View field modulation hyperspectral imaging system based on simulation micromirror array

Abstract

The invention discloses a field-of-view modulation hyperspectral imaging system based on an analog micromirror array, and relates to the technical field of hyperspectral imaging, the system comprises an AMA field-of-view scanning system, a single-point spectrometer and a control module, the AMA field-of-view scanning system comprises a plurality of MEMS micromirror units capable of independently controlling deflection angles, the control module firstly obtains a scanning path comprising a plurality of scanning deflection angle parameter groups, wherein each scanning deflection angle parameter group comprises one or more coding groups; each coding group comprises the deflection angle of each MEMS micromirror unit; based on the scanning path, obtaining a driving signal of each coding group; spectral information under each driving signal sent by the single-point spectrometer is obtained; and finally, obtaining a hyperspectral image based on all the spectral information and the coding group corresponding to each piece of spectral information, and providing a hyperspectral imaging scheme with high resolution and high flexibility.

Description

Technical Field

[0001] This application relates to the field of hyperspectral imaging technology, and in particular to a field-modulated hyperspectral imaging system based on a simulated micromirror array. Background Technology

[0002] Hyperspectral imaging technology plays an irreplaceable role in many fields because it can simultaneously capture two-dimensional spatial information and one-dimensional spectral information of a target. However, traditional hyperspectral imaging technologies have inherent limitations: oscillating scanning systems are bulky, slow to scan, and have low scanning resolution; pushbroom and snapshot hyperspectral systems rely on platform movement, require expensive area array detectors, and have inherently narrow wavelength ranges.

[0003] In existing technologies, MEMS micromirror units have been attempted for hyperspectral imaging to replace bulky scanning mechanisms. However, most of these solutions only utilize the simple deflection scanning function of MEMS micromirror units, and their operating mode is essentially still a sequential acquisition "point-by-point" or "line-by-line". This "one-to-one" mapping acquisition fails to fully utilize the light field information, the data acquisition efficiency still needs to be improved, and the system flexibility is insufficient.

[0004] The rise of computational imaging technology has provided new solutions to these problems. Among them, active imaging technologies with programmable illumination, such as compressed sensing hyperspectral imaging based on digital micromirror devices (DMDs), can reconstruct a complete hyperspectral data cube from a small number of measurements by projecting a series of coded patterns onto the target, significantly improving light energy utilization and acquisition speed. However, DMD systems typically need to be combined with spectroscopic elements (such as gratings or filter wheels), and DMDs only provide single-field-of-view imaging. Changing the field of view still results in a complex system structure, and the spectral resolution and range are limited. Summary of the Invention

[0005] The purpose of this application is to provide a field-modulated hyperspectral imaging system based on a simulated micromirror array, which can provide a high-resolution and highly flexible hyperspectral imaging scheme.

[0006] To achieve the above objectives, this application provides the following solution: This application provides a field-modulated hyperspectral imaging system based on an analog micromirror array, including an AMA field-scanning system, a single-point spectrometer, and a control module.

[0007] The AMA field-of-view scanning system includes multiple MEMS micromirror units; each MEMS micromirror unit includes a mirror and one or more drive arms, the drive arms being used to drive the mirror to rotate to change the deflection angle of the mirror, the mirror being used to receive and reflect sample light; the sample light is light containing spectral information of the target object.

[0008] The single-point spectrometer is used to acquire the sample light reflected from each of the specular surfaces.

[0009] The control module is used for: The scanning path is obtained; the scanning path includes one or more scanning deflection angle parameter groups, each of the scanning deflection angle parameter groups includes one or more encoding groups; each encoding group includes the deflection angle of each MEMS micromirror unit; wherein, when there are multiple encoding groups, the scanning deflection angle parameter group includes a first encoding group and other encoding groups; when there is only one encoding group, the scanning deflection angle parameter group includes a first encoding group; in the first encoding group, all the MEMS micromirror units have the same deflection angle; in the other encoding groups, at least one MEMS micromirror unit has a deflection angle that is in an off state; the off state deflection angle enables the single-point spectrometer to not receive sample light emitted by the mirror surface of the corresponding MEMS micromirror unit.

[0010] Based on the scanning path, a driving signal is obtained for each of the coded groups; the driving signal is used to control the driving arm to drive the mirror to rotate.

[0011] Acquire spectral information for each driving signal sent by the single-point spectrometer.

[0012] A hyperspectral image is obtained based on all the spectral information and the corresponding encoding group for each of the spectral information.

[0013] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a field-of-view modulation hyperspectral imaging system based on an analog micromirror array (AMA), including an AMA field-of-view scanning system, a single-point spectrometer, and a control module. The AMA field-of-view scanning system includes multiple MEMS micromirror units. Each MEMS micromirror unit includes a mirror and multiple driving arms. The driving arms drive the mirror to rotate, changing its deflection angle. The mirror receives and reflects sample light. The sample light contains spectral information of the target object. The single-point spectrometer acquires the spectral information of the sample light reflected by each mirror. When the driving arms change the deflection angle of the mirror in the MEMS micromirror unit, the position of the target object corresponding to the sample light received by the mirror also changes. Therefore, mirrors with different deflection angles correspond to different fields of view. By controlling the driving arms, modulation of different fields of view can be achieved. During operation, the control module first acquires the scanning path, and then... The scanning path obtains the driving signal for each coding group and finally acquires the spectral information under each driving signal. The scanning path includes one or more scanning deflection angle parameter groups, each of which includes one or more coding groups. Each coding group includes the deflection angle of each MEMS micromirror unit. When there are multiple coding groups, the scanning deflection angle parameter group includes a first coding group and other coding groups. When there is only one coding group, the scanning deflection angle parameter group includes a first coding group. In the first coding group, all MEMS micromirror units have the same deflection angle. In the other coding groups, at least one MEMS micromirror unit has a deflection angle that is in the off state. This means that each field of view can correspond to multiple different spectral information codes. By using multiple spectral information codes corresponding to multiple codes, the spatial resolution of the field of view is improved. Therefore, this invention provides a high-resolution and highly flexible hyperspectral imaging scheme. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of a field-of-view modulation hyperspectral imaging system based on a simulated micromirror array according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of an AMA field-of-view scanning system provided in one embodiment of this application; Figure 2 (a) in the figure is a schematic diagram of the initial state of all MEMS micromirror units when no driving signal is applied; Figure 2(b) is a schematic diagram showing the state when all MEMS micromirror units deflect at the same angle when a first driving signal corresponding to a certain first coding group is applied. Figure 2 (c) in the figure is a schematic diagram of applying different first driving signals and second driving signals to different micromirror units at the same time to achieve different deflection angle states. Figure 3 Images taken with an electron microscope Figure 2 A structural diagram of a single MEMS micromirror unit; Figure 4 This is a schematic diagram of the scanning method corresponding to the scanning path provided in one embodiment of this application; Figure 4 (a) in the diagram is a schematic diagram of a one-dimensional linear scan method; Figure 4 (b) in the diagram is a schematic diagram of a two-dimensional raster scanning method; Figure 4 (c) in the diagram is a schematic of the scanning method for arbitrary path scanning; Figure 5 A schematic diagram illustrating three encoding methods provided in one embodiment of this application; Figure 5 (a) in the diagram is a schematic diagram of the encoding method for sequentially closing a single MEMS micromirror unit; Figure 5 (b) is a schematic diagram of the encoding method for sequentially closing multiple adjacent MEMS micromirror units; Figure 5 (c) in the figure is a schematic diagram of the encoding method for the deflection angle of multiple non-adjacent MEMS micromirror units. Figure 6 This is a schematic diagram of the structure and working optical path of a Fourier transform spectrometer; Figure 7 This is a schematic diagram of a field-modulated hyperspectral imaging system based on a simulated micromirror array, provided as another embodiment of this application.

[0016] Figure reference numerals: 1 drive arm, 2 mirror, 3 substrate. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Those skilled in the art will recognize that embodiments of the present invention can be implemented as a system, apparatus, device, method, or computer program product. Therefore, the present invention can be specifically implemented in the following forms: entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0020] It should be noted that the number of any elements in the accompanying drawings is for illustrative purposes only and not as a limitation, and any naming is for distinction only and has no limiting meaning.

[0021] Explanation of technical terms: MEMS: Micro-Electro-Mechanical System.

[0022] MEMS micromirror unit: A micromirror unit manufactured based on microelectromechanical systems (MEMS) technology.

[0023] AMA (Analog Micromirror Array): Analog micromirror array.

[0024] AMA field-of-view scanning system: A field-of-view scanning system based on analog micromirror array (AMA).

[0025] In one exemplary embodiment, such as Figure 1 As shown, a field-of-view modulation hyperspectral imaging system based on an analog micromirror array is provided. The field-of-view modulation hyperspectral imaging system based on an analog micromirror array includes an AMA field-of-view scanning system, a single-point spectrometer, and a control module.

[0026] The AMA field-of-view scanning system includes multiple MEMS micromirror units; each MEMS micromirror unit includes a mirror and multiple driving arms, the driving arms being used to drive the mirror to rotate to change the deflection angle of the mirror, the mirror being used to receive and reflect sample light; the sample light is light containing spectral information of the target object.

[0027] The single-point spectrometer is used to acquire the spectral information of the sample light reflected from each of the specular surfaces.

[0028] The control module is used for: The scanning path is obtained; the scanning path includes one or more scanning deflection angle parameter groups, each of the scanning deflection angle parameter groups includes one or more encoding groups; each encoding group includes the deflection angle of each MEMS micromirror unit; wherein, when there are multiple encoding groups, the scanning deflection angle parameter group includes a first encoding group and other encoding groups; when there is only one encoding group, the scanning deflection angle parameter group includes a first encoding group; in the first encoding group, all the MEMS micromirror units have the same deflection angle; in the other encoding groups, at least one MEMS micromirror unit has a deflection angle that is in an off state; the off state deflection angle enables the single-point spectrometer to not receive sample light emitted by the mirror surface of the corresponding MEMS micromirror unit.

[0029] Based on the scanning path, a driving signal is obtained for each of the coded groups; the driving signal is used to control the driving arm to drive the mirror to rotate.

[0030] Acquire spectral information for each driving signal sent by the single-point spectrometer.

[0031] A hyperspectral image is obtained based on all the spectral information and the corresponding encoding group for each of the spectral information.

[0032] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided, wherein the deflection angle includes a deflection angle in a first direction and a deflection angle in a second direction; the first direction refers to the direction in which the mirror rotates about a first axis; the second direction is the direction in which the mirror rotates about a second axis; the first axis and the second axis are both straight lines in the plane where the mirror is located, and they are perpendicular to each other.

[0033] In one exemplary embodiment, a schematic diagram of an AMA field-of-view scanning system is provided. The AMA field-of-view scanning system consists of multiple MEMS micromirror units arranged in an array. Figure 2 As shown, Figure 2 (a) in the figure is a schematic diagram of the initial state of all MEMS micromirror units when no driving signal is applied; Figure 2 (b) is a schematic diagram showing the state when all MEMS micromirror units deflect at the same angle when a first driving signal corresponding to a certain first coding group is applied. Figure 2 (c) in the figure is a schematic diagram of applying different first driving signals and second driving signals to different micromirror units at the same time to achieve different deflection angle states.

[0034] like Figure 3 The image shown is taken with an electron microscope. Figure 2The diagram shows the structure of a single MEMS micromirror unit. Each MEMS micromirror unit includes four drive arms 1, a mirror 2, and a substrate 3. The mirror 2 is square or rectangular. One end of each of the four drive arms 1 is connected to the midpoint of the four sides of the bottom surface of the mirror 2, and the other end of each drive arm 1 is connected to the substrate.

[0035] Each drive arm 1 is electrically connected to the control module to receive control signals (e.g., drive signals) from the control module. These control signals can control the extension and retraction length of the drive arm 1. By controlling the length of the drive arm 1, the mirror 2 is driven to rotate, thereby changing the deflection angle of the mirror 2. In some embodiments, the substrate 3 is disposed on a PCB circuit board to facilitate the arrangement of electrical connection lines between each drive arm 1 and the control module.

[0036] For example, the first, second, third, and fourth sides of mirror 2 are respectively connected to the first, second, third, and fourth drive arms. The first side is adjacent to the second side, the second side is adjacent to the third side, the third side is adjacent to the fourth side, and the first side is adjacent to the fourth side. The length changes of the first and third drive arms control the rotation of mirror 2 around the first axis, and the length changes of the second and fourth drive arms control the rotation of mirror 2 around the second axis. Both the first and second axes are straight lines on the plane where mirror 2 is located, and the first and second axes are perpendicular to each other.

[0037] In some embodiments, the MEMS micromirror unit may also contain only two drive arms, which are respectively arranged on two adjacent sides, and can also realize the function of rotating the mirror surface around two vertical axes to change the deflection angle in two directions.

[0038] In some embodiments, the MEMS micromirror unit may also contain only one drive arm, in which case the mirror surface can only be deflected in one direction.

[0039] In any of the above embodiments, the optical path between the single-point spectrometer and the AMA field-of-view scanning system is fixed. Since the single-point spectrometer has a limited area for receiving light, only the deflection angle of the MEMS micromirror unit within the viewing angle range (1~Px, 1~Py) of the single-point spectrometer can reflect sample light back to the spectrometer. Here, 1~Px refers to the range of deflection angles of the MEMS micromirror unit relative to its initial position in the first direction, and 1~Py refers to the range of deflection angles of the MEMS micromirror unit relative to its initial position in the second direction. The deflection angles of the MEMS micromirror units in the first coding group are all within the viewing angle range.

[0040] When the deflection angle of a MEMS micromirror unit exceeds the viewing angle range, the single-point spectrometer will not receive the sample light reflected by that MEMS micromirror unit, and in this case, the MEMS micromirror unit is considered to be in the off state. Conversely, when the deflection angle of a MEMS micromirror unit is within the viewing angle range, the single-point spectrometer can receive the sample light reflected by that MEMS micromirror unit, and in this case, the MEMS micromirror unit is considered to be in the on state. The deflection angle of the MEMS micromirror units can be controlled by the control signal applied to the drive arm by the control module, thereby controlling the on / off state of each MEMS micromirror unit. Any deflection angle outside the viewing angle range can be specified as the off state deflection angle, for example, (0,0) can be used as the off state deflection angle.

[0041] In the above scheme, when the deflection angle of the mirror of the MEMS micromirror unit changes due to the driving arm, the position of the target object corresponding to the sample light received by the mirror also changes accordingly. Therefore, mirrors with different deflection angles correspond to different fields of view. By controlling the driving arm, modulation of different fields of view can be achieved. During operation, the control module first obtains the scanning path, then obtains the driving signal for each coded group based on the scanning path, and finally obtains the spectral information under each driving signal. The scanning path includes one or more scanning deflection angle parameter groups, and each scanning deflection angle parameter group includes one or more coded groups. Each coded group includes the deflection angle of each MEMS micromirror unit. When there are multiple coded groups, the scanning deflection angle parameter group includes a first coded group and other coded groups. When there is only one coded group, the scanning deflection angle parameter group includes a first coded group. In the first coded group, all MEMS micromirror units have the same deflection angle. In the other coding groups, at least one MEMS micromirror unit has a deflection angle that is in the off state. This off-state deflection angle ensures that the single-point spectrometer does not receive sample light emitted from the mirror surface of the corresponding MEMS micromirror unit. This means that each field of view can correspond to multiple different spectral information codes. By using multiple spectral information codes, the spatial resolution of the field of view is improved. Furthermore, this solution can use a single-point spectrometer, whose core detector is composed of single-point detectors. Compared with linear or area array detectors, single-point detectors have the advantages of low cost and easy wider band detection. Traditional snapshot or line scan spectrometers use area array detectors, which cannot use single-point detectors. At the same time, the scanning path of this invention can be based on user-defined methods, thus overcoming the limitations of insufficient flexibility in sequential acquisition methods. Therefore, this invention provides a low-cost, high-resolution, wide-band, and highly flexible hyperspectral imaging solution.

[0042] In the field-modulated hyperspectral imaging system based on an analog micromirror array (AMA), the AMA field-of-view scanning system is a microelectromechanical system (MEMS). Each MEMS micromirror unit is capable of one-dimensional and two-dimensional analog deflection and scanning each unit of the micromirror array at a large angle, ensuring that reflected sample light cannot enter the single-point spectrometer, thus achieving a digital "on / off" state. The AMA field-of-view scanning system actively simulates beam deflection by receiving drive signals from the control module, thereby achieving non-mechanical field-of-view scanning. This active digital beam deflection achieves DMD-like beam modulation.

[0043] In some embodiments, the viewing angle range of the single-point spectrometer is (1~Px, 1~Py). The deflection angle resolution of each MEMS micromirror unit in the AMA field-of-view scanning system is 1. That is, in the first direction, the deflection angle range of the MEMS micromirror unit is 1~Px (in all embodiments, the unit of deflection angle is degrees by default), and in the second direction, when the deflection angle range of the MEMS micromirror unit is 1~Py, the sample light reflected by it can enter the single-point spectrometer. At this time, there are Px×Py fields of view. Under each field of view, all micromirrors have the same deflection angle and are within the viewing angle range of the single-point spectrometer. By adjusting the position and angle relationship between the single-point spectrometer, the AMA field-of-view scanning system, and the target object, the correspondence between each field of view and the object point position of the target object can be obtained. The adjusted system can obtain the spectral information of the object points corresponding to Px×Py fields of view. At this time, the number of object points is Px×Py.

[0044] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided. When the scan deflection angle parameter set includes a first encoding group, the control module is used for: The scanning method is determined; the scanning method is one of one-dimensional linear scanning, two-dimensional raster scanning, and arbitrary path scanning.

[0045] Based on the scanning method, the number of groups of scanning deflection angle parameters and the first encoding group of each scanning deflection angle parameter group are obtained.

[0046] The scan path can be obtained based on the specific scanning method, such as Figure 4 The diagram shows three scanning methods. Figure 4 (a) shows a schematic diagram of a one-dimensional linear scan method; Figure 4 (b) shows a schematic diagram of a two-dimensional raster scanning method; Figure 4 (c) shows a schematic diagram of an arbitrary path scanning method. The scanning method can be pre-stored in the control module, or a customer-defined method can be achieved by reprogramming the internal program of the control module to flexibly modulate the field of view.

[0047] Figure 4 In the figure, there are n×n object points, and the corresponding viewing angle range of the single-point spectrometer is (1~n, 1~n).

[0048] One-dimensional linear scanning refers to sequentially scanning a series of points on a target object in a certain direction. For example, the first row of points is scanned sequentially. The second direction angle of the mirror corresponding to the first row of points is 1. The n points from left to right correspond to the deflection angle range of the first direction in the field of view of the single-point spectrometer. There are a total of n deflection angle parameter groups. The deflection angles of the first coding group are (1,1), (2,1), (3,1)......(n,1). In this way, the spectral information corresponding to the n fields of view of all MEMS micromirror units with deflection angles of (1,1), (2,1), (3,1)......(n,1) can be obtained.

[0049] Two-dimensional raster scanning refers to scanning all points of a target object sequentially, line by line. Here, "all points" refers to all points corresponding to the viewing angle range of a single-point spectrometer.

[0050] During operation, all object points in the first row are scanned first, then all object points in the second row are scanned, then all object points in the third row are scanned, and so on, until all object points in the nth row are scanned. The scanning of all object points in each row is similar to a one-dimensional linear scan. For example, when scanning all object points in the mth row, the deflection angles of the first coding group corresponding to the deflection angle parameter group are (1, m), (2, m), (3, m) ... (n, m) in sequence. In this way, the spectral information corresponding to the n fields of view of all MEMS micromirror units with deflection angles of (1, m), (2, m), (3, m) ... (n, m) can be obtained.

[0051] Arbitrary path scanning refers to scanning any number of points of the target object by specifying several sets of scanning deflection angle parameters.

[0052] In practical applications, arbitrary path scanning can achieve precise scanning of regions of interest while skipping scanning unimportant areas, thereby improving the overall scanning speed. For example, after screening a large number of lesions in biological tissues, the focus can be on scanning the spectral imaging of the area near the lesions.

[0053] Preferably, for any scanning deflection angle parameter group in any of the above embodiments, an encoding group can be added to improve the hyperspectral resolution of the target object point in the field of view corresponding to the scanning deflection angle parameter group.

[0054] The encoding group settings can be configured using a preset encoding template or a user-defined encoding method.

[0055] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided. When the scan deflection angle parameter set includes a first encoding group and other encoding groups, the control module is used for: The scanning method is determined; the scanning method is one of one-dimensional linear scanning, two-dimensional raster scanning, and arbitrary path scanning.

[0056] Based on the scanning method, the number of groups of scanning deflection angle parameters and the first encoding group of each scanning deflection angle parameter group are obtained.

[0057] Obtain the encoding method; the encoding method is one of the following: sequentially shutting down a single MEMS micromirror unit, sequentially shutting down multiple adjacent MEMS micromirror units, and sequentially shutting down multiple non-adjacent MEMS micromirror units.

[0058] Based on the encoding method, other encoding groups are determined for each of the scan deflection angle parameter groups.

[0059] The scanning method is the same as in the previous embodiment, and will not be described again here.

[0060] like Figure 5 The diagram shown illustrates three encoding methods (which can be configured as encoding templates).

[0061] Figure 5 (a) in the diagram is a schematic diagram of the encoding method in which a single MEMS micromirror unit is turned off sequentially. This encoding method is the highest resolution encoding method. For example, the AMA field-of-view scanning system includes MEMS micromirror units arranged in an array of k rows × k columns. This encoding method includes k × k encoding groups. The a-th encoding is: the deflection angle of the MEMS micromirror unit in the b-th row and c-th column is the deflection angle in the off state, a = (b-1) × k + c, where a, b, c and k are all integers.

[0062] Figure 5 (b) is a schematic diagram of the encoding method for sequentially closing multiple adjacent MEMS micromirror units. For example, the AMA field-of-view scanning system includes MEMS micromirror units arranged in an array of k rows × k columns. This encoding group includes k × k / d (assuming to be an integer) encoding methods, where d is the number of adjacent MEMS micromirror units that are closed each time. The a-th encoding is: starting from the MEMS micromirror unit in the b-th row and c-th column, the deflection angle of the consecutive d MEMS micromirror units is the deflection angle of the off state, 1 + (a-1) × d = (b-1) × k + c, where a, b, c, d and k are all integers.

[0063] Figure 5(c) in the diagram is a schematic diagram of the encoding method for sequentially closing multiple non-adjacent MEMS micromirror units, which can be customized by the user according to their needs.

[0064] It should be noted that the above encoding method refers to the digital modulation process under a fixed field of view, which is one of the main technologies of this invention for improving spectral spatial resolution. The AMA field-of-view scanning system consists of multiple independently controllable MEMS micromirror units and is the core spatial light modulation component of this system. It can be controlled by a drive signal to enter the "on" state, reflecting the sample light into the receiving range of the single-point spectrometer, or to enter the "off" state, reflecting the sample light outside the receiving range of the single-point spectrometer.

[0065] The coding methods corresponding to digital modulation under a fixed field of view include, but are not limited to, a single micromirror unit sequentially realizing the switching state of a single micromirror from top to bottom and from left to right; multiple consecutive micromirror units sequentially realizing the switching state of multiple micromirror units from top to bottom and from left to right; multiple non-consecutive micromirror units sequentially realizing the switching state of multiple micromirror units from top to bottom and from left to right; and realizing the switching state of multiple micromirror units based on coding methods such as Hadamard matrix and Fourier matrix.

[0066] In the above embodiments, the system achieves active imaging through flexible scanning paths and coding modulation methods, and the signal-to-noise ratio is improved compared with the point-by-point scanning system under the same acquisition time and illumination conditions.

[0067] In one exemplary embodiment, a field-modulated hyperspectral imaging system based on an analog micromirror array is provided, which also includes a lens group and an optical coupling interface.

[0068] The lens group is used to calibrate the sample light reflected from the mirror to obtain calibrated sample light.

[0069] The optical coupling interface is used to optically couple the calibrated sample to the single-point spectrometer.

[0070] Preferably, the coupling method of the optical coupling interface is an optical fiber interface or a space optical interface.

[0071] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on an analog micromirror array is provided. When the scan deflection angle parameter set includes a first encoding group, the control module is configured to: obtain the driving signal for each encoding group based on the scan path. Based on the first coding group, a first driving signal is generated for each MEMS micromirror unit; the first driving signal of each MEMS micromirror unit can drive the driving arm of the corresponding MEMS micromirror unit so that all mirrors reach and maintain the same deflection angle.

[0072] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on an analog micromirror array is provided. When the scan deflection angle parameter set includes a first coding group and other coding groups, the control module is configured to: obtain the drive signal for each coding group based on the scan path. Based on the first coding group, a first driving signal is generated for each MEMS micromirror unit; the first driving signal of each MEMS micromirror unit can drive the driving arm of the corresponding MEMS micromirror unit so that all mirrors reach and maintain the same deflection angle.

[0073] Based on the other coding groups, a second driving signal is generated for the corresponding MEMS micromirror unit; the second driving signal can control the driving arm corresponding to the MEMS micromirror unit so that the deflection angle of the mirror is the off-state deflection angle.

[0074] The first drive signal has a higher priority than the second drive signal.

[0075] Preferably, the second driving signal is applied at the same time as the first driving signal is applied, and the first driving signal is reapplied before each application of the second driving signal corresponding to a different coding group, or the previous second driving signal is canceled.

[0076] In one exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided. The scanning path is obtained based on a two-dimensional grating scanning method, and no other coding groups are configured for all the scanning deflection angle parameter groups in the scanning path.

[0077] The single-point spectrometer has a viewing angle range of (1~n, 1~n), and the deflection angle resolution of each MEMS micromirror unit is 1. The system can acquire the spectral information of n rows × n columns of object points. Each object point corresponds to a scanning field of view, and each scanning field of view corresponds to a scanning deflection angle parameter group. Each scanning deflection angle parameter group has a first coding group. The object points in the first row correspond to the scanning deflection angle parameter groups of n scanning fields of view, and the deflection angles of the first coding groups corresponding to them are (1,1), (2,1), (3,1)......(n,1) in sequence. The object points in the second row correspond to the scanning deflection angle parameter groups of n scanning fields of view, and the deflection angles of the first coding groups corresponding to them are (1,2), (2,2), (3,2)......(n,2) in sequence. And so on, the scanning deflection angle parameter groups of n×n scanning fields of view corresponding to all object points in the n rows are obtained, and n×n first driving signals are obtained in sequence.

[0078] The control module sequentially applies n×n first drive signals to the AMA field-of-view scanning system and acquires the spectral information under each first drive signal. The spectral information of the n scanning fields corresponding to the object point in the first row is B. 1,1 B 2,1 B 3,1 ......B n,1 The spectral images corresponding to these spectral information are, in order, S(1, 1, B). 1,1 S(2,1,B) 2,1 S(3,1,B) 3,1 )......S(n,1,B n,1 The spectral information of the n scanning fields corresponding to the object point in the second row is B, in order. 1,2 B 2,2 B 3,2 ......B n,2 The spectral images corresponding to these spectral information are, in order, S(1, 2, B). 1,2 S(2,2,B) 2,2 S(3,2,B) 3,2 )......S(n,2,B) n,2 ); and so on, the spectral information of the n scanning fields corresponding to the object point in the nth row is B in sequence. 1,n B 2,n B 3,n ......B n,n The spectral images corresponding to these spectral information are, in order, S(1, n, B). 1,n S(2, n, B) 2,n S(3, n, B) 3,n )......S(n, n, B n,n All spectral images are stitched together to create a 3D hyperspectral image.

[0079] In an exemplary embodiment, based on the previous embodiment, other coding groups under each scanning deflection angle parameter group are obtained based on the coding method of sequentially shutting down individual MEMS micromirror units. The AMA field-of-view scanning system includes MEMS micromirror units arranged in an array of k rows × k columns. In this case, under the fixed field of view corresponding to each object point, k × k coding groups are added, corresponding to k × k second driving signals. Each second driving signal controls the shutdown of a MEMS micromirror unit individually (for example, controlling the deflection angle of the MEMS micromirror unit in any direction to be 0, so that the sample light reflected by it cannot enter the single-point spectrometer).

[0080] For example, in the scanning deflection angle parameter group of the scanning field of view corresponding to the first object point in the first row, the deflection angle of the first coding group is (1, 1), and the corresponding first driving signal is U1. Under the first driving signal U1, all MEMS micromirror units deflect at an angle of (1, 1) to obtain spectral information B. 1，1 .

[0081] Based on the applied first driving signal U1, a second driving signal V1 is applied to the MEMS micromirror unit in the first row and first column, so that the deflection angle of the MEMS micromirror unit in the first row and first column is the off-state deflection angle, and the spectral information C is obtained. 1,1 At this point, the spatial spectral information D corresponding to the MEMS micromirror unit in the first row and first column is... 1,1 =B 1,1 -C 1,1 Then, based on the first driving signal U1 (without applying the second driving signal V1), the second driving signal V2 is applied to the MEMS micromirror unit in the first row and second column, so that the deflection angle of the MEMS micromirror unit in the first row and second column is the off-state deflection angle, and the spectral information C is obtained. 1,2 At this point, the spatial spectral information D corresponding to the MEMS micromirror unit in the 1st row and 2nd column is... 1,2 =B 1,2 -C 1,2 Similarly, during the control process of k×k second driving signals, k×k spatial spectral information of the first object point is obtained. In this way, by applying k×k corresponding second driving signals in sequence under each first driving signal, k×k spectral information of each object point corresponding to n×n object points will be obtained, which is equivalent to improving the spatial resolution by k×k times.

[0082] In one exemplary embodiment, a field-of-view modulation hyperspectral imaging system based on a simulated micromirror array is provided. The driving arm is driven by one of the following methods: electrothermal driving, electromagnetic driving, piezoelectric driving, and electrostatic driving. For example, in an electrothermal driving system, the driving arm deforms due to heat accumulation and dissipation under voltage, thereby causing the mirror surface of the MEMS micromirror unit to deflect or move vertically up and down.

[0083] Preferably, each MEMS micromirror unit is equipped with a displacement feedback structure, such as a piezoresistive sensor or a capacitive displacement detector. These sensors can monitor the deflection angle and displacement of the micromirror unit in real time and feed this data back to the control module for precise control.

[0084] In one exemplary embodiment, a field-of-view modulation hyperspectral imaging system based on an analog micromirror array is provided, wherein the single-point spectrometer is one of a grating spectrometer, an adjustable filter spectrometer, a computational reconstruction spectrometer, and a Fourier transform spectrometer.

[0085] Preferably, such as Figure 6 and Figure 7 As shown, Figure 6 This is a schematic diagram of the structure and working optical path of a Fourier transform spectrometer. Figure 7 This is a schematic diagram of a field-modulated hyperspectral imaging system based on a simulated micromirror array when a Fourier transform spectrometer is used as a single-point spectrometer.

[0086] The Fourier transform spectrometer includes a laser, a fixed mirror, a moving mirror, a focusing lens, two dichroic mirrors, and two single-point detectors. The laser provides reference light to accurately measure the displacement of the moving mirror. The fixed mirror and the moving mirror form a beam-splitting interference system. One dichroic mirror splits the sample light into transmission and reflection paths according to wavelength to achieve band selection, and the other dichroic mirror separates the light path to the two single-point detectors to achieve dual-channel detection.

[0087] When the single-point spectrometer is a Fourier transform spectrometer, the control module is further configured to: acquire spectral information under each driving signal sent by the single-point spectrometer. After applying each driving signal and before acquiring the spectral information, the position of the moving mirror is controlled to adjust the optical path difference between the sample light and the reference light. Through the Michelson interferometer platform formed by the moving mirror and the fixed mirror, the two detectors synchronously receive the laser and sample interference signals during the movement of the moving mirror. The moving mirror position information is acquired in real time through the laser interference signal, and the sample light information under equal spatial path is obtained by equal phase interpolation through the laser interference signal. Then, the spectral information is formed by using fast Fourier transform technology. Fourier transform spectrometers have advantages such as low cost and wide band range when using a single-point detector. At the same time, the use of a moving mirror with a large vertical displacement can obtain higher resolution, thereby improving the wavelength resolution capability of hyperspectral spectrum.

[0088] In one exemplary embodiment, a field-modulated hyperspectral imaging system based on an analog micromirror array is provided, wherein the mirrors are square, circular, or hexagonal in shape.

[0089] In one exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided, wherein the spectral information includes: the intensity spectrum, reflectance spectrum, absorbance spectrum, and transmittance spectrum of the substance.

[0090] In an exemplary embodiment, a field-modulated hyperspectral imaging system based on a simulated micromirror array is provided. Regarding obtaining a hyperspectral image based on all the spectral information and the corresponding encoding group for each of the spectral information, the control module is configured to: When the coding group does not contain other coding groups, for any first spectral information, the first spectral information is mapped based on the coding group corresponding to the first spectral information to obtain the mapped spectral information; the first spectral information is the spectral information corresponding to any first coding group.

[0091] A hyperspectral image is obtained based on the mapped spectral information.

[0092] When the coding group contains other coding groups, for any first spectral information, the first spectral information is mapped based on the coding group corresponding to the first spectral information to obtain the mapped spectral information; the first spectral information is the spectral information corresponding to any first coding group.

[0093] For any second spectral information, based on the coding group corresponding to the second spectral information, the second spectral information is encoded and decoded to obtain the third spectral information, and a hyperspectral image is obtained based on the third spectral information and the mapped spectral information; the second spectral information is the spectral information corresponding to any of the other coding groups.

[0094] As an optional implementation, inverse coding refers to calculating the spectral information of the spatial region mapped by the MEMS micromirror unit whose deflection angle is the off-state deflection angle.

[0095] For example, in the scanning deflection angle parameter group of the scanning field of view corresponding to the first object point in the first row, the deflection angle of the first coding group is (1, 1), and the corresponding first driving signal is U1. Under the first driving signal U1, all MEMS micromirror units deflect at an angle of (1, 1) to obtain spectral information B. 1，1 (i.e., the first spectral information), the mapped spectral information B 1，1 The spatial position corresponding to the first object point.

[0096] Based on the applied first driving signal U1, a second driving signal V1 is applied to the MEMS micromirror unit in the first row and first column, so that the deflection angle of the MEMS micromirror unit in the first row and first column is the off-state deflection angle, and the spectral information C is obtained. 1,1 (That is, the second spectral information), at this time, the spatial spectral information D corresponding to the MEMS micromirror unit in the first row and first column. 1,1 =B 1,1 -C 1,1(That is, the third spectral information); then, based on the first driving signal U1 (without applying the second driving signal V1), the second driving signal V2 is applied to the MEMS micromirror unit in the first row and second column, so that the deflection angle of the MEMS micromirror unit in the first row and second column is the off-state deflection angle, and the spectral information C is obtained. 1,2 At this point, the spatial spectral information D corresponding to the MEMS micromirror unit in the 1st row and 2nd column is... 1,2 =B 1,2 -C 1,2 (i.e., third spectral information); and so on, in the process of controlling k×k second driving signals, k×k spatial third spectral information at the first object point is obtained.

[0097] By replacing the spectral information corresponding to the spatial location in the original first spectral information with the third spectral information, the spectral information of k×k spatial points corresponding to the object point can be obtained, which is equivalent to improving the spatial resolution by a factor of k×k.

[0098] Finally, all the spectral information that has been mapped and decoded constitutes a hyperspectral image.

[0099] The above embodiments of the present invention have the following beneficial effects: 1. By adopting the AMA field-of-view scanning system, the analog deflection and digital modulation deflection of the beam are realized, which effectively solves the problems of "slow scanning" and "low resolution" of the traditional system. The spatial resolution can be improved by k×k times on the basis of scanning, where k×k is the number of MEMS micromirror array units in the AMA field-of-view scanning system.

[0100] 2. By using MEMS micromirror units as deflection components, the macroscopic mechanical scanning mechanism is eliminated, making the system compact, highly stable, low in power consumption, and easy to integrate, providing a hardware foundation for realizing portable hyperspectral imaging in real time on site.

[0101] 3. Seamless switching between multiple operating modes: Resolution Enhancement Mode: Improves the spatial resolution of global and local spectral imaging. Random Access Mode: Directly controls the micromirror array, performing hyperspectral acquisition only on specific pixels of interest. Traditional Scanning Mode: Performs point-by-point two-dimensional scanning, improving system flexibility and intelligence.

[0102] 4. Single-point spectrometers use linear arrays or single-point detectors, which have the advantages of wide band range and low cost, greatly improving the range of measurable substances.

[0103] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A field-modulated hyperspectral imaging system based on a simulated micromirror array, characterized in that, The field-of-view modulation hyperspectral imaging system based on analog micromirror array includes an AMA field-of-view scanning system, a single-point spectrometer, and a control module. The AMA field-of-view scanning system includes multiple MEMS micromirror units; each MEMS micromirror unit includes a mirror and one or more driving arms, the driving arms being used to drive the mirror to rotate to change the deflection angle of the mirror, the mirror being used to receive and reflect sample light; the sample light is light containing spectral information of the target object; The single-point spectrometer is used to acquire the sample light reflected from each of the specular surfaces; The control module is used to acquire a scanning path; the scanning path includes one or more scanning deflection angle parameter groups, each of the scanning deflection angle parameter groups includes one or more encoding groups; each encoding group includes the deflection angle of each MEMS micromirror unit; wherein, when there are multiple encoding groups, the scanning deflection angle parameter group includes a first encoding group and other encoding groups; when there is only one encoding group, the scanning deflection angle parameter group includes a first encoding group; in the first encoding group, all the MEMS micromirror units have the same deflection angle; in the other encoding groups, at least one MEMS micromirror unit has a deflection angle that is in an off state; the off state deflection angle enables the single-point spectrometer to not receive sample light emitted by the mirror surface of the corresponding MEMS micromirror unit; Based on the scanning path, a driving signal is obtained for each of the coded groups; the driving signal is used to control the driving arm to drive the mirror to rotate. Acquire spectral information under each driving signal sent by the single-point spectrometer; A hyperspectral image is obtained based on all the spectral information and the corresponding encoding group for each of the spectral information.

2. The field-of-view modulation hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, It also includes a lens assembly and an optical coupling interface; The lens group is used to calibrate the sample light reflected from the mirror to obtain calibrated sample light; The optical coupling interface is used to optically couple the calibrated sample to the single-point spectrometer.

3. The field-of-view modulation hyperspectral imaging system based on a simulated micromirror array according to claim 2, characterized in that, The optical coupling interface is coupled using either an optical fiber interface or a space optical interface.

4. The field-of-view modulation hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, The deflection angle includes a deflection angle in a first direction and a deflection angle in a second direction; the first direction refers to the direction in which the mirror rotates about a first axis; the second direction is the direction in which the mirror rotates about a second axis; the first axis and the second axis are both straight lines in the plane where the mirror is located, and the first axis and the second axis are perpendicular to each other.

5. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, When the scan deflection angle parameter group includes the first encoding group, the control module is used for: In acquiring the scan path, The scanning method is determined; the scanning method is one of one-dimensional linear scanning, two-dimensional raster scanning, and arbitrary path scanning. Based on the scanning method, the number of groups of scanning deflection angle parameters and the first encoding group of each scanning deflection angle parameter group are obtained.

6. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, When the scan deflection angle parameter group includes a first encoding group and other encoding groups, the control module is used for: In acquiring the scan path, The scanning method is determined; the scanning method is one of one-dimensional linear scanning, two-dimensional raster scanning, and arbitrary path scanning. Based on the scanning method, the number of groups of scanning deflection angle parameters and the first encoding group of each scanning deflection angle parameter group are obtained; Obtain the encoding method; the encoding method is one of the following: sequentially closing a single MEMS micromirror unit, sequentially closing multiple adjacent MEMS micromirror units, and sequentially closing multiple non-adjacent MEMS micromirror units; Based on the encoding method, other encoding groups are determined for each of the scan deflection angle parameter groups.

7. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, When the scan deflection angle parameter group includes a first encoding group and other encoding groups, the control module is used to obtain the drive signal for each encoding group based on the scan path, in terms of: Based on the first coding group, a first driving signal is generated for each MEMS micromirror unit; the first driving signal of each MEMS micromirror unit can drive the driving arm of the corresponding MEMS micromirror unit so that all mirrors reach and maintain the same deflection angle. Based on the other coding groups, a second driving signal is generated for the corresponding MEMS micromirror unit; the second driving signal can control the driving arm of the corresponding MEMS micromirror unit so that the deflection angle of the mirror is the off state deflection angle. The first drive signal has a higher priority than the second drive signal.

8. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, The driving method of the drive arm is one of electrothermal drive, electromagnetic drive, piezoelectric drive and electrostatic drive.

9. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, The single-point spectrometer is one of the following types: grating spectrometer, adjustable filter spectrometer, computational reconstruction spectrometer, and Fourier transform spectrometer.

10. The field-modulated hyperspectral imaging system based on a simulated micromirror array according to claim 1, characterized in that, In obtaining a hyperspectral image based on all the said spectral information and the corresponding encoding group for each of the said spectral information, the control module is configured to: When the coding group does not contain other coding groups, for any first spectral information, the first spectral information is mapped based on the coding group corresponding to the first spectral information to obtain the mapped spectral information; the first spectral information is the spectral information corresponding to any first coding group. A hyperspectral image is obtained based on the mapped spectral information; When the coding group contains other coding groups, for any first spectral information, the first spectral information is mapped based on the coding group corresponding to the first spectral information to obtain the mapped spectral information; the first spectral information is the spectral information corresponding to any first coding group. For any second spectral information, based on the coding group corresponding to the second spectral information, the second spectral information is encoded and decoded to obtain the third spectral information, and a hyperspectral image is obtained based on the third spectral information and the mapped spectral information; The second spectral information is the spectral information corresponding to any of the other coding groups.

Images