detector 180 . The beam processing unit includes a light source 121 and a second beam splitter 130 .

[0041] The light source 121 directly illuminates the object 200 to obtain a light path carrying information of the object. The light source 121 can be a paraxial broadband light source, an ambient light source, or a coaxial broadband light source.

[0042] The light path carrying the information of the measured object is split by the second beam splitter 130, one path enters the imaging system 141 to generate a two-dimensional plane image, and the other path is received by the Michelson interferometer system 160 and generates a corresponding interference signal. The Michelson interferometer system 160 is a small Fourier transform spectrometer including a MEMS matrix micromirror 162.

[0043] The light detector 180 receives the interference signal sent by the Michelson interferometer system 160 , and obtains a hyperspectral image cube of the measured object 200 based on the interference signal and the two-dimensional plane image after processing.

[0044] In this embodiment, the MEMS matrix micromirror 162 is an array structure, and the photodetector 180 is a single or array structure.

[0045] Further, the Michelson interference system 160 is responsible for modulating the complex light. The Michelson interference system 160 includes a first beam splitter 161, a MEMS matrix micromirror 162, and a fixed mirror 163. The first beam splitter 161 receives the optical signal of each pixel of the two-dimensional plane image, and divides the reflected optical signal into two paths. The MEMS matrix micromirror 162 receives one optical signal output by the first beam splitter 161, modulates it and reflects it back to the first beam splitter 161. The fixed mirror 163 receives another optical signal output by the first beam splitter 161 and reflects it back to the first beam splitter 161. The first beam splitter 161 receives the optical signal modulated by the MEMS matrix micromirror 162 and the optical signal reflected by the fixed mirror 163, and combines them to form an interference signal. Further, the MEMS matrix micromirror 162 is a vertical large displacement MEMS micromirror, and its driving mode is selected from at least one of electrothermal driving, electrostatic driving, electromagnetic driving, and piezoelectric driving. Furthermore, the horizontal displacement or inclination control of the MEMS matrix micromirror 162 adopts, for example, the electrothermal driving principle, so that the MEMS micromirror maintains a long-distance ultra-small inclination horizontal displacement, thereby making the linear motion distance in the MEMS actuator larger. The light detector 180 converts the interfering complex light signal into an electrical signal, which is then converted into a digital signal through analog-to-digital conversion, and the digital signal is processed and Fourier transformed to obtain a spectral image cube. Then, the composition and content of the sample are analyzed by software by analyzing the characteristic values ​​of the frequency domain spectrum line. The spectral image cube contains the planar two-dimensional spatial image information of the object 200 to be measured and the one-dimensional spectral information corresponding to the two-dimensional spatial image information, and the acquired data forms a three-dimensional data set. The spectral dimension is composed of several bands in the spectral space. The spectral image cube makes it possible to perform image analysis and identification of the ground object based on the image features in the spatial section, and perform spectral feature analysis of the ground object based on the spectral features in the spectral dimension, thereby identifying the type, component and content of the ground object (the object 200 to be measured).

[0046] Furthermore, the fixed mirror 163 may be a plane mirror / a single MEMS rotating micromirror / an array MEMS rotating micromirror.

[0047] In other embodiments, the hyperspectral imaging device 100 further includes a first lens group 150 disposed between the second beam splitter 130 and the Michelson interference system 160. The first lens group 150 includes a plurality of lenses disposed opposite to each other, and further includes a lens 152 and a lens 151 disposed opposite to each other.

[0048] In other embodiments, the hyperspectral imaging device 100 further includes a second lens group 110, which is disposed between the measured object 200 and the second beam splitter 130. The second lens group 110 includes a plurality of lenses disposed opposite to each other. Furthermore, the second lens group 110 includes a lens 112 and a lens 111 disposed opposite to each other.

[0049] In other embodiments, the hyperspectral imaging device 100 further includes a third lens group 170, which is disposed between the first beam splitter 161 of the Michelson interference system 160 and the light detector 180. The third lens group 170 includes a plurality of lenses disposed opposite to each other. Further, the third lens group 170 includes a lens 171 and a lens 172 disposed opposite to each other. The lens 171 is disposed on the light exit surface of the Michelson interference system 160. The lens 172 is disposed on the light incident surface of the light detector 180.

[0050] In other embodiments, the hyperspectral imaging device 100 further includes a lens 142 for transmitting another light path split by the second beam splitter 130 to the Michelson interference system 160 .

[0051] Further, the imaging system 141 is a CMOS camera or a near-infrared camera, and the imaging system 141 is located between the beam processing unit and the Michelson interferometer system 160, or between the Michelson interferometer system 160 and the single / array photodetector 180. Exemplarily, the imaging system 141 may be located between the lens 111 and the first lens group 150, or between the first lens group 150 and the Michelson interferometer system 160.

[0052] Figure 2 A schematic structural diagram of another hyperspectral imaging device provided according to an embodiment of the present invention is shown.

[0053] like Figure 2 As shown, the hyperspectral imaging device 300 includes a beam processing unit, an imaging system 141 , a Michelson interference system 160 , and a light detector 180 . The beam processing unit includes a light source 122 , a third beam splitter 111 , and a second beam splitter 130 .

[0054] The light emitted by the light source 122 is reflected by the third beam splitter 111 to the object 200, and then the light is reflected by the object 200 to the second beam splitter 130. The light source 122 can be a paraxial broadband light source or an ambient light or a coaxial broadband light source.

[0055] The light path carrying the information of the measured object is split by the second beam splitter 130, one path enters the imaging system 141 to generate a two-dimensional plane image, and the other path is received by the Michelson interferometer system 160 and generates a corresponding interference signal. The Michelson interferometer system 160 is a small Fourier transform spectrometer including a MEMS matrix micromirror 162.

[0056] The light detector 180 receives the interference signal sent by the Michelson interferometer system 160 , and obtains a hyperspectral image cube of the measured object 200 based on the interference signal and the two-dimensional plane image after processing.

[0057] In this embodiment, the MEMS matrix micromirror 162 and the photodetector 180 are a single photodetector or a detector array.

[0058] Further, the Michelson interference system 160 is responsible for modulating the complex light. The Michelson interference system 160 includes a first beam splitter 161, a MEMS matrix micromirror 162, and a fixed mirror 163. The first beam splitter 161 receives the optical signal of each pixel of the two-dimensional plane image, and divides the reflected optical signal into two paths. The MEMS matrix micromirror 162 receives one optical signal output by the first beam splitter 161, modulates it and reflects it back to the first beam splitter 161. The fixed mirror 163 receives another optical signal output by the first beam splitter 161 and reflects it back to the first beam splitter 161. The first beam splitter 161 receives the optical signal modulated by the MEMS matrix micromirror 162 and the optical signal reflected by the fixed mirror 163, and combines them to form an interference signal. Further, the MEMS matrix micromirror 162 is a vertical large displacement MEMS micromirror, and its driving mode is selected from at least one of electrothermal driving, electrostatic driving, electromagnetic driving, and piezoelectric driving. Furthermore, the horizontal displacement or inclination control of the MEMS matrix micromirror 162 adopts, for example, the electrothermal driving principle, so that the MEMS micromirror maintains a long-distance ultra-small inclination horizontal displacement, thereby making the linear motion distance in the MEMS actuator larger. The light detector 180 converts the interfering complex light signal into an electrical signal, which is then converted into a digital signal through analog-to-digital conversion, and the digital signal is processed and Fourier transformed to obtain a spectral image cube. Then, the composition and content of the sample are analyzed by software by analyzing the characteristic values ​​of the frequency domain spectrum line. The spectral image cube contains the planar two-dimensional spatial image information of the object 200 to be measured and the one-dimensional spectral information corresponding to the two-dimensional spatial image information, and the acquired data forms a three-dimensional data set. The spectral dimension is composed of several bands in the spectral space. The spectral image cube makes it possible to perform image analysis and identification of the ground object based on the image features in the spatial section, and perform spectral feature analysis of the ground object based on the spectral features in the spectral dimension, thereby identifying the type, component and content of the ground object (the object 200 to be measured).

[0059] Furthermore, the fixed mirror 163 may be a plane mirror / a single MEMS rotating micromirror / an array MEMS rotating micromirror.

[0060] In other embodiments, the hyperspectral imaging device 300 further includes a first lens group 150 disposed between the second beam splitter 130 and the Michelson interference system 160 , including a lens 152 and a lens 151 disposed opposite to each other.

[0061] In other embodiments, the hyperspectral imaging device 300 further includes a lens 114 and a lens 115 , and the lens 114 and the lens 115 are respectively disposed on two sides of the third beam splitter 111 .

[0062] In other embodiments, the hyperspectral imaging device 300 further includes a third lens group 170, which is disposed between the first beam splitter 161 of the Michelson interference system 160 and the light detector 180. The third lens group 170 includes a plurality of lenses disposed opposite to each other. Further, the third lens group 170 includes a lens 171 and a lens 172 disposed opposite to each other. The lens 171 is disposed on the light exit surface of the Michelson interference system 160. The lens 172 is disposed on the light incident surface of the light detector 180.

[0063] In other embodiments, the hyperspectral imaging device 300 further includes a lens 142 for transmitting another light path split by the second beam splitter 130 to the Michelson interference system 160 .

[0064] Further, the imaging system 141 is a CMOS camera or a near-infrared camera, and the imaging system 141 is located between the beam processing unit and the Michelson interferometer system 160, or between the Michelson interferometer system 160 and the single / array photodetector 180. Exemplarily, the imaging system 141 may be located between the lens 111 and the first lens group 150, or between the first lens group 150 and the Michelson interferometer system 160.

[0065] The following describes in detail different implementations of the MEMS matrix micromirror 162, the fixed mirror 163, and the light detector 180 in the above-mentioned different hyperspectral imaging devices. That is, the following different implementations of the MEMS matrix micromirror 162, the fixed mirror 163, and the light detector 180 are applicable to the hyperspectral imaging device 100 and the hyperspectral imaging device 300.

[0066] Figure 3 A schematic diagram showing a two-dimensional plane image of a measured object, a cross section of a MEMS translational micromirror, and a cross section of a light detector in a hyperspectral imaging device according to an embodiment of the present invention is shown.

[0067] like Figure 3 As shown, the MEMS translational micromirror 1621 is a whole micromirror, the fixed mirror 163 is a single MEMS rotating micromirror or a whole ordinary plane mirror, and the light detector 180 is an array structure. The two-dimensional plane image 10 of the object 200 to be measured transmitted to the Michelson interferometer system 160 through the lens 142 includes a plurality of pixel points 11 arranged in an array.

[0068] Furthermore, the light detector 180 array is conjugate with the two-dimensional plane image 10. The light detector 180 array vibrates back and forth with the MEMS translation micromirror 162 to obtain spectral information of different regions of the object 200 under test.

[0069] Figure 4A schematic diagram showing a two-dimensional plane image of an object to be measured, a cross section of a MEMS translational micromirror, and a cross section of a light detector in another hyperspectral imaging device according to an embodiment of the present invention is shown.

[0070] like Figure 4 As shown, the MEMS matrix micromirror 162 is an array structure, the fixed mirror 163 is a single MEMS rotating micromirror or a whole ordinary plane mirror, and the light detector 180 is a single structure. The two-dimensional plane image 10 of the object 200 to be measured, which is transmitted to the Michelson interference system 160 through the lens 142, includes a plurality of pixel points 11 arranged in an array. Further, the MEMS matrix micromirror 162 array and the two-dimensional plane image 10 are conjugate with each other, and the light detector 180 obtains the spectral information of different areas of the object 200 to be measured at different times. That is, when the subunits at different positions on the MEMS matrix micromirror 162 array vibrate back and forth in sequence over time, the spectral information of different areas on the object 200 to be measured can be read through the interference signals received by the single light detector 180 at different times.

[0071] Furthermore, in other embodiments, an imaging system is also included between the MEMS matrix micromirror 162 array and the single light detector 180. Exemplarily, the imaging system (not shown in the figure) is located between the first beam splitter 161 and the light detector 180 to proportionally reduce the size of the 2D spectral information. In this way, a smaller light detector 180 can be used to receive the interference signal, further saving the cost of the system.

[0072] Figure 5 A schematic diagram showing a two-dimensional plane image of a measured object, a cross section of a MEMS translational micromirror, and a cross section of a light detector in yet another hyperspectral imaging device according to an embodiment of the present invention is shown.

[0073] like Figure 5As shown, the MEMS matrix micromirror 162 is an array structure, the fixed mirror 163 is a single MEMS rotating micromirror or an ordinary plane mirror / single / array rotating micromirror, and the light detector 180 is an array structure. The two-dimensional plane image 10 of the object 200 to be measured, which is transmitted to the Michelson interference system 160 through the lens 142, includes a plurality of pixel points 11 arranged in an array. Further, the MEMS matrix micromirror 162 array and the light detector 180 array are conjugate with each other with the two-dimensional plane image 10, and the light detector 180 array obtains the spectral information of different regions of the object 200 to be measured as the MEMS matrix micromirror 162 array vibrates back and forth. That is, when the pixels on the MEMS matrix micromirror 162 array vibrate in sequence, the corresponding subunits in the light detector 180 array receive interference signals, and the spectral information of different regions on the object 200 to be measured can be read. Further, when the subunits on the MEMS matrix micromirror 162 array and the light detector 180 array are working, they are not limited to the working of a single subunit, but also include the situation where multiple subunits work at the same time.

[0074] Figure 6 A schematic diagram showing a two-dimensional plane image of a measured object, a cross section of a MEMS translational micromirror, a cross section of a fixed mirror, and a cross section of a light detector in yet another hyperspectral imaging device according to an embodiment of the present invention.

[0075] like Figure 6 As shown, the MEMS matrix micromirror 162 is an array structure, the fixed mirror 163 is an array structure, and the light detector 180 is an array structure. The two-dimensional plane image 10 of the object 200 to be measured transmitted to the Michelson interference system 160 through the lens 142 includes a plurality of array-arranged pixel points 11. Further, the fixed mirror 163 array is conjugated with the MEMS matrix micromirror 162 array and the two-dimensional plane image 10.

[0076] Furthermore, the fixed mirror 163 is a flip-type MEMS micromirror, and the fixed mirror 163 array flips only one sub-fixed mirror 163 corresponding to the sub-MEMS matrix micromirror 162 that vibrates back and forth in the MEMS matrix micromirror 162 array at different times. That is, when the pixels at different positions on the MEMS matrix micromirror 162 array vibrate back and forth in sequence over time, the corresponding sub-units in the fixed mirror 163 array flip and interfere with it. The pixels in the remaining areas reflect the light to other places and do not enter the photosensitive surface of the light detector 180. Through the interference signals received by the light detector 180 array at different times, the spectral information of different areas on the object 200 to be measured can be read. This solution can have a better signal-to-noise ratio.

[0077] It should be noted that the fixed mirror 163 can be a plane mirror, or a single rotating MEMS micromirror or a rotating array MEMS micromirror, and its function is to correct the error caused by the movement of the MEMS matrix micromirror 162, thereby optimizing the interference effect.

[0078] In the above-mentioned hyperspectral imaging device, the implementation method in which only one of the MEMS matrix micromirror 162 and the photodetector 180 is an array structure can reduce costs. The MEMS matrix micromirror 162 and the photodetector 180 are both array structures, which can effectively improve the real-time performance of hyperspectral imaging. An imaging system is set between the MEMS matrix micromirror 162 array and the single photodetector 180, and the size of the photodetector 180 can be reduced, further saving the cost of the system. On the basis of the MEMS matrix micromirror 162 array and the single photodetector 180, the fixed mirror 163 is set as an array structure, and the fixed mirror 163 is a flip-type MEMS micromirror, which can prevent the pixels in the remaining areas from reflecting to the photosensitive surface of the photodetector 180, so that the scheme can have a better signal-to-noise ratio.

[0079] In other embodiments, the hyperspectral imaging device further includes a MEMS micromirror disposed on the light incident surface of the Michelson interferometer system 160 , and configured to selectively inject the light signal of each pixel point of the two-dimensional plane image into the Michelson interferometer system 160 in sequence.

[0080] Furthermore, when the MEMS matrix micromirror 162 is an array structure, the fixed mirror 163 is a single structure, and the photodetector 180 is a single structure, each micromirror on the MEMS matrix micromirror 162 array moves to modulate the light beam in the sub-area, and then transmits the modulated light beam to the single photodetector 180 in sequence, and finally splices them into a whole image in sequence.

[0081] Furthermore, when the MEMS matrix micromirror 162 is an array structure, the fixed mirror 163 is a single structure, and the light detector 180 is an array structure, each micromirror on the MEMS matrix micromirror 162 array moves to modulate the light beam in the sub-area, and then transmits the modulated light beam to the light detector 180 array at one time without the need for subsequent splicing.

[0082] It should be noted that the number of arrays of at least two structures among the MEMS matrix micromirror 162 array, the fixed mirror 163 array, and the light detector 180 array may not be equal. In other embodiments, the number of arrays of at least two structures among the MEMS matrix micromirror 162 array, the fixed mirror 163 array, and the light detector 180 array may be equal and correspond one to one.

[0083] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprises one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0084] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A hyperspectral imaging device, wherein: include: An imaging system (141) is used to obtain a two-dimensional plane image of the object (200) to be measured; The Michelson interference system (160) is a small Fourier transform spectrometer including a MEMS matrix micromirror (162), a plane mirror / single MEMS micromirror / array MEMS micromirror (163), which receives the optical signal of each sub-region of the two-dimensional plane image and generates an interference signal corresponding thereto; A single / array photoelectric detector (180) receives the interference light signal and converts it into an electrical signal, which is then processed in sequence by a back-end amplifier analog-to-digital conversion circuit and a digital processing unit, and then combined with the two-dimensional plane image processing to obtain a hyperspectral image cube of the object to be measured (200).

2. The hyperspectral imaging device according to claim 1, wherein: The imaging system (141) is a CMOS camera or a near-infrared camera, and is located between the beam processing unit and the Michelson interferometer system (160), or between the Michelson interferometer system (160) and a single / array photodetector (180).

3. The hyperspectral imaging device according to claim 1, wherein: The Michelson interferometer system (160) further comprises: A first beam splitter (161) receives the optical signal of each sub-region of the two-dimensional plane image and divides the optical signal into two paths. The MEMS matrix micromirror (162) receives part of the optical signal output by the first beam splitter (161), and reflects it back to the first beam splitter (161) after modulation; the plane mirror / single MEMS rotating micromirror / array MEMS rotating micromirror (163) receives another optical signal output by the first beam splitter (161) and reflects it back to the first beam splitter (161); the first beam splitter (161) receives the optical signal modulated by the MEMS matrix micromirror (162) and the optical signal reflected by the plane mirror / single MEMS rotating micromirror / array MEMS rotating micromirror (163), and combines them to form the interference signal of the corresponding area.

4. The hyperspectral imaging device according to claim 3, wherein: The light detector (180) is a single structure, the MEMS matrix micromirror (162) and the two-dimensional plane image are conjugate with each other, and the single photodetector (180) acquires spectral information of different regions of the object (200) under test at different times, and finally completes the entire image by splicing according to the order of data acquisition.

5. The hyperspectral imaging device according to claim 3, wherein: The photodetector (180) is of an array structure, the array photodetector (180) and the MEMS matrix micromirror (162) are conjugated with each other, and the array photodetector (180) array simultaneously acquires spectral information of different regions of the measured object (200) according to the MEMS matrix micromirror (162).

6. The hyperspectral imaging device according to claim 1, wherein: The MEMS matrix micromirror (162) is a vertical large displacement MEMS micromirror, and its driving mode is selected from at least one of electrothermal driving, electrostatic driving, electromagnetic driving, and piezoelectric driving, or a combination of driving modes.

7. The hyperspectral imaging device according to claim 2, wherein: The beam processing unit includes: A light source (121) directly illuminates the object to be measured (200); and The second beam splitter (130) splits the optical path of the measured object (200) into two paths, one of which is projected to the imaging system (141) and the other is projected to the Michelson interference system (160).

8. The hyperspectral imaging device according to claim 2, wherein: The beam processing unit includes: Light source (122); a third beam splitter (111) that reflects the light emitted by the light source (122) to the object to be measured (200), and the light is reflected by the object to be measured (200) to the second beam splitter (130); and The second beam splitter (130) splits the optical path of the measured object (200) into two paths, one of which is projected to the imaging system (141) and the other is projected to the Michelson interference system (160).

9. The hyperspectral imaging device according to claim 7 or 8, wherein: The light source (121 / 122) is a coaxial broadband light source or a paraxial broadband light source or ambient light.

10. The hyperspectral imaging device according to claim 1, wherein: The relationship between the number of arrays of the MEMS matrix micromirrors (162), the array MEMS rotating micromirrors (163), and the array photodetectors (180) is as follows: the number of arrays of the MEMS matrix micromirrors (162) is greater than or equal to the number of array MEMS rotating micromirrors (163), and the number of array photodetectors (180).

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