A single-source lighting device that integrates electrically controllable switching of polarization and structured light.

Abstract

This invention relates to an electrically controllable switchable single-source lighting device integrating polarization and structured light, belonging to the field of optical lighting and 3D reconstruction technology. The device includes a polarization module, a moving mechanism, an electrically controlled motion mechanism, a Lyot depolarizing mirror, a striped structured light module, and a drive control module. It achieves electrically controlled switching between four lighting modes: vertically polarized light, horizontally polarized light, unpolarized white light, and polarized striped structured light. The drive control module also controls the voltage state of the TN-type liquid crystal cell and achieves N-step stripe phase shift through micro-phase shifting of the electrically controlled motion mechanism. This invention integrates multi-mode lighting into a single LED light source, achieving coaxial light source and natural data registration, and imparting structured light polarization characteristics, effectively suppressing interference from highly reflective surfaces. It is suitable for fields such as 3D scanning and machine vision.

Description

Technical Field

[0001] This invention relates to the field of optical lighting and three-dimensional reconstruction technology, specifically to an electrically controllable switchable single-source lighting device integrating polarization and structured light. Background Technology

[0002] Polarization 3D reconstruction and structured light 3D reconstruction are two mainstream 3D surface reconstruction technologies in 3D light field systems. Polarization 3D reconstruction requires the combination of three illumination modes: vertical polarization, horizontal polarization, and unpolarized white light. The introduction of polarization characteristics can effectively improve its resistance to specular highlights. Structured light 3D reconstruction, on the other hand, relies on structured light projection of various patterns.

[0003] In existing 3D light field systems, polarization illumination units typically consist of three independent LED regions, with polarizers placed in front of the LEDs to achieve two polarization states of light output. Only one illumination mode is used at any given time, leading to problems such as large light source size, inconvenience for compact system layout, and waste of circuit and component resources. Structured light reconstruction requires a separate projection light source system, which is not sourced from the polarization illumination unit's light source and has a non-coaxial optical path. This not only further increases the system size and cost but also makes it difficult to naturally register the two types of reconstructed data, increasing the complexity of data fusion. Furthermore, traditional structured light lacks polarization characteristics, making it prone to losing fringe information when reconstructing on highly reflective surfaces, thus reducing reconstruction accuracy.

[0004] To address the aforementioned issues, there is an urgent need to develop an illumination device that integrates polarized, unpolarized, and structured light illumination modes into a single-area LED light source, and can electronically switch between various modes and polarization states to meet the requirements of polarized 3D reconstruction and structured light 3D reconstruction. Summary of the Invention

[0005] The purpose of this invention is to address the problems raised in the background art by providing an electrically controllable switchable single-source lighting device integrating polarization and structured light. It includes a fixed optical assembly arranged coaxially, a moving mechanism for switching lighting modes, an electrically controlled motion mechanism connected to the moving mechanism, and a drive control module electrically connected to both the fixed optical assembly and the electrically controlled motion mechanism. Along the light emission direction, the fixed optical assembly consists of a white LED, a collimating lens, a fixed polarizer, and a TN-type liquid crystal cell arranged sequentially. The moving mechanism for switching lighting modes is an integrated moving mechanism mounted on a horizontal guide rail. The drive control module uses commercially available components and control schemes to achieve automated switching and phase shift control of various lighting modes.

[0006] A single-source lighting device integrating polarization and structured light includes an electrically controlled motion mechanism 1, a Lyot depolarizing mirror 2, a moving mechanism 3, a polarization module 4, and a striped structured light module 5. Among them, the Lyot depolarizing mirror 2 and the striped structured light module 5 are respectively installed on both sides of the moving mechanism 3; The polarization module 4 is fixed on the light source substrate 7 and is used to provide the light source; The electrically controlled motion mechanism 1 is driven to connect with the moving mechanism 3; The moving mechanism 3 can move horizontally relative to the polarization module 4 under the drive of the electronically controlled motion mechanism 1, so as to realize the corresponding cooperation between the Lyot depolarizing mirror 2, the striped structured light module 5 and the light output end of the polarization module 4, and complete the switching of different illumination modes. The Lyot depolarizing mirror 2, the striped structured light module 5, and the moving mechanism 3 have their upper and lower surfaces flush. The assembly structure ensures that the depolarizing mirror 2 is in close contact with the light output end of the polarizing module 4 when it is moved into the optical path. This close contact is achieved by the assembly, ensuring that there are basically no gaps and no light leakage, without any specific distance limit.

[0007] The electronically controlled motion mechanism 1 is a linear stepper motor, whose output end is fixedly connected to the moving mechanism 3. It can realize the dual functions of coarse motion switching and micro motion phase shifting: coarse motion switching is used to drive the moving mechanism 3 to move back and forth between three workstations to realize the switching of lighting modes; micro motion phase shifting is used to drive the striped structured light module 5 to move precisely along the optical axis to realize N-step striped phase shifting.

[0008] Optionally, the polarization module 4 includes an LED 4-1, a collimating lens 4-2, a polarizer 4-3, and a TN-type liquid crystal cell 4-4 connected coaxially in sequence. Optionally, LED 4-1 is a high-brightness surface-mount white LED, serving as the sole light-emitting unit of the device. Its light-emitting side is attached to a collimating lens 4-2, and the distance between the collimating lens 4-2 and LED 4-1 is the focal length of the collimating lens, ensuring that the unpolarized white light emitted by LED 4-1 is converted into parallel light after collimation. Optionally, the distance L between the collimating lens 4-2 and the LED 4-1 satisfies 0.8f≤L≤1.2f, where f is the focal length of the collimating lens 4-2; Optionally, polarizer 4-3 is a horizontally or vertically oriented linear polarizer used to convert parallel light into linearly polarized light; The TN-type liquid crystal cell 4-4 is a twisted nematic liquid crystal cell. Its initial orientation is adapted to the transmission direction of the polarizer 3. When a voltage is applied, the polarization direction is maintained at 0° rotation. When the voltage is disconnected, the polarization direction is rotated by 90°. The components of the polarization module 4 are bonded together into an integrated structure with high light transmittance optical adhesive to reduce optical path assembly errors.

[0009] Optionally, the moving mechanism 3 is an integrated structure that is slidably connected to the guide rail 6. The guide rail is arranged perpendicular to the optical axis of the polarization module 4, and its limiting accuracy is adapted to the moving accuracy of the electronically controlled motion mechanism 1. Optionally, the moving mechanism 3 includes a moving base, a guide rail mating structure, and a motion mechanism connecting end. The moving mechanism 3 is also connected to the electrically controlled motion mechanism 1, which pushes it to move along the guide rail. Optionally, the moving mechanism 3 is arranged with three stations in sequence along the horizontal direction. The left station is fixed with a Lyot depolarizing mirror, which is used to convert linearly polarized light into unpolarized white light when it is moved into the optical path. The middle station is a blank station, which is used for the optical path to pass through and output horizontal or vertical linearly polarized light. The right station is fixed with a striped structured light module 5. The striped structured light module 5 consists of a physical striped grating and a projection lens from the inside to the outside, which is used to convert polarized parallel light into polarized striped structured light and achieve clear projection.

[0010] Optionally, the aperture of the Lyot depolarizing mirror is not less than the output aperture of the polarization module 4, ensuring that most of the linearly polarized light is incident and depolarized.

[0011] Optionally, the aperture of the Lyot depolarizing mirror covers the light-emitting area of ​​the white LED light source; The aperture of the Lyot depolarizing mirror is larger than the output end of polarization module 4. Optionally, the device also includes a drive control module, which is electrically connected to LED4-1, TN-type LCD cell 4-4 and electric motion mechanism 1, and can output adjustable working voltage and precise pulse signal to realize the automatic control of each device.

[0012] In this invention, the three stations on the moving mechanism 3 are used to achieve specific illumination on the basic polarized light. The left and right stations are respectively fixed with Lyot depolarizing mirrors and striped structured light modules. The moving mechanism 3 is controlled by the electronically controlled motion mechanism 1 to move along the guide rail and align one of the three stations with the light output end of the polarization module 4.

[0013] Optionally, the electronically controlled motion mechanism 1 is a linear stepper motor, whose output end is fixedly connected to the moving mechanism 3, and can drive the moving mechanism 3 to complete coarse motion switching and micro motion phase shifting operations along the horizontal guide rail; Optionally, the aperture of the Lyot depolarizing mirror covers the light-emitting area of ​​the white LED light source; The aperture of the Lyot depolarizing mirror is larger than the output end of polarization module 4. For example, the aperture of the Lyot depolarizing filter is 10mm~22mm; Optionally, the device also includes a drive control module, which is electrically connected to LED4-1, TN-type LCD cell 4-4 and electric motion mechanism 1 respectively, and can output adjustable working voltage and precise pulse signal to realize the automatic control of each device; Furthermore, the electronically controlled motion mechanism is preferably a linear stepper motor, which can realize dual functions of coarse motion switching and micro-phase shifting: coarse motion switching is used to drive mechanism A to move back and forth between three stations to realize the switching of lighting modes; micro-phase shifting is used to drive the structured light projection unit to move precisely along the optical axis to realize N-step fringe phase shifting, which meets the phase calculation requirements of structured light three-dimensional reconstruction.

[0014] In one embodiment of the present invention, when vertically polarized light needs to be output, the drive control module outputs a control signal to the electronically controlled motion mechanism 1, driving the moving mechanism 3 to move along the horizontal guide rail, so that the middle blank station of the moving mechanism 3 is aligned with the light-emitting end of the polarization module 4; the drive control module applies a predetermined working voltage to the TN-type liquid crystal cell 4, and at the same time activates LED 4-1. The unpolarized white light emitted by LED 4-1 is collimated into parallel light by the collimating lens 2, and then converted into linearly polarized light by the polarizer 3. The polarization direction of the linearly polarized light remains unchanged after passing through the TN-type liquid crystal cell 4 in the powered state, and finally vertically polarized parallel light is output. Optionally, the voltage value is determined according to the actual characteristics of the TN type liquid crystal cell 4-4, and is generally 2~3V; The polarization module 4 is fixed in the light source substrate to emit polarized light. A horizontal guide rail perpendicular to the optical axis is fixed on the light source substrate. The moving mechanism 3 can cooperate with the guide rail and move on the guide rail so that the station can be aligned with the light output end of the polarization module 4 through the movement.

[0015] Optionally, the Lyot depolarizing mirror 3 or the striped structured light module 5 can be moved to align with the light-emitting end of the polarization module; and when the blank station is aligned, it is only necessary to ensure that the other two stations do not obstruct the light output of the polarization module 4. When horizontally polarized light needs to be output, the drive control module drives the moving mechanism 3 to align the middle blank station with the light-emitting end of the polarization module 4, keeping the optical path straight; the voltage applied to the TN-type liquid crystal cell 4 is disconnected, and the liquid crystal molecules return to their 90° twisted alignment; LED 4-1 is activated, and the linearly polarized light formed by collimation and polarization of the unpolarized white light rotates 90° in polarization direction after passing through the de-energized TN-type liquid crystal cell 4, finally outputting horizontally polarized parallel light; When unpolarized white light needs to be output, the drive control module drives the moving mechanism 3 to move along the horizontal guide rail, so that the Lyot depolarizing mirror 2 is precisely moved into the optical path and closely attached to the light-emitting side of the polarization module 4; the voltage state of the TN type liquid crystal cell 4 is not limited, the LED4-1 is activated, and the unpolarized white light is collimated, polarized and rotated by the polarization module 4 to form linearly polarized light in a single direction. After the linearly polarized light is incident on the Lyot depolarizing mirror 2, it is converted into unpolarized white light by the depolarization effect and then emitted. The drive control mechanism 1 is connected to the moving mechanism 3 and can control the moving mechanism 3 to move along the horizontal guide rail. On the one hand, the drive control mechanism 1 can move the moving mechanism 3 a specified distance. On the other hand, limit structures are set at the ends of both sides of the horizontal guide rail to more accurately limit the movement range of the moving mechanism 3. In this invention, the polarization module 4 is mounted on the light source substrate, with its light-emitting end flush with the mounting surface of the light source substrate. The mounting surface of the light source substrate is flat. After the moving mechanism 3 is assembled with the guide rail, it basically fits the surface of the light source substrate. The Lyot depolarizing mirror 2 and the striped structured light module 5 are flush with the upper and lower surfaces of the moving mechanism 3. The assembly structure ensures that the depolarizing mirror 2 is in close contact with the light-emitting end of the polarization module 4 when it moves into the optical path. This close contact is achieved by the assembly, ensuring that there are basically no gaps and no light leakage. There is no specific distance limit.

[0016] When it is necessary to output polarized stripe structured light and achieve N-step phase shift, the drive control module drives the moving mechanism 3 to align the light-emitting end of the stripe structured light module 5 with that of the polarization module 4; according to actual needs, the power-on and power-off state of the TN-type liquid crystal cell 4 is controlled so that the polarization module 4 outputs horizontally or vertically polarized parallel light. This polarized parallel light is incident perpendicularly on the stripe grating 5-1 and forms polarized stripe light through grating diffraction; the polarized stripe light is incident on the projection lens 5-2 and projected onto the surface of the object at the target distance to form polarized stripe structured light. In this invention, the Lyot depolarizing mirror 2 and the striped structured light module 5 are arranged in parallel on the moving mechanism. The two and the blank workstation are not simultaneously in the optical path of the polarization module. Instead, the moving mechanism 3 moves along the guide rail to achieve the selection of one pair of positive optical axes according to different functional needs.

[0017] When the moving mechanism 3 moves the striped structured light module 5 to be aligned with the light output end of the polarization module 4, the polarized parallel light output by the polarization module 4 is incident perpendicularly onto the striped grating. Since the guide rail itself is arranged perpendicular to the optical axis, the moving mechanism 3 is assembled with the guide rail, and the mechanical assembly positioning and guide rail guiding accuracy can meet the requirements of perpendicular incidence.

[0018] The drive control module selects the N-step phase shift mode according to the requirements of structured light 3D reconstruction, obtains the number of motor movement pulses required for each phase shift, and outputs a precise pulse signal to the electric control motion mechanism 1 to drive the striped structured light module 5 to make a small and precise movement along the horizontal guide rail, thereby realizing the N-step phase shift of polarized striped structured light. By acquiring the stripe images under each phase shift state, the phase calculation requirements of structured light 3D reconstruction can be met.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention integrates four lighting modes into a single area LED light source, replacing the traditional three independent LED area design of polarized lighting and the independent projection light source design of structured light, which greatly reduces the size of the light source module and avoids waste of circuit and component resources. (2) This invention imparts polarization characteristics to striped structured light, which breaks through the technical limitations of traditional structured light that has no polarization characteristics and is easily affected by high light interference. It effectively solves the problem of stripe information loss during reconstruction of highly reflective surfaces and significantly improves the accuracy and robustness of structured light three-dimensional reconstruction. (3) The present invention realizes that the light source and optical path of polarization and structured light reconstruction are the same, so that the two types of reconstruction data are naturally registered, which helps to reduce the algorithm complexity of multimodal three-dimensional reconstruction data fusion and improve reconstruction efficiency; and the device is an independent design, which is easy to integrate and replace with existing three-dimensional light field systems. (4) The same electric control motion mechanism of the present invention realizes the dual functions of mode switching and phase shift, which improves the utilization rate of the mechanism and the control integration.

[0020] This invention can be integrated into handheld 3D scanners, automated quality inspection systems, medical imaging surface reconstruction equipment, etc., and is particularly suitable for high-precision 3D reconstruction of complex surfaces such as highly reflective industrial parts (such as metals and mirrors) and moist biological tissues. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0022] Figure 1 This is a schematic diagram of the overall structure of an electrically controllable switchable single-source lighting device integrating polarization and structured light in an embodiment of the present invention. Figure 2 This is a schematic diagram of the polarization module in an embodiment of the present invention; Figure 3 This is a schematic diagram of the striped structured light module in an embodiment of the present invention; Reference numerals: 1. Electrically controlled motion mechanism; 2. Lyot depolarizing mirror; 3. Moving mechanism; 4. Polarization module; 5. Striped structured light module; 6. Guide rail; 7. Light source substrate; 4-1, LED; 4-2, Collimating lens; 4-3, Polarizer; 4-4, TN type liquid crystal cell; 5-1. Striped grating; 5-2. Projection lens. Detailed Implementation

[0023] To better understand the above-described objectives, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Furthermore, the present invention can be implemented in other ways different from those described herein; therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0024] A specific embodiment of the present invention, such as Figure 1-3 A single-source lighting device integrating polarization and structured light is disclosed, including an electrically controlled motion mechanism 1, a Lyot depolarizing mirror 2, a moving mechanism 3, a polarization module 4, and a striped structured light module 5. Among them, the Lyot depolarizing mirror 2 and the striped structured light module 5 are respectively installed on both sides of the moving mechanism 3; The polarization module 4 is fixed on the light source substrate 7 and is used to provide the light source; The electrically controlled motion mechanism 1 is driven to connect with the moving mechanism 3; The moving mechanism 3 can move horizontally relative to the polarization module 4 under the drive of the electronically controlled motion mechanism 1, so as to realize the corresponding cooperation between the Lyot depolarizing mirror 2, the striped structured light module 5 and the light output end of the polarization module 4, and complete the switching of different illumination modes. The Lyot depolarizing mirror 2, the striped structured light module 5, and the moving mechanism 3 have their upper and lower surfaces flush. The assembly structure ensures that the depolarizing mirror 2 is in close contact with the light output end of the polarizing module 4 when it is moved into the optical path. This close contact is achieved by the assembly, ensuring that there are basically no gaps and no light leakage, without any specific distance limit.

[0025] Optionally, the polarization module 4 is a fixed optical component, wherein each component is sequentially bonded together by optical adhesive to form an integrated optical component, thereby reducing the optical path length and assembly error.

[0026] Optionally, the polarization module 4 includes an LED 4-1, a collimating lens 4-2, a polarizer 4-3, and a TN-type liquid crystal cell 4-4 connected coaxially in sequence. LED 4-1 is a high-brightness surface-mount white LED, serving as the sole light-emitting unit of the device. Collimating lens 4-2 is attached to its light-emitting side, and the distance between collimating lens 4-2 and LED 4-1 is the focal length of the collimating lens, ensuring that the unpolarized white light emitted by LED 4-1 is converted into parallel light after collimation. Optionally, the distance L between the collimating lens 4-2 and the LED 4-1 satisfies 0.8f≤L≤1.2f, where f is the focal length of the collimating lens 4-2; Preferably, 0.9f≤L≤1.1f.

[0027] Optionally, polarizer 4-3 is a horizontally or vertically oriented linear polarizer used to convert parallel light into linearly polarized light; The TN-type liquid crystal cell 4-4 is a twisted nematic liquid crystal cell. Its initial orientation is adapted to the transmission direction of the polarizer 3. When a voltage is applied, the polarization direction is maintained at 0° rotation. When the voltage is disconnected, the polarization direction is rotated by 90°. The components of the polarization module 4 are bonded together into an integrated structure with high light transmittance optical adhesive to reduce optical path assembly errors.

[0028] Optionally, the moving mechanism 3 is an integrated structure that is slidably connected to the guide rail 6. The guide rail is arranged perpendicular to the optical axis of the polarization module 4, and its limiting accuracy is adapted to the moving accuracy of the electronically controlled motion mechanism 1. Optionally, the guide rail 6 is fixedly connected to the light source substrate 7 and cooperates with the moving mechanism 3, so that the moving mechanism 3 can move horizontally perpendicular to the optical axis.

[0029] Optionally, the moving mechanism 3 includes a moving base, a guide rail mating structure, and a motion mechanism connecting end. The moving mechanism 3 is also connected to the electrically controlled motion mechanism 1, which pushes it to move along the guide rail. The movable base is a rectangular frame, and the guide rail can be a sliding groove. The moving mechanism 3 has three stations set up in sequence along the horizontal direction. The left station is fixed with a Lyot depolarizing mirror, which is used to convert linearly polarized light into unpolarized white light when it is moved into the optical path. The middle station is a blank station, which is used for the optical path to pass through and output horizontal or vertical linearly polarized light. The right station is fixed with a striped structured light module 5. The striped structured light module 5 consists of a physical striped grating and a projection lens from the inside to the outside, which is used to convert polarized parallel light into polarized striped structured light and achieve clear projection.

[0030] In this invention, the three stations on the moving mechanism 3 are used to achieve specific illumination on the basic polarized light. The left and right stations are respectively fixed with Lyot depolarizing mirrors and striped structured light modules. The moving mechanism 3 is controlled by the electronically controlled motion mechanism 1 to move along the guide rail and align one of the three stations with the light output end of the polarization module 4.

[0031] Furthermore, the aperture of the Lyot depolarizing mirror is not less than the aperture of the polarization module 4, ensuring that most of the linearly polarized light is incident and depolarized.

[0032] Optionally, the electronically controlled motion mechanism 1 is a linear stepper motor, whose output end is fixedly connected to the moving mechanism 3, and can drive the moving mechanism 3 to complete coarse motion switching and micro motion phase shifting operations along the horizontal guide rail; Optionally, the aperture of the Lyot depolarizing mirror covers the light-emitting area of ​​the white LED light source; The aperture of the Lyot depolarizing mirror is larger than the output end of polarization module 4. For example, the aperture of the Lyot depolarizing filter is 10mm~22mm; Optionally, the device also includes a drive control module, which is electrically connected to LED4-1, TN-type LCD cell 4-4 and electric motion mechanism 1 respectively, and can output adjustable working voltage and precise pulse signal to realize the automatic control of each device; Furthermore, the electronically controlled motion mechanism is preferably a linear stepper motor, which can realize dual functions of coarse motion switching and micro-phase shifting: coarse motion switching is used to drive mechanism A to move back and forth between three stations to realize the switching of lighting modes; micro-phase shifting is used to drive the structured light projection unit to move precisely along the optical axis to realize N-step fringe phase shifting, which meets the phase calculation requirements of structured light three-dimensional reconstruction.

[0033] In one embodiment of the present invention, when vertically polarized light needs to be output, the drive control module outputs a control signal to the electronically controlled motion mechanism 1, driving the moving mechanism 3 to move along the horizontal guide rail, so that the middle blank station of the moving mechanism 3 is aligned with the light-emitting end of the polarization module 4; the drive control module applies a predetermined working voltage to the TN-type liquid crystal cell 4, and at the same time activates LED 4-1. The unpolarized white light emitted by LED 4-1 is collimated into parallel light by the collimating lens 2, and then converted into linearly polarized light by the polarizer 3. The polarization direction of the linearly polarized light remains unchanged after passing through the TN-type liquid crystal cell 4 in the energized state, and finally vertically polarized parallel light is output. Optionally, the voltage value is determined according to the actual characteristics of the TN type liquid crystal cell 4-4, and is 2~3V; The polarization module 4 is fixed in the light source substrate 7 to emit polarized light. A guide rail perpendicular to the optical axis is fixed on the light source substrate 7. The moving mechanism 3 can cooperate with the guide rail 6 and move on the guide rail so that the station can be aligned with the light output end of the polarization module 4 through the movement.

[0034] Optionally, adjust the Lyot depolarizing mirror 3 or the striped structured light module 5 to be aligned with the light output end of the polarization module; and when the blank station is aligned, it is only necessary to ensure that the light output from the polarization module 4 is not obstructed by the other two stations.

[0035] When horizontally polarized light needs to be output, the drive control module drives the moving mechanism 3 to align the middle blank station with the light output end of the polarization module 4, keeping the optical path straight; the voltage applied to the TN-type liquid crystal cell 4 is disconnected, and the liquid crystal molecules return to their 90° twisted alignment; LED 4-1 is activated, and the linearly polarized light formed by collimation and polarization of the unpolarized white light rotates 90° in polarization direction after passing through the TN-type liquid crystal cell 4 in a de-energized state, and finally outputs horizontally polarized parallel light; When unpolarized white light needs to be output, the drive control module drives the moving mechanism 3 to move along the horizontal guide rail, so that the Lyot depolarizing mirror 2 is precisely moved into the optical path and closely attached to the light-emitting side of the polarization module 4; the voltage state of the TN type liquid crystal cell 4 is not limited, the LED4-1 is activated, and the unpolarized white light is collimated, polarized and rotated by the polarization module 4 to form linearly polarized light in a single direction. After the linearly polarized light is incident on the Lyot depolarizing mirror 2, it is converted into unpolarized white light by the depolarization effect and then emitted. The drive control mechanism 1 is connected to the moving mechanism 3 and can control the moving mechanism 3 to move along the horizontal guide rail. On the one hand, the drive control mechanism 1 can move the moving mechanism 3 a specified distance. On the other hand, limit structures are set at the ends of both sides of the horizontal guide rail to more accurately limit the movement range of the moving mechanism 3. In this invention, the polarization module 4 is mounted on the light source substrate, with its light-emitting end flush with the mounting surface of the light source substrate. The mounting surface of the light source substrate is flat. After the moving mechanism 3 is assembled with the guide rail, it basically fits the surface of the light source substrate. The Lyot depolarizing mirror 2 and the striped structured light module 5 are flush with the upper and lower surfaces of the moving mechanism 3. The assembly structure ensures that the depolarizing mirror 2 is in close contact with the light-emitting end of the polarization module 4 when it moves into the optical path. This close contact is achieved by the assembly, ensuring that there are basically no gaps and no light leakage. There is no specific distance limit.

[0036] When it is necessary to output polarized stripe structured light and achieve N-step phase shift, the drive control module drives the moving mechanism 3 to align the light-emitting end of the stripe structured light module 5 with that of the polarization module 4; according to actual needs, the power-on and power-off state of the TN-type liquid crystal cell 4 is controlled so that the polarization module 4 outputs horizontally or vertically polarized parallel light. This polarized parallel light is incident perpendicularly on the stripe grating 5-1 and forms polarized stripe light through grating diffraction; the polarized stripe light is incident on the projection lens 5-2 and projected onto the surface of the object at the target distance to form polarized stripe structured light. In this invention, the Lyot depolarizing mirror 2 and the striped structured light module 5 are arranged in parallel on the moving mechanism. The two and the blank workstation are moved along the guide rail by the moving mechanism 3 to realize the selection of one pair of positive optical axes according to different functional needs.

[0037] When the moving mechanism 3 moves the striped structured light module 5 to be aligned with the light output end of the polarization module 4, the polarized parallel light output by the polarization module 4 is incident perpendicularly onto the striped grating. Since the guide rail itself is arranged perpendicular to the optical axis, the moving mechanism 3 is assembled with the guide rail, and the mechanical assembly positioning and guide rail guiding accuracy can meet the requirements of perpendicular incidence.

[0038] The working principle of this invention is as follows: the drive control module outputs control signals to regulate the electric motion mechanism to drive the moving mechanism to move horizontally along the guide rail, so that different positions of the moving mechanism correspond to the light output end of the polarization module. Combined with the voltage regulation of the TN type liquid crystal cell, the switching of four illumination modes is realized: vertically polarized light, horizontally polarized light, unpolarized white light, and polarized stripe structured light. When polarized stripe structured light needs to be output, the micro-phase shift function of the electric motion mechanism is used to realize N-step stripe phase shift, which meets the phase calculation requirements of structured light three-dimensional reconstruction.

[0039] The drive control module selects the N-step phase shift mode according to the requirements of structured light 3D reconstruction, obtains the number of motor movement pulses required for each phase shift, and outputs a precise pulse signal to the electric control motion mechanism 1 to drive the striped structured light module 5 to make a small and precise movement along the horizontal guide rail, thereby realizing the N-step phase shift of polarized striped structured light. By acquiring the stripe images under each phase shift state, the phase calculation requirements of structured light 3D reconstruction can be met.

[0040] N The expression for the distance moved by the phase shift is:

[0041] in, α The step angle, P For the lead screw, T Z is the period of the striped grating, Z is the set of integers in mathematical symbols, n≥1 means that n is an integer not less than 1, and N is the number of pulses that need to be provided to the motor for each phase shift.

[0042] Furthermore, the focal length of the projection lens f Object distance u Image distance v It satisfies the Gaussian projection formula, and its expression is:

[0043] The magnification of the striped grating after projection through the projection lens M The expression is:

[0044] This invention integrates polarized illumination and polarized structured light projection into a single-area LED light source. Through electrically controlled polarization adjustment of fixed optical components and mechanical switching of switchable functional modules, it achieves an integrated design with multiple illumination modes. Simultaneously, it utilizes the same electrically controlled motion mechanism to complete mode switching and structured light phase shifting, achieving dual reuse of the mechanism's functions. The polarized striped structured light output by this invention possesses polarization characteristics, effectively suppressing high-brightness interference from highly reflective surfaces and improving the accuracy of structured light 3D reconstruction. Furthermore, the four illumination modes are coaxial and originate from the same source, allowing for natural registration of polarized 3D reconstruction normal vector data and structured light 3D reconstruction depth data, simplifying the optical calibration and data fusion process.

[0045] The integrated polarization and polarization structured light electrically controllable switchable single-source illumination device provided by this invention has the advantages of compact structure, high resource utilization, convenient control, and strong resistance to high light. It is suitable for the dense arrangement of light sources in three-dimensional light field systems and has broad application prospects in three-dimensional scanning, machine vision, computer graphics and other fields.

[0046] Example 1 A single-source lighting device integrating polarization and structured light includes an electrically controlled motion mechanism 1, a Lyot depolarizing mirror 2, a moving mechanism 3, a polarization module 4, and a striped structured light module 5. The Lyot depolarizing mirror 2 and the striped structured light module 5 are respectively mounted on opposite sides of the moving mechanism 3; the polarization module 4 is fixed to the light source substrate 7; the electrically controlled motion mechanism 1 is driven to the moving mechanism 3; the moving mechanism 3 can move horizontally relative to the polarization module 4 under the drive of the electrically controlled motion mechanism 1.

[0047] Polarization module 4 includes an LED 4-1, a collimating lens 4-2, a vertically oriented linear polarizer, and a TN-type liquid crystal cell 4-4 connected coaxially in sequence; the components are bonded together with optical ultraviolet adhesive. LED4-1 model: CREE XHP70.2, white light, collimating lens 4-2 focal length f=15mm; TN type liquid crystal cell 4-4 is a twisted nematic phase, response time <10ms; the distance between the collimating lens and the LED L=15mm, i.e., 1.0f. The TN type liquid crystal cell maintains polarization when a 2.5V voltage is applied, and rotates 90° when disconnected. The moving mechanism 3 is an aluminum alloy rectangular frame with a sliding groove at the bottom, which slides in conjunction with the horizontal guide rail 6 fixed on the light source substrate 7. The moving mechanism 3 has three stations arranged sequentially along the moving direction: the left station is fixed with a Lyot depolarizing mirror 2 with a light-passing aperture of 15mm and a thickness of 3mm; the middle station is empty; and the right station is fixed with a striped structured light module 5. The striped structured light module 5 includes a sinusoidal grating of chrome-coated glass with a period of 100μm and a projection lens with a focal length of 25mm and a diameter of 12mm. Assembly ensures that the gap between the Lyot depolarizing mirror and the light-emitting end of the polarization module is ≤0.05mm when the Lyot depolarizing mirror is moved into the optical path.

[0048] The electrically controlled motion mechanism 1 is a linear stepper motor with a step angle of 1.8°, a lead screw of 2mm, and a movement of 0.01mm per pulse. Its output shaft is fixedly connected to the moving mechanism 3. The drive control module uses an STM32 microcontroller, which outputs an adjustable voltage of 0~5V to the TN LCD cell, outputs PWM pulses to the stepper motor, and controls the constant current drive of the LED.

[0049] Work process: Output vertically polarized light: The drive control module controls the stepper motor to align the intermediate blank station with the optical path; applies 2.5V voltage to the TN LCD cell; and lights the LED. Output vertically polarized parallel light; Output horizontally polarized light: Align the blank workstation; disconnect the TN LCD cell voltage; turn on the LED. Output horizontally polarized parallel light; Outputting unpolarized white light: A stepper motor drives the moving mechanism to move to the left, causing the Lyot depolarizing mirror to enter the optical path and be close to the light-emitting end of the polarization module; the TN LCD cell can be in any state; the LED is lit. Linearly polarized light is depolarized and then output as unpolarized white light. Outputting polarized striped structured light and phase shifting: A stepper motor drives the moving mechanism to move to the right, aligning the striped structured light module with the optical path; the TN liquid crystal cell is powered on or off as needed, outputting vertically or horizontally polarized parallel light, which forms polarized striped structured light after passing through a grating and projection lens. For four-step phase shifting, the drive control module calculates the required movement distance T / 4 = 25 μm per step, corresponding to 25 μm ÷ 0.01 μm / pulse = 2500 pulses. 0, 2500, 5000, and 7500 pulses are output sequentially to achieve four-step phase shifting. Phase decoding is achieved by acquiring four images.

[0050] Example 2 The implementation is essentially the same as in Example 1, except that the distance between the collimating lens and the LED is L = 13.5 mm (0.9f). The Lyot depolarizing mirror has a 20 mm aperture. The fringe grating has a period of 150 μm and uses a polymer thin-film grating. The N-step phase shift uses a three-step phase shift, with each step moving a distance of T / 3 = 50 μm and 5000 pulses.

[0051] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A single-source lighting device integrating polarization and structured light, comprising an electrically controlled motion mechanism (1), a Lyot depolarizing mirror (2) moving mechanism (3), a polarization module (4), and a striped structured light module (5). The Lyot depolarizing mirror (2) and the striped structured light module (5) are respectively installed on both sides of the moving mechanism (3); The polarization module (4) is fixed on the light source substrate (7) and is used to provide the light source; The electrically controlled motion mechanism (1) is driven to connect with the moving mechanism (3); The moving mechanism (3) can move horizontally relative to the polarization module (4) under the drive of the electronically controlled motion mechanism (1), so as to realize the corresponding cooperation between the Lyot depolarizing mirror (2), the striped structured light module (5) and the light output end of the polarization module (4) to complete the switching of different lighting modes. The upper and lower surfaces of the Lyot depolarizing mirror (2), the striped structured light module (5), and the moving mechanism (3) are flush. The assembly structure ensures that the depolarizing mirror (2) is in close contact with the light output end of the polarizing module (4) when it is moved into the optical path. The electric motion mechanism (1) is a linear stepper motor, whose output end is fixedly connected to the moving mechanism (3), and can realize the dual functions of coarse motion switching and micro motion phase shift: coarse motion switching is used to drive the moving mechanism (3) to move back and forth between three workstations to realize the switching of lighting modes; micro motion phase shift is used to drive the striped structured light module (5) to move precisely along the optical axis to realize N-step striped phase shift.

2. The single-source illumination device integrating polarization and structured light according to claim 1, characterized in that, The polarization module (4) includes an LED (4-1), a collimating lens (4-2), a polarizer (4-3), and a TN-type liquid crystal cell (4-4) connected coaxially in sequence. LED (4-1) is a high-brightness surface-mount white LED, with a collimating lens (4-2) attached to its light-emitting side, and the distance between the collimating lens (4-2) and LED (4-1) is the focal length of the collimating lens.

3. The single-source illumination device integrating polarization and structured light according to claim 2, characterized in that, The distance L between the collimating lens (4-2) and the LED (4-1) satisfies 0.8f≤L≤1.2f, where f is the focal length of the collimating lens (4-2).

4. The single-source illumination device integrating polarization and structured light according to claim 2, characterized in that, Polarizer (4-3) is a horizontally or vertically oriented linear polarizer used to convert parallel light into linearly polarized light.

5. The single-source illumination device integrating polarization and structured light according to claim 2, characterized in that, The TN-type liquid crystal cell (4-4) is a twisted nematic liquid crystal cell. Its initial orientation is adapted to the transmission direction of the polarizer (3). When the voltage is applied, the polarization direction is kept at 0° rotation. When the voltage is disconnected, the polarization direction is rotated by 90°. The components of the polarization module (4) are bonded together into an integrated structure by high transmittance optical adhesive.

6. The single-source illumination device integrating polarization and structured light according to claim 1, characterized in that, The moving mechanism (3) has three stations set up in sequence along the horizontal direction. The left station is fixed with a Lyot depolarizing mirror, which is used to convert linearly polarized light into unpolarized white light when it is moved into the optical path. The middle station is a blank station, which is used for the optical path to pass through and output horizontal or vertical linearly polarized light. The right station is fixed with a striped structured light module (5). The striped structured light module (5) consists of a physical striped grating and a projection lens from the inside to the outside, which is used to convert polarized parallel light into polarized striped structured light and achieve clear projection.

7. The single-source illumination device integrating polarization and structured light according to claim 1, characterized in that, The polarization module (4) is fixed in the light source substrate, and the moving mechanism (3) cooperates with the guide rail fixed on the light source substrate. It can be controlled by the electric motion mechanism (1) to move along the guide rail.

8. The single-source illumination device integrating polarization and structured light according to claim 1, characterized in that, The guide rail (6) is fixed to the light source base (7) and cooperates with the moving mechanism (3) so that the moving mechanism (3) can move horizontally perpendicular to the optical axis.

9. The single-source illumination device integrating polarization and structured light according to claim 1, characterized in that, The aperture of the Lyot depolarizing mirror is not less than the output aperture of the polarization module (4), ensuring that most of the linearly polarized light is incident and depolarized. The aperture of the Lyot depolarizing mirror covers the light-emitting area of ​​the white LED light source.

10. The single-source illumination device integrating polarization and structured light according to claim 2, characterized in that, It also includes a drive control module, which is electrically connected to the LED (4-1), the TN-type LCD box (4-4) and the electric motion mechanism (1), and can output adjustable working voltage and precise pulse signal to realize the automatic control of each device.

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