Dynamic polarization regulation and control system based on liquid crystal phase modulator and laser projection system

Abstract

The invention provides a dynamic polarization regulation and control system based on a liquid crystal phase modulator and a laser projection system, relates to the technical field of laser projection, and aims at solving the problems that an existing laser projection polarization regulation and control scheme is multiple in elements, poor in universality, low and unstable in polarization conversion efficiency and insufficient in dynamic adaptability. The dynamic polarization regulation and control system comprises a multi-channel liquid crystal phase modulator (LCPM) with three channels independently designed, and the multi-channel liquid crystal phase modulator is used for receiving a red light path, a blue light path and a green light path. The driving control module independently regulates and controls each channel, converts red and blue light s polarized light into p polarized light and keeps the p polarization state of green light; the temperature compensation module monitors the temperature of a liquid crystal layer in real time; the driving control module adjusts voltage compensation efficiency attenuation according to a temperature signal; the light path coupling assembly ensures vertical incidence of light beams and calibrates the polarization direction. According to the invention, multiple channels are integrated through a single device, the optical path is simplified, the cost is reduced, laser power fluctuation and environment change are dynamically adapted, the adaptability is high, and the use effect is better.

Description

Technical Field

[0001] This invention relates to the field of laser projection technology, and more specifically, to a dynamic polarization control system and a laser projection system based on a liquid crystal phase modulator. Background Technology

[0002] In laser projection technology, red and blue lasers typically output s-polarized light, while green lasers typically output p-polarized light. The differences in polarization characteristics between different laser colors need to be unified through polarization modulation to improve beam combining efficiency and light utilization. Existing polarization modulation schemes mostly employ a fixed combination of a polarization beam splitter (PBS) and a quarter-wave plate, converting non-target polarized light to target polarized light by preset wave plate angles. However, this approach has the following significant drawbacks: First, the components have poor versatility and high cost: the red, blue, and green optical paths require separate PBS and waveplates with different parameters, resulting in a large number of components with low versatility, which increases the complexity of optical path design and production assembly costs. Second, the polarization conversion efficiency is low and unstable: static components cannot compensate for the effects of laser power fluctuations, wavelength drift, and changes in ambient temperature, and the polarization conversion efficiency is usually only 85%-90%. Long-term operation is prone to uneven screen brightness due to efficiency decay. At the same time, the dynamic adaptability is poor. For systems that require automatic brightness adjustment and multi-mode projection switching, the static polarization structure cannot adjust the polarization state in real time, which limits the system's functional expansion and flexibility.

[0003] Therefore, there is an urgent need to design a polarization control scheme that can adapt to multicolor lasers, dynamically compensate for polarization efficiency, and simplify the optical path structure to solve the above problems. Summary of the Invention

[0004] The present invention aims to solve the problems of existing laser projection polarization control schemes, such as numerous components, poor versatility, low and unstable polarization conversion efficiency, and insufficient dynamic adaptability.

[0005] To address the aforementioned problems, this invention provides a dynamic polarization control system based on a liquid crystal phase modulator, comprising: a multi-channel liquid crystal phase modulator, wherein the multi-channel liquid crystal phase modulator adopts a three-channel independent control design for receiving red, blue, and green light paths; and a drive control module, wherein the drive control module is connected to the multi-channel liquid crystal phase modulator for outputting a continuously adjustable voltage, supporting independent voltage settings for the red, blue, and green channels, controlling the alignment state of liquid crystal molecules, and utilizing the liquid crystal electro-controlled birefringence effect to dynamically convert the s-polarized light of red and blue light into p-polarized light, while simultaneously stabilizing the p-polarized light of green light. The system includes: a temperature compensation module for real-time monitoring of the liquid crystal layer temperature of the multi-channel liquid crystal phase modulator; a temperature signal transmission to the drive control module for signal interaction to establish a temperature-voltage compensation lookup table; and an optical path coupling component for ensuring that the light beam is perpendicularly incident on the multi-channel liquid crystal phase modulator and calibrating the polarization direction when the light beam exits the multi-channel liquid crystal phase modulator to ensure that the three colors of light are all in a p-polarized state for subsequent beam combining, thus completing subsequent imaging and projection.

[0006] The dynamic polarization control system based on a liquid crystal phase modulator provided by this invention has, but is not limited to, the following beneficial effects compared to existing technologies: To address the problems of existing laser projection polarization control schemes, such as numerous components, poor versatility, low and unstable polarization conversion efficiency, and insufficient dynamic adaptability, this system uses a multi-channel liquid crystal phase modulator horizontally mounted in the center of the optical path. The drive control module is electrically connected to the multi-channel liquid crystal phase modulator via a ribbon cable. A temperature compensation module monitors the surface temperature of the liquid crystal layer of the multi-channel liquid crystal phase modulator and communicates with the drive control module. An optical path coupling component ensures the beam is perpendicularly incident on the multi-channel liquid crystal phase modulator and calibrates the polarization direction as the beam exits, ensuring that all three colors are in a p-polarized state for subsequent beam recombination. In operation, after the laser source's mixed beam is separated into three colors, it is perpendicularly incident on the corresponding channel of the multi-channel liquid crystal phase modulator under the action of the optical path coupling component. The drive control module outputs an independent voltage to regulate the alignment of the liquid crystal molecules, converting red and blue s-polarized light into p-polarized light while maintaining the green light in a p-polarized state. The temperature compensation module... The system monitors the temperature of the liquid crystal layer, and the drive control module adjusts the voltage based on the temperature signal to compensate for efficiency attenuation. The output light from the multi-channel liquid crystal phase modulator is then calibrated for polarization direction by an optical path coupling component to ensure that all three colors of light are combined in a p-polarized state for subsequent imaging and projection. By using a multi-channel liquid crystal phase modulator, corresponding to the red, blue, and green light paths respectively, a single device replaces the traditional three sets of PBS and waveplates, simplifying the optical path structure and facilitating the miniaturization of the projection system. The drive control module provides a high-precision adjustable voltage of 0-10V, independently controlling the arrangement of liquid crystal molecules in each channel, and using the electronically controlled birefringence effect to achieve polarization state conversion, adapting to power fluctuations. The temperature compensation module monitors the liquid crystal layer temperature of the multi-channel liquid crystal phase modulator in real time, and the drive control module adjusts the voltage based on the temperature signal to compensate for efficiency attenuation and ensure stability. Moreover, the system can be connected in series with existing projection systems without modifying the original imaging and lens structure, making it highly adaptable and providing better performance.

[0007] Furthermore, the three independent channels of the multi-channel liquid crystal phase modulator correspond to the wavelengths of red, blue, and green light, respectively, and the size of each channel matches the spot size of the corresponding output beam.

[0008] Furthermore, a physical isolation layer is provided between the three independent channels of the multi-channel liquid crystal phase modulator, and the material of the physical isolation layer is high-temperature resistant quartz glass, which is used to prevent light from crossing between channels.

[0009] Furthermore, the drive control module includes a drive chip, which integrates a three-channel DAC voltage output unit with an output voltage range of 0-10V and a voltage regulation accuracy of 0.01V. It pre-stores the reference voltage parameters of the red, blue, and green channels under a standard environment of 25℃, and automatically loads the reference parameters after power-on. It supports communication with the temperature compensation module and automatically calls the pre-stored temperature compensation coefficient after receiving the temperature signal.

[0010] Furthermore, the temperature compensation module includes a temperature sensor, which is positioned close to the liquid crystal layer of the multi-channel liquid crystal phase modulator for real-time monitoring of the liquid crystal layer temperature.

[0011] Furthermore, the specific temperature and voltage compensation coefficients established between the temperature compensation module and the drive control module are as follows: when the temperature changes within the temperature range, the drive control module automatically adjusts the voltage of each channel according to the pre-stored segmented compensation coefficients. For every 5°C increase in temperature, the voltage of the red and blue channels increases by 0.2V, while the voltage of the green channel remains unchanged, in order to offset the attenuation of polarization conversion efficiency caused by temperature changes and laser power fluctuations.

[0012] Furthermore, the optical path coupling assembly includes a polarization-preserving fiber adapter, a collimating lens, and an analyzer. The polarization-preserving fiber adapter is used to receive the separated three-color beams and, in conjunction with the collimating lens, to make the beams perpendicularly incident on the input side of the multi-channel liquid crystal phase modulator. The beams output from the output side of the multi-channel liquid crystal phase modulator are polarized by the analyzer.

[0013] Furthermore, the polarization-maintaining fiber optic adapter uses an FC / PC interface to adapt to the laser source output end, ensuring that the polarization state of the incident beam does not undergo additional changes.

[0014] Furthermore, the collimating lens of the optical path coupling component is an aspherical lens made of glass with a focal length of 10mm and an aperture of 5mm, which collimates the diverging beam output from the optical fiber into parallel light with an incident angle deviation of ≤1°. The distance between the analyzer and the output side of the multi-channel liquid crystal phase modulator is 5-8mm to ensure that the beam passes perpendicularly through the analyzer.

[0015] The present invention also provides a laser projection system, including the dynamic polarization control system based on a liquid crystal phase modulator as described above, and further including a laser light source group, a beam splitter prism, a beam combiner prism, and an imaging module. The laser light source group is used to emit light to the beam splitter prism. The dynamic polarization control system is connected in series between the beam splitter prism and the beam combiner prism of the laser projection system. Its input end is connected to the three-color light output end of the beam splitter prism, and its output end is connected to the input end of the beam combiner prism. The output end of the beam combiner prism is connected to the imaging module, without changing the structure of the imaging module and the projection lens of the laser projection system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a laser projection system including a dynamic polarization control system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the dynamic polarization control system based on a liquid crystal phase modulator according to an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Multi-channel liquid crystal phase modulator; 2. Drive control module; 3. Temperature compensation module; 4. Polarization-maintaining fiber optic adapter; 5. Collimating lens; 6. Analyzer; 7. Laser source group; 8. Beam splitter prism; 9. Beam combiner prism; 10. Imaging module. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", 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 this 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 this invention.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0023] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] See Figures 1-2 The dynamic polarization control system based on a liquid crystal phase modulator according to an embodiment of the present invention includes: a multi-channel liquid crystal phase modulator 1, wherein the multi-channel liquid crystal phase modulator 1 adopts a three-channel independent control design for receiving red, blue, and green light paths; and a drive control module 2, wherein the drive control module 2 is connected to the multi-channel liquid crystal phase modulator 1 for outputting a continuously adjustable voltage, supporting independent voltage settings for the red, blue, and green channels, controlling the alignment state of liquid crystal molecules, and utilizing the liquid crystal electro-controlled birefringence effect to dynamically convert the s-polarized light of red and blue light into p-polarized light, while simultaneously maintaining the p-polarized light of green light stably. Temperature compensation module 3 is used to monitor the temperature of the liquid crystal layer of the multi-channel liquid crystal phase modulator 1 in real time. The temperature signal is transmitted to the drive control module 2, and the two modules interact to establish a temperature and voltage compensation lookup table. The drive control module 2 adjusts the voltage according to the temperature signal to compensate for the attenuation of polarization conversion efficiency. Optical path coupling component is used to make the light beam perpendicular to the multi-channel liquid crystal phase modulator 1 and to calibrate the polarization direction when the light beam exits the multi-channel liquid crystal phase modulator 1, so as to ensure that the three colors of light are all in the p-polarized state for subsequent light combination, and to complete the subsequent imaging and projection.

[0025] In this embodiment, addressing the problems of existing laser projection polarization control schemes such as numerous components, poor versatility, low and unstable polarization conversion efficiency, and insufficient dynamic adaptability, the multi-channel liquid crystal phase modulator 1 in this system is horizontally mounted in the center of the optical path. The drive control module 2 is electrically connected to the multi-channel liquid crystal phase modulator 1 via a ribbon cable. The temperature compensation module 3 is used to monitor the surface temperature of the liquid crystal layer of the multi-channel liquid crystal phase modulator 1 and communicate with the drive control module 2. The optical path coupling component is used to ensure that the light beam is perpendicularly incident on the multi-channel liquid crystal phase modulator 1 and to calibrate the polarization direction when the light beam exits through the multi-channel liquid crystal phase modulator 1, ensuring that the three colors of light are all in the p-polarized state for subsequent light combination. In use, after the laser source mixed beam is separated into three colors of light, it is perpendicularly incident on the corresponding channel of the multi-channel liquid crystal phase modulator 1 under the action of the optical path coupling component. The drive control module 2 outputs an independent voltage to regulate the alignment of liquid crystal molecules, converting the red and blue s-polarized light into p-polarized light and maintaining the green light in the p-polarized state. The temperature compensation module 3 monitors the temperature of the liquid crystal layer, and the drive control module 2 adjusts the voltage according to the temperature signal to compensate for efficiency attenuation. The output light of the multi-channel liquid crystal phase modulator 1 is then... The polarization direction is calibrated through the optical path coupling component to ensure that all three colors of light are combined in the p-polarized state for subsequent imaging and projection. The multi-channel LCPM-based multi-color polarization independent control structure integrates three independent channels into a single device. Utilizing the liquid crystal electro-controlled birefringence effect, it achieves dynamic conversion of red and blue light from s-polarization to p-polarization and stable maintenance of green light p-polarization. This allows for adaptation to the polarization differences of the three laser colors without replacing components, simplifying the optical path structure and facilitating miniaturization of the projection system. The drive control module 2 provides a 0-10V high-precision adjustable voltage, independently controlling each channel. The system features a liquid crystal molecule arrangement, combined with high-precision temperature detection and independent voltage adjustment. By pre-stored segmented compensation coefficients, it quickly offsets the efficiency degradation caused by temperature and power fluctuations, ensuring that the full-color polarization conversion efficiency remains stable at over 95%. The temperature compensation module 3 monitors the liquid crystal layer temperature of the multi-channel liquid crystal phase modulator 1 in real time, and the drive control module 2 adjusts the voltage according to the temperature signal to compensate for efficiency degradation and ensure stability. Furthermore, this system can be directly embedded into the beam splitting and combining optical paths of a laser projection system without modifying the original imaging and projection modules, achieving high adaptability and mass production capability, resulting in better performance.

[0026] Optionally, the three independent channels of the multi-channel liquid crystal phase modulator 1 (LCPM) correspond to the wavelengths of red, blue, and green light, respectively, and the size of each channel matches the spot size of the corresponding output beam.

[0027] In this embodiment, the three independent channels of the LCPM are respectively matched with the wavelength characteristics of red, blue, and green lasers, and are matched with the spot size of the output beam to ensure that the beam completely covers the channel; the polarization conversion characteristics of different wavelength lasers are different, and the targeted channel design ensures that each color beam can obtain the best polarization conversion efficiency, avoiding efficiency loss due to wavelength mismatch; the channel size is matched with the spot size to ensure that the beam has no leakage or obstruction.

[0028] Optionally, the three independent channels of the multi-channel liquid crystal phase modulator 1 (LCPM) are provided with a physical isolation layer, and the material of the physical isolation layer is high-temperature resistant quartz glass, which is used to prevent light from crossing between channels.

[0029] In this embodiment, the physical barrier layer between the three LCPM channels is 0.5mm thick and flush with the channel edge. The quartz glass barrier layer has good optical insulation and high temperature resistance, which can block beam crosstalk between adjacent channels and avoid deformation of the barrier layer caused by temperature rise, ensuring channel independence, no cross interference, improved polarization conversion accuracy, improved color purity of the image, and avoidance of stray light influence.

[0030] Optionally, the drive control module 2 includes a drive chip, which integrates a three-channel DAC voltage output unit with an output voltage range of 0-10V and a voltage regulation accuracy of 0.01V. It pre-stores the reference voltage parameters of the red, blue, and green channels under a standard environment of 25℃, and automatically loads the reference parameters after power-on. It supports communication with the temperature compensation module 3 and automatically calls the pre-stored temperature compensation coefficient after receiving the temperature signal.

[0031] In this embodiment, the core of the drive control module 2 is a dedicated drive chip, which integrates three DAC voltage output units. Each output is independently adjustable, with a voltage range of 0-10V and an adjustment accuracy of 0.01V. The chip pre-stores the three-color channel reference voltage under a standard 25℃ environment, which is automatically loaded after power-on. It supports continuously adjustable voltage and can adapt to laser power fluctuations and multi-mode projection switching (such as standard mode and energy-saving mode) in real time, expanding the functional boundaries of the system. At the same time, it communicates with the temperature compensation module 3 through the I2C interface. The reference voltage ensures that the initial polarization conversion efficiency meets the standard, and the voltage adjustment accuracy of 0.01V can realize fine adjustment of the polarization state to adapt to laser power fluctuations. The communication function with the temperature compensation module 3 enables the voltage to be dynamically adjusted according to the temperature, avoiding efficiency decay.

[0032] Optionally, the temperature compensation module 3 includes a temperature sensor, which is disposed close to the liquid crystal layer of the multi-channel liquid crystal phase modulator 1 for real-time monitoring of the liquid crystal layer temperature.

[0033] In this embodiment, the temperature sensor is a high-precision digital sensor, which is attached to the surface of the liquid crystal layer of the LCPM with thermally conductive adhesive. The sensor leads are connected to the signal input terminal of the drive control module 2. The sampling interval is 1 second, and the detection accuracy is ±0.5℃. The arrangement of liquid crystal molecules is sensitive to temperature, and temperature changes will cause the polarization conversion efficiency to decay. The temperature sensor collects the temperature of the liquid crystal layer in real time and transmits the digital signal to the drive control module 2 to provide a basis for voltage adjustment. The temperature detection response is rapid and can capture temperature changes as small as 0.5℃, providing data support for accurate compensation and avoiding efficiency fluctuations caused by temperature.

[0034] Optionally, the temperature and voltage compensation coefficients established by the temperature compensation module 3 and the drive control module 2 are as follows: when the temperature changes within the temperature range, the drive control module 2 automatically adjusts the voltage of each channel according to the pre-stored segmented compensation coefficients. For every 5°C increase in temperature, the voltage of the red and blue channels increases by 0.2V, while the voltage of the green channel remains unchanged, in order to offset the attenuation of polarization conversion efficiency caused by temperature changes and laser power fluctuations.

[0035] In this embodiment, the drive control module 2 pre-stores segmented temperature and voltage compensation coefficients. The core compensation logic is as follows: for every 5°C increase in temperature, the red and blue channel voltages increase by 0.2V, while the green channel voltage remains unchanged; when the temperature decreases, the red and blue channel voltages are reduced by the same amount; the polarization conversion efficiency of red and blue light is more significantly affected by temperature, while green light is relatively stable, and targeted compensation can accurately offset the efficiency decay; the segmented compensation coefficients are preset based on a large amount of experimental data to ensure compensation accuracy; within the operating temperature range of -10°C to 50°C, the polarization conversion efficiency fluctuation is ≤1%, solving the temperature sensitivity problem of traditional solutions and adapting to different environments.

[0036] Optional, please refer to Figure 1 The optical path coupling assembly includes a polarization-preserving fiber adapter 4, a collimating lens 5, and an analyzer 6. The polarization-preserving fiber adapter 4 is used to receive the separated three-color beams and, together with the collimating lens 5, ensures that the beams are perpendicularly incident on the input side of the multi-channel liquid crystal phase modulator 1. The beams output from the output side of the multi-channel liquid crystal phase modulator 1 are polarized by the analyzer 6. The polarization-preserving fiber adapter 4 uses an FC / PC interface to adapt to the output end of the laser source and is used to ensure that the polarization state of the incident beam does not undergo additional changes.

[0037] In this embodiment, the polarization-preserving fiber adapter 4 is installed at the output end of the beam splitter 8 and connected to the polarization-preserving fiber adapter 4 via an FC / PC interface. The collimating lens 5 is installed on the output side of the polarization-preserving fiber adapter 4, with a distance of 15mm from the input side of the LCPM. The analyzer 6 is installed on the output side of the LCPM, with a distance of 6mm from the LCPM. The polarization-preserving fiber adapter 4 ensures that the polarization state of the beam does not undergo additional changes during transmission. The collimating lens 5 converts the diverging beam into parallel light, achieving perpendicular incidence on the LCPM. The analyzer 6 filters out incompletely converted polarized light and calibrates it to a uniform p-polarization state, providing a stable basis for subsequent conversion.

[0038] Optionally, the collimating lens 5 of the optical path coupling assembly is an aspherical lens made of glass with a focal length of 10mm and an aperture of 5mm, which collimates the diverging beam output from the optical fiber into parallel light with an incident angle deviation of ≤1°. The distance between the analyzer 6 and the output side of the multi-channel liquid crystal phase modulator 1 is 5-8mm to ensure that the beam passes perpendicularly through the analyzer 6.

[0039] In this embodiment, the collimating lens 5 is an aspherical lens made of glass with a focal length of 10mm, an aperture of 5mm, and a numerical aperture of 0.25. It collimates the diverging beam output from the optical fiber into parallel light with a parallelism error ≤0.1°. The analyzer 6 is a Glan-Taylor prism with a light-transmitting aperture of 12mm and a distance of 6mm from the output side of the LCPM, ensuring that the beam completely covers the light-transmitting area of ​​the analyzer 6. Compared with a spherical lens, the aspherical lens has a better collimation effect, which can reduce spherical aberration and ensure that the beam is perpendicularly incident on the LCPM. The reasonable distance between the analyzer 6 and the LCPM avoids beam obstruction and ensures polarization calibration effect.

[0040] Another embodiment of the present invention provides a laser projection system, including the dynamic polarization control system based on a liquid crystal phase modulator as described above, and further including a laser light source group 7, a beam splitter 8, a beam combiner 9, and an imaging module 10. The laser light source group 7 is used to emit light to the beam splitter 8. The dynamic polarization control system is connected in series between the beam splitter 8 and the beam combiner 9 of the laser projection system. Its input end is connected to the three-color light output end of the beam splitter 8, and its output end is connected to the input end of the beam combiner 9. The output end of the beam combiner 9 is connected to the imaging module 10, without changing the structure of the imaging module 10 and the projection lens of the laser projection system.

[0041] In this embodiment, the dynamic polarization control system is connected in series between the beam splitting and beam combining stages. It receives the separated three-color light, completes polarization control, and delivers it to the beam combining stage. It is seamlessly integrated into the existing projection process without the need to reconstruct the optical path. It can be directly embedded into mainstream laser projection systems such as DLP and LCD. The mass production calibration process is simplified, it is compatible with existing production lines, and the upgrade cost is reduced.

[0042] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A dynamic polarization control system based on a liquid crystal phase modulator, characterized in that, include: A multi-channel liquid crystal phase modulator (1) is provided, which adopts a three-channel independent control design and is used to receive red, blue and green light paths. The drive control module (2) is connected to the multi-channel liquid crystal phase modulator (1) and is used to output a continuously adjustable voltage. It supports independent voltage settings for red, blue and green channels, regulates the arrangement state of liquid crystal molecules, and uses the liquid crystal electronically controlled birefringence effect to dynamically convert the s-polarized light of red and blue light into p-polarized light, while maintaining the p-polarized light of green light stably. Temperature compensation module (3) is used to monitor the temperature of the liquid crystal layer of the multi-channel liquid crystal phase modulator (1) in real time. The temperature signal is transmitted to the drive control module (2) and interacts with the drive control module (2) to establish a temperature and voltage compensation reference table. The drive control module (2) adjusts the voltage according to the temperature signal to compensate for the attenuation of polarization conversion efficiency. The optical path coupling component is used to make the light beam perpendicularly incident on the multi-channel liquid crystal phase modulator (1) and to calibrate the polarization direction when the light beam exits through the multi-channel liquid crystal phase modulator (1) to ensure that the three colors of light are all in the p polarization state for subsequent light combination, and to complete the subsequent imaging and projection.

2. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 1, characterized in that, The three independent channels of the multi-channel liquid crystal phase modulator (1) correspond to the wavelengths of red light, blue light, and green light, respectively, and the size of each channel matches the spot size of the corresponding output beam.

3. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 2, characterized in that, The multi-channel liquid crystal phase modulator (1) has a physical isolation layer between its three independent channels, and the material of the physical isolation layer is high-temperature resistant quartz glass, which is used to prevent light from crossing between channels.

4. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 1, characterized in that, The drive control module (2) includes a drive chip, which integrates a three-channel DAC voltage output unit with an output voltage range of 0-10V and a voltage regulation accuracy of 0.01V. It pre-stores the reference voltage parameters of the red, blue, and green channels under a standard environment of 25℃. After power-on, it automatically loads the reference parameters and supports communication with the temperature compensation module (3). After receiving the temperature signal, it automatically calls the pre-stored temperature compensation coefficient.

5. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 4, characterized in that, The temperature compensation module (3) includes a temperature sensor, which is set close to the liquid crystal layer of the multi-channel liquid crystal phase modulator (1) and is used to monitor the temperature of the liquid crystal layer in real time.

6. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 5, characterized in that, The specific temperature and voltage compensation coefficients established by the temperature compensation module (3) and the drive control module (2) are as follows: When the temperature changes within the temperature range, the drive control module (2) automatically adjusts the voltage of each channel according to the pre-stored segmented compensation coefficient. For every 5°C increase in temperature, the voltage of the red and blue channels increases by 0.2V, while the voltage of the green channel remains unchanged, in order to offset the attenuation of polarization conversion efficiency caused by temperature changes and laser power fluctuations.

7. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 1, characterized in that, The optical path coupling assembly includes a polarization-maintaining fiber adapter (4), a collimating lens (5), and an analyzer (6). The polarization-maintaining fiber adapter (4) is used to receive the separated three-color beams and, together with the collimating lens (5), make the beams perpendicularly incident on the input side of the multi-channel liquid crystal phase modulator (1). The beams output from the output side of the multi-channel liquid crystal phase modulator (1) are polarized by the analyzer (6).

8. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 7, characterized in that, The polarization-maintaining fiber optic adapter (4) uses an FC / PC interface to adapt to the output end of the laser source, ensuring that the polarization state of the incident beam does not undergo additional changes.

9. The dynamic polarization control system based on a liquid crystal phase modulator according to claim 8, characterized in that, The collimating lens (5) of the optical path coupling component is an aspherical lens made of glass with a focal length of 10mm and an aperture of 5mm. It collimates the diverging beam output from the optical fiber into parallel light with an incident angle deviation of ≤1°. The distance between the analyzer (6) and the output side of the multi-channel liquid crystal phase modulator (1) is 5-8mm to ensure that the beam passes perpendicularly through the analyzer (6).

10. A laser projection system, characterized in that, The dynamic polarization control system based on a liquid crystal phase modulator as described in any one of claims 1-9 further includes a laser light source group (7), a beam splitter (8), a beam combiner (9), and an imaging module (10). The laser light source group (7) is used to emit light to the beam splitter (8). The dynamic polarization control system is connected in series between the beam splitter (8) and the beam combiner (9) of the laser projection system. The input end is connected to the three-color light output end of the beam splitter (8), and the output end is connected to the input end of the beam combiner (9). The output end of the beam combiner (9) is connected to the imaging module (10). The structure of the imaging module (10) and the projection lens of the laser projection system is not changed.

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