Spectral confocal measurement sensor and measurement method

Abstract

The invention provides a spectral confocal measurement sensor and a measurement method. The spectral confocal measurement sensor comprises a light source, a light splitting element, a scanning structure, a first focusing lens group, a diffraction grating, an image sensor and a data processor, the scanning structure can rotate to change the position of a measurement light beam, and the data processor is used for corresponding to wavelength information of a plurality of sub light beams according to pixel information of the image sensor. And calculating the position information of the object to be measured so as to obtain the surface information of the object to be measured. By arranging the scanning structure, the scanning structure can be controlled to rotate so as to change the position of the measurement light beam and realize rapid scanning on the to-be-measured surface of the to-be-measured object, so that traditional single-point or single-line measurement is expanded into surface measurement so as to obtain height information of each point of the to-be-measured surface and morphology information of the to-be-measured surface, and different measurement requirements can be met; and a measurement blind area is avoided, so that high-precision and high-efficiency surface measurement is realized.

Description

Technical Field

[0001] The present application belongs to the field of measurement technology, and specifically relates to a spectral confocal measurement sensor and a measurement method. Background Art

[0002] Traditional spectral confocal sensors can usually only perform single-point or single-line measurements, with a limited measurement range. It is difficult to quickly obtain surface morphology information over a large area, which cannot meet actual needs and affects production efficiency. If the sensor or the object being measured is moved multiple times to complete the task, it is not only cumbersome to operate, but also very easy to introduce errors from the displacement platform itself. In addition, the measurement time is long, and the subsequent data splicing algorithm is relatively complex and has low robustness, resulting in low measurement accuracy. Moreover, when facing surfaces with complex shapes and structures, traditional spectral confocal sensors are difficult to fully cover and measure, and are prone to measurement blind spots, further reducing the measurement accuracy. Summary of the Invention

[0003] In view of this, the first aspect of the present application provides a spectral confocal measurement sensor, the spectral confocal measurement sensor comprising: a light source, for outputting a measuring light beam; a beam splitter element for receiving and transmitting the measuring beam from the light source; a scanning structure for receiving the measuring beam from the beam splitter, wherein the scanning structure is rotatable to change the position of the measuring beam; a first focusing lens assembly, configured to receive and converge the measuring beam from the scanning structure, and direct the converged measuring beam toward the object to be measured; wherein the measuring beam is reflected by the object to be measured to form a feedback beam, the first focusing lens assembly is configured to receive the feedback beam from the object to be measured and convert it into parallel light, and direct the parallel feedback beam toward the scanning structure, which reflects the feedback beam toward the spectroscopic element; a diffraction grating, configured to receive the feedback beam reflected from the beam splitter, and further configured to decompose the feedback beam into a plurality of sub-beams with different wavelengths; an image sensor, configured to receive the plurality of sub-beams, wherein the plurality of sub-beams are respectively directed to different pixel positions of the image sensor; A data processor is electrically connected to the image sensor, and is used to correspond the wavelength information of the multiple sub-beams according to the pixel information of the image sensor, and calculate the position information of the object to be measured, thereby obtaining the surface information of the object to be measured.

[0004] Wherein, the spectral confocal measurement sensor meets the following conditions: Lx = |Lx2-Lx1| =f × |tan(Xβ1)-tan(Xβ0)| + f × |tan(Xβ2)-tan(Xβ0)|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measurement beam along the X-axis, Lx1 is the measurement size of the scanning structure along the X-axis when the scanning angle is Xβ1, Lx2 is the measurement size of the scanning structure along the X-axis when the scanning angle is Xβ2, f is the focal length of the first focusing lens group, Xβ is the scanning angle of the scanning structure, and Xβ0 represents the scanning angle of the scanning structure at the initial position, and Xβ1 and Xβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure; The spectral confocal measurement sensor also meets the following conditions: Ly = |Ly2-Ly1| = f × |tan(Yβ1)-tan(Yβ0)| + f × |tan(Yβ2)-tan(Yβ0)|, and 5≤f≤1000; Wherein, Ly is the measurement range of the measuring beam along the Y-axis, Ly1 is the measured dimension of the scanning structure along the Y-axis when the scanning angle is Yβ1, Ly2 is the measured dimension of the scanning structure along the Y-axis when the scanning angle is Yβ2, f is the focal length of the first focusing lens group, Yβ is the scanning angle of the scanning structure, and Yβ0 represents the scanning angle of the scanning structure at the initial position, and Yβ1 and Yβ2 represent scanning angles of the same size but opposite directions in the scanning structure.

[0005] Wherein, the spectral confocal measurement sensor meets the following conditions: Lx = |Lx2-Lx1| = f × |Xβ1-Xβ2|, Ly = |Ly2-Ly1| = f × |Yβ1-Yβ2|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measurement beam along the X-axis, Lx1 is the measurement dimension of the scanning structure along the X-axis when the scanning angle is Xβ1, Lx2 is the measurement dimension of the scanning structure along the X-axis when the scanning angle is Xβ2, Ly is the measurement range of the measurement beam along the Y-axis, Ly1 is the measurement dimension of the scanning structure along the Y-axis when the scanning angle is Yβ1, Ly2 is the measurement dimension of the scanning structure along the Y-axis when the scanning angle is Yβ2, f is the focal length of the first focusing lens group, Xβ is the scanning angle of the scanning structure, Xβ1 and Xβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure, Yβ is the scanning angle of the scanning structure, and Yβ1 and Yβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure.

[0006] Wherein, the spectral confocal measurement sensor meets the following conditions: d = |dn-d1| = |1 / ((A+B / (λn) 2 +C / (λn) 4 -1)×K) - 1 / ((A+B / (λ1) 2 +C / (λ1) 4 -1)×K)|; Wherein, d is the measurement range of the measurement beam along the Z axis, dn is the measurement size of the sub-beam along the Z axis when it hits the farthest surface to be measured of the object to be measured, d1 is the measurement size of the sub-beam along the Z axis when it hits the closest surface to be measured of the object to be measured, λn is the wavelength of the sub-beam hitting the farthest surface to be measured of the object to be measured, λ1 is the wavelength of the sub-beam hitting the closest surface to be measured of the object to be measured, A, B, and C are all fitting coefficients, and K is the constant value obtained by designing the first focusing lens group.

[0007] Wherein, the spectral confocal measurement sensor meets the following conditions: 1.3≤A≤2; -1≤B≤1; -1≤C≤1; -1≤K≤1.

[0008] Wherein, the spectral confocal measurement sensor meets the following conditions: λ = a × P + b, and 0≤a≤1, -100≤b≤100; Wherein, λ is the wavelength of the sub-beam, P is the pixel value of the sub-beam incident on the corresponding pixel position of the image sensor, and a and b are fitting coefficients.

[0009] Wherein, the spectral confocal measurement sensor further includes: a second focusing lens group, disposed between the beam splitter element and the diffraction grating, the second focusing lens group being used to receive and focus the feedback light beam from the beam splitter element; The third focusing lens group is disposed between the diffraction grating and the image sensor. The third focusing lens group is used to receive and focus the multiple sub-beams from the diffraction grating, and also allows the focused sub-beams to be directed to the image sensor.

[0010] Wherein, the spectral confocal measurement sensor further includes: The filter is disposed between the second focusing lens group and the diffraction grating, and has a slit; wherein the feedback light beam focused by the second focusing lens group converges at the slit.

[0011] Wherein, the spectral confocal measurement sensor further includes: a first collimating lens group, disposed between the light source and the beam splitter, for receiving the measuring beam from the light source and converting it into parallel light, and further directing the parallel measuring beam to the beam splitter; The second collimating lens group is disposed between the filter and the diffraction grating. The second collimating lens group is used to receive the feedback light beam from the slit and convert it into parallel light, and also to allow the parallel feedback light beam to be directed to the diffraction grating.

[0012] A second aspect of the present application provides a measurement method, the measurement method comprising: Providing a spectral confocal measurement sensor as provided in the first aspect of the present application; controlling the light source to output a measuring light beam; controlling the light splitting element to receive and transmit the measuring light beam from the light source; controlling the scanning structure to receive the measuring light beam from the light splitting element, and controlling the scanning structure to rotate; controlling the first focusing lens group to receive and focus the measuring beam from the scanning structure, and further directing the focused measuring beam toward the object to be measured; further, the measuring beam is reflected by the object to be measured to form a feedback beam, the first focusing lens group being configured to receive the feedback beam from the object to be measured and convert it into parallel light, and further directing the parallel feedback beam toward the scanning structure, which reflects the feedback beam toward the spectroscopic element; controlling the diffraction grating to receive the feedback light beam reflected from the beam splitter element, and further to decompose the feedback light beam into a plurality of sub-beams with different wavelengths; controlling the image sensor to receive the plurality of sub-beams, wherein the plurality of sub-beams are respectively emitted to different pixel positions of the image sensor; The data processor is controlled to correspond the wavelength information of the plurality of sub-beams according to the pixel information of the image sensor, and calculate the position information of the object to be measured, thereby obtaining the surface information of the object to be measured.

[0013] The spectral confocal measurement sensor and measurement method provided in the present application, by setting a scanning structure, can control the rotation of the scanning structure to change the position of the measuring beam, thereby realizing rapid scanning on the surface to be measured of the object to be measured, thereby expanding the traditional single-point or single-line measurement to surface measurement, so as to obtain height information of each point on the surface to be measured and topography information of the surface to be measured; moreover, the spectral confocal measurement sensor provided in the present application can adapt to different measurement needs, and can scan surfaces with regular shapes or surfaces with complex shapes, ensuring that the measuring beam can cover all areas to be measured as much as possible, avoiding measurement blind spots, thereby improving the measurement efficiency of the spectral confocal measurement sensor, improving the accuracy of the spectral confocal measurement sensor, and realizing high-precision and high-efficiency surface measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0015] Figure 1 This is a schematic structural diagram of a spectral confocal measurement sensor provided in one embodiment of the present application.

[0016] Figure 2 A three-dimensional structural diagram of a spectral confocal measurement sensor provided in one embodiment of the present application.

[0017] Figure 3 A schematic diagram of the rotation of the scanning structure provided in one embodiment of the present application.

[0018] Figure 4 Schematic diagram of the optical path of a spectral confocal measurement sensor provided in one embodiment of the present application.

[0019] Figure 5 Schematic diagram of the measurement range L of the measurement beam along the X-axis and the Y-axis in one embodiment of the present application.

[0020] Figure 6 This is a schematic diagram of light of different wavelengths converging to a surface to be measured at different distances in one embodiment of the present application.

[0021] Figure 7 Schematic diagram of a measurement range d of a measurement beam along the Z axis in one embodiment of the present application.

[0022] Explanation of reference numerals: spectral confocal measurement sensor 1, light source 10, spectrometer 20, scanning structure 30, first focusing lens group 41, second focusing lens group 42, third focusing lens group 43, diffraction grating 50, image sensor 60, filter 70, first collimating lens group 81, second collimating lens group 82, surface to be measured 90, nearest surface to be measured 91, farthest surface to be measured 92. DETAILED DESCRIPTION

[0023] The following are preferred implementations of the present application. It should be noted that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

[0024] Before introducing the technical solutions of the present application, the technical problems in the related technologies are introduced in detail.

[0025] First, traditional spectral confocal sensors have a limited measurement range: they can typically only perform single-point or single-line measurements, limiting their measurement range and making it difficult to quickly acquire surface topography information over large areas. In scenarios requiring large-area measurements, such as industrial inspection and cultural relic scanning, single-point or single-line measurements are extremely inefficient and cannot meet practical needs. For example, in surface quality inspection of automotive parts, using traditional spectral confocal sensors to measure the entire part surface piece by piece is extremely time-consuming, severely impacting production efficiency.

[0026] Secondly, traditional spectral confocal sensors suffer from low measurement efficiency: For tasks requiring large-area measurements, traditional measurement methods require multiple movements of the sensor or the object being measured. This is not only cumbersome and prone to introducing errors from the displacement platform itself, but also takes a long time to measure, and the subsequent data splicing algorithm is complex and lacks robustness. This has become a key factor restricting production progress in scenarios requiring high measurement efficiency, such as online production testing and rapid quality assessment.

[0027] Furthermore, traditional spectral confocal sensors have limitations when measuring complex surfaces: They struggle to fully cover and measure surfaces with complex shapes and structures, and are prone to blind spots. For example, when measuring complex curved parts like aircraft engine blades, traditional measurement methods may be unable to obtain accurate data on key areas of the blade, impacting product quality assessment and subsequent processing.

[0028] In view of this, in order to solve the above problems, please refer to Figure 1-Figure 7 This embodiment provides a spectral confocal measurement sensor 1, which includes a light source 10, a spectroscopic element 20, a scanning structure 30, a first focusing lens assembly 41, a diffraction grating 50, an image sensor 60, and a data processor. The light source 10 is configured to output a measurement beam; the spectroscopic element 20 is configured to receive and transmit the measurement beam from the light source 10; and the scanning structure 30 is configured to receive the measurement beam from the spectroscopic element 20. The scanning structure 30 is rotatable to change the position of the measurement beam.

[0029] The first focusing lens group 41 is used to receive and focus the measuring beam from the scanning structure 30, and also direct the focused measuring beam to the object under test. Moreover, the measuring beam is reflected by the object under test to form a feedback beam. The first focusing lens group 41 is used to receive the feedback beam from the object under test and convert it into parallel light. The feedback beam in the form of parallel light is also directed to the scanning structure 30. The scanning structure 30 reflects the feedback beam to the spectrometer 20.

[0030] The diffraction grating 50 is used to receive the feedback beam reflected from the spectrometer 20 and to decompose the feedback beam into multiple sub-beams with different wavelengths. The image sensor 60 is used to receive the multiple sub-beams, which are respectively emitted to different pixel positions of the image sensor 60.

[0031] The data processor is electrically connected to the image sensor 60 , and is used to correspond the wavelength information of the multiple sub-beams according to the pixel information of the image sensor 60 , calculate the position information of the object to be measured, and further obtain the surface information of the object to be measured.

[0032] The spectral confocal measurement sensor 1 is a high-precision measurement tool that combines confocal technology and spectral analysis, offering advantages such as non-contact, high precision, and high resolution. The spectral confocal measurement sensor 1 provided in this embodiment can be applied to fields such as automotive manufacturing, semiconductors, electronic equipment, and medical devices, without limitation in this embodiment.

[0033] Light source 10 is capable of emitting a measuring beam. Optionally, light source 10 comprises at least one of a point light source, a line light source, and a surface light source. Furthermore, light source 10 may be a high-brightness LED (Light Emitting Diode), a supercontinuum laser, or a xenon lamp. The measuring beam emitted by light source 10 has a continuous spectrum.

[0034] The spectroscopic element 20 can receive and transmit the measurement beam, and can also reflect the feedback beam. Optionally, the spectroscopic element 20 is disposed between the light source 10 and the scanning structure 30. Optionally, the spectroscopic element 20 is a semi-transparent, semi-reflective flat glass or a semi-transparent, semi-reflective spectroscopic prism. Preferably, the spectroscopic element 20 is a spectroscopic prism, which can adjust the optical path difference to achieve high-precision measurement of physical quantities such as micro-displacements. Further preferably, the spectroscopic prism has a 50:50 splitting ratio.

[0035] The scanning structure 30 receives the measurement beam from the spectrometer 20 and reflects it toward the first focusing lens group 41. Optionally, the scanning structure 30 is positioned between the spectrometer 20 and the first focusing lens group 41. Rotating the scanning structure 30 changes its scanning angle, thereby altering the position at which the measurement beam strikes the object under test, enabling surface measurement. Optionally, the scanning structure 30 may be comprised of components such as a microelectromechanical system (MEMS), a galvanometer, or a rotating mirror. Optionally, the scanning structure 30 is capable of rotating horizontally and / or vertically.

[0036] For example, the scanning mechanism 30 is driven by a high-precision motor, which can quickly and accurately control the angle of the reflector. By controlling the swing of the reflector, the measurement beam can be quickly scanned across the surface 90 of the object to be measured, thereby expanding single-point or single-line measurement to surface measurement.

[0037] For another example, the scanning structure 30 is a galvanometer, which can swing rapidly in the horizontal and vertical directions, so that the measuring beam can scan the surface 90 of the object to be measured according to a preset pattern (such as a rectangle, spiral, etc.).

[0038] Optionally, the scanning structure 30 features multiple scanning modes to accommodate varying measurement requirements. For regularly shaped surfaces, a rectangular scanning mode can be employed to quickly cover the entire measurement area. For complex surfaces, an adaptive scanning mode can be employed to adjust the scanning path based on pre-acquired surface profile information, ensuring that the measurement beam covers the entire measurement area as closely as possible. Furthermore, different scanning speeds and resolutions can be set to improve measurement efficiency while maintaining measurement accuracy.

[0039] The first focusing lens group 41 is capable of receiving and focusing the measurement beam from the scanning structure 30, and directing the focused measurement beam toward the object to be measured, ensuring that the size and position of the light spot meet measurement requirements. The first focusing lens group 41 is also capable of receiving a feedback beam from the object to be measured and converting it into parallel light, and directing the parallel feedback beam toward the scanning structure 30. Optionally, the first focusing lens group 41 is positioned between the scanning structure 30 and the object to be measured. Specifically, the first focusing lens group 41 is composed of a plurality of first lenses, which may be convex lenses, concave lenses, or aspherical lenses, among others. The type and arrangement of the first lenses can be configured based on product requirements.

[0040] Optionally, the first focusing lens group 41 is a dispersion-Fθ lens. The first focusing lens group 41 not only has a strong dispersion capability, but also has a distortion characteristic with the same magnitude as the scanning distortion but opposite sign. This characteristic can effectively offset the distortion introduced by the scanning structure 30, thereby ensuring the accuracy of the measurement.

[0041] Due to the difference in focusing characteristics of light of different wavelengths, the distance between the convergence point and the first focusing lens group 41 is different. Moreover, as the scanning angle changes, the position of the light on the test surface 90 of the object to be tested also varies. Figure 6 As shown, λ1 corresponds to the nearest surface to be measured 91, and λn corresponds to the farthest surface to be measured 92, thereby establishing a corresponding relationship between distance and wavelength.

[0042] The diffraction grating 50 receives the feedback beam reflected from the beam splitter 20 and decomposes it into multiple sub-beams of varying wavelengths. Optionally, the diffraction grating 50 is positioned between the first focusing lens assembly 41 and the image sensor 60. According to the principle of diffraction, sub-beams of different wavelengths experience different diffraction angles. Due to these different diffraction angles, sub-beams of different wavelengths strike different pixels on the image sensor 60, thereby establishing a correspondence between wavelength and pixel value.

[0043] Image sensor 60 is capable of receiving multiple sub-beams. Optionally, image sensor 60 is a CMOS image sensor or a CCD image sensor. Specifically, image sensor 60 is capable of converting optical signals into electrical signals. Image sensor 60 has different pixel locations, for example, each pixel location comprises a different photosensitive element. When a sub-beam strikes a pixel location, image sensor 60 generates an electrical signal, which is then transmitted to a data processor.

[0044] The data processor is capable of receiving and processing pixel information from the image sensor 60. The surface information of the object to be measured includes the height information and topography information of each point on the surface to be measured 90 of the object to be measured. The data processor obtains the electrical signal of the image sensor 60, thereby obtaining the light signal reflected by the measuring light beam. Specifically, by calibrating the distance-wavelength and wavelength-pixel value, the information of the current measuring position can be obtained based on the pixel value triggered on the image sensor 60, and ultimately accurate measurement can be achieved. For example, during the scanning process of the scanning structure 30, the data processor synchronously collects the light signal reflected by the measuring light beam, analyzes the collected light signal through spectral confocal technology, and obtains the height information of each point on the surface to be measured 90 of the object to be measured and the topography information of the surface to be measured 90.

[0045] Optionally, a high-speed data processing system can be used to process and store the collected data in real time for subsequent analysis and application. For example, hardware devices such as field programmable gate arrays (FPGAs) or digital signal processors (DSPs) can be used for data processing to enable rapid processing and storage of large amounts of measurement data.

[0046] In one embodiment, a point light source combined with X- and Y-axis dual-axis scanning can be used for data acquisition, suited for a linear array CCD / CMOS sensor. Alternatively, in another embodiment, a linear light source combined with single-axis scanning can be more appropriately adapted for an area array CCD / CMOS sensor. Furthermore, the scanning area can be flexibly adjusted to meet specific measurement requirements. For example, the scanning frequency can be increased for key scanning areas to obtain more detailed measurement data.

[0047] In summary, the spectral confocal measurement sensor 1 provided in this embodiment, by setting a scanning structure 30, can control the rotation of the scanning structure 30 to change the position of the measuring light beam, thereby realizing rapid scanning on the surface to be measured 90 of the object to be measured, thereby expanding the traditional single-point or single-line measurement to surface measurement, so as to obtain height information of each point on the surface to be measured 90 and morphology information of the surface to be measured 90; and the spectral confocal measurement sensor 1 provided in this application can adapt to different measurement needs, and can scan surfaces with regular shapes or surfaces with complex shapes, ensuring that the measuring light beam can cover all areas to be measured as much as possible, avoiding measurement blind spots, thereby improving the measurement efficiency of the spectral confocal measurement sensor 1, improving the accuracy of the spectral confocal measurement sensor 1, and realizing high-precision and high-efficiency surface measurement.

[0048] Please refer to Figure 1-Figure 5 In one embodiment, the spectral confocal measurement sensor 1 satisfies the following conditions: Lx = |Lx2-Lx1| =f × |tan(Xβ1)-tan(Xβ0)| + f × |tan(Xβ2)-tan(Xβ0)|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measuring beam along the X-axis, Lx1 is the measured dimension of the scanning structure 30 along the X-axis when the scanning angle is Xβ1, Lx2 is the measured dimension of the scanning structure 30 along the X-axis when the scanning angle is Xβ2, f is the focal length of the first focusing lens group 41, Xβ is the scanning angle of the scanning structure 30, and Xβ0 represents the scanning angle of the scanning structure 30 at the initial position, and Xβ1 and Xβ2 represent scanning angles of the same size but opposite directions in the scanning structure 30.

[0049] The spectral confocal measurement sensor 1 also meets the following conditions: Ly = |Ly2-Ly1| = f × |tan(Yβ1)-tan(Yβ0)| + f × |tan(Yβ2)-tan(Yβ0)|, and 5≤f≤1000; Wherein, Ly is the measurement range of the measuring beam along the Y-axis, Ly1 is the measured dimension along the Y-axis when the scanning angle of the scanning structure 30 is Yβ1, Ly2 is the measured dimension along the Y-axis when the scanning angle of the scanning structure 30 is Yβ2, f is the focal length of the first focusing lens group 41, Yβ is the scanning angle of the scanning structure 30, and Yβ0 represents the scanning angle of the scanning structure 30 at the initial position, and Yβ1 and Yβ2 represent scanning angles of the same size but opposite directions in the scanning structure 30.

[0050] One of Lx and Ly can be understood as the length range of the test surface 90 of the object to be tested that can be measured, and the other of Lx and Ly can be understood as the width range of the test surface 90 of the object to be tested that can be measured. Figure 4 and Figure 5 The L in can represent both Lx and Ly. Figure 4 As shown in L1, Lx2 and Ly2 are as follows Figure 4 L0 is the measurement size along the X axis when the scanning angle of the scanning structure 30 is Xβ0, or the measurement size along the Y axis when the scanning angle of the scanning structure 30 is Yβ0.

[0051] The focal length f of the first focusing lens assembly 41 can be, for example, 5, 25, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000. Preferably, the focal length of the first focusing lens assembly 41 is 5 ≤ ​​f ≤ 800. More preferably, the focal length of the first focusing lens assembly 41 is 5 ≤ ​​f ≤ 500. Even more preferably, the focal length of the first focusing lens assembly 41 is 5 ≤ ​​f ≤ 300.

[0052] When scanning distortion compensation is not considered for the first focusing lens group 41, Lx satisfies f × |tan(Xβ1)-tan(Xβ0)| + f × |tan(Xβ2)-tan(Xβ0)|, and Ly satisfies f × |tan(Yβ1)-tan(Yβ0)| + f × |tan(Yβ2)-tan(Yβ0)|. This design has the advantages of low design difficulty for the first focusing lens group 41, low R&D costs, and low manufacturing costs, and can meet the requirements of most applications for spectral confocal measurement sensors with single-surface measurements. However, the measurement range L corresponding to different scanning angles is nonlinear.

[0053] In another embodiment, the spectral confocal measurement sensor 1 satisfies the following conditions: Lx = |Lx2-Lx1| = f × |Xβ1-Xβ2|, Ly = |Ly2-Ly1| = f × |Yβ1-Yβ2|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measurement beam along the X-axis, Lx1 is the measurement dimension of the scanning structure 30 along the X-axis when the scanning angle is Xβ1, Lx2 is the measurement dimension of the scanning structure 30 along the X-axis when the scanning angle is Xβ2, Ly is the measurement range of the measurement beam along the Y-axis, Ly1 is the measurement dimension of the scanning structure 30 along the Y-axis when the scanning angle is Yβ1, Ly2 is the measurement dimension of the scanning structure 30 along the Y-axis when the scanning angle is Yβ2, f is the focal length of the first focusing lens group 41, Xβ is the scanning angle of the scanning structure 30, and Xβ1 and Xβ2 represent scanning angles of the same size but opposite directions in the scanning structure 30, Yβ is the scanning angle of the scanning structure 30, and Yβ1 and Yβ2 represent scanning angles of the same size but opposite directions in the scanning structure 30.

[0054] When the first focusing lens group 41 takes scanning distortion compensation into account, Lx satisfies f × |Xβ1-Xβ2| and Ly satisfies f × |Yβ1-Yβ2|. This design has the advantage of a linear measurement range L corresponding to different scanning angles, low data processing difficulty, and high measurement accuracy. This design can meet the requirements of spectral confocal measurement sensors for one surface in applications requiring higher measurement accuracy. However, the design of the first focusing lens group 41 is difficult and the R&D cost is high.

[0055] Please refer to Figure 1-Figure 2 、 Figure 6-Figure 7 In one embodiment, the spectral confocal measurement sensor 1 satisfies the following conditions: d = |dn-d1| = |1 / ((A+B / (λn) 2 +C / (λn) 4 -1)×K) - 1 / ((A+B / (λ1) 2 +C / (λ1) 4 -1)×K)|; Wherein, d is the measurement range of the measuring beam along the Z axis, dn is the measurement size of the sub-beam along the Z axis when it hits the farthest surface to be measured 92 of the object to be measured, d1 is the measurement size of the sub-beam along the Z axis when it hits the closest surface to be measured 91 of the object to be measured, λn is the wavelength of the sub-beam hitting the farthest surface to be measured 92 of the object to be measured, λ1 is the wavelength of the sub-beam hitting the closest surface to be measured 91 of the object to be measured, A, B, and C are all fitting coefficients, and K is the constant value obtained by designing the first focusing lens group 41.

[0056] d can be understood as the height range of the measured surface 90 of the object to be measured, dn, d1 as Figure 7As shown, λ represents the different wavelengths of the multiple sub-beams. Due to the differences in focusing characteristics of light of different wavelengths, the distances between their convergence points and the first focusing lens group 41 are different, so the sub-beams of different wavelengths are positioned at different heights on the test surface 90 of the object to be measured.

[0057] The specific value of K depends on the focal length f of the first focusing lens assembly 41 and its equivalent refractive index for light of different wavelengths during lens assembly design. It is generally calculated as 1 / f multiplied by a coefficient that varies with wavelength. Once the first focusing lens assembly 41 is designed, the K value can be calculated and used as a fixed constant.

[0058] In one embodiment, the spectral confocal measurement sensor 1 satisfies the following conditions: 1.3≤A≤2; -1≤B≤1; -1≤C≤1; -1≤K≤1.

[0059] The fitting coefficient A can be specifically exemplified as 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2. Preferably, the fitting coefficient A is: 1.5≤A≤1.8.

[0060] The fitting coefficient B can be specifically exemplified as -1, -0.8, -0.6, -0.4, -0.2, 0, 0.2, 0.4, 0.6, 0.8, or 1. Preferably, the fitting coefficient B is: -0.5≤B≤0.5.

[0061] The fitting coefficient C can be specifically exemplified by -1, -0.8, -0.6, -0.4, -0.2, 0, 0.2, 0.4, 0.6, 0.8, or 1. Preferably, the fitting coefficient C is: -0.5≤C≤0.5.

[0062] Specific examples of the constant value K include -1, -0.8, -0.6, -0.4, -0.2, 0, 0.2, 0.4, 0.6, 0.8, 1, etc. Preferably, the constant value K is: -0.5≤K≤0.5.

[0063] The fitting coefficients A, B, and C can be obtained through design or actual measurement, and K is a constant value obtained by designing the first focusing lens group 41. By limiting the fitting coefficients A, B, and C and the constant value K in the above relationship, this embodiment can effectively improve the measurement accuracy of the spectral confocal measurement sensor 1, reduce systematic errors, and ensure measurement stability and reliability.

[0064] Different positions on the test surface 90 have the same or different heights. Optionally, the height of the farthest test surface 92 of the object to be tested is 0. The corresponding relationship between the height h on the test surface 90 of the object to be tested and the wavelength λ satisfies the following equation: h = dn - dt = 1 / ((A + B / (λn) 2+C / (λn) 4 -1)×K) - 1 / ((A+B / (λt) 2 +C / (λt) 4 -1)×K), dn>dt; Wherein, dn is the measured dimension along the Z axis when the sub-beam is incident on the farthest surface to be measured 92 of the object to be measured, dt is the measured dimension along the Z axis when the sub-beam is incident on the surface to be measured 90 of the object to be measured, λn is the wavelength of the sub-beam incident on the farthest surface to be measured 92 of the object to be measured, λt is the wavelength of the sub-beam incident on the surface to be measured 90 of the object to be measured, A, B, and C are all fitting coefficients, and K is a constant value obtained by designing the first focusing lens group 41.

[0065] In one embodiment, the spectral confocal measurement sensor 1 satisfies the following conditions: λ = a × P + b, and 0≤a≤1, -100≤b≤100; Wherein, λ is the wavelength of the sub-beam, P is the pixel value of the sub-beam incident on the corresponding pixel position of the image sensor 60, and a and b are fitting coefficients.

[0066] The diffraction angles of sub-beams of different wavelengths are different. Due to the different diffraction angles, the sub-beams of different wavelengths strike different pixel positions of the image sensor 60, thereby forming a corresponding relationship between wavelength and pixel value.

[0067] The fitting coefficient a can be specifically exemplified as 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1. Preferably, the fitting coefficient a is: 0.2≤a≤0.8.

[0068] The fitting coefficient b can be specifically exemplified as -100, -80, -60, -40, -20, 0, 20, 40, 60, 80, 100, etc. Preferably, the fitting coefficient b is: -50≤b≤50.

[0069] The fitting coefficients a and b can be obtained through design or actual measurement. In this embodiment, the relationship between the wavelength λ and the pixel P satisfies a linear relationship. By limiting the fitting coefficients a and b in the above relationship, it is beneficial to adapt to different measurement objects, facilitate the debugging and calibration of the equipment, reduce system errors, and ensure the stability and reliability of the measurement.

[0070] Please refer to Figure 1-Figure 2In one embodiment, the spectral confocal measurement sensor 1 further includes a second focusing lens group 42 and a third focusing lens group 43. The second focusing lens group 42 is disposed between the beam splitter 20 and the diffraction grating 50 and is configured to receive and focus the feedback beam from the beam splitter 20. The third focusing lens group 43 is disposed between the diffraction grating 50 and the image sensor 60 and is configured to receive and focus multiple sub-beams from the diffraction grating 50 and direct the focused sub-beams toward the image sensor 60.

[0071] The second focusing lens assembly 42 receives and focuses the feedback beam from the beam splitter 20 and directs the focused feedback beam toward the slit of the filter 70. Specifically, the second focusing lens assembly 42 is composed of a plurality of second lenses, which can be convex, concave, or aspherical lenses. The type and arrangement of the second lenses can be customized based on product requirements.

[0072] In this embodiment, the second focusing lens group 42 is provided to collect and converge more feedback light beams to be emitted to the filter 70 , so as to improve the measurement accuracy of the spectral confocal measurement sensor 1 .

[0073] The third focusing lens assembly 43 receives and focuses the multiple sub-beams from the diffraction grating 50 and directs these focused sub-beams toward the image sensor 60. Specifically, the third focusing lens assembly 43 is composed of multiple third lenses, which can be convex, concave, or aspherical. The type and arrangement of the third lenses can be customized based on product requirements. After being focused by the third focusing lens assembly 43, sub-beams of different wavelengths converge onto different pixel locations on the image sensor 60 due to varying diffraction angles, thereby establishing a correspondence between wavelength and pixel value.

[0074] In this embodiment, a third focusing lens group 43 is provided to form a correspondence between wavelength and pixel value to obtain surface information of the object to be measured.

[0075] Please refer to Figure 1-Figure 2 In one embodiment, the spectral confocal measurement sensor 1 further includes a filter 70, which is disposed between the second focusing lens group 42 and the diffraction grating 50, and the filter 70 has a slit; wherein the feedback light beam focused by the second focusing lens group 42 converges at the slit.

[0076] The filter 70 can filter stray light, thereby forming a confocal system and significantly improving the signal-to-noise ratio of the measurement. Optionally, the slit can be in the form of a pinhole or a rectangle, and this embodiment does not limit the form of the slit. The feedback beam from the second focusing lens assembly 42 converges at the slit. After passing through the slit, the feedback beam begins to diffuse and is directed to the second collimating lens assembly 82.

[0077] In this embodiment, the optical filter 70 is provided to filter stray light, thereby improving the signal-to-noise ratio of the measurement, thereby improving the measurement accuracy of the spectral confocal measurement sensor 1 .

[0078] Please refer to Figure 1-Figure 2 In one embodiment, the spectral confocal measurement sensor 1 further includes a first collimator lens group 81 and a second collimator lens group 82. The first collimator lens group 81 is disposed between the light source 10 and the spectrometer 20. The first collimator lens group 81 is used to receive the measurement beam from the light source 10 and convert it into parallel light, and further direct the measurement beam in the form of parallel light to the spectrometer 20. The second collimator lens group 82 is disposed between the filter 70 and the diffraction grating 50. The second collimator lens group 82 is used to receive the feedback beam from the slit and convert it into parallel light, and further direct the feedback beam in the form of parallel light to the diffraction grating 50.

[0079] The first collimating lens group 81 is capable of receiving the measuring beam from the light source 10 and converting the measuring beam into parallel light, and further directing the parallel measuring beam to the beam splitter 20. Specifically, the first collimating lens group 81 is composed of a plurality of first collimating sub-mirrors, which can be convex lenses, concave lenses, etc.

[0080] In this embodiment, a first collimating lens group 81 is provided to make the measuring light beam entering the spectroscopic element 20 parallel light, so as to improve the spectroscopic performance of the spectroscopic element 20 .

[0081] The second collimating lens group 82 can receive the feedback light beam from the slit and convert the feedback light beam into parallel light, and also direct the parallel feedback light beam to the diffraction grating 50. Specifically, the second collimating lens group 82 is composed of a plurality of second collimating sub-mirrors, which can be convex lenses, concave lenses, etc.

[0082] In this embodiment, a second collimating lens group 82 is provided to make the feedback light beam entering the diffraction grating 50 parallel light, so as to improve the light splitting performance of the diffraction grating 50 .

[0083] The present application also provides a measurement method, which includes: A spectral confocal measurement sensor as provided above in the present application is provided.

[0084] The light source is controlled to output a measuring beam.

[0085] The light splitting element is controlled to receive and transmit the measuring light beam from the light source.

[0086] The scanning structure is controlled to receive the measuring light beam from the light splitting element, and the scanning structure is controlled to rotate.

[0087] The first focusing lens group is controlled to receive and focus the measuring light beam from the scanning structure, and further direct the focused measuring light beam toward the object to be measured; further, the measuring light beam is reflected by the object to be measured to form a feedback light beam, the first focusing lens group is used to receive the feedback light beam from the object to be measured and convert it into parallel light, and further direct the feedback light beam in the form of parallel light toward the scanning structure, and the scanning structure reflects the feedback light beam toward the spectroscopic element.

[0088] The diffraction grating is controlled to receive the feedback light beam reflected from the beam splitter element, and is also used to decompose the feedback light beam into a plurality of sub-beams with different wavelengths.

[0089] The image sensor is controlled to receive the multiple sub-beams, and the multiple sub-beams are respectively emitted to different pixel positions of the image sensor.

[0090] The data processor is controlled to correspond the wavelength information of the plurality of sub-beams according to the pixel information of the image sensor, and calculate the position information of the object to be measured, thereby obtaining the surface information of the object to be measured.

[0091] Specifically, the measurement beam emitted from the light source first passes through the first collimating lens group. This collimation process collimates the measurement beam into parallel light, which then passes through the beam splitter. Next, the measurement beam reaches the scanning structure, is reflected by the scanning structure, and then passes through the first focusing lens group, converging onto the surface of the object under test.

[0092] Due to differences in focusing properties between different wavelengths of light, the distance between their convergence point and the first focusing lens group varies. Furthermore, as the scanning angle changes, the position of the measurement beam on the surface under test also varies, thus establishing a corresponding relationship between distance and wavelength.

[0093] When the measuring beam strikes the surface to be measured and reflects, it forms a feedback beam. Based on the principle of reversible optical paths, the feedback beam is collimated into parallel light by the first focusing lens group. It then passes through the scanning structure and reflects back to the beam splitter. After reflection from the beam splitter, the feedback beam enters the second focusing lens group and converges at the slit in the filter. After passing through the slit, the converged light begins to diffuse before being collimated into parallel light by the second collimating lens group. This parallel light is then split by a diffraction grating. According to the principle of diffraction, different wavelengths of light have different diffraction angles. After being focused by the third focusing lens group, the different diffraction angles cause different wavelengths of light to converge at different pixel locations on the image sensor, establishing a corresponding relationship between wavelength and pixel value. By calibrating the distance-wavelength and wavelength-pixel values, the height information and topography of each point on the surface to be measured can be obtained based on the triggered pixel values ​​on the image sensor, enabling high-precision and efficient surface measurement.

[0094] In summary, this embodiment adopts the spectral confocal measurement sensor provided above in this application, and by setting a scanning structure, it is possible to control the rotation of the scanning structure to change the position of the measuring beam, thereby realizing rapid scanning on the surface to be measured of the object to be measured, thereby expanding the traditional single-point or single-line measurement to surface measurement, so as to obtain height information and morphology information of each point on the surface to be measured; and the spectral confocal measurement sensor provided in this application can adapt to different measurement needs, and can scan surfaces with regular shapes or surfaces with complex shapes, ensuring that the measuring beam can cover all areas to be measured as much as possible, avoiding measurement blind spots, thereby improving the measurement efficiency of the spectral confocal measurement sensor, improving the accuracy of the spectral confocal measurement sensor, and realizing high-precision and high-efficiency surface measurement.

[0095] Unless otherwise specified or incompatible therewith, terms and phrases used in this application shall have the following meanings: In this application, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of the features.

[0096] In this application, "one or several" refers to any one, any two, or any two or more of the listed items. Among them, "several" refers to any two or any two or more.

[0097] In the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0098] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connections, removable connections, or integration. They may refer to mechanical connections or electrical connections. They may refer to direct connections or indirect connections through an intermediary. They may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0099] Mentioning "embodiments" and "implementation methods" in this application means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrases in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments. In addition, it should be understood that the features, structures or characteristics described in the various embodiments of the present application can be arbitrarily combined to form another embodiment that does not deviate from the spirit and scope of the technical solution of the present application, unless there is a contradiction between them.

[0100] The above is part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A spectral confocal measurement sensor, characterized in that: The spectral confocal measurement sensor comprises: a light source, for outputting a measuring light beam; a beam splitter element for receiving and transmitting the measuring beam from the light source; a scanning structure for receiving the measuring beam from the beam splitter, wherein the scanning structure is rotatable to change the position of the measuring beam; a first focusing lens assembly, configured to receive and converge the measuring beam from the scanning structure, and direct the converged measuring beam toward the object to be measured; wherein the measuring beam is reflected by the object to be measured to form a feedback beam, the first focusing lens assembly is configured to receive the feedback beam from the object to be measured and convert it into parallel light, and direct the parallel feedback beam toward the scanning structure, which reflects the feedback beam toward the spectroscopic element; a diffraction grating, configured to receive the feedback beam reflected from the beam splitter, and further configured to decompose the feedback beam into a plurality of sub-beams with different wavelengths; an image sensor, configured to receive the plurality of sub-beams, wherein the plurality of sub-beams are respectively directed to different pixel positions of the image sensor; A data processor is electrically connected to the image sensor, and is used to correspond the wavelength information of the multiple sub-beams according to the pixel information of the image sensor, and calculate the position information of the object to be measured, thereby obtaining the surface information of the object to be measured.

2. The spectral confocal measurement sensor according to claim 1, wherein: The spectral confocal measurement sensor meets the following conditions: Lx = |Lx2-Lx1| =f × |tan(Xβ1)-tan(Xβ0)| + f × |tan(Xβ2)-tan(Xβ0)|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measurement beam along the X-axis, Lx1 is the measurement size of the scanning structure along the X-axis when the scanning angle is Xβ1, Lx2 is the measurement size of the scanning structure along the X-axis when the scanning angle is Xβ2, f is the focal length of the first focusing lens group, Xβ is the scanning angle of the scanning structure, and Xβ0 represents the scanning angle of the scanning structure at the initial position, and Xβ1 and Xβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure; The spectral confocal measurement sensor also meets the following conditions: Ly = |Ly2-Ly1| = f × |tan(Yβ1)-tan(Yβ0)| + f × |tan(Yβ2)-tan(Yβ0)|, and 5≤f≤1000; Wherein, Ly is the measurement range of the measuring beam along the Y-axis, Ly1 is the measured dimension of the scanning structure along the Y-axis when the scanning angle is Yβ1, Ly2 is the measured dimension of the scanning structure along the Y-axis when the scanning angle is Yβ2, f is the focal length of the first focusing lens group, Yβ is the scanning angle of the scanning structure, and Yβ0 represents the scanning angle of the scanning structure at the initial position, and Yβ1 and Yβ2 represent scanning angles of the same size but opposite directions in the scanning structure.

3. The spectral confocal measurement sensor according to claim 1, wherein: The spectral confocal measurement sensor meets the following conditions: Lx = |Lx2-Lx1| = f × |Xβ1-Xβ2|, Ly = |Ly2-Ly1| = f × |Yβ1-Yβ2|, and 5≤f≤1000; Wherein, Lx is the measurement range of the measurement beam along the X-axis, Lx1 is the measurement dimension of the scanning structure along the X-axis when the scanning angle is Xβ1, Lx2 is the measurement dimension of the scanning structure along the X-axis when the scanning angle is Xβ2, Ly is the measurement range of the measurement beam along the Y-axis, Ly1 is the measurement dimension of the scanning structure along the Y-axis when the scanning angle is Yβ1, Ly2 is the measurement dimension of the scanning structure along the Y-axis when the scanning angle is Yβ2, f is the focal length of the first focusing lens group, Xβ is the scanning angle of the scanning structure, Xβ1 and Xβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure, Yβ is the scanning angle of the scanning structure, and Yβ1 and Yβ2 represent scanning angles of the same magnitude but opposite directions in the scanning structure.

4. The spectral confocal measurement sensor according to claim 1, wherein: The spectral confocal measurement sensor meets the following conditions: d = |dn-d1|=|1 / ((A+B / (λn) 2 +C / (λn) 4 -1)×K) - 1 / ((A+B / (λ1) 2 +C / (λ1) 4 -1)×K)|; Wherein, d is the measurement range of the measurement beam along the Z axis, dn is the measurement size of the sub-beam along the Z axis when it hits the farthest surface to be measured of the object to be measured, d1 is the measurement size of the sub-beam along the Z axis when it hits the closest surface to be measured of the object to be measured, λn is the wavelength of the sub-beam hitting the farthest surface to be measured of the object to be measured, λ1 is the wavelength of the sub-beam hitting the closest surface to be measured of the object to be measured, A, B, and C are all fitting coefficients, and K is the constant value obtained by designing the first focusing lens group.

5. The spectral confocal measurement sensor according to claim 4, characterized in that: The spectral confocal measurement sensor meets the following conditions: 1.3≤A≤2； -1≤B≤1； -1≤C≤1； -1≤K≤1。 6. The spectral confocal measurement sensor according to claim 1, wherein: The spectral confocal measurement sensor meets the following conditions: λ = a × P + b, and 0≤a≤1, -100≤b≤100; Wherein, λ is the wavelength of the sub-beam, P is the pixel value of the sub-beam incident on the corresponding pixel position of the image sensor, and a and b are fitting coefficients.

7. The spectral confocal measurement sensor according to claim 1, wherein: The spectral confocal measurement sensor further includes: a second focusing lens group, disposed between the beam splitter element and the diffraction grating, the second focusing lens group being used to receive and focus the feedback light beam from the beam splitter element; The third focusing lens group is disposed between the diffraction grating and the image sensor. The third focusing lens group is used to receive and focus the multiple sub-beams from the diffraction grating, and also allows the focused sub-beams to be directed to the image sensor.

8. The spectral confocal measurement sensor according to claim 7, characterized in that: The spectral confocal measurement sensor further includes: The filter is disposed between the second focusing lens group and the diffraction grating, and has a slit; wherein the feedback light beam focused by the second focusing lens group converges at the slit.

9. The spectral confocal measurement sensor according to claim 8, characterized in that: The spectral confocal measurement sensor further includes: a first collimating lens group, disposed between the light source and the beam splitter, for receiving the measuring beam from the light source and converting it into parallel light, and further directing the parallel measuring beam to the beam splitter; The second collimating lens group is disposed between the filter and the diffraction grating. The second collimating lens group is used to receive the feedback light beam from the slit and convert it into parallel light, and also to allow the parallel feedback light beam to be directed to the diffraction grating.

10. A measurement method, characterized in that: The measuring method comprises: Providing the spectral confocal measurement sensor according to claim 1; controlling the light source to output a measuring light beam; controlling the light splitting element to receive and transmit the measuring light beam from the light source; controlling the scanning structure to receive the measuring light beam from the light splitting element, and controlling the scanning structure to rotate; controlling the first focusing lens group to receive and focus the measuring beam from the scanning structure, and further directing the focused measuring beam toward the object to be measured; further, the measuring beam is reflected by the object to be measured to form a feedback beam, the first focusing lens group being configured to receive the feedback beam from the object to be measured and convert it into parallel light, and further directing the parallel feedback beam toward the scanning structure, which reflects the feedback beam toward the spectroscopic element; controlling the diffraction grating to receive the feedback light beam reflected from the beam splitter element, and further to decompose the feedback light beam into a plurality of sub-beams with different wavelengths; controlling the image sensor to receive the plurality of sub-beams, wherein the plurality of sub-beams are respectively emitted to different pixel positions of the image sensor; The data processor is controlled to correspond the wavelength information of the plurality of sub-beams according to the pixel information of the image sensor, and calculate the position information of the object to be measured, thereby obtaining the surface information of the object to be measured.

Images