Imaging method and structure light coding module for binary coding image

Abstract

The application relates to the technical field of structured light projection, in particular to an imaging method of a binary coded image and a structured light coding module, wherein the imaging method comprises the following steps: 1, a semiconductor refrigeration mode is adopted to control the temperature of an LCoS chip in the structured light coding module; 2, the structured light coding module is used to image on a measured object, a multi-line binary grating image is obtained, and the depth of field of the whole imaging surface is consistent; 3, a first-level coded image L is obtained according to the multi-line binary grating image; then a complementary Golay code coding strategy is adopted to construct Golay code images GC1 to GC5, and a second-level coded image K1 and a third-level coded image K2 are constructed according to the Golay code images GC1 to GC5; finally, the codes of the three levels of coded images L, the coded image K1 and the coded image K2 are added, and a final binary coded image is obtained. The application overcomes the low contrast problem of the LCoS chip and realizes robust structured light coding.

Description

Technical Field

[0001] This invention relates to the field of structured light projection technology, and in particular to an imaging method for a binary encoded image and a structured light encoding module. Background Technology

[0002] With the gradual localization of domestically produced Liquid Crystal on Silicon (LCoS) chips, the monopoly of Digital Micromirror Devices (DMD) chips in the market has been successfully broken, bringing new opportunities for the development of optical engine modules. However, LCoS chips have inherent defects during operation, such as low light utilization and low contrast. Furthermore, because the LCoS chips in projection optical engines are deployed at an angle, inconsistencies in depth of field and encoding ambiguity occur when measuring large objects. Additionally, with changes in ambient temperature, the components of the projection optical engine may shift due to thermal expansion and contraction. These problems severely restrict the performance improvement and display optimization of projection optical engines, limiting their widespread application in high-precision display fields. Summary of the Invention

[0003] This invention provides an imaging method for binarized coded images and a structured light coding module to solve the technical problems mentioned in the background art.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] This invention provides an imaging method for a binary coded image, comprising the following steps:

[0006] S1. Use semiconductor cooling to control the temperature of the LCoS chip in the structured light coding module so that the temperature of the LCoS chip is controlled within a set fluctuation range.

[0007] S2. The structured light coding module is used to image the object under test to obtain a multi-line binary grating image, and the depth of field of the structured light coding module is consistent on the imaging surface.

[0008] S3. Obtain the first-level coding map L based on the multi-line binarized raster image; then, use the complementary Gray code coding strategy to construct Gray code maps GC1 to GC5, and construct the second-level coding map K1 and the third-level coding map K2 based on Gray code maps GC1 to GC5. Finally, add the codes of the three-level coding maps L, K1, and K2 to obtain the final binarized coding map.

[0009] Furthermore, step S2 specifically includes the following steps:

[0010] S21. Turn on the light source; the light source emits a beam of light.

[0011] S22. The light beam emitted by the light source is focused by the condenser lens and then passes through the aspherical collimating lens to become parallel light.

[0012] S23. Parallel light passes through a compound eye lens and becomes multiple uniform parallel beams.

[0013] S24. The parallel light generated in S23 is transmitted, corrected, adjusted and distorted by a repeater mirror so that the beam transmitted by the repeater mirror matches the size of the LCoS chip.

[0014] S25. The beam transmitted from the relay mirror is transmitted to the polarization beam splitter. The polarization beam splitter reflects the beam with the set deflection angle onto the surface of the LCoS chip. The beams with other polarization angles are filtered by the polarization beam splitter. The LCoS chip performs pixel-level control on the polarization angle of the reflected beam to realize structured light encoding and reflection.

[0015] S26. The beam emitted after being encoded by the LCoS chip passes through a polarizing beam splitter and is projected onto the surface of the object being measured through a lens, resulting in a multi-line binarized grating pattern.

[0016] S27. By introducing the Sham projection principle to adjust the angle between the LCoS chip and the optical axis of the lens, the depth of field of the structured light coding module on the imaging surface is consistent, that is, the angle θ1 between the plane where the LCoS chip is located and the optical axis of the lens, and the angle θ2 between the optical axis of the lens and the normal direction of the imaging surface are equal.

[0017] Furthermore, step S3 specifically includes the following steps:

[0018] S31. Move the bright lines of the multi-line binarized raster image one pixel to the right multiple times according to the row to obtain a series of multi-line binarized raster images.

[0019] S32. Arrange a series of multi-line binarized raster images to obtain the first-level coded image L;

[0020] S33. Using a complementary Gray code encoding strategy, construct Gray code maps GC1 to GC5, a total of 5 Gray code maps; wherein, from Gray code map GC1 to Gray code map GC5, the codeword width of the next Gray code map is half the codeword width of the previous Gray code map;

[0021] S34. Encode Gray code maps GC1 to GC4 to obtain the second-level coding map K1. The specific calculation formula for coding map K1 is as follows:

[0022] K1 = GC1 + GC2 + GC3 + GC4;

[0023] Wherein, GC2 and GC3 represent Gray code map GC2 and Gray code map GC3, respectively;

[0024] S35. Encode Gray code maps GC2 to GC5 to obtain the third-level coding map K2; the specific formula for calculating coding map K2 is as follows:

[0025] K2 = GC2 + GC3 + GC4 + GC5;

[0026] S36. The codes of the three levels of coding maps L, K1, and K2 are added together to obtain the final binary coding map C. The specific formula for calculating the binary coding map C is as follows:

[0027] C = L + K1 + K2.

[0028] Furthermore, step S33 specifically includes the following steps:

[0029] S331. First, project to obtain Gray code maps GC1 to GC4, a total of 4 Gray code maps; starting from Gray code map GC1 and ending at Gray code map GC4, the codeword width of the next Gray code map is half the codeword width of the previous Gray code map;

[0030] S332. Then project a Gray code map GC5 with a codeword width that is half that of Gray code map GC4. Thus, a 5-bit Gray code map is obtained. The 5-bit Gray code map is used to construct 16 pixel periods, and each period has a unique corresponding Gray codeword.

[0031] In another aspect, the present invention provides a structured light coding module, which performs imaging using the above-described imaging method, including:

[0032] The housing has an internal space for receiving light, and light inlet and imaging holes are provided on both sides;

[0033] The light source is fixedly mounted on the outer wall of the housing close to the light inlet hole;

[0034] The parallel light imaging unit, installed within the housing's containment space, is used to convert light emitted from the light source into parallel light;

[0035] The relay mirror, installed within the housing's containment space, is used to optimize and transmit the light from the parallel light imaging unit.

[0036] A polarizing beam splitter is obliquely mounted in the housing's containment space to reflect beams with a set deflection angle and then filter beams with a deflection angle outside the set angle.

[0037] The LCoS chip is attached to the inner wall of the housing at a set Sham angle and is used to encode and reflect the beam reflected by the polarizing beam splitter.

[0038] The lens is fixedly mounted on the outer wall of the housing close to the imaging aperture. It is used to transmit the light beam reflected by the LCoS chip so that the light beam illuminates the surface of the object being measured.

[0039] Furthermore, the shell is made of Invar steel.

[0040] Furthermore, the light source is selected as an LED light source, and the LED (light-emitting diode) light source is used to provide blue light.

[0041] Furthermore, the structured light coding module also includes a heat sink, which is mounted on the light source through a thermally conductive material to achieve heat conduction and dissipation of the light source.

[0042] The light source is bonded to the outer wall of the housing with heat-insulating adhesive to prevent the heat generated by the light source from being conducted to the housing.

[0043] Furthermore, the parallel light imaging unit includes:

[0044] A condenser lens is installed within the housing's containment space and located between the light source and the relay lens to focus the light provided by the light source.

[0045] The collimating lens is installed within the housing's containment space and is located between the condenser lens and the relay lens. It is used to convert the light projected by the condenser lens into parallel light.

[0046] The compound eye lens is installed within the housing's containment space and positioned between the collimating lens and the relay lens. It is used to optimize the parallel light projected by the collimating lens to obtain uniform parallel light.

[0047] Furthermore, the parallel light imaging unit, relay mirror, and polarizing beam splitter are all made of quartz.

[0048] The beneficial effects of this invention are:

[0049] 1. This invention discloses an imaging method for a binary encoded image. The structured light encoding module is thermally analyzed using Ansys (a computer-aided engineering software). Based on the thermal analysis results and the optimized design of insulating adhesive, thermally conductive materials (preferably high thermal conductivity graphene materials), the temperature drift problem of the structured light encoding module is solved and the heat generation of the LCoS chip is controlled within an acceptable fluctuation range.

[0050] 2. This invention employs a complementary Gray code encoding strategy, constructing Gray code maps GC1 to GC5. Based on these maps, a second-level encoding map K1 and a third-level encoding map K2 are constructed. Finally, the codes of the three-level encoding maps L1, K1, and K2 are added together to obtain the final binarized encoding map. This invention relies on the LCoS chip to obtain the final binarized encoding map, overcoming the inherent low contrast problem of the LCoS chip. By optimizing the traditional encoding method, the spatial resolution is significantly improved, enhancing the clarity and detail of the projected image.

[0051] 3. This invention also discloses a structured light coding module, which has the advantages of high-efficiency optical transmission and high imaging accuracy. By effectively managing heat dissipation and temperature control of the structured light coding module, its stability and reliability under different operating conditions can be guaranteed. Attached Figure Description

[0052] Figure 1 This is a flowchart of the imaging method in this invention;

[0053] Figure 2 This is a schematic diagram of the imaging principle of the structured light coding module in this invention;

[0054] Figure 3 This is a structural diagram of the structured light coding module in this invention;

[0055] Figure 4 This is a schematic diagram of the thermal analysis results in an embodiment of the present invention;

[0056] Figure 5 This is a schematic diagram of a series of multi-line binarized raster patterns in an embodiment of the present invention;

[0057] Figure 6 The following is a schematic diagram of the Gray code diagrams in an embodiment of the present invention, wherein (a) is a schematic diagram of Gray code diagrams GC1 to GC4; and (b) is a schematic diagram of Gray code diagram GC5.

[0058] Figure 7 This is a schematic diagram of the final binarized encoding map in an embodiment of the present invention.

[0059] Explanation of reference numerals in the attached figures:

[0060] 1. Shell; 11. Retaining space;

[0061] 2. Light source;

[0062] 3. Parallel light imaging unit; 31. Condenser lens; 32. Collimating lens; 33. Compound eye lens;

[0063] 4. Repeater mirror;

[0064] 5. Polarizing beam splitter;

[0065] 6. LCoS chip;

[0066] 7. Lens. Detailed Implementation

[0067] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0068] It should be noted that when a component is referred to as "fixed" or "mounted" to another component, it can be directly or indirectly attached to that other component. When a component is referred to as "connected" to another component, it can be directly or indirectly connected to that other component.

[0069] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0070] It should also be noted that in the embodiments of this application, the same reference numerals are used to represent the same component or part. For the same part in the embodiments of this application, the reference numerals may only be used to mark one part or component as an example. It should be understood that the reference numerals are also applicable to other identical parts or components.

[0071] Reference Figure 1 This application provides an imaging method for a binary coded image, comprising the following steps:

[0072] S1. The temperature of the LCoS chip 6 in the structured light coding module is controlled by semiconductor cooling so that the temperature of the LCoS chip 6 is controlled within a set fluctuation range.

[0073] S2. The structured light coding module is used to image the object under test to obtain a multi-line binary grating image, and the depth of field of the structured light coding module is consistent on the imaging surface.

[0074] S3. Obtain the first-level coding map L based on the multi-line binarized raster image; then, use the complementary Gray code coding strategy to construct Gray code maps GC1 to GC5, and construct the second-level coding map K1 and the third-level coding map K2 based on Gray code maps GC1 to GC5. Finally, add the codes of the three-level coding maps L, K1, and K2 to obtain the final binarized coding map.

[0075] In some embodiments, S1 specifically includes the following steps:

[0076] S11. Perform thermal analysis on the structured light coding module using thermal analysis software (preferably Ansys) to determine the heating area and its temperature value under normal operation, and obtain the thermal analysis results; the analysis results are as follows. Figure 4 As shown, through Figure 4 It can be seen that the heat generation of the structured light coding module is mainly concentrated in two areas: one is the area where the light source 2 is located, and the other is the area where the LCoS chip 6 is located.

[0077] S12. Based on the thermal analysis results, the temperature of the LCoS chip 6 in the structured light coding module is controlled by using semiconductor cooling to keep the temperature of the LCoS chip 6 within the set fluctuation range.

[0078] In some embodiments, the LCoS chip 6 is a domestically produced LCoS chip 6.

[0079] In some embodiments, S2 specifically includes the following steps:

[0080] S21. Turn on light source 2, and light source 2 emits a beam of light;

[0081] S22, the light beam emitted by the light source 2 is converged by the condenser lens 31 and then passes through the aspherical collimating lens 32 to become parallel light;

[0082] S23, Parallel light passes through compound eye lens 33 and becomes multiple uniform parallel beams;

[0083] S24. The parallel light generated in S23 is transmitted, corrected, adjusted and distorted by the relay mirror 4 so that the beam transmitted by the relay mirror 4 matches the size of the LCoS chip 6.

[0084] S25. The beam transmitted from the relay mirror 4 is transmitted to the polarization beam splitter 5. The polarization beam splitter 5 reflects the beam with the set deflection angle onto the surface of the LCoS chip 6. The beams with other polarization angles are filtered by the polarization beam splitter 5. The LCoS chip 6 performs pixel-level control on the polarization angle of the reflected beam to realize structured light encoding and reflection.

[0085] S26. The beam emitted by the LCoS chip 6 is encoded and transmitted through the polarizing beam splitter 5 and projected onto the surface of the object being measured through the lens 7; a multi-line binary grating image is obtained; the width of the multi-line binary grating image is 2 pixels, and the intensity of the bright line of the pixel is 255, while the intensity of the other pixels is 0.

[0086] S27. By introducing the Sham projection principle to adjust the angle between the optical axes of the LCoS chip 6 and the lens 7, the depth of field of the structured light coding module on the imaging surface is made consistent. That is, the angle θ1 between the plane where the LCoS chip 6 is located and the optical axis of the lens 7, and the angle θ2 between the optical axis of the lens 7 and the normal direction of the imaging surface are equal. For details, please refer to [link / reference]. Figure 2 .

[0087] In some embodiments, S3 specifically includes the following steps:

[0088] S31. Shift the bright lines of the multiline binarized raster image one pixel to the right multiple times, row by row, to obtain a series of multiline binarized raster images; a series of multiline binarized raster images are as follows: Figure 5 As shown; the calculation formula for a series of multiline binarized raster images is: L = L1 + L2 + L3 + L4;

[0089] Among them, L1, L2, L3, and L4 are four different multiline binarized raster images;

[0090] S32. Arrange a series of multi-line binarized raster images to obtain the first-level coded image L;

[0091] S33. Using a complementary Gray code encoding strategy, construct Gray code maps GC1 to GC5, a total of 5 Gray code maps; wherein, from Gray code map GC1 to Gray code map GC5, the codeword width of the next Gray code map is half the codeword width of the previous Gray code map;

[0092] S34. Encode Gray code maps GC1 to GC4 to obtain the second-level coding map K1. The specific calculation formula for coding map K1 is as follows:

[0093] K1 = GC1 + GC2 + GC3 + GC4;

[0094] Wherein, GC2 and GC3 represent Gray code map GC2 and Gray code map GC3, respectively;

[0095] S35. Encode Gray code maps GC2 to GC5 to obtain the third-level coding map K2; the specific formula for calculating coding map K2 is as follows:

[0096] K2 = GC2 + GC3 + GC4 + GC5;

[0097] S36. The codes of the three levels of coding maps L, K1, and K2 are added together to obtain the final binary coding map C. The specific formula for calculating the binary coding map C is as follows:

[0098] C = L + K1 + K2.

[0099] See the example image of the binary coded image C. Figure 7 As shown.

[0100] This invention relies on the domestically produced LCoS chip 6 to obtain the final binarized encoded image, overcoming the inherent low contrast problem of the domestically produced LCoS chip 6. By optimizing the traditional encoding method, it significantly improves the spatial resolution and enhances the clarity and detail of the projected image.

[0101] In some embodiments, S33 specifically includes the following steps:

[0102] S331. First, project to obtain Gray code maps GC1 to GC4, a total of 4 Gray code maps; starting from Gray code map GC1 and ending at Gray code map GC4, the codeword width of each subsequent Gray code map is half the codeword width of the previous Gray code map; Gray code maps GC1 to GC4 are as follows... Figure 6 As shown, where Figure 6 As shown in Figure (a), from top to bottom are Gray code diagrams GC1 to GC4;

[0103] S332. Then project a Gray code image GC5 with a codeword width half that of Gray code image GC4. This yields a 5-bit Gray code image. This 5-bit Gray code image is used to construct 16 pixel periods, and each period has a unique corresponding Gray codeword. Gray code image GC5 is shown below. Figure 6 As shown in Figure (b).

[0104] Reference Figure 2 and Figure 3 In another aspect, the present invention provides a structured light coding module, which uses the above-described imaging method for imaging, including:

[0105] The housing 1 has an internal receiving space 11 and light inlet holes and imaging holes on both sides;

[0106] Light source 2 is fixedly installed on the outer wall of housing 1 close to the light inlet hole;

[0107] The parallel light imaging unit 3 is installed in the housing space 11 of the housing 1 and is used to convert the light emitted by the light source 2 into parallel light;

[0108] The relay mirror 4 is installed in the housing 11 and is used to optimize and transmit the light transmitted from the parallel light imaging unit 3.

[0109] The polarization beam splitter (PBS) 5 is obliquely installed in the receiving space 11 of the housing 1 to reflect the beam with a set deflection angle and then filter the beam outside the set deflection angle.

[0110] The LCoS chip 6 is attached to the inner wall of the housing 1 at a set Sham angle and is used to encode and reflect the beam reflected by the polarizing beam splitter 5.

[0111] Lens 7 is fixedly mounted on the outer wall of housing 1 close to the imaging aperture, and is used to transmit the light beam reflected by LCoS chip 6 so that the light beam illuminates the surface of the object being measured.

[0112] In some embodiments, the shell 1 is made of a low thermal expansion coefficient alloy material, such as Invar steel.

[0113] In some embodiments, refer to Figure 2 and Figure 3 The light source 2 is an LED light source, which is used to provide blue light.

[0114] In some embodiments, the structured light coding module further includes a heat sink, which is mounted on the light source 2 through a thermally conductive material to achieve heat conduction and dissipation of the light source 2;

[0115] The light source 2 is bonded to the outer wall of the housing 1 with heat-insulating adhesive to prevent the heat generated by the light source 2 from being conducted to the housing 1.

[0116] In some embodiments, the thermally conductive material is selected from graphene, a material with high thermal conductivity.

[0117] In summary, this invention performed thermal analysis on the structured light coding module using Ansys, obtained the thermal analysis results, and based on the thermal analysis results and optimized designs using insulating adhesives, graphene, etc., solved the temperature drift problem of the structured light coding module and controlled the heat generation of the LCoS chip 6 within an acceptable fluctuation range.

[0118] In some embodiments, refer to Figure 2 and Figure 3 The parallel light imaging unit 3 includes:

[0119] Condenser 31 is installed in the receiving space 11 of housing 1 and is located between light source 2 and relay mirror 4, for converging the light provided by light source 2;

[0120] Collimating lens 32 is installed in the receiving space 11 of housing 1 and is located between condenser lens 31 and relay lens 4, and is used to convert the light projected by condenser lens 31 into parallel light;

[0121] The compound eye lens 33 is installed in the receiving space 11 of the housing 1 and is located between the collimating lens 32 and the relay lens 4. It is used to optimize the parallel light projected by the collimating lens 32 to obtain parallel light with high uniformity.

[0122] In some embodiments, the parallel light imaging unit 3, the repeater mirror 4, and the polarizing beam splitter 5 are all made of quartz. Quartz has the characteristic of high thermal stability; by utilizing their high thermal stability, the interference of temperature fluctuations on the optical path collimation can be suppressed, ensuring that the structured light coding module can work stably for a long time in a wide temperature range.

[0123] The structured light coding module in this invention has the advantages of high-efficiency optical path transmission and high imaging accuracy. These advantages are mainly achieved by ensuring the accuracy of calculating the size, relative pose, and fabrication and assembly of each optical component (mainly including various lenses).

[0124] In addition, by effectively dissipating heat and controlling the temperature of the structured light coding module, the stability and reliability of the structured light coding module under different working conditions are ensured.

[0125] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An imaging method of a binary coded chart, characterized by, The method comprises the following steps: S1, controlling the temperature of the LCoS chip (6) in the structured light coding module by using the semiconductor refrigeration mode, so that the temperature of the LCoS chip (6) is controlled within a set fluctuation range; S2, imaging on the measured object by using the structured light coding module to obtain a multi-line binary grating image, and the structured light coding module has a consistent depth of field on the imaging surface; S3, obtaining a first-level coding image L according to the multi-line binary grating image; then constructing Gray code images GC1 to GC5 by using a complementary Gray code coding strategy, and constructing a second-level coding image K1 and a third-level coding image K2 according to the Gray code images GC1 to GC5; finally, adding the codes of the three levels of coding images L, K1 and K2 to obtain a final binary coding image; The S3 specifically comprises the following steps: S31, moving the bright lines of the multi-line binary grating image by one pixel position to the right multiple times to obtain a series of multi-line binary grating images; S32, arranging the series of multi-line binary grating images to obtain the first-level coding image L; S33, constructing the Gray code images GC1 to GC5 by using the complementary Gray code coding strategy, a total of 5 Gray code images; wherein, starting from the Gray code image GC1 to the Gray code image GC5, the code word width of the next Gray code image is half of that of the previous Gray code image; S34, encoding the Gray code images GC1 to GC4 to obtain the second-level coding image K1; S35, encoding the Gray code images GC2 to GC5 to obtain the third-level coding image K2; S36, adding the codes of the three levels of coding images L, K1 and K2 to obtain the final binary coding image C.

2. The imaging method of a binary coded pattern according to claim 1, characterized in that, The S2 specifically comprises the following steps: S21, turning on the light source (2), and the light source (2) emits a light beam; S22, the light beam emitted by the light source (2) is converged through the condenser lens (31) and then passes through the aspheric collimating lens (32) to become parallel light; S23, the parallel light becomes a plurality of uniform parallel light beams through the compound eye lens (33); S24, the parallel light generated in S23 is transmitted, corrected, adjusted and deformed and optimized through the relay lens (4), so that the light beam transmitted by the relay lens (4) matches the size of the LCoS chip (6); S25, the light beam transmitted by the relay lens (4) is transmitted to the polarization beam splitter prism (5), the polarization beam splitter prism (5) reflects the light beam with a set deflection angle to the surface of the LCoS chip (6), and the light beam with other polarization angles is filtered by the polarization beam splitter prism (5), the LCoS chip (6) performs pixel-level regulation on the polarization angle of the reflected light beam, realizes structured light coding and reflects; S26, the light beam coded and emitted by the LCoS chip (6) passes through the polarization beam splitter prism (5) and the lens (7) to project onto the surface of the measured object; a multi-line binary grating image is obtained. S27, the principle of the Sham projection is introduced to adjust the included angle between the optical axis of the LCoS chip (6) and the lens (7), so that the depth of field of the structured light coding module is consistent on the imaging surface, that is, the included angle θ1 between the plane where the LCoS chip (6) is located and the optical axis of the lens (7) is equal to the included angle θ2 between the optical axis of the lens (7) and the normal direction of the imaging surface.

3. The imaging method of a binary coded pattern according to claim 1, characterized in that, The calculation formula of the S3 coding pattern K1 is specifically as follows: K1=GC1+GC2+GC3+GC4; Wherein, GC2 and GC3 represent the gray code patterns GC2 and GC3 respectively; The calculation formula of the coding pattern K2 is specifically as follows: K2=GC2+GC3+GC4+GC5; The calculation formula of the binary coding pattern C is specifically as follows: C=L+K1+K2.

4. The imaging method of a binary coded pattern according to claim 3, characterized in that, The S33 specifically includes the following steps: S331, first, project to get gray code pattern GC1 to gray code pattern GC4, a total of 4 gray code patterns; from gray code pattern GC1 to gray code pattern GC4, the code word width of the next gray code pattern is half of the code word width of the last gray code pattern; S332, then project a gray code pattern GC5 with a code word width of half of the gray code pattern GC4, thus, a 5-bit gray code pattern is obtained, which is used to construct 16 pixel periods, and each period has a unique corresponding gray code word.

5. A structured light encoding module, comprising: Imaging using the imaging method of any one of claims 1 to 4, comprising: The shell (1) is internally formed with an accommodating space (11), and is provided with a light inlet hole and an imaging hole on both sides; The light source (2) is fixedly installed on the outer wall of the shell (1) close to the light inlet hole; The parallel light imaging unit (3) is installed in the accommodating space (11) of the shell (1) and is used to convert the light emitted by the light source (2) into parallel light; The relay lens (4) is installed in the accommodating space (11) of the shell (1) and is used to optimize and transmit the light transmitted by the parallel light imaging unit (3); The polarization light splitting prism (5) is installed in the accommodating space (11) of the shell (1) at an angle and is used to reflect the light beams with a set deflection angle and filter the light beams outside the set deflection angle; The LCoS chip (6) is attached to the inner wall of the shell (1) at a set Sham angle and is used to encode and reflect the light beams reflected by the polarization light splitting prism (5); The lens (7) is fixedly installed on the outer wall of the shell (1) close to the imaging hole and is used to transmit the light beams reflected by the LCoS chip (6) so that the light beams irradiate on the surface of the measured object.

6. The structured light coding module of claim 5, wherein, The material of the shell (1) is selected from invar steel.

7. The structured light encoding module of claim 5, wherein, The light source (2) is selected from an LED light source, and the LED light source is used to provide blue light.

8. The structured light coding module of claim 5, wherein, A heat sink is further included, which is installed on the light source (2) through a heat-conducting material to realize the conduction and heat dissipation of the heat of the light source (2); The light source (2) is bonded to the outer wall of the shell (1) through heat-insulating glue to avoid the conduction of the heat generated by the light source (2) to the shell (1).

9. The structured light coding module of claim 5, wherein, The parallel light imaging unit (3) comprises: A condenser lens (31) is installed in the accommodating space (11) of the shell (1) and is located between the light source (2) and the relay lens (4) and is used for converging the light provided by the light source (2); A collimator lens (32) is installed in the accommodating space (11) of the shell (1) and is located between the condenser lens (31) and the relay lens (4) and is used for converting the light projected by the condenser lens (31) into parallel light; An ommatidium lens (33) is installed in the accommodating space (11) of the shell (1) and is located between the collimator lens (32) and the relay lens (4) and is used for optimizing the parallel light projected by the collimator lens (32).

10. The structured light coding module of claim 5, wherein, The materials of the parallel light imaging unit (3), the relay lens (4) and the polarization beam splitter prism (5) are all quartz.

Images